Two domestic refrigerators X and Y are under consideration. During every cycle each refrigerator removes QC=150kJ of heat from the food compartment at TC=275K and rejects heat to the kitchen air at TH=305K. However, their required work inputs differ:
Refrigerator X : W=30kJ per cycle
Refrigerator Y : W=22kJ per cycle
a) Calculate the coefficient of performance (COP) of each refrigerator.
b) Determine the maximum possible COP for a reversible refrigerator working between the given temperatures.
c) Using your answers, state which refrigerator is more energy-efficient and quantify how much closer it is to the ideal value than the other model.