binary power cycles universitat rovira i virgili doctorate program in chemical and process...

Binary Power CyclesBinary Power Cycles

Universitat Rovira i VirgiliDoctorate Program in Chemical and Process Engineering

Department of Chemical and Mechanical Engineering

New Working Fluids For The Binary Power CyclesTuesday 3 of February 2005, Tarragona Spain.

Driss BAHJA2005 URV

New Working Fluids For The Binary Power CyclesTuesday 3 of February 2005, Tarragona Spain.

Driss BAHJA2005 URV


Contents:

Organic Rankine Cycles

Ammonia Power Cycles

New Working Fluid

Conclusion


The goal of our investigation is to improve the thermal efficiency of the power cycles by minimizing the entropy generated.

For this purpose we have investigated the using of the NH3-H2O as binary working fluid and other fluids for the Organic Rankine Cycle.

The irreversibilities depends on the types of the working fluids and heat sources. A cycle with lower irreversibility results in a better performance.


Organic Rankine CycleOrganic Rankine Cycle


Fluid MW Pc Tc Epsilon TypeIsobutane 58,12 36,4 407,8 -0,435 IsentropicIsopentane 72,15 33,7 460,4 1,073 Dry fluidn-Butane 58,12 37,96 425,1 -0,2702 Isentropicn-Hexane 86,17 30,58 507,9 1,969 Dry fluidn-Pentane 72,15 33,64 469,7 1,178 Dry fluidWater 18,02 220,6 647,1 -13,3 WetR11 137,4 44,08 471,2 -0,4506 IsentropicR12 120,9 41,14 385,2 -0,9609 DryR114 170,9 32,89 418,9 0,3804 IsentropicR123 152,9 36,68 456,8 0,1883 IsentropicR141b 117 42,49 477,4 -0,1952 IsentropicR152a 66,05 45,2 386,4 -2,492 Wet

Fluid MW Pc Tc Epsilon TypeIsobutane 58,12 36,4 407,8 -0,435 IsentropicIsopentane 72,15 33,7 460,4 1,073 Dry fluidn-Butane 58,12 37,96 425,1 -0,2702 Isentropicn-Hexane 86,17 30,58 507,9 1,969 Dry fluidn-Pentane 72,15 33,64 469,7 1,178 Dry fluidWater 18,02 220,6 647,1 -13,3 WetR11 137,4 44,08 471,2 -0,4506 IsentropicR12 120,9 41,14 385,2 -0,9609 DryR114 170,9 32,89 418,9 0,3804 IsentropicR123 152,9 36,68 456,8 0,1883 IsentropicR141b 117 42,49 477,4 -0,1952 IsentropicR152a 66,05 45,2 386,4 -2,492 Wet

Dry and Isentropic Working fluids are the more appropriate for the ORC


The selection of suitable organic fluids for use in (ORC) still deserves intensive thermodynamic and physical study of the working fluids.

The thermodynamic characteristics give rise to thermodynamic limitations to the amount of energy that can be extracted from the heat source.


Maximum and minimum pressure for ORC Pc Tc Pmax 120 ºC Pmin Bar 25ºCIsobutane 36,4 134,7 < 25 Bar 3,504Isopentane 33,7 187,2 < 10 Bar 0,9169n-Butane 37,96 152 < 20 Bar 2,437n-Hexane 30,58 234,7 < 5 Bar 0,2026n-Pentane 33,64 196,5 < 7 Bar 0,6892Water 220,6 374 < 3 Bar 0,03169R11 44,08 198 < 12 Bar 1,056R12 41,14 112 < 40 Bar 6,511R114 32,89 145,7 <20 Bar 2,132R123 36,68 183,7 < 12 0,9148R141b 42,49 204,2 < 10 Bar 0,7847R152a 45,2 113,3 < 40 Bar 5,972

Maximum and minimum pressure for ORC Pc Tc Pmax 120 ºC Pmin Bar 25ºCIsobutane 36,4 134,7 < 25 Bar 3,504Isopentane 33,7 187,2 < 10 Bar 0,9169n-Butane 37,96 152 < 20 Bar 2,437n-Hexane 30,58 234,7 < 5 Bar 0,2026n-Pentane 33,64 196,5 < 7 Bar 0,6892Water 220,6 374 < 3 Bar 0,03169R11 44,08 198 < 12 Bar 1,056R12 41,14 112 < 40 Bar 6,511R114 32,89 145,7 <20 Bar 2,132R123 36,68 183,7 < 12 0,9148R141b 42,49 204,2 < 10 Bar 0,7847R152a 45,2 113,3 < 40 Bar 5,972


Thermodynamic Performance

0

0,05

0,1

0,15

0 20 40 60

Pressure Bar

Cy

cle

Eff

icie

nc

y

R11

R12

R114

n-pentane

n-butane

Thermodynamic Performance

0

0,05

0,1

0,15

0 20 40 60

Pressure Bar

Cy

cle

Eff

icie

nc

y

R11

R12

R114

n-pentane

n-butane

Working fluids performanceWorking fluids performance


Optimization of the ORC n-pentane R11

η 0,1192 0,1496Q_Boiler 67768 65802 KWW_net 8080 9845 KWT_max 250 250 ºCT_min 38 38 ºCP_max 9,905 13,4 BarP_min 1,088 1,628 Bar

Optimization of the ORC n-pentane R11

η 0,1192 0,1496Q_Boiler 67768 65802 KWW_net 8080 9845 KWT_max 250 250 ºCT_min 38 38 ºCP_max 9,905 13,4 BarP_min 1,088 1,628 Bar


Fluid Formula ODP GWPR11 CCl3F 1 1R12 CCl2F2 1 3,05R114 CClF2CClF2 0,74 4,15R123 CHCl2CF3 0,02 0,02R141b CH3CCl2F 0,11 0,17R152a CH3CHF2 0 0,03

Fluid Formula ODP GWPR11 CCl3F 1 1R12 CCl2F2 1 3,05R114 CClF2CClF2 0,74 4,15R123 CHCl2CF3 0,02 0,02R141b CH3CCl2F 0,11 0,17R152a CH3CHF2 0 0,03


ORC Thermal effeciency

0

0,05

0,1

0,15

0 10 20 30

Pressure Bar

Th

erm

al E

ffic

ien

cy

n-Butane

n-pentane

ORC Thermal effeciency

0

0,05

0,1

0,15

0 10 20 30

Pressure Bar

Th

erm

al E

ffic

ien

cy

n-Butane

n-pentane

n-pentane n-butane thermal efficiencyn-pentane n-butane thermal efficiency


ORC Net Work

0

5000

10000

15000

0 10 20 30

Pressure Bar

Net

Wo

rk K

W

n-Butane

n-Pentane

ORC Net Work

0

5000

10000

15000

0 10 20 30

Pressure Bar

Net

Wo

rk K

W

n-Butane

n-Pentane

n-pentane n-butane Net Workn-pentane n-butane Net Work


0

100

200

300

400

500

600

700

0 0,5 1

EES Vapeur

EES Liquide

Aspen Vapeur

Apen liquid

REFPROPVapeur

REFPROP0

100

200

300

400

500

600

700

0 0,5 1

EES Vapeur

EES Liquide

Aspen Vapeur

Apen liquid

REFPROPVapeur

REFPROP

Comparison of different correlation of NH3-H2OComparison of different correlation of NH3-H2O


Variation of the enthalpy Ibrahim KleinVariation of the enthalpy Ibrahim Klein


0100200300400500600700800900

0 5000 10000

HRGV

Water

NH3-H2O

0100200300400500600700800900

0 5000 10000

HRGV

Water

NH3-H2O

Comparison of Water NH3-H2O HRGVComparison of Water NH3-H2O HRGV

NH3-H2O has better performance the temperature difference between the heat source and the working fluid is small.


NH3-H2O Rankine

00,020,040,06

0,080,1

0,12

0 50 100

Pressure Bar

Th

erm

al e

ffic

ien

cy

NH3-H2ORankine

NH3-H2O Rankine

00,020,040,06

0,080,1

0,12

0 50 100

Pressure Bar

Th

erm

al e

ffic

ien

cy

NH3-H2ORankine

Rankine using NH3-H2O thermal Rankine using NH3-H2O thermal efficiency variationefficiency variation


NH3-H2O Rankine

0

2000

4000

6000

8000

0 50 100

Pressure Bar

Net

Wo

rk

NH3-H2ORankine

NH3-H2O Rankine

0

2000

4000

6000

8000

0 50 100

Pressure Bar

Net

Wo

rk

NH3-H2ORankine

Rankine using NH3-H2O Net workRankine using NH3-H2O Net work


KSC34 Kalina CycleKSC34 Kalina Cycle


KCS 34

0

0,02

0,04

0,06

0,08

0,1

0,4 0,6 0,8 1

Basic fluid

Th

erm

al e

ffec

ien

cy

KCS 34

KCS 34

0

0,02

0,04

0,06

0,08

0,1

0,4 0,6 0,8 1

Basic fluid

Th

erm

al e

ffec

ien

cy

KCS 34

KCS 34 Thermal efficiency KCS 34 Thermal efficiency variation variation


KCS34

050

100150200250300350

0,4 0,6 0,8 1

Thermal effeciency

Net

Wo

rk

KCS34

KCS34

050

100150200250300350

0,4 0,6 0,8 1

Thermal effeciency

Net

Wo

rk

KCS34

Variation of thermal efficiency with Variation of thermal efficiency with the Net Work the Net Work


KCS11 Kalina CycleKCS11 Kalina Cycle


KCS11

0,11

0,115

0,12

0,125

0,13

0,135

20 30 40 50 60

Pressure

Th

erm

al e

ffec

ien

cy

KCS11

KCS11

0,11

0,115

0,12

0,125

0,13

0,135

20 30 40 50 60

Pressure

Th

erm

al e

ffec

ien

cy

KCS11

KCS11 thermal efficiency variation wKCS11 thermal efficiency variation w


KCS11

0

100

200

300

400

500

20 30 40 50 60

Pressure Bar

Net

Wo

rk K

wKCS11

0

100

200

300

400

500

20 30 40 50 60

Pressure Bar

Net

Wo

rk K

w

KCS11 Net Work VariationKCS11 Net Work Variation


Kalina Cycle as bottoming cycleKalina Cycle as bottoming cycle


Comparison between Rankine and Kalina Cycle as bottoming cycle

Maximum power Rankine at 40,98 BarMaximum power Rankine at 40,98 Bar


Comparison of thermal efficiencies:η = 0,3043 Rankine

η = 0,338 Kalina


New Working Fluid For the NH3-H2O Power cycle

We will review the VLE data with the objective to identify the new working fluid with wide boiling temperature range.

Working fluid will be eliminated if they will be toxic or flammable.

We will use the classical equation of states to calculate the thermodynamic properties.


Conclusion:

Our simulation of the ORC and the Kalina cycles have permit us to compare between the two power cycles.

The Ammonia-water has the advantage to boil at variable temperature which permit the fluid to match the heat source better than the steam for high pressure and temperature.

n-Butane have the better performance as working fluid in the ORC.


Successful development of an alternative to the ammonia-water Kalina cycle will provide new possibilities for improving the cycle efficiency.

Identification of a binary mixture, with a wide boiling range that can be adjusted to various temperature heat sources may allow its use not only as working fluid in the primary cycle, but also in bottoming cycles.

binary power cycles universitat rovira i virgili doctorate program in chemical and process...

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