A NEWEQUATION OF STATE FOR 1,1,1,3,3-PENTAFLUOROPROPANE (R-245fa)

摘要

A new fundamental equation of state explicit in the Helmholtz energy is presented for 1,1,1,3,3-pentafluoropropane(R-245fa). The functional form uses Gaussian bell-shaped terms, according to recent trends in the development ofaccurate equations of state. The equation is valid for temperatures between the triple point (170.0 K) and 440 K, andfor pressures up to 200 MPa. Estimated uncertainties in this range are 0.1 % for vapor pressures, 0.1 % for saturatedliquid densities, 0.1 % for liquid densities below 70 MPa, 0.2 % for densities at higher pressures, 0.3 % for vapordensities, 0.3 % for liquid sound speeds, and 0.1 % for vapor sound speeds. The uncertainties in the critical region arehigher for all properties except vapor pressures. The equation shows reasonable extrapolation behavior at extremelylow and high temperatures, and at high pressures.