DOC和金属滤芯DPF对柴油机排气碳烟石墨化程度及氧化活性的影响  

Effect of DOC and Metal-based DPF on the Graphitization Degree and Oxidation Reactivity of Diesel Exhaust Soot

作　　者：郝斌 张华伟 张清茂 杨振中[2] 王丽君[2] Hao Bin;Zhang Huawei;Zhang Qingmao;Yang Zhenzhong;Wang Lijun(Zhengzhou Yutong Bus Co.,Ltd.,Zhengzhou,Henan,450016,China;North China University of Water Resources and Electric Power;Geely Automobile Research Institute)

机构地区：[1]郑州宇通客车股份有限公司,河南郑州450016 [2]华北水利水电大学 [3]吉利汽车研究院(宁波)有限公司

出　　处：《小型内燃机与车辆技术》2020年第5期50-56,共7页Small Internal Combustion Engine and Vehicle Technique

基　　金：河南省高等学校重点科研项目(20A470008);河南省科技攻关(182102311019);河南省高校科技创新团队支持计划资助(19IRTSTHN011)。

摘　　要：开展DOC和金属滤芯DPF对柴油机排气碳烟石墨化程度和氧化活性影响规律的研究,并分析了石墨化程度与氧化活性的相关性。结果表明:柴油机排气碳烟中2种方法所获得石墨化程度(AG/AD1和R值)及氧化反应表观活化能(Ea)分别处于0.205~0.293、0.094~0.136及138.9~168.1 k J/mol之间;原机排放碳烟的AG/AD1、R值和Ea均随转速的升高而下降,随负荷的升高而提高;DOC处理后碳烟的AG/AD1、R值和Ea显著提高,且涨幅也基本上随转速的升高而下降,随负荷的升高而提高;多数工况下,金属滤芯DPF对AG/AD1、R值及Ea的影响极小;DOC处理前、后碳烟中AG/AD1或R值与Ea有一定相关性,且Ea对AG/AD1更敏感;DOC能够改善Ea与AG/AD1的相关性,但对Ea与R值的相关性影响不大。This study investigated the effect of the commercial diesel oxidation catalyst(DOC)and the metal-based diesel particulate filter(DPF)on the graphitization degree and oxidation reactivity of diesel exhaust soot under different engine operating conditions.In addition,the correlations between the graphitization degree and the oxidation reactivity were also examined.The obtained results show that the values of AG/AD1,Iπ*/Iσ*and the apparent activation energy(Ea)of diesel exhaust soot were in the ranges of0.205-0.293,0.094-0.136 and 138.9-168.1 kJ/mol,respectively.The raw(pre-DOC)soot exhibits decreases in AG/AD1,Iπ*/Iσ*and Eawith the increased engine speed,while the increase in engine load produces the raw soot with higher values of AG/AD1,Iπ*/Iσ*and Ea.The DOC treatment increases the values of AG/AD1,Iπ*/Iσ*and Eaunder various engine operating conditions.Note that,the increments become smallerat higher engine speed,while the increments become larger with increased engine load.However,the DPF treatment has little effect on the variations of the AG/AD1,Iπ*/Iσ*and Eavalues at almost all the conditions.The AG/AD1 and Iπ*/Iσ*for both the pre-DOC and post-DOC soot show strong correlations with the Ea,suggesting a definite correlation between the graphitization degree and oxidation reactivity of diesel exhaust soot.In addition,the DOC treatment promotes the correlation between the AG/AD1 and Ea,while it exerts negligible effect on the correlation between the Iπ*/Iσ*and Ea.

关 键 词：柴油机氧化催化器 柴油机微粒捕集器 金属滤芯 碳烟 石墨化程度 表观活化能 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]