缔合流体在高温高压下的自扩散系数研究

STUDY ON SELF-DIFFUSION COEFFICIENTS OF ASSOCIATING FLUIDS AT HIGH TEMPERATURES AND PRESSURE S

在统计力学理论基础上，本文提出了一个考虑氢键对自扩散系数影响的方程．这个方程为非氢键贡献部分与氢键贡献部分之积，其中自扩散系数的非氢键部分由Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ链模型求得，而一个分子中的平均氢键数随温度和密度的变化关系使用统计缔合流体理论得到。链节之间的相互作用能量参数由粘度的关联式获得，其它四个参数则由扩散系数的实验数据获得。对７个典型的缔合流体在相当宽的温度压力范围内计算的平均相对百分误差为５．９８％。

Based on the statistical mechanical theory, an equation considering the effect of hydrogen- bond on the self-diffusion coefficient was developed. The equation was expressed as a product of a non- hydrogen-bond contribution and a hydrogen-bond contribution. The self-division coefficient from non- hydrogen-bond contribution was calculated using the Lennard-Jones chain model, and the density and temperature dependence of an average number of hydrogen bonds in a molecule was obtained using the statistical associating fluid theory. The segment-segment interaction energy parameter was obtained from the viscosity correlation, and the other four parameters were determined from the experimental diffusion data. The equation developed gives total average absolute deviation with 5.98% for seven typical associating fluids studied over wide ranges of temperature and pressure.