training report on kalisindh super thermal power project, jhalawar

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TRAINING REPORT

KaTPP

(JHALAWAR)RRVUNL

SUBMITTED BYRADHEY SHYAM MEENA

B.TECH, ELECTRICAL ENGINEERINGGOVT ENGINEERING COLLEGE JHALAWAR, RAJASTHAN 326023

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APRACTICAL TRAINING REPORT

ON

2 X 600 MW KALISINDH THERMAL POWERPROJECT, JHALAWAR

(RRVUNL)

SUBMITTEDIN PARTIAL FULFILMENT

FOR THE DEGREEBACHELOR OF TECHNOLOGY(B.TECH)

INELECTRICAL ENGINEERING

DEPT. OF ELECTRICAL ENGINEERINGGOVT ENGINEERING COLLEGE JHALAWAR

RAJASTHAN TECHNICAL UNIVERSITY KOTA

SUBMITTED BYRADHEY SHYAMMEENAB.TECH, FINAL YEAR

ENROLLMENT NO. 9E1EJEEM20P037MAY-JUNE 2012

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PREFACE OF TRAINING

In today’s world, electricity has an important role. today, rely on electricity for the

fulfillment of even his basic needs comfortable living. Electricity contributes the largest

share to a country’s economic growth. It is the most powerful resource and has brought

industrial revolution world wide. It has resulted in social changes too and raised the

standard of living. In India, several organizations like NHPC, NTPC, POWER GRID,

and other state electricity boards etc. are engaged in electricity generation. RRVUNL is

one of the largest among these with an honourable Contribution.

The rise in civilization is closely related to improvements in transportation and

requirement of energy that is not readily available in large quantities but is also readily

transportable. There are several sourse of energy in world in which thermal power plant

is also a sourse of energy.It give electrical energy. A very peculiar fact about electrical

energy is that neither it is directly available in nature nor it is directly used finally in this

form, yet it is so widely produced and is the most popular high grade energy.

The purpose behind training is to understand the difficult concepts in a better

way with gain of knowledge. Report starts with a brief introduction of KaTPP.

While writing the report and while i was on my training i was wondering that

Science and technology are as ever expanding field and the engineers working hard day

and night and make the life a gift for us.

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ACKNOWLEDGEMENT

“Every good work requires the guidance of some experts.”Many lives & destinies are destroyed due to the lack of proper guidance, directions &opportunities. It is in this respect I feel that I am in much better condition today due tocontinuous process of motivation & focus provided by my parents & teachers in general.The process of completion of this project was a tedious job & requires care & support atall stages. I would like to highlight the role played by individuals towards this.

I oblige to acknowledge my heartiest gratitude to all honourable people whohelped me during my summer training at KALISINDH THERMAL POWERPROJECT-JHALAWAR,(RRVUNL)RAJASTHAN.

I want to express my thanks to Mr. S.S. Meena Chief Engineer KaTPP,Mr.S.N.Reja Project Incharge TCE Ltd. and Mr. Sunil Gangwal , G.M.(EE) BGREnergy System for granting me the permission for doing my summer training at thisproject And to give their valuable time and kind co-operation.

I would like to thank Mr. S.N.Soni (X-En Elect-1), Mr. Raju (TataGroup),& Mr. B.B. Malav (A.En Elect-2) for providing the necessary guidance.

I would like to Thank Mr. Lekhraj Meena (J.En,Elct-2, RRVUNL), Mr.Deepak Khndelwal (J.En,Elect-1, RRVUNL), Mr. Mithun Patidar (J.En,Elect-1,RRVUNL), & Mr.Raman Sir (J.En,TG Operation,BGR ENERGY SYSTEM) forproviding me the knowledge about the work and giving their valuable guidance duringmy training period.

I Would Co-Heartedly Thank And Use This Opportunity To ExpressGratitude And Debtness To Mr.M.M.Sharma(Principal,Gecj), Mr. Neeraj GargH.O.D. Electrical Engineering, Mr.Shrad Mahesvri & Mr. Nitin Arya, PlacementOfficer, T & P Cell, Govt Engineering College Jhalawar For Allowing Me To DoMy Training At This Place.

I am also thanks alot to other staff members of RRVUNL, BGR & TCE fortheir further co-operation to gain the better knowledge about the world class powerplant project in distt –Jhalawar, Rajasthan.

RADHEY SHYAMMEENAB.TECH 4th YEAR

ELECTRICAL ENGINEERING

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COLLEGE-CERTIFICATE

This is to certify that Mr. RADHEY SHYAM MEENA , B.Tech.(Electrical

Engineering) 4th year VII. semester has submitted His Training report entitled

“..2X600MW KALISINDH THERMAL POWER PROJECT

JHALAWAR(RAJASTHAN) RRVUNL..” under my/our guidance.Report submitted

by him is based on practical knowledge and as good as in my experience.

Mr.NEERAJ GARGASST.PROF. & H.O.D. ELECTRICAL ENGINEERING

Designation of Seminar Guide

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CONTENT

CHAPTER-01 INTRODUCATION1.1 INTRODUCATION OVERVIEW OF KATPP………………………...011.2 ENERGY GENERATED IN KATPP…………………………………...051.3 PLANT OVERVIEW……………………………………………………..051.4 PRINCIPLE OF OPERATION………………………………………….071.5 THERMAL PLANT OPERATION PROCEDURE……………………10

CHAPTER-02 COAL HANDLING SYSTEM2.1 COAL HANDLING PLANT……………………………………………...132.2 STAGE OF COAL HANDLING……………………………………….....16

CHAPTER-03 RAW WATER CYCLE & COOLING SYSTEM3.1 WATER TREATMENT PLANT……………………………………….…183.2 DM PLANT…………………………………………………………………233.3 COOLING TOWER………………………………………………………..243.4 H2 GENERATION PLANT…………………………………………….…28

CHAPTER-04 STG SYSTEM4.1 BOILER……………………………………………………………..……….294.2 TURBINE……………………………………………………………………344.3 GENERATOR………………………………………………………………374.4 DIESEL-GENERATOR SET……………………………………………...39

CHAPTER-05 TRANSFORMER5.1 TRANSFORMER………………………………………………………….40

5.1.1 SLD GENERATING TRANSFORMER5.1.2 SLD UNIT TRANSFORMER

CHAPTER-06 ESP & ASP CYCLE SYSTEM6.1 ELECTRO STATIC PRECIPITATOR…………………………………..476.2 ASH HANDLING PLANT………………………………………...………49

CHAPTER-07 SWITCHYARD ,C &I PROTECTION7.1 SWITCHYARD……………………………………………………………51a) SLD CAPCITIVE VOLTAGE TRANSFORMERb) SLD INTER CONNECTED TRANSFORMERc) SINGLE LINE DIAGRAM OF SWITCHYARDd) SLD 400KV LINE-03 DAHRA BAY-12

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e) SLD 400KV LINE-01 BATAWDA BAY-05f) SLD 400KV LINE-02 BATAWDA BAY-09g) SLD 400KV SPARE LINE BAY-01h) SLD 400KV TIE LINE BAY-02i) SLD 400KV ICT LINE BAY-03j) SLD 220KV LINE-01 JHALAWAR BAY-01k) SLD 220KV LINE-02 JHALAWAR BAY-03l) SLD 220KV ICT LINE BAY-02m) SLD 220KV BUS COUPLER BAY-05n) SLD 220KV TRANSFER COUPLER BAY-047.2 SWITCHGEAR……………………………………………………………777.3 PROTECTION……………………………………………………………..797.4 CONTROL ROOM………………………….………………………...……817.5 AUXILLARY SUPPLY………………….…………………………………82

CHAPTER-08 EFFICIENCY8.1 POWER PLANT EFFICIENCY CALCULATION…..………………….858.2CONCLUSION………………...…………………………………..………..87

CHAPTER-07REFERENCE/BIBLIOGRAPHY-……………………………………………………….…88

APPENDICES:--

APPENDIX-I- PLANT LOCTED IN RAJASTHANAPPENDIX-II- POWER DISTRIBUTION MAP OF RAJASTHANAPPENDIX-III-KaTPP PLAN MAPAPPENDIX-IV-KaTPP SWITCHYARD PLAN MAP

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LIST OF FIGURES

1. KaTPP PROJECT & PLANT OVERVIEW2

2. PLANT RUNNING VIEW7

3. RANKING CYCLE8

4. ENERGY CYCLE9

5. COAL CYCLE & COAL PROCESS 14-15

6. WATER TREATMENT PROCESS 21-22

7. COOLING TOWER24

8. FLOW OF WATER &KaTPP BOILER32

9. TURBINE & HP/ LP/ IP36

10. GENERATOR37

11. STEAM OVERVIEW39

12. GT/UT/UAT43

13. ASH HANDLING PLANT50

14. SWITCHYARD52

15. CIRCUIT BREAKER54

16. LIGHTING ARRESTER57

17. EARTHING ISOLATOR58

18. CURRENT TRANSFORMER59

19. CVT60

20. ICT64

21. CONTROL ROOM81

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LIST OF TABLE

1.PLANT REPORT 05

2. IMPORTANT DATE 06

3. BOILER MOTOR DATA SHEET 31

4. TURBINE DATA SHEET 35

5.GENERATOR DATA SHEET 38

6.DG SAT DATA SHEET 39

7.GENERATING TRANSFORMER DATA SHEET 41

8. UNIT TRANSFORMER DATA SHEET 44

9.PARAMETER FOR CIRCUIT BREAKER 55-56

10 ISOLATOR PARAMETER 57

11 LIGHTING ARRESTER SHEET 58

12 CURRENT TRANSFORMER 59

13 CAPACITOR VOLTAGE TRANSFORMER 60-61

14.INTER CONNECTED TRANSFORMER 63

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SINGLE LINE DIAGRAM

1. GENERATING TRANSFORMER 422. UNIT TRANSFORMER 453. CVT 624. ICT 655. 400KV LINE-03 DAHRA BAY-12 666. 400KV LINE-01 BATAWDA BAY-05 677. 400KV LINE-02 BTAWDA BAY-09 688. 400KV SPARE LINE BAY-01 699. 400KV TIE LINE BAY-02 7010. 400KV ICT LINE BAY-03 7111. 220KV LINE-01 JHALAWAR BAY-01 7212. 220KV LINE -02 JHALAWAR BAY -03 7313. 22KV ICT BAY-02 7414. 220KV BUS COUPLER BAY-05 7515. 220KV TRANSFER COUPLER BAY-04 76

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CHAPTER-01 INTRODUCATION

Everybody must be having a thought that a thermal power plant is a place where electricity isproduced. But do you know how it is produced? The chemical energy stored is converted to heatenergy which forms the input of power plant and electrical energy produced by the generator isthe output. Power is the single most important necessity for the common people and industrial

development of a nation. In a convectional power plant the energy is first converted to amechanical work and then is converted to electrical energy. Thus the energy conversions

involved are:

The first energy conversion takes in what is called a Boiler or Steam Generator, the second inwhat is called a Turbine and the last conversion takes place in the Generator.

A thermal power station is a power plant in which the prime mover is steam driven. Water is

heated, turns into steam and spins a steam turbine which drives an electrical generator after it

passes through the turbine, the steam is condensed in a condenser and recycled to where it

was heated; this is known as a rankine cycle.

Commercial electric utility power stations are usually constructed on a large scale and

designed for continuous operation. Electric power plants typically use three-

phase electrical generators to produce alternating current (ac) electric power at

a frequency of 50hz.

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1.1 INTRODUCATION

KaTPP

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FIG-1 .KATPP (1)PLANT PROJECT VIEW ,FIG-2 (2) PRESENT VIEW

KaTPP

BGR

RRVUNL

TCE

2x600 MW KALISINDH THERMAL POWERPROJECT-JHALAWAR

RRVUNLOWNER

TATA CONSULTINGENGINEERS LTD.MUMBAI

OWNER'SCONSULTANT

BGR ENERGY SYSTEM LTD.CHENNAI

EPCCONTRACTOR

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The site of Kalisindh Thermal Power Project is located in Nimoda, Undal, Motipura,

Singhania and Devri villages of Tehsil Jhalarapatan, Distt. Jhalawar. The proposed

capacity of coal based Thermal Power Project is 1200 MW. The project site is about

12 km from Jhalawar (Distt. Head quarter ) and NH-12 .It is 2km from state highway

No.19 and 8 km from proposed Ramganj Mandi - Bhopal broad gauge rail line.

The site selection committee of Central Electricity Authority has visited the

Nimodha and its adjoining villages of Jhalawar Distt. And site was found techno-

economical feasible for setting up of a Power Project. The Govt. of Raj. have included

that project in 11 th five year plan. The estimated revised cost of the project is

Rs.7723 Crores. M/s. TCE Banglore has been appointed as the technical consultant

for the project. The state irrigation department has alloted 1200 mcft water for the

project from proposed Kalisindh dam. The origin of the Kalisindh river is from northern

slop of Vindya Mountains . The river enters from MP to Rajasthan near village Binda.

After flowing 145 km in Rajasthan, the Kalisindh river merges in Chambal river near

Nanera village of Distt. Kota.Its catchment area is about 7944 sq.km in Jhalawar &

Kota Distt. The existing Dam is located at Bhawarasa village, primarily for P.H.E.D.

purpose is being uplifted for providing a storase of 1200mcft water for this power

project.

The GOR has alloted 842 bigha Government land and aquired 1388 bigha

private khatedari land for the thermal project .Phase-1 will be constructed on 1400

bigha land only.EPC contract has been awarded to M/s. BGR Energy System

Chennai on dt.09/07/08, through ICB route at cost Rs.4900 Crores. Ministry of coal,

Govt. of India has alloted ‘Paras east and Kanta basin ‘ coal blocks to RVUN in

Chhatisgarh state. The RVUN has formed new company under joined venture with

M/s. Adani Enterprises for mining of coal blocks and new company started the work.

Annual coal requirement for the project is 56 LacsTPA. GOR also decided to setup

two new units of 2x660 MW in next few years.

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1.1.2 ENERGY GENERATED IN KaTPP

Total generation Capacity= (2 x 600)= 1200 MWTotal generated Electricity (in one hour)

= 1200 MW x 1=12.00 Lakh units

Total generated Electricity (in 24hours)= 12.00 x 24= 288.0 Lakhs units

Amount of Coal required (per day) in KaTPP is= 0.5 x 288.0 x 100000 Kg.=144million kg

1.1.3 PLANT OVERVIEW

Project Kalisindh Super Thermal Power Project Jhalawar

Capacity 1200 MW(2x600 MW)

Project SiteVillage-Undel, Motipura, Nimoda, Singhania & Deveri of

Tehsil Jhalarapatan, Distt. Jhalawar

Project Location

The project site is about 12 km from NH-12, 2km from state

highway and 8 km from proposed Ramganj Mandi - Bhopal

broad gauge rail line.

Land Area 2230 Bigha/564 Hq. (1400 bigha/350 Hq. in I stage)

Water source and

quantityDam on Kalisindh river. 3400 CuM/ Hrs.

Fuel SourceMain Fuel- Coal from captive coal blocks (Paras east and

kanta Basin in Chhatisgarh state) Secondary Fuel- FO/HSD.

Quantity of Fuel (at

80% PLF)Coal-56 Lacs TPA FO/HSD-13000-14000 KL/A

ElectroStatic

Precipitator99.98 % Capacity

Stack Height 275 Mtr.

Estimated revised

CostRs.7723 Crores

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1.1.4 IMPORTANTMILESTONE FOR UNIT-1/2 & COMMON SYSTEM

SI

NO.Activity

Scheduled

Date U#1

Actual

Date

Scheduled

Date U#2

Actual

Date

01 Start of Boiler Foundation 28.04.2009 24.01.200911.07.2009 23.03.2009

02 Start of Boiler Erection 07.12.2009 23.10.200905.03.2010 26.03.2010

03 Boiler Drum Lifting 06.05.2010 19.05.201003.07.2010 14.08.2010

04 Readiness of startup power 12.02.2011 28.04.2011

05Completion of commissioning of

DM Plant25.12.2010 25.12.2010

06 Boiler Hydro Test 05.01.2011 08.04.201130.03.2011

07Readiness of Chimney (1st / 2nd

Flue only)02.06.2011 30.04.201127.04.2011

08 Readiness of UCB 24.09.2010 09.12.2010

09 Boiler Lightup 07.06.2011 05.09.2011

10 Start of Condenser Erection 23.06.2010 27.11.201015.11.2010

11 Start of TG Erection 30.08.2010 20.12.201008.11.2010

12Turbine Generator & Auxiliaries

Box Up24.06.2011 13.09.2011

13 Readiness of Cooling Tower 02.08.2011 02.11.2011

14 Turbine on Barring Gear 16.08.2011 02.11.2011

15 Completion of Coal handling 30.08.2011 30.08.2011

16 Completion of Ash handling 13.06.2011 19.08.2011

17 Readiness of 400 KV Switch Yard 11.12.2010 07.02.2011

18Rolling of Turbine &

Synchronisation05.09.2011 07.12.2011

19 Completion of Trial Operation 02.01.2012 02.04.2012

20 Provisional Handing Over 2013 2013

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1.2 PRINCIPLE OF OPERATION

For each process in a vapour power cycle, it is possible to assume a hypothetical or idealprocess which represents the basis intended operation and do not produce any extraneouseffect like heat loss.1. For steam boiler, this would be a reversible constant pressure heating process of waterto form steam.2. For turbine, the ideal process would be a reversible adiabatic expansion of steam.3. For condenser, it would be a reversible a constant pressure heat rejection as the steamcondenser till it becomes saturated liquid.4. For pump, the ideal process would be the reversible adiabatic compression of liquidending at the initial pressure. When all the above four cycles are combined, the cycleachieved is called RANKINE CYCLE. Hence the working of a thermal power plant isbased upon Rankine cycle with some modification.

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FIG-3 THERMAL PLANT PROCESS DIAGRAM

A PULVERIZED COAL FUELED POWER PLANT

A typical pulverized coal fueled power plant is based on Rankine Thermodynamic cycle.

“A Rankine cycle is a vapour cycle Furnace that relies on the isentropic expansion of

high pressure gas to produce work”. Let us see a superheat Rankine cycle:

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FIG-4 RANKING CYCLE

Where, Wt – mechanical power produced by turbine

This facility first produces steam in a boiler (steam generator). This steam is used to

rotate turbine which is connected to a shaft of generator. Hence electricity is produced

here. The used steam is then condensed in a condenser, and the condensed liquid is used

again in the steam generator. This is a simple phenomenon, understood by everybody.

For all this we need a fuel. As the name suggest here coal is used as fuel. Coal is one of

the cheapest and most preferred fossil fuel used as a key to most of the power plants.

Usually delivered by train from Mines to the Coal Handing Plant (CHP). The CHP

unloads this it become more economical to unload the coal. Then the coal stacked,

reclaimed, crushed, and conveyed it to the storage silos near the steam generator. Then it

is fed through the Feeder to the Pulverizer. Feeder is mainly used to weight the amount of

coal going to the Pulverizer per hour. From the Feeder the coal is fed to the Pulverizer

which powders it and then it is carried to the steam generator using pressurized air.

Within the steam generator the coal is atomized and burned and the heat energy produced

is used for producing steam. Here two types of steam namely superheated & reheated

steam are produced in a cycle. The steam turbine generator converts the thermal energy

of superheated and reheated steam to electrical energy. The first energy conversion is

carried in Boiler or steam generator; the second is carried out in Turbine and the last one

carried out in the Generator.

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FIG-5 ENERGY CYCLE

Initially the superheated steam is fed to High Pressure (HP) turbine. It has a temperature

of 540° C (approx.) and a pressure of about 140 Kg/cm2. Then the exhausted steam from

it is taken to the reheater so that it can be reheated and fed back to Intermediate Pressure

(IP) turbine. Here the temperature is maintained the same as that of superheated steam

but pressure is reduced to 35 Kg/cm2. Then the exhausted steam is directly fed to Low

Pressure (LP) turbine having the reduced temperature and pressure of about 1 Kg/cm2.

Then the exhausted steam from the LP section is condensed in the condenser. The

condensed liquid is moved from condenser by Condensate Pumps through Low Pressure

Regenerative Feedwater heaters to a Deaerator. Boiler Feed Pumps (BFPs) moves the

deaerated liquid through HP heaters to the steam generators. Extraction steam is supplied

to the LP & HP regenerative heaters to improve cycle efficiency. Then comes to the

system of fans which keeps the system working by providing the valuable air where

required. There are three pairs of fans, namely, Forced Draft (FD) fan, Induced Draft (ID)

fan, Primary Air (PA) fan. FD fans supplies combustion air to the steam generator and

PA fans transports the coal into the steam generator. ID fans remove the flue gases from

the steam generator and exhaust it through chimney. Cooling water for the condenser is

supplied by the circulating water system, which takes the heat removed from the

condenser and rejects it to the cooling towers or other heat sink. This all working is

controlled from a single place called control room. It enables the operator to direct the

plant operation for reliable and efficient production of electrical energy. This is achieved

by the control system installed by the C & I group. These are DAS (Data Acquisition

System), ACS (Analog Control System), FSSS (Furnace Safeguard Supervisory System),

and other relays governing numerous activities. Last but not the least is the switching and

transmission methods used here. The generated power cannot be transmitted as such. It is

stepped up to 132 KVA or 400 KVA then passed through a series of three switches an

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isolator, a circuit breaker and an isolator. Three phase system is used for the power

transmission. Each generator has its own switchyard and transmission arrangement.

1.3 THERMAL PLANT OPERATION PROCEDURE

The basic understanding of the modern thermal power station in terms of major systems

involved can be done under three basic heads viz. generating steam from coal, conversion

of thermal energy to mechanical power and generation & load dispatch of electric

power.

1. COAL TO STEAM:

The coal is burnt at the rate up to 200 tonnes per hour.

From coal stores, the fuel is carried on conveyor belts to bunkers through coal tipper.

It then falls in to coal pulverizing mill, where it is grounded into powder as fine as

flour.

Air is drawn in to the boiler house by drought fan and passed through Preheaters.

Some air is passed directly to bunker and rest, through primary air fan, to pulverizing

mill where it is mixed with powdered coal.

The mixture is then carried to bunker of furnace where it mixes with rest of the air and

burns to great heat.

This heats circulating water and produces steam, which passes to steam drum at very

high pressure.

The steam is then heated further in the Superheater and fed to high pressure cylinder

of steam turbine.

The steam is then passed to other cylinders of turbine through reheater.

The spent steam is sent to condenser, where it turns back to water called condensate.

Condensate is sent to lower part of steam drum through feed heater and economizer.

The flue gases leaving boiler are used for heating purpose in feed heater, economizer,

and air Preheater.

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The flue gases are then passed to electro-static precipitator and then, through draught

fan, to chimney.

2.STEAM TO MECHANICAL POWER:

Steam first enters the high pressure cylinder of turbine where it passes over a ring of

stationary/fixed blades which acts as nozzle and directs steam onto a ring of moving

blades.

Steam passes to the other cylinders through reheater and the process is repeated again

and again.

This rotates the turbine shaft up to 3000 rpm.

At each stage, steam expands, pressure decreases and velocity increases.

3.MECHANICAL TO ELECTRICAL POWER:

The shaft is connected to an alternator’s armature.

Thus the armature is rotated and electric current is produced in the stator’s windings.

The generated electricity is of order 25,000 volts.

4.SWITCHING AND TRANSMISSION:

Electricity generated can not be transmitted as such.

It is fed to one side of generator’s transformer and stepped up to 132000, 220000, or

400000 volts.

It is then passed to a series of three switches an isolator, a circuit-breaker, and another

isolator.

From circuit-breaker, current is taken to bus bars and then to another circuit-breaker

with it’s associated isolator before being fed to the main Grid.

Each generator has its own switching and transmission arrangement.

Three-phase system is used for power transmission.

5. CONTROL AND INSTRUMENTATION

Control and Instrumentation (C & I) systems are provided to enable the power station to

be operated in a safe and efficient manner while responding to the demands of the

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national grid system. These demands have to be met without violating the safety or

operational constraints of the plants. For example, metallurgical limitations are important

as they set limits on the maximum permissible boiler metal temperature and the chemical

constituents of the Feed water. The control and Instrumentation system provides the

means of the manual and automatic control of plant operating conditions to:

Maintain an adequate margin from the safety and operational constraints.

Monitor these margins and the plant conditions, and provide immediate indications

and permanent records.

Draw the attention of the operator by an alarm system to any unacceptable reduction

in the margins.

Shut down the plant if the operating constraints are violated.

TYPES OF INSTRUMENTSThe different types of instruments normally used are given below:

INDICATORS – These are of two categories, namely local and remote. Local indicators

are self contained and self operative and are mounted on the site. The Remote indicators

are used for telemeter purposes and mounted in the centralized control room or control

panel. The indicators are sometimes provided with signaling contacts where ever required.

The

Remote indicators depend on electricity, electronics, pneumatic or hydraulic system for

their operation and accordingly they are named. The indicator can be classified as

analogue or digital on the basis of final display of the reading.

·RECORDERS – These are necessary wherever the operating history is required for

analyzing the trends and for any future case studies or efficiency purposes. Recorders can

be of single point measuring a single parameter or multipoint measuring a number of

parameters by single instruments. Multipoint recorders are again categorized as

multipoint continuous or multipoint dot recorders. The multipoint dot recorders select the

point one after the other in a sequence where as the continuous recorders measure

simultaneously all the poinS.

CHAPTER-02 COAL HANDLING SYSTEM

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2.1 COAL HANDLING PLANT

INTRODUCTION:-Every thermal power plant is based on steam produced on the expanse of

heat energy produced on combustion of fuel. Fuels usednare coal and fuel oil. Coal is

more important as oil is occasionally used. Coal is categorised as follows depending upon

fixed carbon, volatile matter and moisture content:

Anthracite having 86% fixed carbon

Bituminous having 46 to 86% fixed carbon

Lignite having 30% fixed carbon and

Peat having 5 to 10% fixed carbon

Coal from mines is transported to CHP in railway wagons. It is unloaded in

track hoppers. Each project requires transportation of large quantity of coal mines to the

power station site. Each project is established near coal mine which meets the coal

requirements for the span of its entire operational life. For the purpose each plant has

Merry Go-Round (MGR) rail transportation system. The loading operation of the coal

rake takes place while it is moving under the silo at a present speed of 0.8 Km/hr. the

loading time for each wagon is one minute. For unloading of coal from the wagons an

underground track hopper is provided at the power station end.

The term coal handling plant means to store and to handle the coal which is

transported by the train and convey to the bunkers with the help of belt conveyers.

Through the bunkers coal is transferred to the coal mill and drifted to the furnace. The

coal handling plant includes wagon tippler, conveyer belt, crusher house, stacker &

reclaimer, bunkers & coal mill.

CHP then normally follows three coal paths:

1. PATH A – FROM TRACK HOPPERS TO BUNKERS.

2. PATH B – FROM TRACK HOPPERS TO STOCKYARD.

3. PATH C – FROM STOCKYARD TO BUNKERS.

PATH-A

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PATH-B

PATH-C

FIG-06 COAL CYCLE PATH

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FIG-07 WAGON TIPLAR, FIG-08 CRUSHUR HOUSE , PROCESS VIEW

Coal Supply in KaTPP:-Ministry of coal, Govt. of India has alloted ‘Paras east and

Kanta basin ‘ coal blocks to RVUN in Chhatisgarh state. The RVUN has formed new

company under joined venture with M/s. Adani Enterprises for mining of coal blocks

and new company started the work. Annual coal requirement for the project is 56 Lacs

MILLSThese are basically coal pulverizing mills. Thermal power stations use pulverized coal

firing system. In this the coal is reduced to fineness such that 70 to 80% passes through a

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200 mesh sieve. This fine powdered coal is called pulverized coal and is carried forward

to the burner by air through pipes.

Advantage of pulverized coal firing system:–

1. Efficient utilization of low grade and cheap coal.

2. Flexibility in firing.

3. Ability to meet fluctuating load.

4. Better reaction to automatic control.

5. High efficiency of boiler.

6. Easy complete combustion.

The only disadvantage being its high initial cost.

2. 1 STAGES OF COAL HANDLING PLANT:- WAGON TIPPLER:-

The term Wagon Tippler contains two words WAGON & TIPPLER .Wagon

means the compartment of train which is just like a container which is used to carry the

coal from mines to generating stations & the word Tippler means a machine, which is

used to unload the wagon into the hopper. Hopper is just like a vessel which is made of

concrete & it is covered with a thick iron net on its top. Here big size coal pieces are

hammered by the labors to dispose it into the hopper.

Coal is fed into mill through Gravimetric feeder. When the A.C. supply is

switched on the bowl rotate and due to centrifugal force, the coal moves in the outward

direction. As the coal come between grinder and bowl, it gets pulverized. The unwanted

material is removed through scrapers. The pulverized coal is then carried to burners by

primary air through outlet openings. The heavier particles, as they rise, collide with

classifiers and fall back in mill for further grind. Sealing air is provided through seal air

fan to avoid deposition of coal dust in bearings and spring mechanism.

CONVEY OF COAL TO CRUSHER HOUSE:-

After unloaded the coal wagon into the concrete hopper, the supply of coal

is control by Apron Feeder and Scrapper. Apron feeder is made of iron .After passing

through the scrapper conveyor the coal is fed into the Roll Crusher where the crushing

29

of coal takes place. In the roll crusher there are two shafts on which metal hammer are

mounted, these two rollers rotates in opposite direction to each other. When the coal

comes in between these two rollers it gets crushed into small pieces and then convey to

the separator through belt conveyor. In Pent house there is a belt weightier which is used

to weight the belt which carry the coal and feed into the separator with the help of Flap

Gate .

PRIMARY CRUSHER HOUSE:-

Coal crusher house is a part of coal handling plant where the coal is

crushed with the help of a crusher machines .In crusher machine there is pair of two

shafts on which hammer are fixed. Both shafts rotates in opposite direction due to which

when coal comes between the two shafts crushed into the small pieces and conveyed to

the bunkers or open storage (stacker) according to the requirement through the belt

conveyor.

STACKER & RECLAIMER:-

Stacker is a place where the open storage of a coal takes place. Reclaimer

means the unloading of coal from the stacker.

COAL MILL:-

In coal mill, coal is pulverized or crushed properly into the powdered

form. Hot air is mixed with powdered coal to remove the moisture from the coal, which

increases the efficiency of plant. Pulverization is done to increase the surface area of

coal. From coal mill coal is drift to the furnace with the help of air. There are four main

equipment of coal mill, which are as follows:-

Bunkers:-These are basically used to store crushed coil which comes from crusher

house.

Feeders:-These are used to control the supply of crushed coal to the mill depending

upon load condition.

Feeder pipe:- Feeder pipe are used to convey the crushed coal to the Tube mill or Bowl

mill.

Tube mill:-Tube mill is used to pulverize the crushed coal. In the tube

30

CHAPTER-03,RAW-WATER CYCLE & COOLING SYSTEM

3.1 WATER TREATMENT PLANT

The principal problem in high pressure boiler is to control corrosion and

steam quality. Internal corrosion cost power station crores of rupees.

The water available can not be used in boilers as such. The objective of water

treatment plant is to produce the boiler feed water so that there shall be

· No scale formation

· No corrosion

· No priming or forming problems

The treated water is called ‘Dematerialized Water’. The treatment process can be divided

in two sections:

1. Pre-treatment section

2. Demineralisation section

PRE-TREATMENT SECTION

Pre-treatment plant removes suspended solids like clay, salt, plants,

micro-organisms etc form raw water to give clarified water. Suspended solids can be

separable or non-separable. Separable solids are heavier & large and can easily be

removed by an aerator. Non-separable solids have finer size and take long to settle down.

Hence they are required to be flocculated. In this, water is first dozed with lime and alum.

This forces finer particles to coagulate increasing their weight and size. Non-separable

solids can now be separated in clariflocculator. The clarified water is then stored in

clarified water storage tanks.

DEMINERALISATION SECTION

The clarified water now goes to FCA (activated carbon filter) where it

de-chlorinated. Water then passes through cation exchanger where weak and strong

acidic cations are removed on adding resin.

RH + Na RNa + H2SO4

Ca Ca HNO3

Mg Mg H2CO3

31

(in water) (drain) (left in water)

The water is then sent to degasser where CO2 is removed. From degasser, water comes to

anion exchanger where anions are removed.

ROH + H2SO4 RSO4 + H2O

(Resin) HCl Cl (demineralised

HNO3 NO3 water)

(From cation exchanger) (Drain)

Water thus achieved is the required demineralised water which is then stored in

demineralised water storage tanks.

REGENERATIONRecharging the exhausted form of resin i.e. regeneration employing 5% of acid/alkali as

below:

Cation resin:

RNa + HCl RH + NaCl

K (fresh KCl

Ca resin) CaCl2

Mg MgCl2

(Exhausted resin) (removed by

rinsing)

Anion resin:

RSO4 + NaOH ROH + Na2SO4

Cl (fresh NaCl

NO3 resin) NaNO3

(exhausted resin) (removed by

rinsing)

The fresh resin thus produced is reused in demineralisation process.

32

WATER TREATMENT STAGE:-River (raw water) → Clarification → Filtration → Demineralization

CLARIFICATION AND FILTERATION OFWATER:-River water contains different impurities i.e.

Suspended impurities

Biological impurities

Soluble impurities

Colloidal impurities

WORKING:-

The raw water enters through valve and than chemicals is added.

Chlorine and alum are added. Chlorine is added to remove bacteria etc. Alums are

added to make the impurities heavier, once the impurities become heavier than a no. of

flocs are formed. By mixing the alums, heavy impurities are settle down due to gravity

and later removed. The time required for the formation of floc is called retention time

which is generally 3 hours but this can’t be achieved as it require large tank. In order to

cope up the limitation CLARRIFOCCULATION TANK is used.

This flocculation tank is consist of

1. Clarification zone

2. flocculation zon

After the addition of chemical the basic requirement arises is of mixing. Thus flash

mixers are used. Normally the chemicals mix naturally but when the raw water contains

much impurity than agitators are used to mix them.

Clarrifocculation tank has a central pillar which has four windows at 90

degree. The outer circle is half of windows so that level of water is arise then it flows

down through these windows into overflow channel. After mixing from flash mixer, the

water passes on to central pillar and follows the path as shown in fig. i.e. it moves to

max. floc area and comes out from window at 3.5 m height. The downward flow is

through perforated wall which sinks the raw water. Due to the long path a retention time

of 4 hour is easily available.

33

FIG-08 WATER TREANMENT PROCESS

34

FIG-9 CLORIFICATION SYSTEM, FIG-11WATER FLOW CYCLE

35

The capacity of water in this plant is 1000*1000 lt./hr. In flocculation

zone max. floc is formed and after removing it, the clear water moves into clarifier.

Some impurities are weightless and do not settle down so they are passed through filter

beds. There are two types of filter beds.

1. Gravity filter bed.

2. Forced filter bed.

In FORCED FILTER BEDS raisins are added to settle down the

impurities. In GRAVITY FILTER BEDS graded gravels are arranged. At bottom

gravels of big size are there and above other gravels are arranged according to size.

Above it grit and most of the above is sand.

The clarified water enters into sump. Sump is fully closed leaving one

window to see the level. Since it is fully closed hence no foreign matter can enter into it.

3.2 DEMINERALIZING PLANTWater is mainly used for cooling purpose of different parts like bearing winding etc.

in KaTPP. For this water should be Demineralized (D.M. water).

In this plant process water is freed from all dissolved salts. Equipments for

demineralization plant is supplied and erected by GE INDUSTRIAL (India) Ltd. .This

plant consists of two streams, each stream with activated carbon filter, weak acid, carbon

exchanger and mixed bed exchanger. The filter water goes to DM water plant through

250 dia header from where a header top off has been taken off to softening plant. Two

filtered water booster pumps are provided on filtered water line for meeting the pressure

requirement in DM plant.

When pressure drop across filter exceeds a prescribed limit from the activated

carbon filter enter works acid carbon unit. The dilation water enter the weak base anion

exchanger unit water then enters degassifier unit where free CO2 is scrubbed out of water

by upward counter flow of low pressure air flow through degassifier lower and degassed

water is pumped to strong base exchanger(anion –exchanger).

Arrangement for designing ammonia solution into dematerialized water after mixed bed

unit has been provided for pH correction before water is taken into the condensate

36

transfer pump the DM water to unit condenser as make up. The softening plant is a plant

designed to produce 100 cubic m/hr. of softened water per stream. It is using for bearing

cooling.

PH VALUE OFWATER:-

This is recommended to feed the water in the boiler at 25 degree

centigrade and pH value is 8.2 to 9.2 up to 28 days and the pressure is 59 Kg \cm2.

3.3 COOLING TOWER

It is used to reject heat into the atmosphere. There are two types of the cooling tower.

(1) Natural draft

(2) Forced draft

Natural draft tower used vary large concrete chimney to introduce air

through the media. They are generally used for water flow rate about 45000 m3 /hour. It

is used in utility power station.Here hight of cooling tower is 202M.

Forced draft tower utilize large fans to force or suck air through

circulating water. The water falls downward over fills surface which helps in increase the

contact time between the water and air. This held maximize heat transfer between two

media. Cooling rates depend upon fan diameter and speed. This type of tower much

wider used.

Here 2 NDCT used each of two units and hight of cooling tower is 202

meter.water tubes are used inside of cooling tower for cooling purpose.

This structure is constructed in r.c.c. shell poud floor and its derified water

channel c.w. For bay. The entire structure is supported combined circular rafting

constructed in different segments with slanted colomn fotting to support 17 m hight

circular sectional reckar colmns. This r.c.c. shell of 150 m dia. And 205 m height . It is

made of m 50 grade r.c.c. Which was also done at sight. There will be 200 colomns poud

floors that will generate cascading effect for cooling.

The cooling tower shell be capable of cooling the rated quality of water

37

through the specified thermal range at the design wet bulb temperature.

Minimum grade of concrete to be used for all the structure elements as :

Structure minimum grade

Foundations M 30

Basin M 35

Diagonal colomn M 40

Shell M 35

Precast work M 35

Foundations:

The design and construction of cooling tower foundations shell be in accordance with the

requirments continuous foundations shell be provided for cooling tower more then 75 m

height. The foundation is design for loadis indicated in as follows:-

A.) Thermally induced local loading

B.) Cold water basin floor loading

C.)Surface charge load of 15 KN per 50m

The basin floor at each compartment should be sloped towards a collecting sump for

effectively drainage the water to permitt desilting. To minimize the obstruction in flow

of water only the colomns supporting the fill structure shell be projected above the basin

floors.

BEARING COOLINGWATERWater from river comes in plant heat exchanger, where its temperature

cools down and that goes in AHP to make slurry. There are 480 plates’ exchangers. BCW

requirements of boiler and turbine auxiliaries of both the units is meet from BCW soft

water overhead tank with the capacity of 2000 cubic meter

38

FIG-10 COOLING TOWER

39

DEAERATOR:-DEAREATION OF FEEDWATER:-

In deareation dissolve gases such as oxygen & CO2 are expelled by

preheating the feed water before it enters the boiler. All natural water contains dissolve

gases in solution (i.e. oxygen + CO2) are released when water heated.

CONDENSER:-In condenser steam changes into water. The basic requirement is to

remove latent heat from the steam which is removed by another water (clarified water)

when it accepts the latent heat and becomes hot, than it is passed to cooling tower. In

cooling tower the water is cooled and then mix with river water.

PUMPS:-The entire green colored instrument is pumps which are 18 in no. to further pass the water.

1. FILTERWATER TRANSFER PUMP:-It is soft section consisting two types:-

BEARING COOLINGWATER PUMP:-

All the bearing temperature is controlled through oil bath and filter

water is used. Oil is used to cool the supplied water. Here doesn’t used raw water

because at the time of puncture it enters in the machinery part and small impurity may

stop the operation.

CONDENSATEWATER PUMP:-

This pump is coupled with blue colored motor. In order to couple it with

motor a little opening is left through which water leaks out when pumped

2. FILTERWATER TRANSFER PUMP:-This pump transfers water to D.M. plant. These pumps are in D.M.

section.

3.POTABLE WATER PUMP:-These pump pumps clear water for potable

purpose for whole plant.

40

3.4 H2 GENERATING PLANT

Hydrogen gas is used for cooling purpose for rotor of the generator. For

cooling purpose we have to use 99.9% pure hydrogen. To avoid fire so we have to apply

Hydrogen cooling. It is very difficult to generate and store the Hydrogen gas because it

is very explosive. Hydrogen as a coolant has the following advantages over air:

1. More efficiency and less noise.

2. Better Cooling.

3. More life and less maintenance.

4. Less chance of fire hazard.

5. Better rating.

GENERATING PLANT:-Hydrogen gas is produced by electrolytic dialysis by mixing KOH in D.M. water.

This reaction is done in electrolyser where Anode and Cathode are applied. Anode plate

is used for collecting H2 and Cathode plate is used for collecting O2. For electrolytic

dialysis 3000 Ampere current is passed into electrolyser. O2 is released to atmosphere

and H2 is sent to next machinery for further treatment.

COLLECTING PROCESS:-H2 Gas from electrolyser → Refrigerator for cooling → Separator to separate the

moisture → Compressor → Catalytic purifier → Dryer (Al2O3) → H2 cylinder. In

compressor H2 is treating in three steps where pressure is raised up to 130 Kg/cm2. In

dryer Alumina is used to absorb moisture.

CAPACITY:-In KaTPP the full day capacity of H2 generating is Not calculated because plant

is in on constraction.its appxi 40 cylinders per day. But in plant per day utilization are

of 15 cylinders. Per cylinder capacity is 200-250 kg and stored H2 is 99.8% pure.

41

CHAPTER-04 STG SYSTEM

4.1 BOILER

Boiler can simply defined as the device where any liquid is boiled or Boiler

may be defined as a device that is used to transfer heat energy being produced by burning

of fuel to liquid, generally water, contended in it to cause its vaporization. Boiler, in

simple terms, can be called “Steam Generator”. The following are factors essential for the

efficient combustion usually referred as “The three T’s”.

A) TIME – It will take a definite time to heat the fuel to its ignition temperature and

having ignited, it will also take time to burn.

B) TEMPERATURE – A fuel will not burn until it reaches its ignition temperature.

C) TURBULENCE – Turbulence is introduced to achieve a rapid relative motion

between the air and fuel particles.

CLASSIFICATION:

Boilers may be classified under different heads on different basis:-

1. Depending upon “Use”

1.1. Stationary (land) boilers

1.2. Mobile boilers

1.2.1. Marine boilers

1.2.2. Locomotive boilers

2. Depending upon “Tube contents”

2.1. Fire tube boilers

2.2. Water tube boilers

3. Depending upon “Tube shape”

3.1. Straight tube boilers

42

3.2. Bent tube boilers

3.3. Sinuous tube boilers

4. Depending upon “Tube position”

4.1. Horizontal or Vertical

4.2. Inclined

5. Depending upon “Furnace position”

5.1. Externally fired

5.2. Internally fired

6. Depending upon “Heat source”

6.1. Solid, liquid or gas

6.2. Waste of chemical process

6.3. Electrical energy

6.4. Nuclear energy

7. Depending upon “Circulation”

7.1. Natural circulation

7.2. Positive or forced circulation

A boiler is an enclosed that provides a means for combustion heat to be

transfer into water until it becomes heated water or steam. Its volume increases 1600

times. The process of heating a liquid until reaches its gaseous states its called

evaporation. The boiler system comprises of

feed water system

steam system

Fuel system

1. Feed Water system:-It provides water to the boiler and regulate feed according to demand.

2. Steam system:-

43

It collects and controls the steam produced in the boiler steam are

directed through a piping system to a point of use. Steam pressure is regulated using

valves and checked with pressure gauges.

3. Fuel system:-Fuel system includes all equipments used to provide fuel to generate the

necessary heat for higher boiler efficiency feed water is preheated by economizer using

the waste heat in the flue gases.

WATER TUBE TYPE BOILER USED IN KaTPPWITH 97M HIGHT

Various motors use in boiler are different rating and parameters

32KW ,15KW,11KW,&3.3KW

Parameter in 15KW motor

BOILER MOTOR DATA

Manufacturing CQ.GEAR BOX LTD.CHAINA

Motor rating 15KW

Speed 970rpm

Rated voltage 416V

Rated current 28.4A

Impedance voltage 80.0%

Oil waight 20kg

Core+winding waight 224kg

Total waight 600kg

Temp rise 50-55deg cel.

44

FIG-11 FLOW OF WATER & STEAM ,FIG-12 KaTPP BOILER

45

BOILER AUXILIARIESEfficiency of a system is of most concerned. Thus it is very important to maintain a

system as efficient as possible. Boiler auxiliaries help in improving boiler’s efficiency.

Following are the important auxiliaries used

ECONOMIZER: Its purpose is to preheat feed water before it is introduced into boiler

drum by recovering heat from flue gases leaving the furnace.

SUPER HEATER: It increases the temperature of steam to super heated region.

REHEATER: It is used for heat addition and increase the temperature of steam coming

from high pressure turbine to 540o.

SOOT BLOWER: It blows off the ash deposited on the water wall surface. It uses steam

for blowing purpose.

AIR PREHEATER: It pre-heats the air entering the furnace by recovering heat from

flue gases in order to ease the combustion process.

DRAFT FANS: They handle the supply of air and the pressure of furnace.

OIL GUNS: They are used to spray oil to raise the temperature of furnace to ignition

temperature of fuel.

WIND BOX: It distributes the excess air uniformly through out furnace.

BOILERMOUNTINGSThese are used for the safe operation of boiler. Some examples of mountings used are

water level indicator in drum, furnace temperature probe, reheat release valve, pressure

gauges indicating steam pressure etc.

46

4.2 TURBINE

Turbine is an m/c in which a shaft is rotated steadily by the impact of

reaction of steam of working substance upon blades of a wheel. It converts the potential

energy or heat energy of the working substance into mechanical energy. When working

substance is steam it is called ‘Steam Turbine’

In the steam turbine the pressure of the steam is utilized to overcome

external resistance and the dynamic action of the steam is negligibly small.

PRINICIPLE:-Working of the steam turbine depends wholly upon the dynamic action

of steam. the steam is caused to fall with pressure in a passage of nozzle, due to this fall

in pressure, a whole amount of heat energy is converted into mechanical energy &

steam is set moving with the reactor velocity. The rapidly moving particle of steam

enter the moving part of turbine and here suffers a change in the direction of motion

which gives rise to change of momentum and therefore to a force. This constitutes a

driving force to a machine.

The passage of the m/c through the moving part of the turbine commonly

called the blade, may take place in such a manner that the pressure at the outlet sides of

the blade is equal to that of the inlet side. Such a turbine is broadly termed as outlet

turbine or Impulse type

On the other hand, the pressure of the steam at outlet from the moving

blade may be less than that at type inlet side of the blade. The drop of pressure suffered

by the steam during its flow through the moving blades causes a further generation of

kinetic energy within the blades and adds to the propelling force which is applied to the

turbine rotor, such a turbine is broadly termed as Reaction Turbine.Here in kalisindh

thermal N600-16.7/587/537,Re-Het,Three Casing Four Exhaust,Tandem Compound

Condenser Type Turbine Used.

47

TURBINE SPECIFICATION: -

Rated output with extraction flow- 600MW

Speed - 3000rpm

Main steam throttle flow at HP Inlet - 1848.5 TPH

Main steam pressure to HP turbine

inlet -

167kg/sq.-cm.

Main steam temp.to HP turbine inlet - 538 deg.cel

Re-heater steam flow at IP inlet- 1587.942 TPH

Re-heater steam temp. at IP inlet - 538 deg.cel

Steam pressure at LP inlet - 35.12 kg/sq-cm

Steam flow at LP inlet- 1353.7 TPH

Rotation direction(view from turbine)- anticlock wise

Number of stages- 42

High pressure turbine -(a)intermediate pressure-(b)low pressure turbine-(c)governing sys

1 governing,& 8 pressure5 pressure stage2x2x7 pressure stageDEH(digital electro hydrolic)

Inlet steam flow governing type- nozzle +throttle

Rated exhaust pressure – 0.09kg/sq-cm

Type of bearings turbine - 6 journal +1 thrust

Turbine allowable frequency - 47.5 to 51.5 Hz

Turning gear rotation speed - 1.5 rpm

Ist critical speed of HP &LP rotor - 1722rpm

Ist critical speed of LP-A rotor- 1839rpm

Ist critical speed of LP-B rotor - 1903rpm

Heat regenerative extraction system – 3 HP heater +1 deaerator +4 LP heater

Final feed water temp.- 274.9 deg.cel.

Maximum bearing vibration- 0.076 m

Maximum allowable exhaust temp.- 80 deg.cel.

Cooling water design flow at

condenser-

70200TPH

48

FIG-13 (1)TURBINE DIAGRAM ,FIG-14 HP & LP ROTOR

49

4.3 GENERATOR

FIG-15 GENERATOR DIAGRAM

Generator is the main part of thermal power station or any power plant.

A generator is a machine which converts mechanical energy into electrical energy.

The generator has gas cooling construction enclosing the stator winding,

core and hydrogen coolers .The cooling medium hydrogen is contained within the frame

and circulation by fans mounted on either ends of the rotor .The generator is driven by

directly coupled steam turbine at a speed of 3000 rpm.

Provision has been made for circulating the cooling water in order to

maintain a constant temperature of the coolant i.e. H2 as measured at the fan section side

which is in touch with the temperature of the winding, core and other parts as per load.

Each of the 2 units have been provided with 3-phase turbo generator rated

output 706MVA, 18.525KA, 22KV, 0.85 lagging p.f., 984 rpm and 50 cycles/sec .The

generator has closed loop of hydrogen gas system for cooling of the stator and rotor at a

pressure of 4.5kg/sq-cm(g). is filled in a gas tight outer casing of the generator. H2 gas

circulates inside the casing by two single stage rotor mounted fans on either side of the

50

rotor .The heated H2 is in turn cooled by six surface type water coolers axially mounted

inside the generator casing .The cooling water is supplied to H2 coolers from the BCW

over head tank.

Each generator has terminal led out of its casing and a star point is

formed by sorting the neutral side terminals by a sorting bar. The neutral is grounded by

a 1-phase 11000/220V, Neutral grounding transformer, whose secondary coil is

laminated by laminated strip with mechanical ventilating holes, is connected across a

650V, class 0.4 ohm, 50 kW neutral grounding resistors and relays for protection of

generator against stator earth faults and stator in turn faults (rating 1 amp).

The H2 gas inside the generator casing is prevented from leaking in

between the rotor and shields, by a continuous oil film maintained between the rotor

and sealing rings .The shaft sealing system have two independent oil sources associated

pumps, regulators, coolers filters, electrical controls and alarm system. Two

independent oil sources are provided for air side and H2 side sealing rings. The oil

circuit of the H2 side of the shaft seal is closed and the oil is vacuum treated.In KaTPP

QFSN-600-2-22F type turbine used.

GENERATOR SPECIFICATIONS FOR UNIT I & II:-Make CQ GEARBOX chinaType QFSNApparent Output 706MVAActive Output 600 MWPower factor 0.85 laggingRated voltage 22 KVRated current 18525 Amp.Rated speed 3000 rpmFrequency 50 HzPhase connections Double gen. starInsulation class F(temp limited in B class)Cooling mode H20-H2-H2Rated H2 pressure 4.5kg/sq-cmExcitation type static thyristor excitationTerminal in generator 6

51

FIG-16 STEAM OVERVIEW

4.4 DIESEL-GENARATOR SET

It is used to emergency porpuse to supply auxillary system of power plant. 3 Set

Diesel generator are use in which 1 is standby.parameters of generator are as

MAKE BY STAMFORD MAHARASTRA INDIARATING 1900KVASPEED 1500rpmRATED CURRENT 2643.37ARATED TEMP. 40Deg celAMPS. 3.6AEXCITATIONVOLTAGE

63V

VOLTAGE 415VP.F. 0.8

FREQUENCY 50HZPHASE 3INSULATION CLASS H

52

CHAPTER-05 TRANSFORMER & SWITCHYARD SYSTEM

5.1 TRANSFORMER

Transformer is made up of following parts:-

1. Core

2. Winding

3. On load tap changer

4. Tank

5. Bushing

6. Auxiliary equipment

7. Insulating Oil

8. Cooling system

In KaTPP there are various transformers for various purposes. They are:-

1.Generating Transformer(GT)

2.Unit Transformer(UT)

3.Unit Auxiliary Transformer(UAT)

4.Inter Connecting Transformer(ICT)

5.Unit Service Transformer

6.Station Transformer

GENERATING TRANSFORMER:-At KaTPP , 3 single phase GT Installed for each phase in single unit.output of generator

has step up up to 400KV by GT.In KaTPP 150/200/250MVA,22.98/22 KV, G T are

used.

53

SPECIFICATIONS:-MANUFACTURING CROMPTON GREAVES LTD MUMBAI

RATING 250MVA

NOMINAL VOLTAGE(NO LOAD) HV-243.37KV

LV-22KV

RATED CURRENT HV-1031.0A

LV-11363.6A

PHASE 1

FREQUENCY 50HZ

TYPE OF COOLING

RATING (MAV)

ONAN ONAF OFAF

150 200 250

TEMP. 50deg cel

TEMP.RISE IN WINDING 50-55 deg cel

CONNECTION SYMBOL YND

MASS CORE+WINDING 12.5800kg

OIL MASS 58300/66600kg/ltr.

TOTAL MASS 251800Kg

NO LOAD LOSS 105KW

ON LOAD LOSS 483KW @249KVA

COOLING LOSS 15KW

OLTC (ON LOAD TAP

CHANGER)TAPPING RANG

+7.5 %TO -12.5 % IN STEPS OF 1.25%

ON HV NEUTRAL SIDE

HV/LV 1-1/2-2

54

SINGLE LINE CONNECTION DIAGRAM FOR 3xSINGLE PHASE GT

1N 1U1 1V1 1W1

1-2 1-1 1-1 1-1

2U1 2V1 2W1

2-1 2-1 2-1

2-2 2-2

55

FIG-17 1 .GT 2.U.T 3. UAT

56

UNIT TRANSFORMER:-

Unit Transformer are installed to fed supply to HT switchgear.there are two

80MVA Transformer installed near GT which are fed throw main busducts coming

from generator and fed to the HT switchgear.After step down THIS SUPPLY UP TO 11

KV HT switchgear used to supply on the major auxillary of the plant like

BFP,CWP,ID,FD,PA fens etc.The unit transformer is used to HT switchgear and it

supply voltage 22/11KV to UAT and different motors in boiler.UT is rated for

48/64/80MVA,22/11.6/11.6KV , Dyn11yn11 type winding. This permit to voltage

dowan up to 11KV.it have 2 radiator.

SPECIFICATIONS:-Manufactured BHARAT BIJLEE LTD. MUMBAI

Total no. provided 2

Type of construction CORE

Rated output 48/64/80 MVA

Rated voltage at no load 22/11.6/11.6KV

Phase HV/LV1/LV2 3

Frequencycy 50 Hz

Oil Temp. Rise 50deg cel

Winding Temp. Rise 50-55 deg cel

Connection symbol Dyn11yn11

Insulation level p.f/impulse

H V 50KV(rms)/125KVp

LV1-LV2 28KV(rms)/75KVp

LVN1-LVN2 28KV(rms)/75KVp

Winding +core mass 47500kg

Mass/volume of oil 23300/27100 kg/ltr

Total mass 107000kg

57

SINGLE LINE DIAGRAMLV1

2N1S2 2 2 2

CORE1

2N1S1

1 1 1

2N2S2 2V1S2

CORE2 WTICT

2N2S2 2V1S1

NCR 2N2 2U1 2V1 2W1

LV2

2N1S11 2 2 2

CORE1

2N1S12

1 1

2N2S21 2V1S22

CORE2 WTICT

2N2S22 2V1S11

NCR 2N2 2U2 2V2 2W2

1U 1V

1W

1U1S1 1V1S1

1W1S1

CORE1 CORE 1

CORE 1

1U1S2 1V1S2

1W1S2

1U2S1 1V2S1

1W2S1

CORE2 CORE2

CORE2

1U2S2 1V2S2

1W2S2

1U2S1 1V3S1

1W3S1

CORE3 CORE3

CORE3

1U3S2 1V3S2

1W3S2

1V1S1

WTICT

1V1S2

58

UNIT AUXILLIARY TRANSFORMER:-

There is one more Transformer known as Station Transformer used only for initializing

the start-up of the station (Main Plant).It is very beneficial during emergency situations

such as tripping of Units, shut-down etc.

In KaTPP 2 UAT used for step down voltage 11/3..3KV supply

used to switchgear equipments.

INSTRUMENT TRANSFORMER:-Instrument transformer have wide range in application such as

measurement of voltage, current, power & energy power factor, frequency. It is also

used for protection circuit of the power system for operation of over current, under

voltage, earth fault and other type of relays, The instrument transformer can be

classified as

(A). CURRENT TRANSFORMER:-

Current transformer is used for monitoring the current for the purpose of

measuring and protection.The dead tank current transformer accommodate the

secondary cores inside the tank which is at ground potential. CT used current ratio

1000:1 and range is 1A-5A.

(B). POTENTIAL TRANSFORMER:-

The function of P.T. is to step down the voltage so that it can be

measured by standard measurement.Output in pt is 110V.The transformer is generally

core type and form Y-Y group and having the insulation as oil and papers.

59

CHAPTER-06,ESP & ASP SYSTEM

6.1 ELECTRO STATIC PRECIPITATORIf suspended particles are not removed from the flue glass, and it is allowed

to be released in environment, then it would cause a serious threat to the environment, so

it becomes necessary to extract suspended particles from the flue glass and for this

purpose ESP is widely used. Precipitation of ash has another advantage too. It protects

the wear and erosion of ID fan. To achieve the above objectives, Electrostatic Precipitator

(ESP) is used. As they are efficient in precipitating particle form submicron to large size

they are preferred to mechanical precipitation.

WORKING PRINCIPLE:-An electrostatic precipitator is defined as a device which utilizes

electrical forces to separate suspended particles. The electrostatic precipitator consists

of two sets of electrodes , one in form of thin wire called “discharge or emitting

electrode” and other set is called “collecting electrode” in there form of plate ESP

POWER SUPPLY COMPONENT .

CONSTRUCTION:-The main parts of ESP are as follows:-

Casing

Hoppers

Collecting system

Emitting system

Rapping mechanism for collecting system

Rapping mechanism for emitting system

60

Insulator housing

CASING:-

It is designed for horizontal gas flow to provide for heat expansion, the casing is

supported by roller bearing support.

HOPPERS:-

They are of pyramidal shape .Angle between hopper corner and Hz is never less than 55

degree.

COLLECTOR SYSTEM:-

The profiled collecting electrode is based on the concept of dimensioned electrode

stability .The upper plates have hooks and lower edge has a receiving plate.

EMITTING SYSTEM:-

The framework is thoroughly braced and forms a rigid box like structure, the emitted

electrode is made of hard stainless steel wires.

RAPPING MECHANISM FOR COLLECTING SYSTEM:-

The system employs fumbling hammer which are mounted on an Hz. Shaft in a

staggered fashion .A uniform rapping effect is provided for all collecting plates in one

row .Rapping frequency is very low to minimize the dust loss. The hammers are

operated by motor, so that they strike the plate at fixed frequency.

61

6.2 ASH HANDLING PLANT(A.H.P)

The ash produced on the combustion of coal is collected by ESP. This ash is now

required to be disposed off. This purpose of ash disposal is solved by Ash Handling Plant

(AHP). There are basically 2 types of ash handling processes undertaken by AHP:

· Dry ash system

· Ash slurry system

DRY ASH SYSTEMDry ash is required in cement factories as it can be directly added to cement. Hence the

dry ash collected in the ESP hopper is directly disposed to silos using pressure pumps.

The dry ash from these silos is transported to the required destination.

ASH SLURRY SYSTEMAsh from boiler is transported to ash dump areas by means of sluicing type hydraulic

system which consists of two types of systems:

Bottom ash system

Ash water system

BOTTOM ASH SYSTEM

In this system, the ash slag discharged from the furnace is collected in water impounded

scraper installed below bottom ash hopper. The ash collected is transported to clinkers by

chain conveyors. The clinker grinders churn ash which is then mixed with water to form

slurry.

ASHWATER SYSTEM-

In this system, the ash collected in ESP hopper is passed to flushing system. Here low

pressure water is applied through nozzle directing tangentially to the section of pipe to

create turbulence and proper mixing of ash with water to form slurry. Slurry formed in

above processes is transported to ash slurry sump. Here extra water is added to slurry if

required and then is pumped to the dump area.

FLY ASH SYSTEM

62

Even though ESP is very efficient, there is still some ash, about 0.2%, left in flue gases. It

is disposed to the atmosphere along with flue gases through chimney.

FIG-18 ASH HANDLING SYSTEM

63

CHAPTER-07,SWITCHYARD , C & I SYSTEM

7.1 SWITCH YARD

Switchyard is considered as the HEART of the Power Plant. Power

generated can be worthful only if it is successfully transmitted and received by its

consumers. Switchyard plays a very important role as a buffer between the generation

and transmission. It is a junction, which carries the generated power to its destination (i.e.

consumers). Switchyard is basically a yard or an open area where many different kinds of

equipments are located (isolator, circuit breaker etc…), responsible for connecting &

disconnecting the transmission line as per requirement (e.g. any fault condition). Power

transmission is done at a higher voltage. (Higher transmission voltage reduces

transmission losses).

Both units is 22KV in KaTPP. stepped-up to 400KV by the Generating transformer &

then transmitted to switchyard. Switchyards can be of 400KV, & 200KVIn SSTPS there

are two interconnected switchyards:-

(i) 400KV SWITCHYARD

(ii) 220KV SWITCHYARD

The 400KV & 220KV switch yard have conventional two buses arrangement with a bus

coupled breaker. Both the generator transformer and line feeder taking off from switch

yard can be taken to any of the two buses, similarly two station transformer can be fed

from any two buses. Each of these line feeders has been provided with by pass isolators

connected across line isolators and breaker isolators to facilitate the maintenance of line

breaker. Each 400KV & 220KV lines have provision of local break up protection. In

event of breaker which corresponding to bus bar differential protection scheme and trips

out all the breakers and connected zone bus bars differential protection scheme for bus I

& II. All the breaker of the connected zone and bus coupler, breaker will trip in event of

fault in that zone. Here in KaTPP 4 out going line are as below:-

1.400KV TO BTAWDA

2.400KV TO BTAWDA

64

3.220KV TO JHALAWAR

4.220KV TO JHALAWAR

Each of the two bus bars has one P.T. one for each phase connected to it. Potential

Transformer are make in CROMPTON LTD. Each time line feeders has two nos. Core

for each phase capacitor voltage Transformer. for metering and protection are

multicored single phase, oil filled, nitrogen sealed and are provided at rate of one per

phase.-

FIG-19 SWITCHYARD

65

400KV SWITCHYARD :There are on total 21 bays in this switchyard.

(A bay is basically a way for the incoming power from generator as well as outgoing

power for distribution).

3 for unit Generating Transformer.

2 for various distribution lines such as:

BTAWDA LINE

2 for Bus coupler.

2 for TBC.

2 for ICT.

1 for the Bus Section.

There are on total 2 buses in 400KV switchyard.

Bus-1

Bus-2

There are two transfer buses:

Transfer bus-1

Transfer bus-2

Transfer buses are kept spare and remain idle and are used only for emergency purposes.

BUS COUPLER-1 interconnects Bus-1 & Bus-2, respectively. Bus couplers are very

beneficial as they help in load sharing between the different buses.

TBC (TRANSFER BUS COUPLER):

TBC is a bus coupler, which uses transfer bus when there is any defect in the equipments

used (circuit breakers & isolators) in any of the bay. Thus, it offers a closed path through

transfer bus for the flow of power in the respective bus.

A described of electrical equipment at 400KV & 220KV system are as follows: -

Circuit Breaker(VCB& SF6)

Isolators

Current Transformers(C.T.)

Potential Transformers(P.T.)

Lighting Arresters

66

Earthing Arresters

Capacitor Voltage Transformers(C.V.T.)

Inter connected transformer (ICT)

CIRCUIT BREAKER:-

FIG-20 CIRCUIT BREAKERIt is an automatic controlling switch used in power house, substation & workshop as well

as in power transmission during any unwanted condition (any fault condition-earth fault,

over-current, flashover, single phasing,). During such condition it cuts down the supply

automatically by electromagnetic action or thermal action. It can be used in off-load as

well as on-load condition. When a circuit breaker is operated by sending an impulse

67

through relay, C.B. contact is made or broken accordingly. During this making and

breaking, an arc is produced which has to be quenched; this is done by air, oil, SF6 gas

etc….

Depending on the medium being used C.B.s can be categorized into various

types.PLANT for 400 KV/220 KV switchyard only 4 main types are being used:-

ABCB (Air operated circuit breaker):- operated as well as arc quenched through air.

Air operated SF6 circuit breaker:- operated through air but arc quenching done

through SF6 gas.

MOCB (Minimum oil circuit breaker):-operated through spring action but arc

quenching done through oil (Aerosol fluid oil).

Hydraulic operated SF6 circuit breaker:- operated through hydraulic oil and arc

quenching done through SF6 gas. Hydraulic operated SF6 circuit breaker is the most

efficient due to following reasons:-

1. Less maintenance.

2. Arc quenching capability of SF6 gas is more effective than air.

3. Heat transfer capacity is better in this C.B.

Here we use SF6 provided for each stage are SIEMENS made and rated for

420KV/245KV, 3150A Each pole has three interrupters which are oil filled with SF6 gas

at 7.5 Kg/sq. cm.Here in KaTPP 3AP1FI/3AP2FI type CB are used for 400KV &220KV

Switchyard.

Interlock Scheme of Circuit Breaker: -

Generator Breaker

Station Transformer Breaker

Line Feeder Breaker

Bus Coupler Breaker.

PARAMETERS FOR CBParameters 400KV yard For 220KV yard

Type 3AP2FI 3AP1FI

Rated voltage 420KV 245KV

Rated lighting impulse withstand

voltage

1425KVp 1050KVp

68

Rated power frequency withstand

voltage

610KV 460KV

Frequency 50Hz 50Hz

Rated nominal current 3150A 3150A

Rated short circuit breaking current 50KA 40KA

Rated short circuit time duration 3 sec 3 sec

Rated out of phase breaking current 12.5A 10KA

First pole to clear factor 1.3 1.3

Rated single capacitorbank break

current

400A 125A

Rated line charging break current 600A 400A

DC component 46% 25%

Rated operation sequence o-.3s-co- 0-.3S-CO-3M-CO

Rated pressure of SF6 at+20deg cel 3min-c0

Weight of SF6 6.0 bar rel 6.0bar rel

Total weight 39kg 22kg

Control voltage 5400kg 3000kg

Operation machnisiom/heating voltage 220V DC

240V AC

220V DC

240V AC

ISOLATERS:-An isolator is also a switching device used to disconnect the line. As the

name suggests it isolate the line from the supply. It is always used in OFF-LOAD

condition. Whenever any fault occurs in the equipments present in the line, in order to

remove the fault or replace the device first of all supply is disconnected. But even after

the disconnection of the supply, the line remains in charged mode so before working on

the device (to remove fault) isolator should be made open. Depending on the structure

there are mainly two types of isolators:-

Pentagraph isolator.

Centre-break isolator (also known as Sequential isolator).

69

Pentagraph is generally used in buses whereas Centre-break (Sequential) is used in line.

Isolators may be operated in air (pneumatic), electrically or even manually.

In KaTPP M.O.M/ISOLATOR use for 400/220 KV its various parameters are as

Type VBManufacturing by GR-power switchgear ltd HyderabadRated voltage 420/245 KVRating 400/200AImpulse voltage 1050KVpTotal weight 1300/950kgShort time current 40KA for 3 secControl voltage 220V DC

LIGHTENING ARRESTER:-It is a protective device, which protects the costly equipments such as

overhead lines, poles or towers, transformer etc. against lightening. As the name suggests

it arrests the lightening of very high voltage (crores of KV) and dump it into the ground.

It works on the principle of easy path for the flow of current. L.A. is connected in

parallel with the line with its lower end connected and the upper end projected above the

pole of tower.

LIGHTENINGMOST:

It is present at the highest point, at the topmost tower of the switchyard and is connected

together by wires forming a web. The reason for its presence at the topmost point is to

grasp the lightening before it can come, fall and damage the costly equipments present in

the switchyard.

FI

G-21 LIGHTING ARRESTER

70

SPECIFICATIONS OF LIGHTENING ARRESTER:-Type A

Maximum Voltage 245KV

MAX Current 2000A

RELAY Maximum Current 40A

Rating 165KW

Total weight 215kg

EARTHING ISOLATORS:-The term ‘Earthing’ means connecting of the non-current carrying parts

of the electrical equipment or the neutral point of the supply system to the general mass

of earth in such a manner that all times an immediate discharge of electrical energy

takes place without danger. An Earthing isolator is a large value of capacitance. This

can be charged up to line voltage. Earthing isolator is used to discharge the line

capacitance and work on it.

WAVE TRAPER:-

It is an equipment used to trap the high c arrier frequency of 500 KHz and above and

allow the flow of power frequency (50 Hz). High frequencies also get generated due to

capacitance to earth in long transmission lines. The basic principle of wave trap is that it

has low inductance (2 Henry) & negligible resistance, thus it offers high impedance

to carrier frequency whereas very low impedance to power frequency hence allowing it to

flow in the station.

FIG-22 WAVE TRAPER

71

CURRENT TRANSFORMER:

FIG-23 CURRENT TRANSFORMERThis Transformer is used for basically two major functions: -

Metering which means current measurement.

Protection such as over current protection, overload earth fault protection, Bus-bar

protection, Bus differential protection.

NOTE: - Secondary of the C.T should be kept shorted because (when secondary is kept

open) even the presence of a very small voltage in the primary of C.T will prove to be

harmful as it will start working as a step-up Transformer & will increase the voltage to

such a high value that primary would not be able to bear it & will get burned.

CT used current ratio 1000:1 and range is 1A-5A.CT connected in series while PT in

parallel.

SPECIFICATIONS:for 220kv switchyardType 10SK-245/460/1050

Rated voltage 245KV

Frequency 50Hz

Current 40KA for 3 sec

Rated primary current 2000A

Continuos current 2400A

Insulation class A

Secondary terminal rating 2A

Oilweight 210kg

Total weight 850 kg

72

PIPRI LINE:

In the case of emergency, e.g. total grid failure we take the power from Pipri line for the

initial starting of the station (Main Plant).

CAPACITOR VOLTAGE TRANSFORMER(CVT)

FIG-24 CVT

This Transformer performs mainly two major functions:-

Used for voltage measurement. The high voltage of 400 KV is impossible to measure

directly. Hence a C.V.T is used, (connected in parallel with the line) which step-downs

the voltage of 400 KV to 110 KV, comparatively easy to measure.

The other most important function of C.V.T is that it blocks power frequency of 50Hz

and allows the flow of carrier frequency for communication.Each of the four line feeders

provided with three capacitor volt transformer for metering and synchronizing.

P.T (POTENTIAL TRANSFORMER):This Transformer is connected in parallel with the line with one end earthed. It is only

used for voltage measurement by stepping-down the voltage to the required measurable

value.

SPECIFICATIONS:

PARAMETERS

Type

FOR 400KV

CVE/420/1425/50

FOR 220KV

CVE/245/1050/40

HV 420KV 245KV

73

Frequency 50Hz 50Hz

Insulation level 440kv/1425KVp 440KV/1050KVp

Voltage factor 1.2 CONT/15-30 SEC 1.2 CONT/15-30 SEC

Equilant capacitor 4400+_10%, -5% P.F 4400+_10%, -5% P.F

Primary capacitor C1 4885 PF NOMINAL 4885 PF NOMINAL

Secondary capacitoe C2 4455 PF 4455 PF

Total burden/class 100VA/0.2 100VA/0.2

Thermal burden 300VA 300VA

Capacitor oil mass 50+_10%kg 50+_10%kg

Equipment oil mass 95+_10% kg 95+_10% kg

Total weight 625+_10%kg 625+_10%kg

NOMINATION OF CVT

A-NHF 1a1-1n 2a1-2n 3a1-3n

1a2-1n 2a2-2n 3a2-3n

22.98KV 63.32V 63.32V 63.32V

A

HV TERMINAL

C1 PRIMARY CAPACITOR

C2 SECONDARY CAPACITOR

NHF H F TERMINAL

L COMPENSATING CHOKE

N NEUTRAL

F1-F6 HRC FUSE

E EARTH SCREEN BETWEEN LV & HV

Zd DAMPING DEVICE

V VARISTOR

D DRAIN OIL

S SURGE ARRESTER

74

SINGLE LINE DIAGRAM OF CAPACITOR VOLTAGE TRANSFORMER

C1 LF1 1a1

C2F2 1a2

TrN HF 1n

F3 2a1

F4 2a22n

D S EsF5 3a1

F6 3a2N

3n E ZdV

75

INTER CONNECTED TRANSFORMER(ICT)Purpose of ICT is simply interconnection between 400KV and 220KV

Switchyard. 3xM1802-300/D-10.19.300MA2 Type autotransformer is used. manufactur

by CROMPTON GEARVES TRANSFORMER DIVISION BHOPAL.PARAMETERS

USE IN ICT:

Rating 315MVA,400/220/33KV

No load HV 400KV

Amperes LV 220KV

ONAN/ONAF/OFAF HV 272.8/363.7/454.6

LV 496.0/661.31/826.7

TV 1102/1470/1837.

Phase 3

Frequency 50Hz

Rating(MVA) ONAN ONAF ODAF

HV 189 252 315

LV 189 252 315

TV 63 84 109

Guaranted

temp.winding&oil

50 deg cel

Connection symbol YNaod11

Core+winding mass 120700kg

Total oil 71600/81800kg/ltr.

Total mass 287000kg

No load & on load

loss&auxil loss

100KW & 600KW,15KW

Impedence tolerance Hv-lv 12.55,hv-tv 45%,tv-lv 30%

77

FIG-25 ICT 2 MOISTURE SENSER 3. CONTROL BOX 4 BUCHOL RELAY 5 NEUTRAL CT 6 THREE PHASECONNECTION3.2.2 SINGLE LINE DIAGRAMOF INTERCONNECTED TRANSFORMER(ICT)

TAP CHANGER AUTO TRANSFORMER FOR HV/LV/TV

N 1U1 2U1 1V1 2V1 1W1 2W1

P2 P2 P2 P2N2S1 1U11S1 1V12S1 1W11S1CORE 2 CORE1 CORE 1 CORE1N2S2 1U11S2 1V12S2 1W11S2

1V12S3CORE 21V12S4

N1S1 1V11S2CORE1 WTICT/RTD/CTN1S2 1V11S1

K K K-12 +4 -12 +4 -12 +4

HV/LV

2.1 2.1 2.1

2U12S1CORE 22U12S22U12S3CORE 22U12S42U11S2 2V11S2 2W11S2WTICT/RTD/CT CORE 2 CORE 22U11S1 2V11S1 2W11S1

2 2 2

3U1 3V1 3W1

3U11S1 3V11S1WTICT/RTD/CT CORE

TV 3U11S2 3V11S2

3U11S3CORE3U11S41 1 1

2 2 2

78

3.3 SINGLE LINE DIAGRAM FOR LINES OUTGOING FROM KaTPP

SWITCHYARD

400KV LINE-03,DAHRA(NEAR ANTA,DIST-BARAN) (BAY-12)

BUS 1

BUS 2

89-12-01 89-12-01 89-12-02 89-12-02ISO OPEN ISO CLOSE ISO OPEN ISO CLOSE

ISO ISOGRND GRND

CB OPEN CB CLOSE CB OPEN CB CLOSE

CB CB

GRND GRND

89-12-03 89-12-03 89-12-04 89-12-04ISP OPEN ISO CLOSE ISO OPEN ISO CLOSE

ISO ISO

89-12-06 89-12-06 CB OPEN CB CLOSE 89-12-05 89-12-05ISO OPEN ISO CLOSE ISO OPEN ISO CLOSE

AC SUPPLY AC SUPPLYREALY REALY

ISO CB ISO

GRND GRND


ISO ISO

GRND GRND

DAHRA LINE-03 (BAY -12) GT(GENERATION TRANSFORMER)-2 (BAY-14)

79

400KV LINE-01,BTAWDA (BAY-05)

BUS 1

BUS 2


ISO ISOGRND GRND


CB CB

GRND GRND


ISO ISO


ISO

ISO CB ISO

CB GRND GRND


ISOISO ISO

GRND GRND

REACTOR

GT(GENERATION TRANSFORMER)-1(BAY-07)

REACTOR BAY -04

BTAWDA LINE-01(BAY-05)

80

400KV LINE-02,BTAWDA (BAY-09)

BUS 1

BUS 2


ISO ISOGRND GRND


CB CB

GRND GRND


ISO ISO


CB ISO CB ISO

GRND GRND


ISOISO ISO

GRND GRND

REACTOR

SPAHRE LINE-II

REACTOR BAY -08

BTAWDA LINE-02 (BAY-09)

81

400KV SPARE LINE, (BAY-01)

BUS 1

BUS 2

89-01-01 89-01-01 89-01-02 89-01-02ISO OPEN ISO CLOSE ISO OPEN ISO CLOSE GRND

ISO ISOGRND GRND


CB CB ISO

GRND GRND

89-01-03 89-01-03 89-01-04 89-01-04 GRNDISP OPEN ISO CLOSE ISO OPEN ISO CLOSE

ISO ISO


CVT BUS -01

CB ISO CB ISO

GRND GRND


ISO ISO

GRND GRND

CVT BUS-02

SPAHRE LINE,BAY-01

315 MVA ICT ,BAY-03

82

400KV TIE LINE, (BAY-02)

BUS 1

BUS 2


ISO ISOGRND GRND


CB CB ISO

GRND GRND


ISO ISO


CVT BUS -01

CB ISO CB ISO

GRND GRND


ISO ISO

GRND GRND

CVT BUS-02

TIE LINE,BAY-02

315 MVA ICT ,BAY-04

83

400KV ICT LINE , (BAY-03)

BUS 1

BUS 2


ISO ISOGRND GRND


CB CB ISO

GRND GRND


ISO ISO


CVT BUS -01

CB ISO CB ISO

GRND GRND


ISO ISO

GRND GRND

CVT BUS-02

ICT , BAY-03

315 MVA ICT ,BAY-05

84

220KV LINE -01 JHALAWAR (BAY -01)

BUS 1

BUS2

89-01-01 89-01-01 89-01-02 89-01-02

ISO OPEN ISO CLOSE ISO OPEN ISO CLOSE

ISOLATOR ISOLATOR

GAND GRND

CB LOCAL CB REMOTE CB OPEN CB CLOSE CB SPRING CHARGED

CIRCUIT BREAKER

89-01-03 89-01-03

ISO OPEN ISO CLOSE

ISO

GRND

89-01-04 89-01-04

ISO OPEN ISO CLOSE

ISO

TRANSFER BUS

220KV LINE-01JHALAWAR

85

220KV LINE-02 JHALAWAR (BAY -03)

BUS 1

BUS2

89-03-01 89-03-01 89-03-02 89-03-02


ISOLATOR ISOLATOR

GAND GRND


CIRCUIT BREAKER

89-03-03 89-03-03

ISO OPEN ISO CLOSE

ISO

GRND

89-03-04 89-03-04

ISO OPEN ISO CLOSE

ISO

TRANSFER BUS

220KV LINE-02JHALAWAR

86

220KV ICT(INTER CONNECTED TRANSFORMER) BAY -02

BUS 1

BUS2

89-02-01 89-02-01 89-02-02 89-02-02


ISOLATOR ISOLATOR

GAND GRND


CIRCUIT BREAKER

89-02-03 89-02-03

ISO OPEN ISO CLOSE

ISO

GRND

89-02-04 89-02-04

ISO OPEN ISO CLOSE

ISO

TRANSFER BUS

220KVLINE ICT

87

220 KV BUS COUPLER(BAY-05)

BUS 1

BUS 2

BUS 1 CVTBUS 2 CVT

89-05-01 89-05-01 89-05-02 89-05 -02ISO OPEN ISO CLOSE ISO OPEN ISOCLOSE

ISO ISO

GRNDGRND

CB LOCAL CB REMOTE CB OPEN CB CLOSE CB SPRINGCHARGED

CIRCUIT BREAKER

88

220KV TRANSFER COUPLER BAY-04

BUS 1

BUS 2

89-04-01 89-04-01 89-04-02 89-04-02


ISO ISO

GRND

CB LOCAL CB REMOTE CB OPEN CB CLOSE CB SPRINGCHARGED

CIRCUIT BREAKER

89-04-03 89-04-03

ISO OPEN ISO CLOSE

ISO

TRANSFER BUS

89

7.2 CONTROL & INSTRUMENTATION SYSTEM

7.2.1 SWITCHGEARThe apparatus used for switching, controlling and protecting the electrical

circuits and equipment is known as switchgear.

A switch gear is one which makes or breaks electric circuit. Numerous

problems arise in erection, testing and commissioning of switch gear and various

precautions are to be made in operating and maintenance of switch gear.

Essential Features of Switch Gear:-Complete Reliability

Absolutely certain discrimination

Quick operation

Provision for manual control

provision for instruments

The main components of indoor switchgear are given below:-

i.Bus-Bars

ii.Isolating Switches

iii.Current Transformers

iv.Potential Transformers

v.Circuit Breaker

vi.Earthing arrangement

vii.Relays

viii.Inter-Locking arrangements

(i) BUS-BARS:-Bus bars are defined as the conductors to which several incoming and

outgoing lines are connected. They are essential component of Switchgear. They are

made up of Cu. and Al. The type and designers of Switchgear depends upon rated

normal current and short circuit capacity. The Bus bars are enclosed in bus bar chamber.

In KaTPP there are two types of indoor switch gear:

11 KV &3.3KV or High tension

90

3.415V or Low tension

(ii) ISOLATING SWITCHING:-1. They are capable of-Interrupting the Transformer Magnetizing Current.Interrupting

line charging Current.Interrupting load Transformer Switching.

2. The main application is in connection with feed or bank Transformer feeders & there

units make it possible to switch out one Transformer while the other is still on load.

(iii) CIRCUIT BREAKER:-They are capable of breaking the circuit on faults. It is heavy duty

equipment mainly utilized for protection of various circuit and separation of loads.

The Circuit Breaker uses on a relay or by manual signal. The Circuit

Breakers which are used in Switchgear are VCB type.

(iv) EARTHED SWITCHES:-Earthed switch is connected between line conductor and earth. Normally

it is open when line is disconnected. The Earthing switched is closed so as to discharge

the voltage trapped on line for high voltage and so the capacitor between line and earth

is charged to high voltage. For maintenance work their voltage are discharged to earth

by closing the earth switch.

(vi) INTER-LOCKING:-The following type of inter- locking are provided

The Circuit Breaker must be in open position before it is lowered in this position.

The Circuit Breaker can be closed only raising the final plug in position.

The Circuit Breaker can be closed before raising plug in position.

Inter-locking between isolators, Earthing switches and Circuit Breakers are provided.

(vii) RELAYS:-A Protective Relay is a device that detects the fault and initiates the

operation of the circuit breaker to isolate the defective element from the rest of the

system.

91

7.2.2 PROTECTIONThe fault, which may occur in stator winding are-

1. Phase to phase fault.

2. Phase to ground fault.

3. Line to line fault.

4. Over heating.

These faults are due to-

1. Over voltage is because of system transients, lightening switching surges or sudden

loss of load.

2. Insulation deterioration due to any matter, moisture, corona discharge, Hardening of

solid and vibration.

It is very necessary to minimize the tripping time during any fault so that the lamination

is not damaged. The repairing being affected by replacing the faulty stator bar.A

delayed clearance may damage the lamination, so fire may be caused and partial re-

insulation of core may be necessary.

GENERATOR PROTECTION:-The Generator is required to be tripped or isolated on following types of fault:

1. Failure of generating insulation.

2. Failure of prime mover turbine or boiler.

3. Failure of generating auxiliaries such as hydrogen gas system,seal oil

system, cooling system, and cooling water system.

4. Failure of grid.

The tripping command to the GT breaker is given by master trip relay 866,

86GT, and 86GB. To make it feasible the master trip relay is connected to a common

bus. All the protection relays are connected in between the position of 220V.

D.C. PROTECTION AND THE COMMON BUS:-Protection device are that detect abnormal condition in electrical circuit

by measuring the electrical quantity which are different under normal and fault

condition. The basic electrical quantities are voltage, current, phase angle and frequency.

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The relay doesn’t operate for normal voltage, normal current, normal phase angle and

normal frequency.

Different type of protection can be listed as:

1. Current operated protection.

2. Different protection.

3. Voltage operated protection.

4. Impedance type protection.

5. Frequency type protection.

1. CURRENT OPERATED PROTECTION:-a. Generator differential protection.

b. Generator negative sequence protection.

c. Generator output current protection.

d. Generator stator earth fault protection.

e. Generator REF protection.

f. Generator standby earth fault protection.

g. UAT o/c protection.

h. Generator o/c and short circuit protection.

i. L.B.B. protection.

2. DIFFERENTIAL PROTECTION:-a. Generator overall differential protection.

b. UAT differential protection.

3. VOLTAGE OPERATED PROTECTION:-a. Generator over voltage protection.

b. Generator stator E/F protection.

c. GT over voltage protection.

d. PT’s voltage supervision protection.

e. Generator inter-turn fault protection.

4. IMPEDANCE TYPE PROTECTION:-a. Generator back up impedance protection.

b. Generator loss of exact protection.

c. Generator pole slip protection.

5. FREQUENCY TYPE PROTECTION:-a. Generator under protection Frequency.

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REQUIREMENT OF PROTECTIVE DEVICES:

Selectivity: Only that part of the installation containing fault should is disconnected.

Safety against faulty tripping: There should be no trip when there is no fault.

Reliability: The device must act within the required time.

Sensitivity: Lowest signal input value at which the device must act.

Tripping time: There should be a clear a distinction between the tripping time of the

device, considering the circumstances such as current and total tripping time for the fault.

7.3 CONTROL ROOMVarious measurements can be taken at the control room simultaneously.

The second important part of the control room is relay part. Various relays are provided

here BY AREVA LTD.

Fig-26 CONTROL ROOM

CONTROL ROOM PANELS:-

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FAN CONTROL DESK: -

ID Fan (Induced draft fan, 2nos.) at full load.

FD Fan (Forced draft fan, 2nos.) at full load.

PA Fan (Primary air fan, 2 nos.) at full load.

PRESSURE CONTROL DESK: -Furnace pressure (5-10mmwcl.)

Primary air header pressure (750-800mmwcl).

1. FUEL CONTROL DESK:-

Coal oil flow.

Oil pressure.

Temperature of mill (inlet or outlet)

Flow of air.

Drum level control, flow of steam water

Pressure of steam and water.

Temperature of steam and water.

1. TURBINE DESK:-

Pressure control, load mode control.

Speed control.

Ejector, control valves, stops valves and deviators.

1. GENERATOR CONTROL PANEL:-

Voltage, current, MVAR.

Stator, rotor temperature.

For stator cooling.

7.4 AUXILIARY SUPPLY

95

Electrical supply system is the most important part of the thermal power

station. The failure of even comparatively small equipment could result in the losing of

load or being put out of commission.

SOURCE OF SUPPLY: -

1. URGENT AUXILLARY: -

Those are associated with running of units whose loss would cause an

immediate reduction unit output.

2. SERVICE AUXILLARY: -

These are common auxiliaries associated with one or more units. There

loss would not affect the output of the unit after considerable time of interval.

ELECTRICAL AUXILLARY SYSTEM: -The KaTPP auxiliaries are operated at two voltages that are 6.6 KV and

415V. In respect of 6.6KV system, auto change over facility is provided for change over

of source of supply from unit station in the case of unit trip out. The station is having

the following auxiliary system: -

More then 1500KW connected on 11KV.

More then 200KW less then 1500KW connected on 3.3KV.

Less then 200KW on 415V.

220V D.C. underground system for use in control and protection system.

3.3 KV SYSTEM: -

For the running unit, the unit auxiliaries are normally fed from gen’r

itself through 11/3.3 KV, 15 MVA unit auxiliary transformers, which is, connected to

the unit switchgear viz. USA and USB. Power to station auxiliaries and by unit

auxiliary is fed from 220/3.3KV, 50 MVA station transformers through two switchgear

viz.

415 V SYSTEMS: -

For driving ten 100W motors and other accessories, we need 415V

supply. For this purpose various transformer are used to step down 3.3 KV to 415V at

various places. Oil circuit breaker is provided between 3.3 KV bus and primary winding

of transformer.

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This system is three phase, 4-wire solidly grounded system is made

available for 1000 KVA, 3.3 KV/ 433V transformer.

240 V SYSTEMS: -240 V, 50 HZ. System is provided for control circuits of contactors

modular of all 415 V switchgear or MCC space heating of various switchgears and

space heating of all motor above 37.5 KW rating. Each of modules with power

contactor.

415 V /24 V SYSTEMS: -24 V, 50 HZ. Supply is used for winding heating of motors

up to 37.5 KW. This is made available by one or more 1- 415 V/24 V, 4 KVA

transformers. Three transformers are provided with 415 V switchgear/MCB.

400 KV SYSTEMS: - Two 400 KV buses have been provided in switchyard and

are inter connected through a bus coupler. Each of the 2X600 MW generators are

connected to this system through a step up 150/200/250MVA generator.

220 V D.C. SYSTEMS: -

The station 220V D.C. system is used for control, interlocks, and

protection indication and annunciation circuit of various equipments. In addition some

critical unit and station auxiliary also operate on 220 V D.C. e.g. D.C. emergency oil

pump for turbine lubrication D.C. lightning etc.

CHAPTER-08,EFFICIENCY & CONCLUSION

97

8.1. EFFICIENCY

In KaTPP we convert potential energy or chemical energy of the fuel

into heat by the process of combustion. The heat is given to the water and it converts its

form into steam. The pressure of steam rotates the turbine, which is now in the form of

kinetic energy. Generator producing electrical energy, which is sand to different

localities for utilization, consumes this kinetic energy.

Enthalpy is defined as the thermodynamic property of a system, is equal

to the sum of its internal energy and the product of its pressure and volume.

Enthalpy is an ancient Greek word meaning evolution and many

eminent scholars have been attempted to define it. It is a mathematical concept of

available energy in the steam.

Efficiency in the case of electrical generator process can be expressed as

the amount of heat energy librated in the boiler compared with the amount of electrical

energy generated with it.

PLANT EFFICIENCY: -We will divide whole plant efficiency in four-component efficiency:

(1). Cycle efficiency

(2). Turbo generator efficiency

(3). Boiler efficiency

(4). Auxiliary power efficiency

Overall = Boiler x Turbine x Cycle x Generator

1. CYCLE EFFICIENCY: -

Cycle efficiency being the maximum possible heat energy that

could be obtained from any particular set of steam conditions employed. The operation

of heat reduction of condenser, which is almost 50% of the total available heat, makes

ranking cycle relatively inefficient.

It can be controlled by: -

(a). Condenser vacuum.

(b). Steam conditions of CV and LV

(c). Regenerative feed heating.

Cycle = energy available for conversion in work

Energy given in boiler as heat

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2. ALTERNATOR EFFICIENCY: - The alternator is a efficient machine at about 98

% efficiency. The losses are:

(a). Copper and iron loss

(b). Wind age losses

Operationally the plant is governed by the grid requirements. For voltage we use

the set out from generator transformer.

3. BOILER EFFICIENCY: - It depends upon:

(a). Dry flue gas loss: Increase by excess air in boiler.

(b). Wet flue gas loss: Moisture in coal.

(c). Moisture in combustion loss: Hydrogen loss.

(d). Radiator and in accounted loss.

4. TURBINE EFFICIENCY: -It means the efficiency of steam turbine in converting

the heat energy made available in the cycle into actual mechanical work.

Turbine losses falls into one or two groups either losses external to the turbine or losses

directly related to the expansion of the steam in the cylinder.

8.2 CONCLUSION

99

The first phase of Practical Training has proved to be quite fruitful. It

provides an opportunity for encounter with such huge machines like wagon tippler,

600MW Turbines and Generators.

The architecture of the power plant, the way various units are linked and

the way working of whole plant is controlled make the student realize that engineering

is not just learning the structure description and working of various machine but the

great part is of planning proper management.

It also provides an opportunity to lean low technology used at proper

place and time can cave a lot of labor.

But there are few factors that require special mention. Training is not

carried to its true spirit. It is recommended that there should be some project specially

meant for students where presence of authority should be ensured. There should be

strict monitoring of the performance of students and system of grading be improved on

basis of work done.

However training has proved to be quite fruitful. It has allowed an

opportunity to get an exposure of the practical implementation to theoretical

fundamentals.

REFERENCECHAPTER-09

100

[1].www.rrvunl.com

[2].www.energyindia.com

[3].www.googleindia.com

[4].www.thermalpower.com

[5].www.scibe.com

[6].Fundamentals of electrical engineering/power plant/tpp/655 ,Ashfaq Husain

Dhanpat Rai &Co.

[7].Generation of electrical power/thermal station, B R Gupta ,S.CHAND

PUBLICATION.

[8].EPC Book Volume-V,TCE 5248.A-H-500-001

[9].Annual Report o f TCE Ltd.

[10]. Single Line Diagram GID-118-EL-XJ-2012,BGR REPORT ON

KaTPP.

[11]. Single line diagram KaTPP Plan GID-2012,BGR ENERGY SYSTEM.

[12]. PPT On Thermal Plant/TCE/M Shreenivashan/104840/.

[13]. Assignment Shreenivashan /Tce /104840

http://www.rrvunl.com/

http://www.energyindia.com/

http://www.googleindia.com/

http://www.thermalpower.com/

http://www.scibe.com/

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