The T-s diagram of a combined ideal Brayton-Rankine cycle is shown in Fig. 9.48. Air enters the isentropic compressor at 10°C and 100 kPa at state 5, with a mass flux of 8 kg/s. The pressure ratio for the compressor is 5. The combustor heats the air to 950 8 C. The air leaves the gas turbine and enters the "boiler" of an ideal Rankine cycle that operates between 10 kPa and 4 MPa. The air leaves the boiler at 325°C, and the steam leaves the boiler at 400°C. Assuming constant specific heats for the air, calculate:
i) The net power output of the ideal-gas turbine
ii) The efficiency of the ideal-gas turbine cycle
iii) The mass flux of the steam
iv) The power output of the ideal Rankine cycle
v) The efficiency of the ideal Rankine cycle
vi) The combined cycle efficiency
Figure 9.48

Transcribed Image Text:

Combustor 500 kPa 950 C GT Gas turbine Compressor 100 kPa Air 10 C 325 c Heat exchanger 100 kPa 400 C 4 MPa ST Steam turbine Pump 10 kPa Condenser out