The evaporator and condenser temperature of a 20 to-ton -capacity freezer are -28 OC and 23 OC respectively .The refrigerant 22 is subcooled by 3 OC before it enters the expansion valve and is superheated to 8 OC before leaving the evaporator .The compression is isentropic . A six cylinder single acting with stroke equal to bore running at 250 rpm is used . Neglect valve throttling and clearance effect Determine the refrigerating effect Calculate the theoretical piston displacement .Calculate the heat removed though the condenser Calculate the theoretical bore and stroke of the compressor

The evaporator and condenser temperature of a 20 to-ton -capacity freezer are -28 OC and 23 OC respectively .The refrigerant 22 is subcooled by 3 OC before it enters the expansion valve and is superheated to 8 OC before leaving the evaporator .The compression is isentropic . A six cylinder single acting with stroke equal to bore running at 250 rpm is used . Neglect valve throttling and clearance effect Determine the refrigerating effect Calculate the theoretical piston displacement .Calculate the heat removed though the condenser Calculate the theoretical bore and stroke of the compressor

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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A refrigerant 22 refrigeration carries a load of 82 kW at an evaporator pressure of 354 kPa and a condenser pressure of 1460 kPa. The liquid refrigerant is subcooled by 4 degrees before entering the expansion valve and the vapor is superheated by 5 degrees before entering the compressor. The stroke-to-bore ratio of the twin-cylinder compressor is 1.20 and the actual volumetric efficiency is 81 percent. Determine: a. The mass flowrate of the cooling water in the condenser for a 7-degree change in temperature, b. The bore and stroke
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