Heat exchanger switchover in a refrigeration system: Thermodynamic modeling of a reversing valve

摘要

A mathematical model of a reversing valve was developed in order to evaluate the losses and for determining the effects of a reversing valve, on the performance of a heat pump. This mathematical model of the reversing valve was tested using the experimental data of Fang and Nutter (1999). The theoretical predictions made by this model agreed with that of the experimental data. Further, the mathematical model isolated the pressure losses due to friction; pipe-fittings, mass-leakage and heat transfer from the total losses. The evaluation of constituent losses assisted in detecting a faulty reversing valve, and also determining the effect of mass leakage and heat leakage on the compressor work input and COP of the heat pump.