A reversed Brayton cycle, operating in a closed loop, uses nitrogen gas as the working fluid. The N 2 enters the compressor at 0°C and 120 kPa. The N 2 enters the turbine at 40°C and the compressor...

A reversed Brayton cycle, operating in a closed loop, uses nitrogen gas as the working fluid. The N₂
enters the compressor at 0°C and 120 kPa. The N₂
enters the turbine at 40°C and the compressor outlet pressure. The mass flow rate of the N₂
is 1.5 kg/s. The isentropic efficiencies of the compressor and turbine are both 0.80. Plot the rate at which heat is removed from the cold space through the cold heat exchanger and the coefficient of performance of the cycle as a refrigerator for compressor outlet pressures ranging between 400 kPa and 1500 kPa. Assume the nitrogen behaves as an ideal gas with constant specific heats.