An air conditioner with refrigerant-134a as the working

Chapter 11, Problem 111P

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11-111 An air conditioner with refrigerant-134a as the working fluid is used to keep a room at \(26^{\circ} \mathrm{C}\) by rejecting the waste heat to the outside air at \(34^{\circ} \mathrm{C}\). The room is gaining heat through the walls and the windows at a rate of \(250 \mathrm{~kJ} / \mathrm{min}\) while the heat generated by the computer, TV, and lights amounts to . An unknown amount of heat is also generated by the people in the room. The condenser and evaporator pressures are 1200 and , respectively. The refrigerant is saturated liquid at the condenser exit and saturated vapor at the compressor inlet. If the refrigerant enters the compressor at a rate of  and the isentropic efficiency of the compressor is 75 percent, determine    

(a) the temperature of the refrigerant at the compressor exit,

(b) the rate of heat generation by the people in the room.

(c) the COP of the air conditioner, and

 the minimum volume flow rate of the refrigerant at the compressor inlet for the same compressor inlet and exit conditions.

Equation Transcription:

     

     

kJ/min

Text Transcription:

26°C    

34°C      

250kJ/min