Reversing valve heat transfer and pressure drops and their effects on the steady-state performance of a heat pump.

摘要

The effects of a reversing valve on the steady-state performance of a heat pump were analyzed. Three elements bring about a change in performance: heat transfer, pressure drops and mass leakage. The heat transfer and pressure drop effects are condsidered.; Experiments were conducted to measure the temperatures of a reversing valve and to provide the necessary data for calculating reversing valve heat loss. There calculations were done by a control-volume analysis and a surface heat-transfer analysis to determine the important paths of heat transfer. A heat-transfer model of the reversing valve was also developed.; Pressure drops in a reversing valve were measured and predicted in order to identify the important elements of pressure drops.; A heat pump model was developed to account for the presence of a reversing valve. The model was based on presently available heat pump models, and included the reversing valve in its thermodynamic cycle.; The effects of the reversing valve were examined using the heat pump model and the results of the heat-transfer and pressure drop studies. Of interest were the total and relative effects of those two losses plus a third type of loss, refrigerant leakage, which was the subject of a separate investigation. Effects of ambient conditions and heat pump operating mode were also considered.