A simple Brayton cycle uses Helium as the working fluid, has a maximum temperature of 1000 K, and a pressure ratio of 4. At the start of the compression, the Helium pressure and temperature are 50 kPa and 250 K. Based upon cold-air standard analysis assumptions, the thermal efficiency of the cycle is:
A. 0.13
B. 0.23
C. 0.43
D. 0.53
Answer:A
A simple Brayton cycle uses Helium as the working fluid, has a maximum temperature of 1000 K, and a pressure ratio of 4. At the start of the compression, the Helium pressure and temperature are 50 kPa and 250 K. Based upon cold-air standard analysis assumptions, the thermal efficiency of the cycle is:
A. 0.13 B. 0.23 C. 0.43 D. 0.53
Explanation: Using the pressure ratio = 1 – rp(1 – k) / k 5. A simple Brayton cycle has a pressure ratio of 5 and a maximum temperature of 900 K. Air enters the compressor at 100 kPa, 300 K. Based upon cold-air standard analysis assumptions, the back-work ratio of this cycle is: