A corresponding state equation for compressed liquid isochoric heat capacity of pure and mixture refrigerants

This work proposed a simple corresponding state equation depending on reduced temperature to predict compressed liquid isochoric heat capacity (c_v) for HCs, HCFCs, HFCs and HFOs pure and mixtures at 0.3 < T_r < 1 and 0.5 < p_r < 10. The generalized constant coefficients A and B were determined by regression of 1738 experimental c_v data for 16 refrigerants including HCs, HFCs, HCFCs and HFOs in compressed liquid states (ρ > 2ρ_c). With known critical parameters, acentric factor and ideal gas isochoric heat capacity, the developed equation can represent the compressed liquid c_v well with the average absolute relative deviation (AARD) of 1.82%. Compared with the generalized equation of Zhong et al. (2019a) and the special multiproperty equations in REFPROP 10.0 software, the proposed equation is slightly poor in accuracy, but simpler in form and requires fewer parameters. In addition, liquid c_v data of 13 pure and 9 mixtures were used to verify the prediction performance of the developed equation and the applicability to the mixtures. The equation in this work is in good agreement with the experiment c_v data of 9 pure and 9 mixtures including HCs, HFCs, HCFCs and HFOs, but the large deviation for 4 substances (N₂, CO₂, H₂O and CH₃OH).