Condensation heat transfer characteristics of R245fa in a shell and plate heat exchanger for high-temperature heat pumps

摘要

In this study, the condensation heat transfer characteristics of R245fa in a shell and plate heat exchanger (SPHE) are measured and analyzed by varying the mean vapor quality from 0.16 to 0.86, mass flux from 16.0 to 45.0 kg M-2 S-1, heat flux from 1.3 to 9.0 kW M-2, and saturation temperature from 90 to 120 degrees C for high-temperature heat pumps (HTHPs). The condensation heat transfer coefficient and frictional pressure drop are shown to increase with increasing mean vapor quality and mass flux and with decreasing saturation temperature. The condensation heat transfer coefficient of R245fa in SPHE is on average 5.9% lower than that in the brazed plate heat exchanger (BPHE) with a similar effective heat transfer area. However, the average two-phase frictional pressure drop of R245fa in SPHE is 16.7% lower than that in BPHE. Empirical correlations for the condensation heat transfer coefficient and two-phase frictional pressure drop in SPHE are developed with mean absolute errors of 8.2% and 9.4%, respectively. (C) 2018 Elsevier Ltd. All rights reserved.