Thermodynamic properties of the R-415A refrigerant in the vapor phase and on the condensation line

The speed of sound in the R-415A refrigerant vapor and its density and pressure on the condensation line were measured by the ultrasonic interferometer and constant-volume piezometer methods within a range of temperatures from 293 to 373 K and pressures from 0.04 to 0.5–2.45 MPa. The temperature, pressure, density and speed of sound measurement errors were ±20 mK, ±4 kPa, and ±(0.1–0.2)%, respectively. The temperature dependence of the ideal-gas heat capacity was calculated on the basis of the obtained data. The obtained results were compared with the properties calculated by the REFPROP software.