立方扰动硬链方程

本文通过在SPHC方程中引入拟合Carnahan-Starling硬球方程所得的斥力项,建立了立方型扰动硬链状态方程.由拟合正构烷烃的饱和蒸汽压和液相密度所确定的3个纯组分参数与碳原子数呈良好线性关系.对19种纯物质饱和蒸汽压和液相密度数据计算的平均相对误差分别为1.52%和2.97%;对混合物提出了一种新的混合规则,应用于预测含短链和长链烃类及二氧化碳、硫化氢混合物的高压汽液平衡,优于采用SPHC、SRK和PT方程所得的计算结果.

A CUBIC PERTURBED HARD CHAIN EQUATION OF STATE

For extending the complex perturbed hard chain equation of state to practical engineering calculations, a cubic version is proposed.The new equation is formulated by replacing the repulsive term with a simulated Carnahan-Starling hard sphere equation and combining it with the attractive term in the simplified perturbed hard chain equation of state proposed by Kim et al.The three pure component parameters of 14 n-alkanes and carbon dioxide were determined by fitting the saturated vapor pressure and saturated liquid density data simultaneously over wide temperature and pressure ranges. A new mixing rule has been applied to the energy parameter of the proposed simplified perturbed hard chain equation of state and tested on the vapor-liquid equilibrium and pVT calculations of binary mixtures. Comparisons with four existing equations of state (SPHC, SRK, PR and PT) have been performed.