缸内后喷对CDPF温度特性及再生效率的影响

Effect of cylinder post-injection on CDPF temperature and regeneration efficiency

随着排放法规的日益严格,氧化催化转化器(diesel oxidation catalyst,DOC)+催化型柴油颗粒捕集器(catalyzed diesel particulate filter,CDPF)已经成为降低柴油机排放CO、THC和颗粒物的主流技术,而CDPF再生是目前技术发展的主要阻碍之一,文章研究了再生过程中缸内后喷对DOC、CDPF的影响,得出缸内后喷可以使尾气达到DOC的起始工作温度,而次后喷可以使DOC出口温度达到CDPF的再生温度;试验过程中通过良好地控制CDPF入口再生温度,得到了再生效率的变化规律,在500℃、20min工况下再生效率达到98%,满足再生要求,并且总结了一种标定的试验方法,为后续研究的进行积累了一定的经验。

With the increasingly stringent emission regulations,diesel oxidation catalyst(DOC)+catalyzed diesel particulate filter(CDPF)has become the mainstream technology to reduce the emission of CO,THC and particulates from diesel engines.However,CDPF regeneration is one of the main obstacles to the development of this technology at present.In this paper,the effects of cylinder post-injection regeneration process on DOC and CDPF are studied.It is found that the cylinder post-injection can make the exhaust gas reach the initial working temperature of DOC,and the second post-injection can make the DOC outlet temperature reach CDPF regeneration temperature.During the experiment,the inlet temperature of CDPF is well controlled,and the change law of regeneration efficiency is obtained.Under the conditions of 500℃and 20 min,the regeneration efficiency reaches 98%,which is up to the requirement of regeneration.And a test method of calibration is summarized,which is valuable for future research.