高原轻型车用发动机PN排放特性的试验研究

Experimental Study on PN Emission Characteristics of Highland Light Vehicle Engines

基于1900m海拔的发动机试验台架,针对一台国六轻型车用发动机,开展搭载后处理系统的整机PN排放特性的试验研究,分析其在高原下原机PN与尾排PN的变化规律,为高原轻型车后处理系统开发提供数据支持。研究发现:高原汽油机原机PN排放随着车速的升高而不断降低,捕集效率随车速的增加呈先增加后减小的趋势,主要与载体孔隙及是否高温灼烧相关;原机PN排放值对捕集效率的影响较大,尤其是冷启动条件下,受发动机缸内温度低、燃烧不充分等影响较大;为增大颗粒物捕集效率,可为GPF添加(或涂覆)部分不可灼烧的的灰分或其它成分以减小孔径孔隙。

Based on the test-bed at 1900m altitude,an experimental study on PN emission characteristics of a national six light-duty vehicle engine loaded with a post-processing system is carried out,and the variation law of PN emission from plateau engine and tail engine is analyzed,which provides data support for the development of post-processing system of Plateau light vehicle.The results show that the PN emission decreases with the increase of vehicle speed,and the trapping efficiency increases first and then decreases with the increase of vehicle speed.In order to increase the capture efficiency of particulate matter,the eff ect of PN emission on the capture efficiency of the engine is studied,especially under the condition of cold start.The influence of low temperature in the cylinder and insufficient combustion of the engine,and the influence of PN emission on the capture efficiency of the engine is analyzed.Non-combustible ash or other ingredients can be added(or coated)to the GPF to reduce pore size voids.