TY - JOUR
T1 - Peng-Robinson-based association equation of state for mixtures of hydrofluorocarbon refrigerants
AU - Estela-Uribe, Jorge F.
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/1/25
Y1 - 2019/1/25
N2 - The objective of this work was to extend to mixtures of hydrofluorocarbon refrigerants a recently developed Peng-Robinson plus association equation of state for those compounds. In that equation of state, two terms constituted the residual dimensionless Helmholtz energy: the first was a substance-specific dimensionless form of the conventional Peng-Robinson equation while the second was the association term from the Statistical Associating Fluid Theory. The extension to mixtures consisted of the conventional Peng-Robinson equation to mixtures, i.e. the expressing the mixture attractive parameter as a van der Waals one-fluid mixing rule with a binary interaction parameter at the unlike-interaction term. The systems of interest were the mixtures systems (HFC-32 + HFC-125), (HFC-32 + HFC-134a), (HFC-125 + HFC-134a), (HFC-125 + HFC-143a), (HFC-134a + HFC-143a), and (HFC-134a + HFC-152a); and the ternary systems (HFC-32 + HFC-125 + HFC-134a) and (HFC-125 + HFC-134a + HFC-143a). For the important number of 98000 data, the percentage overall average absolute deviations obtained were 1.44 in pρT; 53.9 in isochoric heat capacities, 34.8 in isobaric heat capacities, 0.183 in speeds of sound, and 1.27 in bubble-point vapour pressures; and an overall average absolute difference in second virial coefficients of 41.4 cm3.mol−1. Those results compared favourably with those obtained with the standard Pang-Robinson equation, with a substance-specific version of the Pang-Robinson equation, and with a cubic plus association equation.
AB - The objective of this work was to extend to mixtures of hydrofluorocarbon refrigerants a recently developed Peng-Robinson plus association equation of state for those compounds. In that equation of state, two terms constituted the residual dimensionless Helmholtz energy: the first was a substance-specific dimensionless form of the conventional Peng-Robinson equation while the second was the association term from the Statistical Associating Fluid Theory. The extension to mixtures consisted of the conventional Peng-Robinson equation to mixtures, i.e. the expressing the mixture attractive parameter as a van der Waals one-fluid mixing rule with a binary interaction parameter at the unlike-interaction term. The systems of interest were the mixtures systems (HFC-32 + HFC-125), (HFC-32 + HFC-134a), (HFC-125 + HFC-134a), (HFC-125 + HFC-143a), (HFC-134a + HFC-143a), and (HFC-134a + HFC-152a); and the ternary systems (HFC-32 + HFC-125 + HFC-134a) and (HFC-125 + HFC-134a + HFC-143a). For the important number of 98000 data, the percentage overall average absolute deviations obtained were 1.44 in pρT; 53.9 in isochoric heat capacities, 34.8 in isobaric heat capacities, 0.183 in speeds of sound, and 1.27 in bubble-point vapour pressures; and an overall average absolute difference in second virial coefficients of 41.4 cm3.mol−1. Those results compared favourably with those obtained with the standard Pang-Robinson equation, with a substance-specific version of the Pang-Robinson equation, and with a cubic plus association equation.
KW - Association equation of state
KW - Bubble-point vapour pressures
KW - Densities
KW - Hydrofluorocarbon mixtures
KW - Peng-Robinson plus association
UR - http://www.scopus.com/inward/record.url?scp=85054822953&partnerID=8YFLogxK
U2 - 10.1016/j.fluid.2018.10.004
DO - 10.1016/j.fluid.2018.10.004
M3 - Article
AN - SCOPUS:85054822953
SN - 0378-3812
VL - 480
SP - 11
EP - 24
JO - Fluid Phase Equilibria
JF - Fluid Phase Equilibria
ER -