Measurements of PVTx and saturation properties for the binary 1,1,1,2-tetrafluoroethane plus propane system

Natural refrigerants such as hydrocarbons (HCs) are considered as promising long-term alternatives in some of the restricted applications for refriger ation systems, since they have zero ozone depletion potential (ODP) values and negligible global warming potential (GWP) values. One of the crucial di sadvantages of HCs, however, is flammability. For the purpose of solving th is important issue, we have decided to study the thermodynamic properties o f binary mixtures of HCs blended with. nonflammable HFC refrigerants. The p resent paper, therefore; aims to measure a set of reliable PVTx property da ta for the binary 1,1;1,2-tetrafluoroethane (R-134a) + propane (R-290) mixt ures in two-phase and gas-phase regions. The experimental PVTx properties o f the binary R-134a + R-290 system have been measured at four different com positions by a constant-volume method coupled with expansion procedures in an extensive range of temperatures from 312 K to 400 K, at pressures up to 6.1 MPa, and for densities up to 196 kg.m(-3), respectively. The present st udy also aims to determine the dew-point pressures and the saturated-vapor densities of the present binary mixtures so as to develop a virial equation of state in the gaseous phase of the binary R-134a + R-290 system.