Heat capacities and Joule-Thomson coefficients of HFC refrigerants

In this report, we have examined the behavior of heat capacities and Joule- Thomson coefficients in low- and moderate-density regions based on recent t heoretical studies of the ideal-gas heat capacity and virial coefficients o f R-32, R-125, R-134a, R-143a, and R-152a. The results have been compared w ith those derived from empirical equations of state which have been recentl y developed, based on a large quantity of experimental data for these refri gerants. Both results are in good agreement. Proper behaviors for these sec ond-derivative properties justify the use of the empirical equations of sta te in low-temperature and low-density regions where no experimental data ar e available.