Liquid refrigerant migration control by using an oil heater and its effects on mixture miscibility and viscosity

摘要

The solubility of fluorinated refrigerants in lubrication oil affects not only the stability performance of vapor compression refrigeration system, but also the safety control of start-up. It can cause oil foaming and reduction of viscosity,resulting in liquid slugging and improper lubrication. To void the deleterious effects, an oil heater is often used. But improper heater power can cause oil overheat. In this paper, the effects of heater power on miscibility and viscosity ofrefrigerant/oil mixture were calculated on basis of analyzing heat flow of a compressor and employing empirical correlation.