Air enters the compressor of an ideal Brayton refrigeration cycle at 120 kPa and 275 K. The

Question:

Air enters the compressor of an ideal Brayton refrigeration cycle at 120 kPa and 275 K. The compressor pressure ratio is 3, and the temperature at the turbine inlet is 325 K. Treating air as a perfect gas, determine
(a) The refrigeration capacity per unit mass of air flow, in kJ/kg and
(b) The net work input per unit mass of air flow (wnet), in kJ/kg,
(c) The coefficient of performance (COPR).