Comparisons of two-phase condensation and single-phase heat transfer and frictional pressure drop characteristics and energy-saving performance analysis of R-32 and R-410A in plate heat exchanger

Abstract

In this study, the heat transfer and frictional pressure drop characteristics of R-32 and R-410A in a plate heat exchanger are experimentally evaluated. The study comprises two-phase condensation, single-phase vapor, and liquid cooling experiments of R-32 and R-410A, as well as an independent single-phase water heat transfer experiment. The effects of heat flux, mass flux, condensing pressure, mean vapor quality, and refrigerant Reynolds number on heat transfer and pressure drop are assessed for comparisons of R32 and R410A. The results demonstrate that the heat transfer performance and frictional pressure drop increase with rising mass flux and mean vapor quality and decrease with declining condensing pressure in the two-phase condensation experiments. Furthermore, increasing the heat flux enhances the heat transfer performance while having negligible impact on the frictional pressure drop. In the single-phase cooling experiments, both heat transfer performance and frictional pressure drop rise with increasing refrigerant flow rate. Based on the experimental results, Nusselt number and friction factor correlations for two- and single-phase flows of R-32 and R-410A are developed and compared with the correlations from other studies. Finally, energy-saving performance is evaluated and compared between the refrigerants.