Tribological analysis of hydrocarbon refrigerants applied to the hermetic compressor

This paper describes the tribological impacts of hydrocarbon refrigerants deployed in the domestic refrigerator hermetic compressor. In--use durability is examined from a tribological viewpoint. Experimental tribological information is presented from physical test procedures involving sliding tests to establish wear mechanisms and friction coefficients within critical components. Hydrocarbon refrigerant R600a is compared with hydroflourocarbon R134a using aluminium on steel samples within a novel pressurised micro--friction test rig. The refrigerant R600a is tested for its influence upon the tribological performance of mineral oil (MO) and poly--ol--ester (POE) lubricant, whilst an R134a/POE charge combination is used as a benchmark. Although wear rates were significantly greater for samples utilising POE lubricants than for MO, the friction coefficients were much lower.