A vapor-compression refrigeration system, using ammonia as the working fluid, has evaporator and condenser pressures of 1 bar and 14 bar, respectively. The refrigerant passes through the evaporator with a negligible pressure drop. At the inlet and exit of the compressor, the temperatures are -12oC and 210oC, respectively. The heat transfer rate from the working fluid passing through the condenser is 15 kW, and liquid exits the condenser at 12 bar, 28oC. If the compressor operates adiabatically, determine
(a) The compressor power input in kW and
(b) The coefficient of performance.