A vapor-compression refrigeration system, using ammonia as the working fluid, has evaporator and condenser pressures of 30 and 200 lbf/in.2, respectively. The refrigerant passes through each heat exchanger with a negligible pressure drop. At the inlet and exit of the compressor, the temperatures are 108F and 3008F, respectively. The heat transfer rate from the working fluid passing through the condenser is 50,000 Btu/h, and liquid exits at 200 lbf/in.2, 908F. If the compressor operates adiabatically, determine
(a) the compressor power input, in hp.
(b) the coefficient of performance.