1. If the Carnot absorption refrigeration coefficient of performance of a new refrigeration unit is 4.20 and the environmental and generator temperatures are 70.0°F and 300.°F, respectively, determine the cooling (evaporator) temperature.
2. A new household refrigerator-freezer combination unit is designed with a dual-evaporator system. The freezer compartment is at -20.0°C and the refrigerator compartment is at 4.00°C.
The outlet of the condenser is at 28.0°C. The cooling capacities of both the refrigeration and the freezer compartments are to be 400. kJ/h each. The system uses refrigerant R-134a with a compressor isentropic efficiency of 87.0%. Determine
(a) the coefficient of performance for this design and
(b) the mass flow rate of refrigerant required.