多相多组分体系相平衡计算的改进τ因子法

Equilibrium calculation of multiphase and multicomponent system by using modified τ-method

提出了一种多相平衡计算的改进τ因子法,该方法基于一种修正各相摩尔分数和的概念,研究模型的建立和用遗传算法计算多组分复杂体系的相平衡问题。首先通过建立数学模型,将相平衡计算问题转化为带线性约束的非线性规划(NLP)问题;其次用遗传算法对模型进行求解,并通过对优化变量采取动态边界的可行域编码方法保证了算法的有效实施;最后对2个体系的计算表明,结果与文献值相吻合,且此方法不仅可以求解不含化学反应体系的相平衡问题,也同样适用于含化学反应体系的相平衡计算,是一种比较可靠和通用的方法。

Based on modifying the mole fraction summation, an improved τ-method was proposed for computing muhiphase equilibrium of muhicomponent system by using Genetic Algorithm （GA）. Firstly, by establishing the mathematic model, the computation of muhiphase equilibrium was transformed into non-linear programming （NLP） with linear constraints. Secondly, the model was solved by GA, and a dynamic coding method that can limit the bounds of optimized variables within their feasible region was applied in carrying out the algorithm. Finally, two systems were taken as examples. It shows that the calculated results agree well with those reported in the literature, and the method is applicable for computing not only phase equilibrium but also simultaneous chemical and phase equilibrium, which indicates that the presented method is reliable and general for such problems.