碳烟颗粒生长演变历程环境因素的影响

Influence of Environmental Factors on Soot Dynamics Evolution

基于颗粒群平衡方程和包含有多环芳香烃分子生成的详细化学反应机理,构建了详细的碳烟生长数学模型,模型包含颗粒的成核、凝聚、表面生长和氧化等过程;采用Lagrange内插值的矩方法,导出了颗粒尺寸分布函数各阶矩的微分方程;与均匀搅拌器燃烧模型相耦合,应用Fortran语言编程,搭建了碳烟颗粒动力学演变历程的计算平台.探讨了温度、压力和燃空当量比等环境因素对碳烟颗粒生长演变历程的影响,计算结果表明:碳烟颗粒的数密度在某一温度下达到峰值,在温度相对较低、当量比和压力相对较高的环境下,碳烟的生成质量也较大;碳烟颗粒的最终质量是颗粒生长与氧化共同作用的结果.

A detailed mathematical model of soot growth process was built on the basis of population balance theory and detailed chemical reaction mechanism containing PAH molecules generated, including particle nucleation, condensation, surface growth and oxidation processes. Lagrange interpolation method of moments was used to derive the moments of differential equations of particle size distribution function. This model coupled with the perfect stirred reaction model built a soot particle dynamics evolution computational platform using the Fortran language. The effects of temperature, pressure and fuel-air equivalence ratio on the growth of soot particles evolution were discussed. Re- suits show that the number density of soot reaches a peak at a certain temperature. Soot quality is also larger at lower temperatures, higher pressure and equivalence ratio. The final quality of soot particle is the results of oxidation and surface growth.