甲烷/氧气预混火焰中燃空当量比对碳烟微观结构和氧化活性的影响  

Effect of Equivalence Ratio on the Microstructure and Oxidation Reactivity of Soot from Premixed Methane/Oxygen Flame

作　　者：李娜[1] 宋崇林[1] 刘野[1] 吕刚[1] Li Na,Song Chonglin,Liu Ye,Lü Gang(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,Chin)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2018年第3期281-287,共7页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB228502);天津市应用基础与前沿技术研究计划资助项目(13JCZDJC35800)

摘　　要：基于甲烷/氧气预混火焰燃烧系统及毛细管取样装置和热泳取样装置,结合高分辨率透射电子显微镜(HRTEM)、拉曼光谱仪(RS)及热重分析仪(TGA),研究了燃空当量比对碳烟的微观结构及氧化活性的影响规律,并对微晶长度、石墨化程度与表观活化能之间的关联性进行了分析.结果表明:随着燃空当量比的增大,碳烟颗粒的微晶尺寸增大,而微晶曲率和层间距均减小,AG/AD1的值增大,表明随着燃空当量比的增大,碳烟的微观结构变得更加有序,石墨化程度更高;碳烟的氧化特征温度和表观活化能均随着燃空当量比增大而增大,表明碳烟的氧化活性随着燃空当量比增大而降低;碳烟的微晶长度、石墨化程度与表观活化能呈现较好的线性关系,碳烟的微观结构越有序,石墨化程度越高,氧化活性越低.The effect of equivalence ratio on the microstructure and oxidation reactivity of soot and the correlations between the fringe length,graphitization and apparent activation energies of soot were studied in this paper. Experiments were conducted in a burner-stabilized methane/oxygen premixed flame,and capillary sampling apparatus and thermophoretic sampling apparatus were used to extract soot samples for subsequent analysis,including high resolution transmission electron microscopy（HRTEM）,Raman spectrum（RS）and thermogravimetric analysis（TGA）.The HRTEM results reveal that as the equivalence ratio increases,the fringe length increases while the separation distance and tortuosity decrease.The value of AG/AD1 determined by RS also increases with the equivalence ratio,indicating that higher equivalence ratio contributes to more ordered and graphitic microstructure; the results from TGA show that the oxidation characteristic temperatures and apparent activation energies also rise with the equivalence ratio,namely,the oxidation reactivity of soot from higher equivalence ratio flame is relatively lower.There is a good linear relationship between the fringe length,graphitization and apparent activation energies of soot,and more ordered and graphitic microstructure of soot would weaken its oxidation reactivity.

关 键 词：碳烟 甲烷/氧气预混火焰 燃空当量比 微观结构 氧化活性 

分 类 号：TF055[冶金工程—冶金物理化学]