A refrigeration cycle driven by an electric motor must maintain a computer laboratory at 180C when the outside temperature is 300C. The thermal load consists of heat transfers entering through the walls and roof of the laboratory at a rate of 75,000 kJ/h and from the computers, lighting, and occupants at a rate of 15,000 kJ/h. (a) Determine the minimum theoretical power required by the electric motor, in kW, and the corresponding coefficient of performance. (b) If the actual power required by the motor for this duty is 8.3 kW, determine the coefficient of performance. (c) If the given temperature and thermal load data are observed for a total of 100 hours and electricity costs 13 cents per kW*h, dtermine the cost, in $, over that period for each of case (a) and (b).

A refrigeration cycle driven by an electric motor must maintain a computer laboratory at 180C when the outside temperature is 300C. The thermal load consists of heat transfers entering through the walls and roof of the laboratory at a rate of 75,000 kJ/h and from the computers, lighting, and occupants at a rate of 15,000 kJ/h. (a) Determine the minimum theoretical power required by the electric motor, in kW, and the corresponding coefficient of performance. (b) If the actual power required by the motor for this duty is 8.3 kW, determine the coefficient of performance. (c) If the given temperature and thermal load data are observed for a total of 100 hours and electricity costs 13 cents per kW*h, dtermine the cost, in $, over that period for each of case (a) and (b).

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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