TY - JOUR

T1 - Helmholtz energy and extended corresponding states model for the prediction of thermodynamic properties of mixtures of refrigerants

AU - Estela-Uribe, Jorge F.

PY - 2014/9/25

Y1 - 2014/9/25

N2 - This work was concerned with developing an accurate model for the prediction of thermodynamic properties of mixtures of refrigerants. That model was the extension to mixtures of a recent work by the author about a Helmholtz and extended corresponding states model for refrigerants. In the proposed model the residual Helmholtz energy of the mixture was expressed as the contribution of three terms: one from an extended corresponding states model and the other two were corrections in terms of one-fluid mixing rules of functions of reduced temperature and density. The extended corresponding states model was based on the temperature- and density-dependent shape factors that the author has presented previously in the literature and the reference fluid was R-32 with properties calculated with the Tillner-Roth and Yokozeki reference equation of state. The fluids of interest were six binary systems and two ternary systems: (R-32+R-125), (R-32+R-134a), (R-125+R-134a), (R-125+R-143a), (R-134a+R-143a), (R-134a+R-152a), (R-32+R-125+R-134a) and (R-125+R-134a+R-143a). The following were the obtained percentage overall average absolute deviations: 0.347 in pρT data, 1.836 in isochoric heat capacities, 1.108 in isobaric heat capacities, 0.073 in speeds of sound, 0.467 in bubble-point saturation pressures and an overall average absolute difference of 3.367cm3mol-1 was obtained in second virial coefficients. These results compared satisfactorily with those from other models for mixtures of refrigerants.

AB - This work was concerned with developing an accurate model for the prediction of thermodynamic properties of mixtures of refrigerants. That model was the extension to mixtures of a recent work by the author about a Helmholtz and extended corresponding states model for refrigerants. In the proposed model the residual Helmholtz energy of the mixture was expressed as the contribution of three terms: one from an extended corresponding states model and the other two were corrections in terms of one-fluid mixing rules of functions of reduced temperature and density. The extended corresponding states model was based on the temperature- and density-dependent shape factors that the author has presented previously in the literature and the reference fluid was R-32 with properties calculated with the Tillner-Roth and Yokozeki reference equation of state. The fluids of interest were six binary systems and two ternary systems: (R-32+R-125), (R-32+R-134a), (R-125+R-134a), (R-125+R-143a), (R-134a+R-143a), (R-134a+R-152a), (R-32+R-125+R-134a) and (R-125+R-134a+R-143a). The following were the obtained percentage overall average absolute deviations: 0.347 in pρT data, 1.836 in isochoric heat capacities, 1.108 in isobaric heat capacities, 0.073 in speeds of sound, 0.467 in bubble-point saturation pressures and an overall average absolute difference of 3.367cm3mol-1 was obtained in second virial coefficients. These results compared satisfactorily with those from other models for mixtures of refrigerants.

KW - Bubble-point vapour pressures

KW - Densities

KW - Extended corresponding states models

KW - Helmholtz energy models

KW - Mixtures of refrigerants

UR - http://www.scopus.com/inward/record.url?scp=84904862395&partnerID=8YFLogxK

U2 - 10.1016/j.fluid.2014.06.027

DO - 10.1016/j.fluid.2014.06.027

M3 - Article

AN - SCOPUS:84904862395

SN - 0378-3812

VL - 378

SP - 60

EP - 72

JO - Fluid Phase Equilibria

JF - Fluid Phase Equilibria

ER -