december 20-22, 2012 sousse tunisia2012.irec-conference.com/files/final_proceedings.pdf · pr....

i

The Fourth International

Renewable Energy Congress

December 20-22, 2012 Sousse – Tunisia

www.irec.cmerp.net

Organized by:

University of Sfax, Tunisia

National Engineering School of Sfax

Research unit: Machines control and Power Grid

The Fourth International Renewable Energy Congress

December 20-22, 2012 – Sousse, Tunisia

i

EDITORIAL BOARD

Honorary Chairman: Mohamed Ben Ali Kamoun, Tunisia

General Chairman: Maher Chaabene, Tunisia

Publication committee

Dr. Mohsen BEN AMMAR (Tunisia), Chairman

Sahbi MOALLA (Tunisia)

Kamel MKAOUAR (Tunisia)

Othman HINDAOUI (Tunisia)

Financial committee

Dr. Souhir SALLEM (Tunisia), Chairman

NaissenMASMOUDI (Tunisia)

Amal MARREKCHI (Tunisia)

SoulaymenKAMMOUN (Tunisia)

Technical committee

Pr. Zied CHTOUROU (Tunisia), Chairman

Dr. KhaledTAOUIL(Tunisia)

Mohmoud AMMOUS (Tunisia)

Fathi BEN ABDALLAH (Tunisia)

Wassim KHANFIR (Tunisia)

International advisory committee

Pr. FERNANDO TADEO (Spain), Chairman

Pr. ZekaiI ŞEN (Turkey)

Pr. Jose BOAVENTURA RIBEIRO DA CUNHA (Portugal)

Pr. Abdeslam MENIAI (Algeria)

Pr. Djamila REKIOUA (Algeria)

Pr. Mohamed FAISAL (Libya)

Pr. Mohamed HABIB SELLAMI (Tunisia)

Pr. Eduardo MAXIMINO SANCHEZ CERVANTES (Mexico)

Pr. Reinhard HAAS (Austria)

Pr. Harold P. SJURSEN (USA)

Pr. Ahmed HARB (Jordan)

Pr. Giuseppe TINA (Italy)

Pr. Antonio GAGLIANO (Italy)



ii

Editors of the partner journals

AlintiSümerŞahin (Turkey)

Energy Conversion and Management (EC&M)

E.A. Veziroglu (USA)

International Journal of Hydrogen Energy (IJHE)

PandianVasant (Malaysia)

International Journal of Energy Optimization and Engineering (IJEOE)

Ahmed Zobaa (UK)

International Journal of Renewable Energy Technology (IJRET )

Nasr Alkadi (USA)

International Journal of Energy Technology and Policy (IJETP)

HameedMetghalchi (USA)

Journal of Energy Resources Technology (JERT)



iii

SPONSORS



iv

PREFACE

The production and use of renewable energies have grown more quickly

in recent years due to higher prices for of and natural gas and also to

states incentives.The use of renewable energies is expected to continue

to grow over the next years, although we will still rely on non-renewable

energies to meet most of our energy needs.

The International Renewable Energy Congress (IREC) provides a forum

for researchers and practitionersaround the world on recent

developments in the fields of renewable energy. The congress consists

of keynote sessions, oral sessions and poster presentations. Considered

as a catalyst for research works, IREC 2012hasfacilitated the selection of

65% among accepted papers for possible publication in six partner

journals, namely: EC&M,IJHE, IJRET, IJEOE, IJETP and JERT.

SCOPES

Wind Energy Energystorage

PhotovoltaicEnergy Energytransfer

Solar Thermal Energy Modeling and simulation

HybridEnergy Policies and regulation

BiomassEnergy Optimization

HydraulicEnergy Energysaving

NuclearEnergy Energy management

HydrogenEnergy Instrumentation & Control

Sustainability Prediction and forecast

Environment System sizing

Materials& technologies EnergyEfficiency

Smart grids Fuel cells



v

Keynotes

Keynote 1: Promotion of renewable energy for water production through

desalination

G. Zaragoza

CIEMAT-Plataforma Solar de Almería, Almería, Spain

Abstract: The European project ProDes (Promotion of Renewable Energy for

Water Production through Desalination), financed through the Intelligent Energy

Europe programme, was developed with the objective of supporting the use of

renewable energy to power desalination, either in stand-alone or grid connected

systems, with the aim of providing better load control and consequently wider

use of renewable energy. The specific objectives of the project were: (i) to bring

together the actors of desalination and renewable energies and coordinate their

activities; (ii) to lay the foundation for training specialists in desalination with

renewable energy; (iii) to help the technology providers to reach their niche

markets; (iv) to facilitate the flow of capital for product and project

development; (v) to improve regulatory framework conditions; and (vi) to raise

awareness of the technology. These were achieved in four main phases. One

phase focused on the education system and the academic community,

developing a course which was implemented in four countries with an e-learning

option which is still ongoing. Another phase facilitated communication

organizing networking sessions between the industry, investors and SMEs on

the local level, and performing an analysis of the European and export markets

to help companies plan their growing strategies. A third phase concentrated on

the framework conditions and how they can affect the implementation of RE-

desalination, defining targets for the share of water produced by RE-desalination

and suggestions for subsidy schemes. Also, general awareness about the benefits

of the technology was raised using the internet and the media.

The project and its different phases of implementation are presented, focusing

on its main outcomes. One of the most important results of the ProDes project is

a roadmap for renewable energy (RE) desalination. It includes a review of the

current status of the technology, the perspectives of the development, the

barriers that hinder it, the strategy to overcome them, and the resources needed

for the implementation of the technology. The roadmap is extensively discussed,

with special focus on the description of the different technologies available and

their current status of implementation, the main targets of development and the

strategy to achieve them. Also, the future activities based on the successful

experiences obtained in the project will be presented.



vi

Keynote 2: Solar Heating and Cooling - State of the Art and Research

Trends

Dr.-Ing. Peter Schossig

Fraunhofer-InstitutfürSolareEnergiesysteme ISE, Freiburg, Germany

e-mail: [email protected]

Abstract –More than 40 percent of the final energy in Europe is used in the

building sector, mainly for heating and cooling and domestic hot water. To

convert our energy systems towards sustainability, we will have to cover a

significant share of this amount with renewable energy sources. Solar thermal

systems can be used efficiently for both: the heating and the cooling of

buildings.

A holistic approach to energy efficient buildings has four elements:

1. the reduce of the energy demand by passive means, e.g. insulated building

envelopes, efficient shading devices or passive ventilation;

2. the use of environmental sources like ground or ambient air to cover the

demand directly;

3. the application of efficient energy conversion, e.g. heat pumps or combined

heat and power instead of simple boilers and

4. the covering of the remaining energy demand with renewable energy sources.

To achieve the last objective, solar energy is one of the possible means among

biomass, wind or other sources. Especially for the heat demand of buildings and

for air conditioning systems, solar thermal systems are an interesting and

efficient option.

A variety of different solutions is available to produce heat from solar irradiation

and to convert this into cold within solar thermal cooling systems.

One great advantage of thermal systems is the use of thermal energy storages to

match supply and demand in time, which is especially important for the

fluctuating nature of renewable sources like solar irradiation. Several

technologies can be used for different applications to store thermal energy in a

compact way and over a longer period of time.

The presentation will give an overview about the state of the art of existing

technologies for solar thermal heating and cooling with the focus on solar

thermal cooling and thermal energy storage. It also points out the research trends

for future systems.

Keywords: solar heating, solar cooling, thermal energy, energy storage



vii

Keynote 3: TROPOS: A multi-use offshore platform as integrator of clean

energy, seafood production, transport and leisure

Eric Delory, Dr.-Ing.

Oceanic Platform of the Canary Islands, Ctra de Taliarte s/n, TELDE 35200,

SPAIN

Abstract:

The TROPOS project, coordinated by PLOCAN and co-funded by the Ocean of

Tomorrow under the European Commission Seventh Framework Programme,

responds to a request to design innovative platforms located offshore and able to

produce clean energy, food, as well as offer maritime services in a sustainable

way, with a focus on Mediterranean, subtropical and tropical regions. TROPOS,

which gathers 18 academic and industrial partners, aims to create an innovative

design of a modular floating platform, adapted to deep waters and capable of

integrating the exploitation of oceanic resources including energy, aquaculture,

maritime transport, recreational and oceanic observation activities. Two other

projects, named MERMAID and H2OCEAN, will offer design alternatives and

it has been decided that the three projects will work in synergy in order to

optimize the potential and expertise towards turning these designs into viable

solutions. Building a technical demonstrator is clearly the next phase and areas

for deployment and exploitation are to be decided according to regional interests

and necessities. Such initiatives are clearly responding to the lemma <<think

globally, act locally>> and will be proposed as cost-efficient integrators of

marine renewable energies structures.



viii

Plenary session: Thermionic Nuclear and Solar Conversion for Space

Vehicles

Sümer ŞAHİN

Atılım University, Faculty of Engineering, 06836 İncek, Gölbaşı, Ankara,

TÜRKİYE

E-mail: [email protected];

For world energy needs in near near to intermediate future, on can state that

solar electricity production in space has great potential, due to the practically

continuous and considerably higher availability of solar radiation energy at a

power level of 1350 W/m2 at Earth orbit. At present, solar cell panels deliver

electricity for space crafts. However, weight & cost to electrical power ratio are

low to justify applying the solar cells for high energy needs, which will be

required for space industry. On the other hand, there are other means for direct

conversion of solar energy into electricity, namely;Thermo-electric conversion,

Thermionic conversion.Both technologies have been successfully and widely

used in space nuclear reactors since 60’s. In this work, main technical data of

extra-light parabolic Fresnel mirror reflectors for solar thermionic electricity

generation will be shortly outlined.In the second part of the work, the neutronic

analysis of a uranium oxide (UO2) fueled in-core thermionic space craft nuclear

thermal reactor for electricity generation as well as the thermo-hydrodynamic

analysis will be outlined for a fast, uranium carbide (UC) fueled in-core

thermionic space craft nuclear reactor, designed both for electricity generation

and nuclear thermal propulsion. Being a very compact critical assembly, the

reactor has an extremely high neutron leakage. Thus, the reactor control can be

performed, elegantly, through the manipulation of the radial neutron leakage

with the help of the rotating reflector drums containing natural B4C neutron

absorbers, either in form of segments or strips. Calculations with natural B4C

segments imbedded in rotating beryllium drums in the radial reflector have

shown that reflector drums with 100 % natural B4C in form of strips (drum

diameter = 13.5 cm, strip width = 5 mm) at the outer periphery of the radial

reflector of 16 cm thickness would make possible reactivity changes of

keff,max = 10.7 % without a significant distortion of the heat generation

during all phases of the space mission. A reduction of the B4C in the strips to 20

and 10 % would still allow a reactivity change of keff,max = 8.4 and 7.7 %,

respectively, amply sufficient for an effective control of a fast reactor during all

phases of the space mission. By a nuclear thermal thrust around F = 5000 N and

a specific impulse of 670 sec-1 at an hydrogen exit temperature around 1900 K,

the maximum temperature in the drums rises to 1023 oK, with 100 % natural

B4C content in the strips, far below the melting point of beryllium. The

maximum drum temperature is depressed to 663 and 519 K, with 20 and 10 %

natural B4C content in the strips, respectively.

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia

Table of contents

ID Title / Session Code Page

Wind and Hybrid Energy 'WHE' 1

2

54 Induction generator controlled by a modulated hysteresis direct torque control (MHDTC) in a wind conversion system

IREC2012-WHE-54/O

4

55 Maximizing wind power based on double-fed asynchronous generator by fuzzy logic

IREC2012-WHE-55/P

5

60 Techno-economical study of hybrid power system for refrigeration applications in the arid region in Algeria

IREC2012-WHE-60/O

6

62 Analyze Unsteady Flow 3D around a Blade Rotor of Horizontal Axis Wind Turbine

IREC2012-WHE-62/O

7

73 Lightning damage on the wind power generation systems (study and simulation)

IREC2012-WHE-73/O

8

78 The digital energy management of a stand-alone hybrid system (photovoltaic & wind)

IREC2012-WHE-78/O

9

104 Power maximization of an asynchronous wind turbine with a variable speed feeding a centrifugal pump

IREC2012-WHE-104/O

10

131 Steady and unsteady combined numerical methods applied in HAWT dynamic stall simulation

IREC2012-WHE-131/O

12

200 Realization of wind emulator and Control of a Wind Turbine Connected to the Grid by Using PMSG

IREC2012-WHE-200/O

13

216 Optimal allocation and design of grid connected hybrid systems

IREC2012-WHE-216/P

14

229 Using a DFIG based Wind Turbine for Grid Current Harmonics Filtering

IREC2012-WHE-229/O

15

235 The performance of the H-Savonius combine machine

IREC2012-WHE-235/O

16

247 Influence of Rated Wind Speed on the Energy Yield at a Site

IREC2012-WHE-247/O

17

261 Wind farm power forecasting IREC2012-WHE-261/P

18

266 Wind Turbine Powers Control Using Fuzzy Logic Controllers

IREC2012-WHE-266/O

19

276 Relationship between open angle and aerodynamic performances of a Diffuser Augmented Wind Turbine ‘DAWT’

IREC2012-WHE-276/O

21


280 Realization and control of a wind turbineconnected to the grid by using PMSG

IREC2012-WHE-280/O

22

283 Power Control of a Wind generator connected to the network in front of Strong winds

IREC2012-WHE-283/P

23

313 A fuzzy controlled scheme for hybrid photovoltaic-diesel pumping system

IREC2012-WHE-313/O

24

338 Modeling and control of brushless doubly-fed induction generators in wind energy applications

IREC2012-WHE-338/O

25

357 Direct torque control of grid connected doubly fed induction generator for the wind energy conversion

IREC2012-WHE-357/O

26

362 A LOLP-based method to evaluate the contribution of wind generation to power system adequacy

IREC2012-WHE-362/O

27

377 Wake structure of a horizontal-axis wind turbine IREC2012-WHE-377/O

28

390 Thermo-economic modeling of renewable energy systems. Case study for wind farm

IREC2012-WHE-390/O

29

395 Sensorless decoupled power control scheme of grid connected variable speed wind turbine generator based on modified Phase Locked Loop ‘MPLL’

IREC2012-WHE-395/O

30

398 Analysis of Three Phase Matrix converter fed inductive load for different output frequency

IREC2012-WHE-398/O

31

401 Performance improvement of matrix converters under disturbed input voltage conditions

IREC2012-WHE-401/O

32

403 Backpropagation algorithm for diagnosis of induction machine faults

IREC2012-WHE-403/P

33

413 Evaluation of wind power production prospective at Baburband, Sindh Pakistan

IREC2012-WHE-413/O

35

36

Photovoltaic Energy 'PVE' 37

38

24 Growth Mechanism and Optical Properties of Zinc Oxide Thin Film

IREC2012-PVE-24/O

39

25 Electrical and structural properties of radio frequency (RF) sputtered ZnO thin film at low substrate temperature

IREC2012-PVE-25/O

40

52 The effect of thickness on optical band gap and N-type conductivity of CuInS2 thin films annealed in air atmosphere

IREC2012-PVE-52/P

42

97 The efficiency and economic of photovoltaic panel as shading devices

IREC2012-PVE-97/P

45


98 MPPT-based fuzzy logic controller under partially shaded photovoltaic arrays

IREC2012-PVE-98/O

46

103 Sliding mode control of an active filter for grid connected PV system based on 3-level H-Bridge inverter

IREC2012-PVE-103/O

47

105 Comparative study of the Moroccan power grid reliability in presence of photovoltaic and wind generation

IREC2012-PVE-105/O

48

137 Validation of a laboratory-scale protocol to study the performances of NiO/NiAl2O4 in fixed bed reactor for CLC process

IREC2012-PVE-137/O

49

144 Control of induction motor pumping system supplied by a photovoltaic generator

IREC2012-PVE-144/O

50

182 PV Maximum Power Point Tracking under rapidly changing irradiance: control scheme investigation

IREC2012-PVE-182/O

53

205 Application of the particle swarm optimization algorithm "PSO" and five levels inverter in a photovoltaic water pumping system

IREC2012-PVE-205/P

56

210 A non linear control of photovoltaic system based on discrete sliding mode

IREC2012-PVE-210/O

57

230

Effect the thickness and bending angle as a function on electrical resistance of Aluminum thin films deposited on Flex and Tedlar (TPT) flexible substrates for solar cell

IREC2012-PVE-230/P

58

238 Determination of the monthly and yearly electrical output power of a PV panel using a Robot Manipulator for sun tracking

IREC2012-PVE-238/O

59

251 Experimentation and performances of a PV water pumping system

IREC2012-PVE-251/O

60

254 A Modern MPPT Control Algorithm Based on alpha-MPP Pass-through Detection and beta-acceleration Mechanism

IREC2012-PVE-254/O

61

256 Novel pyridinium iodide containing siloxane high performance electrolyte for dye-sensitized solar cell

IREC2012-PVE-256/P

62

265 An improved Maximum Power extraction control for a photovoltaic water pumping system

IREC2012-PVE-265/O

63

290 Effect of BSF on crystalline silicon solar cell using TCAD Silvaco Software

IREC2012-PVE-290/P

64

300 Predictive Power Control for Photovoltaic Grid Connected System

IREC2012-PVE-300/O

65

317 Application of Adaptative Fuzzy logic controller in Photovoltaic pumping System

IREC2012-PVE-317/P

66


327 Channel length effect on the temperature field in a Metal-Oxide-semiconductor Field Effect Transistor

IREC2012-PVE-327/P

67

330 PV-MEMS: PV Meteorological & Electrical Measurement System

IREC2012-PVE-330/P

68

331 Sliding mode observer and control of the solar photovoltaic water pumping systems without battery storage

IREC2012-PVE-331/O

69

341 A study of optical and structural properties of hydrogenated amorphous silicon films prepared at different conditions of pressure and time deposition

IREC2012-PVE-341/P

70

345 Modeling and simulation of a single phase photovoltaic system connected to the network under the islanding phenomenon

IREC2012-PVE-345/P

72

347 PV-C2ST: PV Characteristic Curves System Tracer IREC2012-PVE-347/O

73

354 Remote monitoring and performance analysis of stand-alone PV systems: the case study of a PV-Powered outdoor refrigerator

IREC2012-PVE-354/O

74

358 Vector Control based on fuzzy logic controller of Induction Motor for Photovoltaic Pumping System

IREC2012-PVE-358/O

75

378

Elaboration and Characterizations of Nanocomposites based on Poly(9-vinylcarbazole:Buckminsterfullerene for Photovoltaic Applications

IREC2012-PVE-378/P

76

381 Adaptive Fuzzy Controller Based MPPT for Photovoltaic systems

IREC2012-PVE-381/O

77

407 Modeling on radial solar cells under AM1.5G spectrum

IREC2012-PVE-407/O

78

408 Electrical study of doped PANi-TiO2 nanocomposites

IREC2012-PVE-408/P

79

416 Boron redistribution kinetics in strongly doped silicon thin bi-layers during thermal activation annealing

IREC2012-PVE-416/O

81

423 Phosphate ore washing by NA2EDTA for cadmium removal

IREC2012-PVE-423/P

82

84

Solar Thermal Energy 'STE' 85

86

49 Design and Test of Continuous Operation Modified Solar Still

IREC2012-STE-49/O

87


89 Theoretical study of a solar modular still under Algerian weather condition

IREC2012-STE-89/P

88

113 Numerical study of evaporation by mixed convection of a binary liquid film flowing down the wall of two vertical plates

IREC2012-STE-113/P

90

118 Thermal properties study of a solar water heater tank with a mantle exchanger

IREC2012-STE-118/O

91

126 The effects of volumetric flow rate and inclination angle on the performance of a solar thermal collector

IREC2012-STE-126/O

93

134 Performance evaluation of condensation-irrigation solar system under arid climate conditions

IREC2012-STE-134/O

94

154 Numerical and experimental investigation of thermosyphon solar water heater

IREC2012-STE-154/O

95

156 Thermal performance of an integrated collector storage solar water heater (ICSSWH) with phase change materials (PCM)

IREC2012-STE-156/O

96

185 Modeling study of vacuum membrane distillation under with coupling colar

IREC2012-STE-185/P

97

193 Enhancing the stepped solar still performance using internal reflectors

IREC2012-STE-193/O

99

196 Tomatoes drying in forced convection type solar dryer

IREC2012-STE-196/P

100

226 Experimental study for the performance of a solar distiller

IREC2012-STE-226/O

102

239 Study of heat transfer in an inclined triangular cavity filled with a Cu–water nanofluid

IREC2012-STE-239/P

103

252 Numerical study of a fixed bed drying at high-temperature of alumina AL2O3

IREC2012-STE-252/O

104

257 Analysis of heat and mass transfer in a co-courant flow membrane -based enthalpy exchanger

IREC2012-STE-257/O

105

271 Thermal study of mixed convection with viscous dissipation and pressure work

IREC2012-STE-271/P

106

282 Thermal performance study of a solar desalination unit

IREC2012-STE-282/P

107

297 Techno economic performances of a dry cooling solar tower power plant under Algerian climate

IREC2012-STE-297/O

108

306 Parametric studies on the thermal solar membrane distillation equipped with a helically coiled fibers

IREC2012-STE-306/O

110

309 Numerical study of transient double–diffusive natural convection in a salt–gradient solar pond

IREC2012-STE-309/O

111

329 Numerical study of mixed convection in tilted lid driven cavities at low reynolds numbers

IREC2012-STE-329/P

113


334 Comparison of different configurations to improve the liquid film evaporation in the vertical annulus

IREC2012-STE-334/P

114

342 Design of a simple solar still IREC2012-STE-342/O

115

348 Large eddy simulation of turbulent flow in Rayleigh-BÃ©nard configuration

IREC2012-STE-348/P

116

349 Numerical simulation of the flow and heat transfer around a rotating cylinder

IREC2012-STE-349/P

117

352 Numerical study of natural convection from rectangular and semi-circular cavity: effect of shape and angle of inclination

IREC2012-STE-352/P

118

356 Energetic optimization of flat plate solar collectors in transient behavior

IREC2012-STE-356/O

119

361 Numerical study of a Photovoltaic thermal (PV/T) collector

IREC2012-STE-361/O

120

364 Appraisal of the effect of solar passive techniques on the thermal performance of a glazed building in Tunisia

IREC2012-STE-364/O

121

368 Performance analysis of single stage LiBr/H2O and LiCl/ H2O solar absorption heat transformer

IREC2012-STE-368/O

122

370 Experimental and numerical investigation of a solar water heater with latent storage cavity

IREC2012-STE-370/O

123

371 Modeling and experiment of a solar air collector intended for the drying of leaves product

IREC2012-STE-371/P

124

374 Performance of an improved Trombe wall: An experimental study

IREC2012-STE-374/O

125

404 Numerical simulation of radiative heat transfer in non gray media using the CVFEM

IREC2012-STE-404/O

127

405 Design of a micro grooved receiver surface for a solar powered stirling engine generator

IREC2012-STE-405/O

128

130

Energy Management and Storage 'EMS'

131

132

69 Fuzzy energy management of an off-grid PV/Battery system

IREC2012-EMS-69/O

137


76 Dose rate calculation in a PMMA dosimeter IREC2012-EMS-76/P

138

80

Effect of inter-cooling on the performance of the solar energy assisted hybrid air conditioning system (SEAHACS) with one-rotor six-stage rotary desiccant cooling system

IREC2012-EMS-80/O

139

81

Numerical Compression Between the Performances of Solar Energy Assisted Hybrid Air Conditioning System (SEAHACS) for Using One-Rotor Two, Four, Six-Stage Rotary Desiccant Cooling System

IREC2012-EMS-81/O

140

86 Energy consumptions of lighting systems in the terminal buildings in turkey and energy-saving applications

IREC2012-EMS-86/O

141

88 Energy management opportunities for productivity enhancement in a medium scale manufacturing industry in lagos

IREC2012-EMS-88/O

142

110 Modeling of a gamma Stirling engine IREC2012-EMS-110/O

143

111 Investigation of the rutting performance of hot and warm asphaltic concretes: experimental and stochastic approaches

IREC2012-EMS-111/O

144

114 Micro hydroelectric power in Sicily: the energy production of early XIX sec. and the future opportunities

IREC2012-EMS-114/O

145

120 Performance testing of mobile phone battery IREC2012-EMS-120/O

146

125 A real time energy management for electrical vehicle using combination of rule-based and ECMS

IREC2012-EMS-125/O

147

145 Pressure-composition-isotherm behaviors of MgHx-graphene composites by reactive mechanical alloying

IREC2012-EMS-145/P

148

146 Materials life cycle assessments and evaluations of hydrogenation property on MgHx-BZY composites by reactive mechanical alloying

IREC2012-EMS-146/P

149

164 Energy saving design method of power transformer optimization by ant colony algorithm

IREC2012-EMS-164/P

151

167 Experimental study of gravity assisted heat pipe charged with methanol

IREC2012-EMS-167/O

152

173 Exergo-economic optimization of enhanced finned tube air-water heat exchanger

IREC2012-EMS-173/O

153

174 Application of evolutionary algorithm for triobjective optimization in traction chain of the electric vehicles

IREC2012-EMS-174/P

154


180 Energy storage on porous media using lattice boltzmann method

IREC2012-EMS-180/O

155

194 Economic and fiscal policy analysis on geothermal power plant in Indonesia

IREC2012-EMS-194/O

157

204 Vector control of an induction motor for photovoltaic pumping

IREC2012-EMS-204/O

158

223 solubility in supercritical carbon dioxide of hydroxybenzoic acid isomers: Correlation and prediction

IREC2012-EMS-223/O

159

240 Numerical simulation of heat and mass tranfer IREC2012-EMS-240/P

160

270 Energy savings potential from replacing traditional bulbs with energy saving bulbs in residential sector of Libya

IREC2012-EMS-270/O

161

277 Electric drive control: multi-level optimization efficiency

IREC2012-EMS-277/O

162

279 Competitiveness Trend of Renewable Energies: Tunisian Case

IREC2012-EMS-279/O

163

286 Energy storage using the phase change materials: Application to the thermal insulation

IREC2012-EMS-286/O

164

294 Storage Energy Management in Photovoltaic Systems using the Fuzzy logic Technique

IREC2012-EMS-294/O

165

301 How renewable energy will change electricity markets fundamentally

IREC2012-EMS-301/O

166

305 Effects of operating parameters on the performance of Single stage CO2 trans-critical refrigeration cycles.

IREC2012-EMS-305/O

167

311 Combustion of hythane diluted with CO2 IREC2012-EMS-311/O

168

325 Perspectives for alternative energy carriers based on renewables from technical and energetic point-of-view

IREC2012-EMS-325/O

169

336 Charge and discharge analysis of a lead acid battery used in solar PV systems

IREC2012-EMS-336/O

170

376 Design and Analysis of a High Frequency Dual Active Bridge DC-DC Converter for Super Capacitor Used in Electrical Vehicle

IREC2012-EMS-376/O

171

418 Control of hybrid sources for electrical train power

supply IREC2012-EMS-418/O

172

Biomass and Hydrogen Energy 'BHE' 173


174

35 Adsorption Kinetics of anionic dyes from aqueous solutions on activated Algerian kaolin "•DD3"• and bentonite

IREC2012-BHE-35/O

176

51 Maximizing the energy potential of palm kernel shell by pyrolytic conversion to biofuel

IREC2012-BHE-51/O

177

65 Phytoecology protected steppes of Stipa tenacissima after exclosure near Naama (western Algeria)

IREC2012-BHE-65/P

178

68 Experimental investigation of CO2 separation from lignite flue gases by Molten Carbonate Fuel Cell

IREC2012-BHE-68/O

179

72 Experimental study of oxytetracycline retention by adsorption by the peanut shells coated with the polyaniline

IREC2012-BHE-72/P

180

77 Comparison between the effect of acid and basic chemicals activation of cedar cone on the sorption of Rhodmaine B from aqueous solution

IREC2012-BHE-77/O

181

82 Gaseous products and particulate matter emissions of biomass residential boiler fired with spent coffee grounds pellets

IREC2012-BHE-82/O

182

150 The use of olive waste for agropellets production: Characterization study

IREC2012-BHE-150/O

183

155 Numerical study of surface waves generated by sudden movement at the sea bottom

IREC2012-BHE-155/O

184

165

Proton conducting hybrid membrane electrolytes based on Sulfonated poly(ether sulfone)s and Metallophthalocyanine contained poly(ether sulfone)

IREC2012-BHE-165/P

185

170 A PEM Fuel Cell Modeling : First Approach IREC2012-BHE-170/O

186

188 Combustion tests of date palm residues in a small pellets boiler for energy recovery

IREC2012-BHE-188/O

187

198 Preparation and N2, CO2 adsorption of activated carbon pellets derived from olives stones

IREC2012-BHE-198/O

188

212 Simultaneous biohydrogen production and wastewater treatment based on the selective enrichment of the fermentation ecosystem

IREC2012-BHE-212/P

190


215 An experimental study of combustion in spark ignition engine

IREC2012-BHE-215/P

191

221 Experimental investigation and combustion analysis of biogas with different compositions in dual fuel diesel engine

IREC2012-BHE-221/O

193

227 Environmental chemistry and mineralogy of particulate air matter at The phosphate mining basin of Gafsa

IREC2012-BHE-227/O

194

234 Modeling of heat and mass transfer in porous reactive media

IREC2012-BHE-234/P

196

236 Effect of Geometrical Parameters on the Transfer of Charges in the PEM fuel cell

IREC2012-BHE-236/O

197

244 Hydrogen permeability of Al2O3-CuO-ZnO/Ni composite membrane

IREC2012-BHE-244/P

198

245

Synthesis and properties of sulfonated poly(ether sulfone)s containing a mixture of cis and trans mesonaphthobifluorene moiety using bis(4-hydroxyphenyl)-1,2-diphenylethylene for PEMFC

IREC2012-BHE-245/P

199

260 Effects of PTFE variation of anode backing layer to use of high concentration methanol fuel in a direct methanol fuel cell

IREC2012-BHE-260/P

200

262 The effects of multi-layer electrode design in direct methanol fuel cells

IREC2012-BHE-262/P

201

263 Fuel Cell Emulator and high efficiency control IREC2012-BHE-263/O

202

267 Experimental study of biodegradability of dairy wastes in mesophilic conditions

IREC2012-BHE-267/P

203

268 Lattice Boltzmann simulation of two-phase flow in bipolar plat of PEM fuel cell

IREC2012-BHE-268/O

204

307 Effect of the flow variation on the tracer transport in a soil column for two porous media

IREC2012-BHE-307/O

205

308 Electrochemical model of external reforming solid oxide fuel cells

IREC2012-BHE-308/O

206

316 Single and multi-component adsorption of 2-nitrophenol and salicylic acid onto chemical olive stones activated carbon

IREC2012-BHE-316/O

207

333 Modelling of an offshore hydrogen production from wave energy

IREC2012-BHE-333/O

208

339 The electrical properties of sputtered GDC thin films on sapphire for solid oxide fuel cell

IREC2012-BHE-339/P

209


346 The effect of heat treatment on the catalytic properties of cobalt based electrocatalyts on carbon nanotubes prepared by sputtering

IREC2012-BHE-346/P

211

355 Study of inhibiting effect of NaCl on the biodegradability of dairy wastes

IREC2012-BHE-355/O

212

375 Effect of hydrogen addition on methane/air auto ignition under HCCI engine combustion mode

IREC2012-BHE-375/O

213

382 Chemistry and mineralogy studies of PM10 atmospheric aerosols in the Gulf of Gabès, South Tunisia

IREC2012-BHE-382/O

214

383 Numerical study of a fuel cell coupled to metal-hydrogen reactor

IREC2012-BHE-383/P

215

384 Utilization of waste Tunisian palm tree date as low-cost adsorbent for the removal of dyes from textile

IREC2012-BHE-384/O

216

393 Development of hybrid Photovoltaic-fuel cell system for stand-alone application

IREC2012-BHE-393/O

217

394 Electrodialysis performances and environmental issue

IREC2012-BHE-394/O

218

396 Production and characterization of biodiesel from allamanda cathertica oil

IREC2012-BHE-396/P

219

397 A novel method for improving the catalytic activity of carbon supported Co-B catalyst for hydrogen generation through hydrolysis of NaBH4

IREC2012-BHE-397/O

220

406 Numerical simulation of heat and mass transfer during biomass pyrolysis in a packed bed reactor

IREC2012-BHE-406/O

221

417 Study of optical and structural parameters of LPCVD silicon oxynitride layers for solar cells applications

IREC2012-BHE-417/P

223

224

Modelling, Simulation and Control 'MSC'

225

226

9 Improvement of the performances of the electronics components using MATLAB / SIMULINK

IREC2012-MSC-9/P

227

10 Computer Analysis Of The Inverter With Series-Parallel Resonnance Circuit Applied To Photovoltaic Energy

IREC2012-MSC-10/P

228

11 A transient study of coupled convection and radiation using a mesoscopic approach

IREC2012-MSC-11/O

229

67 Chaos and Bifurcation of DC-DC Buck Converter IREC2012-MSC-67/O

232


87 Sliding mode control of multi-cells inverter applied to an active power filter with unbalanced voltage

IREC2012-MSC-87/O

233

95 Identification of wind turbine blade defects using airborne acoustic measurement and residual matrix of principal component analysis

IREC2012-MSC-95/O

235

115 Analysis and performance of a switched reluctance generator for wind energy application

IREC2012-MSC-115/O

237

127 Smart Grid technology for better integration of renewable energy resources

IREC2012-MSC-127/O

238

128 Transient performance of stand-alone inductiongenerator

IREC2012-MSC-128/O

239

130 Multi-objective generation scheduling using genetic-based fuzzy mathematical programming technique

IREC2012-MSC-130/P

240

138 Thermosolutal natural convection and thermal radiation inside a porous enclosure

IREC2012-MSC-138/P

241

139 Study of entropy generation inside a porous enclosure

IREC2012-MSC-139/O

242

166 Combined Cycle for power generation and low temperature refrigeration using low temperature heat sources

IREC2012-MSC-166/P

243

176 3D study of heat and fluid flow of air filling containers partially heated from below

IREC2012-MSC-176/P

244

178 Aspect ratio effect on drying of saturated deformable porous media using the Lattice Boltzmann Method

IREC2012-MSC-178/O

245

183 Dual source heat pump: modeling and simulation on TRNSYS

IREC2012-MSC-183/P

246

201 Numerical simulation of turbulent two-phase free surface flows

IREC2012-MSC-201/O

247

209 Robust output voltage regulation and unity power factor with Sliding Mode Control

IREC2012-MSC-209/P

248

228 Modeling and control of a low pressure discharge lamp used for ultraviolet radiations water disinfection

IREC2012-MSC-228/O

250

241 Application of the Coordinated Voltage Control Technique to the Tunisian Distribution Network Using the Virtual Power Plant Approach

IREC2012-MSC-241/O

251

242 Automated Cleaning System for Street Light PV Solar Panel

IREC2012-MSC-242/P

252

246 Numerical Study of the Effect of Medium Capacity with Chemical Heterogeneity on the Reactive Dispersion in Porous Media

IREC'12-MSC-246/P

253

249 A simple tracking system to monitor solar receivers and PV panels

IREC2012-MSC-249/O

254


253 Improvement of Power System Transient Stability Using Resistive-Type Fault Current Limiters SFCL

IREC2012-MSC-253/O

255

255 Simulation tool for energetic analysis of mobile photovoltaic systems

IREC2012-MSC-255/O

256

259 Design and Implementation Two Axes Sun Steps-Tracking System

IREC2012-MSC-259/P

257

278 Speed sensor less using sliding mode observers of stator currents and rotor flux for induction motor

IREC2012-MSC-278/O

258

291 A Multi Agent Petri nets model based strategy for electric power management in microgrids

IREC2012-MSC-291/O

260

292 A second order modelling of a stably stratified turbulence submitted to a non vertical shear

IREC2012-MSC-292/P

261

293 Modeling of unsteady cavitating flow IREC2012-MSC-293/O

262

310 Numerical instabilities in a confined jet with double diffusion

IREC2012-MSC-310/P

264

312 Confined Jet with Double Diffusion IREC2012-MSC-312/P

265

324 Crossover from weak to strong localization in quasi-two-dimensional systems with diagonal disorder

IREC2012-MSC-324/P

267

326 Performance investigation of an activated carbon-CO2 based adsorption cooling cycle

IREC2012-MSC-326/O

268

359 A New PV cell Model Based on Multi Model Approach

IREC2012-MSC-359/O

270

360 Two Scenarios in MicroGrid to solve Management problem for Residential Application Using Genetic Algorithms

IREC2012-MSC-360/O

271

363 Numerical study of a desiccant cooling installation IREC2012-MSC-363/O

272

365 Modeling and supervision of energetic process : a double effect evaporator

IREC2012-MSC-365/O

273

385 Dumping effects of forced sloshing motion with submerged vertical baffles.

IREC2012-MSC-385/O

274

388 Experimental and numerical study of flow issued from a chimney around a cylindrical obstacle

IREC2012-MSC-388/O

275

392 Numerical and experimental study of a jet in crossflow

IREC2012-MSC-392/O

276

402 Simulation and control of flow injection in the microsystems

IREC2012-MSC-402/P

277


409 Performance evaluation of solar box oven with automatic tracking system

IREC2012-MSC-409/P

278


Wind and Hybrid Energy

‘WHE’

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-WHE-54/O

- 4-

Induction generator controlled by a modulated

hysteresis direct torque control (MHDTC) in a wind

conversion system

D.Rekiouaa R.Abdelli

a, T. Rekioua

a and A. Tounzi

b

aLaboratory LTII, University of Bejaia, (Algeria).

b Laboratory of Electrical Engineering and Electronics of Power of Lille, L2EP

(France).

[email protected]

Abstract

This paper describes a modulated hysteresis direct torque control (MHDTC) applied to an induction generator (IG) based wind conversion systems (WECs) connected to the electrical network. The strategy consists in controlling directly the electromagnetic torque by using a modulated hysteresis controller. The improvements obtained are principally a constant switching frequency in the inverter and and low THD in grid current. In order to verify the effectiveness of the proposed method, we make a comparison with classical direct torque control (DTC). The obtained simulation results using Matlab/Simulink with a variable wind profile show an adequate dynamic of the conversion wind system

Keywords: Modulated Hysteresis Direct Torque Control (MHDTC), Induction Generator

(IG), Direct Torque Control (DTC), Wind conversion system, Efficiency,

Power factor.

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-WHE-55/P

- 5-

Maximizing wind power based on double-fed

asynchronous generator by fuzzy logic

S. BELLARBI1, D. KOUSSA

1 A. MALEK

1, N.KASBADJI MERZOUK

2

1Center for Development of Renewable Energy, Bouzereah, Algiers.

2Solar Equipment Development Unit / EPSTt CDER, Algiers.

[email protected]

Abstract

This article has for objective the study by fuzzy logic simulation optimized by double-fed asynchronous generator (DFAG) with stator flow directed simile by MATLAB/SIMULINK. The system consists a horizontal wind turbine coupled with DFAG piloted through rotor by two three-phase static converters to PWM in double bridge, for maximized the power supplied with various wind speeds, we use da speed regulator classic, then a speed regulator fuzzy logic. At first, a modeling of the wind speed, the wind turbine. Afterward, a model of the double-fed asynchronous generator commanded by MPPT for two scenarios : with and without fuzzy logic.

Keywords: Wind speed, wind energy, PWM converter, double-fed asynchronous

generator, fuzzy controller, Simulation.


- 6-

Techno-economical study of hybrid power system

for refrigeration applications in the arid region in

Algeria

Maamar LAIDI(1,2)

, Salah HANINI2, Nachida KASBADJI MERZOUK

1,

Mohamed ABBES1

1 FTEER/FCER, Solar Equipment Development Unit (UDES) of Bou Ismail

Tipasa. 2 LMBPT, Dr. Yahia Fares University of Médéa.

[email protected]

Abstract

The The present work shows an experimental investigation of using a combination of solar and wind energy as hybrid system (HPS) for electrical generation under the Algerian Sahara area. The generated electricity has been utilized mainly for cooling and freezing (containers). The system has also integration with gasoline generator to have more reliable system. In the studied system is not linked with conventional energy and is not fixed in one region (military case in the Algerian borders GGF). The cooling load was considered as two cold containers (internal temperature is +2°C while the external temperature is 35°C) of 10 m3 each and one freezing room with the same volume (internal temperature is -20°C while the external temperature is 35°C). The important element is electricity load of average value 45 kWh/day for one barrack. To simulate the hybrid power system (HPS), measurements included the solar radiation intensity, the ambient temperature and the wind speed was collected from Adrar weather station for the year of 2010. Emissions and the renewable energy generation fraction (RF) of total energy consumption are calculated as the main environmental indicator. Costs including net present cost (NPC) and cost of energy (COE) are calculated for economic evaluation. It is found that, for Adrar climates, the optimum results of HPS show a 80% reduction of emissions. RF of the optimized system is 47 %. It is also found that the HPS has benefits of cost saving. In addition, through a set of sensitivity analysis, it is found that the wind speed has more effects on the environmental and economic performance of a HPS..

Keywords: Environment; Economy; Algerian Sahara Area; Hybrid Power System;

Refrigeration, HOMER


- 7-

Analyze Unsteady Flow 3D around a Blade Rotor of

Horizontal Axis Wind Turbine

Belkheir NOURA1, Ivan DOBREV

2, Rabah .DIZENE

3, abdelkader

ZARAAOUI1

1Centre universitaire de Khemis Miliana, Ain Defla, Algérie.

2Arts et Métiers Paris Tech, 151, Boulevard de l’Hôpital 75013 Paris, France.

3USTHB, PO Box 32 El Alia, Alger, Algérie.

[email protected]

Abstract

The prediction of the aerodynamic properties of the horizontal axis wind turbine is difficult. The interactions of the blade and the close wake with the flow can involve impulsive changes of efforts on part of thblades in rotation. Simulations of the unsteady incompressible flow around the blade in rotation in three dimensions are thus essential for the prediction of the aerodynamic efforts. This article presents an analysis of the unsteady flow around a blade of three-bladed wind turbine named Rutland 503. The approach DES (Detached Eddy Simulation) based on the Navier-Stokes equations with the model of turbulence SST and an approach of grid multi structured block is used in the modeling of the flow. The solutions are obtained by using the solver Fluent who uses the method of finites volumes. Simulations are made for speeds of moderate and strong wind. The results of simulations obtained are compared with the experimental data [1] obtained in Wind Tunnel Laboratory LMA Arts and Métiers Paris-Tech for a validation. The goal of these numerical simulations is to obtain information concerning the field speed around the blade in order to calculate its aerodynamic properties when the speed of the wind becomes strong. The estimate of the aerodynamic loads and a comprehension improved of the unsteady of the wind turbine environment will help effectively the engineers of wind turbine to conceive a rotor structure which increase life-time and improve the capture of energy under condition of strong wind.

Keywords: Unsteady Flow, 3D, DES, Horizontal Axis Wind Turbine, Blade of Rotor


- 8-

Lightning damage on the wind power generation

systems (study and simulation)

1*DIB Djalel,

2LABAR Hocine

1*Department of electrical engineering, Laboratory of electrical engineering

LABGET, University of Tebessa- 12002-Algeria. 2Department of electrical engineering, University of Annaba- 23000- Annaba

Algeria.

[email protected]

Abstract

Generally, lightning damage has mainly been to home appliances and telephones, Towers and power transmission and generation equipment mal functions and damage due to strikes on power lines. With the adoption of wind power generation equipment, however, lightning damage is also increasing in this area. Through his dimensional characteristics, the wind power system is more exposed in the nature compared to all others systems. Lightning damage is the single largest cause of unplanned downtime in wind turbines, and that downtime is responsible for the loss of countless megawatts of power generation. The wind turbines are important structures, since they can easily attract the wrath of storms hits heights close, they can also capture the most distant. The rotation of the blades may also trigger lightning and result in considerable increase in the number of strikes to a wind turbine unit. Since wind turbines are tall structures, the lightning currents that are injected by return strokes into the turbines will be affected by reflections at the top, at the bottom, and at the junction of the blades with the static base of the turbine. We present our contribution in this paper to study lightning strokes and their effects on the wind turbines with the aim to enrich the work and to suggest more effective means of protection against lightning.

Keywords: wind turbine, lightning, protection, blade, current return stroke, carbon

reinforced plastics


- 9-

The digital energy management of a stand-alone

hybrid system (photovoltaic & wind)

M. SEDDIK, S. ZOUGGAR, M. OUKILI, T. OUCHBEL, A. AZIZ, M.L

ELHAFYENI

Higher Institute of Technology EEML - BP. 473 Hay El Qods - 60000 - Oujda,

Morocco.

[email protected]

Abstract

In this paper, a hybrid energy system composed of photovoltaic panels (PV), wind and storage battery is proposed for stand alone continuous load. Three DC-DC converters (a boost, tow Buck/boost shunt) are used with the feedback voltage control for tracking the maximum power point of PV and regulate the voltage of bus DC at a fixed value √2 * 220 . The main objective is assured a continuous supply to the load demand (1.5 kW), while supervising the output power from renewable energy system and the state of charge/discharge of storage battery. In order to make function the complete system under the optimal conditions we propose a digital control energy management simple and cost-effective ( based on electronic switches and dump load). The proposed system is attractive because of its simplicity and control ease. The results prove that the system can ensure the high quality power to the load, even if the sun and wind are unavailable permanently. A complete description of the energy management strategy and control systems proposed in this document. Orcad Pspice simulation results have shown the availability and reliability of the proposed hybrid system.

Keywords: hybrid System, photovoltaic System, Wind system, DC-DC Converter, Energy

management


- 10-

Power Maximization of an Asynchronous Wind

Turbine with a Variable Speed Feeding a

Centrifugal Pump

T.OUCHBEL1, S.ZOUGGAR

1, M.EL HAFYANI

2 ,M. A.AZIZ

1 , M.SEDDIK

1,

M.OUKILI1 and F.Z. KADDA

1

1 University Mohammed 1

er, School of Technology Oujda

Laboratory of Electrical Engineering and Maintenance (LEEM) BP, 473, 60000

Morocco. 2 University Mohammed 1, National School of Applied Sciences Oujda.

[email protected]

Abstract

This article focuses on the study of a pumping system compound with a wind turbine, a self-excited induction generator (SEIG), an induction motor (IM), and a centrifugal pump (CP). This system is supposed to ensure the water pumping in optimum conditions regardless of the wind speed.

As a first step, we performed a study in steady state and practical testing to determine the control law: power as a function of initiating capability of the SEIG and the wind speed. In addition, a dynamic study of the system is examined.

Second, we have proposed an MPPT algorithm based on a static converter SVC, Whose aim is to achieve a maximum energy flow. Different experimental and simulated results allow evaluating the system performance and the algorithm proposed.

Keywords: Self-Excited Induction Generator, Centrifugal Pump, Induction Motor, MPPT,

Static Converter SVC


- 12-

Steady and unsteady combined numerical methods

applied in HAWT dynamic stall simulation

Noura BELKHEIR1, DIZENE Rabah

2 and KHELLADI Soufiane

3

1Centre Universitaire de Khemis Miliana.

2LMA, Université des Sciences & de la Technologie Houari Boumediene.

3ENSAM Arts & Métiers, Paris-Tech France.

[email protected]

Abstract

The study of a HAWT turbine subject to operating conditions in the presence of wind is very complex as it is subject to instantaneous speed and wind direction variation which can drive inevitably the turbine blades into dynamic stall. The intensity of this phenomenon led to a sudden drop in lift coefficient and hence the degradation of its aerodynamic performance. This work presents two-dimensional numerical simulation of the instantaneous change of wind direction with respect to the turbine blade and a comparison with experimental data available in the literature. For simulations that best reproduce these variations in flow direction (wind) we examined the effect of the incidence angle variation of an oscillating -S809 profile. Considering that the drop came from the sudden increase of turbulent separation at the trailing edge, URANS approach is used to predict the stall, using the SST k- and standard k-ε turbulence models. The FLUENT software was used for the numerical solution of the problem. The numerical results were compared with the experimental data reported by Reuss Ramsay et al. (1995). The results show the importance of taking into account the behaviour of the unsteady flow in the wind farm to obtain an accurate estimate of the wind turbine aerodynamic load.

Keywords: Wind Energy, Horizontal axis wind turbine rotor, wind tunnel, four dynamic

stall, wind simulation.


- 13-

Control of two-dimensional incompressible laminar

boundary layer by blowing

NAHOUI Azzedine, BAHI Lakhder

Université,Mentouri, Constantine, Labo Energétique, Algérie.

[email protected]

Abstract

A laminar, two-dimensional, incompressible boundary layer around a profile and its control using blowing is studied numerically. The study is based on the Prandtl boundary layer model using the finite differences method and the Crank-Nicolson scheme. The study concerns the flat plate case, NACA 661012 and the NACA 0012 profile. The velocity distribution, the boundary layer thickness and the friction coefficient distribution are determined and presented with and without control. The application of the control technic, has demonstrated its positif effect on the transition point and the friction coefficient. The control procedure is compared for different porosity lengths, blowing speeds and blowing angles.

Keywords: boundary layer, laminar, two-dimensional, incompressible profile, control,

blowing, friction coefficient.


- 14-

Realization of wind emulator and Control of a

Wind Turbine Connected to the Grid by Using

PMSG

A. DAHBI, M. HACHEMI

Department of Electrical Engineering, Setif University.

[email protected]

Abstract

This paper describes the operation and control of a variable-speed wind generator using the permanent magnet synchronous generator (PMSG), starting by realization of the wind profile using Dspace to impose the corresponding speed on the DC motor to be as a wind emulator. This generator is connected to the grid by means of two fully controlled converters, rectifier and an inverter, both are controlled by pulse width-modulation (PWM), between them an intermediate DC circuit. The main objectives in this paper are: extracting maximum power from wind, and feeding the grid by high power quality of electrical energy; to achieve these, we applied the strategies of maximum power point tracking (MPPT) with speed controller. To deliver this power to the grid, the DC bus voltage is controlled by inverter in a way to deliver only the active power into the grid, thus we have unit power factor; then we affected variations in resistor, DC voltage link and field This paper shows the simulation of the complete system using Matlab Simulink to see its dynamic performance.

Keywords: Permanent-magnet synchronous generator (PMSG), Maximum power point

tracking (MPPT) control, Pulse wave modulation (PWM), modelling.


- 15-

Optimal allocation and design of grid connected

hybrid systems

Amany M. El-ZONKOLY

Arab Academy for Science & Technology, Faculty of Eng. & Tech, Alexandria,

Egypt.

[email protected]

Abstract

This paper presents an artificial bee colony (ABC) based algorithm to optimally allocate, design and schedule hybrid photovoltaic-diesel distributed generation in distribution systems. The objective of the proposed algorithm is to minimize the overall cost of the hybrid photovoltaic-diesel systems (HPVDS). The algorithm considers also the minimization of the distribution system power loss, the amount of un-served load and the imported power from the transmission grid.

Meanwhile, the algorithm aims to maximize the excess generated power by the

HPVDS that may be injected into the distribution network. These objectives are to be achieved while satisfying the operational constraints of the system. The proposed algorithm is applied to two test systems to validate its effectiveness.

Keywords: Hybrid photovoltaic-diesel systems (HPVDS), Artificial bee colony (ABC),

Distributed generation (DG), Load shedding


- 16-

Using a DFIG based Wind Turbine for Grid Current

Harmonics Filtering

M. KESRAOUI1, A. MEZIANE

2 and A. BOULEZAZ

2

1Laboratoire d’Automatique Appliquée, Université M’Hamed Bougara,

BOUMERDES. 2IGEE, Université M’hamed Bougara BOUMERDES.

[email protected]

Abstract

In this paper a variable speed doubly fed induction generator (DFIG) based wind energy conversion system (WECS) is employed for simultaneous power generation and grid harmonic current filtering. WECS active and reactive powers are controlled using vector control strategy. An improved harmonic isolator in the time domain, based on a new high selective signal detector has been used. The compensation technique of the whole harmonic components of the grid current is chosen. The rotor side converter (RSC) control structure has been modified in order to include the filtering task. Simulation results for a 3MW WECS with DFIG showed that in addition to power generation, grid current harmonics filtering action is achieved and a decrease by 4% of the total harmonic distortion is obtained.

Keywords: DFIG, Wind Power system, power generation, Harmonics Filtering, High

Selectivity Filter


- 17-

The performance of the H-Savonius combine

machine

Prof. Ali Mohamed ELMABROK, Dr Entesar.H.BETELMEL

Department of Aeronautical Engineering, Mechanical Engineering,Tripoli

University.

Faculty of Engineering P.O Box. 13154 Tripoli-Libya.

[email protected]

Abstract

Referring to ref [1], a new analytical method has been developed to predict the performance of Savonius rotors. The results of this method show an excellent agreement with the experimental results. This work is an extension to the research described in reference [1]. The majority of performance results of the H-Savonieus combined machine have been obtained experimentally, and none of the researches have studied theoretically the performance of such machine. In this paper we applied this new method to predict the performance of the combined machine. The performance of the H rotor is determined using the multiple stream tube theory see ref [2,3], while the performance of the Savonius rotors are predicted using the new analytical method as described in ref [1]. The two analytical methods are joined together to predict the performance of a combined machine. In this paper a H turbine (three bladed rotor of radius, R = 0.375m, and height, H= 0.75m) is combined with three different Savonius models (semi-circle, b/c = 0.0, b/c = 0.25, and Bach model), the general dimensions are shown in table 1. Experimental work on H rotor combined with the previous three Savonius models was undertaken. The theoretical results of the combined machine have been compared with the experimental results. The comparison shows a very good agreement.

Keywords: Combined machine, rotor, windmill, blades, vertical axis turbine, H rotor


- 18-

Influence of Rated Wind Speed on the Energy Yield

at a Site

Ibrahim M. RACHED , Mostafa H.S.ABOBAKER

Aeronautical Department- Tripoli University, Aeronautical Department-

Azawia University.

[email protected]

Abstract

It is well established that wind energy yield at a given site depends primarily on both the wind speed pattern there and the power curve of the wind turbine being used. A major characteristic of such a curve is the rated wind speed Vr the selection of which is considered to be an important input parameter for wind turbine design. Based on actual wind speed data collected at Misurata (Libya) and wind turbine power curves deduced from realistic representation of wind rotor power output characteristics, results of this study indicate that the above mentioned yield could be maximized for a value of Vr of about 11 meters per second. The results also show that the ratio of energy yield to installed energy, better known as capacity factor, continuously decreases with increasing rated wind speed.

Keywords: rated wind speed, wind turbine, wind rotor, wind energy, capacity factor.


- 19-

Wind farm power forecasting

Nabiha HAOUAS1, Pierre R. BERTRAND

2

1Laboratoire de Mathématiques, UMR CNRS 6620 and Université

Clermont-Ferrand 2 , France and Computational Mathematics

Laboratory,Monastir. 2Laboratoire de Mathématiques, UMR CNRS 6620 and UniversitéClermont-

Ferrand 2, France.

[email protected]

Abstract

Forecasting annual wind power production is useful for energy industry. Until recently, attention has been only paid to the forecasting of mean annual wind power energy and statistical uncertainties on this forecasting. Recently Bensoussan et al. (2012) have pointed that annual wind power produced by one wind turbine is a Gaussian random variable under a reasonable set of conditions. Next, they derive both mean, and quantiles of annual wind power produced by one wind turbine. The novelty in this paper is to develop this result to estimate the annual wind farm power production. Moreover, we study the relationship between the power outputs for each turbine in the farm to avoid the e ect of interaction between it.

Keywords: Wind speed, Wind direction, Power wind farm, Annual energyproduction,

Forecasting.


- 20-

Wind Turbine Powers Control Using Fuzzy Logic

Controllers

Azzeddine DEKHANE, Abdallah ABDERREZAK

Department of Electrical Engineering Badji Mokhtar-Annaba University P.O.

Box 12, 23000 Annaba, Algeria.

[email protected]

Abstract

Wind turbines are controlled to provide constant active and reactive power during a certain period. We present in this paper, three types of active and reactive power separate control for horizontal axis wind turbine in order to compare their performance: the direct method with a PI and a Fuzzy Logic controllers, and also the indirect method control with powers feedback. We present the model of the system to be controlled; the simulations results realized under Matlab / Simulink software are mpared and analyzed.

Keywords: Wind Turbine, modeling, control, decoupling


- 22-

Relationship between open angle and aerodynamic

performances of a DiffuserAugmented Wind

Turbine‘DAWT’

Rym CHAKER1, Mouldi KARDOUS

1, Fethi ALOUI

1, Sassi BEN NASRALAH

2

1Research and Technology Center of Energy (CRTEn)–Borj Cedria Technopark

BP. 95, Hammam-Lif 2050, Tunisia . 2National Engineering School of Monastir –Avenue Ibn El Jazzar, 5019

Monastir, Tunisia.

[email protected]

Abstract

The energy generated by a wind turbine is proportional to its swept area and to the third power of the wind speed. Therefore, expanding the swept area and/or increasing the wind speed can significantly increase the output power. Flanged diffuser augmenting small wind turbine is one of the most indicated tool for increasing wind power output.

The open of the frustum-shaped is among the geometric characteristics that

effectively affects diffuser aerodynamic performances. Results obtained from numerical simulations and experiments show that wind speed in the inlet section of an empty diffuser increases linearly with the open angle ranged from 2 to 10°, it reaches a maximum for 10° (numerical simulation) and 7°(experiment measurements) and then decreases. When a turbine is mounted within the diffuser beyond the values of 10°, the open angle seems to be without significant effect on increasing wind velocity.

Keywords: Flanged Diffuser, Wind energy, Open angle, Simulations, Wind tunnel

experiments


- 23-

Realization and control of a wind turbineconnected

to the grid by using PMSG

Abdeldjalil DAHBI1, Mabrouk HACHEMI

2

1Department of Electrical Engineering, Setif University, Automatic Laboratory

of Setif (LAS), 19000Setif, Algeria. 2Department of Electrical Engineering, Automatic Laboratory of Setif (LAS),

19000Setif, Algeria.

[email protected]

Abstract

This paper studies the control of a variablespeed wind turbine for a direct driven generator using the permanent magnet synchronous generator (PMSG). The wind profile is realized by using Dspace to impose the corresponding speed on the DC motor. This wind turbine is connected to the grid by means of a fully controlled frequency converters, which consist of a pulse width-modulation (PWM) rectifier connected to an inverter by an intermediate DC circuit. This paper has two main objectives, the first, is extracting and exploiting the maximum power from wind, the second is feeding the grid by high-power and good quality of electrical energy; to achieve that, we applied the strategies of maximum power point tracking (MPPT) with speed controller which allows the PMSG to operate at an optimal speed. The inverter is used for delivering power to the grid, controlled by (PWM) in a way to deliver only the active power into the grid, thus we have unit power factor. DC-link voltage is also controlled by the inverter. This paper shows the dynamic performances of the complete system by its simulation using Matlab Simulink.

Keywords: Permanent-magnet synchronous generator(PMSG), Maximum power point

tracking (MPPT) control,Pulse Wave Modulation (PWM), modelling.


- 24-

Power Control of a Wind generator connected to

the network in front of Strong winds

Hakim BEKKA1, Saci TARAFT

1, Djamila REKIOUA

2, Seddik BACHA

3

1 Electrical engineering Department, A.Mira University, Bejaïa, Algeria .

2 L.T.I.I Laboratory, University of Bejaia ; Algeria.

3G2elab, INP Grenoble (France).

[email protected]

Abstract

The aim through this paper is to control the power of the wind turbine in strong winds, consequently the protection of the wind generator system. The latter is composed of a three-bladed turbine, a mechanism of mechanical orientation of blades, and a double-fed induction generator (DFIG), controlled by the variation of quantities rotor , the rotor part is connected to the infinite network of 690 Volts 50 Hertz through a cascade (rectifier, filter, inverter). The magnitudes are controlled by a field oriented control (FOC). For wind speeds of which the wind power is lower than the acceptable one, we get the optimal partial power back while applying the MPPT algorithm. For wind speeds of which the developed power exceeds the acceptable standard of that nominal, we limit the power produced by action of the mechanical system which makes revolve the blades of a necessary mechanical angle to limit the rotation speed of the turbine, corresponding to the power of instruction.

Keywords: double-fed induction machine (DFIG), variable speed wind turbine, field

oriented control (FOC).


- 25-

A fuzzy controlled scheme for hybrid photovoltaic-

diesel pumping system

Taoufik MHAMDI1, Noureddine HIDOURI

2, Sihem ELHELALI

3 ,

Lassâad SBITA4

1Higher Institute of Technological Studies of Kasserine, Department of

Electrical Engineering, Kasserine University, Feriana Street, Tunisia. 2Preparatory Engineering Institute of Gafsa, Department of Preparatory

Technological Engineering studies, Campus Universitaire Sidi Ahmed Zarrouk

- 2112 Gafsa, Tunisia, 3 InstitutSupérieur des Sciences Appliquéeset de Technologie de Kairouan

4 National Engineering School of Gabes, Department of Electrical and Control

engineering, Zrig, Gabes 6029, Tunisia.

[email protected]

Abstract

In this work the steady-state and the dynamic performance of a permanent magnet DC motor coupled to centrifugal pump CP supplied from Photovoltaic source (PV) through intermediate buck converter is developed ,studied and analysed. Simulations on a diesel engine driven centrifugal pump are presented .Other network components buck converter ,photovoltaic panels are implemented, modelled and simulated using Matlab/Simulink. The speed of the diesel engine is regulated by adjusting the fuel flux. The DC voltage produced by photovoltaic panel is maintained constant equal to the nominal PMDCM votage with a fuzzy logic controller .

Keywords: Diesel-engine, pump, supervisor, fuzzy controller, Photovoltaic.


- 26-

Modeling and control of brushless doubly-fed

induction generators in wind energy applications

MAHBOUB Mohamed Abd el basset, RAJEAI Hammoud

Department of Electrical Engineering, Automatic Laboratory University of

Setif, Algeria.

[email protected]

Abstract

In this paper Brushless doubly fed induction generators (BDFIGs) show commercial promise for wind power generation due to their lower capital and operational costs and higher reliability as compared with doubly fed induction generators (DFIG).This paper presents a vector-control scheme for a BDFIG operating as a variable speed generator. The proposed vector controller is developed on the power-winding stator-flux frame and can be used to control both the active and the reactive power. The machine model and the control system are developed in MATLAB. The test results show that the proposed controller has good dynamic performance when changes in active and reactive power are applied.

Keywords: Brushless doubly fed induction generator (BDFIG), Modelling, vector control

(VC).


- 27-

Direct torque control of grid connected doubly fed

induction generator for the wind energy conversion

S.TAMALOUZT1, T. REKIOUA

1, R. ABDESSEMED

2 and K. IDJDARENE

1

1 Laboratoire de Technologie Industrielle et de l'Information (LTII), Department

of Electrical Engineering, FT,University of Bejaia, Bejaia 06000, Algeria. 2 Department of Electrical Engineering, University of Batna, Batna 05000,

Algeria.

[email protected]

Abstract

This paper presents direct torque control of doubly fed induction generator (DFIG) driven by a wind turbine. In the proposed topology, the wind turbine is variable speed, allowing optimal energy capture from the wind. The electrical torque of the wind system generator is regulated to maximize the energy capture of the wind turbine. Based on the application of the standard switching table for an operation in the 4 quadrants to control the rotor flux and the electromagnetic torque of the doubly fed induction generator operated in twoquadrant. The control is tested and validated through simulations. The obtained results are presented and discussed.

Keywords: Doubly fed induction generator, Direct torque control, Wind power.


- 28-

A LOLP-based method to evaluate the contribution

of wind generation to power system adequacy

Esteban GIL, Ignacio ARAVENA

Universidad Técnica Federico Santa María.

[email protected]

Abstract

This paper studies the adequacy of the system (as measured by the Loss of Load Probability, LOLP) in terms of its total demand, and presents a LOLP-based method for estimating the capacity value of wind power generators grounded on reliability considerations. The application of the method to the Chilean Northern Interconnected System (SING) is discussed. LOLP versus demand curves for the SING are obtained by using repeated market simulations in a Monte Carlo scheme that accounts for both forced enerator outages and the wind resource uncertainty. A comparison of the capacity value for two different types of wind farms is performed using the proposed method, and the results are compared with the method currently used in Chile. The LOLP-based method proposed in the paper captures the contribution of the intermittent generation resources to power systemadequacy more accurately than the method currently employed in the SING.

Keywords: wind power, optimization, power system adequacy, capacity value, power

system modeling


- 29-

Wake structure of a horizontal-axis wind turbine

A.W. DAHMOUNI1, M.M. OUESLATI

1, M. BEN SALAH

2, S. BEN

NASRALLAH3

1 Laboratoire de Maîtrise de l'Energie Eolienne et de Valorisation Energétique

des Déchets, Centre de Recherche et des Technologies de l’Energie, Technopôle

de Borj-Cedria, BP 95 Hammam Lif 2050, Tunisia. 2 Laboratoire des Procédés Thermiques, Centre de Recherche et des

Technologies de l’Energie, Technopôle de Borj-Cedria, BP 95 Hammam Lif

2050, Tunisia. 3 Laboratoire d’Etudes des Systèmes Thermiques et Energétiques, Ecole

Nationale d’Ingénieurs de Monastir, avenue Ibn El Jazzar 5019, Monastir,

Tunisia.

[email protected]

Abstract

The rotor aerodynamics of a horizontal axis wind turbine consists of strongly coupled blade and wake aerodynamics. Therefore, for accurate prediction of performances and loads, it is imperative to develop and essentially to validate adequate numerical codes. So, experiments in controlled conditions, hence in wind tunnels, seem to be crucial to reduce their uncertainties. This paper presents an investigation on the near wake dynamics on lower wind speeds. Results of wind-tunnel measurements show clearly the existence of three helical sheets shedding from turbine blades downstream of the rotor and highlighted the great influence of the tip and root vortex in the structure of the near wake.

Keywords: wind turbine, near wake, tip vortices, root vortices, helical sheets


- 30-

Thermo-economic modeling of renewable energy

systems. Case study for wind farm

Mohamed Habib SELLAM

Unity of Research Thermal Radiation, Department of Physics, Faculty of

Science Tunis, University Elmanar.

[email protected]

Abstract

In this paper we have developed a model to optimise the thermo economic performance of the renwebale energy systems functioning . Applications for the eolian system and wind firm in the case of Tunisia will be detailed. As begining we have reminded the basic equations to conceptualise and to size the system. So we can estimate the direct costs of every system and to evaluate later the investment impact. The thermal transfert inside and the energy produced were formulated. Also we have considered in our calculus the environomic in order to quantify the indirect cost when valorising the renwable energy. Finally a global thermo-economic formulations were provided and results for the wind firms in tunisia were signaled.

Keywords: Investment, wind energy, thermoeconomic, environmental effect, cost


- 31-

Sensorless decoupled power control scheme of grid

connected variable speed wind turbine generator

based on modifiedPhase Locked Loop‘MPLL’

F. AKEL1,3

, M. LAOUR1, T. GHENNAM

2, EM. BERKOUK

3

1 Unité de Développement des Equipements Solaires (UDES), route Nationale

N°11, BP 386, Bou-Ismail, Tipaza, Algérie. 2 Laboratoire d’Electronique de Puissance (LEP), Ecole Militaire Polytechnique

d'Alger, BP 17, Bordj EL Bahri, Alger, Algérie. 3 Laboratoirede Commande des Processus (LCP), Ecole Nationale

Polytechnique d'Alger, BP 182, 10 avenue Hassen Badi, 16200 el Harrach,

Algérie

[email protected]

Abstract

The objective of this paper is to analyise a vector control of a grid connected variable speed wind turbine based on Doubly Fed Induction Generator (DFIG), that does not rely on mechanical sensors. This algorithm is based on a modified phase locked loop (PLL). With the measured stator voltages, stator and rotor currents, the proposed algorithm can directly obtain the rotor position and speed via simple arithmetic operation. The speed is estimated independently of machine parameters, which results in a significant improvement in speed control robustness against machine parameter variations. In addition, the algorithm avoids using differentiation, which significantly improves its immunity to noise and does not require the measurement of the rotor voltages.

Keywords: Wind turbine; DFIG; sensorless vector control; modified PLL, multilevel

inverter


- 32-

Analysis of Three Phase Matrix converter fed

inductive load for different output frequency

Aziz BOUKADOUM 1

, Tahar BAHI 2

, Abla BOUGUERNE 3

, Youcef SOUFI 4

,

Salima Lekhchine 2

1 Department of Electrical Engineering, University of Tebessa, Algeria.

2 Department of Electrical Engineering, University of Annaba, Algeria.

3 Department of Electrical Engineering, University of Constantine, Algeria .

4 Department of Electrical Engineer

[email protected]

Abstract

This paper present the AC-AC conversion of electrical energy based on a matrix converter, the matrix converter fed RL linear load under distorted input voltage conditions. to improve the quality of the three phase output currents of matrix converter, The performance of the matrix converter has been tested for different values of the output frequency.. Venturini optimum method and PWM technique control was proposed. The results of simulations obtained will be presented and interpreted.

Keywords: Matrix converter, disturbed input voltage conditions, output frequency , output

currents quality.


- 33-

Performance improvement of matrix converters

under disturbed input voltage conditions

Youcef SOUFI 1, Aziz BOUKADOUM

2, Tahar BAHI

3, Abla BOUGUERNE

4



3 Department of Electrical Engineering, University of Annaba, Algeria.

4 Department of Electrical Engineering,University of Constantine, Algeria.

[email protected]

Abstract

This paper presents a alternative conversion of electrical energy based on a matrix converter feeding three phase RL linear load. We aim to improve the waveforms sinusoidal output currents of matrix converter, under distorted input voltage conditions, the Venturini optimum method and PWM technique control was proposed. finally a special attention is given to the stability and to reduce the harmonic pollution in whole system. The results of simulations obtained will be presented and interpreted.

Keywords: Matrix converter, Venturini method, distorted input voltage conditions, ac-ac

converter.


- 34-

Backpropagation algorithm for diagnosis of

induction machine faults

Abla BOUGUERNE 1, Abdesselam LEBAROUD

2, Aziz BOUKADOUM

3

1 Laboratory LGEC, Department of Electrical Engineering, University of

Constantine, Algeria. 2 Laboratory LGEC Constantine, Department of Electrical Engineering,

University of Skikda, Algeria. 3 Department of Electrical Engineering, University of Tebessa,Algeria.

[email protected]

Abstract

This paper presents a diagnosis method based on classification of the current waveforms by neural networks. The diagnostic method is performed on three types of faults: bearing faults, stator faults and broken bars. The flexibility of this method allows an accurate classification independent from the level of load. This method is validated on a 5.5-kW induction motor test bench.

Keywords: Backpropagation algorithm, Diagnosis, Time-frequency, Classification, neural

network.


- 36-

Evaluation of wind power production prospective at

Baburband, Sindh Pakistan

Shahnawaz Farhan Khahro1, a, Kavita Tabbassum

2,

Amir Mahmood Soomro1, 3

, Lei Dong1, Xiaozhong Liao

1

1School of Automation, Beijing Institute of Technology, Beijing, 100081, P.R.

China. 2Information Technology Center (ITC) SAU Tandojam, Sindh Pakistan.

3Mehran University of Engineering & Technology Jamshoro, Sindh Pakistan.

[email protected]

Abstract

Pakistan is currently experiencing an acute shortage of energy and urgently needs new sources of affordable energy that could alleviate the misery of the energy starved masses. At present the government is increasing not only the conventional energy sources like hydel and thermal but also focusing on the immense potential of renewable energy sources like; Solar, Wind, Biogas, Waste-to-energy etc… The recent economic crisis worldwide, global warming and climate change have also emphasized the need for utilizing economic feasible energy sources having lowest carbon emissions. Wind energy, with its sustainability and low environmental impact, is highly prominent. The aim of this paper is to explore the wind power production prospective of one of the site in south region of Pakistan. Wind speed data for the period of one year is measured. Wind power densities and frequency distributions of wind speed at four different altitudes alongwith estimated wind power expected to be generated through commercial wind turbines is calculated. The yearly mean wind speed of the considered site is 6.712 m/s and has power density of 310 W/m2 at 80m height with high power density during April to August (highest in May with wind speed 9.595 m/s and power density 732 W/m2). Economic evaluation, to exemplify feasibility of installing wind turbines, is also done. The estimated cost of per kWh of electricity from wind is calculated as 0.0263 US$/kWh. Thus the candidate site is recommended suitable for some small stand-alone systems as well as for wind farm.

Keywords: Wind energy; power density function; Weibull distribution; frequency

distribution; wind rose


- 37-

Photovoltaic Energy

‘PVE’

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-PVE-24/O

- 39-

Growth Mechanism and Optical Properties of Zinc

Oxide Thin Film

S .Abdullahi1, M.Momoh

1, K. U. Isah

2

1Department of Physics, Usmanu Danfodiyo University Sokoto, Nigeria,

2Federal University of Technology Minna, Nigeria.

[email protected]

Abstract

Zinc Oxide(ZnO) thin films were successfully deposited on glass substrate by radio frequency (rf)sputtering technique. One set of the samples was annealed in open air at temperatures of 423 K, 573 K and 723 K for one hour while another set of samples was annealed under nitrogen atmosphere for the same duration of time and temperature as the other set. A growth mechanism for thin film growth by RF sputtering has been presented. The films were also characterized to assess their optical properties. The ZnO thin films showed good transmittance, low reflectance and good absorbance in the visible region. The energy band gap (Eg) obtained is in the range of (3.15-3.28eV) which is good for window layer of a solar cell. Other optical constants evaluated include refractive index and the extinction coefficient.

Keywords: RF sputtering, ZnO thin film, annealing


- 40-

Electrical and structural properties of radio

frequency (RF) sputtered ZnO thin film at low

substrate temperature.

M. Momoh1,S. Abdullahi

1,K.U.Isah

2

1 Department of Physics Usmanu Danfodiyo University Sokoto, Nigeria.

2Department of physics,Federal University of technology Minna,Nigeria.

[email protected]

Abstract

Transparent conducting Zinc Oxide (ZnO) thin films with an average thickness of 130nm were deposited on glass substrates at substrate temperature of 1000C by RF sputtering and annealed in nitrogen atmosphere at 423 K, 573 K and 723 K for 60 minutes. The electrical and structural properties of the films were investigated using four-point probe and scanning electron microscopy (SEM).The as-grown sample was found to have a resistivity of 11.0×10-4Ω.cm,while that of the annealed samples lies between 6.0×10-4Ω.cm-3.5×10-4Ω.cm. The XRD analysis of the annealed films shows that they are crystalline with preferential orientation of (002) plane. Other data analyzed from the samples includes the grain size (1.5059-1.8898), strain (1.77-0.11 %), residual stress (4.13-0.26 Gpa) and the dislocation density (0.4409-0.2800).

Keywords: ZnO, electrical resistance, RF-magnetron sputtering, XRD

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-PVE-52/P

- 42-

The effect of thickness on optical band gap and N-

type conductivity of CuInS2 thin films annealed in

air atmosphere

M. Ben RABEH, M. A. FODHA and M. KANZARI

Laboratoire de Photovoltaïque et Matériaux Semi-conducteurs ENIT BP 37,

Le Belvédère 1002-Tunis, Tunisie.

[email protected]

Abstract

Structural, electrical and optical properties of CuInS2 thin films of various thicknesses, grown on heated glass substrates at 100°C by thermal evaporation method were studied. These films were annealed in air atmosphere at temperature of 200°C. The thickness of the CIS films was varied from 436 to 80 nm. It was found that the structural properties, FWHM and grain size degraded with decreasing its thickness. However, with decreasing the film thickness from 436 to 80 nm, the optical band gap Eg first decreased, and then increased from 1.46 to 2.35 eV. Hot probe method showed that all the annealed CuInS2 samples exhibit n-type conductivity with low resistivity values in the range 3.60 to 0.08 kΩ.m. We suggests that the band gap energy of CuInS2 thin films can be controlled by varying the thickness of layer and n-type conductivity can be obtained after annealing in air atmosphere.

Keywords: CuInS2, Thin films, annealing, film thickness, Characterization


- 45-

The efficiency and economic of photovoltaic panel

as shading devices

Mustafa AHMIDA

Higher Institute of Refrigeration & Air Conditioning, Sukna- Libya.

[email protected]

Abstract

The efficiency and economic of photovoltaic panel as a shading devices has been calculated. This study has been conducted for several cities in Malaysia. The long term performance parameters such as monthly solar radiation data have been predicted using the local meteorological data. The highest solar radiation on horizontal surface happens on March, and in the slope surface also happens on March, with β=10. An economic feasibility studies has been calculated in relation with payback period with the changes of price per kWh.

Keywords: efficiency, economic, photovoltaics panel, shading devices, solar radiation.


- 46-

MPPT-based fuzzy logic controller under partially

shaded photovoltaic arrays

Mellit A. Bouilouta D. Lalili, B.Medjahed, C. Boubakir and N. Lourci

Université de Jijel, Faculté des Sciences et de la Technologie, Laboratoire des

énergies renouvelables Jijel, Algérie.

[email protected]

Abstract

One of the main causes of reducing energy yield of photovoltaic (PV) systems is partially shaded conditions. Under these conditions, the power-voltage characteristics get more complex with multiple peaks. Classical algorithms (such as P&O and IncCond) fail to track the global maximum power point effectively if the PV array is partially shaded. In this paper, A complete simulation of MPPT-based fuzzy-logic controller is developed under Matlab/Simulink. To show the effectiveness of this technique, static and dynamic load have been used. Results show that the fuzzy logic technique could be used to track the global MPP under partially shaded PV arrays.

Keywords: Photovoltaic, partially shaded conditions, rapid variation, static and dynamic

loads, MPPT Fuzzy logic controller.


- 47-

Sliding mode control of an active filter for grid

connected PV system based on 3-level H-Bridge

inverter

Mohamed Néjib Ben Nasr KHAMMESSI1, Anis KEBIR

2,

Anis SELLAMI2

1U.R SICISI.

2U.R C3S.

[email protected]

Abstract

This paper presents a sliding mode controller of a single-phase 3 level H-bridge grid-tied inverter. A Maximum Power Point Tracking (MPPT) algorithm was implemented. The latter is based on the inverter output power to assure optimal operation of the inverter when connected to the power grid. Sinusoidal Pulse Weight Modulation “SPWM” technique is proposed to be used for comparison between carrier signal and developed sliding mode reference. This approach has been constructed on the base of a time-varying sliding surface to control the sinusoidal inductor current and solar array power simultaneously. The proposed system can avoid the current overshoot and make optimal design for the system components. The structures of a proposed system are simple, but they show the significant reduction of the THD. The introduction of a smoothing parameter in the nonlinear component of new proposed control law shows a signification reduction of undesirable chattering problem. Simulations results confirm that the injected current to the grid tracks the reference current with a very low error.

Keywords: PV generator, MPPT, H-bridge inverter, grid connected, sliding mode control.


- 48-

Comparative study of the Moroccan power grid

reliability in presence of photovoltaic and wind

generation

M. OUKILI 1, S.ZOUGGAR

1, M. SEDDIK

1, T. OUCHBEL 1, F. VALLEE

2,

M. El HAFIANI 1, A. AZIZ

1

1Laboratoire de Génie Electrique et Maintenance (LGEM) - Ecole Supérieure de

Technologie (ESTO) – Université Mohammed 1er Oujda – Maroc. 2Service de Physique Générale – Faculté Polytechnique – Université de Mons -

9 Rue de Houdain B7000 Mons- Belgique.

[email protected]

Abstract

The photovoltaic sector in Morocco is a serious option for the future. The integration of this type of energy into the grid has a considerable effect on the adequacy of the grid. The objective of this work is to assess the reliability of the Moroccan power grid at the hierarchical level I (HLI: load coverage under the assumption of infinite node) using a non-sequential Monte Carlo simulation in which photovoltaic generation is introduced. In order to lead such a study, a model was used in order to calculate the hourly solar radiation and to determine the time evolution of the electrical power produced by photovoltaic power plants. Finally, we also compared the impact of both PV and wind generations in terms of adequacy of the Moroccan electrical supply.

Keywords: Reliability, renewable energy, photovoltaic energy, wind energy, solar

radiation


- 49-

Validation of a laboratory-scale protocol to study

the performances of NiO/NiAl2O4 in fixed bed

reactor for CLC process

Lucia BLAS1, Sophie DORGE

1, Patrick DUTOURNIE

1, A. LAMBERT

2

1 Laboratoire Gestion des Risques et Environnement, Université de Haute

Alsace, 3 bis rue Alfred Werner, 68093, Mulhouse, France. 2 IFP Energies Nouvelles, BP3, 69360 Solaize, France.

[email protected]

Abstract

Chemical Looping Combustion (CLC) is a promising technique for CO2 capture. This process is based on oxy-combustion where the oxygen required for combustion is conveyed by an oxygen carrier, e.g. a metal oxide. This work deals with the elaboration of a new experimental protocol at laboratory-scale to study the performance of oxygen carriers in a fixed bed reactor. Tests were performed at high temperature (700°C – 900°C) on NiO/NiAl2O4, a promising oxygen carrier, with CO as combustible. The results obtained in fixed bed reactor reveal the stability of the reduction capacity of the oxygen carrier during oxidation/reduction cycles owing to an efficient regeneration step and its good performance at high temperature (700°C – 900°C). Moreover, in this range of temperature and CO concentration, the total reduction capacity of the oxygen carrier and the reduction kinetic seem not to be a function of the operating temperature.

Keywords: Oxygen carrier, Chemical Looping Combustion, oxy-combustion, CO

oxidation, high temperature operation


- 50-

Control of induction motor pumping system

supplied by a photovoltaic generator

Najet REBEI, Othman HASNAOUI, Houda BRAHMI.

Unit of research (RME), INSAT, Tunisia Centre urban Nord, B.P. N°676,

1080 Tunis Cedex, Tunisia.

[email protected]

Abstract

The objective of the present work is to study a photovoltaic water pumping system that consisting of a photovoltaic generator, an inverter, an induction motor and a centrifugal pump as mechanical load. The model used for global simulation is a closed loop model: the voltage output of PVG model is coupled with the voltage input of a converter-induction motor model; the current output of this latter is coupled with the current entry of the PVG. The model selected for the study of the photovoltaic generator it the well-known exponential analytical model. The inverter is controlled with a FOC-PWM law and assuming ideal switches. The induction motor model is based on the classic dynamic model in the dq orthogonal Park reference frame. Simulations results confirm the working of the complete model. The motor supply is also ensured in all insulation conditions. Simulation results show the effectiveness and feasibility of such an approach.

Keywords: photovoltaic generator, FOC control - PWM control; inverter, induction

motor, centrifugal pump.


- 53-

PV Maximum Power Point Tracking under rapidly

changing irradiance: control scheme investigation

A. ABDELSALAM1, Ahmed HELAL

1, Nahla ZAKZOUK

1 and

B.W.WILLIAMS2

1 Arab Academy for Science & Technology and Maritime Transport, Egypt.

2 University of Strathclyde, U.K.

[email protected]

Abstract

In this paper, various control schemes, for maximum power point tracking (MPPT) in standalone photovoltaic (PV) systems, are investigated. Their effect on the system's transient and steady-state performance, under varying irradiance condition, is studied by comparing three incremental conductance (IncCond.)-based models applying: (i) open-loop control, (ii) closed-loop control with classical PI controller, and (iii) closed-loop control with adaptive fuzzy-tuned PI controller. Among the three models utilizing variable-step IncCond. MPPT algorithm, the one employing adaptive PI controller shows the best performance from steady-state and transient point of view. Then, in order to study the impact of the applied MPPT algorithm on the system response, an open-loop fuzzy-logic MPPT technique is presented and compared with the third IncCond. model. The performance of the fuzzy-based MPPT model outweighs the latter regarding the transient overshoot and has a relatively simpler structure. However, it's slower to reach the MPP and experiences more, yet acceptable, steady-state oscillations around the MPP especially with severe irradiance changes.

Keywords: PV array, IncCond. algorithm, Adaptive fuzzy-tuned PI controller, Fuzzy-

based MPPT technique


- 56-

Application of the particle swarm optimization

algorithm "PSO" and five levels inverter in a

photovoltaic water pumping system

K.DJERMOUNI, A.BERBOUCHA, K.GHEDAMSI, D.AOUZELLAG

Laboratoire de maitrise des énergies renouvelables, Université de Bejaia.

[email protected]

Abstract

Maximum power point tracking (MPPT) must usually be integrated with photovoltaic (PV) power systems so that the photovoltaic arrays are able to deliver the maximum power available. The present paper proposes an approach for improving and optimizing the performance of a stand-alone photovoltaic pumping water system by maximum power point tracking (MPPT) method, based on Particle Swarm Optimization (PSO) and improving the quality of energy by the use of a five-level inverter controlled by space vector pulse width modulation (SVPWM).

Keywords: Particle swarm optimization, multilevel inverter, space vector pulse width

modulation


- 57-

A non linear control of photovoltaic system based

on discrete sliding mode

Br. KHIARI1, M. KALFA

1, N. ZITOUNI

1, A. SELLAMI

2, A .MAMI

3

1 Research Center of Energy B.P. 95 Hammam-Lif 2050 Tunis, TUNISIA.

2 High school of Science and Technology, Tunis, TUNISIA.

3 Science faculty of Tunis, Tunis 1002, Tunisia.

[email protected]

Abstract

The objective of this research is to implement a discrete sliding mode control scheme for buck DC-DC converter to extract a maximum PV power and to analyze its erformance under various climatic conditions. The proposed strategy is based on the discrete sliding mode control theory of nonlinear systems. The input reference

of the regulation loop is given by a maximum power point research algorithm and the tracking of this reference is made using the discrete sliding mode control. The theory and simulation development are published in [1], in this work we propose the experimental system and results to proof the simulations one.

Keywords: Maximum Power Point Tracking (MPPT), Discrete Sliding Mode Control

(DSMC), experimentalresults.


- 58-

Effect the thickness and bending angle as a function

on electrical resistance of Aluminum thin films

deposited on Flex and Tedlar (TPT) flexible

substrates for solar cell

FALAH. I. Mustafa1, Zainb. ABDSALAM

2, Ali. Mohssen

3

1,3Solar energy research center, Renewable energy Directorate, Ministry of

science and Technology, Baghdad, IRAQ. 2Al-Mustansiriyah University, College of Education, Physics Department,

Baghdad-IRAQ.

[email protected]

Abstract

In this work, we study the effect of thickness and bending angle of Al-Electrode thin films deposited on Flex and Tedlar (TPT) substrate related to electrical resistance measurements (Ohm), the thickness of Aluminum thin films 150nm, 200nm and 400nm. The bending angle used between 0-180 degree and the thickness of Flex and Tedlar polymer were 0.5 mm. The result showed the electrical resistance decrease with increase of Al thin film thickness on polymer and no effect of bending angle. The Tedlar (TPT) substrate more efficient from flex substrate and useful for flexible solar cell manufacturing.

Keywords: Polymer, thin films, solar energy


- 59-

Determination of the monthly and yearly electrical

output power of a PV panel using a Robot

Manipulator for sun tracking

CHAÏB Ahmed, KESRAOUI Mohamed, AISSANI Yacine

Applied Automatics laboratory, University M’hamed Bougara, Avenue de

l’indépendance, 35000 Boumerdes, Algeria.

[email protected]

Abstract

In this paper the effect of the solar PV panel orientation in addition to the ambient temperature and solar irradiations on the delivered electrical power is analyzed. First a solar photovoltaic panel system using a robot manipulator for one and two axes sun tracking has first been described. The captured monthly and yearly solar irradiances for Algiers have been computed and the corresponding curves plotted. The PV panel electrical model and mathematical equations have been presented. Simulation of the system using MATLAB software was performed. Power efficiency for different irradiations and temperatures has been plotted. The PV panel system electrical output power for any day in the year has been determined for the one and two axes tracking situations. The results obtained showed that the two axis tracking gives substantial difference with respect to one axis tracking for winter and spring times. However in summer time or autumn it is economically better to use one axis tracking since the added power value is negligible.

Keywords: Control model, Robot manipulator, Solar panel, Solar radiation, Tracking

System.


- 60-

Experimentation and performances of a PV water

pumping system

Djamila REKIOUA ZIANI1 , Ahmed.MOHAMMEDI

1, Toufik REKIOUA

1 and

Zoubir MEHLEB2

1L.T.I.I Laboratory, University of Bejaia 06000, Algeria. 2Electro – Mécanique MEHELEB Frères (SEM) Bejaia.

[email protected]

Abstract

In this paper, we present different performances of a photovoltaic water pumping system. A prototype of experimental bench in installed in our laboratory (LTII). We present a model to characterize the moto-pump subsystem used in PV pumping installations. The model expresses the water flow output (Q) directly as a function of the electrical power input (P) to the motor-pump, for different total heads. The obtained resultsillustrated by curves are represented and analyzed.

Keywords: Photovoltaic, water, pumping system, centrifugal pump, MPPT


- 61-

A Modern MPPT Control Algorithm Based on -

MPP Pass-through Detection and -acceleration

Mechanism

Mohammed SETTI, Jaouad TANOUTI, Abdelhak AZIZ, Zdravko KANEV, El

Mamoun AZIZ

Electrical Engineering and Maintenance Laboratory,

Higher School of Technology, 473, Oujda, Morocco.

[email protected]

Abstract

A modern Maximum Power Point Tracking (MPPT) method based on the incremental conductance (IncCond) control algorithm is discussed. This method features a variable step iteration of duty ratio to get over the trade-off between dynamic performance and steady state oscillation around maximum power point (MPP). Moreover, in the aim to get an excellent precision and a swift response independently of the climatic conditions, an alpha-MPP pass-through detection and beta-acceleration mechanism are introduced.

Keywords: Photovoltaic, Maximum Power Point Tracking(MPPT), incremental

conductance (IncCond), variable step size.


- 62-

Novel pyridinium iodide containing siloxane high

performance electrolyte for dye-sensitized solar cell

Soon-Ho Lee, Young-Don Lim, Young-Tae Jeon, Young-Gil Cho, Sang-Young

Lee1 and Whan-Gi Kim

1Department of applied chemistry, Konkuk Univ., Chungju, 380-701, Korea

[email protected]

Abstract

A new type of solid and gel-state ionic electrolytes based on siloxane pyridinium iodides was synthesized and used in dye-sensitized solar cells. The resulting electrolytes were characterized by 1H NMR spectroscopy, TGA and diffusion coefficient. The synthesized siloxane pyridinium iodide electrolytes have characteristics of different chain length of siloxane moieties. And thermogravimetric analysis showed good thermal stability. Among the three SiDPIs based electrolytes, a DSSC employing the SiDPI2 gives an open circuit voltage of 0.704V, a short-circuit current of 15.85mA/cm2 and conversion efficiency of 6.8% under light intensity of 100mW/cm2. In addition, the performance of the DSSCs showed relatively reasonable compared with the propylpyridinium iodide (PPI) electrolyte.

Keywords: Ionic liquid, electrolyte, dye sensitized solar cell, pyridinium iodide, DSSC.


- 63-

An improved Maximum Power extraction control

for a photovoltaic water pumping system

Soulaymen KAMMOUN, Souhir SALLEM, MBA KAMMOUN

e-mail: [email protected], [email protected], [email protected],

[email protected], [email protected], [email protected]

[email protected]

Abstract

The most important concern in photovoltaic system is load matching especially when we talk about AC loads, and this is because of the operating point of the photovoltaic panel(s)which always moves according to irradiance; in this case, almost all photovoltaic water pumping systems use a DC – DC converter (Chopper) to ensure the load matching. The use of two converters (DC – DC and DC – AC) for AC loads reduces more the system yield. That‟s why in this paper we suggest a new strategy of photovoltaic water pumping which doesn‟t use a DC – DC converter for load matching. This strategy imposes an operating regime for the single phase induction motor (Operating frequency of the motor) that drives the pump; this operating regime is directly related to the irradiance which makes the operating point of the photovoltaic panel(s) always near the Maximum Power Point (MPP). For the control of the single phase induction motor we use the scalar control to avail from its simplicity of implantation in a microcontroller. The variation of voltage and frequency is assured by a PWM controlled single phase inverter.

Keywords: PV Water pumping Load matching Amorphous technology Single phase

inverter PWM Single phase induction motor Centrifugal pump Stand-alone

system


- 64-

Effect of BSF on crystalline silicon solar cell using

TCAD Silvaco Software

Souad TOBBECHE and Mohamed Nadjib KATEB

Laboratoire des matériaux semi-conducteurs et métalliques, Faculté des

Sciences et de la Technologie, Département de Génie-Electrique,

Université de Biskra,B.P 145, Biskra 07000, Algérie.

[email protected]

Abstract

Back surface field (BSF) becomes more and more interesting in order to decrease the back surface recombination velocity and to increase collection efficiency. In this work, we present the simulation results of the technological parameters and the electrical characteristics of a crystalline silicon solar cell with BSF, using two-dimension (2D) software, namely TCAD Silvaco (Technology Computer Aided Design). The J-V characteristics and the external quantum efficiency (EQE) are simulated under AM 1.5 illumination. A comparison between two cells, one without BSF (structure n+p), the other with one BSF (structure n+pp+), was made. By creating a BSF on the rear face of the cell the short circuit current density increases from 28.55 to 30.54 mA/cm2, the open circuit voltage from 0.6 to 0.631 V and the conversion efficiency from 14.19 to 16.06%. A clear improvement of the spectral response is obtained in wavelengths ranging from 0.65 to 1.1 µm for the solar cell with BSF. The optimization of the BSF parameters provides that is possible to achieve a solar cell with a high efficiency of 16.19%, a high open circuit voltage of 0.633 V, a high short circuit current density of 30.66 mA/cm2 and a high fill factor of 0.833 if the p+ thickness is of 0.35-0.39 µm and the p+ doping dose is about 2x1014 cm-2.

Keywords: Simulation, Athena , Atlas , TCAD Silvaco , Silicon solar cell , BSF.


- 65-

Predictive Power Control for Photovoltaic Grid

Connected System

Kamel BARRA and Djamel RAHEM

Larbi Ben M’hidi university, Oum El Bouaghi, 04000. Algeria.

[email protected]

Abstract

The paper presents an improved predictive power control of a photovoltaic conversion chain connected to a grid based on finite states space model of the converter. The proposed control algorithm selects the switching state of the inverter that minimizes the error between active and reactive power predictions to their computed values for all different voltage vectors. The optimal voltage vector that minimizes a cost function is then applied to the output of the power converter. The proposed predictive control strategy uses only one sample time prediction and it is very intuitive since it is very simple and provides best performances compared to other modulation techniques such as PWM and SVM (low cost, fast dynamic response, simple implementation).

Keywords: Photovoltaic grid conversion chain, predictive control, finite state-space

model, cost function.


- 66-

Application of Adaptative Fuzzy logic controller in

Photovoltaic pumping System

Djamila REKIOUA ZIANI, Samia BENSMAIL

Department of Electrical Engineering, Laboratory LTII, University of Bejaia,

06000, Algeria.

[email protected]

Abstract

In this paper, we make an application of adaptive fuzzy logic controller (AFLC) to a photovoltaic pumping system. A comparison of results obtained with AFLC and with those obtained with classical control Perturb & observ.(P&O) is made. For the subsystem pumping, we use the model expresses the water flow output (Q) directly as a function of the electrical power input (P) to the moto-pump, for different total heads. The pumped water is used to satisfy the domestic needs of a family during two different days with an example of profile insolation. The results obtained by simulation using Matlab/Simulink are presented.

Keywords: Photovoltaic, Maximum power point tracking, P&O, Adaptative fuzzy logic

control, Pumped water.


- 67-

Channel length effect on the temperature field in a

Metal-Oxide-semiconductor Field Effect Transistor.

Faouzi NASRI, Fraj ECHOUCHENE, Hafedh BELMABROUK

University of Monastir

Faculty of Sciences of Monastir

Electronics and Microelectronics laboratory.

[email protected]

Abstract

The miniaturization of semiconductor devices tends to decrease the density of dissipated power.

Therefore it is necessary to investigate the influence of the channel length and the electro- thermal properties on the performance of semiconductor devices, because the heat transfer in the channel is induced by Joule effect.

In this present work, we solve numerically, coupled Poisson, transport and heat equations in a two dimensional configuration using Finite Element Method. The heterostructure to model consists in a Metal-oxidesemiconductor field effect transistor with different channel lengths ranging from 14 to 100nm. Thermal properties of the transistor device have been investigated for different temperature boundary conditions. As has been found, the change in temperature boundary at the boundary can lead to a significant decrease in the local lattice temperature.

Keywords: MOSFET; heat transfer, transport model, short channel effect


- 68-

PV-MEMS: PV Meteorological & Electrical

Measurement System

Abdelghani HARRAG1,2

, Djamel SAIGAA1,

Walid BENSAADI1, Ahmed

BOUCHELAGHEM1, Mahmoud DRIF

1, Djamel BOURAS

1

1Department of Electronics, Faculty of Technology, Mohamed Boudiaf

University,BP 166 Ichbilia, Msila 28000 Algeria. 2CCNS Laboratory, Department of Electronics, Faculty of Technology, Ferhat

Abbas University,Cite Maabouda, Setif 19000 Algeria.

[email protected]

Abstract

This paper presents the design and development of a PIC18F452 microcontroller-based data acquisition system in order to monitor the characterization and performance of a photovoltaic (PV) system. It described the development of automated monitoring measurement system for a small scale solar Photovoltaic (PV) plant. The study used a developed microcontroller-based data acquisition to store and record data of all parameters. Data such as voltage, current, temperature, pressure and power were measured, stored and displayed using sensor microcontroller (PIC) data acquisition module with Visual Basic/PHP software. It is a low cost PC-based monitoring system that can display data and generate reports in the form of tables and graphs. The developed GUI also allows us to store the collected data locally (in SD card or the PC disk) or far away (by email or FTP connection). The advantages of using the system are the monitoring of the PV system performances locally and remotely from where the data were stored as well as retrieve information on-line. Furthermore, the system also allows the collection of data to be stored for long periods of time without being interrupted.

Keywords: Photovoltaic, Data acquisition system, PV curve, Visual Basic, PHP, Remote

Sensing.


- 69-

Sliding mode observer and control of the solar

photovoltaic water pumping systems without

battery storage

Mohamed Abdellatif KHALFA1, 2

, Brahim KHIARI2 and Anis SELLAMI

1,2

1High school of Science and Technology (ESSTT), Tunis, TUNISIA.

2Photovoltaic Laboratory, Research Center of Energy Borj-Cédria, TUNISIA.

[email protected]

Abstract

In this paper, the modeling, the sliding mode observer and control of the photovoltaic (PV) water pumping systems without battery storage are detailed. The proposed system is suitable for rural communities in developing countries because it is reliable, affordable and easy to maintain. This work is motivated by the need to track the maximum power of the PVG in presence of climatic variation conditions. This objective is reached by the application of a sliding mode control approach (SMC). First, the different models of elements composing the whole system are presented: the PVG, the DC/DC converter, DC/AC inverter and the induction motor pump (IMP). To reconstruct the rotor flow, a sliding mode observer is applied. Then, we propose a sliding mode controller which insures the convergence of the rotor speed and the square of the rotor flux magnitude to their references. Finally, simulation results are presented to show the robustness and effectiveness of the proposed control theory.

Keywords: Photovoltaic pumping system; maximum power point tracking; sliding mode

observer; sliding mode control.


- 70-

A study of optical and structural properties of

hydrogenated amorphous silicon films prepared at

different conditions of pressure and time deposition

Sana BEN AMOR, Wissem DIMASSI, Hatem EZZAOUIA

Photovoltaic Laboratory Research and Technology Centre of Energy, Borj-

Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia.

[email protected]

Abstract

Two sets of hydrogenated amorphous silicon (a-SiH) thin film samples were prepared by plasma enhanced chemical vapor deposition (PECVD) using H2 diluted SiH4 gases at different conditions of pressure and time deposition. The values of optical parameters (refractive index, thickness and energy gap) were calculated from the transmission spectra in the range 250-2500 nm. The surface morphology of each sample was scanned by atomic force microscopy (AFM) on a 1_1 mm area at a scan rate of 1 kHz.To affirm the amorphous character of the different layers, a study by IR-X-ray diffraction spectra was down.

Keywords: hydrogenated amorphous silicon, PECVD, pressure, time deposition


- 72-

Modeling and simulation of a single phase

photovoltaic system connected to the network under

the islanding phenomenon

LAOUR Mohammed, MAHRANE Achour, AKEL Fethi, BENDIB Douadi,

CHIKH Madjid

Solar Development Equipment Unit (UDES), Tipaza 42415, Algeria.

[email protected]

Abstract

When photovoltaic systems are connected to the grid, in the absence of the latter islanding situations occur. In this configuration, it is imperative that the inverter automatically disconnects from the grid without remaining any residual voltage that can be dangerous for the plants and stakeholders. It is important to detect the islanding situation. For this purpose several techniques are used. We present in this article the implementation of the method called Active Frequency Drift (AFD) in the control of a single phase photovoltaic inverter. The simulation results obtained show that the developed algorithm detects the islanding phenomenon in the time approaching that required by the IEC and IEEE standards that secures the PV system connected to the grid.

Keywords: PV systems, electrical grid, islanding detection methods, single phase PV

inverter, distributed generation systems


- 73-

PV-C2ST: PV Characteristic Curves System Tracer

Abdelghani Harrag1,2

, Djamel Bouras1, Walid Bensaadi

1

1Department of Electronics, Faculty of Technology, Mohamed Boudiaf

University,BP 166 Ichbilia, Msila 28000 Algeria. 2CCNS Laboratory, Department of Electronics, Faculty of Technology, Ferhat

Abbas University,Cite Maabouda, Setif 19000 Algeria.

[email protected]

Abstract

This paper presents an improved electronic circuit for testing photovoltaic (PV) modules by tracing their I-V and P-V characteristics. It uses the single-ended primary-inductance converter (SEPIC) to emulate a variable resistor. The emulated resistor value is modified through the duty cycle of the PWM signal of power MOSFET transistor driving the DC-DC SEPIC converter. The PWM signal is generated by microcontroller which also manages the measurement of PV current and voltage. The measured values are first conditioned using precision electronic circuits and then transmitted to the LabVIEW virtual instrument developed software via RS232 connexion. LabVIEW software allows processing or displaying characteristics as well as a full control of our system parameters. The experimental results show the capabilities of our system to measure and draw characteristics of PV modules in real-time meteorological test conditions, allowing us comparing them with those provided by the manufacturer. In spite of these important characteristics, the developed electronic circuit keeps the advantages of low cost and simplicity compared to expensive commercial ones.

Keywords: Photovoltaic systems, PV characteristics, DC-DC converter, SEPIC,

LabVIEW, PIC microcontroller


- 74-

Remote Monitoring and Performance Analysis of

Stand-Alone PV Systems: the Case Study of a PV-

Powered Outdoor Refrigerator

GIUSEPPE MARCO Tina1, ALFIO DARIO Grasso

1 and ANDREA Cagnasso

2

1University of Catania (Italy) - Dipartimento di Ingegneria

Elettrica Elettronica e Informatica. 2Indesit Company S.p.A. - Italy.

[email protected]

Abstract

This paper describes a monitoring system for stand-alone photovoltaic systems. For the proposed system a web application has been exploited, thus allowing a remote monitoring and control. The system produces daily reports that can be elaborated off-line to calculate energy performances indices, useful not only to optimize the operation of the system but also to design a retrofit of the stand-alone system based on historical data analysis. The system has been exploited to investigate the performance of a photovoltaic-powered outdoor refrigerator. Experimental measurements executed on a prototype, show that the system works adequately in the given place (Catania-Italy) if an augmented PV array is used.

Keywords: Stand-alone PV systems, energy efficiency, PV refrigeration


- 75-

Vector Control based on fuzzy logic controller of

Induction Motor for Photovoltaic Pumping System

Sofia LALOUNI, Kassa IDJDARENE, Djamila REKIOUA

Laboratory LTII, Department of Electrical Engineering,

University of Bejaia, Algeria.

[email protected]

Abstract

Photovoltaic energy is used in different applications. The most important one is the photovoltaic water pumping system. With the increased use of this application, more attention has been paid to their optimum utilization in order to maximize the efficiency of the photovoltaic energy system. Many methods have been developed to determine the maximum power point (MPP), a comparison between perturbation and observation method (P&O) and fuzzy logic controller (FLC) is presented. The results show that, FLC carries high accuracy around the optimum point when compared to the conventional one. Next, a vector control of induction motor fed by a photovoltaic system is studied to improve its dynamic performance. The currents are controlled through a hysteresis control and two controllers are compared to control the pump speed, classical PI and fuzzy logic PI. The results show an improvement in transient response of the fuzzy logic speed controller compared to the classical one. The photovoltaic pumping system is composed of a PV generator, DC-DC converter, DC-AC converter, a vector controlled induction motor and centrifugal pump. A simulation study is presented under variable weather conditions and the results show the effectiveness of the studied method.

Keywords: Photovoltaic system, modelling, PV pumping, induction motor, speed control.


- 76-

Elaboration and Characterizations of

Nanocomposites based on Poly(9-

vinylcarbazole:Buckminsterfullerene for

Photovoltaic Applications

R. BKARI1, N. CHEHATA

1, A. LTAIEF

1, N. CHAABEN

2, F. SAIDI

3

and A. BOUAZIZ1

1Equipe Dispositifs Electroniques Organiques et Photovoltaïque Moléculaire,

Faculté des Sciences de Monastir, Avenue de l’Environnement,

5019, Monastir, Tunisia. 2Unité de Recherche sur les Hétéro-Epitaxies et Applications, Faculté des

Sciences, 5019, Mon

[email protected]

Abstract

Organic nanocomposites based on a heterojunction network between Poly (9-vinylcarbazole) (PVK) and buckminsterfullerene (C60) have been developed. To improve the spectral coverage of the PVK polymer, organic dyes such as PcH2 and Coumarin 343 have been added. The sensitization of the polymer by PcH2 and coumarin 343 leads to photoluminescence enhancement. Whilst the addition of C60 molecules to the PVK:PcH2:Coumarin 343 blend induces the PL quenching which due to the dissociation of the photogenerated excitons. Optical properties of PVK:C60 nanocomposites films were investigated. Charge transfer between the polymer and (C60) has been demonstrated through photoluminescence (PL) measurements as a function of buckminsterfullerene concentration and annealing temperature. In this study, charge transfer efficiency is obtained for an optimum concentration of C60 about 50 wt. % .

Keywords: Polymer, Buckminsterfullerene, organic dyes, nanocomposite, charge transfer


- 77-

Adaptive Fuzzy Controller Based MPPT for

Photovoltaic systems

Ouahib GUENOUNOU1, Boutaib DAHHOU

2

1Laboratoire de Technologie Industrielle et de l’Information

Université A.Mira de Béjaia, Route Targa-Ouzemour, Béjaia, Algerie. 2CNRS; LAAS; 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4,

France, Université de Toulouse ; UPS, INSA, INP, ISAE ;

LAAS; F-31077, Toulouse, France

[email protected]

Abstract

This paper presents an intelligent approach to optimize the performances of a photovoltaic system using an adaptive fuzzy controller.

The proposed fuzzy controller, is compared to (P and O) method and conventional fuzzy controller. The results obtained under different operating conditions show that the proposed fuzzy controller is much better.

Keywords: fuzzy controller, scaling factors , PV panel.


- 78-

Modeling on radial solar cells under AM1.5G

spectrum

S. TAAMALLI, F. ECHOUCHENE and H. BELMABROUK

Laboratoire d’électronique et de microélectronique, Département de Physique,

Faculté des Sciences de Monastir, Université de Monastir Tunisie.

[email protected]

Abstract

In this paper, we study theoretically solar cell having a radial shape coaxial wire. The emitter layer i.e., the exterior “shell” of the nanorod was assumed to be n-type, while the base i.e., the interior “core” of the nanorod was assumed to be p-type. Light was assumed to be normally incident on the top face of the nanorod. The density of minority carriers in the quasi-neutral regions was simulated in two modes: short circuit, and under electrical field. We studied the effect of surface velocity recombination on the evolution of the minorities carrier density for the two structures (planar and radial). We calculated the short circuit current density and the efficiency under the AM1.5 spectrum. A comparison of the efficiency of conventional solar cell (planar) and radial was performed. The short circuit current density of the conventional planar solar cell is 40mA/cm² while it is in the order 41.93mA/cm² of a radial solar cell.

Keywords: Nanorod, solar cell, radial, simulation, efficiency.


- 79-

Electrical study of doped PANi-PVDF

nanocomposites

S.SAIDI, H.DEROUICHE and A.BELHADJ MOHAMED

Photovoltaïc laboratory, Energy Research and Technology Centre.

B.P. 95, 2050 Hammam-Lif, Tunisia.

[email protected]

Abstract

In the present work, the effect of the addition of doped Polyaniline (PANI) powder on electrical properties of PVDF has been studied. For such a purpose, many samples have been prepared by adding PANI on the PVDF by different weight percentages wt% of PANI (1, 5, 10, 15 and 20%). The X-ray diffraction analysis showed crystalline structure for our all studied samples, UV spectroscopy analysis showed the absorbance and energy band gap of samples are determined from these spectra. Conductivity measurements have been reported in the temperature range of 298 - 438 K. The experimental results show that the D.C. electrical conductivity changes when the concentration of additional PANI increases, this behavior was explained by the percolation theory and the percolation threshold (pc) is determined. These result were confirmed by energy band gap measurement using the U.V spectroscopy, where this energy decrease when the concentration of the additional PANi increase. We have also seen a variation of D.C. electrical conductivity with temperature. Indeed, when temperature is increased, the electrical conductivity increases.

Keywords: nanocomposite; percolation; electrical conductivity


- 81-

Boron redistribution kinetics in strongly doped

silicon thin bi-layers during thermal activation

annealing

Salah Abadli1,2

, Farida Mansour2

1Department of Electrical Engineering, University 20 Août 1955,

Skikda, Algeria 2LEMEAME Laboratory, Department of Electronics,

University of Mentouri, Constantine, Algeria

[email protected]

Abstract

The complex boron (B) redistribution process in strongly doped silicon bi-layers structure has been investigated. A one-dimensional two stream transfer model well adapted to the particular structure of bi-layers and to the effects of strong-concentrations has been developed. This model takes into account the instantaneous kinetics of B transfer, trapping, clustering and segregation during the thermal B activation annealing. The used silicon bi-layers have been obtained by low pressure chemical vapor deposition method, using in-situ nitrogen-doped-silicon layer and strongly B doped polycrystalline-silicon layer. To avoid long redistributions, thermal activation annealing was carried out at relatively low-temperatures (700 and 850°C) for various times ranging between 15 minutes and 2 hours. The good adjustment of the simulated profiles with the experimental secondary ion mass spectroscopy (SIMS) profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the complex B redistribution profiles-shoulders kinetics.

Keywords: Boron, diffusion, silicon, bi-layers, thermal annealing


- 82-

Phosphate ore washing by NA2EDTA for cadmium

removal

Zahia Benredjem1, Assia Khelalfa

1, Saaidia Samia

1 and Rachid Delimi

1

University Badji Mokhtar Annaba, Laboratory of water treatment and

valorization of industrial wastes, Chemistry Departmemt, Faculty of Sciences,

BP 12 Annaba 23000 (Algéria).

[email protected]

Abstract

This paper discusses the extraction of cadmium from phosphate ore by the washing method. Various parameters were investigated for the cadmium extraction from phosphate ore. The results from extraction tests showed that cadmium extraction depends on the nature and concentration of the extracting agent, the liquid/phosphate ore ratio, the temperature and the solution pH. The effi ciency of the nine extracting agents for removing cadmium from phosphate ore was found to be in the order: Na2EDTA > citric acid > tartric acid > ammonium citrate > calcium chloride > ammonium acetate > ammonium chloride > oxalic acid > ammonium hydroxide. In this study cadmium extraction kinetics was best described by the product layer diffusion control model.

Keywords: Phosphate ore washing, Cadmium, Environment, Extraction, Chemical

processes, Optimization


- 85-

Solar Thermal Energy

‘STE’

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-STE-49/O

- 87-

Design and Test of Continuous Operation Modified

Solar Still

N. M. KHATTAB and E. S. METTAWEE

Solar Energy Dept., National Research Centre, Egypt.

[email protected]

Abstract

One of the viable options to deal with the water problem is the conversion of saline water to potable water through water desalination by solar energy. Solar stills represent a most attractive and simple technique among other distillation processes. Given all their merits, solar stills face the problem of low productivity compared to their costs. So, the aim of this work is to come up with a solar still design and operation that can enhance and make use of different heat sources in the system such as using reflectors, using double still basin and use heat waste to ensure continuous operation during night to optimize its productivity with minimum costs to reach an economically viable model. In this study, small-scale modified multi basin solar stills (two basins) suitable for family uses is designed, manufactured and tested in the Solar Energy Department with the target of estimating the total quantity of water distilled per day per unit area under actual climatic conditions of Egypt. Experimental results show that the productivity of the double basin still increases by about 57.3% than simple solar still. Using reflector improve the double basin productivity by 11% while using both heat recovery and reflector increases by 39.6%

Keywords: Simple Solar still, Double Basin Still, Solar Reflectors, Heat Recovery,

Continuous operation

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-STE-89/P

- 88-

Theoretical study of a solar modular still under

Algerian weather condition

Rabah KERFAH1, El ghalia FILALI

2, Zeghmati BELKACEM

3

1 FIMA Laboratory, Khemis Miliana University Khemis Miliana, Algeria.

2 Advanced Mechanics Laboratory, U.S.T.H.B. Algiers, Algeria.

3 LAMPS,Perpignan University ,Perpignan, France.

[email protected]

Abstract

In this paper, we present a numerical study of a modular solar distillation system working in natural convection mode. This still is constituted of a streaming plan solar collector and a condensing chamber. Equations governing the heat and mass exchange are established using the nodal method. The operation of the still is simulated for a typical day of the month with the weather conditions of Algiers (Algeria). Results show that solar radiation is the most important parameter of the system operation. The evaporation amount during typical day of April is about 3,5 kg. the condensation yield is 3,0 kg. The efficiency is 18% and 20% of the solar collector and the condensation chamber respectively. The temperature of the produced hot water reached as high as 40°C, which is good enough for domestic use.

Keywords: condensation, evaporation, distillate, natural convection, modeling


- 90-

Numerical study of evaporation by mixed

convection of a binary liquid film flowing down the

wall of two vertical plates

Abdelaziz NASR, Abdesslem JBARA, Chokri DEBBISSI HFAIEDH

and Sassi Ben NASRALLAH

Laboratoire d’Etudes des Systèmes Thermiques et Energétiques,

Ecole Nationale d'Ingénieurs de Monastir, Rue Ibn El Jazzar,

5019, Monastir, Tunisie.

+ Corresponding author. Tel. 216 73 500 511, Fax. 216 73 500 514

[email protected]

Abstract

This paper focuses on a numerical analysis of the evaporation of binary liquid film flowing on one of two parallel vertical plates under mixed convection channel. The first plate is externally submitted to a uniform heated flux q1 and wetted by a film while the second one (y = d) is dry and isothermal. The liquid mixture consists of water (the more volatile component) and ethylene glycol while the gas mixture has three components: dry air, water vapour and ethylene-glycol vapour. The set of non linear and coupled equations expressing the conservation of mass, momentum, energy and species in the liquid and gas mixtures is solved numerically using a finite difference method. The results concern the effects of the inlet parameters in the gas and in the liquid mixtures on the water evaporation rate. As was found in some former work, this study shows that it is possible to evaporate in the same conditions more water than if the film at the entry was pure water only. The main objective of this study is to clarify the existence and the physical origin of this unexpected phenomenon.

Keywords: Binary mixture, Binary liquid film, Evaporation, Combined heat and mass

transfer, Mixed convection, Laminar flow.


- 91-

Thermal properties study of a solar water heater

tank with a mantle exchanger

CHIKHI Mourad, SELLAMI Rabah and KASBADJI MERZOUK Nachida

Unite of Solar Equipment Development; UDES

Route Nationale N°11 BP 386, Bou-Ismail,

42415, Wilaya Tipaza, Algeria.

[email protected]

Abstract

The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For development solar water heaters, the incentive programs are supported by the Algerian government to generalize the using of this kind of energy especially in Sahara. This study is a part of program to develop a new solar water heater in UDES (Algeria). In this research work, the thermal performance of a solar water heater with a mantle heat exchanger is investigated numerically using Comsol Multyphysics software. The objective is to investigate the influence of the mantle heat exchanger thickness on the performance of solar water heaters. The results show, for 160 liters capacity of the solar water heaters tank, the 13mm of the heat exchanger thickness leads to improve the efficiency of the solar water heater.

Keywords: Renewable energy sources, solar water heaters, a mantle heat exchanger,

thermal performance,Comsol Multyphysics software.


- 93-

The effects of volumetric flow rate and inclination

angle on the performance of a solar thermal

collector

IHADDADENE Razika1, IHADDADENE Nabila

1, Bey MADANI

2

and HAMDIBACHA Fatima Zohra 3

1Department of Mechanical Engineering, M’sila University, Algeria

2 Laboratory of fluid Mechanics, M’sila University, Algeria. 3Laboratory of fluid Mechanics, M’sila University,Algeria.

[email protected]

Abstract

A solar collector is a device that converts solar energy into heat. This paper presents an experimental study on the influences of volumetric flow rate and inclination angle on the performance of a solar collector. The tests were conducted on a solar energy demonstration system (ET 200). Which consists of a solar collector, storage tank, a control and command cabinet and high power lamp simulating solar energy. For radiation intensity of 1,033 kW/m² and an inclination angle of 0°, the results showed that the efficiency of the collector followed a linear relationship versus the flow rate and presented a coefficient of correlation (R²) of 0.9898. Similarly, the increase in the inclination angle 0° to 60° decreased the effectiveness of the collector. It followed a linear relationship with a coefficient of determination (R²) of 0.967. It is important to operate at higher mass flow rates and take the collector angle of 0° in order to reach its meaning full efficiency.

Keywords: Solar energy, solar storage collector, volumetric flow rate, collector

inclination, instantaneous collector efficiency.


- 94-

Performance evaluation of condensation-irrigation

solar system under arid climate conditions

Wafa CHOUAIEB *, M. Thameur CHAIBI

*Institut National de Recherche en Génie Rural Eaux et Forets, BP 10,

Ariana 2080, Tunisia.

[email protected]

Abstract

Scarcity of water, major critical concern in arid areas, has led to the use of low-quality irrigation water in agriculture. Water quality used for agriculture has to be reduced to a sustainable level that is also adapted to the environment. This paper presents the performance of a pilot Condensation Irrigation solar system (CI) in Tunisia under arid climate conditions. The objective of this study was to investigate the potential of this combined solar system for producing fresh water as an alternative source for irrigation in a greenhouse. Preliminary testing of the CI system performance showed that moisture amounts in the buried pipes remain high for the sunny and cloudy days and dew condensation is processing mainly at night and early morning time. Hence, the produced fresh water satisfies about 15% the maximum crop water requirements during the growth period where the tomato crops are most sensitive to water deficit. Recommendations for design improvements of system are suggested.

Keywords: Subsurface irrigation, Performance system, System design, Solar desalination,

Evapo-condensation


- 95-

Numerical and experimental investigation of

thermosyphon solar water heater

K.ZELZOULI, R.SEBAI, W.CHABANI, A.A.GUIZANI, C.KERKENI

Thermal Processes Laboratory (LPT), Research and Technology Center of

Energy, Borj Cedria B.P N°95 2050-Hammam Lif-Tunisia.

[email protected]

Abstract

This study presents a numerical and experimental analysis of the thermal performance of a solar water heater using a collector-storage thermosyphon system. Each component is tested separately using the HP-VEE program, and then we tested the complete system. During the period of test of the flat plate collector using different inlet water temperatures, the difference water temperature DT between inlet and outlet and the thermal efficiency are levels than 8°C and 74% respectively. Horizontal storage tank is tested in the purpose to known its loss coefficient. In the complete system test, draw-off volume is measured and subtraction of temperature as function of volume is calculated. In the numerical simulation, multimode approach with DIFFEQ solution technique is used to describe energy change in the stratified thermal storage tank. Numerical results of the collector and the complete system simulation respectively are given a very good agreement with the experimental with an error less than 5%.

The confirmation of numerical model with the experimental gave access to optimize the system, using the heat losses from the collector and storage tank as input parameters. Results are shown that energy stored strongly influenced by thermal losses from solar collector than losses from the storage tank.

Keywords: Thermal storage tank; Collector-storage; Thermosyphon; Numerical

investigation.


- 96-

Thermal performance of an integrated collector

storage solar water heater (ICSSWH) with phase

change materials (PCM)

Monia CHAABENE1, Hatem MHIRI

1, Pholippe BOURNOT

2

1 Unité de thermique et thermodynamique des procédés industriels, Ecole

Nationale d’Ingénieurs de Monastir,route de Ouardanine,

5000 Monastir, Tunisie. 2 IUSTI, UMR CNRS 6595, 5 Rue Enrico Fermi, Technopôle de Château-

Gombert, 13013 Marseille, France.

[email protected]

Abstract

In this paper, we propose a numerical study of an integrated collector storage solar water heater.

Two numerical models in three-dimensional modeling are developed. The first one which describes a sensible heat storage unit (S H S U), allowing validating the numerical model. Based on the good agreement between numerical results and experimental data from literature, and as this type of solar water heater presents the disadvantage of its high night losses, we propose to integrate a phase change material (PCM) directly in the collector and to study its effect on the SWH thermal performance. Indeed, a second 3D CFD model is developed and a series of numerical simulations are conducted for different designs of SWH which differ in the radius of this PCM layer (R = 0.2m, R = 0.25m and R = 0.3m). The PCM used in this study is the RT42- graphite. Numerical results show that the sensible heat storage unit performs better during the day-time period, regarding the water average temperature. Regarding the night operating of this solar water heater, it is found that the latent heat storage unit is more effective as it allows lower thermal losses and better heat preservation.

Keywords: CFD simulation, integrated collector storage solar water heater, phase change

materials, thermal performance, night losses.


- 97-

Modeling study of vacuum membrane distillation

under with coupling colar

Mokhless BOUKHRISS1, Khalifa ZHANI

1 and Habib Ben BACHA

2

1LASEM (Laboratory Electro-Mechanical Systems), National Engineering

School of Sfax,B.P. W3038, Sfax, Tunisia. 2University King Saud University.

[email protected]

Abstract

This The membrane distillation is a process vacuum evaporative using porous membranes such as physical barriers between a liquid and a permeate gas. The vaporization takes place in the liquid / membrane under vacuum. In this process the heat transfer and mass are coupled.

The objective here is to determine the operating conditions for a transfer of material importance and low energy consumption in a hollow fiber module applied to water desalination and study modeling the operation mode of the different compartments of the desalination process seawater by the membrane under vacuum and coupling solar energy to describe the behavior of the membrane under vacuum with a numerical simulation to determine the outlet temperature.

Keywords: water desalination, membrane vacuum solar collector simulation.


- 99-

Enhancing the stepped solar still performance using

internal reflectors

Z.M. OMARA 1, A.E. KABEEL

2 and M.M. YOUNES

1

1Mechanical Engineering Department, Faculty of Engineering,

Kafrelsheikh University, Kafrelsheikh, Egypt. 2Mechanical Power Engineering Department, Faculty of Engineering,

Tanta University, Tanta, Egypt.

[email protected]

Abstract

This paper presents a modification of stepped solar still through internal reflectors. A comparison study between modified stepped solar still with trays (5 mm depth x 120 mm width) and conventional solar still was carried out to evaluate the developed desalination system performance under the same climate conditions. The effect of installing a reflecting mirrors on the vertical sides of the steps of stepped still on the distillate productivity was investigated. An experimental as well as theoretical investigation is carried out. The results indicate that, during experimentation the productivity of modified stepped solar stills with and without internal reflectors is higher than that for conventional still approximately by 75% and 57 % respectively. Also the daily efficiency and estimated cost of 1 l of distillate for modified stepped with and without internal reflectors and conventional solar stills are approximately 56% - 0.035 $, 53% - 0.037 $ and 34% - 0.045 $ respectively.

Keywords: Solar still, Solar desalination, Solar distillation, stepped solar still, reflectors.


- 100-

Tomatoes drying in forced convection type solar

dryer

N.METIDJI, W.BADAOUI, R.SALEMI

The Solar Equipments Development Unit, BouIsmail, Algeria.

[email protected]

Abstract

Solar radiation is one of the oldest renewable energy used for drying. Its use has started since the dawn of mankind. It was mainly used for food preservation and also for drying other useful materials as cloths, construction materials; etc .Numerous dryers have been designed and developed in various parts of the world, yielding varying degrees of technical performance. Basically, there are four types of solar dryers;

(1) direct solar dryers, (2) indirect solar dryers, (3) mixed-mode dryers and (4) hybrid solar dryers. Solar drying is one of the processes that have found application in Algeria, because of the important quantities of solar irradiations that can be exploited in this country. Nevertheless, the experience of Algeria in solar drying is recent and limited to fruits drying, vegetables, medicinal and aromatic herbs. The aim of this work is to study dried tomatoes in a forced convection type solar dyer. To investigate the experimental performances of the solar dryer for tomatoes drying, 13 full scale experimental runs were conducted. Exhaustive research and development work have to be carried out in order to make solar drying of tomatoes economical and friendly to the environment.

Keywords: Solar dryers, Tomatoes drying, Forced convection solar dryer, Solar system,

Energy conversion


- 102-

Experimental study for the performance of a solar

distiller

Nassim BABA AHMED, Abderrahim BENMOUSSAT

Material and Environment research of LAEPO laboratory,

Abou Bekr BELKAÏD

University of Tlemcen, BP 230 –Chetouan university pole –13000

–Tlemcen – ALGERIA.

[email protected]

Abstract

This article describes the experimental results obtained by the solar distiller by specifying the radiative properties of materials/material, the analysis of various types of losses/breakdown/loss in the system and the establishment of the energy assessment of the system being the main questions to consider. The experiment was undertaken in Tlemcen - Algeria by working out a solar distiller in order to measure the various temperatures of the system. Salt was added to study the negotiable effect of the salinity of water on solar distillation and it is noted that the production of distilled water decreases with salinity. Our distiller is forwarded to a constant global solar flow. Experimental results obtained in heat transfer of natural convection in the pure and simultaneous heat and mass transfer, proven that these phenomena are in the boundary layer. This enabled us to admit that the existence of a stagnant zone inside of distiller is called the “buffer zones”.

Keywords: Solar energy, thermal conversion, solar distillation, condensation, evaporation


- 103-

Study of heat transfer in an inclined triangular

cavity filled with a Cu–water nanofluid

Issam REZAIGUIA, Mahfoud KADJA, Ridha MABROUK, Noureddine

BELGHAR

Laboratoire d’Energétique Appliquée et de Pollution, Université Mentouri-

Constantine, Algeria.

[email protected]

Abstract

This paper discusses the results of a study related to natural convection cooling of a heat source located on the bottom wall of an inclined isosceles triangular enclosure filled with a Cu water-nanofluid. The right and left walls of the enclosure are both maintained cold at constant equal temperatures, while the remaining parts of the bottom wall are insulated. The study has been carried out for a Rayleigh number in

the range 〖10〗^4≤Ra≤〖10〗^6 , for a heat source length in the range 0.2≤ε≤0.8,

for a solid volume fraction in the range 0≤ϕ≤0.06 and for an inclination angle in the

range 0^0≤δ≤〖45〗^0 . Results are presented in the form of streamline contours,

isotherms, maximum temperature at the heat source surface and average Nusselt number. It is noticed that the addition of Cu nanoparticles enhances the heat transfer rate and therefore cooling effectiveness for all values of Rayleigh number, especially at low values of Ra. The effect of the inclination angle becomes more noticeable as one increases the value of Ra. For high Rayleigh numbers, a critical value for the

inclination angle of δ=〖15〗^0 is found for which the heat source maximum

temperature is highest.

Keywords: natural convection ; nanofluids ; triangular cavity ; inclination angle


- 104-

Numerical study of a fixed bed drying at high-

temperature of alumina AL2O3

Aymen SDAYRIA1, Souad MESSAI

1, Jalila SGHAIER

2, Afif El CAFSI

1

1Laboratoire d’Energétique et des Transferts Thermiques et Massique LETTM.

FST. Université de Tunis El-Manar. 2Unité de Thermique et Thermodynamique des Procédés Industriels, Ecole

Nationale d’Ingénieurs de Monastir, Avenue Ibn El Jazzar 5019 Monastir-

[email protected]

Abstract

In this paper, a mathematical model based on heat and mass transfer mechanisms between the air and the granular medium was developed in order to simulate the fixed bed drying process of alumina particles conducted at high-temperature. To describe the coupled heat and mass transfer in such an environment, a mathematical model with double porosity is developed with a double scaling; this double scaling theory is based on making medium according toWhitaker [1]assuming that the hypothesis of local thermal equilibrium is no longer valid. So a two-temperature model was presented. The mass transfer described by a kinetics

numerical drying was deduced from the work of J. Sghaier [2] and validated with experimental results of J. Hager [3] and S. Messai [4]. A test of sensibility was presented to take notice of some parameters like the diameter of particle and the air velocity on the drying kinetics. A comparison between the superheated steam and humid air drying processes has been demonstrated in the case of drying of alumina particles. The numerical results are confronted with experimental results carried out by S. Messai [4] and J.Hajer [3].

Keywords: Alumina, packed bed, numerical simulation, drying, heat and mass transfer


- 105-

Analysis of heat and mass transfer in a co-courant

flow membrane -based enthalpy exchanger

Ramzi SEBAI, Ridha CHOUIKH, Amanallah GUIZANI

Centre de Recherche En Technologies de l’Energie

BP95 Hamamlinf 2050 Tunisia.

[email protected]

Abstract

The present work investigates the heat and mass transfer mechanisms in a co-courant flow parallel plate membrane based enthalpy exchanger. The three dimensional model which accounts simultaneously for heat and mass transfer in the membrane and the channels with balanced and unbalanced flow. The results are compared to the available data and the agreement is satisfactory. The effect of operating parameters such aspect ratios of the rectangular ducts, volume flow rates andthe temperature differencesare also investigated. The results show that for a fixed channel height, with as the fan power increases, the heat transfer rate initially increases, after reaching a maximum velocity in the channel.

Keywords: Heat transfer; Mass transfer; Membranes; Co-courant flow.


- 106-

Thermal study of mixed convection with viscous

dissipation and pressure work

KHADRAOUI Mounir1, SAMMOUDA Habib

2, BEN NACER Rachid

1Ecole Supérieure des Sciences et de Technologie, Rue Amin ElAbbassi, 4011

Hammam Sousse (Tunisie). 2LEEVAM, Université de Cergy-Pontoise, 2 Avenue Adolphe Chauvin BP222,

95302 Cergy Pontoise (France).

[email protected]

Abstract

This paper, we present a numerical investigation of the mixed convection for a fluid in annular space between two coaxial vertical cylinders. The vertical sides are kept isothermal at different temperatures, while the horizontal sides are insulate. Two sample fluids are considered: a gas and a highly viscous liquid. The effects of viscous dissipation and pressure work are taken into account, the governing balance

equations are solved numerically by employing a Galerkin finite element method. In the frame work of the Oberbeck–Boussinesq approximation, a comparison is made between three different models: (A) pressure work and viscous dissipation are included; (B) viscous dissipation is included only; (C) both pressure work and viscous dissipation are neglected. The influence of the temperature on the structure of the dynamic and thermal fields is examined.

Keywords: Heat transfer ; viscous dissipation; Laminar flow; Pressure work; Numerical

solution


- 107-

Thermal performance study of a solar desalination

unit

Khalifa ZHANI1 and Habib BEN BACHA

2

1Laboratoire des Systèmes Electro-Mècaniques (LASEM), National

Engineering School of Sfax, Sfax University, Tunisia. 2College of Engineering in Alkharj, King Saud University, BP 655-11946

Kingdom of Saudi Arabia.

[email protected]

Abstract

In view of the growing global demand for energy and water, both for potable use and for irrigation, the coupling of renewable energy sources, such as solar energy, with desalination units would generate a sustainable source of fresh water as well as energy. This coupling is highly valued as it limits and reduces the consumption of fossil fuel and the production of CO2 emissions. A new generation of water desalination installationby solar energyusing a multiple effect humidification process and called SMCEC technique (Solar Multiple Condensation Evaporation Cycle) is presented in this paper. The good quality of distilled water obtained by

this new concept favours its use for producing water for drinking and irrigation. The purpose of this work is to present the design, the operation principle, the modelling, and the thermal performance of this kind of installation exposed to a variation of the control parameters.

Keywords: Solar energy, water desalination, steady state, modeling, GOR.


- 108-

Techno economic performances of a dry cooling

solar tower power plant under Algerian climate

Mohamed ABBAS, Zoubir BELGROUN and Nachida KASBADJI MERZOUK

Unité de Développement des Equipements Solaires, UDES.

[email protected]

Abstract

Algeria is very rich in solar energy resources and possesses large wasteland areas in the Sahara that represent 80% of the total area. These rural needs represent a potential market for renewable energy technologies. Currently, Algeria envisages the substitution of the fossil energies by the renewable energy, especially solar energy. In this context, the government of Algeria has committed itself to develop solar energy (photovoltaic, concentrating solar power) asits largest renewableenergy source; to cover 20% of the national electricity needs by 2030 with renewable energy (solar and wind energy). All these indicators make Algeria an ideal country for the implementation of the Concentrating Solar Thermal Technologies (CSTT). In this purpose, this article present a techno economic assessment of a100 MW of solar tower power plant for electricity generation located in one typical site of the Saharan environment of Algeria (Tamanrasset). The NREL‟s SAM software (Solar Advisor Model) is used to evaluate the monthly energy production, annual energy output, Levelized cost of energy (LCOE) and the Net Present Value (NPV) for this study.

Keywords: Solar energy, solar tower, techno-economic, SAM, Algeria


- 110-

Parametric studies on the thermal solar membrane

distillation equipped with a helically coiled fibers

Adel ZRELLI, Béchir CHAOUACHI, Slimane GABSI

Environmental, Catalysis and Process Analysis Research Unity, National

Engineering School of Gabes. University of Gabes, Omar Ibn. ElKhattab St.

6029 Gabes, Tunisia.

[email protected]

Abstract

This work concern the study of some parameters of vacuum membrane distillation installation coupled with solar energy. The used membrane module, in our case, is composed of two hollow fibers membrane wound in helically coiled shape. These fibers are placed in parabolic through concentrator absorber. Four parameters are studied in this paper in order to their optimization. After the establishment of the

equations system, which is composed of two dimensional Navier-Stokes equations, theresolution was done with the finite element method. The results show that the optimized values of fiber geometric configuration are for the coil pitch is 3.22 cm, for the fiber diameter is 6 mm and 95.7 mm for the coil radius. The value of the optimized absorber diameter is 14 cm. For this configuration case, the permeate flow rate is equal as 18.6 10-5 kg/s.

Keywords: Vacuum membrane distillation, Solar energy, Helical fiber, Parametric studies


- 111-

Numerical study of transient double–diffusive

natural convection in a salt–gradient solar pond

Ridha BOUDHIAF, Ali Ben MOUSSA and Mounir BACCAR

Research Unit of Computational Fluid Dynamics and Transfer Phenomena

(CFDTP)

Department of Mechanical Engineers, National Engineering School of Sfax,

Street of Soukra, Km 3.5, B.P. 1173, 3038, Sfax, Tunisia.

[email protected]

Abstract

A numerical simulation of the double–diffusive natural convection is developed in a two–dimensional salt–gradient solar pond by solving the governing equations of continuity, momentum, thermal energy and mass transfer in transient regime. The body of the simulated pond is a rectangular enclosure of height H and length L where an artificial salinity gradient is created in order to prevent convective motions induced by solar radiation absorption. The enclosure isfilled with waterand constituted by three different salinity zones. The bottom of the enclosure is painted in black and the free–surface is subjected to heat losses by convection, evaporation and radiation while the two vertical walls are thermally insulated and impermeable. The bottom and the free–surface of the enclosure are also impermeable. The numerical results are reported for the effect of salinity gradient on the transient evolution of temperature, concentration and flow fields during the storage of solar energy as thermal energy in a solar pond. The effect of salinity gradient on the evolution of average temperature and concentration profiles is also analyzed. This study shows the importance of the salinity gradient in the maintaining of high temperature in the bottom of the solar pond, and in the reduction of heat and mass transfer phenomena in the non–convective zone (NCZ).

Keywords: Storage of thermal energy; Transient double–diffusive convection; Salinity–

gradient; Solar radiation absorption; Numerical study.


- 113-

Numerical study of mixed convection in tilted lid

driven cavities at low reynolds numbers

Noura BEN MANSOUR, Nader BEN-CHEIKH, Brahim BEN-BEYA, Taieb LILI

Laboratory of Fluid Dynamics, Physics Department, Faculty

of Sciences of Tunis,

Campus Universitaire, 2092 El-Manar II, Tunisia.

[email protected]

Abstract

In this study, the mixed convective heat transfer in a lid driven cubic cavity at different inclination angles is investigated numerically. The top moving lid of the cavity is maintained at constant temperature, while the vertical walls are thermally insulated. The Reynolds number is fixed at Re=100, while the Richardson number is varied from 0.001 to 10. Parametric studies of different inclination angles of the

enclosure on the fluid flow and heat transfer have been performed. The enclosure tilt or inclination angle is varied from 0° to 180°. It is shown that for a considered Richardson number, there is an optimal inclination angle for which the heat transfer rate through active walls is maximum.

Keywords: Mixed convection, Richardson number, lid-driven cavity, tilted enclosure.


- 114-

Comparison of different configurations to improve

the liquid film evaporation in the vertical annulus

Rym BEN RADHIA1, Souad HARMAND

2, Jean Pierre CORRIOU

3,

Sadok BEN JABRALLAH4

1Laboratoire d’énergétique et des transferts thermique et massique, Campus

Universitaire, 1060 Tunis. 2Université de Lille Nord de France, F-59000 Lille UVHC/TEMPO, F-59313

Valenciennes Cedex. 3LRGP-CNRS-ENSIC, Université de Lorraine, 1, rue Grandville B.

[email protected]

Abstract

Mixed convection heat and mass transfer with film evaporation into the upward laminar stream of air in vertical annulus was studied numerically. On the outer face of the inner cylinder, a thin film of water falls. The second cylinder is assumed insulated and dry. A counter current flow of air is blown between the two vertical cylinders. Three configurations are considered in this study which can based on solar energy to

evaporate the liquid film. The first consists in applying a heat flux density to the inner cylinder. The second and the third deal respectively with a preheated air flow and a preheated water film at the inlet of the annulus. In order to enhance the evaporation, the comparison between the three configurations is performed. It was demonstrated that the third configuration with preheating of liquid film is the best technique to obtain

a significant evaporated average mass flux density and a maximum efficiency. The first configuration occupies the second place to have an evaporated average mass flux density larger than the second configuration.

Keywords: Evaporation, liquid film, efficiency, annulus.


- 115-

Design of a simple solar still

HALFAOUI Wafa1, KHALFA Leila

1, HIDOURI Nejib

2

and BEN BRAHIM Ammar3

1Research Unit: Thermodynamic Applied to Machines

99/UR/11-21 ENIG -Tunisia. 2Research Unit: Thermodynamic Applied to Machines

99/UR/11-21 ENIG -Tunisia. 3Research Unit: Thermodynamic Applied to Machines

99/UR/11-21 ENIG -Tunisia.

[email protected]

Abstract

Solar distillation seems to be a promising method and alternative way for supplying small communities in remote areas and islands with water. In fact, it has been reported that for such places, solar distillation could be the most favorable way for water supply.

The present study aims to model a simple solar still. So a mathematical modeling has been carried out aided by some basic and simplified hypotheses, according to overallthermal balances andappropriate heat and mass coefficients. To test the performance of the still, it is necessary to evaluate some important parameters affecting the system productivity like the water depth in the basin and glass thickness.

Resolution of equations, based on program software „MATLAB‟, has shown that a better efficiency is obtained at a lowest thickness of the solution to be distilled and a low glass thickness.

Keywords: Solar, still, performance, model, software


- 116-

Large eddy simulation of turbulent flow in

Rayleigh-Bénard configuration

Fayçal HAMMAMI, Nader BEN-CHEIKH, Brahim BEN-BEYA, Taieb LILI

Laboratory of Fluid Dynamics, Physics Department, Faculty of Science of

Tunis,Campus Universitaire, 2092 El-Manar II, Tunisia.

[email protected]

Abstract

This work undertakes a numerical study of turbulent incompressible flows in Rayleigh-Benard configurations using Large Eddy Simulation and two sub-grid scale models, i.e., the WALE (Wall Adapting Local Eddy-viscosity) model and the corresponding dynamic sub-grid model (DSGS). In the process of using DSGS, an optimal value of constant of the WALE model was determined for the envisaged Rayleigh number (Ra=6.3.105). The computed numerical results (on a relatively coarse grid) showed good agreement with those Direct Numerical Simulation (DNS) results found in the literature. It is observed that the profiles obtained are highly dependent on the time interval over which the statistics are made (equivalent to the Interval of Statistical Analysis (ISA)).

Keywords: Turbulent natural convection, Finite volume method, Large eddy simulation.


- 117-

Numerical simulation of the flow and heat transfer

around a rotating cylinder

Rafik BOUAKKAZ1, Kamel TALBI

1, Yacine KHELLILI

1, Farid SALHI

2

1Laboratoire d'Energétique Appliquée et de Pollution, département de Génie

mécanique,Université des Frères Mentouri, Constantine, Algérie. 2 Département de Génie Mécanique, université Mouloud Mammeri Tizi ouzou.

[email protected]

Abstract

In this work, the numerical study of heat transfer and air flow around an unconfined heated rotating circular cylinder is investigated for varying rotation rates (α = 0-6) in the Reynolds number range of 20-200. The numerical calculations are carried out by using a finite volume method based commercial computational fluid dynamics solver FLUENT. The successive changes in the flow pattern are studied as a function of the rotation rate. Suppression of vortex shedding occurs as the rotation rate increases (α >2). A second kind of instability appears for higher rotation speed where a series of counter-clockwise vortices is shed in the upper shear layer. The rotation attenuates the secondary instability and increases the critical Reynolds number for the appearance of this instability. Besides, transient (Strouhal number) and time-averaged (Nusselt number) results are obtained and compared with the literature data. A good agreement is obtained for both the local and averaged predicted values compared with previously obtained experimental and numerical observations.

Keywords: Air flow, dynamics, computing,


- 118-

Numerical study of natural convection from

rectangular and semi-circular cavity: effect of shape

and angle of inclination

Sonia BEZI, Nader BEN-CHEIKH, Brahim BEN-BEYA and Taieb LILI

Laboratory of Fluid Dynamics, Physics Department, Faculty of Sciences of

Tunis,

Campus Universitaire, 2092 El-Manar II, Tunisia.

[email protected]

Abstract

In order to identify the influence of shape and inclination on the flow structure and the heat transfer, numerical simulations are carried out on two different geometries partially heated: rectangular and semi-circular cavity. For these two flow configurations, the same aspect ratio and a Prandtl number are considered. The present numerical method is based on the Navier-Stokes equations and energy equation. The finite volume scheme and the projection method are adopted to solve these transport equations. Comparisons with (experimental or numerical) results for natural convection heat transfer from a horizontal cylinder enclosed in a rectangular cavity are first presented to validate the code. The predicted Nusselt Number was in good agreement with the previous experimental results. After validation, the influence of the inclination and the geometry of the cavity on the heat transfer are then investigated where Rayleigh number changes from 103 to 106. For both rectangular and semi-circular cavities, the results show the height impact of the angle of inclination on the Nusselt number, streamlines and isotherms.

Keywords: numerical simulation, inclined cavity, natural convection, heat transfer.


- 119-

Energetic optimization of flat plate solar collectors

in transient behavior

HAMED Mouna, FELLAH Ali and BEN BRAHIM Ammar

University of Gabes, Engineers National School,

Applied Thermodynamic Research Unit (UR:11ES80),

6072 Gabes, Tunisia.

[email protected]

Abstract

In this paper, an energetic optimization of flat plate solar collectors is developed to determine the optimal performance and design parameters of these solar to thermal energy conversion systems. The collector is used to supply hot water. It consists of three main components, namely a transparent cover, an absorber and a transfer fluid. A transient simulation method has been developed to characterize the dynamic behavior. The model was established regarding the energy balance analysis. A set of equations representing the model was simultaneously solved. The results are used to investigate the effect of various parameters on the performance of the collector such as outlet water temperature. The overall methodology has been developed on environmental data which are characteristic of the city of Gabes in Tunisia.

Keywords: Flat plate solar collector, thermal performance, dynamic simulation.


- 120-

Numerical study of a Photovoltaic thermal (PV/T)

collector

REJEB Oussama, DHAOU Mohamed Houcine, JEMNI Abedelmajid

Laboratoire d’Etudes des Systèmes Thermiques et Energétique, Rue Ibn

Eljazzar, Ecole

Nationale d’Ingénieurs de Monastir, Université de Monastir, Monastir 5019,

Tunisia.

[email protected]

Abstract

In this paper a mathematical model has been developed to evaluate the thermal and electrical power of photovoltaic thermal (PV/T) collector. A mathematical model has been established and solved numerically by the finite volume method. The established model is used to study the effect of the packing factor of the photovoltaic thermal collector.

Keywords: photovoltaic thermal (PV/T), thermal power, electrical power


- 121-

Appraisal of the effect of solar passive techniques on

the thermal performance of a glazed building in

Tunisia

Meriem SOUSSI , Moncef Balghouthi, Amenallah GUIZANI

Research and Technology Center of Energy (CRTEn)- B.P. 95, 2050. Hammam

Lif, Tunisia.

[email protected]

Abstract

Energy efficient coatings constitute a powerful passive solar strategy that favours indoor lighting, heat gain and inside thermal comfort as well as a pleasing aesthetics. For this reason, the thermal performance of a solar-cooled building including several windows has been studied in this paper using different types of windows. Several simulations have been carried out using the Transient Simulation program TRNSYS to assess four windows glass configurations: double-glazed, triple-glazed, low-emissive coatings and low-emissive-Argon coatings. The numerical modelling pointed out that the low-emissive Argon coatings are the most efficient given that they guarantee the most important savings in energy requirements compared to the other glazings. The attenuation in total heating requirements reaches 65% whereas the cooling demands diminution is about 8%. In the second part of this paper, we proposed the use of internal curtains and the implementation of 1,5m solar overhangs, shading every window of the building in order to avoid the overheating effect caused by large glazed windows during the hot season. The numerical simulations showed a decrease of the total cooling requirements of 21,5% and a raise in heating demands that reaches 65% compared to the existing building requirements.

Keywords: Windows, passive, thermal performance, building, curtains, overhangs.


- 122-

Performance analysis of single stage LiBr/H2O and

LiCl/ H2O solar absorption heat transformer

GOMRI Rabah

Department of «Génie Climatique» - Faculty of Engineering,

Université Mentouri, Constantine - 25000 Constantine, Algeria.

[email protected]

Abstract

This paper concerns the comparison of solar absorption heat transformers systems. A heat transformer is a device to raise the temperature of heat obtained from a source and deliver it to a higher temperature heat sink. A method is presented for predicting the performance of solar LiBr/H2O and LiCl/H2O absorption heat transformers, which receive solar heat at an intermediate-temperature level, reject a part of it in the ambient at a low-temperature level and deliver the remaining useful heat at a high-temperature level. Simple relations are derived, which define the thermodynamic cycle of heat transformer and allow calculation of characteristic temperatures and heat quantities exchanged in terms of the main parameters of the two systems.The maximum coefficient of performance of the two systems is termined. The results obtained here may provide some theoretical bases for the optimal design of the solar absorption heat transformers.

Keywords: Performance, Heat-transformer, Absorption cycle, Solar energy, LiBr/H2O,

LiCl//H2O


- 123-

Experimental and numerical investigation of a solar

water heater with latent storage cavity

Salwa BOUADILA1, Mouhamed Mehdi OUESLATI

2, Mehdi FTEÏTI

3,

Amenallah GUIZANI1 ,Abdelhamid FARHAT

1

1 The Thermal Processes Laboratory of The Research and Technology Center of

Energy, CRTEn Tunisia. 2The Laboratory of Wind Power Control and Energy Valorization of Waste,

CRTEn Tunisia. 3 The Laboratory Studies of Thermal and Energy Systems, ENIM Monastir

[email protected]

Abstract

The energy production provided by a heat excess or discontinuous source (solar, waste heat...) involve the utilization of a thermal storage systems. The study includes two parts. The first concerns a numerical analysis of a latent-heat thermal energy storage unit. The element of storage is a rectangular closed cavity filled with a phase change material (PCM) initially at the solid state. At t=0 a heat flux is applied through one of the vertical walls of the cavity. Another one, concerns an experimental study treats an integrated solar latent storage collector ISLSC. The variation of the PCM temperature in the center of the ISLSC are tested and validated with a numerical model.

Keywords: Latent heat storage; packed bed solar air heaters; thermal efficiency; exergy

efficiency


- 124-

Modeling and experiment of a solar air collector

intended for the drying of leaves product.

TOUATI Boumediene, Kerroumi Noreddine, SAAD Amel, ABDENBI Asma

Energy Laboratory in Arid Zones (ENERGARID), Equip solar resource and its

applications, University of Bechar, Bechar, Algeria.

[email protected]

Abstract

Our work has consisted of the numerical modeling and experimental study of an air solar collector with simple circulation in forced convection. The modelization is based on the resolution of the equations of transfer between the elements of the collector such as the absorbing plate, the transparent cover and the air inside the collector. The code of calculation developed for the solution of these equations is in Matlab by using function ODE45.The numerical simulation enabled us to determine the profiles of temperature of all elements of collector and its efficiency. In the experimental part, we could realize and to test in the Unit of Research of Renewable Energies in Saharan Medium (URER/MS) of Adrar, an air solar collector of simple circulation in forced convection. The measured temperatures of the absorber, the glazing and the air inside the collector are used for the chock of our calculation code.

Keywords: Modeling, Experiment, Collector, Drying, leaves product


- 125-

Performance of an improved Trombe wall: An

experimental study

DIMASSI Narjes, DEHMANI Leila

Laboratoire des Procédés Thermiques, Centre de Recherche et des Technologies

de l’Energie, Technopole de Borj-Cédria, BP 95 Hammam-Lif 2050, Tunisia.

[email protected]

Abstract

In this paper, the energy performance of an improved Trombe wall of a model test room has been carried out experimentally. The case study is conducted in Borj Cedria, Tunisia where there is always heating requirements. Here, we propose an improved Trombe wall whose absorber wall is covered with a thin black copper panel backed rather than simply painted black wall. The proposed idea would offer improved thermal performance, especially for natural convection. The results show that the improved Trombe wall design gives an increase for both conductive and convective flux. Consequently, the improved Trombe wall will work more effectively than the classical Trombe wall system in utilizing solar energy for the example of test room.

Keywords: Improved Trombe wall, thermal performance, convection, conduction


- 127-

Numerical simulation of radiative heat transfer in

non gray media using the CVFEM

Hanene BELHAJ ALI, Hajer GRISSA, Faouzi ASKRI, Sassi Ben NASRALLAH

Université de Monastir, Ecole Nationale d’Ingénieurs de Monastir.

Laboratoire d’Etudes des Systèmes Thermiques et Energétiques (LESTE).

Rue Ibn Eljazzar, 5019 Monastir, Tunisia.

[email protected]

Abstract

The control volume finite element method (CVFEM) is coupled with the weighted sum of gray gases model (WSGGM) to simulate radiative heat transfer in a participating non gray media. To validate this hybrid method, two particular test problems of one dimensional and two-dimensional rectangular enclosures, containing a single gas composition (water vapor or carbon dioxide) and a H2O-CO2-N2 gas mixture, are examined. The obtained results are compared successfully with DOM-LBLM, DOM-SNBM and RTM-SNBM solutions and they confirm that the proposed method (CVFEM-WSGGM) is recommended for applications.

Keywords: CVFEM, Radiative heat transfer, WSGGM, non gray media


- 128-

Design of a micro grooved receiver surface for a

solar powered stirling engine generator

Md. Didarul Islam 1 and Kunwar Apoorva Singh

2

1Assistant Professor, Department of Mechanical Engineering, The Petroleum

Institute, Abu Dhabi, UAE. 2 B. Tech., Department of Mechanical Engineering, Indian Institute of

Technology Kanpur, Kanpur, India.

[email protected]

Abstract

Renewable energy technology particularly solar energy applications are of great interest. Amongst Multiple solar energy applications exists the generation of electricity using a Stirling engine. Two main components of solar powered Stirling engine are the receiver which absorbs solar insolation and the generator which converts it into electricity. In current heat pipe technologies, receiver surface uses a sintered metal mesh, metal powder, or metal felt. At high temperatures, under concentrated solar energy, the solar receiver surface "dry out" and tend to separate the sintered powder from the pip, resulting into melting of the heat pipe walls.

Our objective is to design a solid micro-grooved receiver surface that increases surface area to provide an effective heat transfer to avoid this dry out and wick separation. In this paper, micro grooves are designed (width = 70.22 μm, depth= 31.23μm, pitch = 70.22 μm) and simulated using MATLAB and MAPLE.

Keywords: Solar Power, Stirling Engine, Microgrooves


- 129-

Thermal Analysis Of A Solar Still Coupled With A

Separated Condenser Functioning In Natural

Convection

H. Moungar1, A. Azzi

2, M. Ben hammou

1

1Research unit in Renewable energies in Saharan Medium B.P. 478, ADRAR.

ALGERIA 2Mechanical Department of Engineering of University ABOU BEKR

BELKAID TLEMCEN

[email protected]

Abstract

Solar distillation constitutes one of the processes, which will supply the potable water to villages and the small cities, with limited consumption. Nevertheless the efficiency of this process remains extremely limited. The purpose of the present work consists to coupling a solar still with a separated condenser. A solar still which allows to have a production higher than that of a plane distiller and whose thermal losses are less low is used. In this study the heat balance of the system are established. Then the temperatures on the level of each part of the system are calculated. The system of equations governing the operation of this system is solved in MATLAB with the RUNGE-KUTTA-FEHLBERG, iterative method‟s. The influence of many parameters in particular the irradiation and temperature of water, the speed of the wind, and the water depth, on the operating characteristic will be also presented.

Keywords: solar still, collector, production, efficiency

- 130-


- 131-

Energy Management and

Storage

‘EMS’

- 132-

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-EMS-69/O

- 137-

Fuzzy energy management of an off-grid

PV/Battery system

Imene YAHYAOUI 1,2, Souhir SALLEM2, M.B.A KAMMOUN2 and Fernando

TADEO1

1Industrial Engineering School, University of Valladolid, Spain. 2Unité de

Commande de Machines et Réseaux de Puissance CMERP-ENIS, University of

Sfax, Tunisia.

[email protected]

Abstract

This paper presents a control methodology to take the decision on switching between components in a photovoltaic installation with mixed energy sources: a photovoltaic panel and a battery. The decision is made by fuzzy rules on the basis of the Photovoltaic Panel Generation forecast, the required power for the load, and by considering the correct operation of the battery. The algorithm aims to ensure the autonomy of the system by controlling a switching unit which links the system components with respect to multi-objective management criteria. Some tests of the algorithm are shown in order to demonstrate that the approach ensures the autonomy of the system and respects battery safety.

Keywords: photovoltaic energy, management, fuzzy logic, battery safety, system

autonomy

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-EMS-76/P

- 138-

Dose rate calculation in a PMMA dosimeter

E. JEMII, M. MAZOUZ, L. GHEDIRA

Département de physique, Faculté des sciences de Monastir, Université de

Monastir, Monastir 5000, Tunisia.

[email protected]

Abstract

Dose rates determination using a PMMA dosimeters, placed in the vicinity of the Tunisian 60Co gamma ray irradiator, have been achieved, by modelling this irradiator with a single pencil of equal height and equal activity. The obtained results are in very good agreement with a simulation using a GEANT4 code.

Keywords: 60Co gamma irradiator, Dose rate, GEANT4, PMMA dosimeter


- 139-

Effect of inter-cooling on the performance of the

solar energy assisted hybrid air conditioning system

(SEAHACS) with one-rotor six-stage rotary

desiccant cooling system

Ali ELZAHABY, Abdelnaby KABEEL, Mohamed MAHGOUB, Mohamed

ABDELGAIED

Mechanical power engineering department, Faculty of engineering, Tanta

University, Egypt.

[email protected]

Abstract

In this study, a mathematical model for predicting the performance of solar energy assisted hybrid air conditioning system (SEAHACS) was considered. The desiccant wheels used honeycombed silica gel–haloids composite desiccant wheel, one-rotor six-stage rotary desiccant cooling system, in which two-stage dehumidification process, two-stage pre-cooling process and two-stage regeneration process are realized by only one wheel. Three air streams are involved in the present system. The mathematical model has been validated with the experimental data. As the key operating and design parameter, the range of process air inlet temperature from 27.5 – 45 °C, range of humidity ratio of the inlet process air from 9 to 21 g/kg, process air inlet velocity from 1.5 – 5.5 m/s have been examined for a range of rotation speed from 6 -20 rev/h. the optimization of this parameters is conducted based on the moisture removal capacity D, relative moisture removal capacity, dehumidification coefficient of performance, thermal coefficient of performance, and supply air temperature and humidity ratio. At last, the influences of these main parameters on optimal rotation speed are discussed.

Keywords: hybrid system, Air conditioning system, Optimization, modeling,


- 140-

Numerical Compression Between the Performances

of Solar Energy Assisted Hybrid Air Conditioning

System (SEAHACS) for Using One-Rotor Two,

Four, Six-Stage Rotary Desiccant Cooling System

Ali ELZAHABY, Abdelnaby KABEEL, Mohamed MAHGOUB, Mohamed

ABDELGAIED

Mechanical power engineering department, Faculty of engineering, Tanta

University, Egypt.

[email protected]

Abstract

A mathematical model for predicting the performance of solar energy assisted hybrid air conditioning system (SEAHACS). The desiccant wheels used honeycombed silica gel–haloids composite desiccant wheel, one-rotor two, four, six-stage rotary desiccant cooling system. The mathematical model has been validated with the experimental data. As the key operating and design parameter, the regeneration air inlet temperature constant at 95°C, the process and the regeneration air inlet velocity are constant and equal to 2.5 m/s, the process and regeneration humidity ratio are constant and equal to 15 g/kg, the process air inlet temperature change from 27.5°C to 45°C have been examined for the rotation speed of 12 rev/h. the optimization of this parameters is conducted based on the moisture removal capacity D, relative moisture removal capacity, dehumidification coefficient of performance and thermal coefficient of performance.

Keywords: Solar energy, hybrid system, Air conditioning system.


- 141-

Energy consumptions of lighting systems in the

terminal buildings in turkey and energy-saving

applications

Nilgun F. BAYRAKTAR, Emre KIYAK

Anadolu University.

[email protected]

Abstract

One of the most important problems that we face with today is global warming. Global warming which arises fundamentally from use of energy sources that damage to nature has threatened quality, habitats and cycle of life. As in many sectors, the transportation sector is one of sectors that consumes energy in high levels, brings about greenhouse gases emission, and contributes to global warming. Because of this, it is of greatly importance for energy consumption and sources of the so-called sector to be controlled, to be in nature-friendly operation. In scope of this paper terminal building which exists within the structure of air transport is dealt with. When systems in a building analyzes in terms of consumption of energy, the biggest share belongs to lighting system. Concordantly, lighting system of terminal building of Anadolu University Airport, İstanbul Sabiha Gokcen Airport and İzmir Adnan Menderes Airport are analyzed from the point of consumption and sources of energy in the scope of this research. Findings which are obtained propound advantages of use of nature energy sources and novel lighting technologies. Consequently, to pave the way for greener approaches analyzing the current situation is aimed in this research.

Keywords: Lighting system, terminal buildings, LED technology, energy saving,

renewable energy


- 142-

Energy management opportunities for productivity

enhancement in a medium scale manufacturing

industry in lagos

S. M. Abolarin, M. B. Shitta, C. D. Nna, C. A. Eguma, A. O. Kedo, A. Yussuff,

O. A. Babatunde, B. O. Onafeso, O. Adegbenro

National Centre for Energy Efficiency and Conservation, Faculty of

Engineering, University of Lagos, Akoka, Yaba Lagos.

[email protected]

Abstract

The survival of an industry is hinged on its ability to maximize resource inputs particularly energy input for production regardless of its source. An industry should put in place well-articulated energy management programmes and identify opportunities for reducing energy wastes in all facet of production. Manufacturing companies in Nigeria pay little or no attention to the benefits of energy efficiency and conservation which include energy savings, cost savings and environmental sustainability. This paper investigates Energy Management Opportunities in a medium scale manufacturing industry and presents information to management to aid its decision-making. The energy consumption (electricity and diesel) information for the year 2011 was obtained to complement data collected from walk-through and comprehensive audits. An estimated 125,181kWh of electricity and 33,415litres of diesel were consumed for the period representing 32% electricity and 68% diesel costs, which amounts to N7,130,000.00 ($44,562.50). Energy management opportunities identified include; replacing in-efficient drive belt on large motors with energy efficient cog belts, monitoring electrical loads to reduce peak demand, turning off equipment when not in use, replacing in-efficient lamps with energy saving lamps and installing bank of capacitors to increase power factor of the motors from 0.77 to 0.99. The opportunities reveal an annual net saving of N996,989.48 ($6,231.18), which is about 14% of the company‟s annual energy cost.

Keywords: Energy Management Opportunities, Energy Audit, Energy Efficiency and

Conservation, Energy Consumption


- 143-

Modeling of a gamma Stirling engine

Houda HACHEM1, Ramla GHEITH

1, Fethi ALOUI

2 and Sassi Ben

NASRALLAH1

1Laboratoire d’Etude des Systèmes Thermiques et Energétique, Ecole Nationale

d’Ingénieurs de Monastir, Rue Ibn El Jazzar,

5019 Monastir, Tunisie. 2 Université de Valenciennes et du Hainaut-Cambrésis, ENSIAME, Lab.

TEMPO - EA 4542, DF2T, Le Mont Houy 5931

[email protected]

Abstract

Actually, the lack of appropriate thermodynamic design tools is the major impediment for the commercialization of the Stirling engine.

This work aims at developing a numerical model for predicting the performances of a kinematic gamma Stirling engine. Referring to the classical quasi- stationary model, a simulation program developed on MATLAB software was developed. It allowed calculating the performance of a Stirling engine in terms of brake power and thermal efficiency. After consideration of the hypothesis of semi real gas working fluid, the obtained results are even far from experimental ones which led consider the heat losses in the different compartments of Stirling engine. A second numerical program was developed considering the thermal losses in the Stirling engine. The results obtained by the final model are close to the experimental ones.

Keywords: Stirling Engine, Semi-real gas, Thermal losses, Regenerator efficiency, Brake

power, Initial load pressure


- 144-

Investigation of the rutting performance of hot and

warm asphaltic concretes: experimental and

stochastic approaches

Anissa EDDHAHAK-OUNI1

Arts et Métiers ParisTech, Ecole Spéciale des Travaux Publics, du bâtiment et

de l’industrie, Institut de recherche en constructibilité (ESTP/IRC) - 28, avenue

du Président Wilson - 94234 Cachan cedex - France. 1Université Paris Est, Institut de recherche en constructibilité - ESTP, F-94234,

Cachan, France

[email protected]

Abstract

This paper deals with an experimental study of hot and warm asphalt mixes respectively labeled HMA and WMA. A laboratory rutting experiment is performed by the use of the French rutting tester device (FRT) in order to compare the rutting performance of both mixes. At the beginning, the mix design and the manufacture

of HMA and WMA are carried out in laboratory. Then, the rutting test is performed simultaneously on both hot and warm bituminous slabs so that the experimental configuration is appropriate for comparison. Given the experimental dispersion of the rutting test results, statistical information of the rut depth is gathered.

Accordingly, a stochastic approach is developed using the principle of maximum of entropy to describe the rut random variable by suitable probability density function. It was shown through the evaluation of the rut depth computed after 30 000 cycles that the hot asphalt exhibits a better rutting resistance than the warm asphalt. In addition, the estimated rut of the warm asphalt seems to be satisfactory and in a good correlation with the French specifications. Moreover, the probabilistic parametric analysis was useful to define confidence regions of the rut depth for the prediction of the rutting performance of both HMA and WMA.

Keywords: warm asphalt, energy saving, rutting, uncertainties, stochastic.


- 145-

Micro hydroelectric power in Sicily: the energy

production of early XIX sec. and the future

opportunities

Antonio GAGLIANO, Francesco NOCERA, Francesco PATANIA, Aldo

GALESI and Giuseppe BIUNDO

DII – Engineering – University of Catania.

[email protected]

Abstract

Hydropower currently over other renewable sources like wind, solar and biomass offers some not negligible benefits that generally include a lower cost of installation to equal installed capacity, higher reliability, higher energy production and more intensity and consistency over time.

Recent years have witnessed the rehabilitation of old small hydro plants, which previously were not economically feasible. In fact, nowadays, thanks to reduced fares offered to producers of renewable energy by the Feed-In Tariff (FIT) and the convention "energy selling", moreover thanks to the lower costs of the electronic and mechanical equipment which now have a lower impact on the overall budget in respect to the past, the hydropower plants can be an excellent source of economic gain also for micro and small size plants.

The article analyzes the technical and economic feasibility of the recovery and modernization of one of the oldest Sicilian ”micro hydro power plant built in 1900 in the Madonia area” and then abandoned and disused after the nationalization of the electric energy.

To this aim, the authors have revised the plant technical characteristics such as the nominal flow rate and head, the type of distribution, and also have calculated the economic profitability indicators, such as the Net Present Value (NPV).

Keywords: micro-hydro power, renewable energy, energy saving, historical plant


- 146-

Performance Testing of Mobile Phone Battery

O. A. Babatunde, B. O. Onafeso, O. Adegbenro

National Centre for Energy Efficiency and Conservation

(The Energy Commission of Nigeria) Faculty of Engineering, University of

Lagos, Akoka, Yaba Lagos, Nigeria.

[email protected]

Abstract

The advent of mobile telephony in Nigeria has brought a lot of development in the Nigerian business sector and inter-personal communication. However, the telephones have their challenges such as underperformance of some components, for example, the battery. Although replacement batteries are available in the market, under performance has always been the complaint of mobile phone users. This paper reports the empirical performance of a sample of mobile phone batteries. The performance tests carried out included determination of the battery capacity (Ahr rating), measurement of the battery‟s talk time, self-discharge test and ohm test. These tests were carried out using Cadex C8000 which is an advanced programmable battery testing system. From the results obtained, it is concluded that batteries which came along with newly purchased mobile phones perform better than replacement batteries obtained from mobile phone accessory shops. This confirms the claim of consumers on the underperformance of replacement batteries; therefore, there is need for standard in terms of mobile phone batteries imported into Nigerian market. This ensures better performance of mobile phone batteries, value for the money spent to purchase the batteries and reduction of the adverse environmental effects associated with the disposal of those batteries.

Keywords: Mobile phone, Battery capacity, Cadex C8000, Talk time, Performance.


- 147-

A real time energy management for electrical vehicle

using combination of rule-based and ECMS

Hanane HEMI1,2

, Jamel GHOUILI1 and Ahmed CHERITI

2

1University of Moncton.

2University of Quebec in Trois-Rivières.

[email protected]

Abstract

The studies on energy management and optimization are still at an early stage. The energy management of a fuel cell (FC) hybrid vehicle supported with a storing device such as batteries or supercapacitors, is a challenge. Indeed, whatever the followed route is, the available power must be distributed among the various components, in order to minimize hydrogen consumption and increase their life expectancy.

This article present a real-time energy management strategy for a fuel cell vehicle equipped with a battery. It is based on the “rule-based” method combined with the equivalent consumption minimization strategy “ECMS” .

This strategy is developed and simulated by using a dynamic model of the vehicle developed in the Matlab/Simulink environment.

Keywords: energy management, rule based, electric vehicle, battery, fuel cell


- 148-

Pressure-composition-isotherm behaviors of MgHx-

graphene composites by reactive mechanical

alloying

Kyeong-Il Kim1, Joong-Woo Ahn

2, Whan-Gi Kim

3, Hyunchul Ju

4,

Dong Min Kim5 and Tae-Whan.Hong

1

1Department of Materials Science and Engineering/Research Center for

Sustainable ECo-Devices and Materials (ReSEM), Korea National University of

Transportation, 50 Dae hak ro, Chungju, Chunbuk, Korea. 2Department of Interdisciplinary ECo Science, Sungshin

[email protected]

Abstract

In order to improve disadvantage of Mg hydride, a few studies were conducted for MgHx intermixed with carbon. And it shows that carbon and carbon allotropes have a beneficial effect on hydrogen sorption in Mg. The graphene is a kind of carbon allotropes which is easily to desorption reaction at low temperatures due to its reaction is exothermic. In this work, we are aimed at improving the operating temperature and slow reaction kinetics of the MgHx with addition of graphene powder. The MgHx-Graphene mixture has been prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and simultaneous thermo gravimetric (TG), differential scanning calorimetric (DSC) analysis. The hydrogenation behaviors were evaluated by using a sievert‟s type automatic pressure-composition-temperature (PCT) apparatus. From the characteristics of the absorption kinetics and curves observed the role of graphene as catalyst in hydrogen absorption. The effect of added amount of graphene has been shown operating temperature of dehydrogenation that reduced. And MgHx-5wt.% graphene composite evaluated 3.43wt.% hydrogen storage capacity which of volume were measured maximum at 573K.

Keywords: Hydrogen storage materials, Sorption kinetics, Metal hydride, MgHx-

graphene composite, Mechanical alloying


- 149-

Materials life cycle assessments and evaluations of

hydrogenation property on MgHx-BZY composites

by reactive mechanical alloying

Kyeong-Il Kim1, Joong Woo Ahn

2, Tae-Whan Hong

1

1 Department of Material Science and Engineering/Research Center of

Sustainable Eco-Devices and Materials (ReSEM), Korea National University of

Transportation, Daehak-ro 50, Chungju, Chungbuk, 380-702, Korea. 2 Department of Interdisciplinary ECo Science,

[email protected]

Abstract

Magnesium hydride that has a high hydrogen storage capacity of 7.6wt.% is suitable for use in a hydrogen storage alloy. BZY (BaZr0.8Y0.2O3-δ) composites that have high proton conductivity and high chemical stability are expected to exert a positive catalytic influence on the kinetics of hydrogenation behavior. A Material Life Cycle Assessment (MLCA) should be conducted for prospective products to solve real or potential environmental problems. Conducting a MLCA is also a process of identifying opportunities to improve the environment by evaluating the environmental impact of energy and resources. In the study, we prepared MgHx-BZY composites using Reactive Mechanical Alloying (RMA). BZY powder prepared by the sol-gel method and by calcinations treatment was added to the Mg hydride. An environmental impact assessment of the MgHx-BZY was carried out using MLCA software. PCI hydrogenation evaluation indicates that, in terms of storage capacity, MgHx-5wt.% BZY composites are a superior material to MgHx-10 wt.% BZY composites. However, kinetic testing indicates that, in terms of the hydrogenation rate, MgHx-5wt.% BZY composites are a superior material to MgHx-10 wt.% BZY composites. The MLCA indicates that, among evaluated composite materials, nitric acid has the greatest environmental impact.

Keywords: Magnesium hydride, BZY (BaZr0.8Y0.2O3-δ) composites, kinetics, Reactive

Mechanical Alloying (RMA), Material Life Cycle Assessment (MLCA)


- 151-

Energy saving design method of power transformer

optimization by ant colony algorithm

Taoufik ZOUAGHI1,2

, Motasser FOUZAÏ1

(1) Research Lab SICISI- Higher School of Sciences and Techniques

of Tunis ESSTT. (2)

Academy Fonduk Jadid, Tunis.

[email protected]

Abstract

This paper describes a new optimization method based on Ant colony Algorithm for the optimal choice of the number of turns in the primary winding, flux and current density in power transformers .The goal of the proposed Algorithm is to minimize the cost of the transformer. The advantage of this method for the designer is to have quick results without having to deal with all possible combinations to get the optimal design. The proposed optimization methodology has been implemented successfully to optimize the design of Power transformers and results have been compared with conventional design techniques.

Keywords: Energy Saving, Ant colony optimization (ACO), Power Transformer Design,

Power Transformer optimization


- 152-

Experimental study of gravity assisted heat pipe

charged with methanol

M.S. ELMOSBAHI 1, A.W.DAHMOUNI

2 and S. Ben NASRALLAH

3

1Laboratory of Thermal Process, Research and Technologies Center of Energy,

Ecoparck of Borj-Cedria , BP 95 Hammam lif 2050, Tunisia. 2Laboratory of Wind Energy Management and Waste Energy Recovery,

Research and Technologies Center of Energy, Ecoparck ofBorj-Cedria , BP 95

Hammam lif 2050, Tunisia. 3 Studies of Thermal and Energy Systems Laboratory, National Engineering

School of Monastir, Street Ibn El Jazzar, Monastir 5000, Tunisia

[email protected]

Abstract

This paper focuses on the experimental analysis of the thermal behavior of a simple gravity-assisted two-phase closed thermosyphon. Experiments were carried out to examine the effects of inclination angle, evaporator power input, liquid fill charge and insulation of the adiabatic zone. This device has three sections including evaporator, adiabatic and condenser. Fins were attached at the condenser cooled by axial fans and an electrical heater used for providing the required heat source at the evaporator. The temperature distribution across the heat pipe was measured and recorded using thermocouples. The results of an experimental investigation of the energy behaviour of this system employing a heat-pipe are presented.

Keywords: Thermosyphon, evaporator power input effect, inclination effect, liquid fill

charge


- 153-

Exergo-Economic Optimization of Enhanced

Finned tube Air-water Heat Exchanger

Lassaâd NDARI, Tahar KHIR, Ammar BEN BRAHIM

Applied Thermodynamic Laboratory, National Engineering School of Gabes,

Tunisia.

[email protected]

Abstract

A thermo-economic optimization of two air-water heat exchanger configurations of louver and wavy fins is developed. These heat exchangers are integrated in air conditioning systems using geothermal water for heating. The heat transfer coefficients and pressure drop are evaluated.

The exergetic loads are established. The total irreversibility rates generated through the heat exchangers are determined taking into consideration the temperature gradients and pressure drops. That permits to analyze the influence of the different conceptual parameters on the exergetic efficiency. The optimal conceptions leading to a minimum annual total cost is defined.

In order to analyze the influence of different operational and conceptual parameters on the energetic performances of the heat exchangers, a numerical simulation is developed for the two HX. This simulation is established for a heating load of 2 kW taking into consideration the properties of the geothermal water of the region of Gabes (Tunisia). The purpose of this study is to obtain the optimal conception of each HX giving the minimum total annual cost. The operational parameters of optimization are; tube diameter, fins thickness, fin pitch and frontal velocity of air…

The total irreversibility rate regenerated with the wavy conception present 50% of this regenerated by the louver fins configuration. Similarly, the first one give an exergetic yield three times more than the other HX. Finally, the total cost of the wavy fins HX present 0.82 of the louver one.

Keywords: Air-water heat exchanger, intensified fins, air-conditioning, geothermal water,

thermo-economic optimization, cost.


- 154-

Application of evolutionary algorithm for

triobjective optimization in traction chain

of the electric vehicles

Naourez Ben HADJ and Rafik NEJI

University of Sfax, ENIS, Tunisia.

[email protected]

Abstract

For Electric Vehicles (EVs), Weight and losses reduction are important factors not only in reducing the energy consumption and cost but also in increasing autonomy.This paper describes the application of the evolutionary algorithm for the multiobjective optimization in the traction chain (TC) of EVs. In this study, the optimisation algorithm is based on the Strength Pareto Evolutionary Algorithm (SPEA-II) and the fitness function is defined so as to minimize the electric vehicle cost (EVC), the electric vehicle weight (EVW) and the losses in the electric vehicle (EVL).

Also, in this study, different requirements are considered as constraints like the efficiency of the permanent magnets engine, the number of conductor in the slots, the winding temperature…

The simulation results show the effectiveness of the approach and reduction in EVC, EVW and EVL while ensuring that the electric vehicle performance is not sacrificed.

Keywords: Evolutionary, Optimization, vehicle, cost, losses


- 155-

Energy Storage on Porous Media Using Lattice

Boltzmann Method

AMAMI Bayçain, DHAHRI Hacen and MHIMID Abdallah

National School of Engineers, Monastir University, Monastir, Tunisia.

Laboratory of thermal and energy systems studies.

[email protected]

Abstract

A numerical study is reported to investigate the energy storage in porous medium using Lattice Boltzmann Method (LBM). The channel was filled with a homogenous, isotropic and saturated porous medium with insulated walls. The flow is governed by the Darcy-Brinkman-Lapwood-Forchheimer modified model (DBLF). We assumed that the fluid phase and the solid phase are in local thermal equilibrium and viscous effects are tacked into consideration. A comprehensive analysis of the influence of the Darcy number and the Eckert number on temperature distribution and stored energy are investigated throughout this work.

Keywords: Thermal energy storage, porous media, Lattice Boltzmann Method, viscous

dissipation


- 157-

Economic and Fiscal Policy Analysis on Geothermal

Power Plant in Indonesia

Farizal

Department of Industrial Engineering. Universitas Indonesia.

Depok, 16424, Indonesia.

[email protected]

Abstract

Indonesia has launched her first 10,000 MWe crash program of coal-fired power plants (CPPs) and her second 10,000 MWe crash program which mainly composed of geothermal power plants (GPPs). This paper assesses GPP attractiveness from the investor standpoint through evaluating its production costs and the application of government incentives and taxes. Clean development mechanism (CDM) is also taken into consideration. The results show that under the current electricity selling price of 9.7 US¢/KWh implementing tax subsidies and incentive improve GPP attractiveness. It gives IRR of 16.02%. Incorporating CDM to the existing tax subsidies and incentive improve IRR by 2.70% more. Under this scenario the IRR is 18.72%.

Keywords: Geothermal electricity price, fiscal policy and incentives, clean energy, IRR


- 158-

Vector Control of an Induction Motor for

Photovoltaic Pumping

Imene YAHYAOUI 1,2

, Souhir SALLEM 2, Maher CHAABENE

2

and Fernando TADEO 3

1 Industrial Engineering school, University of Valladolid, Spain.

2 Unité de Commande de Machines et Réseaux de Puissance CMERP-ENIS,

University of Sfax, Tunisia. 3 Industrial Engineering school, University of Valladolid, Spain.

[email protected]

Abstract

The Photovoltaic water Pumping Systems (PVPS) constitute a potential option to extract water in remote locations for agriculture. This technique requires an efficient control of the system components. The aim of this work is to study the efficiency of the vector method in controlling an asynchronous machine used for water pumping. With a maximum power extracted from the photovoltaic panel, the control method is studied from the point of view of pumped water volume. For this, a typical situation is considered: A pumping system composed of a 4500 W pump driven by an asynchronous machine which is powered by a 5000 W photovoltaic array. Using measured data of irradiation and temperature, a comparison has been carried out using a detailed simulation for a medium season under the outdoor conditions of Sfax site. Through the comparison of the obtained results of different parameters as power, daily cumulative water, it has been proved that the vector control gives maximum of pumped water volume.

Keywords: Photovoltaic Pumping, vector control, water volume


- 159-

Solubility in Supercritical Carbon Dioxide of

Hydroxybenzoic Acid Isomers: Correlation and

Prediction

Loubna NASRI1, Zouhir BENSETITI

2 and Salima BENSAAD

3

1 Département de Chimie Industrielle, Université Mentouri,

Constantine, Algeria. 2 Unisignal Inc., Brossard, Quebec, Canada.

3 Département de Chimie, Université Mentouri, Constantine, Algeria.

[email protected]

Abstract

Solubility data is fundamental to the development of new supercritical applications and the enhancement of existing applications including environmental pollution, extraction and purification of pharmaceuticals, food and natural products, and natural gas industry. Hence, the ability to correlate and predict the solubility of solids in supercritical fluids is of utmost importance. In this work, we propose to correlate and predict the solubility in supercritical CO2 of disubstituted aromatic isomers of hydroxybenzoic acid with a new methodology based on the expanded liquid theory, in which the solid–fluid equilibrium is modeled using the local composition model of UNIQUAC in which the interaction parameters are related to the solvent reduced density with an empiric exponential form equations. The experimental solubility of o-hydroxybenzoic acid, p-hydroxybenzoic acid, m-hydroxybenzoic acid and mixed isomers (m-hydroxybenzoic acid+p-hydroxybenzoic acid) are used for evaluating the correlation and prediction capabilities of this new methodology. The results obtained using the proposed model show good agreement with the experimental data used.

Keywords: Aromatic isomers, supercritical fluid, correlation, prediction, solubility


- 160-

Numerical simulation of heat and mass tranfer

Koutama AMARA1, Ridha CHOUIKHY

1, AmenAllah GUIZANI

2

1LMTE/CRTEn BP 95 Hammam Lif 2050, Tunisia.

2LMTE/CRTEn BP 95 Hammam Lif 2050, Tunisia

[email protected]

Abstract

For the cases of ventilation requirements and energy saving, integrating the energy (heat and moisture) recovery ventilator and heat recovery ventilator in HVAC applications has gained more attention recently. The ventilator selected for this paper employs the rotary air-to-air energy wheel with a porous matrix s a heat or heat-and-moisture transfer medium. Such an energy wheel can operate with high effectiveness by using a low-cost porous matrix energy core. To determine the effectiveness of the energy wheel, mathematical and numerical models have been developed for a symmetric and balanced wheel operating in a counter-flow arrangement.

Keywords: Recovery energy, heat-and-mass transfer, sensible wheel, condensation wheel


- 161-

Energy Savings Potential from Replacing

Traditional Bulbs With Energy Saving Bulbs in

Residential Sector of Libya

Omar MREHEL, Alhasan ALKHAZMI, Alhousein ALKHAZMI

Tripoli University, Faculty of Engineering, Electrical and Electronic

Engineering Department.

[email protected]

Abstract

This study focus on the opportunities of saving lighting energy from the residential sector of Libya through the replacement of Incandescent bulbs (commonly used) with energy saving bulbs such as CFL, LED. The study was based on distributing questionnaires over suitable sample of electricity consumers in the residential sector. This sample covers a wide geographical region of Libya. Questionnaire will provide thorough information about type of bulbs, average number of bulbs, and the average energy consumed in each category of residential buildings in Libya. Results show that 54% and 74% of electrical energy can be saved through the use of CFL and LED respectively. The economic advantages of the replacement could save over 232 million Libyan dinar yearly. In addition to the huge environmental benefits by avoiding the emission of over1,345,492 and 1,846,539 tons of CO2 due to the replacement scenarios I and II respectively.

Keywords: Energy saving, bulbs technology, Incandescent bulb, LED bulb, CFL lamp


- 162-

Electric Drive Control: Multi-level Optimization

Efficiency

Fethi FARHANI, Chiheb BEN REGAYA, Abderrahmen ZAAFOURI and

Abdelkader CHAARI

University of Tunis Unit C3S, High School of Sciences and Techniques of

Tunis (ESSTT), 5 Av. Taha Hussein, BP 56, 1008 Tunis, Tunisia.

[email protected]

Abstract

The minimization of the electric energy consumption has become a decisive goal in the design of control systems, control and supervision while maintaining the performance and features required by these systems. In this perspective, this paper aims to contribute to the efforts of saving electrical energy. A complete solution is proposed to minimize the energy losses on the association of induction motor and its driver taking into account the algorithmic simplicity and the cost of the control system. The proposed solution minimizes total power losses on the one hand by the search of the optimum operating point of the engine; on the other hand it defines an optimal control strategy of the inverter based on power factor. The simulation was used to validate the proposed method as well as show the efficiency and robustness of the proposed technique.

Keywords: Adaptive Space-Vector Modulation (ASVM); Energy saving; Induction

machine; Vector control.


- 163-

Competitiveness Trend of Renewable Energies:

Tunisian Case

Helmi ALOUI1, Souhir HAMMAMI

2, Yassin HASSEN

2

1VEEP Research Team of the LETI Laboratory, Sfax Engineering School

(SES), University of Sfax. 2Gabes Engineering School (GES), University of Gabes.

[email protected]

Abstract

These works are made at GES in partnership with the Renewable Energy Department of the Tunisian Electricity and Gas Company (STEG - PEREE). They present the first strategic study held for the help of STEG and national political decision makers to inspect and forecast long-term issues of Tunisian power sector which is an important factor to encourage international investment in the near future. The paper focuses possibility and feasibility to apply the international energy share and distribution strategy on Tunisian power sector with an outlook to 2030. Presented study is based on a parity cost calculation of conventional and renewable energies to compare their competitiveness and profitability.

Keywords: Conventional Energy, Renewable Energy, Levelized Cost, Trends, Parity,

Competitiveness.


- 164-

Energy storage using the phase change materials:

Application to the thermal insulation

Ilhem HAWACHI 1, Habib SAMMOUDA

1 and Rachid BENNACER

2

1Laboratory of Energy and Material (LR11ES34) University of Sousse-Tunisia,

Ecole Supérieure des Sciences et de la Technologie, Rue Lamine Abbassi,

4011,Hammam Sousse, Tunisia. 2ENS-Cachan Dpt GC/ LMT /CNRS UMR 8535, 61, Av du Président Wilson

94235 Cac

[email protected]

Abstract

The energy storage, especially latent heat, is one of the most promising ways to save energy. This purpose, a study of the evolution of the melting front of a plate of wax is studying. in the presence of natural convection. A numerical model is presented. This study is based on solving the equation of the solid-liquid interface, of the Navier-Stokes and energy from a numerical procedure. In the second part we propose a numerical study of heat transfer in a multilayer wall incorporating a phase change material subject to a condition of solar radiation on the outside. The numerical results are presented on examples of materials used in the construction field in real operating conditions and we show that integration of phase change materials (PCM) into building walls is a potential method of reducing energy consumption in buildings. As validation we will study numerically and transient performance of a fixed bed filled with uniform spheres, randomly arranged and each containing a phase change material, that is why a two-dimensional theoretical model is applied to two separate phases, it was used to predict the temperature distribution of the fluid and the fusible material along the bed in the method of heat storage.

Keywords: PCM, storage, energy, building, modeling


- 165-

Storage Energy Management in Photovoltaic

Systems using the Fuzzy logic Technique

CHEKIRED Fathia, MAHRANE Achour, CHIKH Madjid, SMARA Zoubeyr,

GUENOUNOU Abdrezzak

Unité de développement des équipements solaires (UDES), route nationale

N°11, BP386, Bou-Ismail, 42415, Tipaza, Algerie.

[email protected]

Abstract

Energy management is a crucial task in photovoltaic system which takes in charge the storage and the distribution of the energy produced by the photovoltaic system in order to feed the load and to avoid any shortage of energy. As the energy storage is an important part of it, we focused on this latter by developing a Fuzzy Logic Controller which controls the charge and discharge of the lead acid batteries using the model of Coppeti.

We show that the developed storage energy management algorithm keeps the battery voltage in a safety range ensuring a longer battery lifetime and minimizing the malfunction of the photovoltaic system.

Keywords: Stand-Alone Photovoltaic Systems (SAPVS), Energy Management, Lead Acid

Battery, Fuzzy Logic, Fuzzy Controller.


- 166-

How Renewable Energy Will Change Electricity

Markets Fundamentally

Reinhard HAAS, Georg LETTNER, Hans AUER

Energy economics Group, Vienna University of Technology, Austria.

[email protected]

Abstract

In recent years in several countries with Germany leading a remarkable increase in capacities and corresponding electricity generation from wind and photovoltaic power plants took place. The core objective of this paper is to investigate the possible effects of such a further uptake of renewables on the European electricity markets. The major effects of these developments on the electricity markets will be: (i) a much higher price volatility from hour-to-hour and day-to-day; (ii) increasing relevance of intra-day markets; (iii) higher costs and prices for fossil capacities (due to higher shares of investment depreciation costs); (iv) increasing relevance of storages and “smart” grids, (vi) higher market shares for balancing markets; (vii) continuously increasing complexity of managing supply, storages and demand over time.

Keywords: renewables, electricity markets, price volatility


- 167-

Effects of Operating Parameters on the Performance

of Single Stage CO2Trans-critical Refrigeration

Cycles.

Rabah GOMRI and Nabil KHELLAF

Department of «Génie Climatique» - Faculty of Engineering,

Université Mentouri, Constantine - 25000 Constantine, Algeria.

[email protected]

Abstract

One of the solutions to minimize ozone depletion and global warming concerns is the use of natural refrigerants. In addition to its environmental advantages, CO2 offers certain attractive thermal characteristics.

In the present work it is proposed to analyse the performance of six trans-critical refrigeration cycles using CO2 as refrigerant. It is found that to obtain the best performance it is necessary to control the value of the high pressure because for each value of the outlet temperature of the gas cooler correspond an optimum value of high pressure which gives the maximum COP of the refrigeration cycle. The replacement of the expansion valve by an expansion turbine allowed a small improvement of the COP. But if the work extracted by the expansion turbine is recovered we obtain a remarkable improvement of the performance of the refrigeration cycle. When the expansion device used in the cycle is an expansion valve or an expansion turbine without power recovering, the use of an internal heat exchanger allowed only a slight improvement of the performance of the cycle. The performance of the cycle decreases when the expansion device is an expansion turbine with power recovering.

Keywords: Refrigeration; Trans-critical; Carbon dioxide; Performance


- 168-

Combustion of hythane diluted with CO2

Ibtissem HRAIECH1,2

, Mohamed HAMDI1, Jean-Charles SAUTET

2,

Abdallah MHIMID1

1 LESTE ; Ecole Nationale d’Ingénieurs de Monastir, Tunisie. 2 CORIA UMR6614 – CNRS, Université et INSA de Rouen.

Saint Etienne du Rouvray, France.

[email protected]

Abstract

With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen, H2, and natural gas, NG) has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (%H2) in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoechiometry. The results show that the liftoff height increases with the addition of CO2 at various %H2 content in hythane. However, we observe that with 20%H2, we can obtained a stable flame diluted with 40%CO2, while for 0%H2, the flame is blown above 20%CO2. This means that the limits of blowing the flame are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the %CO2 is low. At higher %CO2 dilution, flame would remain attached until blow-off. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

Keywords: Hythane, Hydrogen enrichment of natural gas flames, CO2 dilution, stability


- 169-

Perspectives for Alternative Energy Carriers Based

on Renewables from Technical and Energetic Point-

of-view

Amela AJANOVIC1, Gerfried JUNGMEIER

2, Martin BEERMANN

2

1 Energy economics Group, Vienna University of Technology, Austria.

2 Joanneum Research Graz, Austria.

[email protected]

Abstract

Alternative energy carriers (AEC), based on renewable CO2-poor or CO2-free sources of energy, are of central importance for the transition towards a sustainable energy system. The most important AEC currently discussed are: hydrogen and electricity from renewable energy sources and other AEC based on biomass. The core objective of this paper is to provide an appraisal of the prospects of these AEC up to 2050 from a technical and energetic point-of-view. The major conclusion is that there is no single “one size fits all” energy carrier which can be considered to serve all problems alone. All AEC analyzed in this paper still face major problems in different parts of the overall energy service providing chain.

Keywords: Energy carriers, technical maturity, conversion efficiency, energetic

performance


- 170-

Charge and Discharge Analysis of a Lead Acid

Battery used in Solar PV Systems

Dalila ACHELI, Fadhila LACHEKHAB, Mohamed KESRAOUI

Applied Automatics laboratory, University M’hamed Bougara, Independence

Avenue 35000 Boumerdes, Algeria.

[email protected]

Abstract

In a PV system, a battery provides power for electrical networks in the absence of the sun through the discharge after a charge. To ensure a full charge while avoiding the risk of over loading or the risk of complete discharge, a controller is necessarily willing to meet these two main functions. Analysis of these operations is the object of this paper. We will focus primarily on the study of electrochemical storage with lead acid unit. Battery behavior study and mathematical modeling will be the second point of our work. Simulation results of the charge and discharge states using Matlab/Simulink software have also been presented. As a last point experimental tests in an existing bench employing a fuzzy controller for the battery charging and discharging have been performed.

Keywords: Battery Behavior, Charge and Discharge, Current, Voltage, Solar PV System,

State of Charge.


- 171-

Design and Analysis of a High Frequency Dual

Active Bridge DC-DC Converter for Super

Capacitor Used in Electrical Vehicle

M. AMARI1, I.ELGHARBI

2 , J.GHOUILI

3 and F. BACHA

4

1,2,4Unité de Recherche en Automatique et en Informatique Industrielle (URAII),

Université de Tunis. 3University of Moncton, Canada.

[email protected]

Abstract

This work investigates the application of a dual active bridge (DAB) converter. The proposed converter topology is used as an interface between the ultra-capacitor and the fuel cell battery. It allows the bidirectional of the power transfer. The latter converter is composed of two active bridge, LC resonant filter and planar transformer. This last one is used to produce a higher voltage in secondary side 135V rms from input voltage of 12.5V (output of the super-capacitor ) and isolates the full bridge. The control strategy of the DAB is the phase shift. The DAB converter has been designed and realised and controlled by an FPGA board. The experimental results validate the efficiency of the proposed control strategy.

Keywords: Ultra capacitor, Dual Active Bridge Converter, Phase Shift, Planar

Transformer, L C resonant,

Fuel cell, Flow power, Bridge Low Voltage (BLV), Bridge High Voltage (BHV)


- 172-

Control of hybrid sources for electrical train power

supply

M. Becherif1, M.Y. Ayad

2, and D. Hissel

3

1UTBM, FCLab FR CNRS 3539, Femto-ST UMR CNRS 6174,

90010 Belfort Cedex, France. 2in R&D in Industrial Hybrid Vehicles Applications, France.

3UFC, FCLab FR CNRS 3539, Femto-ST UMR CNRS 6174,

90010 Belfort Cedex, France.

[email protected]

Abstract

Like all capacitors, the electrochemical capacitors (also called supercapacitors or ultracapacitors) are also devices which are considered to possess extra-ordinary storage capacities. The conventional electrostatic and electrolytic capacitors store charge on low-surface-area plates, but supercapacitors store charge in an electric double layer set up by ions at the interface between a high-surface area carbon electrode and a liquid electrolyte. Because of their appropriate characteristics –huge capacitance, weak serial resistance– of direct storage (energy ready for use) and easy control through the power electronic conversion, the use of supercapacitors, as storage elements, is quite suitable to the embedded electrical energy management. This paper proposes an energy source supplied by supercapacitors, as a main power source, which are charged by means of a wind generator. These supercapacitors ensure the power supply of a miniature train of 150W. This paper deals with the design, modelling and control of this modern distributed generation system. The obtained simulations with some experimental results are presented.

Keywords: Automotive control, Energy systems, Nonlinear systems.


- 173-

Biomass and Hydrogen Energy

‘BHE’

- 174-

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-BHE-35/O

- 176-

Adsorption Kinetics of Anionic dyes from Aqueous

Solutionson Activated Algerian Kaolin ”DD3” and

Bentonite

F.Z.EL BERRICHI1, S.ZEN

2,H.BOURARA

1, H.ZEGHACH

1, A.MAOUI

3

1 Laboratoire de chimie physique, Université de 8mai45, BP 401, Guelma,

Algeria. 2 Laboratoire de chimie appliquée, Université de 8mai45, BP 401, Guelma,

Algeria. 3 Laboratoire de génie civil et hydraulique, Université de 8 mai 45, BP 401,

Guelma, Algeria

[email protected]

Abstract

The discharge of the tanning industry constitutes enormous nuisances for the environment and exactly for the human health, in particular the various dyes which are used excessively to improve the dye industry. Therefore, the use of local clays in the treatment of the discharge has an important economic and environmental interest and with the aim for value the local‟s clays from Algerian East, we have selected the kaolin DjebelDebagh«DD3» low-cost material abundant in highly weathered soils. Adsorption experiments were accomplished using tannery dyes namely: coriacide bordeau 3B, derma blue R67 and the coriacide brown 3J adsorbed on activated kaolin by acid treatment. The adsorption capacity of all three dyes exceeds 90 % observed after 40 to 80 min compared as activated bentonite which presented maximum removal of 80 % for all anionic dyes. Natural and treated clay samples were characterized by chemical analyses, powder X-ray diffraction, FTIR. Finally, the obtained results confirmed the applicability of kaolin “DD3” as an efficient adsorbent for anionic dyes and from dyes wastewater.

Keywords: Kaolin « DD3 », Bentonite, Activation, Adsorption Kinetics, Anionic dyes


- 177-

Maximizing the Energy Potential of Palm Kernel

Shell by Pyrolytic Conversion to Biofuel

Edmund C. Okoroigwe1,3

, Zhenglong Li2,4

, Samuel O. Onyegegbu3 and

Christopher M. Saffron2,4

1National Centre for Energy Research and Development, University of Nigeria,

Nsukka. Enugu State, Nigeria. 2 Biosystems and Agricultural Engineering, Michigan State University, East

Lansing, Michigan, USA. 3Department of Mechanical Engineering, University of Nigeria, Nsukka.

4Chemical Engineering and Material Science, Michigan State University, East

Lansing, Michigan, USA

[email protected]

Abstract

The effect of pyrolysis conversion of Palm Kernel Shell (PKS) to bioenergy on the energy of the parent feedstock, was studied by pyrolyzing one kilogram of the biomass in a bench-scale screw-conveyor pyrolysis reactor at 450°C. The process yielded 61 wt% bio-oil, 24wt% bio-char and 14 wt% non-condensable flammable gas (NCG). The energy content of the PKS and its pyrolytic products were determined using standard methods. The higher heating value (HHV) and lower heating value (LHV) of the bio-oil are higher than those of the parent feedstock by 29% and 26% respectively on moisture free basis. Similarly, the HHV of the bio-char is 77.7% higher than that of the original PKS. There was over 95% and 37% reduction in the ash and sulphur content, respectively, of the parent feedstock when converted to bio-oil. This makes the combustion of the bio-oil more environmentally friendly than direct combustion of the PKS. Furthermore, the result of the GC-MS analysis of the bio-oil reveals the presence of useful chemicals that can be harnessed for industrial applications. The results obtained in the characterization of the products compare well with those from pyrolysis of woody biomass. The integration of energy content of the pyrolysis products is the basis for positive energy balance in the processing of PKS for energy production.

Keywords: Elaeis guineensis, Palm kernel shell, bioenergy, biomass, Pyrolysis

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-BHE-65/P

- 178-

Phytoecology protected steppes of Stipa tenacissima

after exclosure near Naama (western Algeria)

BENARADJ Abdelkrim1*

, BOUCHERIT Hafidha2, HASNAOUI Okkacha

3,

LAHOUEL Nouredine4, MEDERBAL Khalladi

5, BAGHDADI Djillali

5&

AIBOUT Farid5

1*Corresponding author: University Center Naâma, BP 66,

45000 Naâma DZA (Algeria). 2- Department of Agricultural and Forestry Sciences, University

of Tlemcen (Algeria). 3- Department of Biology, University of Saida (Algeria).

4- Department of Biology, Université de Mascara (Algeria)

5Department of Agricultural Sciences, University

ofMostaganem (Algeria)

[email protected]

Abstract

The south-oranian of Naâma (Algeria) is a representative example of drylands threatened by the scourge of desertification. The intervention measures to this alarming situation are to promote the opposite process of degradation by the recovery and rehabilitation of degraded steppe about Stipa tenacissima in the art of exclosure (fencing). This technique promotes natural regeneration, the most appropriate to induce the recovery of natural biological steppe species. After this assessment, the fencing has a positive impact in terms of biological feedback (increase the recovery rate of vegetation, the floristic richness, density, the phytomass and the improvement of physical and chemical soil). It should obey a sound management of course closed for protection after opening the respect of the charge, it is with these requirements that solutions of jobs are offered to local conditions to keep the course in good condition for future generations.

Keywords: Steppe, Naâma, Algeria, Stipa tenacissima, biological recovery, exclosure,

desertification.


- 179-

Experimental investigation of CO2Separation from

Lignite Flue Gases by Molten Carbonate Fuel Cell

Jarosław MILEWSKI, Wojciech BUJALSKI, Marcin WOTOWICZ, Kamil

FUTYMA, Jan KUCOWSKI, Rafał BERNAT

Warsaw University of Technology, Institute of Heat Engineering.

[email protected]

Abstract

The paper presents an experimental investigation of using a Molten Carbonate Fuel Cell (MCFC) for CO2 emission reduction made from the flue gas of a lignite fired boiler. The MCFC is placed in the flue gas stream and separates CO2 from the cathode side to the anode side. As a result, a mixture of CO2 and H2O is obtained; from which pure CO2 can be obtained by water condensation. The main advantages of this solution are: additional electricity generated, reduced CO2 emissions and higher system efficiency. The results obtained show that the use of an MCFC could reduce CO2 emissions by 90% with above 30% of efficiency in additional power generation.

Keywords: Molten Carbonate Fuel Cell, CO2 separation, laboratory experiments


- 180-

Experimental study of oxytetracycline retention by

adsorption by the peanut shells coated with the

polyaniline

BELAIB.F, MENIAI. A-H, MOKRI.A, BOUKELLAL.B

Laboratory of the engineering and the processes of environment(LIPE).Dep of

industrial chemistry.Faculty of Science of engineer ,University of Constantine,

25000,Algeria.

[email protected]

Abstract

Following their use, drugs are often partially metabolized, and these pharmaceutical substances or their metabolites are continuously released into the environment.Their presence in water is an emerging pollution. Among the pollutants, pharmaceuticals, oxytétracyclines that are used in large quantities, it is essential to reduce their presence in aquatic environments. In this work we applied the adsorption process on peanut shells coated with polyaniline on oxytetracycline, the solutions are prepared with distilled water and equipped for testing of adsorptions; the influence of different physico-chemical parameters such as contact time, concentration, solution pH, ionic strength, temperature was studied. The effect of coating is more evident from the yields of retention. The thermodynamic study shows that the reaction is exothermic. The results confirm the effectiveness of the adsorption process for the decontamination of aquatic environments loaded with oxytetracycline.

Keywords: Oxytetracycline-Adsorption-coating-Peanut shells-Kinetic


- 181-

Comparison Between the Effect of Acid and Basic

Chemicals Activation of Cedar cone on the Sorption

of Rhodmaine B from Aqueous Solution

Meriem ZAMOUCHE1,2

, Sihem ARRIS1 and Mossaab BENCHEIKH

El HOCINE1

1Laboratory of the engineering and the processes of environment (LIPE),

Department of industrial chemistry, Faculty of Science of the engineer,

University of Constantine, 25000, Algeria. 2Biotechnology National Research Center, Constantine, Algeria.

[email protected]

Abstract

The aim of this work is to obtain optimal preparation conditions of cedar cone by different activation reagents for removal of cationic dye from aqueous solution. The activated cedar cone was prepared by chemical activation, using basics and acids reagent such as: H3PO4, H2SO4, HNO3 for the acids reagents and NaOH, Na2SO4, Na2CO3 for those basic, at the same concentration which is 0.1mol/L. It was found that the sorbent activated by acids reagents give the higher capacity of sorption compared with no activated and basic activated sorbent. The effects of acids reagents concentration were investigated. The kinetic data were fitted to pseudo-first-order, pseudo-secondorder, intraparticle diffusion and Boyd models. The sorption kinetics was found to follow the pseudo-second-order kinetic model. The acids activated reagents, whichgive the best sorption with minimum equilibrium time is HNO3, with concentration of 2 mol/L.

Keywords: Cedar cone, Rhodamine B, Kinetics, basic activatedreagent, acid activated

reagent


- 182-

Gaseous products and particulate matter emissions

of biomass residential boiler fired with spent coffee

grounds pellets

L. LIMOUSY1, M. JEGHIRIM

1, S. DORGE

1, D. KEHRLI

1, P. DUTOURNIE

1,

M. LAJILI2

1Laboratoire Gestion des Risques et Environnement, Université de Haute

Alsace, 3 bis, rue Alfred Werner 68093 Mulhouse, France. 2Ionized and Reactive Media Studies (EMIR), Preparatory Institute of Engineers

Studies of Monastir (IPEIM), Avenue of Ibn El Jazzar, 5019 Monastir, Tunisia.

[email protected]

Abstract

In this present work, energetic characteristics and combustion behaviour of agropellets produced from pure Spent Ground Coffee (SGC) or blended with pine sawdust in a commercial residential pellet boiler were examined. Hence, the thermal and chemical properties such as calorific value, ash content, bulk density, fixed carbon and elemental analysis were obtained from blend and pure biomasses was firstly examined. Moreover, according to the French standards the following gases were analyzed during the combustion tests in 8-12 kW Okofen boiler: CO and the total organic carbon (TOC). The emissions of some gases were also monitored during combustion: O2, CO2, NO and NO2. An Electrical Low Pressure Impactor (ELPI) was used to collect particles from 29 nm to 10 μm into 12 size fractions to determine mass and number concentrations.It was found that the lower heating value of SCG pellets is 16090 MJ/kg. The gaseous emission indices of CO, NOx and TOC in the exhaust are compared with emissions of wood pellets (with DIN+ standard). According to the presented results, it seems reasonable to consider SCG pellets as a promising candidate as alternative fuel. Nevertheless, the use of SCG as a standard biomass fuel (agropellets) could meet French Standards only with SCG blending up to 50% with pine sawdust.

Keywords: Spent Coffee Grounds, Biomass mixture, Agropellets, Combustion tests,

Gaseous Emissions


- 183-

The use of olive waste for agropellets production:

Characterization study

M. LAJILI1, L. LIMOUSY

2, M. JEGUIRIM

2, D. KEHRLI

2, R. SAID

1

1 Unité de recherche Etude des Milieux Ionisés et Réactifs (EMIR), IPEIM,

Avenue Ibn Eljazzar Monastir 5019, Tunisie. 2 Laboratoire Gestion des Risques et Environnement, Université de Haute

Alsace, 3 bis, rue Alfred Werner 68093 Mulhouse, France.

[email protected]

Abstract

This study aims to produce agro-pellets composed by olive waste blended with pine sawdust for 6 different mass fractions compositions. Thermal and physic-chemical properties of these pellets such as moisture and ash contents, bulk density and high heating value were determined. In addition, thermogravimetry analyses were performed in order to assess the thermal degradation behavior of the produced agro-pellets. Results show that the high value of moisture in olive waste decreases during the pelletization, values of ash for each considered sample remains in the accepted European standards. Thermogravimetric analysis shows that the produced pellets thermal degradation follows the usual behavior of the lignocellulosic materials. However, a higher reactivity for PS/OW agro-pellets is observed comparing to those found in literature. Such results prove that olive waste agro-pellets may be an alternative for producing energy in domestic boilers.

Keywords: Olive waste, pine sawdust, pellets, energetic properties, thermogravimetry.


- 184-

Numerical study of surface waves generated by

sudden movement at the sea bottom

Belgacem GHOZLANI, Zouhaier HAFSIA, Khlifa MAALEL

Laboratoire de Modélisation en Hydraulique et Environnement.

Ecole Nationale d’Ingénieurs de Tunis, Tunisia.

[email protected]

Abstract

Time dependent surface deformations of a hydrostatic water volume, when it is subjected to a sudden partial rise of the sea bottom, is examined numerically in this paper. The present numerical model is based on the Navier-Stokes equations and the volume of fluid (VOF) method. The CFX code is adopted to solve these transport equations. The Immersed Solid technique (IMS) is used to follow the motion of the sea bottom. This model is first validated by comparing with the available experimental data. A good agreement was obtained between the numerical and experimental results giving confidence in the further use of CFD models similar to these. In the second step, various computational tests are done for the selection of computational parameters of the model. It is found that the amplitude of surface waves generated by vertical displacements of the sea bottom depends on size and speed of bottom displacements.

Keywords: surface waves, bottom motion, tsunami, CFX code.


- 185-

Proton conducting hybrid membrane electrolytes

based on Sulfonated poly(ether sulfone)s and

Metallophthalocyanine contained poly(ether

sulfone)

Young-Don Lim1, Dong-Wan Seo2, Soon-Ho Lee1, Md. AWLAD HOSSAIN1,

Seong-Young Choi1, Jin-Seong Lim1 and Whan-Gi Kim1

1Department of applied chemistry, Konkuk Univ., Chungju, 380-701, Korea.

2Energy Materials Research Center, Korea Research Institute of Chemical

Technology, P.O. Box 107, Yuseong, Daejeon 305-600, Republic of Korea.

[email protected]

Abstract

Metallophthalocyanine (MPc) is a potent catalyst for hydrogen peroxide oxidation, and the mechanism of H2O2 decomposition in solution has been previously explored (H2O2 -> 2H+ + O2 + 2e-). This work presents a role of MPc as an anti-oxidizing agent of polymer membrane, and also as an accelerating agent of proton. poly(arylene ether sulfone)s contained MPc (Ni, Co and Fe) (PMPc) was prepared by two-step reaction from phenolphthalein and fumaronitrile, and followed reaction with metal (II) chloride (Ni, Co and Fe) and 1,2-dicyanobenzene in quinoline. The sulfonated polymers were synthesized by condensation polymerization using 1,2-bis(4-hydroxyphenyl)-1,2-diphenyl ethylene, 4,4-fluorophenylsulfon, and sulfonated with sulfuric acid. A series of hybrid membranes (H-Ni, H-Co and H-Fe) were prepared from a mixture of sulfonated-copolymers and PMPcs and casted from dimethylacetamide (DMAc). The structure properties of the synthesized polymers were investigated by 1H-NMR spectroscopy and FTIR. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. The deterioration test was performed by Fenton reagent, and compared with normal sulfonated poly(ether sulfone)s and Nafion.

Keywords: PEMFC, fuel cell, membrane, phthalocyanine, polymer


- 186-

A PEM Fuel Cell Modeling : First Approach

B. Abderezzak1, B. Khelidj

2 and M. Tahar Abbes

1

1 Laboratoire de Mécanique et EnergétiqueUniversity

Hassiba Benboualiof Chlef, Algeria. 2 Laboratoire de Fluides Industriels et Mesures Appliquées,

University of Khemis Miliana, Algeria.

[email protected]

Abstract

In the last 20 years, many scientists have moved to the hydrogen and fuel cell field, it‟s a very important energy system, very clean and renewable, the developed countries tried to build factories and to be the first to obtain this technology. Numerous applications exist, one of the promising applications is the automotive industry which already has buses and cars running on Polymer Electrolyte Membrane (PEM) fuel cells using hydrogen as a fuel, this system is one of the cleanest and most efficient technologies for generating electricity. Since there is no combustion, there are no pollutants commonly produced by boilers and furnaces [1], it has also the potential to replace the internal-combustion engines in vehicles and provide power in stationary and portable power applications because they are energy-efficient, clean, and fuel-flexible. For this report a comprehensive literature survey has been conducted. The findings of the literature survey include fuel cell models that fit into two broad categories, that is, analytical and empirical. Analytical models are theoretically based, whereas empirical models are experimentally based. This research work is a presentation of a static modeling tool on PEM fuel cells.

Keywords: Hydrogen, Polymer Electrolyte Membrane Fuel Cells, Static Modeling


- 187-

Combustion tests of date palm residues in a small

pellets boiler for energy recovery

Y. ELMAY1,2

, M. JEGUIRIM1, S. DORGE

1, G. TROUVE

1 and R. SAID

2

1 Laboratoire Gestion des Risques et Environnement, 3 bis, rue Alfred Werner

68093 Mulhouse, France. 2 Unité de Recherche d’Etude des Milieux Ionisés et Réactifs, IPEIM (UR

EMIR), Avenue Ibn El Jazzar 5019 Monastir, Tunisie.

[email protected]

Abstract

Agriculture residues are a promising alternative to locally produce renewable energy in Tunisia. This work presents an experimental study on two main date palm residues (date stone and date rachis). Physicochemical characteristics such as ultimate and proximate analyses and energy contents were determined. The two date palm residues were combusted in a small-scale pellets boiler. Gaseous (CO, CO2, NOx, CxHy) and particles emissions were measured in the exhaust and efficiency parameters were calculated. The pellets boiler was setup following the manufacturer‟s recommendation to burn wood pellets. Experimental tests show that despite their high LHV and combustion efficiencies, date rachis pellets and date stones lead to lower boiler efficiencies, which were flowed by higher emissions of VOC than those obtained for a premium grade wood pellet. These behaviours were expected in such boiler which is set up to burn wood pellets with precise adjustments of airflow and fuel feed rate. Despite these shortcomings, this work is still interesting by proving that date palm biomass can be energetically upgraded in pellet boiler and date stones are especially very benefit since they can be used without densification. By utilizing various additives and processing techniques, date rachis could be used to manufacture a pellet fuel that has commercial potential. However, several investigations still remain in order to minimize the ash content and to determine the optimal settings for improving combustion.

Keywords: Date palm biomass, pellets boiler, gas emissions, particulate emissions


- 188-

Preparation and N2, CO2 adsorption of activated

carbon pellets derived from olives stones

Wahid DJERIDI1, Abdelmottaleb OUERDANI

1, Andrew D.WIESUM

2, Philip

L.LLEWLLYN2 and Lassaad El MIR

3,4

1Research Laboratory: Engeneering Process et Indstrial Systems, National

school of Engineers of Gabes,University of Gabes,St Omar

Ibn Elkhattab, 6029 Gabes, Tunisia. 2Chimistry laboratory of Provence, University Aix-Marseille I, II, III-

CNRS, UMR 6264,

[email protected]

Abstract

This paper analyses from a fundamental point of view the adsorption of CO2 on microporous carbons. CO2 adsorption on a series of microporous activated carbon pellets (ACP), prepared from olives stones without a binder. Experiences were conducted at room temperature and in the pressure range between 1 and 23 bars.

The effect of pyrolysis temperature on carbon materials texture and CO2

adsorption uptake are studied. The characterization of carbon materials is performed by scanning electron microscopy (SEM) and nitrogen adsorption (BET). The results reveal that all the pellets are essentially microporous and had high CO2 adsorption capacity. The highest CO2 adsorption value is 9.52 mmol/g at 303 k and 23 bars.

Keywords: Acivated carbon pellet, pyrolysis temperature, porous texture, CO2 adsorption


- 190-

Simultaneous biohydrogen production and

wastewater treatment based on the selective

enrichment of the fermentation ecosystem

Iulian Zoltan Boboescu1, Vasile Daniel Gherman

1, Ion Mirel1, Bernadett Pap

2,

Roland Tengölics3, Gábor Rákhely

3,4, Éva Kondorosi

4 and Gergely Maróti

1,4*

1 “Politehnica” University of Timisoara, Hydrotechnical Engineering Dept.,

Timisoara, Romania. 2 Seqomics Biotechnology Ltd., Szeged, Hungary.

3 University of Szeged, Dept. of Biotechnology, Szeged, Hungary.

4 Hungarian Academy of Sciences, Biological R

[email protected]

Abstract

Biohydrogen production from synthetic wastewater as substrate was studied in anaerobic small scale batch reactors. Enriched anaerobic mixed consortia sampled from various environments were used as parent inoculums to start the bioreactors. Selective enrichments were achieved by various physical and chemical pretreatments. Experimental data showed the feasibility of biohydrogen production using synthetic wastewater as substrate. The hydrogen generation capability of the different mixed consortia is clearly dependent on the pretreatment methods. The described approach opens the possibility for an alternative way towards simultaneous wastewater treatment and renewable energy generation.

Keywords: biohydrogen, pretreatment, microbial consortia, synthetic wastewater


- 191-

An experimental study of combustion in spark

ignition engine

OULEDSAID Amel1, MEDAERTS Florence

2, BENTAHAR Fatiha

1

1 USTHB, Faculty of mechanical genius and processes genius, Laboratory of

transfer phenomena, Bab Ezzouar,BP 32 El Alia, 16111,Algerie. 2 Institut des Sciences Appliquées, Rouen, France.

[email protected]

Abstract

Hydrogen has been considered as an attractive alternative fuel for internal combustion engines due to its high heating value, its wide range of flammability limits and clean fuel. In the present study, a combustion system has been developed for a spark ignition engine using 15% in volume of hydrogen in pure methane. Detailed experiments have been carried out to investigate the combustion operating with different values of equivalence ratio equal to 0.67; 0.75 and 0.81 at two distinct loads of 100% and 50% .

Keywords: Cylinder pressure, combustion, equivalence ratio, hydrogen, methane, SI

engine


- 193-

Experimental investigation and combustion analysis

of biogas with different compositions in dual fuel

diesel engine

Elias DAOUK1, Khaled LOUBAR

1, Mohand-Said LOUNICI

2

and Mohand TAZEROUT1

1GEPEA, UMR 6144, Département Systèmes Energétiques et Environnement,

Ecole des Mines de Nantes. La Chantrerie, 4 rue Alfred Kastler, B.P. 20722,

44307, Nantes, France. 2Laboratoire d’Energétique, Mécanique et Ingénieries, UMBB, Boumerdes,

35000, Algérie.

[email protected]

Abstract

An experimental investigation was performed to study dual fuel diesel engine using biogas with different compositions. A comparison was made with conventional diesel operation. In order to analyze this mode of combustion, in-cylinder pressure and heat release rate diagrams were evaluated. The results of this study have demonstrated the benefit of the dual fuel mode operating with biogas as primary fuel at high loads.Regarding the composition of biogas, our results showed that the biogas containing approximately 70% methane by volume and about 30% carbon dioxide is the most advantageous in terms of performances and emissions as well.

Keywords: Diesel engine, dual fuel, biogas, combustion, cylinder pressure


- 194-

Environmental chemistry and mineralogy of

particulate air matter at The phosphate mining

basin of Gafsa

MOHAMED Raja, TAIEB Dalila, BEN BRAHIM Ammar

Unité de Recherche Thermodynamique Appliquée UR11ES80

ENIG- Rue Omar Ibn-Elkhattab 6029, Gabès,Université de Gabès.

[email protected]

Abstract

The study aimed at chemical and mineralogical characterization of whole particulate matter (PM) in the vicinity of a mining phosphate basin at urban area in Gafsa. Heavy metals concentrations in PM samples (Cd, Fe, Cu, Mn, Cr,Zn, Ni,Al,Pb), MgO and SiO2 were determined by atomic absorption spectrometry. Calcium and phosphorus oxides (CaO,P2O5) were analyzed by Technicon Auto-analyzer . Potassium and sodium oxides (K2O,Na2O) were analyzed by flame photometerThe mineral phase identified by X-Ray powder diffraction technique and SEM-EDX provides information about morphology of PM. As regards the chemical characterization it was found that samples were enriched predominantly in SiO2,CaO and P2O5 which were detected only at mining area (S2 and S3) Weak concentrations of K2O,Na2O and MgO were also found. In addition the minerals phases identified in the samples were carbonate fluorapatite, Calcite, Heulandite, Gypsum and Dolmite. Results also showed that heavy metals pollution increased by the proximity to the mining area. SEM-EDX revealed that particles are almost spherical.

Keywords: Dust; Mining pollution, Metals; Mineralogy; Mining basin, Gafsa


- 196-

Modeling of heat and mass transfer in porous

reactive media

A. BOUSRI1, K. BOUHADEF

1, H. BBEJI

2 and R. NEBBALI

1

1USTHB University, Faculté de G M &G P, Laboratoire LTPMP. BP 32, El

allia Bab Ezzouar 16111 Algers, ALGERIA. 2Université de Picardie Jules Vernes, Laboratoire LTI. FRANCE.

[email protected]

Abstract

A two dimensional mathematical model has been developed to simulate the coupled heat and mass transfer in a duct filled with a porous medium, undergoing a strong exothermic reaction. The problem has received a lot of interest due to its relevance in a wide variety of engineering applications such as heat pipes, nuclear reactors, drying technologies, catalytic reactors and others. The fluid flow is modeled via the Darcy-Brinkman equation. This model and the conservation energy and mass equations are solved numerically by using the finite volume method, and the code is validated by comparison with previously published works. The influence of the exothermic chemical reaction on the heat and mass transfer in the porous medium is discussed. The effects of pertinent parameters such as the geometry, the Reynolds number and the Frank-Kamenetskii number were analyzed. Quantitative and qualitative results are presented. Comparisons with other works in the literature are performed and excellent agreement between the results is obtained.

Keywords: Heat transfer, Mass transfer, Thermal equilibrium, Porous media and Catalytic

reactor.


- 197-

Effect of geometrical parameters on the transfer of

charges in the PEM fuel cell

Badreddine LARBI, Wael ALIMI, Ridha CHOUIKH, Amenallah GUIZANI

Energy Researches and Technologies Center, CRTEn, Bordj Cedria, Hmmam

Lif, Tunisia.

[email protected]

Abstract

The objective of this study is numerical modeling, two-dimensional, charges transfer in the cathode, the anode and the membrane of the PEMFC. A program based on the finite volume method was carried out to simulate the system of equations. This model visualized the transition from community continues (channel) to the porous media (gas diffusion layer GDL, catalyst layer and the membrane) and the effect of geometry on the distribution of various model parameters in the single cell.

The cell performance was derived based on operating parameters, temperature, pressure, water content and the thickness of the membrane.

Keywords: PEMFC, Transfer, geometry


- 198-

Hydrogen permeability of Al2O3-CuO-ZnO/Ni

composite membrane

Saet Byol Rim, Mie Won Jung

School of Biological Sciences and Chemistry/ Institute of Basic Science,

Sungshin Women’s Univ., 136-742 Seoul, Korea.

[email protected]

Abstract

The Al2O3-CuO-ZnO (ACZ) powder was obtained from aluminum isopropoxide, copper (II) nitrate hemi (pentahydrate), Zinc (II) nitrate hexahydrate and using non-ionic surfactant span 80 or not by sol-gel process. This powder was characterized by TG/DTA, XRD, BET and FE-SEM results. ACZ-Ni composite membrane was prepared by hot press sintering (HPS) with help of the nickel powder to improve chemical and mechanical stability. Hydrogen permeation experiments were performed by Sievert's type hydrogen permeation equipment. The hydrogen permeability of ACZ/10 wt.% and ACZ/20 wt.% Ni was a 7.2 and 8.5 mol m-2 s-1 at room temperature, respectively. The permeability of these composite membranes was increased along with raising temperatures and pressures.

Keywords: Al2O3-CuO-ZnO, Span 80, HPS, Hydrogen permeability


- 199-

Synthesis and properties of sulfonated poly(ether

sulfone)s containing a mixture of cis and trans

mesonaphthobifluorene moiety using bis(4-

hydroxyphenyl)-1,2-diphenylethylene for PEMFC

Young-Don Lim1, Dong-Wang Seo

2, Tae-Whan Hong

3, Dong-Min Kim

4,

Hyun-Chul Ju5, Whan-Gi Kim

1

1Department of applied chemistry, Konkuk Univ., Chungju, 380-701, Korea. 2Energy Materials Research Center, Korea Research Institute of Chemical

Technology, P.O. Box 107, Yuseong, Daejeon 305-600, Republic of Korea. 3Department of Materials Science and Engineering, Korea National University

of Transportation, Chungju, Chungbuk, 380-702, Korea. 4 Material engineering & Science, HongikUniv, Jochiwon-eup, Yeongi-gun,

Chungnam, 339-701, Korea. 5 School of Mechanical Engineering Inha University253 Yonghyun-Dong,

Nam-Gu, Incheon 402-751, Korea

[email protected]

Abstract

The sulfonated poly(ether sulfone)s containing a mixture of cis and trans of mesonaphthobifluorene moiety were synthesized and characterized their properties. The mesonaphthobifluorene moiety is consisted of 6 phenyl rings and conjugated together to form planar sheets of sp2-bonded carbon. Poly(arylene ether sulfone)s containing a mixture of cis and trans of tetraphenyl ethylene units were synthesized by polycondensation and converted to graphene by Friedel-craft intra cyclization with Lewis acid (FeCl3). The sulfonation was taken selectively on tetrabenzonaphthalene units with concentrated sulfuric acid. The structure properties of the sulfonated polymers were investigated by 1H-NMR spectroscopy. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. The synthesized polymer electrolyte membranes do these properties apply into the polymers structure for improvement of thermal and dimensional stabilities.

Keywords: PEMFC, polymer electrolyte membrane, fuel cell, tetrabenzonaphthalene,

nano graphene


- 200-

Effects of PTFE variation of anode backing layer to

use of high concentration methanol fuel in a direct

methanol fuel cell

Kyungmun Kang, Sunghyun Park, Hyunchul Ju

School of Mechanical Engineering, Inha University, 253 Younghyun-Dong,

Nam-Gu, Incheon, 402-751, Republic of Korea.

[email protected]

Abstract

Under highly concentrated feed methanol fuel, high performance of a direct methanol fuel cell (DMFC) is determined by the methanol, water transport process and their interactions, which can be controlled by suitable membrane-electrode assembly (MEA) designs. In order to control the methanol and water crossover, three different novel MEAs with non-uniform and uniform polytetrafluoroethylene (PTFE) coated backing layer on the anode have been experimentally studied to utilize high methanol-feed concentrations. It is clearly shown in polarization curves that the non-uniform PTFE coated backing layer influences the cell performance under high concentration methanol feed due to the reduced methanol crossover from the anode to cathode. Using a MEA with PTFE content gradually decreases from flow channel to micro porous layer (MPL), the experimental results report that the maximum power density of 75 mW/cm2 is attained at the methanol feed

concentration of 8 M and cell operating temperature of 60 ℃. This paper concludes that controlling the hydrophobicity of the anode backing layer is key factor that can operate a DMFC under highly concentrated methanol feed.

Keywords: Direct methanol fuel cell, Methanol crossover, PTFE, High concentration

methanol fuel


- 201-

The effects of multi-layer electrode design in direct

methanol fuel cells

Johan Ko, Kyungmun Kang, Sunghyun Park, Hyunchul Ju

School of Mechanical Engineering, Inha University.

[email protected]

Abstract

In a direct methanol fuel cell (DMFC), optimizing a design of multi-layer electrode is critical to mitigate methanol crossover and improve cell performance. In this work, we present a one-dimensional (1-D) two-phase model based on the saturation jump theory to explore methanol and water transport characteristics under various multi-layer electrode configurations. In general, the numerical predictions agree well with the experimental data. Numerical simulations are also carried out to more precisely examine the role of anode and cathode MPLs on reactants and liquid saturation distributions inside DMFCs. This study demonstrates quantitative accuracy of the saturation jump model to simulate multi-layer DMFC membrane electrode assemblies (MEAs) and also provides greater insight into DMFC operational characteristics under multi-layer electrodes.

Keywords: direct methanol fuel cell, micro-porous layer, multi-layer electrode, saturation

jump model


- 202-

Fuel Cell Emulator and High Efficiency Control

Ahmed BELKHECHINE1, Brahim KHIARI

1, Jean CRISTOPHE OLIVIER

2,

Anis SALLEMI3

1LPV, CRTEn, TUNISIA,

2IREENA, Polytech Nantes France,

3ESSTT Tunis.

[email protected]

Abstract

A great number of power converters dedicated to fuel cells have been studied. However, very few studies have been undertaken on the interactions between fuel cells and power converters.

This paper presents a Maximal Power Point Tracking Algorithm (MPPT) to improve

the performance of a fuel cell as a power generation system. The first part of the paper presents an appropriate model for the fuel cell behavior based on the design of an equivalent and analogue electrical circuit describing the fuel cell operation. This leads to a fuel cell simulation model, built to emulate its electrical behavior. As a power generation unit, an MPPT-Algorithm is very useful based on the Perturb and Observe (P&O) approach. This control strategy operated the fuel cell emulator on the maximal power point regardless of the load. Simulations results are presented to validate emulator design and robustness of the control strategy using Matlab/Simulink.

Keywords: DC-DC power Converter, Fuel cell emulator, cascade control loop, MPPT

control.


- 203-

Experimental study of biodegradability of dairy

wastes in mesophilic conditions

DERBAL Kerroum, BOUMAZA Amina, GUESSOUM Hala, BENCHEIKH-

LEHOCINE Mossaab, MENIAI Abdesslem

Laboratoire de l’Ingénierie des Procédés de l’Environnement (LIPE),

Département de Chimie Industrielle,

Faculté des Sciences de l’Ingénieur, Université Mentouri de Constantine,

Algeria.

[email protected]

Abstract

Anaerobic digestion has proven to be an adequate technique for the treatment of the solid wastes rich in biodegradable organic matter which, under the action of micro-organisms, is transformed into methane rich biogas (50-75%) which can be used as an energy source for heating or to produce electricity. The present study reports the obtained results concerning the determination of the biodegradability of dairy wastes issued from a local dairy unit, under mesophilic conditions. The experiments were carried out in identical batch reactors of 570 ml in volume, kept at 35°C in a thermostatic device, for an incubation period of 80 days. A priori a characterisation of the dairy waste and the sludge was carried out. The results showed that the waste was very rich in biodegradable volatile matter (86.52 % TVS), stimulating this anaerobic digestion based type of treatment and valorisation. The results did also show that the net biogas volume under mesophilic conditions increased with the increase of the dairy waste load to the reactor, and the methane percentage in the biogas varied from 42 to 53.31% for the different considered cases.

Keywords: Dairy waste, biodegradability, mesophilic, biogas; sludge.


- 204-

Lattice Boltzmann simulation of two-phase flow in

bipolar plat of PEM fuel cell

BEN AMARA Mohamed El Amine1, BEN NASRALLAH Sassi

2

1Laboratoire de la Maîtrise de l'Energie Eolienne et de la Valorisation des

Déchets (LMEEVED)

Centre des Recherches et des Technologies de l'Energie Technopole de Borj-

Cédria. Route Touristique de Soliman. B.P. 95, 2050 Hammam-Lif, Tunisia. 2 Laboratoire d'Études des Systèmes Thermiques et Énergétiques, École

Nationale d'Ingénieurs de Monastir, Monastir 5019 Tunisia.

[email protected]

Abstract

This paper deals with the numerical simulation of two-phase laminar flow in bipolar plat of PEM fuel cell using Lattice Boltzmann model based on Shan-Chen model with a low density ratio. The flow distribution in discontinuous channels was simulated on a D2Q9 scheme under BGK approximation; the density field, pressure field and fluid structure are presented. Results show that density field is homogeneous in the plate, recirculation zones appear near the entrance of channels and the formation of a gas film on the channels walls.

Keywords: Lattice Boltzmann, two phase, Bipolar plate, fuel cell


- 205-

Effect of the flow variation on the tracer transport

in a soil column for two porous media

Sana DARDOURI1, Tawfik FILALI

2, Jalila SGHAIER

3, Ahmed BELLAGI

4

1Thermal and thermodynamic research unit of the industrial processes.

2Electronic engineering department: ENIM.



[email protected]

Abstract

We want through this study, to solve the ground contamination problem and the groundwater pollution which is resulted from the coupling of the water flow problem and the aqueous solutions transport problem. To solve this problem, we designed and produced a probe with four electrodes automated with an acquisition chart. This acquisition chart is made up of a whole of the electric elements (ADC, operational amplifier, connection RS232…) and programmed under Delphi. We tested this probe and we handled in an experiment of the ground column in order to measure the pollutant concentration in a sandy medium by measured the electrical conductivity in different conditions to study the parameters that controlled the tracer transport . A program under Delphi enables us to visualize the temporal evolution of electrical conductivity.

Keywords: electrical conductivity, pollutant, porous media, transport


- 206-

Electrochemical Model of External Reforming Solid

Oxide Fuel Cells

Abdullatif MUSA1 and Adel AGINA

2

1Faculty of Engineering, Tripoli University, Tripoli, Libya. 2National Agency for Scientific Research, Tripoli, Libya.

[email protected]

Abstract

The solid oxide fuel cell (SOFC) is considered extremely suitable for electrical power plant application. In order to better understand the thermodynamics of fuel cell high temperature (HT) SOFC and intermediate temperature (IT) SOFC models are built in Aspen customer modeller for the externally reformed. Moreover, this work introduces a new approach, through a novel software application, to the development of SOFC models, which is called Al-Nour V.1.0-2012 software application. Al-Nour V.1.0-2012 software has been prepared using a number of sophisticated programming languages (DHTML, Java, and JavaScript) where the interface and mechanism of the software were implemented based on a number of theories in Educational technology and psychology. The performance of HT-SOFC and IT-SOFC models are evaluated and compared. The simulation results show that, the activation, the concentration and the Ohmic overpotential increase with increasing current density, but the activation, and the Ohmic overpotential decrease with increasing operating temperature. Moreover, the IT-SOFC has a higher cell voltage than the HT-SOFC.

Keywords: Fuel cells; SOFC; Modelling


- 207-

Single and Multi-component Adsorption of 2-

Nitrophenol and Salicylic Acid onto Chemical Olive

Stones Activated Carbon

Amina BEDOUI1 , Souad SOUISSI-NAJAR

2 , Abdelmottaleb OUEDERNI

3

1 UR: Chemical Reactors and Process Control, National School of Engineers of

Gabes, Mednine Street 6029, Tunisia. 2,3

UR: Chemical Reactors and Process Control, National School of Engineers

of Gabes, Mednine Street 6029, Tunisia.

[email protected]

Abstract

The use of activated carbon prepared from olive stones via chemical activation (OSACC) has been investigated to remove 2-nitrophenol (2NP) and salicylic acid (SA) compounds from an aqueous solution in a batch process. The adsorption studies were carried out both in single and multi-component systems at 30°C and 3<pH<4. Commercial activated carbon was used for comparison The uptake of 2-nitrophenol was found to be greater than that of salicylic acid. In binary component adsorption, the sorption capacity decreases when the second solute is present. The extent of reduction in sorption capacity decreases in the order SA >2NP. Adsorption data on derived carbon follows the Langmuir model (LM) in single adsorption.

Keywords: Words_Activated carbon; adsorption; salicylic acid; 2-nitrophenol


- 208-

Modelling of an offshore hydrogen production from

wave energy

FERNANDO Tadeo, ALVARO Serna

Systems and Process Engineering Group, University of Valladolid.

[email protected]

Abstract

This paper describes the models for offshore electrolysis powered by renewable energy of an installation that combines a renewable energy generation system, a reverse osmosis (RO) plant to produce clean water and electrolyzers to produce hydrogen. The electricity generation is performed with devices that convert wave energy into electrical energy. The aim is reproduce the effect of varying values such as the incoming water flow from the sea or sea conditions (height or wave period) on the hydrogen production. The key idea is to use the hybrid system model to predict how they the output values are affected when there are changes in the input values, in order to later develop a predictive control system.

Keywords: Hydrogen, offshore, hybrid, renewable.


- 209-

The electrical properties of sputtered GDC thin

films on sapphire for solid oxide fuel cell

Ki-Seong Lee, Soo-Man Sim, Hyun-Doek Beck, Dong Min Kim

Department of Materials Science and Engineering, Hongik University.

[email protected]

Abstract

Gd2O3-doped CeO2 (GDC) thin films were deposited on (0001)Al2O3 substrates using RF magnetron sputtering in a temperature range of 500-700°C. The microstructures of the GDC thin films were determined through XRD. The lattice parameter increased as the deposition temperature increased. This change in a lattice parameter is related to the segregation of Gd2O3 from the GDC. The GDC thin films deposited at lower temperatures did not form homogeneous solid solutions between Gd2O3 and CeO2 where Gd2O3 was segregated. By contrast, the GDC thin films formed homogeneous solid solutions between Gd2O3 and CeO2 at higher deposition temperatures without Gd2O3 segregation. The results of the electric conductivity and ac impedance measurements were consistent with XRD analysis.

Keywords: GDC, Sputtering, Thin film, Electrolyte, Impedance


- 211-

The effect of heat treatment on the catalytic

properties of cobalt based electrocatalyts on carbon

nanotubes prepared by sputtering

Ki-Seong Lee1, Minku Lee

2, Dongil Kim

3, Tae-whan Hong

4, Hyun-Cheol Ju

5,

Whangi Kim6, Dongmin Kim

1

1Department of Materials Science and Engineering, Hongik University,2639

Sejongro, Sejong 339-701, Korea 2Nuclear Materials Development Division, Korea Atomic Energy Research

Institute,Yuseong, Daejeon, 305-353, South Korea. 3Department of Fuel Cells, Dongjin Semichem,472-2 Gaja, Seoku, Incheon,

404-250, Korea 4Department of Materials Science and Engineering, Chungju National

University,50 Daehak-ro, Chungju, Chungbuk 380-702, Korea 5School of Mechanical Engineering, Inha University253 Yonghyun, Namgu,

Incheon, 402-751, Korea 6Department of Applied Chemistry, Konkuk University,322 Danwol, Chungju,

Chungbuk 380-701, Korea

[email protected]

Abstract

A Co-based electrocatalysts were fabricated by sputter deposition on CNT/CP and heat treatment in an NH3 environment. A sample of Co-based electrocatalyst treated at 850°C showed more current density compared with samples treated at other temperatures. It is not possible to form sufficient ligands between Co and CNT/CP at lower heat treatment temperature, while it will degrade the performance of Co-based electrocatalysts thermally at higher heat treatment temperature. Although the current density of a Co-based electrocatalyst is not as high as that of a Pt/C electrocatalyst yet, this approach give us challenge to replace non-precious metal electrodes in the PEMFC.

Keywords: Cobalt, CNT, PEMFC, electrocatalyst, sputtering


- 212-

Study of Inhibiting effect of NaCl on the

Biodegradability of Dairy Wastes

K. DERBAL, H. BRIHI,B. KHEREDDINE, R. BOUBECHOU, M.

BENCHEIKH-LEHOCINE, A. H.MENEIAI

Laboratoire de l’Ingénierie des Procédés de l’Environnement (LIPE),

Département de Chimie Industrielle,Faculté des Sciences de l’Ingénieur,

Université Mentouri de Constantine, Algeria.

[email protected]

Abstract

The main objective of this work is to understand the inhibitory effect of NaCl on the biodegradability of selected dairy rejection. In this study a series of NaCl concentrations were used: 0.0, 0.64, 1.59, 3.18; 6.35; 19.10. The study was initiated by characterization of dairy waste and sludge waste used. This characterization shows that the dairy waste COD was 106382.97 mg /l, which requires the application of a treatment prior to discharge into the media receiver. On the percentage in volatile, the analysis shows that it is very rich in biodegradable mater (87.52% in TVS). This result encourages the application of an anaerobic biological treatment method. To properly estimate the energetic power of the method, the study of the biodegradability of a dairy waste in mesophilic phase was performed. After an incubation period (over 45 days), the liquid phase of the residue obtained was characterized. The analysis was achieved through the determination of various parameters such as pH, total solids (TS), total volatile solids (TVS), the partial (TA) and total (TAC) alkalinity, the soluble ant total chemical oxygen demand (CODs) and (CODt), ammonia nitrogen (NH4 +), organic nitrogen (Norg) and total phosphorus (Pt). For pH, the pH values are between 6.88 and 8.42 in all reactors considered. Usually these values are acceptable and promoted the stability of the anaerobic digestion process. Noting also that the elimination rate of TVS is 68.27% in some cases, what is acceptable in this type of treatment. The results also show that increasing the concentration of NaCl added increases the value of the TVFA/TV from 0.12 to 0.76 and that for concentrations of 0.0 and 19.10 g / l NaCl, respectively, with the exception of reactor Rac -31 where the value of the TVFA/TV is greater than unity, corresponding to the concentration of NaCl added equal to 6.35 g /l. Values the removal efficiencies of ammonia nitrogen, organic nitrogen and phosphorus are between 96-99, 60-90 and 80-90% respectively. Similarly, the volume and composition of biogas are important for the control and monitoring of the process of anaerobic digestion. The results show that the cumulative volume of biogas produced is high where it lie in the interval: 1501.9 - 1643.9 ml. So the total cumulative volume of biogas produced is due to the presence of the substrate (dairy waste) where it represents a percentage between 82.42 and 83.94% of the total volume of produced biogas. Regarding biomethane production volume is important as it can in some cases reach 700 ml. The percentage of methane in the biogas varied between 46.45 and 58.16 for an inoculum substrate ratio (ISR) = 0.81 and added NaCl concentrations between 0.00 and 19.10 g / l respectively..

Keywords: Dairy waste, biodegradability, mesophilic, biogas; sludge inhibition, NaCl.


- 213-

Effect of hydrogen addition on methane/air auto

ignition under HCCI engine combustion mode

Boussad BOUMEDDANE

Department of mechanical engineering, Faculty of Technology, University Saad

Dahleb BLIDA, BP 270,route de Soumaa, 09000 BLIDA, Algeria.

[email protected]

Abstract

Hydrogen addition to methane/air has a significant effect on the auto-ignition onset of the mixture under HCCI engine operating conditions. The ignition delay considered as the time between the inlet valve closing IVC and the beginning of the mixture ignition, depends on the amount of hydrogen injected into the engine. Indeed the addition of hydrogen reduces the ignition delay and increases the ignition advance. For high hydrogen rates in the mixture, the reaction becomes detonating and high levels of pressure and temperatures can be achieved in these case. For rich mixtures, reducing the proportion of hydrogen and the initial temperature at the start of compression stroke is necessary to avoid the appearance of the detonation regime. The Combustion in this case becomes detonative and harmful to the engine. Unlike rich mixtures, lean mixtures behave in terms of ignition in a contrary manner. Thereby to control the combustion and achieve ignition near the top dead center we must increase the amount of hydrogen injected into the engine. At cold start, we can add significant proportions of hydrogen to facilitate the engine start and subsequently reduce its proportion in the mixture when the temperature of walls become sufficient to provide additional thermal effect to facilitate the auto ignition of the mixture.

Keywords: HCCI engine, hydrogen addition, auto ignition, combustion, chemical kinetics


- 214-

Chemistry and Mineralogy studies of

PM10Atmospheric Aerosols in the Gulf of Gabès,

South Tunisia

Dalila TAIEB and Ammar BEN BRAHIM

Applied Thermodynamics Research Unit (99/UR/11-21), National Engineering

School of Gabès, Rue Omar Ibn-Elkhattab 6029 Gabès, Tunisia, Gabès

University.

[email protected]

Abstract

This study provides a comprehensive report on mass concentrations, Chemical composition and mineralogy characterizations of PM10 atmospheric aerosols in the Gulf of Gabès, in south Tunisia.

Data were collected at 18 locations (sample points in urban zones with industrial influence). Principally, they were located near the industrial complex (within a distance of 1000-6000 meters). At each sample point, sulphur dioxide PM10 was measured, with a mobile monitoring unit equipped with real-time analysers, which generated a mean value of each pollutant for an interval of 15 min. The duration of this measurement campaign was 20 days successive in 2007.

In this study, statistical and geostatistical techniques were used to estimate PM10 atmospheric pollution throughout the experimental area. After analysing data and obtaining a good variogram, multivariate data analysis, cartography via ordinary kriging, , was used to estimate PM10 concentration at unsampled locations.

The result shows that PM10 samples were enriched metal elements specially Fe and Cd. In addition the minerals phases identified in the samples were Calcite, Gypsum and Dolmite.

Keywords: Dust; industrial pollution, Metals; Mineralogy; Golf of Gabès


- 215-

Numerical study of a fuel cell coupled to metal-

hydrogen reactor

ZOMMIT Insaf1, DHAOU Houcine

1, 2, JEMNI Abdelmajid

1

1 Laboratoire des Etudes des systèmes Thermiques et Energétiques (LESTE),

ENIM, Avenue Ibn El Jazzar, Route de Kairouan, 5019 Monastir, Tunisia. 2 Faculté des Sciences de Monastir, Rue de Kairouan 5000, Département de

physique, Tunisia.

[email protected]

Abstract

Hydrogen is regarded today as an energy vector, since it is produced from renewable energy sources or nuclear ones. One of its major privileges is that it can be storable in large quantities for industrial or stationary use and have a high energy density. Coupled to a fuel cell, hydrogen technology offers new options for powering fuel cells. The present paper studies the coupling of the fuel cell and reactors metal-hydrogen. This system converts the input of heat and mass in a combustion area to generate electricity. A parametric study is carried out for LaNi5 and Mg2Ni alloys for various temperatures and various parameters, in order to determine the operating time of the fuel cell and its effectiveness and performance. We solved numerically the system of equations representing the transfer of heat and mass in the reactor then its coupling with the fuel cell.

Keywords: Metal hydride, fuel cell, Hydrogen, heat transfer


- 216-

Utilization of waste Tunisian palm tree date as low-

cost adsorbent for the removal of dyes from textile

S. GUIZA, K. GHILOUFI, M. BAGANE

Department of Chemical Engineering Process,.National Engineering School of

Gabés, Tunisia.

[email protected]

Abstract

The removal of dyes such, as methylene blue and Congo red, from an aqueous solution is studied by adsorption Tunisian palm tree date. The equilibrium isotherm for each dye-adsorbent system was determined. The experimental results have been fitted with Langmuir and Freundlich isotherms. The maximum adsorption capacities of palm tree date are found to be 200 and 90 mg/g at dyes of methylene blue and Congo red, respectively. A comparative cost study, based on the adsorption capacity alone, has shown that the costs of the required adsorbent are 1.1%, and 1, 8%, respectively, compared with the case of commercial granular activated carbon. The Gibb‟s free energy values obtained confirm that the process is feasible and spontaneous ∆G< 0. The negative values of ∆H indicate that an exothermic chemisorption toke place. The negative values of ∆S suggest that the randomness decreases after adsorption.

Keywords: Tunisian palm tree, Textile


- 217-

Development of hybrid Photovoltaic-fuel cell system

for stand-alone application

Djamila REKIOUA, Nabila BETTAR

Department of Electrical Engineering, Laboratory LTII, University of Bejaia,

06000, Algeria.

[email protected]

Abstract

In this paper we present firstly the different hybrid systems with fuel cell. Then, the study is given with an hybrid fuel cell- photovoltaic generator. The role of this system is the production of electricity without interruption in remote areas. It consists generally of a photovoltaic generator (PV), an alkaline water electrolyzer, a storage gas tank, a proton exchange membrane fuel cell (PEMFC), and power conditioning units (PCU) to manage the system operation of the hybrid system. Different topologies are competing for an optimal design of the Hybrid Photovoltaic-Electrolyzer-Fuel cell System. The studied system is proposed. PV subsystem work as a primary source, converting solar irradiation into electricity that is given to a DC bus. The second working subsystem is the electrolyzer which produces hydrogen and oxygen from water as a result of an electrochemical process. When there is an excess of solar generation available, the electrolyzer is turned on to begin producing Hydrogen which is sent to a storage tank. The produced Hydrogen is used by the third working subsystem (the fuel cell stack) which produces electrical energy to supply the DC bus. The modelisation of the global system is given and the obtained results are presented and discussed.

Keywords: Fuel cell (FC), Photovoltaic (PV) , Hybrid Power system (HPS), Fuel cell

(FC), power management.


- 218-

Electrodialysis Performancesand Environmental

Issue

Salah FRIOUI1, Rabah OUMEDDOUR

1, Stella LACOUR

2,

1Laboratoire LAIGM, Université 8 mai 1945 de Guelma B.P. 401, 24000

Algérie, IEM Université Montpellier 2 CC 047 Place Eugène Bataillon 34095

Montpellier Cedex 5- France. 2Laboratoire LAIGM, Université 8 mai 1945 de Guelma B.P. 401, 24000

Algérie.

[email protected]

Abstract

The subject of this study is to find the efficient heavy metals recovery and separation from industrial effluents in two different synthetic binary solutions of soluble Ag(I)-Zn(II) and Cd(II)- Cu(II) in presence of EDTA as a complexing agent. This work is achieved by the electrodialysis technique under several and various conditions to allow water recycling preserve the nature and the environment and save energy. In this work, attention was paid to examining the recovery efficiency of two binary complexed solutions under optimum operating conditions. The performance parameters of interest of the ED were pH‟s feed, feed flow rates and voltage applied. Once these optimum operating conditions for the solution of Ag(I)-Zn(II)-EDTA are determined, a second demineralisation of the solution Cd(II)-Cu(II)-EDTA is achieved with high performance but some troubles with MEC membranes are observed. Although this technical problem, the experimental results shows that electrodialysis technique is performant and selective at adjusted pH nearly to 7, applied voltage of 20 volts and flow rate of the feed at 100 mL/min for a concentration of 10-3 eq/L. Also, experiments on ED in presence of EDTA proved that the separation of metals by electroextraction technique is much better appreciated by the scientific and industries communities than the other techniques applied in this field. This is due to its better selectivity, use of clean energy (electricity) and the recovered metals can be, in major cases, recycled and directly reused by manufacturers. Also, in this case the complexant is simply recovered by pH adjustment according to the diagram speciation and the recycled water obtained after demineralization is neutral and can be directly used for other purpose. According to the results obtained and energy requirements related in literature for this type of treatment, the ED cost of demineralisation may be, certainly one day, close to competing technologies the treatment of industrial effluents rich in heavy metals. The most beautiful of all this, the ED can be considered as a green and a friendly environment technology.

Keywords: Effluent, Complexant, Environment, Heavy metals, Recovery,

Demineralisation, Electrodialysis, Recycling.


- 219-

Production and characterization of biodiesel from

allamanda cathertica oil

EGWIM, EVANS. C. and IBRAHIM, Z.A.

Biochemistry department, federal university of technology, p.m.b 65, minna,

niger, state. Nigeria.

[email protected]

Abstract

The gradual depletion of world petroleum reserves and the impact of environmental pollution due to increasing exhaust emissions, there is an urgent need to develop alternative energy resources, such as biodiesel fuel. Vegetable oil is a promising feedstock because it has several advantages; it is renewable and environmental friendly. The present study involves oil extraction from allamanda cathertica seed (Allamanda), conversion of the oil into biodiesel and the characterization of the methyl ester. Transesterification of the oil from allamanda cathertica was conducted using methanol and NaOH as catalyst, using a range of reaction temperatures (45, 50, 55, 60 and 65°C ) and different rates of stirring. Result showed that allamanda seed produced 54% oil yield using mechanical extraction. The yield of biodiesel with respect to temperature were 63, 88, 94, 46 and 20% respectively. Characterization of the biodiesel produced from this study compared favorably with the ASTM standards, viscosity 5.4, flash point 115°C, refractive index 1.4756 and energy value 35.0MJ/L. The GCMS analysis of the methyl ester showed a range of 10 different methyl esters which includes hexadecanoic acid (24%), linoleic acid (14.8%), 13-Decosenoic acid (35.3%), 9-Octadecanoic acid (13.5%). The work concludes that allamanda oil could be a good and alternative feedstock to the edible feedstocks currently in use for biodiesel production.

Keywords: Biodiesel, non-edible feed stock, Allamanda oil, Environmental friendly


- 220-

A novel method for improving the catalytic activity

of carbon supported Co-B catalyst for hydrogen

generation through hydrolysis of NaBH4

Ferhat BAYDAROGLU1, Ercan ÖZDEMIR

2 and Aydin HASIMOGLU

1

1 Gebze Instute of Technology, Department of Chemisrty, 41400, Kocaeli,

Turkey. 2 Gebze Instute of Technology, Clean Energy & Nanotechnology Reseach

Center 41400, Kocaeli, Turkey.

[email protected]

Abstract

A novel method for preperation of carbon supported cobalt boride catalysts were developed for hydrogen generation from catalytic hydrolysis of NaBH4 solution. The activated carbon and carbon black supported catalysts prepared by “pre-reduction – impregnation method“ were found to be much more active than those prepared by conventional “impregnation – reduction method” inspite of the same Co content. The effects of NaOH concentration (1-15 wt%), NaBH4 concentration (5-20 wt%) and reaction temperature (25-40 °C) on the performance of the most active catalyst was investigated. A maximum hydrogen generation rate was achieved using carbon black supported Co-B, which showed lower activation energy of 40.914 kJ mol−1. The results showed that this catalyst can be used in a hydrogen generator for mobile applications such as PEMFC systems due to its high catalytic activity and simple preparation method.

Keywords: Hydrogen generation, sodium borohydride, supported Co catalyst, hydrolysis


- 221-

Numerical Simulation of Heat and Mass Transfer

during Biomass Pyrolysis in a Packed bed Reactor

Mohamed Ali MASMOUDI 1, Melik SAHRAOUI

2, Najla GRIOUI

1

and Kamel HALOUANI 1

1METS, ENIS– IPEIS, University of Sfax, Route Menzel Chaker km 0,5 - B.P.

1172, 3018, Sfax – Tunisia. 2LASMAP– EPT, University of Carthage, La Marsa – Tunisia.

[email protected]

Abstract

Biomass upgrading for different energy carriers is being explored via several processes. As a part of the developed technologies, gasification is used to convert biomass materials into a gaseous mixture consisting mainly of carbon monoxide and hydrogen. Gasification process involves biomass pyrolysis as first step in the conversion process. In this paper, biomass pyrolysis is studied in a packed bed. A numerical model was developed based on the conservation equations and the kinetic data in order to simulate the pyrolysis process. The model is used to predict the temperature and species fields within the bed. The numerical model can simulate the degradation process at different operational parameters including fuel moisture, reactor dimensions, final process temperature, etc. It can be also extended to simulate pyrolysis as the first stage in a fixed bed gasification reactor.

Keywords: Biomass, pyrolysis, heat transfer, porous media, modeling


- 223-

Study of optical and structural parameters of

LPCVD silicon oxynitride layers for solar cells

applications

Bessem Kaghouche1, Farida Mansour

1

1 LEMEAMED Laboratory, Department of Electronics, University Mentouri,

Constantine, 25000, Algeria.

[email protected]

Abstract

Silicon oxynitride (SiOxNy) films were deposited by low pressure chemical vapour deposition (LPCVD) technique at temperature of 8500C from a mixture of dichlorosilane (SiH2C12), nitrous oxide (N2O) and ammonia (NH3). Single crystal Si (100) wafers were used as substrates. The optical and structural properties of the elaborated layers were obtained using spectroscopic ellipsometry. The Bruggeman effective medium approximation (EMA) has been used to calculate the refractive index, films thicknesses and volume fractions for the phases. The superposition of experimental and theoretical curves showed a satisfactory agreement. After deduction of the optical parameters (refractive index and permittivity), we have simulated the technological elaboration and the electric behavior of the MIS structure (Aluminum-Oxynitride-Silicon) using ATHENA and ATLAS modules of TCAD-SILVACO software.

Keywords: Silicon Oxynitride, ellipsometry, EMA

- 224-


- 225-

Modelling, Simulation and

Control

‘MSC’

- 226-

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-MSC-9/P

- 227-

Improvement of the performances of the electronics

components using MATLAB / SIMULINK.

A.YOUSFI, A.BESRA, Y. BENLALLI, M.N .AMRANI, M.K .ZERMANI,

M.BOUAKKAZ

Physics Solid state Badly Ordered Theory and Applications,

Badji Mokhtar-Annaba University.

[email protected]

Abstract

Within the framework of the use of materials (single-crystal, polycrystalline, amorphous) for the exploitation of solar energy starting from the photovoltaic effect, one presented a contribution to the performance enhancement of the electronics components used in the energy transformation. The photovoltaic system allows us the exploitation of solar energy thanks to the cells photovoltaic which give us electrical energy. This study being in the form of a simulation of the various converters. Our study was based on the performance enhancement of the electronics components used in the energy transformation starting from the simulation of these components. Finally one confronted the results obtained with those of the theoretical study and they are agree.

Keywords: Inverter, Chopper, Gradator, Performance


- 228-

Computer Analysis Of The Inverter With Series-

Parallel Resonnance Circuit Applied To

Photovoltaic Energy

A.BESRA, A.YOUSFI,Y.BENLALI, M.K ZERMANI, A.RAZEM

and A.GASMI

Badji Mokhtar Annaba University (ALGERIA), BP 12 Annaba.

[email protected]

Abstract

Analysis, simulation results and experimental researches results of a modified inverter with series-parallel resonance circuit are inverted. The modification is obtained by introduction of a feedback circuit which greatly improves the dynamic behaviour of the inverter e.g. Feedback circuit make it possible for the inverter to work correctly also at an idle run.

Keywords: Commutation, resonance circuit, parallel-series, thyristor, inverter circuit,

electric drive, photovoltaic energy.

The Fourth International Renewable Energy Congress December 20-22, 2012 – Sousse, Tunisia IREC2012-MSC-11/O

- 229-

A transient study of coupled convection and

radiation using a mesoscopic approach

Raoudha CHAABANE, Faouzi ASKRI, Sassi Ben NASRALLAH

Laboratoire d’Etudes des Systèmes Thermiques et Energétiques, Ecole

Nationale d’Ingénieurs de Monastir-Avenue Ibn El Jazzar, 5019 Monastir,

Tunisie.

[email protected]

Abstract

In this paper, the unsteady combined natural convection radiation in a two dimensional differentially heated cavity containing an absorbing, emitting and scattering medium is discussed using Lattice Boltzmann Method- control volume finite element method (LBM-CVFEM). The paper is intended to address the physics of flow and heat transfer in such thermal incompressible flows. The results obtained are compared and validated against available results in literature. The vertical velocity in the horizontal mid-plane, the horizontal velocity in the vertical mid-plane, the isotherms and the streamlines are presented and analysed, finally the effect of radiation on convection is highlighted.

Keywords: LBM-CVFEM, Transient, radiation, natural convection; participating medium.


- 232-

Chaos and Bifurcation of DC-DC Buck Converter

Ahmad M. HARB Souhib M. HARB

Ahmad M. HARB is with Department of Energy Engineering, German

Jordanian University, Amman-Jordan, Souhib M. HARB is with the

Department of ECE, Texas A&M University, College Station, TX 77843.

[email protected]

Abstract

In this paper, chaos and bifurcation theory is applied to study the nonlinearity phenomenon in DC/DC Buck converter. A practical design for a DC/DC buck converter was considered in this study. By means of iteration mapping method, the nonlinearity of the DC-DC buck converter is studied. The results showed that having a well-designed buck converter as well as a feedback controller, the system does not exhibit any nonlinear phenomenon. To verify these results, a buck converter, with non-practical parameters, was also studied. In this case, the results showed bifurcation and then chaotic behavior for the output voltage and inductor current as the input voltage changes. A comparison between the two cases will be discussed in more details.

Keywords: DC/DC converter, buck converter, bifurcation, chaos, modern nonlinear

theory.


- 233-

Sliding mode control of multi-cells inverter applied

to an active power filter with unbalanced voltage

ROUABAH Boubakeur1, RAHMANI Lazhar

2

1University of Setif, Algeria.

2University of Setif, Algeria.

[email protected]

Abstract

This paper presents the sliding mode control of four-level three phase multi-cells voltage source inverter with flying capacitors, applied to shunt active power filter. In this work, after modeling of the hall system: Source-multi-cells inverter-no linear load, we have developed the sliding mode control for the active power filter to have a sinusoidal current and in phase with the input voltage and compensate the reactive power; the application of the instantaneous power is to regulate the DC voltage and the delayed signal cancellation (DSC) to compensate the unbalanced network voltage. The results obtained from Mathlab/Simulink in steady state show that the sliding mode control has the acceptable THD of grid current and the robustness against the parametric variations and unbalanced voltage.

Keywords: Multicellular inverter; active power filter; sliding mode control; delayed signal

cancellation (SDC).


- 235-

Identification of wind turbine blade defects using

airborne acoustic measurement and residual matrix

of principal component analysis

Abdelnasser ABOUHNIK, Alhussein ALBARBAR

Advanced Industrial Diagnostics Centre, Faculty of since & Engineering,

Manchester Metropolitan University.

[email protected]

Abstract

With increasing wind turbine size and cost, new thinking is required on methods to reduce maintenance cost, prevent wind turbine breakdown and reduce downtime. Microphones offer an inexpensive and non-contact method for monitoring the health of wind turbine blades. This paper presents a novel technique for analysing wind turbine air-borne acoustic signals for condition monitoring (CM) of wind turbine blades. It proposes the combination of crest factor (CF) and residual matrix of principal component analysis (PCA) for predictive maintenance and CM of wind turbine blades. PCA is used to decompose air-borne acoustic signals for both healthy blades and for a „crack‟ fault seeded into a single blade. The „cracks‟ consisted of a 3 mm wide 2 mm deep channel drilled into the blade, the channels were of four lengths 10mm, 20mm, 30mm and 40mm), about 50mm Close to the root of the blade. PCA was used to extract the residual matrix signals which contain information on all the wind turbine components contained in the airborne acoustic signal. The CF of the residual matrix was determined and turbine condition the faults were found based on comparing the CF amplitude with the base line (healthy) level. The results showed that applying the CF to the decomposed airborne acoustic signals is more effective than other statistical parameters. Hence it can be used for fault detection. Moreover the results showed that CF levels were very sensitive to wind turbine blade condition and the proposed approach is a promising technique because it successfully differentiated the signals from healthy wind turbine blades and wind turbine containing cracks in one blade.

Keywords: Residual matrix of principal component analysis (RMPCA), microphones,

airborne acoustic, wind turbine monitoring and blade cracks.


- 237-

Analysis and performance of a switched reluctance

generator for wind energy application

F.MESSAI, M.MAKHLOUF, H.BENALLA, K.NABTI

Department of Electrical Engineering, Faculty of Engineering Sciences,

Mentouri University of Constantine, Algeria.

[email protected]

Abstract

This paper traits the subject of the switched reluctance variable speed wind generator system for wind power applications. The studied machine is composed of switched reluctance generator, power converter and controller. The main elements were discussed. To study the of SRG accurately, according to the nonlinear inductance model, a nonlinear SRG model is built based on the electromagnetic field finite-element analysis (FEA).It also highlights the common type of converter and structure used for SRG in wind energy application and the control strategy too. The power converter can operate over a wide speed range. In addition this work analyzes the generator mode of the Switched Reluctance Machine in the direct coupling to the turbine shaft. The simulation results show how high the efficiency of the used strategy control is.

Keywords: Double Salient Switched Reluctance Generator (SRGDS), Wind Energy,

Direct-drive Wind Turbine, Power Electronic Converter.


- 238-

Smart Grid Technology for Better Integration of

Renewable Energy Resources

Dr. Ibrahem A. ELAGTAL and Abdussalam A. KHAMIS

Faculty of Engineering Technology - Hoon, Libya.

[email protected]

Abstract

Smart grid technology and its complex digitalized system is relatively a new concept in power systems. One of the potential advantages of this technology is its ability to make the connection of renewable resources into working electricity grids possible. This paper discusses two scenarios of implementing smart grid technology to facilitate integration of renewable energy into the Libyan electricity grid. The first scenario proposes some techniques that would play significant roles in connecting large-scale renewable energy plants into the Libyan national electricity grid. The second scenario discusses the roles that smart grid can play in order to support electrification services at distribution networks by supplying them with distributed generations. The validity of these two proposed scenarios are concluded in the end of the paper.

Keywords: Smart Grid, Renewable Energy, Distributed Generation.


- 239-

Transient Performance of Stand-alone

Inductiongenerator

Hussam M. El-KAFRAWI1, Mohamed S. BUAMUD

2

1The Higher technical institute for qualifying instructors, Elqubba, Libya.

2Benghazi University, Benghazi, Libya.

[email protected]

Abstract

This paper presents transient performance of a three phase self-excited induction generator (SEIG) under balanced and unbalanced conditions. An approach based on three-phase induction machine model is employed to derive dynamic equations of star-connected three-phase self-excited induction generator by using d-q variables in a stationary reference frame. Generator, capacitors, and load equations have been arranged to form the system model. The process of building up of the terminal voltage during self-excitation and during the recovery of the terminal voltage and stator current due to load changes are described. The model is also extended to study the generator behavior during balanced and unbalanced faults. Simulation results such as electromagnetic torque, stator currents, terminal voltage are plotted and discussed.

Keywords: Induction generator, self-excitation, modeling and simulation, fault analysis.


- 240-

Multi-objective generation scheduling using genetic-

based fuzzy mathematical programming technique

Abdellah DERGHAL and Noureddine GOLÉA

Electrical Engineering Department, Oum El Bouaghi,

University, Algeria.

[email protected]

Abstract

This paper presents a solution for multi-objective optimal power flow (OPF) problem via a genetic fuzzy formulation algorithm (GA-FMOPF). Fuzzy mathematical programming is used to represent objective functions with fuzzy parameters and uncertainties in constraints set, and GA is used to solve the reformulated FMOPF. An illustrative example is given to clarify the proposed method developed in this paper.

Keywords: OPF, FMOPF, Multi-objective Optimization, Fuzzy set theory, Genetic

Algorithm


- 241-

Thermosolutal natural convection and thermal

radiation inside a porous enclosure

Abdesslem JBARA, Abdelaziz NASR, Khalifa SLIMI

and Abdallah MHIMID

Energy and Thermal Systems Laboratory, National Engineering School of

Monastir,University of Monastir, Ibn El Jazzar Street 5019, Tunisia.

[email protected]

Abstract

Heat and mass transfer by double diffusive natural convection and thermal radiation inside a porous enclosure has been numerically investigated. A sensitivity study of fluid flow and heat and mass transfer to different controlling radiative parameters, such as the particular emissivity ε, the optical thickness τD, the single scattering albedo ω and the conduction-radiation parameter N, has been performed. The results indicate that the temperature and the axial velocity values are increased when ε and τD are increased or when ω and N are decreased. Moreover, the concentration values are decreased when ε and τD are increased or when ω and N are decreased.

Keywords: thermosolutal, porous media, radiative parametres


- 242-

Study of Entropy Generation Inside a Porous

Enclosure

Abdesslem JBARA, Amel FARHAT, Khalifa SLIMI

and Abdallah MHIMID

Energy and Thermal Systems Laboratory, National Engineering School of

Monastir,University of Monastir, Ibn El Jazzar Street 5019, Tunisia.

[email protected]

Abstract

Entropy generation problem for unsteady natural convection and thermal radiation in a vertical porous enclosure has been performed numerically. A space-time variations study is presented for the entropy generation Sgen and a parametric study based on the influence of radiatives parameters on Sgen evolution is also presented and discussed. Results show that, Sgen values rise when there is an increase in ε or

D values and it decreases with the increase of ω or N values.

Keywords: Entropy generation; porous enclosure; thermal radiation; unsteady natural

convection; finite volume method


- 243-

Combined Cycle for power generation and low

temperature refrigeration using low temperature

heat sources

Vijay Chauhan1, P. Anil Kishan

1, SateeshGedupudi

2

1 School of Engineering, Indian Institute of Technology Mandi, Himachal

Pradesh – 175 001, India. 2 Mukesh Patel School of Technology Management and Engineering,

NMIMS, Mumbai – 400 056, India.

[email protected]

Abstract

A combined refrigeration/power cycle, which uses ammonia-water as the working fluid, is proposed which combines Rankine and Vapour Absorption cycles with an dvantage of varying refrigeration capacity to power output ratio. The study investigates the usage of cycle using low temperature heat sources.Results of parametric analysis done are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using genetic algorithm for different ambient temperatures are also presented. The cycle shows good potential for obtaining low temperature refrigeration and power generation.

Keywords: ammonia- water, exergy, refrigeration, solar energy.


- 244-

3D study of heat and fluid flow of air filling

containers partially heated from below

Sihem MELLAH, Nader BEN-CHEIKH, Brahim BEN-BEYA, Taieb LILI

Déparement de physique, Faculté des science de tunis, Campus universitaire

2092, El Manar II, TUNISIA.

[email protected]

Abstract

This work addresses a numerical approach based on the finite volume method and a full multi-grid technique to study three-dimensional flow structures and heat transfer rates in partially heated cubical enclosures. Numerical solutions are generated for representative values of the controlling Rayleigh number inside the range 103≤ Ra ≤108. The heating occurs with a heated strip placed on the bottom horizontal wall of the enclosure. Results are presented in the form of projection of flow lines and isotherms plots as well as the variation of the Nusselt number and the average temperature at the heat source surface.

Keywords: Fortran, temperature, fluid


- 245-

Aspect Ratio effect on Drying of Saturated

Deformable Porous Media using the Lattice

Boltzmann Method

El ABRACH Hussein, DHAHRI Hacen and MHIMID Abdallah

National school of Engineers, Monastir University, Ibn Eljazzar Street,

Monastir, 5019, Tunisia.Laboratory of Thermal and Energy Systems Studies,

Ibn Eljazzar Street, City Monastir, 5019, Tunisia.

[email protected]

Abstract

A numerical analysis is made of drying of deformable porous media using Lattice Boltzmann method (LBM). The physical model used for simulation is an isotropic deformable porous media saturated with two phases (solid and liquid). Walls of the sample are maintained to a convective heat flux. The water is evaporated via the top and bottom walls of the sample. The liquid flow is induced by a pressure gradient basing on the Darcy model. The deformation of the solid phase is deduced from the principle momentum conservations based on the Darcy-Brikmann extended model coupled to the Biot theory. The model for the energy transport was based on the local thermal equilibrium assumption, between the liquid and the solid phases. A omprehensive analysis of the influence of the aspect ratio on macroscopic fields is investigated throughout this work.

Keywords: Deformable, Porous medium, heat and mass transfers, LBM


- 246-

Dual source heat pump: modeling and simulation on

TRNSYS

R.CHARGUI*, a, H.SAMMOUDA

a, A.FARHAT

b

a Laboratoire d’Energie et de Matériaux (LR11ES34), Université de Sousse,

ESSTHSousse, Rue Abbassi Lamine, 4011, HSousse-Tunisia. b Centre National de Recherché et des Technologies de l’Energie (CNRTE),

PB 95, Hammam Lif 2015 Tunisia.

[email protected]

Abstract

Energy consumption in residential buildings has gained an increasing interest the latest years due to the rising demand for efficient energy use and higher comfort standards. The main objective of the present study is to investigate an application of heating and cooling of a house by using very abundant and easily accessible sources. This work highlights results on geothermal heat pump in heating and cooling mode. We present the modeling and the mathematical description of the heat pump on TRNSYS model by using HVAC technique. As well as the results of the simulation of the heat pump, such as the COP, consumed power, and delivered power by using the Tunisian climate. The system analysis focuses particularly on the influence of internal and geothermal gains of the heating (cooling) system operation and the thermal comfort of the house. Furthermore, the influence of the gain performance of the heating (cooling) system is examined. The results may provide useful insights into the relations between thermodynamics and economics.

Keywords: Coefficient of performance; Power; Dual source heat pump; Cooling system;

Heating system; TRNSYS.


- 247-

Numerical Simulation of Turbulent Two-phase Free

Surface Flows

Nawel KHALDI 1, Hatem MHIRI

1, 2, Philippe BOURNOT

3

1 Unité de thermique et de thermodynamique des procédés industriels,

Monastir, Tunisia. 2 Ecole Nationale d’Ingénieurs de Monastir, Monastir, Tunisia.

3 Equipe IMFT, Institut de Mécanique de Marseille, Marseille, France.

[email protected]

Abstract

In this work, we propose a numerical study for a turbulent two-phase free surface flow involving an incompressible liquid and a compressible gas and taking into account the surface tension effects. The simulations were carried out using Fluent 6.3 with three dimensional meshes. The aim was to produce a predictive hydrodynamic model for a turbulent two-phase free surface flow, which may become the basis for convection heat transfer analysis. The air/water interface was modeled with the Volume of Fluid (VOF) method. Prediction of the free surface is heavily influenced by the quality of the mesh. The numerical results prove that better prediction of the free surface is obtained with grid adaptation and a sharper free surface position is obtained with time step adaptation. The k-epsilon turbulence model gives an improved velocity profile prediction. Fluid heights predicted by the CFD agree well with those measured experimentally.

Keywords: Two-phase flow, free surface, turbulent, CFD, VOF


- 248-

Robust output voltage regulation and unity power

factor with Sliding Mode Control

Abdelhalim KESSAL, Lazhar RAHMANI

Laboratory of Automatic, Faculty of Technology, University of Setif,

19000, ALGERIA.

[email protected]

Abstract

The regulation by sliding modes is especially recognized for its qualities of robustness and dynamic response. This paper will briefly point out the principles of the regulation by sliding mode as well as the extension of those to the continuous adjustment of the output voltage of a rectifier in cascade with a chopper and the improvement of the power-factor at the entry. Based on the choice of the sliding surface, various fashions of control are studied. Accordingly, a proposed sliding surface utilizing all the variables of state will be used, thus improving the performances of the system in terms of robustness and dynamic response. Real-time implementation is performed on an experimental test bench using a rapid prototyping tool. Results show that the proposed controller gives better performances under large load disturbance and plant uncertainties.

Keywords: Power factor correction, boost converter, sliding mode control


- 250-

Modeling and Control of a low Pressure Discharge

Lamp used for Ultraviolet Radiations Water

Disinfection

Messai Tlili1, CHAMMAM Abdeljalil

1, SELLAMI Anis

2

1Higher School of Sciences and Technology

of Tunis-ESSTT. 2Research Unit C3S, ESSTT Tunis.

[email protected]

Abstract

In this paper, we present the modeling and control of a low pressure discharge lamp, used for ultraviolet radiations water disinfection, as the most important component of a plasma reactor. The found non linear model relates the current to the conductivity of the lamp. The used control approach is based on the concept of variable structure systems with sliding mode in discrete time for non linear systems. Reliable results are given to show the interest of the sliding mode control of complex physical systems and robustness of this control technique to some classes of parametric variations and external disturbances.

Keywords: Low pressure discharge lamp, particle swarm optimization, sliding mode

control, discrete time.


- 251-

Application of the Coordinated Voltage Control

Technique to the Tunisian Distribution Network

Using the Virtual Power Plant Approach

Maher Soyah1, Ahmed Rami Abdelli

2, Jalel Ben Hadj Slama

3,

Khadija Ben Kilani4

1Tunisian Company of Electricity and Gas.

2National Engineering School of Tunis.

3National Engineering School of Sousse. 4National Engineering School of Tunis.

[email protected]

Abstract

For political, economic and environmental reasons, distribution networks architectures change with the integration of high amounts of Distributed Generation (DG). This affects the static stability of the grid and leads to several problems especially those related to voltage. This paper shows negative impacts of DG‟s integration in the voltage profile of the Tunisian primary distribution network. To contribute to face them, the Coordinated Voltage Control (CVC) technique using the Virtual Power Plant (VPP) approach was implemented and applied to a test network in the south suburbs of Tunis. Simulation results show that the adapted solution helps to provide acceptable voltages in all buses, even with a large number of DG units.

Keywords: Distributed generation, coordinated voltage control,virtual power plant,

Tunisian distribution network.


- 252-

Automated Cleaning System for Street Light PV

Solar Panel

FALAH Mustafa1, Abd Salam AL-AMMRI

2, Areej Ghazi

3

1,3Department of Mechanical Engineering, Baghdad University. 2Solar Energy Research Center, Sciences and Technologies

Ministry, Iraq.

[email protected]

Abstract

This paper deals with the design and execution of a Self cleaning system for the street light solar panel. The proposed solar panel cleaning system ensures the optimization of the conversion of solar energy into electricity by removing dirt and other impurities from the surface of the solar panel. It is simple, light weight, slight to maintain, portable, withstand the environment; low-cost, long life, takes its power from the battery of the solar panel, and is operated automatically, by a remote control. The operation of the experimental model of the device is based on a DC motor intelligently controlled by a dedicated drive unit that moves a cleaning head of the panel upwards and downwards with and without using spraying system to increase the efficiency of the cleaning. The performance and characteristics of the self-cleaning system are experimentally analyzed.

Keywords: Design, Dust, PV, Performance, Self Cleaning


- 253-

Numerical Study of the Effect of Medium Capacity

with Chemical Heterogeneity on the Reactive

Dispersion in Porous Media

K. KAABECHE-DJERAFI, S. SEMRA, N. BENDJABALLAH-LALAOUI

Department of Industrial Chemistry, University Mentouri of Constantine

(UMC), BP 325, Route Ain El Bey, 25017 Constantine, Algeria

[email protected]

Abstract

This study investigated the influence of medium capacity on the relation between linear adsorbed solute dispersion and chemical heterogeneity at laboratory scale in porous media. Following the approach of continuous media and taking into account the discrete chemical heterogeneity distribution of the adsorbate, we have developed a model of adsorption in a fixed bed by introducing a new parameter quantifying the chemical heterogeneity. Highlighting the influence of heterogeneity on the breakthrough curve required the resolution of the advection-dispersion equation obtained from the modeling. A numerical method is developed using a finite volume method for the discretization of this equation, very effective in our case, despite the introduction of a probability distribution, which is the distribution of chemical heterogeneity, to resolve the partial differential equation. Numerical results show an important effect of medium capacity with chemical heterogeneity on the spread of the breakthrough curve. The more intense capacity is, the more important solute dispersion is.

Keywords: adsorption, chemical heterogeneity, dispersion, fixed bed, porous media.


- 254-

A Simple Tracking System to Monitor Solar

Receivers and PV Panels

H. BENTAHER1,2

, H. KAICH2, N. AYADI

3, A. MAALEJ

1

and U. LEMMER3

1Electro-Mechanical Systems Laboratory (LASEM),

School of Engineers of Sfax. 2Higher Institute of Industrial Systems Gabès. 3Karlsruhe Technical University – Germany.

[email protected]

Abstract

The solar tracking systems are very interesting part of a solar installation. If they are optional in flat receivers, they are a master part in concentrating ones. A simple tracking system was locally constructed, tested and optimized. Good agreement was recorded between the analytical optimization results and the experimental ones. These results are useful for the construction of new sun trackers.

Keywords: Tracking system, photo-resistor, photovoltaic, parabolic concentrators


- 255-

Improvement of Power System Transient Stability

Using Resistive-Type Fault Current Limiters SFCL

Sabir MESSALTI1, Fares ZITOUNI

2, Issam GRICHE

2

1University of M’sila, Faculty of Technology, Algeria.

2University of Setif, Faculty of Technology, Setif, Algeria.

[email protected]

Abstract

This paper shows the modeling and the effectiveness of superconducting fault current limiter (SFCL) for transient stability improvement of power systems. SFCL is a device that limits the fault current by generating impedance when a fault occurs. SFCL installed in series with transmission lines can be just operated during the period from the fault occurrence to the fault clearing , the effect of SFCL has been investigated to have a higher benefits for power system . In the present work, modification of the admittance matrix method is used for modeling of SFCL, Critical Clearing Time (CCT) has been used as an index for evaluated transient stability. The transient stability is assessed by the criterion of relative rotor angles, using Runge-Kutta method. The effectiveness of the proposed method is tested on the WSCC3 nine-bus system applied to the case of three-phase short circuit fault in one transmission line.

Keywords: Critical Clearing Time CCT, Runge-Kutta method, superconducting current

limiter SFCL, Transient stability.


- 256-

Simulation Tool for Energetic Analysis of Mobile

Photovoltaic Systems

Tina GIUSEPPE MARCO , Cristina VENTURA

Dipartimento di Ingegneria Elettrica, Elettronica e Informatica

University of Catania, Viale Andrea Doria n. 6,

95125, Catania, Italy.

[email protected]

Abstract

High autonomy is an important goal of many mobile systems, it can be achieved in three ways: reducing energy consumption, increasing the capacity of batteries and replenishing battery energy over time. Another possibility comes from using an on-board generating system: in this context photovoltaic system (PVS) is a real possibility. To model the whole system and to evaluate its energy performance, a Simulink model in Matlab environment has been developed. Meteorological variables (radiance and ambient temperature) are essential input to estimate the power production of a PVS. In this simulator, measured or forecast values of radiation and temperature can be considered. A mobile robot is used as test-bed. Once that the path followed by robot is known, the Simulink tool calculates both the energy produced by PVS and robot energy consumption. Different scenarios concerning the optimization of the PV production have been considered and simulated. This model can become a very helpful tool to estimate the power production of PVS applied to any mobile system in such a way not only to optimize the energy performances but also to refine the sizing of the PVS.

Keywords: simulator, photovoltaic, mobile system


- 257-

Design and Iimplementation Two Axes Sun Steps-

Tracking System

Falah MUSTAFA1, Nabeel AL-SAHIB

2, Ayad KWAD

3

1,3Al-Khawarizmi College of Engineering, Baghdad University , Baghdad.

2 Solar Energy Research Center, Renewable energy directorate, Ministry of

Sciences and Technologies, Baghdad, Iraq.

[email protected]

Abstract

This work is aimed to design and build a complete tracking system with real standards including the mechanical structure, electronic controller circuit based on PIC, robust program that can be adapted according to the location and the season that it works within in proportion to estimate the benefit (so one can chose the way of tracking with either a constant time or with a constant number of moves in a day), and ingenious strategy in tracking. It used the astronomical equation to calculate the altitude and azimuth angles for two axes tracking system to determine the sun position over the sky precisely at any time during the day for years including the leap years in every four year period with different weather conditions like partial cloudy weather for a part of the day or of dusty weather for periods of the day to avoid the loss of sun path as a result of partial cloudy weather for a part of the day or of dusty weather for periods of the day, in which the Gulf region is distinguished.

Keywords: Active tracking system, Open loop tracking system Sun tracking system, ,

standalone tracking system, two axes tracking


- 258-

Speed Sensor Less using Sliding Mode Observers of

Stator Currents and Rotor Flux for Induction Motor

Chiheb BEN REGAYA, Fethi FARHANI, Abderrahmen ZAAFOURI,

Abdelkader CHAARI

University of Tunis Unit C3S, High School of Sciences and Techniques of

Tunis (ESSTT), 5 Av. Taha Hussein, BP 56, 1008 Tunis, Tunisia.

[email protected]

Abstract

In order to eliminate the speed sensor on field-oriented control for induction motor drive, we can use a speed estimator, or it is unable to cancel the estimation error where the model parameters are uncertainties. In this paper we propose a control scheme using sliding mode observer. The design includes rotor flux observer using the sliding mode technique, rotor speed estimation from measured stator terminal voltages and currents. The estimated speed is used as feedback in an indirect vector control system. Several tests were performed to evaluate the performance of the observer methods.

Keywords: Sliding mode observer, Induction motor, Vector control, Speed sensor less,

Flux observer.


- 260-

A Multi Agent Petri Nets Model based Strategy for

Electric Power Management in Microgrids

Tarek JELLAD , Khaled TAOUIL , Zied CHTOUROU

Unit of Machine Control and Power Grid (CMERP) -ENIS-Tunisia.

[email protected]

Abstract

Site connection to the grid is not always feasible due to economic viability of the investment or forgeographical reasons. Renewables are good alternatives in such situations to power geographically isolatedsites. Different renewable energy source are then deployed throughout the site. A microgrid is then buildthrough the inter connection of these different sources. The energy produced by these several distributed energyresources (DERs) can be used to power the entire load of the site. In the absence of possibility of connection tothe grid, the microgrid operates in the islanded mode operates. Renewable energy sources are intermittent anddepend largely on climatic conditions. In periods of high consumption fuel generators are used resulting in anadditional cost of production. Sharing energy and optimizing energy exchanges between DERs can anticipatepeak consumption and contributes to the energy balance of the microgrid. Loss of energy produced by renewableenergy sources can then be minimized. We propose in this paper a strategy for managing energy exchangeswithin a microgrid. The proposed solution is based on the use of multi-agent systems (MAS) and Petri nets. Ourstrategy has been validated on the basis of a dynamic model for the simulation and optimization of powerexchanges between different DERs.

Keywords: Microgrid, Microgrid Energy management systems (MEMS), Multi-agent

system (MAS), Petri Nets.


- 261-

A second order modelling of a stably stratified

turbulence submitted to a non vertical shear

Lamia THAMRI NAFFOUTI 1, Mounir BOUZAIANE

1,2

and Taieb LILI 1

1 Laboratoire de Mécanique des Fluides, Département de Physique,

Faculté des Sciences de Tunis. 2 Département de Physique, Faculté des Sciences de Bizerte.

[email protected]

Abstract

Second order modelling remains one of the more import approach to understand geophysical turbulent.In this work, the evolution of homogeneous stably stratified turbulence submitted to a non-vertical shear is studied using second-order closure models. Two cases of turbulent flows are considered. Firstly, the case of a purely horizontal shear is considered. In this case, the evolution of the turbulence is studied according to the Richardson number Ri which is varied from 0.2 to 3.0 when other parameters are kept constant. In the second case, two components of shear are present. The turbulence is submitted to a vertical component and a horizontal component . In this case, we study the influence of shear inclination angle θ on the evolution of turbulence. In both cases, we are referred respectively to the recent direct numerical simulations of Jacobitz (2002 J. Turbulence 3 055) and Jacobitz and Sarkar (1998 Phys. Fluids 10 1158–68) which are, to our knowledge, the most recent results of the above-mentioned flows.

Keywords: Second order modelling, direct numerical simulations, stratified turbulence


- 262-

Modeling of Unsteady Cavitating Flow

Hatem KANFOUDI, Hedi LAMLOUMI and Ridha ZGOLLI

LMHE-ENIT-TUNISIA.

[email protected]

Abstract

A 2D numerical model is proposed in this paper to simulate unsteady cavitating flows aroud hydrofoil NACA66mod. The objective of this study is to define a numerical procedure to modeling the unsteady cavitating flow. The Reynolds-averaged Navier-Stokes equations are solved for the mixture of liquid and vapor, which is considered as a single fluid with variable density. This variable is expressed as function of the vapor volume fraction. The closure of this variable is provided by the transport equation with a source term TEM. The processes of evaporation and condensation are governed by changes in pressure within the flow. The source terms is implanted in the CFD code ANSYS CFX v12. The influence of numerical and the physical parameters are presented in details. The numerical simulations are in agreed with the experimental data for steady and unsteady flow around the hydrofoil.

Keywords: turbulence model, transport equation, vapor pocket, growth and collapse.


- 264-

Numerical instabilities in a confined jet

with double diffusion

Soumaya Dhib1 , Mouhamed Ali Knani2 , Henri Claude Boisson3

1,2Laboratory units Fluides Département Mechanics Laboratory of Physics,

Faculty of Sciences of Tunis, University Tunis El Manar - Tunis Campus

Universitaire BP No. 94 Rumman 1068, Tunisia. 3Laboratory, University of Toulouse units, UPS, INP, Institute of Fluid

Mechanics, Avenue Camille Soula, 31400 Toulouse, France.

[email protected]

Abstract

Confined jets have been extensively studied because of their practical importance in the design of jet pumps and ejectors. In this work, we address the coupling between the transfer of momentum, heat transfer and mass transfer by diffusion. A numerical simulation is performed for the configuration of two-dimensional confined jet. This is to characterize the instabilities present in the flow at low Reynolds number between 100 and 1000. The mechanism of instability in the jet is confined evidenced by a sinusoidal perturbation procedure of flow to control and determine the characteristic frequencies of the instability.

Keywords: Instabilities, Diffusion, velocity component


- 265-

confined jet with double diffusion

CHATTI Monia, BELLAGI Ahmed

U. R. Thermique & Thermodynamique des Procédés Industriels, Ecole National

d’ingénieurs de Monastir, E.N.I.M, Av. Ibn Jazzar, 5060 Monastir, Tunisie.

[email protected]

Abstract

In this work, we address the coupling between the transfer of momentum, heat transfer and mass transfer by diffusion. A numerical simulation is performed for the configuration of two-dimensional confined jet. This is to characterize the instabilities present in the flow at low Reynolds number between 100 and 1000. The mechanism of instability in the jet is confined evidenced by a sinusoidal perturbation procedure of flow to control and determine the characteristic frequencies of the instability.

Keywords: Dimensionnement, Echangeurs thermiques HTFS , machine frigorifique,


- 267-

Crossover from weak to strong localization in quasi-

two-dimensional systems with diagonal disorder

Mokhtar DJELLOUL, Nouredine ZEKRI

Université des Sciences et de la Technologie d’ORAN - Mohamed Boudiaf.

LEPM, B.P. 1505 ORAN 31000-Algeria.

[email protected]

Abstract

We study numerically, but using a tight binding model, the Anderson metal-insulator transition (MIT) in the crossover from 1d to 2d systems. We determine the Lyapunov exponents, by using the transfer matrix method, in order to examine the diagonal disorder and the scaling effects on the nature of electronic states of the disordered systems.

Keywords: Disordered system, diagonal disorder, Lyapunov exponents.


- 268-

Performance Investigation of an Activated Carbon-

CO2 based Adsorption Cooling Cycle

Skander JRIBI1, Mohamed Salah ABID

1, Bidyut Baran SAHA

2,3

and Shigeru KOYAMA4

1Laboratory of Electro-Mechanical Systems, The Engineers National School of

Sfax, University of Sfax, Tunisia. 2Mechanical Engineering Department, Kyushu University, Japan.

3International Institute for Carbon-Neutral Energy Research

(WPI-I2CNER), Kyushu U

[email protected]

Abstract

In this study, a transient mathematical model of a 4-bed adsorption chiller using Maxsorb III as the adsorbent and CO2 as the refrigerant has been analyzed. The performances of the cyclic-steady-state system are presented for different heating and cooling water inlet temperatures. It is found that, with 80 kg of Maxsorb III, the CO2 based adsorption chiller produces 1.8 kW of cooling power at driving heat source temperature of 85°C along with a cooling temperature of 30ºC. The present thermal compression air-conditioning system could be driven with solar energy or waste heat from internal combustion engines and therefore is suitable for both residential and mobile air-conditioning applications.

Keywords: COP, Cooling capacity, Carbon dioxide, Maxsorb III, Transient model


- 270-

A New PV cell Model Based on Multi Model

Approach

Aicha ABID, Amel ADOUNI, Mouna BEN HAMED, Lassaad SBITA

Gabes University Research unit of Photovoltaic, Wind and Geothermal Systems

(PWGS), Tunisia.

[email protected]

Abstract

This paper presents a new model of the photovoltaic cell. First the classical mathematical model and the characteristics (the I-V and the P-V curve) are proposed. It shows the highly non linearity of the PV cell. The new model is based on the multi model approach. It is linear and easy to determine the maximum power point and the characteristics. It allows more flexibility in the system design. It tested with MATLAB program. Therefore, in this paper, a robust PV cell model is presented. The robustness is guaranteed using multimodel approach. This approach consists of four steps which are clusters estimation, structure identification, parametric identification and local models combination. The collected data on PV cell, inputs /output, are firstly, clustered into several groups through a Chui‟s clustering algorithm. Then, the structure identification is achieved on each group using the instrumental ratio (RDI) method. Parameters of each sub model are identified using recursive least square (RLS) method. Finally, obtained sub models are combined using the validity concept.

Keywords: model, PV cell, multi model approach, photovoltaic generator, Chui’s

clustering algorithm


- 271-

Two Scenarios in MicroGrid to solve Management

problem for Residential Application Using Genetic

Algorithms

Faisal A. MOHAMED, Aiman NOUH

Department of Electrical Engineering.Omar Al-Mukhtar University

P.O. Box 919, El-Bieda, Libya.

[email protected]

Abstract

This paper proposes a generalized formulation to determine the optimal operating strategy and cost optimization scheme for a MicroGrid (MG) for residential application. Genetic Algorithm is applied to the environmental/ecomomic problem of the MG. The proposed considered is a nonlinear constrained optimization problem. The proposed cost function takes into consideration the costs of the emissions, NOx, SO2, and CO2, start up costs, as well as the operation and maintenance costs. The MG considered in this paper consists of a wind turbine, a micro turbine , a diesel generator, a photovoltaic array, a fuel cell, and a battery storage. The Genetic Algorithms are aimed at minimizing the cost function of the system while constraining it to meet the costumer demand and safety of the system. We also add a daily income and outgo from sale or purchased power. Two typical scenarios of MG operation are investigated.The results demonstrate the efficiency of the proposed approach to satisfy the load and to reduce the cost and the emissions.

Keywords: microgrid, Genetic Algorithms, Optimization,online management, economic

power dispatch.


- 272-

Numerical Study of a Desiccant Cooling Installation

ZOUAOUI Ahlem1, ZILI-GHEDIRA Leila

2 and BEN NASRALLAH Sassi

3

1 National Engineering School of Monastir.



[email protected]

Abstract

The study and the development of the cooling system is one of the most interesting scientific research subjects. This technique is based on the water vaporization latent heat in order to produce a fresh cold air. Being heat driven, Desiccant cooling can be coupled to solar collectors to produce a cooling system with low environmental impact. The present work deals with heat and mass transfers during cooling in a desiccant cooling installation composed of a reactor filled with desiccant material, a heat exchanger and a humidifier. The ventilated air is cooled through this installation to reduce its temperature and adjust its humidity.The reliability and efficiency of the numerical tool established was tested and validated. The aim is to study and evaluate the phenomenon of sorption taking place in the reactor. The temporal evolution of temperature and relative humidity of air at the exit of each element of the desiccant cooling installation are plotted and analyzed.

Keywords: Desiccation, adsorption, desorption, heat exchanger, humidification


- 273-

Modeling and Supervision of Energetic Process :

a Double Effect Evaporator

Samia BEN ALI1, Faten BOUGHARRIOU

2, Mohamed AOUN

2

1Laboratory of Engineering Processes and Industrial Systems. 2Recherch Unit of modeling Analysis and Control Systems. 1,2

National Engineering School of Gabes, Gabes, Tunisia.

[email protected]

Abstract

This paper presents economic energetic process which is the double e ect evaporator. it re-duces energy consumption follow multiple e ect oration where only the energy used for the rst e ect is of external origin and each of the other e ects using the steam produced in the previous one. The principle physical phenomena encountered in this system is the heat transfer during distillation or concentration process. this work focused in modeling of the double e ect evaporator using a bond graph approach. This modeling approach allows description of interdisciplinary systems involving di erent physical phenomena such as energetic, thermodynamic, hydraulic and thermic. in this study a dynamical models and analytical redundancy relations (ARR) for the di erent parts of the double e ect evaporator are established. Experimental data are presented and confronted to the simulation results.

Keywords: process, energy, double e ect evaporator, modeling, simulation, supervision.


- 274-

Dumping Effects of forcEd Sloshing Motion with

Submerged Vertical Baffles

Zeineb SAOUDI, Zouhaier HAFSIA, Khlifa MAALEL

Ecole Nationale d’Ingénieurs de Tunis. Laboratoire de Modélisation en

Hydraulique et Environnement. B.P. 37.

Le Belvédère, 1002 Tunis, Tunisia.

[email protected]

Abstract

In this paper, we study a force sloshing in a partially filled bi-dimensional 2-D oscillating rectangular tank. The hydrodynamic model of forced sloshing motion with obstacle solves the Reynolds averages Navier-Stokes equation (RANS) and the standard k–epsilon turbulence model. The Volume of Fluid method (VOF) has been adopted for capturing the free surface flow where CFX code is adopted to solve the transport equation describing the free surface flow field. The compared computed results and analytical solution without baffles and at resonance case show a good agreement When the frequency of the external excitation close to the 0.98 natural frequency of the sloshing motion, the free surface displacement become more larger than the case of excitation frequency close 1.1 sloshing natural frequency. The damping effects on the sloshing response of the internal mounted vertical baffles and vertical baffle at free surface are investigated and discussed. The simulated results with vertical baffles located at the middle of the tank show that under harmonic excitation and at resonance case, the displacement amplitude decreases with increasing of the sloshing frequency. When the vertical baffle height equal hb =0.75h of the still water depth, the comparison between numerical simulation and numerical results of Lin (2009) agree very well. To eliminate the beating phenomenon, a vertical baffle at free surface is proposed. Numerical simulation show that the displacement amplitude decrease and the beating phenomenon eliminated. This reduction is attributed to the evolution of vortex shedding near the tip baffle.

Keywords: beating motion, forced sloshing, free surface, non-linear, resonance, vertical

baffles, vortex shedding.


- 275-

Experimental and Numerical Study of Flow Issued

from a Chimney Around a Cylindrical Obstacle

S. HABLI1, N. MAHJOUB SAID

2, G. LE PALEC

3 and Ph. BOURNOT

3

1EMIR, IPEIM, Université de Monastir, Tunisie.

2LGM, IPEIM, Université de Monastir, Tunisie.

3IUSTI, UMR 6595, Technopôle de Château-Gombert,

Marseille, France.

[email protected]

Abstract

The flow and dispersion of atmospheric pollutants issued from a chimney into a crossflow in the near-wake region of buildings is a complex problem and useful in identifying the behavior of effluents plumes released in their vicinity. In this paper, velocity measurements using PIV are conducted in order to describe the structure of the flow issued from a straight chimney in presence of a cylindrical obstacle under different velocity ratios (the jet to cross-flow velocity ratio). Then we propose a three-dimensional numerical model based on the RSM second order closure turbulent model and on a non-uniform grid to analyze the different vortex structures resulting from the interaction of the flow issued from the chimney with the cylindrical obstacle.

Keywords: experimental study, numerical study, chimney, cylindrical obstacle, crossflow


- 276-

Numerical and Experimental study of a Jet in

Crossflow

R. BEN KALIFA1, S. HABLI

2, N. MAHJOUB SAID

3, G. LE PALEC

4

and Ph. BOURNOT4

1LGM, ENIM, Université de Monastir, Tunisie.

2EMIR, IPEIM, Université de Monastir, Tunisie.

3LGM, IPEIM, Université de Monastir, Tunisie.

4IUSTI, UMR 6595, Technopôle de Château-Gombert,

Marseille, France.

[email protected]

Abstract

This paper deals with a flow generated by the interaction between a circular jet and a crossflow. A better understanding of the process of the interaction of this type of flow was performed experimentally using a Particle Image Velocimetry (PIV) technique. A numerical simulation was also presented of the same configuration, using the Fluent software solving the Navier-Stokes equations with the finite volume method. We have also investigated the effect of velocity ratio on the flow structure.

Keywords: Jet, crossflow, turbulence model, Three-dimensional


- 277-

Simulation and control of flow injection in the

microsystems

DENNAI Brahim1, (a)

, KHELFAOUI Rachid1, LAAREDJ Setti

1,

CHEKIFI Toufik1

1 ENERGARID laboratory, BECHAR University, ALGIERS

(a) [email protected]

Abstract

This work is oriented mainly on the control and the simulation of the flow injection in the microsystems. As being based on the principle of the fluidics oscillators, staleness as well as the Tesla diode, we are going to elaborate what follows:

Keywords: Simulation, flow, injection, microsystems, fluidics oscillators, Tesla diode.


- 282-

Performance evaluation of solar box oven with

automatic tracking system

DR. Isa GARBA and Daniel MADU BZIGU

Department of mechanical engineering, bayero university, kano.

[email protected]

Abstract

- To search for an optimal geometry as for the closing and to the opening of the fluidinjection.

- To eliminate or rather to minimize the return of fluid to the level of the injection

systems. - To control the order of opening and closing of the injection

Keywords: Tracking system, collector, reflector

december 20-22, 2012 sousse tunisia2012.irec-conference.com/files/final_proceedings.pdf · pr....

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