A vapor-compression refrigeration cycle employed in a heat pump uses refrigerant R-134a, and provides 15 kW of heating. The evaporator pressure is 2.8 bar, and the condenser pressure is 7 bar. Assume the refrigerant is a saturated vapor at the evaporator exit, and a saturated liquid at the condesner exit. The isentropic compressor efficiency is 80%. Determine the following:
I) the compressor work (kJ/kg)
II) the heating provided (kJ/kg)
III) the refrigerant flow rate (kg/s)
IV) the COP