摘要
采用热泳取样技术获取了甲烷/空气扩散火焰中不同高度的碳烟颗粒,并通过原子力显微镜研究了碳烟颗粒的三维形貌随火焰高度变化的演变规律.研究所选高度下碳烟微粒的三维形貌反映出了碳烟微粒在扩散火焰中形成的各个过程,即成核、表面生长、团聚和氧化.当火焰高度HAB从30,mm增加到45,mm时,单碳烟粒子平均粒径从8.72,nm增加到11.36,nm;当HAB〉45,nm时,单碳烟粒子平均粒径逐渐降低;单碳烟粒子的球度比主要分布在0.01-0.30之间,表明这些碳烟粒子的碳化程度较低,呈类液态;球度比随着颗粒体积当量直径的增加而增加,且随着HAB的增加球度比随体积当量直径的增加速率变快,说明单碳烟粒子碳化程度与颗粒大小和火焰高度相关.
The evolution of morphology of the soot particles formed in methane/air flame was investigated by atomic force microscopy.The soot particles at different height above the burner（HAB）were obtained by thermophoretic sam-pling technique.The morphology of thosesoot particles reflected the processes of soot formation including nucleation,coalescence,surface growth,agglomeration and oxidation.With the increase ofHAB from 30,mm to 45,mm,the averaged equivalent volume diameterof single soot particles gradually increases from 8.72 nm to 11.36 nm.Then,averaged equivalent volume diameter decreases to 9.41 nm in the subsequent combustion.Single soot particles spread out on the mica substrate and possess a low sphericity ratiowithin the range of 0.01—0.30, indicating that those soot particles are liquid-like and far from being fully carbonized.Sphericity ratio increases with the increase of equivalent volume diameter,especially at higherHAB,which suggeststhat particle carbonization degree is related to particle size and the height above burner.
作者
王思文
宋崇林
陈男
吕刚
宋金瓯
汪晓伟
高俊华
Wang Siwen Song Chonglin Chen Nan Lu Gang Song Jin＇ou Wang Xiaowei Gao Junhua(State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China China Automotive Technology and Research Center, Tianjin 300162, China)
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2016年第4期364-369,共6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)
国家自然科学基金资助项目(51476115)
关键词
碳烟粒子
甲烷/空气扩散火焰
形貌
原子力显微镜
体积当量直径
球度比
soot particle
methane/air diffusion flame
morphology
atomic force microscopy
equivalent volume diameter
sphericity ratio
