Summary

This paper reports an investigation on the phenomenon of refrigerant outgassing in the screw pump of a hermetic reciprocating compressor oil supply system. The interfacial mass transfer between the refrigerant and the lubricating oil is modelled by means of a cavitation model based on the Rayleigh-Plesset equation, considering a fixed mass fraction of refrigerant dissolved in the lubricant. The influence of compressor speed and compressor crankcase pressure is evaluated by comparing the oil volumetric flow rate and the oil volume fraction field for each simulation. The results reveal that significant outgassing of refrigerant may take place in the oil pump, which can lead to noise generation.

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