A vapor-compression refrigeration system operates on the cycle of Fig. 9.1. The refrigerant is tetrafluomethane (Table 9.1. Fig, G.2). For one of the following sets of operating conditions, determine the circulation rate of the refrigerant, the heat-transfer rate in the condenser, the power requirement, the coefficient of performance of the cycle, and the coefficient of performance of a Carnot refrigeration cycle operating between the same temperature levels.
(a) Evaporation t = 30(°F); condensation t = 80(°F); η(compressor) = 0.79; refrigeration rate = 600(Blu)(s)-1.
(b) Evaporation t = 2CH°F); condensation t = 80(°F); η(compressor) = 0.78; refrigeration rate = 500(Btu) (s)-1.
(c) Evaporation t = 10(°F); condensation t = 80(°F); η(compressor) = 0.77: refrigeration rate = 400(Blu)(s)-1.
(d) Evaporation t = 0(°F); condensation t = 80(°F); η(compressor = 0.76; refrigeralion rate - 300(Btu) (s)-1.
(e) Evaporation t = - 10(°F); condensation r = 80(°F); η(compressor) = 0.75; refrigeration rate = 200(Btu)(s)-1.