Method for discriminating and calculating thermodynamic state of supercritical fluid

The invention discloses a supercritical fluid thermodynamic state discrimination and calculation method, which belongs to the technical field of thermodynamic state discrimination and calculation, and comprises the following steps: step 1, solving a gas-liquid phase equilibrium line of a binary system through a cubic state equation and a mixing rule; 2, determining a critical mixing point of the binary system under each environment pressure condition; 3, solving the constant-pressure specific heat capacity of the binary system under each environment pressure condition, and determining the thermodynamic state corresponding to the peak value of the constant-pressure specific heat capacity; 4, determining a critical mixing line and a critical component line under each environment pressure according to the obtained critical mixing point, and determining a pseudo-boiling line according to the thermodynamic state corresponding to the constant pressure specific heat capacity peak value under each environment pressur