Refrigerant 134a is the working fluid in a vapor-compression heat pump system with a heating capacity of 24,000 Btu/h. The condenser operates at 160 lbf/in2, and the evaporator temperature is -10F. The refrigerant is a saturated vapor at the evaporator exit and a liquid at 105F at the condenser exit. Pressure drops in the flows through the evaporator and condenser are negligible. The compression process is adiabatic, and temperature at the compressor exit is 140F. Determine:
The mass flow rate of refrigerant, in lbm/min
The power input to the compressor in horsepower
The coefficient of performance
The isentropic compressor efficiency