LUBRICATING PROPERTIES OF POLYESTER OILS AND R404A REFRIGERANT MIXTURES UNDER STARVED LUBRICATION CONDITIONS

Abstract

There has been a dynamic shift towards the use of ecological refrigerants in the refrigeration industry. Until recently, R404A was a quite commonly used HFC refrigerant for commercial refrigeration equipment, in both small and large systems resulting in the need to select appropriate compressor lubricants. In refrigeration compressors, the amount of oil in friction pairs in certain situations may be insufficient. In that event, starved lubrication conditions or lubrication only by refrigerant may occur. The article contains a methodical selection of test parameters for polyester oils allowing one to assess the lubricating properties of the mixtures of oils for refrigeration compressors and refrigerants under the conditions of poor lubrication. The article also includes the results of wear tests which allow one to evaluate the lubricating properties of oil-refrigerant mixtures under starved lubrication conditions for R404A refrigerant and polyester oils.