柴油机微粒捕集器技术发展现状

颗粒物是柴油机排气主要污染物之一,微粒捕集器能够将排气中的颗粒物过滤,实现90%以上的净化效率,是国际应对未来机动车排放法规的必然选择。文章通过分析近几年国际的研究成果,阐述了颗粒物的组成以及在微粒捕集器中的燃烧过程,并介绍了微粒捕集器的净化机理、材料技术和再生技术。国际研究表明:(1)颗粒物主要由固体碳、可溶性有机成分和硫酸盐三部分组成,在燃烧过程中,可溶性有机物、官能团、高度结晶碳随着温度升高依次燃烧;(2)壁流式微粒捕集器通过扩散、拦截、重力和惯性四种形式将颗粒物拦截过滤;传统的堇青石、碳化硅材料各有优缺点,可能被新型钛酸铝材料取代;过滤体通过增加入口通道体积的方式增加对颗粒物和灰分的容纳能力;(3)微粒捕集器再生技术种类繁多,被动再生技术由于对燃油硫含量由较高要求,因此主要在国外采用;国内主要应采用主动再生技术,同时使用燃油添加剂进行辅助再生。

Research Review on Diesel Particulate Filter

Particulate matter is one of the main pollutants of diesel exhaust.Diesel particulate filter can filtrate the particulate matter from exhaust,reducing by up to 90%,and will be a solution for mobile vehicle exhaust regulations in the future.By analyzing the latest research progress in these years,this paper expatiates the schematic and combustion process of particulate matter in diesel particulate filter.The filtration mechanism,material development and regeneration technologies are introduced too.The international researches show:(1) particulate matter mainly consists of solids,soluble organic fraction and sulfate;in combustion process,soluble organic fraction,functional groups and higher crystalline carbon begin to combust with the temperature rising;(2) wall-flow diesel particulate filter filtrates particulate matter by diffusion,interception,gravity and inertia;traditional cordierite and SiC material have their own advantages and disadvantages,and might be replaced by Al2O3·TiO;the capacity of diesel particulate filter for ash and particulate matter is enlarged by increasing the volume of inlet channels.(3) kinds of regeneration technologies are developed for diesel particulate filter,passive technologies,requiring low-sulfur fuel,are mainly applied in developed countries;active regeneration technologies,by assistant of fuel borne catalyst,should be applied in China.