The method of construction of the thermal constants (K-values) of phase equilibrium in multicomponent solutions

New analytical formulas for the phase equilibrium constants (K-values) are proposed. The theoretical approach takes into account the influence of temperature, pressure, composition and other factors on the phase behavior. It is proposed simple model equations of state and the Gibbs potentials, which well describe the phase behavior of solutions in a practically important range of pressures and temperatures. The model is contained easily computed parameters. The approach allows building a thermodynamically consistent model, which is convenient for numerical simulation of two-phase multicomponent transport in porous media: reducing the required computing resources and improving the reliability of calculations.