Vapor Compression Refrigeration System A refrigerating machine using R-12 as refrigerant operates between the pressures 2.5 bar and 9.0 bar. The compression is isentropic and there is not under cooling in the condenser. The vapour is dry and saturated condition at the beginning of the compression. Estimate the theoretical COP. If the actual COP is 0.65 of theoretical COP, calculate the net cooling produced per hour. The refrigerant flow is 5 Kg/min. The properties of refrigerant are : Pressure Satu. temp. (Bar) 9.0 Enthalpy (kJ/kg) Liquid 70.55 Entropy (kJ/kg K) Vapour (°C) Vapour 36 201.8 0.6836 2.5 -7 29.62 Take specific heat of superheated vapour at 9 bar as 0.64 kJ/kg K. 184.5 0.7001 Compressor pressure = 9 bar Evaporator pressure = 2.5 bar COND COND 2' 36°C 36°C COMP EVAPO EVAPO -7°C -7°C h4 Professor Dr. Mohammad Zoynal ABEDIN Dept. of ME, DUET, Gazipur MCE 4391 Department of EEE IUT, Board Bazar, Gazipur Basic Mechanical Engineering EXPN COMP 2.

Vapor Compression Refrigeration System A refrigerating machine using R-12 as refrigerant operates between the pressures 2.5 bar and 9.0 bar. The compression is isentropic and there is not under cooling in the condenser. The vapour is dry and saturated condition at the beginning of the compression. Estimate the theoretical COP. If the actual COP is 0.65 of theoretical COP, calculate the net cooling produced per hour. The refrigerant flow is 5 Kg/min. The properties of refrigerant are : Pressure Satu. temp. (Bar) 9.0 Enthalpy (kJ/kg) Liquid 70.55 Entropy (kJ/kg K) Vapour (°C) Vapour 36 201.8 0.6836 2.5 -7 29.62 Take specific heat of superheated vapour at 9 bar as 0.64 kJ/kg K. 184.5 0.7001 Compressor pressure = 9 bar Evaporator pressure = 2.5 bar COND COND 2' 36°C 36°C COMP EVAPO EVAPO -7°C -7°C h4 Professor Dr. Mohammad Zoynal ABEDIN Dept. of ME, DUET, Gazipur MCE 4391 Department of EEE IUT, Board Bazar, Gazipur Basic Mechanical Engineering EXPN COMP 2.

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

Chapter47: High-pressure, Low-pressure, And Absorption Chilled-water Systems

Section: Chapter Questions

Problem 13RQ: The subcooling temperature in a condenser can be measured by taking the difference between the A....

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