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