O_2/CO_2气氛下煤种对燃煤PM_(2.5)形成的影响  

Effect of Coal Type on PM_(2.5) Formation in O_2/CO_2 Atmosphere

作　　者：屈成锐[1] 赵长遂[1] 周骛[1] 段伦博[1] 

机构地区：[1]东南大学热能工程研究所,江苏省南京市210096

出　　处：《中国电机工程学报》2011年第2期22-26,共5页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2006CB705806)~~

摘　　要：采用管式炉和荷电低压撞击器(electrical low pressure-impactor,ELPI)研究了4种煤粉在O2/CO2条件下燃烧后生成的PM2.5排放特性,并对空气和O2/CO2气氛下PM2.5的排放特性进行了比较。结果表明:不同煤粉在O2/CO2气氛下燃烧后,所产生的PM2.5质量浓度均呈双峰分布,峰值分别在0.1和2μm左右;S在亚微米颗粒上明显富集,而在超微米颗粒上含量相对较少;K和Na在亚微米颗粒上含量比在超微米颗粒上高一些;Si和Ca在亚微米颗粒上含量相对较少,而在超微米颗粒上含量相对较多;Fe在亚微米和超微米颗粒上含量相当。分析认为,不同煤粉中组分形式和含量的不同,影响了煤粉燃烧后PM2.5形成的过程,造成PM2.5排放特性的不同。从PM2.5的粒径分布、元素分布和形貌分析可知,和空气气氛相比,O2/CO2气氛不影响PM2.5的生成机制,但影响其粒径分布。Four different pulverized coals were burned in a tube furnace under O2/CO2 atmosphere and electrical low pressure-impactor（ELPI）was used to collect the PM2.5 for investigating the emission features of PM2.5.The comparison of PM2.5 emission characteristics was made between O2/CO2 combustion and air combustion.It is shown that a similar bimodal distribution of PM2.5 appeared.The small and large modes were located at 0.1 mm and 2 mm,respectively.S was enriched in submicron-size PM,but its contents were small in supermicron-size PM.The contents of K and Na in the PM1 were higher than those in the PM1-2.5.The contents of Si and Ca were greater in supermicron-size PM,but they were smaller in submicron-size PM.The content of Fe in supermicron-size PM was similar to in submicron-size PM.So it was believed that the different emission features were influenced by the different formation processes resulted from discrepancy of different kinds of coal.Compared with air combustion,O2/CO2 combustion had a significant impact on the size distribution of the submicron ash particles but no affect the mechanism of submicron particle formation based on the analyses of particle size distribution,elements distribution and morphology of PM2.5.

关 键 词：O2/CO2 煤燃烧 PM2.5 形成机制 煤种 

分 类 号：TK16[动力工程及工程热物理—热能工程]