PREDICTION OF REFRIGERANT SURFACE PROPERTIES BASED ON THE GRADIENT THEORY WITH STATE CUBIC EQUATION

New prediction methods of the surface tension, density profile and liquid surface layer thickness closed to the vapour-liquid interface based on the gradient theory is proposed in this paper. Refrigerants are considered as research objects. New modification of Peng-Robinson’s cubic equation of state is used by authors in calculation algorithm for surface properties, which doesn’t require information about critical parameters. A new method for calculation of influence parameter is offered. Being carried out verification of methodology for prediction of liquid surface properties shows that the calculated values of surface tension of refrigerants are in agreement with presented in the literature information with enough accuracy for practical applications.