A two-stage compression refrigeration system with an adiabatic liquid- vapor separation unit uses refrigerant-134a as working fluid. The system operates the evaporator at -32°C, the condenser at 1.4 MPa, and the separator at 8.9°C. The refrigerant is circulated through the condenser at a rate of 2 kg/s. Given that the refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic;

A two-stage compression refrigeration system with an adiabatic liquid- vapor separation unit uses refrigerant-134a as working fluid. The system operates the evaporator at -32°C, the condenser at 1.4 MPa, and the separator at 8.9°C. The refrigerant is circulated through the condenser at a rate of 2 kg/s. Given that the refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic;

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

Chapter22: Condensers

Section: Chapter Questions

Problem 7RQ: When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be...

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Consider a two-stage compression refrigeration system operating between the pressure limits of 1.2 MPa and 0.16 MPa. The working fluid is refrigerant-134a. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.7 MPa. Part of the refrigerant evaporates and the remainder is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure, and it cools the refrigerated space as It vaporizes in the evaporator. Assume that the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic. a) i) Determine the amount of heat removed from the refrigerated space ii) Determine the compressor work per unit mass of refrigerant flowing through the condenser b) Determine the coefficient of performance