论文部分内容阅读
流体的热力学性质数据对化工过程设计具有重要意义,除实验测定外,也可采用分子模拟方法计算。为了考查分子模拟方法预测流体热力学性质的准确性和可靠性,本文以环氧乙烷为例,基于所开发的分子力学力场,综合采用分子动力学和蒙特卡罗等多种分子模拟方法,预测了环氧乙烷在较大温度范围内的气液相平衡、第二维里系数、热容、粘度系数等多种热力学性质。结果表明,采用分子模拟方法所预测的热力学性质与实验值吻合良好,所计算的环氧乙烷的液体密度、气相第二维里系数、热容和粘度系数的平均偏差分别在1%、5%、5%和10%以内。由此可见,分子模拟方法可以成为获取流体热力学性质的另1种可靠手段。
Thermodynamic properties of the fluid data on the chemical process design is of great significance, in addition to the experimental determination, but also the molecular simulation method can be used. In order to investigate the accuracy and reliability of the molecular simulation method to predict the thermodynamic properties of the fluid, this paper, taking ethylene oxide as an example, based on the developed molecular mechanics force field, combined with molecular dynamics and Monte Carlo methods, The thermodynamic properties of ethylene oxide, such as gas-liquid equilibrium, second-dimension coefficient, heat capacity, viscosity coefficient and so on, were predicted in a large temperature range. The results show that the thermodynamic properties predicted by molecular simulation are in good agreement with the experimental data. The average deviations of the liquid density, the second virial coefficient of gas phase, the heat capacity and the viscosity coefficient of ethylene oxide are respectively 1%, 5 %, 5% and 10%. Thus, the molecular simulation method can be another reliable means of obtaining the thermodynamic properties of fluids.