Generalized volumetric behaviour of refrigerants based on a new four-parameter corresponding states correlation

The generalized volumetric behaviour of polar and non-polar refrigerants has been correlated using a new four-parameter corresponding states method. This method results in an accurate representation of the PVT surface for reduced temperatures from 0.55 to 1.62 and for reduced pressures up to 23.5, which covers almost all the range of importance for refrigerant applications. Input parameters required are critical temperature, critical pressure, the acentric factor and a pseudo-polarity factor calculated from the compressibility factor of a saturated liquid at a reduced temperature of 0.7. Three reference fluids are used to evaluate the compressibility factors. Comparison between experimental and calculated volumetric properties shows that highly accurate results are obtained by the new method for 20 polar of non-polar substances that are mainly used as working fluids in refrigeration systems and heat pumps. Average errors in the calculation of compressibility factors are 0.63, 2.24 and 0.53% for the gaseous, critical and liquid regions, respectively. Overall average error is 0.91% for the entire region studied.