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An ideal vapor-compression refrigeration cycle uses R-134a

An ideal vapor-compression refrigeration cycle uses R-134a as the working fluid in an air-conditioning system. The refrigerant enters the compressor as a saturated vapor at 40 °F and leaves the condenser as a saturated liquid at 130 °F. The mass flow rate of the refrigerant is 1.5 lbm/s. Calculate the following:
a. The heat transfer rate in the condenser
b. The heat transfer rate in the evaporator

Solution Preview

Please see the attached file.

First look up the thermodynamic data in the reference:
Saturated vapor at 40oF, hg = 107.39 (Btu/lbm), sg = 0.2189 (Btu/lbmR)
Saturated liquid at 130°F, hf = 55.3 (Btu/lbm), P = 215 psia.
For an ideal cycle, across the expansion valve, there's no change in enthalpy, so ...

Solution Summary

The solution provides diagram, explanations, calculations and discussion for the refrigeration problem.

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