Air enters the ideal Brayton-Rankine combined cycle of Fig. 9.50 at 75°F and an atmospheric pressure of

Question:

Air enters the ideal Brayton-Rankine combined cycle of Fig. 9.50 at 75°F and an atmospheric pressure of 15 psia. The compressor pressure ratio is 6. Exhaust leaves the gas turbine at 2000°F and leaves the heat exchanger at 600°F. The mass flux of air through the Brayton cycle is 40 lbm/s. Steam leaves the Rankine side of the heat exchanger at 800 psia and 900°F and the steam turbine at 4 psia. Assuming constant specific heats for the air, calculate:
i) The net horsepower produced by the gas turbine
ii) The mass flux of the steam through the Rankine cycle
iii) The horsepower produced by the steam turbine
iv) The combined cycle efficiency
Figure 9.50