DA-00-10-1 (RP-997) -- A Fundamental Equation for the Calculation of the Thermodynamic Properties of Trifluoromethane (R23) PDF

A formulation for the thermodynamic properties of trifluoromethane (R-23) is presented. The equation is valid for single-phase and saturation states from the triple point, -115.13°C (-247.23°F) to 200°C (392°F) at pressures up to 120 MPa (17,400 psia). The formulation includes a fundamental equation and ancillary functions for the estimation of saturation properties. The experimental data used to determine the fundamental equation included pressure-density- temperature (P-r-T), isobaric heat capacity (C _r - P-T), isochoric heat capacity (C _v -r-T), saturated heat capacity (C _sat), speed of sound (w-P-T), and vapor pressure. Saturation values computed from the ancillary functions were used to ensure thermodynamic consistency at the vapor-liquid phase boundary. Comparisons between experimental data and values computed using the formulation are given to verify the uncertainties in the calculated properties. The formulation presented may be used to compute densities to within ±0.2%, heat capacities to within ±1%, speed of sound to within ±0.5%, and saturation values to within ±0.2%, except near the critical point.

Units: Dual