Solid−Liquid Equilibria for the Carbon Dioxide + 1,1-Tetrafluoroethane and Nitrous Oxide + 1,1-Tetrafluoroethane Systems

A recently built experimental setup was employed for the estimation of the solid−liquid equilibria of alternative refrigerant systems. The behavior of two binaries, i.e., carbon dioxide + 1,1-tetrafluoroethane (CO 2 + R134a) and nitrous oxide + 1,1-tetrafluoroethane (N 2 O + R134a), was measured down to temperatures of 142 K. The triple points of CO 2 and N 2 O were measured to confirm the reliability of the apparatus. The triple point of R134a was also measured; however, the pressure at the triple point for this fluid was too low to be accurately measured with the current apparatus. All triple point data measured revealed a generally good consistency with the literature. The results obtained for the mixtures were interpreted by means of the Schröder equation.