An Experimental Investigation Of Evaporation Heat Transfer And Pressure Drop Of R290-Oil Mixtures In A Horizontal Micro-fin Tube

On the basis of the investigation on the related literatures of new refrigerants substitutes and new refrigerant oil, the in-tube evaporation of refrigerant and refrigerant-oil mixtures. This paper make a experimental research on the saturated temperature of propane (R290) and lubricant oil (Suniso 3GS) mixtures, evaporation heat transfer and pressure drop characteristics in a horizontal micro-fin tube. The experimental conditions are as follows: the oil concentration is 0.43﹪-5.28﹪, mass flux is 40-200, and the evaporation temperature is form -5℃ to +5℃, the vapor quality is from 0.1 to 0.18 at the inlet of the test section and 0.8-0.95 at the outlet of test section. We make a theoretical analysis of the experimental results and draw some conclusions as follows:① The saturated temperature R290-oil mixture is higher than that of pure R290 at a same pressure. The temperature difference, which is called superheat temperature of refrigerant-oil mixtures, increases as the oil concentration and the vapor quality are increased at a certain saturated pressure and pressure has negligible effect on the superheat temperature of the mixture. ( oil concentration is 0.43﹪-5.28﹪).② The investigation on the evaporation heat transfer characteristics in a horizontal micro-fin tube for R290-3GS mixture shows:a) The average evaporation heat transfer coefficient of the mixture increase with the increasing of the mass flux. b) The average evaporation heat transfer coefficient decreases with the increasing of the oil concentration.c) The evaporation temperature has negligible effect on the average evaporation heat transfer coefficient at the same oil concentration.③ A heat transfer correlation is concluded by comparing the experimental results with the past conference correlations. And the deviation between the predicted and experimental values is ±30﹪ .④ The experiment on the evaporation resistance characteristics of R290-3GS mixture shows the oil concentration has negligible effect on the drop of the mixture. ( oil concentration is 0.43﹪-5.28﹪)...