氨/甲苯层流扩散火焰中碳烟形态及纳观结构演变的实验研究  

Soot Morphology and Nanostructure Evolution in Ammonia/Toluene Laminar Diffusion Flames

作　　者：余荣浩 徐义书[1] 张凯 成晓北[1] 权燕红[2] Yu Ronghao;Xu Yishu;Zhang Kai;Cheng Xiaobei;Quan Yanhong(School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]华中科技大学能源与动力工程学院,武汉430074 [2]太原理工大学省部共建煤基能源清洁高效利用国家重点实验室,太原030024

出　　处：《燃烧科学与技术》2025年第2期221-233,共13页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(52476116);高技术船舶科研资助项目“奥托循环氨燃料发动机燃烧关键技术研究”;省部共建煤基能源清洁高效利用国家重点实验室开放课题资助项目(MINYSKL202303).

摘　　要：芳香烃是汽、柴油的重要组成部分,也是碳烟生成的重要前驱体.选取甲苯表征芳香烃类组分,通过热泳取样、透射电子显微镜(TEM)观察及图像数据提取方法探究了氨/甲苯层流扩散火焰中碳烟形态、纳观结构的演变规律.结果表明,掺氨降低了火焰上游温度,延长了甲苯燃料裂解所需时间,延缓了碳烟的成核、生长过程,初级颗粒平均粒径减小.但同时,掺氨提高了火焰峰值温度,形成团聚颗粒所需的过程被缩短.掺氨比例达40%时,峰值平均颗粒粒径减小9.87%.此外,掺氨缩短了碳烟的微晶长度、增大了微晶曲率以及层间距,纳观结构变得更加无序,碳烟氧化的可能性增加.对比脂肪烃燃料,甲苯火焰中的峰值平均颗粒粒径最大,掺氨后降幅最低.每掺混1%氨气,甲苯火焰中峰值颗粒粒径的降幅仅为0.2%~0.3%,远低于正癸烷和正庚烷的0.6%和0.9%.芳香烃燃料形成多环芳烃(PAH)的路径更短,碳烟生成倾向更大,掺氨对于芳香烃火焰中碳烟生成的抑制作用小于脂肪烃燃料.Aromatic hydrocarbons are important components of gasoline and diesel fuel,as well as important precursors for soot formation.Toluene was selected to characterize the aromatic hydrocarbons,and the evolution of soot morphology and nanostructure in ammonia/toluene laminar diffusion flame was investigated by thermopho-retic sampling,transmission electron microscope(TEM)observation and image data extraction methods.Results show that ammonia addition reduces upstream flame temperature,prolongs toluene cracking time,slows down soot nucleation and growth process,and reduces the average particle size.However,ammonia addition increases the peak flame temperature,and aggregate formation process is shortened.When the ammonia doping ratio reaches 40%,peak average particle size decreases by only 9.87%.In addition,ammonia addition shortens fringe length,increases tortuosity and inter fringe spacing,indicates that nanostructure becomes more disordered and the possibility of soot oxidation increases.Compared with aliphatic hydrocarbons,peak average particle size in the flame of toluene is the largest,and the decrease is the lowest after ammonia addition.For every 1%of ammonia blended,peak particle size in the toluene flame decreases by only about 0.2%to 0.3%,which is lower than that of n-decane and n-heptane(0.6%and 0.9%).Aromatic fuels have a shorter path to form polycyclic aromatic hydrocar-bons(PAH)and a greater tendency to generate soot,and ammonia addition has a lesser inhibitory effect on soot formation in aromatic flames than in aliphatic fuels.

关 键 词：甲苯 氨 层流扩散火焰 碳烟 结构演变 

分 类 号：TK16[动力工程及工程热物理—热能工程]