An International Standard Formulation for 2,3,3,3-Tetrafluoroprop-1-ene (R1234yf) Covering Temperatures from the Triple Point Temperature to 410 K and Pressures Up to 100 MPa

A new fundamental equation of state is presented for 2,3,3,3-tetrafluoroprop-1-ene (R1234yf). The equation is valid from the triple point temperature (121.6 K) to 410 K at pressures up to 100 MPa, where typical expanded uncertainties ( k = 2) in calculated properties from the equation are 0.1 % for vapor pressures at temperatures above 270 K and 0.3 % at lower temperatures, 0.1 % for liquid densities at pressures below 40 MPa and 0.25 % at higher pressures, 0.2 % for vapor densities, 0.02 % for vapor phase sound speeds, 0.05 % for liquid phase sound speeds, 1 % for vapor phase isobaric heat capacities, 2 % for liquid phase isobaric heat capacities, and 2 % for liquid phase isochoric heat capacities. At very low temperatures around 200 K, uncertainties for vapor pressures may be larger than 0.5 %. Various plots of constant-property lines demonstrate that not only does the equation exhibit correct behavior over all temperatures and pressures within the range of validity, but also that it shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures and densities. The equation of state is the best currently available property representation for R1234yf, and has been adopted as an international standard by the ISO working group, which recently revised ISO/DIS 17584 (Refrigerant properties).