3660 -- Measurement of Pressure-Temperature-Concentration Relations for Mixtures of R-12/Mineral Oil and R-134a Synthetic Oil PDF

A test facility was constructed to measure the pressure-temperature-concentration relations for mixtures of refrigerant and oil. Baseline data were collected for mixtures of dichlorodifluoromethane (R12) and two mineral oils at concentrations from 1% to 100% R12 (by mass) over the temperature range of -50 deg F (-46 deg C) to 250 deg F (121 deg C). Data were also collected for mixtures of tetrafluoroethane (R134a) and two synthetic oils at concentrations from 5% to 100% R134a over the same temperature range. These data were used to develop empirical relations to predict the solubility behaviour of these refrigerant-oil mixtures. Experimental data were also compared with Raoult's rule and the Flory-Huggins theory. Comparison between these empirical and theoretical models shows that the empirical correlations are significantly more accurate at predicting solubility relations at conditions of equilibrium.

KEYWORDS: measuring, pressure, temperature, content, mixtures, refrigerants, R12, R134a, oils, testing, solubility, behaviour, comparing, accuracy, equilibrium, fluorocarbons, lubricants.