In this study, solubility data are used to explain temperature measurements obtained for a refrigerant/lubricant mixture at the inlet and exit of an evaporator and condenser. The significance of these solubility effects on determining two-phase heat transfer coeffcients for refrigerant/lubricant mixtures is also discussed. As part of this study, solubility data are presented for HFC-134a (R134a) and a 169 SUS and 369 SUS penta erythritol ester mixed acid over a temperature range of -10 deg C (14 deg F) to 50 deg C (122.0 deg F) for lubricant concentrations from 0% to 45%. The data were statistically correlated and solubility equations were presented. The range of temperatures and concentrations evaluated reflects conditions typically found in a refrigeration-type evaporator or condenser.

KEYWORDS: models, data, lubricants, evaporators, condensers, refrigeration, R134a, heat exchangers, temperature, measuring, refrigerants, solubility.