Abstract: A density dependent local composition version of M-H(81) equation of state(DDLC M-H(81)) tor mixtures has been developed to improve the application of M-H(81) equation of state to VLE calculation for systems containing polar and supercritical components. It was tested with 45 sets of low-pressure and high-pressure binary VLE data. When applied to low-pressure polar systems, the new model had the same accuracy for the vapor composition and better result for the bubble point pressure as compared with the common activity-coefficient models. When applied to high-pressure systems (including those containing supercritical components) the model showed significant improvement in data correlations as compared with the conventional quadratic mixing rule.

摘要： 为了改进M-H(81)状态方程在含极性和超临界组分体系汽液平衡计算中的应用,作者将局部组成概念和M-H(81)状态方程相结合,导出了局部组成型的M-H(81)状态方程[DDLC M-H(81)];并对45组低压和高压二元汽液平衡数据进行了关联计算.结果表明:对低压极性体系,汽相组成的绝对偏差和常用的活度系数模型相当,而压力的绝对偏差则略好于上述模型.对于高压体系(包括含超临界组分体系),新模型与单流体模型相比,无论是汽相组成还是泡点压,其计算精度都有明显的改进.