NO2-O2气氛下柴油机碳烟氧化特性及氧化机理  

Oxidation Characteristics and Mechanisms of Diesel Soot in NO2-O2 Atmosphere

作　　者：宁创 宋崇林[1] 吕刚[1] 高继东[2] 刘双喜[2] 乔约翰 Ning Chuang;Song Chonglin;LüGang;Gao Jidong;Liu Shuangxi;Qiao Yuehan(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;National Engineering Laboratory of Mobile Source Pollution Control Technology,China Automotive Technology and Research Center Co.,Ltd,Tianjin 300300,China)

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 [2]中国汽车技术研究中心有限公司移动源污染排放控制技术国家工程实验室,天津300300

出　　处：《燃烧科学与技术》2020年第5期467-474,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51876142);移动源污染排放控制技术国家工程实验室开放基金资助项目(NELMS2018A15);天津市科技计划资助项目(18PTZWHZ00170)。

摘　　要：通过热重分析仪及无模式函数法研究了柴油机碳烟在O2、NO2-O2气氛下的氧化特性及氧化机理,并探究了NO2对碳烟氧化反应的影响机制.结果表明:在10%O2中添加0.1%NO2降低了柴油机碳烟氧化反应的起燃温度和燃尽温度,并且NO2对上述氧化反应特征温度的影响效果随升温速率(10℃/min、12℃/min、15℃/min)的增加而提高;添加0.1%NO2促进柴油机碳烟氧化反应的进行,显著降低氧化反应本征活化能;柴油机碳烟氧化过程可分成氧化前期、氧化中期及氧化后期3个阶段;随碳烟失重比的增加,碳烟氧化反应有效活化能先增后减再不变,其原因为本征反应和气体扩散作用对氧化速率影响效果的此消彼长;碳烟失重比小于65%时,NO2能够降低碳烟氧化反应有效活化能,碳烟失重比大于等于65%时,NO2对有效活化能的影响逐渐消失.The oxidation characteristics and mechanisms of diesel soot in O2 and NO2-O2 atmospheres were studied respectively by a thermal gravimetric analyzer and the model-free method to explore the effect of NO2 on the oxidation of diesel soot.The results show that the initial oxidation temperature and bunt-out temperature of diesel soot were both reduced by adding 0.1%NO2 to 10%O2,and the effect of NO2 on the initial oxidation temperature and bunt-out temperature increased with the increase of heating rate(10℃/min,12℃/min,and 15℃/min).Adding 0.1%NO2 can promote the oxidation reaction of diesel soot and reduce the intrinsic activation energy of oxidation reaction significantly.The oxidation process of diesel soot can be divided into three stages:early stage,middle stage and late stage.With the increase in the burnout rate of soot,the apparent activation energy increased first,then decreased,and remained unchanged.The reason lay in the variation of the effect of the intrinsic reaction and the gas diffusion on the oxidation rate.When the burnout rate of soot was lower than 65%,NO2 can reduce the apparent activation energy.When the burnout rate of soot was higher than or equal to 65%,the effect of NO2 on the apparent activation energy disappeared.

关 键 词：柴油机碳烟 氧化特性 无模式函数法 氧化机理 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]