Research on condensation heat transfer characteristics of R447A, R1234ze, R134a and R32 in multi-port micro-channel tubes

R447A (R32/R1234ze/R125) is one of ternary mixture with GWP 572. In this paper, the condensation heat transfer characteristics of R447A (R32/R1234ze/R125) in 0.86 mm hydraulic diameter multi-port extruded (MPE) micro-tubes were investigated by experimental and theoretical analysis and compared the results with R134a, R32, R1234ze and their mixtures. The experiments were conducted under the mass fluxes ranged from 100 to 300 kg/m2 s, the vapor qualities from 0.05 to 0.96 and saturated temperatures from 35 to 45 °C. The results show that the heat transfer coefficient of R447A is lower than that of R32 greatly and R134a slightly, but higher than R1234ze. The performance of R447A is also better than the mixtures of R32/R134a (51%/49% and 24.5%/76.5% by mass), R32/R1234ze (45%/55% and 21%/79% by mass) and R410A. Silver-Bell-Ghaly (SBG) balance method was applied to revise the correlations, and the condensation heat transfer coefficients were predicted. On the basis of six revised correlations, the predicted mean absolute errors are within 30% compared with the experimental values.