An equation of state for 1,1,1-trifluoroethane (R-143a)

A fundamental equation of state has been developed for 1,1,1-trifluoroethan e (R-143a) using the dimensionless Helmholtz energy. The experimental therm odynamic propel ty data, which cover temperatures from the triple point (16 1 K) to 433 K and pressures up to 35 MPa, are used to develop the present e quation. These data are represented by the present equation within their re ported experimental uncertainties: +/-0.1% in density for both vapor and li quid phase P-p-T data, +/- 1 % in isochoric specific heat capacities, and /-0.02% in the vapor phase speed-of-sound data. The extended range of valid ity of the present model covers temperatures from 160 to 650 K and pressure s up to 50 MPa as verified by the thermodynamic behavior of the isobaric he at-capacity values over the entire fluid phase.