Refrigerant R12 is used in a vapour compression cycle. The saturated vapour enters the compressor at -18.8°C, and subsequently leaves at 75°C and 10 bar. The saturated liquid leaving the condenser is at 10 bar. The resulting stream is throttled and evaporated before being fed back to the compressor. a) Determine the coefficient of performance of the refrigerator. Take the specific enthalpy, h, at 10 bar and 36 K of superheat to be 163.7 kJ/kg b) Obtain the isentropic efficiency of the compressor. Take the specific entropy, s, at 10 bar to be 1.188 kJ/kg

Refrigerant R12 is used in a vapour compression cycle. The saturated vapour enters the compressor at -18.8°C, and subsequently leaves at 75°C and 10 bar. The saturated liquid leaving the condenser is at 10 bar. The resulting stream is throttled and evaporated before being fed back to the compressor. a) Determine the coefficient of performance of the refrigerator. Take the specific enthalpy, h, at 10 bar and 36 K of superheat to be 163.7 kJ/kg b) Obtain the isentropic efficiency of the compressor. Take the specific entropy, s, at 10 bar to be 1.188 kJ/kg

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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