THERMODYNAMIC PROPERTIES OF 2 ALTERNATIVE REFRIGERANTS - 1,1-DICHLORO-2,2,2-TRIFLUOROETHANE (R123) AND 1,1,1,2-TETRAFLUOROETHANE (R134A)

This paper describes two different sets of measurements of the properties of two proposed alternative refrigerants, 1,1,1,2-tetrafluoroethane (R134a) ** and 1,1-dichloro-2,2,2-trifluoroethane (R123) **. The first are vapor-liquid equilibrium measurements made in a simple variable-volume sapphire cell. The vapor pressures and saturation liquid densities were determined for both materials, between 268 K and the critical temperature for R134a and between 303 K and 373 K for R123. The saturation vapor density was also determined for R134a from 298 K to the critical point, where the critical conditions were measured. The second set of measurements were made with a vibrating tube densimeter from the saturation pressure to 5500 kPa for R134a and to 3500 kPa for R123 in the temperature range 278 K-368 K. These data are then compared with other determinations of similar properties.