Vapor Pressure, Speed of Sound, and Density of the Refrigerant Mixture R-134a–R227ea in Vapor Phase

Abstract

The vapor pressure on the bubble line, the speed of sound, and the density of the R-134a (48.66%)–R-227ea (51.34%) refrigerant gaseous mixture were studied with an ultrasound interferometer and constant volume piezometer within the temperature range of 293–373 K at pressures of 0.06 to 0.4–3.6 MPa. The temperature, pressure, speed of sound, and density measurement errors were ±20 mK, ±4 kPa, ±(0.1–0.3)%, and ±(0.2–0.4)%, respectively. The approximation dependencies of the vapor density and its pressure on the bubble line were obtained, and the experimental data are compared to calculations with the REFPROP software.