Measurements and modeling of the vapor–liquid equilibrium properties of low-global-warming-potential refrigerant R32/R1234yf/R1123 ternary mixtures

Abstract

There is an urgent need to replace existing refrigerants that have significant greenhouse effects with next-generation, low-global-warming-potential refrigerants. Various multi-component refrigerant mixtures are potential candidates to reduce the flammability and/or toxicity and improve the compatibility with lubricating oils while preserving the refrigerant performance. In this study, for R1123/R1234yf/R32 ternary mixtures, we performed two types of accurate measurements of the vapor–liquid equilibrium properties and attempted to verify the reliability of two types of thermodynamic property models. Measurements were conducted at temperatures from 303.15 to 328.15 K and at saturation pressures of up to 3.7 MPa. The expanded uncertainties (k = 2) of the temperature, pressure, and composition measurements were estimated to be less than 0.03 K, 1.4 kPa, and 0.43 mol%, respectively. Two of the models used were the well-known and well-established Helmholtz free energy equations of state. We used these equations of state to predict the vapor–liquid equilibrium data of the ternary mixtures. The predicted values and measured results of the ternary mixtures were systematically compared, and the most reliable numerical values of the vapor–liquid equilibrium properties for these ternary mixtures and the necessity for improvement of the recent models were clarified.