Extension of the Implicit Curve-Fitting Method for Fast Calculation of Thermodynamic Properties of Subcooled Refrigerants

摘要

Researchers want refrigerant thermal property calculations to be both quick and reliable when simulating refrigeration systems. The implicit regression and explicit calculation method allows for the fast and stable calculation of refrigerant thermodynamic properties of saturated, two-phase, and superheated refrigerants. In this paper, this method was improved upon so it could be used with subcooled refrigerants. As an example, the fast calculation formulae and the developing process for subcooled R-134a and R-410A are given. A comparison with REFPROP 8 (Lemmon et al. 2007) shows that for R-134a the total mean relative deviations of the fast calculation formulae are less than 0.2% and the maximum relative deviations are less than 5.8%. For R-410A, the total mean relative deviations of the fast calculation formulae are less than 0.8% and the maximum relative deviations are less than 4.5%. The mean calculation speeds of the fast calculation formulae for R-134a and R-410A are nearly 100 times and greater than 1500 times faster than those of REFPROP 8, respectively.