CH4-O2预混火焰中温度对碳烟纳观结构及形貌的影响
Effect of Temperature on Soot Nanostructure and Morphology in CH4-O2 Premixed Flames
宋崇林 1洪亮 1汪晓伟 1李政 1陈男 1张仲荣2
作者信息
- 1. 天津大学内燃机燃烧学国家重点实验室,天津300072
- 2. 中国汽车技术研究中心,天津300162
- 折叠
摘要
采用热泳取样、高分辨率透射电镜和原子力显微镜,研究了CH4-O2预混火焰中火焰温度对碳烟颗粒纳观结构的影响规律.结果表明,低温火焰中生成的碳烟颗粒的微晶长度短,微晶片层杂乱无序,没有明确的中心,而高温火焰生成的碳烟颗粒的微晶片层明显增大,微晶尺寸变长,边缘更为清晰,有明显的同心片层组织结构.基本粒子平均粒径都随火焰高度(height above burner,HAB)的增加而增加,而随着火焰温度升高而减小.初生碳烟颗粒呈扁平状,随着HAB增加,碳烟颗粒由于生长渐趋成熟,并呈现为球形或椭球形,基本粒子粒径分布变宽且出现双峰分布.
Abstract
Soot particles formed in premixed methane-oxygen flames at the same C/O ratio were sampled on TEM grids and AFM (atomic force microscopy) substrates by thermophoretic sampling method,and the size distribution,morphological characterization and nanostructure of the nanoparticles are measured by HRTEM (high resolution transmission electron microscopy) and AFM.Results show that the nanoparticles formed in low temperature flames are of short and disordered lattice fringes,while those formed in high temperature flames show obvious concentric organization or shell/core structure and are of longer and well-organized fringes.The size of primary particles decreases as flame temperature increases,but increases as HAB (height above burner) increases.AFM probing of the same particles shows that the nascent soot particles detected at 5 mm above the burner are extremely flattened in form and with a narrow size distribution,and with the increase of HAB,they grow and the size distribution gets broadened.
关键词
CH4-O2预混火焰/温度/碳烟颗粒/纳观结构/形貌Key words
CH4-O2 premixed flame/temperature/soot particles/nanostructure/morphology引用本文复制引用
出版年
2013
NETL
NSTL
维普
万方数据