trabajo de turbomaquinas

TRABAJO DE TURBOMAQUINAS

1.- Considere una central térmica para generación eléctrica con una potencia neta de 100 MW, que opera bajo un ciclo Brayton (turbina de gas), tiene una relación de presiones de 10. El aire ingresa al compresor a 25 C y 98 kPa, mientras que a la turbina lo hace a 1200 K. Desarrolle una solución que indique el efecto de la temperatura de ingreso a la turbina sobre trabajo neto, calor añadido, rendimiento térmico y el flujo de masa de aire. Grafique los resultados.

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SESSION NUMBER = 1

10:00 11:38 06-07-2009

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BRAYTON POWER CYCLE ANALYSIS

Process Process Description

1-2: Adiabatic compression

2-3: Constant pressure heat addition

3-4: Adiabatic expansion

4-1: Constant pressure heat rejection

Working Fluid: Air

Constant specific heat at 300 K is assumed

Compressor adiabatic efficiency: 100.0 0%

Turbine adiabatic efficiency: 100.00%

Compressor inlet pressure, P1: 0.098 MPa

Compressor inlet temperature, T1: 25.00 C

Cycle compression ratio, P2/P1: 10.0 0

T3 T2 P2 Qin T4 Wc Wt Wnet Wc/Wt EFF°C °C MPa kJ/kg °C kJ/kg kJ/kg kJ/kg % %

926.85 302.4 1 627.4 348.5 278.7 581.2 302.4 47.96 48.2900 302.4 1 600.4 334.5 278.7 568.1 289.4 49.06 48.2880 302.4 1 580.3 324.2 278.7 558.5 279.7 49.91 48.2850 302.4 1 550.2 308.6 278.7 543.9 265.2 51.25 48.2820 302.4 1 520 293.1 278.7 529.4 250.7 52.65 48.2800 302.4 1 499.9 282.7 278.7 519.7 241 53.63 48.2780 302.4 1 479.8 272.4 278.7 510 231.3 54.65 48.2750 302.4 1 449.7 256.8 278.7 495.5 216.8 56.26 48.2700 302.4 1 399.5 230.9 278.7 471.3 192.5 59.15 48.2670 302.4 1 369.3 215.4 278.7 456.8 178 61.03 48.2

T3 Wnet Qin EFFFlujo de Masa

de AirePotencia

C kJ/kg kJ/kg % kg/s MW926.85 302.4 627.4 48.2 0.330687831 100

900 289.4 600.4 48.2 0.345542502880 279.7 580.3 48.2 0.357525921850 265.2 550.2 48.2 0.377073906820 250.7 520 48.2 0.398883127800 241 499.9 48.2 0.414937759780 231.3 479.8 48.2 0.432338954750 216.8 449.7 48.2 0.461254613700 192.5 399.5 48.2 0.519480519670 178 369.3 48.2 0.561797753

650 700 750 800 850 900 9500

100

200

300

400

500

600

700

Efecto de la Temperatura de Ingreso a la Turbina

Wnet [kJ/kg]Qin [kJ/kg]EFF [%]Flujo de Masa de Aire [kg/s]

T3

Wne

t, Q

in, E

FF, M

asa

2.- Una central eléctrica opera en un ciclo Rankine con Regeneración. El vapor ingresa a la turbina a 15 MPa y 60 C, con un flujo de masa de 7.7 kg/s, mientras que el condensador lo hace a 10 kPa. La eficiencia isentrópica de la turbina es de 80 % y de las bombas 95 %. El vapor se extrae de la turbina a 0.5 MPa para calentar el agua de alimentación en un calentador abierto. El agua sale del calentador como líquido saturado. Desarrolle una solución que indique el efecto de la presión de extracción (cambiando 5 valores) sobre el trabajo neto, calor añadido y rendimiento térmico. Grafique los resultados. Para la mejor solución determine la potencia neta de la central.

Con Variación de Presión de Extracción con un delta de 100

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SESSION NUMBER = 1

07:32:14 06-07-2009

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REGENERATIVE STEAM POWER CYCLE ANALYSIS

FOR AN OPEN FEEDWATER HEATER BY CENGEL/BOLES


1-2: Adiabatic pumping to feedwater heater pressure

2-3: Constant pressure feedwater heating

3-4: Adiabatic pumping to boiler pressure

4-5: Constant pressure heat addition in boiler

5-6: Adiabatic expansion in turbine

6-3: Constant pressure cooling of extracted steam


7-1: Constant pressure heat rejection in condenser

T5 (Turbine inlet temperature) = 600.00 C Pump Efficiency = 95.00 %

P5 (Turbine inlet pressure) = 15000.00 kPa Turbine Efficiency = 80.00 %

P7 (Condenser pressure) = 10.00 kPa

P5 is the extraction pressure for the feedwater heater.

m6/m5 is the fraction of mass extracted from the turbine for

the feedwater heater.

P6 m6/m5 Qin Qout Wturb Wpump1 Wpump2 EFFICIENCYkPa kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg %500 0.1675 2925.39 1845.34 1097.17 0.43 16.68 36.92600 0.177 2895.05 1824.21 1088.05 0.52 16.69 36.99700 0.1853 2868.4 1805.93 1079.75 0.6 16.68 37.04800 0.1925 2844.52 1789.78 1072.09 0.68 16.67 37.08900 0.1991 2822.83 1775.16 1065.06 0.76 16.64 37.11

1000 0.205 2802.88 1762.12 1058.21 0.84 16.61 37.131100 0.2105 2784.38 1750.05 1051.83 0.91 16.58 37.151200 0.2154 2767.1 1739.07 1045.57 0.99 16.55 37.151300 0.2201 2750.87 1728.61 1039.83 1.07 16.5 37.161400 0.2245 2735.55 1718.96 1034.19 1.15 16.45 37.16

Enthalpy Summary:P6 H1 H2 H3 H4 H5 H6 H7kPa kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg500 191.83 192.35 640.23 656.91 3582.3 2866.56 2408.4600 191.83 192.46 670.56 687.25 3582.3 2893.42 2408.4700 191.83 192.56 697.22 713.9 3582.3 2916.6 2408.4800 191.83 192.67 721.11 737.78 3582.3 2937.17 2408.4900 191.83 192.78 742.83 759.47 3582.3 2954.94 2408.4

1000 191.83 192.88 762.81 779.42 3582.3 2972.7 2408.41100 191.83 192.99 781.34 797.92 3582.3 2988.4 2408.41200 191.83 193.1 798.65 815.2 3582.3 3004.09 2408.41300 191.83 193.2 814.93 831.43 3582.3 3017.42 2408.41400 191.83 193.31 830.3 846.75 3582.3 3030.74 2408.4

P6 Wnet Qin EFFICIENCY Flujo de Masa[kPa] [kJ/kg] [kJ/kg] [%] [kg/s]

1400 1016.53038 2735.55 37.16 7.71300 1022.22329 2750.87 37.16 1200 1027.97765 2767.1 37.15 1100 1034.39717 2784.38 37.15 1000 1040.70934 2802.88 37.13

900 1047.55221 2822.83 37.11 800 1054.74802 2844.52 37.08 700 1062.45536 2868.4 37.04 600 1070.879 2895.05 36.99 500 1080.05399 2925.39 36.92

400 600 800 1000 1200 1400 16000

500

1000

1500

2000

2500

3000

3500

Efecto de la Presión de Extracción

Wnet [kJ/kg]Qin [kJ/kg]EFFICIENCY [%]

P5

Wne

t, Q

in, E

FF

P5 Wnet Qin EFFICIENCY Flujo de Masa Potencia Neta[kPa] [kJ/kg] [kJ/kg] [%] [kg/s] [MW]1400 1016.53038 2735.55 37.16 7.7 7.8272839261300 1022.22329 2750.87 37.16 7.8711193481200 1027.97765 2767.1 37.15 7.9154279051100 1034.39717 2784.38 37.15 7.9648582091000 1040.70934 2802.88 37.13 8.013461949900 1047.55221 2822.83 37.11 8.06615204800 1054.74802 2844.52 37.08 8.121559723700 1062.45536 2868.4 37.04 8.180906272600 1070.879 2895.05 36.99 8.245768262500 1080.05399 2925.39 36.92 8.316415708

Con Variación de Presión de Extracción con un delta de aproximado al real

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SESSION NUMBER = 1

11:04:34 06/07/20029

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REGENERATIVE STEAM POWER CYCLE ANALYS IS

FOR AN OPEN FEEDWATER HEATER BY CENGEL/BOLES

ProcessProcess Description

1-2: Adiabatic pumping to feedwater heater pressure

2-3: Constant pressure feedwater heating


4-5: Constant pressure he at addition in boiler




7-1: Constant pressure he at rejection in condenser

T5 (Turbine inlet temperature ) = 600.00 C Pump Efficiency = 95.00%

P5 (Turbine inlet pressure) 1500000 kPa Turbine Efficiency = 80.00%

P7 (Condenser pressure) 1000 kPa

P5 is the extraction pressure for the feedwater heater.

m6/m5 is the fraction of mass extracted from the turbine for the feedwater heater.

P5 m6/m5 Qin Qout Wturb Wpump1 Wpump2 EFFICIENCYkPa kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg %500 0.1675 2925.39 1845.34 1097.17 0.43 16.68 36.92270 0.1368 3019.53 1913.3 1123.05 0.24 16.58 36.64102 0.0925 3146.19 2011.63 1151.02 0.09 16.37 36.0634 0.0467 3264.99 2112.97 1168.18 0.02 16.13 35.28

400 0.1561 2960.9 1870.54 1107.37 0.35 16.66 36.83150 0.1095 3098.73 1973.75 1141.58 0.13 16.46 36.370 0.0764 3189.33 2047.27 1158.39 0.06 16.28 35.81

450 0.1621 2942.39 1857.32 1102.12 0.39 16.66 36.88200 0.1227 3061.07 1944.6 1133.17 0.18 16.53 36.47

Enthalpy Summary:P6 H1 H2 H3 H4 H5 H6 H7kPa kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg kJ/kg500 191.83 192.35 640.23 656.91 3582.3 2866.56 2408.4270 191.83 192.11 546.19 562.77 3582.3 2780.03 2408.4102 191.83 191.93 419.73 436.11 3582.3 2655.83 2408.434 191.83 191.86 301.17 317.31 3582.3 2530.9 2408.4

400 191.83 192.24 604.74 621.4 3582.3 2834.55 2408.4150 191.83 191.98 467.11 483.57 3582.3 2703.46 2408.470 191.83 191.89 376.69 392.97 3582.3 2611.43 2408.4

450 191.83 192.3 623.25 639.91 3582.3 2851.31 2408.4200 191.83 192.03 504.7 521.23 3582.3 2740.34 2408.4

P6 Wnet Qin EFFICIENCY Flujo de Masa

[kPa] [kJ/kg] [kJ/kg] [%] [kg/s]

500 1080.05399 2925.39 36.92 7.7

450 1085.15343 2942.39 36.88

400 1090.49947 2960.9 36.83

270 1106.35579 3019.53 36.64

200 1116.37223 3061.07 36.47

150 1124.83899 3098.73 36.3

102 1134.51611 3146.19 36.06

70 1142.09907 3189.33 35.81

34 1151.88847 3264.99 35.28

0 100 200 300 400 500 6000

500

1000

1500

2000

2500

3000

3500

Efecto de la Presión de Extracción

Wnet [kJ/kg]Qin [kJ/kg]EFFICIENCY [%]

P5

Wne

t, Q

in, E

F

P6 Wnet Qin EFFICIENCY Flujo de Masa Potencia Neta[kPa] [kJ/kg] [kJ/kg] [%] [kg/s] [MW]

500 1080.05399 2925.39 36.92 7.7 8.316415708450 1085.15343 2942.39 36.88 8.355681426400 1090.49947 2960.9 36.83 8.396845919270 1106.35579 3019.53 36.64 8.518939598200 1116.37223 3061.07 36.47 8.596066163150 1124.83899 3098.73 36.3 8.661260223102 1134.51611 3146.19 36.06 8.735774078

70 1142.09907 3189.33 35.81 8.79416286234 1151.88847 3264.99 35.28 8.869541234

3.- Una central eléctrica a vapor opera con un ciclo Rankine con recalentamiento intermedio y regeneración a través de 4 calentadores de agua: 3 de superficie y 1 de contacto. El vapor ingresa a la turbina de presión alta a 15 MPa y 600 C, mientras que la turbina de presión baja a 1 MPa y 500 C. La presión en el condensador es de 10 KPa. Cambiando un set de cuatro valores determine el mejor rendimiento térmico. Para el mejor valor de rendimiento térmico, calcule el flujo de masa de vapor que fluye a través del generador de vapor (caldera) si la central debe producir una potencia neta de 120 MW.

PRIMER SET

VALORES INGRESADOS

P11 (HP CFWH pressure) = 300.00 kPa

P12 (IP CFWH pressure) = 162.00 kPa

P13 (OFWH pressure) = 62.00 kPa

P14 (LP CFWH pressure) = 20.00 kPa

REHEAT-REGENERATIVE POWER CYCLE ANALYSIS

" THREE CLOSED, ONE OPEN FEEDWATER HEATERS BY CENGEL/BOLES"


1-2: Adiabatic pumping to open feedwater heater pressure

2-3: Constant pressure closed feedwater heating

3-4: Constant pressure open feedwater heating





8-9: Adiabatic expansion in high pressure turbine

9-10: Constant pressure reheating in boiler







16-17: Throttling from HP CLOSED FWH to IP CLOSED FWH

18-19: Throttling from IP CLOSED FWH to OPEN FWH

16-17: Throttling from LP CLOSED FWH to condenser

T8 (Turbine inlet temp.) = 600.00 C Pump Efficiencies = 100.00 %

P8 (Turbine inlet press.) = 15000.00 kPa Turbine Efficiency = 100.00 %

P15 (Condenser pressure) = 10.00 kPa HP CFWH: m11/m8 = 0.0333

P10 (Reheat pressure) = 1000.00 kPa IP CFWH: m12/m8 = 0.0386

T10 (Reheat temperature) = 500.00 C OFWH: m13/m8 = 0.0384

P11 (HP CFWH pressure) = 300.00 kPa LP CFWH: m14/m8 = 0.0229

P12 (IP CFWH pressure) = 162.00 kPa Quality 15 = 94.83 %

P13 (OFWH pressure) = 62.00 kPa Cond. Qout 15-1 = 1968.05 kJ/kg

P14 (LP CFWH pressure) = 20.00 kPa Cycle efficiency = 46.51 %

Work and heat transfer are calculated per unit mass flow to turbine at state 8

Turbines: Wout 8-9 = 762.00 Wout 10-15 = 964.47 Wout total = 1726.47 kJ/kg

Pumps: Win 1-2 = 0.05 Win 4-5 = 15.44 Win total = 15.49 kJ/kg

Boiler: Qin 7-8 = 3020.83 Qin 9-10 = 658.20 Qin total = 3679.03 kJ/kg

State h kJ/kg State h kJ/kg State h kJ/kg State h kJ/kg State h kJ/kg1 191.83 5 378.7 9 2820.3 13 2741.43 16,17 561.472 191.88 6 476.65 10 3478.5 14 2560.94 18,19 476.653 251.4 7 561.47 11 3106.61 15 2460.92 20,21 251.44 363.26 8 3582.3 12 2940.57

SEGUNDO SET

VALORES INGRESADOS






THREE CLOSED, ONE OPEN FEEDWATER HEATERS BY CENGEL/BOLES

































State h kJ/kg State h kJ/kg State h kJ/kg State h kJ/kg State h kJ/kg1 191.83 5 435.29 9 2820.3 13 2846.17 16,17 640.232 191.92 6 546.19 10 3478.5 14 2626.29 18,19 546.193 301.17 7 640.23 11 3251.44 15 2460.92 20,21 301.17

4 419.73 8 3582.3 12 3074.74

TERCER SET

VALORES INGRESADOS




















4 478.24 8 3582.3 12 3208.75

CUARTO SET

VALORES INGRESADOS




















4 494.07 8 3582.3 12 3242.65

Mejor rendimiento térmico es con los datos ingresados en el cuarto set con

Cycle efficiency = 47.16 %

Para este set con el mejor rendimiento térmico tenemos:

Wnet Potencia NetaFlujo de Masa

de VaporkJ/kg kW kg/s

1649.50117 120000 72.74926629

trabajo de turbomaquinas

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desarrolle

grafique los

el vapor ingresa

unit mass

constant pressure

constant pressure

hp cfwh pressure

flujo de masa