Refrigerant vapor enters into the compressor of a standard vapor compression cycle at -10°C (h = 402 kJ/kg) and leaves the compressor at 50°C (h = 432 kJ/kg). It leaves the condenser at 30°C (h = 237 kJ/kg). The COP of the cycle is_______

Refrigerant vapor enters into the compressor of a standard vapor compression cycle at -10°C (h = 402 kJ/kg) and leaves the compressor at 50°C (h = 432 kJ/kg). It leaves the condenser at 30°C (h = 237 kJ/kg). The COP of the cycle is_______

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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When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be higher in temperature than the entering air temperature.
Refrigerant vapor enters into the compressor of a standard vapor compression cycle at - 10°C (h = 402 kJ/kg) and leaves the compressor at 50°C (h = 432 kJ/kg). It leaves the condenser at 30°C (h = 237 kJ/kg). Calculate the COP of the cycle.
Problem 1 (Using thermodynamic tables)A large refrigeration plant is to be maintained at -12 C. It requires refrigeration at a rate of 120 kW.The condenser of the plant is to be cooled by liquid water, which experiences a temperature rise of 10 C as it flows over the coils of the condenser. Assuming the plant operates on the ideal vapor-compression cycle using refrigerant- 134a between the pressure limits of 100 and 700 kPa, determine (a) the mass flow rate of the refrigerant, (b) the power input to the compressor, and (c) the mass flow rate of the cooling water
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