摘要
开展了柴油机氧化催化器(DOC)和金属DPF对柴油机排气中碳烟纳观结构特性的影响研究。结果表明:原机排气中碳烟平均微晶长度(L_(p))随负荷的增加而增大,随转速的升高而减小;平均微晶层间距(D_(p))和平均微晶曲率(T_(p))的变化规律与L_(p)相反。经过DOC处理后,L_(p)增大,D_(p)和T_(p)减小;而它们的变化幅度均随负荷的增大而增大,随转速的升高而减小。金属DPF对碳烟3个纳观结构特性参数的影响均不大。原机排气中碳烟的L_(p)、D_(p)和T_(p)均与碳烟氧化反应表观活化能(E_(a))具有密切的相关性,其中,T_(p)与E_(a)的决定系数最大;经过DOC处理后,L_(p)、D_(p)和T_(p)与E_(a)的决定系数均略有增加。
This study investigated the effects of Diesel Oxidation Catalyst(DOC)and metal-based Diesel Particulate Filter(DPF)on the nanostructure of diesel exhaust soot.The results show that the raw soot that sampled at the pre-DOC site tends to exhibit larger average fringe length(L_(p))at high engine load,while the values of L_(p)becomes smaller with the increased engine speed.However,the values of average separation distance(D_(p))and average tortuosity(T_(p))show opposite trends as compared with the the L_(p)when varying the engine operating condition.The DOC treatment increases the L_(p)value and simultaneously decreases the values of D_(p)and T_(p),all of which exhibit more significant variations at the higher engine load while exhibit smaller variations at higher engine speed.The DPF treatment has negligible effect on the soot nanostructure,as evidenced by the smaller variations in L_(p),D_(p)and T_(p)when comparing the soot samples pre-and post-DPF.The soot oxidation reactivity apparent activity energy(E_(a))possesses excellent correlations with the values of L_(p),D_(p)and T_(p).Specifically,the T_(p)value shows the strongest correlation with E_(a).The DOC treatment improves the correlations between the soot oxidation reactivity and nanostructure because the determination coefficients of the L_(p),D_(p)and T_(p)against E_(a)increase after DOC treatment.
作者
李明
郝斌
LI Ming;HAO Bin(Tianjin Academy of Educational Science,Tianjin,300191,China;Yutong Bus Company Limited)
出处
《小型内燃机与车辆技术》
CAS
2024年第1期40-45,共6页
Small Internal Combustion Engine and Vehicle Technique
关键词
柴油机氧化催化器
柴油机微粒捕集器
碳烟
纳观结构
氧化活性
Diesel Oxidation Catalyst(DOC)
Diesel Particulate Filter(DPF)
Soot
Nanostructure
Oxidative Activity
