HCs/HCs和HCs/CO_2二元体系表面张力的预测

Surface Tension Calculation of HCs/HCs and HCs/CO_2 Binary Mixtures Based on the Gradient Theory

表面张力是非常重要的物性之一,本文将比容平移后的PR状态方程和密度梯度理论结合,建立了不依赖于混合物表面张力和气液相平衡实验数据的二元混合物表面张力的纯预测模型。对碳氢/碳氢和碳氢/二氧化碳二元体系的表面张力进行了预测,结果表明,本文模型对两组元碳原子数相差不大或者两组元分子结构满足链状和环状或环状和环状组合的碳氢/碳氢二元体系有较高的预测精度,同时模型对碳氢/二氧化碳二元体系表面张力也有较好的预测能力。

Surface tension is a basic and important thermophysical property for fluids.In this work,a model based on the gradient theory combining with the volume translation Peng-Robinson EOS was established to predict the surface tension of HCs/HCs and HCs/CO_2 binary mixtures,this model is predictive which does not rely on the experimental data of surface tension and vapor-liquid equilibrium of binary mixtures.The calculation results show that present model has good prediction accuracy on two kinds of specific HCs/HCs binary systems,one is mixtures with small difference of carbon atom number,the other one is mixtures with chain/cycle or cycle/cycle molecular structure, and the model can also predict the surface tension of HCs/CO_2 binary systems.