A refrigeration unit is cooling a space to -5°C by rejecting energy to the atmosphere at 20°C. It is desired to reduce the temperature in the refrigerated space to a value of -25°C. Calculate (a) the coefficient of performance for the initial condition assuming a Carnot refrigerator, and (b) the minimum fractional increase in work required for the same amount of energy removed, (that is, find the ratio of the new work to the initial work).

A refrigeration unit is cooling a space to -5°C by rejecting energy to the atmosphere at 20°C. It is desired to reduce the temperature in the refrigerated space to a value of -25°C. Calculate (a) the coefficient of performance for the initial condition assuming a Carnot refrigerator, and (b) the minimum fractional increase in work required for the same amount of energy removed, (that is, find the ratio of the new work to the initial work).

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

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 12RQ: Refrigerators currently being manufactured in the United States are using______as their refrigerant.

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