Heat Transfer Coefficient, Low GWP, R513A, R134a, Condensation
There is increased interest in emerging, low global warming potential (GWP) refrigerants due to With tthe phase out of hydrofluorocarbon (HFC) refrigerants (e.g., R134a); and the need for lower global warming potential (GWP) replacements, there are many questions that still need to be answered about replacement refrigerants, including heat transfer performance. One promising alternative to R134a (GWP = 1300) is R513A (GWP = 573), which is a non-flammable mixture comprised of 44% R134a and 56% R1234yf by weight. While this low GWPR513A refrigerant is attractive due to its lower GWP and A1 flammability rating, heat transfer data are limited. Condensation experiments were conducted for R134a and R513A in a vapor compression loop using multiport (i.e., 9 parallel channels) extruded aluminum tubes; each channel’s hydraulic diameter was 0.72 mm. Experiments covered a range of average qualities (e.g., 0.2 < x < 0.8) and mass fluxes (e.g., 300 < G < 500 kg/m2s). Heat transfer coefficients and pressure drops are reported. The heat transfer coefficients of R513A were found to be very similar to R134a. Condensation data weare compared to the condensation heat transfer coefficient correlations developed by Shah (2009) and Kim and Mudawar (2013). The MAE of the Shah correlation for R513A was 22% and 6.5% for the Kim and Mudawar (2013) correlation for R513A.