中文摘要：

最优粒子群算法（PSO）近年在非线性方程模拟计算中广泛应用。应用文献报道的Pitzer方程参数与温度的关联方程计算了323 K时该四元体系中有关盐的Pitzer方程单盐参数、混合离子相互作用参数和盐的溶解平衡常数K,在此基础上应用Matlab工程计算软件和粒子群优化算法（PSO）编写了相应的Pitzer方程计算程序,对323 K时四元体系Na^＋,K^＋//Cl^-,SO4^2--H2O的溶解度数据进行理论模拟计算,并用计算出的溶解度数据绘制出该四元体系323 K时的相图。计算结果表明,溶解度的模拟计算值与实验值吻合较好,验证了该算法的适用性和实验数据的可靠性,同时也表明含有合理Pitzer模型参数的PSO算法程序可以计算多温条件下的水盐体系相平衡关系。

英文摘要：

Particle Swarm Optimization（PSO） is widely used in calculating the nonlinear equations in recent years.Using the correlation equation of the Pitzer parameters with temperature,the single parameters,mixed parameters and equilibrium constants of salts in the quaternary system Na^＋,K^＋//Cl^-,SO4^2--H2O at 323 K were calculated,respectively.The corresponding Pitzer＇ s equation calculation programs were prepared by using Matlab and Particle Swarm Optimization（PSO）.The solubilities of salts in the quaternary system Na^＋,K^＋//Cl^-,SO4^2--H2O at 323 K were calculated by Pitzer＇ s equation,and the phase diagram of the quaternary system was plotted.The results show that the calculated values are in good agreement with the measured experimental data.The applicability of PSO algorithm and the reliability of experimental data are verified.The calculation results also show that PSO algorithm with reasonable Pitzer＇ s parameters can be used to calculate the phase equilibria of salt-water system at different temperatures.