基于无穷压力为参考态的超额自由能混合规则  

NEW EXCESS FREE ENERGY MIXING RULE BASED ON THE INFINITE-PRESSURE AS REFERENCE STATE

作　　者：韩晓红[1] 陈光明[1] 王勤[1] 

机构地区：[1]浙江大学玉泉校区制冷与低温研究所,浙江杭州310027

出　　处：《工程热物理学报》2006年第6期905-907,共3页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50276054);浙江省自然科学基金资助项目(No.Z105034)

摘　　要：本文从超额Helmholtz自由能的热力学一般关系式出发,给出了一个以无穷压力为参考态的,具有良好理论基础的超额自由能混合规则．该混合规则考虑了混合物分子体积大小差异的影响,通过引入一个经验参数f,减少了计算中自由能项和对数项的双重影响．该混合规则结合PR立方型状态方程及NRTL活度系数模型,对16种非极性体系、非极性-极性体系、极性与极性体系的汽液相平衡数据进行了关联,与实验数据显示了良好的一致性．与原WS混合规则相比,精度有了一定的提高,且该混合规则只包括活度系数模型参数．A new excess free energy mixing rule based on the infinite-pressure as reference state is proposed in this paper from the correlations of thermodynamics. The size difference of molecules is considered and a parameter f is introduced to reduce the double effect of the free energy term and logarithmic term of the size difference in the calculation. The mixing rule, coupled with PR equation of state and NRTL, leads to the successful correlation of 16 kinds of vapor-liquid equilibria of non polar- nonpolar, nonpolar-polar/ polar - nonpolar and polar-polar systems within a wide range of temperatures and pressures. Compared with the Wong-Sandler mixing rule, the new mixing rule gives better accuracy and only activity coefficient model parameters are needed.

关 键 词：汽液相平衡 状态方程 活度系数 混合规则 

分 类 号：O624.4[理学—有机化学] TQ013.1[理学—化学]