流动平衡釜汽液平衡数据的关联与讨论

Correlation and Discussion of Vapor—Liquid Equilibrium Data Determined in Flow Still

对流动平衡釜所测定的汽液平衡数据的关联、目标函数的选取、模型的选取以及回归方法等进行了探讨。用本作者建立的方法对模型参数进行了回归。目标函数分别采用相对挥发度误差平方和、汽相组成误差平方和;活度系数模型选用 Wilson方程和 UNIQUAC 方程;计算方法采用非线性最小二乘法。结果表明:计算方法可行,平均汽相偏差(△y)小于0.01,为分离工程设计和开发提供了方便。同时还看到,两种目标函数、两种模型均能很快收敛。以汽相组成误差平方和为目标函数,其总平均汽相偏差较小,但对初值的给予要求较高。

The correlation of binary vapor-liquid equilibrium (VLE) data determi-ned by using of the flow still at constant temperature was discussed.Twokinds of objactive functions and nonlinear least square method were appliedto correlate model parameters of Wilson and UNIQUAC equation respective-ly.21 binary flow still VLE data were correlated by this method.The res-ults indicate that this method is good in convergency and accuracy for thecorrelation of flow still VLE data.And the mean deviation of vapor com-position (Δy is less than 0.01 (mole fraction),this precision meets therequirement of engineering design.