废气再循环对柴油机颗粒结构特征与氧化活性的影响  

Effect of Exhaust Gas Recirculation on Particle Structure Characteristics and Oxidation Activity of Diesel Engines

作　　者：华琰 王忠[1] 李瑞娜[1,2,3] 刘帅 赵洋[4] 梅德清 吕辉[1] HUA Yan;WANG Zhong;LI Ruina;LIU Shuai;ZHAO Yang;MEI Deqing;LÜ Hui(School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China;Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610000, China;Provincial Engineering Research Center for New Energy Vehicle Intelligent Control and Simulation Test Technology of Sichuan, Xihua University, Chengdu 610000, China;School of Automotive Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China)

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212013 [2]西华大学汽车测控与安全四川省重点实验室,成都610000 [3]西华大学四川省新能源汽车智能控制与仿真测试技术工程研究中心,成都610000 [4]常熟理工学院汽车工程学院,江苏常熟215500

出　　处：《西安交通大学学报》2022年第5期21-30,共10页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51876082);江苏省自然科学基金资助项目(BK20200910);四川省新能源汽车智能控制与仿真测试技术工程研究中心开放课题资助项目(XNYQ2021-003)。

摘　　要：为探究废气再循环(EGR)对柴油机颗粒结构特征与氧化活性的影响规律,采集了不同废气质量分数的F-T柴油、生物柴油和柴油3种燃料的燃烧颗粒,运用粒径谱仪(EEPS)、透射电镜(TEM)、热重分析仪(TGA)等方法,探究了颗粒物的结构特征与氧化活性。结果显示,随着废气质量分数的增加,颗粒物平均粒径、分形维数D_(f)、基本粒子的层面间距d和微晶曲率T_(f)升高,微晶尺寸L_(a)、氧化特征温度和表观活化能E_(a)降低,颗粒物结构更加紧凑,团聚程度增加,碳层有序性减弱,颗粒稳定性变差,氧化活性增强,表明采用EGR技术可降低颗粒捕集器(DPF)的再生温度。废气质量分数相同时,柴油产生的颗粒物平均粒径最大,比F-T柴油升高了3.3%~7.1%;燃用生物柴油的颗粒物基本粒子碳层排列更加无序,氧化反应活性较强;当颗粒基本粒子具有更宽的d、更短的L_(a)和更大的T_(f)时,颗粒氧化活性更强。To discuss the effect of exhaust gas recirculation(EGR)on particle structure characteristics and oxidation activity of diesel engines,the particles produced by the combustion of F-T diesel,biodiesel and common diesel under different exhaust gas mass fractions are collected,and such means as engine exhaust particle sizer(EEPS),transmission electron microscope(TEM)and thermogravimetric analysis(TGA)are used to study their structure characteristics and oxidation activity.The results show that with the increase of mass concentrations,the average particle size,fractal dimension(D_(f)),layer spacing(d)of basic particles and microcrystalline curvature(T_(f))increased,the microcrystalline size(L_(a)),oxidation characteristic temperature and apparent activation energy(E_(a))decreased,and it saw more compact particle structure,increased agglomeration,weakened order of carbon layer,worse particle stability,and enhanced oxidation activity.This indicates that the regeneration temperature of diesel particulate filter(DPF)can be reduced by using EGR technology.Moreover,when the exhaust gas mass fraction was the same,the mean size of common diesel particles was the largest,which was 3.3%-7.1%higher than that of F-T diesel.The particles with biodiesel were more disordered and had strong oxidation activity.When the basic particles have wider d,shorter L_(a) and larger T_(f),the oxidation activity of the particles was stronger.

关 键 词：柴油机 F-T柴油 生物柴油 颗粒物 废气再循环 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]