Study of Pressure Drop of Refrigerant Mixtures Inside Enhanced Surface Tubing

Abstract

Two phase flow pressure drop characteristics observed during condensation and boiling of azeotropic refrigerant mixtures R-404A (R125/R134a/R143a:44/4/52), R-407B (R32/R125/ R134a:10/70/20), R407C (R32/R125/R134a:23/25/52) and R408A (R22/R125/R143a:46/7/47) are presented in this paper. Experiments showed that for liquid Reynolds numbers higher than 3.00 E06, R-408A appears to have greater heat transfer rates than the other blends under investigation. Furthermore, it is quite evident from this data that R-407C has the highest specific pressure drop among the refrigerants under investigation.