3294 (RP-378) -- Experimental Study on Condensation of Refrigerant-Oil Mixtures, Part III: R-12 and R-22 on the External Surface of Single and Multiple Horizontal Finned Tubes

This is the third part of the "Experimental Study on Condensation of Refrigerant-Oil Mixtures." Presented here are the test results of R-12 and R-22 on the external surface of horizontal finned tubes. The off used in this study is alkylbenzene-based. Both pure refrigerant vapor tests and vapor-oil mixture tests were conducted at two different condensing temperatures--32.2° and 40.5°C (90 ° and 105°F), respectively. It was found that the presence of oil in R-12 and R-22 vapor with any mass ratio lowers the condensing coefficient. However, the reduction of the condensing coefficient is not proportional to the percent of oil in the refrigerant vapors for the finned tubes. As for the pressure drop across the condenser, the effect of oil in the refrigerant vapors is not noticeable.