Experimental Determination of Forced Convection Evaporative Heat Transfer Coefficients for Non-Azeotropic Refrigerant Mixtures

摘要

A number of experiments were conducted in the 1960's to determine the two phase heat transfer coefficient, h TP of pure refrigerants. Recently energy conservation requirements spurred interest in nonazeotropic refrigerant mixtures, because such mixtures can improve theoretically the COP of certain refrigerant cycles. The two phase heat transfer coefficient of such mixtures under forced convection conditions virtually unknown. An experimental rig has been constructed to investigate whether it is possible to predict the heat transfer coefficient of the mixture based on the coefficients of the components. Initially data was taken on R-22 and compared to literature data and to existing predictive correlations. Good agreement was found with the literature's data on forced convection, single phase heat transfer correlations, and some two phase evaporative correlations. Single phase heating and two phase boiling experiments were conducted then on RlS2a and R13Bl individually and in various mixture concentrations. The results of these tests reported in the paper.