应用遗传算法求解含化学反应体系的相平衡

COMPUTATION ALGORITHM FOR SIMULTANEOUS CHEMICAL AND PHASE EQUILIBRIUM BY USING GENETIC ALGORITHM

基于Gibbs自由能最小原理 ,提出一种求解含化学反应体系相平衡的方法。采用反应进度和相分率消去等式约束 ,将含化学反应体系的相平衡计算转化为无约束的最优化问题 ,并应用遗传算法求解。采用本文提出的方法 ,能够避免计算中负数的组分摩尔数或摩尔分数的出现 ,确保得到组分的摩尔数或摩尔分数为非负的全局最优解。以聚甲醛反应体系的汽液平衡计算为例 。

A computation algorithm for simulataneous chemical and phase equilibrium is proposed based on minimization of Gibbs free energy. By using the extent of reaction and the yield factor of phase, the computation of simultaneous chemical and phase equilibrium is transformed into unconstrained nonlinear minimization problem, and is solved by Genetic Algorithm. The proposed algorithm has a wide application prospect because in this algorithm the variables are less, and negative mole-fraction, which usually appears in conventional algorithms, will not occur, and it can obtain a global optimization solution. The formaldehyde-water system is taken as an example. It is found that the computation results are just the same as those reported in the literature, which shows that the presented algorithm is robust and efficient.