On the Calculation of the Virial Coefficients and Low-Pressure Joule-Thomson Effect for Refrigerant Fluids Using Two Equation of State Models

In this study, we calculate virial coefficients and the Joule-Thomson effect at low pressure for refrigerant fluids in order to evaluate the performance of two models of Equations of State (EOS). The studied refrigerants are R123, R124, R143a, and R152a. The investigated EOSs are van der Waals type consist of van der Waals (vdW), Redlich-Kwong (RK), Soave- Redlich-Kwong (SRK) and Peng-Robinson (PR). In our work, we use Dieterici model of EOS consisting of Dieterici (D) and Dieterici-Carnahan-Starling (DCS). The obtained results show that all EOSs predict the qualitative behavior of the second virial coefficient of refrigerants in wide range temperatures but, cannot provide the qualitative behavior of the third virial coefficient of refrigerants in T£ Tc in comparing with experimental data. Quantitatively, the EOSs on the basis of vdW model present good results in a wide range of temperatures. Both models of equations of state can also predict the qualitative behavior of changing the low-pressure J-T coefficient with respect to temperature. Our study shows that the EOSs on the basis of vdW model, especially PR, present better results than the other model in a wide range of temperatures.