Extention of the predictive E-PPR78 equation of state to freon-containing systems.

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) have a high ozone depletion potential (ODP) and hydrofluorocarbons (HFCs) are high global warming potential (GWP) refrigerants. Consequently, refrigeration and air conditioning industries carry out extensive researches to find highly efficient alternative refrigerants with zero ODP and GWP lower than 150. The search for next-generation refrigerants requires the preselection of good candidate likely to exhibit low environmental impact and leading to high thermodynamic cycle efficiency. To do so, disposing of powerful predictive thermodynamic models is a necessary prerequisite. In this work, the well-established E-PPR78 predictive equation of state was extended to systems containing freons. Therefore, 6 different groups were added to the 21 already-existing groups: group 22: CF3-CF3 (R116), group 23: -CF3, group 24: -CF2, group 25: =CF2 / =CF-, group 26: CHF2-CH3 (R152a), group 27: CF3-CH2F (R134a). All the experimental data available in the open literature were then selected to estimate the various group interaction parameters between the 6 new groups and the 21 previously defined.