A new crossover equation of state in the dimensionless Helmholtz free energy for the thermodynamic properties of 1, 1,1 ) 2-tetrafluoroethane (R 134a ) has been developed that incorporates singular thermodynamic behav...A new crossover equation of state in the dimensionless Helmholtz free energy for the thermodynamic properties of 1, 1,1 ) 2-tetrafluoroethane (R 134a ) has been developed that incorporates singular thermodynamic behavior near the critical point with regular thermodynamic behavior far from the critical point. The equation of state is capable of representing all the thermodynamic properties of R134a including press ure-density-temperature properties, the isochoric and isobaric heat capacities, and the sound velocity in the entire region,at temperatures from the triple point to 453K, pressures up to 70MPa and densities from zero to three times and a half the critical density. The results have been compared with experimental thermodynamic-property data in the entire region and with other equations of state near the critical point.展开更多
文摘A new crossover equation of state in the dimensionless Helmholtz free energy for the thermodynamic properties of 1, 1,1 ) 2-tetrafluoroethane (R 134a ) has been developed that incorporates singular thermodynamic behavior near the critical point with regular thermodynamic behavior far from the critical point. The equation of state is capable of representing all the thermodynamic properties of R134a including press ure-density-temperature properties, the isochoric and isobaric heat capacities, and the sound velocity in the entire region,at temperatures from the triple point to 453K, pressures up to 70MPa and densities from zero to three times and a half the critical density. The results have been compared with experimental thermodynamic-property data in the entire region and with other equations of state near the critical point.
