The speed of sound in vapor phase refrigerant R-134a (57.24 wt.%)−R-227ea (42.76 wt.%)

Abstract

The speed of sound of the gaseous mixed refrigerant R-134a (57.24 wt.%) - R-227ea (42.76 wt. %) was investigated by the method of ultrasonic interferometer in the temperature range from 293 to 373 K and at pressures from 0.08 to 0.97 MPa. The measurement errors of temperature, pressure, and speed of sound were ±20 mK, ±4 kPa, and ±(0.20-0.35) %, respectively. Approximation dependences of the speed of sound on five isotherms have been obtained, and the experimental data have been compared with calculations using the REFPROP program.