扩展UNIQUAC方程求NH_3-CO_2-H_2O-urea体系液相活度系数的新方法  

New Approach to Calculate the VLE of NH_3-CO_2-H_2O-Urea System with Extended UNIQUAC Equation

作　　者：张香平[1] 孙力[1] 姚平经[1] 袁一[1] 

机构地区：[1]大连理工大学化工学院

出　　处：《高校化学工程学报》2002年第4期355-360,共6页Journal of Chemical Engineering of Chinese Universities

摘　　要：扩展UNIQUAC方程是求弱电解质体系液相活度系数的有效方法。基于该方法,将“物种群”的概念引入扩展UNIQUAC方程中用于求解NH3-CO2-H2O-urea体系的液相活度系数,以“物种群”间的交互作用参数代替实际物种间的交互作用参数, 从而减少参数个数,简化了模型,该方法为求解多组分易挥发弱电解体系的汽液相平衡提供了一种新的方法。对尿素流程中低压范围的NH3-CO2-H2O-urea体系的汽液平衡进行了模拟计算,并同实际数据进行了比较。模型计算所得平衡气相压力值与实验值的平均相对误差为12.36%,优于Isla原模型计算的相对误差值(15.95%)。采用该模型对汽提液进行闪蒸计算,结果同设计数据吻合较好。The vapor-liquid equilibrium data are of great importance to urea process simulation. Based on the extended UNIQUAC equation which is commonly used to calculate the liquid activity coefficients of volatile electrolyte system, the 揼roups of species?was proposed to replace the real species and it makes the number of interaction parameters used in the equation for the multicomponent volatile electrolyte system obviously reduced. Using this 'groups of species' approach, the vapor-liquid equilibrium(VLE)of NH3-CO2-H2O-Urea system in the range of middle and low pressure was calculated and the simulating calculation of the flash of stripping solution was also made. Those calculation results were compared with the experimental data. It showed that the new approach had a good accuracy.

关 键 词：扩展UNIQUAC方程 汽液相平衡 液相活度系数 NH3-CO2-H2O-urea体系 尿素工业 热力学体系 氨 二氧化碳 水 

分 类 号：TQ441.41[化学工程—化学肥料工业] TQ013.1