Refrigerant 134a is the working fluid in a refrigeration cycle shown in the figure. The R134a enters the compressor at -35 °C, 0.6 bar, and leaves the condenser at 10 bar. 36 °C. The compressor has an isentropic efficiency of 80%. The mass flow rate of the refrigerant is 0.08 kg/s. The temperature at the outer surface of the condenser is 300 K. Air (ideal gas) enters the evaporator at 270 K, 1 atm and leaves the evaporator at 240 K, 1 atm. The expansion valve is a throttling valve. Ignore the stray heat from the compressor, determine (a) the compressor power, in kW, (b) the coefficient of performance, and (c) the rate of entropy production per cycle

Refrigerant 134a is the working fluid in a refrigeration cycle shown in the figure. The R134a enters the compressor at -35 °C, 0.6 bar, and leaves the condenser at 10 bar. 36 °C. The compressor has an isentropic efficiency of 80%. The mass flow rate of the refrigerant is 0.08 kg/s. The temperature at the outer surface of the condenser is 300 K. Air (ideal gas) enters the evaporator at 270 K, 1 atm and leaves the evaporator at 240 K, 1 atm. The expansion valve is a throttling valve. Ignore the stray heat from the compressor, determine (a) the compressor power, in kW, (b) the coefficient of performance, and (c) the rate of entropy production per cycle

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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