Prediction Of Refrigerant Thermodynamic Properties By Equations Of State

Abstract

The ability of three equations of state (EOS) for calculating the thermodynamic properties of refrigerants has been studied for 35 pure component refrigerants. Three equations of state studied were the Soave-Redlich-Kwong (SRK), Peng-Robinson (PR) and Parameters From Group Contribution (PFGC). For each refrigerant, the vapor pressure, saturated vapor volume, saturated liquid density, and heat of vaporization were calculated and compared with the values reported in the ASHRAE hand-book. For each refrigerant a range of temperature from about the triple point to the critical point was covered. Specific EOS parameters such as acentric factor (for SRK and PR), b. s, E"" E"', E12' (for PFGC) were optimized to achieve better agreement between calculated values and the ASHRAE data. The optimized acentric factors and PFGC parameters for several compounds are presented. Sample graphical error analyses are shown.