Analyzing Thermodynamic CyclesThe refrigerator shown in Fig. P2.87 steadily receives a power input of 0.15 kW while...
Analyzing Thermodynamic Cycles
The refrigerator shown in Fig. P2.87 steadily receives a power input of 0.15 kW while rejecting energy by heat transfer to the surroundings at a rate of 0.6 kW. Determine the rate at which energy is removed by heat transfer from the refrigerated space, in kW, and the refrigerator’s coefficient of performance.
Fig. P2.87
Homework Answers
Write the energy balance for a refrigeration cycle,
Here, 
are net work input, net heat output and net heat input respectively.
Substitute 
In a refrigerator, this heat input is provided from the refrigerated space.
Hence, the energy removed by heat transfer from the refrigerated space is 0.45 kW
Coefficient of performance (COP) of a refrigerator,
Substitute 
Hence, the coefficient of performance for the refrigerator is 
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