A simple generalized equation for compressed liquid isochoric heat capacity of pure and mixture refrigerants

Abstract

This work aims to develop a generalized equation for compressed liquid isochoric specific heat capacity (cv). The form of the equation was proposed based on the isochoric specific heat capacity calculation equation derived by the Peng-Robinson equation of state. The generalized coefficients were determined by 1734 liquid experimental cv data from 17 refrigerants. With known critical point, acentric factor and idea gas isochoric specific heat capacity, the developed equation can represent the liquid cv of 17 refrigerants well with the average absolute relative deviation of 1.55%. Large deviations are most likely to appear near the critical point. Comparisons were made to the calculation deviations from the Peng-Robinson equation of state and the multiproperty equations in REFPROP 9.1 software. It indicates that the developed equation provide a simple and reliable method for the calculation of the liquid cv. Additionally, 9 mixture refrigerants were calculated by the proposed generalized equation with the average absolute relative deviation of 3.13%.