不同压力下层流对冲C2H4扩散火焰中碳烟生成的数值模拟研究  

Numerical Simulation of Soot Formation in Laminar C2H4 Opposed-flow Diffusion Flames under Different Pressures

作　　者：王生福 席剑飞[1] 顾中铸[1] 蔡杰[1] Wang Shengfu;Xi Jianfei;Gu Zhongzhu;Cai Jie(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学能源与机械工程学院,江苏南京210023

出　　处：《南京师范大学学报（工程技术版）》2020年第4期16-21,共6页Journal of Nanjing Normal University(Engineering and Technology Edition)

基　　金：国家自然科学基金资助项目(51706107、51878356);江苏省自然科学基金面上项目(BK20181385).

摘　　要：采用Chemkin中的对冲扩散火焰模型对C2H4对冲扩散火焰中碳烟颗粒的生成进行了数值模拟研究,重点关注不同压力下碳烟颗粒及部分气相小分子和前驱物的形成.以0.1 atm为增量,探讨了1~5 atm内乙烯扩散火焰中多种中间产物和碳烟前驱物的浓度分布.数值模拟结果表明,随着压力的不断增大,碳烟体积分数和碳烟数密度快速增加,H2、CH4等气相小分子的含量总体呈现下降趋势但变化不大,火焰面及气相小分子的生成区域变小.PAHs和C2H2含量的快速增加是通过HACA机理实现的,使得碳烟成核和生长速率加快,从而促进了碳烟数密度和体积分数的迅速增加.The opposed-flow diffusion flame model in Chemkin is used to simulate the formation of soot in C2H4 diffusion flames,focusing on the formation of soot particles and some gas phase small molecules and precursors under different pressures.The concentration distributions of various intermediates and soot precursors in C2H4 diffusion flames are investigated under pressure range of 1 to 5 atm in increments of 0.1 atm.The results show that with the increase of pressure,the volume fraction and number density of soot increase rapidly,the content of H2,CH4 and other small molecules decreases,and the formation area of small molecules in the flame surface and gas phase becomes smaller.The rapid increase of PAHs and C2H2 content is realized by HACA mechanism,which accelerates the nucleation and growth rate of soot,and promotes the rapid increase of soot number density and volume fraction.

关 键 词：高压 碳烟生成 对冲扩散火焰 数值模拟 

分 类 号：TK402[动力工程及工程热物理—动力机械及工程]