推广的van der Waals压缩因子及其对超临界流体的应用

Augmented van der Waals Compressibility Factor and its Application to Supercritical Fluids

利用实验测得的液体的热压力系数,修正原始van der Waals模型中的排斥体积,得到了一个适用于高密度流体的推广的van der Waals压缩因子。将它与Redlich和Kwong提出的吸引项相结合,建立了一个流体状态方程。用某些有代表性的超临界流体的pVT数据检验,结果表明,其对体积、压力和逸度系数的计算准确度可与CS-RK方程相媲美。

With the experimental values of thermal pressure coefficients of liquids to modify the excluded volume in the original van der Waals equation, an augmented van der Waals compressibility factor applicable to high density fluids is obtained. The further combination with Redlich-Kwong attraction term forms a new EOS of fluids. The experimental p-V-T values for some typical supercritical fluids are used to examine this new EOS. The calculated results for the pressures, volumes and fugacity coefficients show that the new EOS can compare favourably with the CS-RK EOS.