Abstract: The real state of vapor liquid equilibria is considered as a combination of three fictitious states. From the relation between the real state and three fictitious states, the approximatep, y, x relationship can be obtained from these fictitious states with the help of the Gibbs-Duhem equation. This method was used to calculate isothermal high (low) pressure vapor liquid equilibria with satisfactory results, while no equations of state or equations of activity coefficients were needed.

摘要： 把汽液平衡的真实状态看成是3个虚拟状态的组合,结合Gibbs-Dubem方程,推得了等温低压汽液平衡时p-y-x之间的一个近似关系式,并把它推广应用到加压及含超临界组分体系的汽液平衡计算.