Surface Tension of R290/Lubricant Oil Mixtures from 243 to 333 K

Abstract

Propane (R290) is a promising natural refrigerant with zero ODP and very low GWP. The surface tension of a refrigerant/oil mixture is of importance for its capillary flow rate, wettability, and heat transfer performance. In this study, the surface tension of R290 with three commercial lubricants 3GS, RL68H, and AB4 was measured in the temperature range from 243 to 333 K by the differential capillary rise method. The expanded uncertainty of the surface tension data was less than 0.32 mN m −1 (k = 2). The obtained surface tensions were correlated as a function of temperature and composition, and the average absolute deviations between the experimental and calculated results were 0.03 mN m −1 for R290/3GS, 0.06 mN m −1 for R290/RL68H, and 0.09 mN m −1 for R290/AB4 mixtures.