Determination of thermodynamic properties of refrigerants by using molecular simulation and experiment: application to development of predictive thermodynamic models.

Since 1987, several protocols have banned the use and the production of CFC’s and HCFC’s, and limited the utilization of HFC’s owing to ozone depletion and global warming. In Europe, the F-gas regulation gives the objective in terms of GWP of fluids authorized in the market. These working fluids can be pure component or blends of refrigerants with low GWP (like CO2). In all cases, the production and uses of these fluids require knowledge of thermodynamic properties in order to estimate their performance in machines and to design compressors, heat exchangers or turbines. The best strategy consists in developing predictive equations of state. These models are very useful to screen and select the best candidates for the considered application (refrigeration, heat pump, etc.). The parameters of the predictive models, mainly based on group contribution approach, have to be determined. It exists two methods to obtain thermodynamic properties: the first one consists in using molecular simulation, and the second one consists in measuring thermodynamic data experimentally. Herein, we consider the capabilities of Monte Carlo simulations in the Gibbs ensemble to provide vapor-liquid equilibrium data of refrigerant mixtures. Experimental work can be done considering techniques based on either analytic or synthetic methods.