非对称烷烃体系气液相平衡预测模型的改进

发布时间：2018-10-05 15:14

【摘要】：针对高度非对称烷烃体系,对EOS-G~E气液相平衡预测模型加以改进,其中,状态方程采用考虑体积平移参数的PR-EOS,G~E通过UNIFAC溶液模型计算。针对基团贡献法中假设"溶液中所有基团各向同性"的不足,采用体积参数非线性加和的方式对UNIFAC模型中组合活度系数加以改进。通过对比原始UNIFAC模型和改进UNIFAC模型的预测误差发现,当体系中轻组分含量较低时,原始UNIFAC模型和改进UNIFAC模型对体系泡点预测精度相当;当体系中轻组分含量较高时,原始UNIFAC模型泡点预测值远远低于实验值,而改进UNIFAC模型泡点预测值与实验值高度吻合。模型的改进不仅提高了非对称烷烃体系气液相平衡的预测精度,而且拓展了EOS-G~E模型的应用范围。
[Abstract]:For highly asymmetric alkane systems, the EOS-G~E gas-liquid equilibrium prediction model is improved, in which the equation of state is calculated by UNIFAC solution model using PR-EOS,G~E with consideration of volume translation parameters. In view of the deficiency of the group contribution method which assumes "isotropy of all groups in solution", the combined activity coefficient in the UNIFAC model is improved by means of nonlinear summation of volume parameters. By comparing the prediction error between the original UNIFAC model and the improved UNIFAC model, it is found that the prediction accuracy of the original UNIFAC model and the modified UNIFAC model for the bubble point of the system is similar when the content of the light component in the system is low, and when the content of the light component in the system is higher, the prediction accuracy of the original UNIFAC model and the modified UNIFAC model is similar. The predicted value of bubble point of the original UNIFAC model is far lower than the experimental value, while the predicted value of the improved UNIFAC model is in good agreement with the experimental value. The improved model not only improves the prediction accuracy of gas-liquid equilibrium in asymmetric alkane system, but also extends the application range of EOS-G~E model.
【作者单位】：中国石油大学(北京)/油气管道输送安全国家工程实验室;中石化石油工程设计有限公司管道工程设计所;
【基金】：国家重大专项“海上管道降凝输送及流动管理技术研究”,2016ZX05028-004-001 国家自然科学基金“含蜡原油常温输送机理及流动性方法研究”,51534007
【分类号】：O642.42

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