An International Standard Formulation for trans-1-Chloro-3,3,3-trifluoroprop-1-ene [R1233zd(E)] Covering Temperatures from the Triple-Point Temperature to 450 K and Pressures up to 100 MPa

A new Helmholtz energy equation of state is presented for trans-1-chloro-3,3,3-trifluoroprop-1-ene [R1233zd(E)], which is expressed with temperature and density as independent variables. Experimental data in the range of temperatures from 215 to 444 K and pressures up to 35 MPa form the basis of the new equation. In this range, expected uncertainties ( k = 2) of the new equation of state are 0.07% for vapor pressures at temperatures above the normal boiling point temperature [Formula: see text], 0.2% for vapor pressures at lower temperatures, 0.05% for liquid densities, 0.15% for vapor densities, 0.1% for saturated liquid densities, 0.05% for liquid-phase sound speeds, and 0.08% for vapor-phase sound speeds. The new equation is valid at temperatures from the triple-point temperature (165.75 K) to 450 K and pressures up to 100 MPa with reasonable uncertainties outside the available range of data because it fully extrapolates with correct physical behavior to higher temperatures and pressures as well as to lower temperatures. The equation of state presented here has been recommended as an international standard by the working group presently revising ISO 17584 (Refrigerant Properties).