Small Heat Pump Air-conditioning Refrigerant R290 Lubricant Mixture Properties

Freon( CFCs, HCFCs) is widely used in the refrigerating equipments and air-conditioner. Because of their depleting the ozonosphere and making the earth become warmer, the developed countries had been prohibited from producing and used CFCs since 1996, and the banning schedule for HCFC-22 would be ahead from 2030 to 2020 according to the Montreal Revision. On the basis of analyzing the history, current situation and international and domestic tendency of alternative refrigerants, especial alternative for HCFCs, the paper demonstrate the possibility that propane (R290) substitute R22 in the small-sized heat pump, including the physical and chemical properties, theoretical refrigerating cycle, economic, safety concerning the R290, and etc,With the basic physical properties of approaching almost to R22's, stable chemical property, low price, compatibility with material used commonly in the refrigerating equipments, no damaging the environment, R290 has a bright future as alternative for R22.As a hydrocarbon, the flammability of R290 must be treated carefully. To safe operation of the refrigerating machine, under the premise of ensuring the COP of refrigerating system, the quantity of R290 charged should be minimized as its possibility. The solubility of propane with lubrication oil plays great influence on the quantity of refrigerants charged and the refrigerating effect of the system.To research the character of the mixtures of propane and lubricants, experimental installation is designed, experimental and testing method is optimized. The best refrigerating oil and the best ratio between refrigerant and lubricant are found through the comparative experiments of propane with commonly used compressor lubricants and analyzing the refrigerating performance under the corresponding condition. The experimental results indicate that insoluble propane and oil, which will result in the difficulty of returning oil of compressor, have little influence on the COP of refrigerating system. For soluble propane and oil, the quantity of lubrication oils charged should be limited below 5%(a maximum of no exceeding 20%). The PAG synthetic oil is the best choice for the refrigerating system, which takes propane as refrigerant, because it;can meet the requirements of safety, COP, returning oils of compressor, and etc, The suggestions that further complete and improve the application of propane are provided on the basis of summarizing the theoretical analysis and experimental research.Xiong Ailhg (Refrigeration and Cryogenic Engineering) Directed by Han Houde and Cao Hongfen...