Affiliation:
1. Poznan University of Technology, Faculty of Civil and Transport Engineering, Institute of Machines and Motor Vehicles
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.