Condensation Characteristics of Non-Azeotropic Mixture Refrigerant R32/R1234ze(E) inside Horizontal 4 mm Microfin Small-diameter Tubes

摘要

This study investigated the condensation heat transfer and frictional pressure drop of a refrigerant mixtureR32/R1234ze(E) inside three types of horizontal 4 mm outer diameter microfin tubes. We also evaluated thecondensation heat transfer and frictional pressure drop inside a horizontal smooth tube with similar outerdiameter. The experiment was carried out at a mass velocity range of 50 to 400 kgm~(-2)s~(-1), and at a pressurewhere the average of dew point and boiling point was 35 °C. The compositions of the R32/R1234ze(E) were20/80 and 50/50 mass%. The maximum temperature glide of the non-azeotropic mixture refrigerant ofR32/R1234ze(E) was 11 K. We evaluated the enhancement ratio of the heat transfer and the increment ratioof the pressure drop. In addition, we compared the experimental results with previous correlations toinvestigate the applicability for the non-azeotropic mixture in small-diameter microfin tubes.