Application of the group contribution volume translated Peng-Robinson equation of state to new commercial refrigerant mixtures
Ian H. Bell, Jonathan Welliquet, Maria Mondejar, Sylvain Quoilin, Ala Bazyleva, Frederik Haglind
The search of new refrigerants complying with the most recent environmental regulations must be supported by the availability of simple and reliable models for the prediction of their thermophysical behavior, both as pure substances and as mixtures. Cubic equations of state, and particularly the Peng-Robinson equation of state, are widely used in the refrigeration industry due to their easy applicability for new substances, and their low computational time, although generally lower prediction accuracies must be expected compared to multiparameter equations of state. The group contribution volume translated Peng-Robinson equation of state combines the Peng- Robinson equation of state with a new attraction term, improved mixing rules using a group contribution approach, and a volume translation. This work evaluates the performance of the group contribution volume translated Peng-Robinson model when predicting the vapor-liquid equilibrium and single phase densities of several commercial refrigerant mixtures with low global warming potential and zero ozone depletion potential. The results are compared with the estimates obtained using the translated, and non translated, Peng-Robinson equation of state, and a multiparameter equation of state.