Correction and expansion of the Fa-input box equation (2) Phase equilibrium calculation of polar Wu tin such as ammonia, methanol and so on

Abstract

 On the basis of the previous article, based on the vapor-liquid two-phase PVT data of ammonia, water, and methanol, as the objective function, the F-SRK equation was used to fit the eccentricity factor correction calculation formulas (27), (27), ( 28) and (29). In the range of Tr=0.42~1, the relative errors of PS and VL calculation are 2.06% and 3.59% respectively, =0.0053; the relative error of evaporation enthalpy calculation is 3.29%. Compared with the original Fuller calculation results using the ω value in the literature, the accuracy of PS and VL calculations is retained, but the calculation error is reduced by an order of magnitude, and the evaporation enthalpy calculation error is reduced by 37%. Then the method mentioned above is extended to the calculation of phase equilibrium of mixtures containing polarity. The 195-point T-P-X-Y data calculation results of six polar-polar and polar-non-polar binary systems show that the absolute average calculation error of vapor phase composition y is 1.03%, and the 179-point T-P-X of six gas-polar solvent binary mixtures The data calculation results show that the absolute average calculation error of steam point pressure is 2.48 atm. For the phase equilibrium calculation of the mixture of supercritical gas and polar solvent, it is recommended to use T-P-X-Y data as much as possible and use kij as the linear function of T for fitting.