Thermodynamic studies on refrigerants: apparatus, data and modelling.

An apparatus is described to obtain VLE data simultaneously with volumetric properties in a range of pressures from vacuum to 20 MPa and between 253 and 423 K. It is based on a synthetic open-flow method and allows recording a considerable amount of data, among them: saturated liquid and vapour densities, dew and bubble pressures for mixtures. The experimental results of the authors' laboratory for two pure compounds (R32 and R125) and their mixtures are treated with literature data. Several models are used: a virial type, two cubic equations of state and a neural network. Performances of these models are compared and discussed.