Investigation of ternary vapor-liquid equilibrium for refrigerant mixtures containing HFOs: Simple and accurate predictive models

The refrigeration industry is committed to developing high-performance, environmentally friendly mixed refrigerants to reduce greenhouse gas emissions . A large amount of ternary vapor-liquid equilibrium (VLE) data are required to design and optimize refrigeration systems if a ternary mixture is used as the refrigerant while the efficiency in design and optimization could be improved by accurate ternary VLE predictions. This paper aims to develop an approach to accurately predict ternary VLE for mixtures containing low-GWP hydrofluoroolefin (HFO). Two models, the PRMC model and PPR78 model are utilized respectively for the ternary VLE prediction validation of 13 binary and 3 ternary systems and subdivided into four methods PRMC-T, PRMC-Avg, PPR78-T and PPR78-Avg according to their different models and binary interaction parameters ( k ij ). The k ij of PRMC model is correlated from literature data, and the obtained k ij is used to fit group-interaction parameters ( A k l and B k l ) of PPR78 model. The accuracy of PRMC and PPR78 models are validated based on the literature data, and the results in VLE predictions are carefully analyzed and discussed.