DPFの初期PM捕集性能に対する表面粗さの影響(熱工学,内燃機関,動力など)

抄録

In recent years, environmental regulation tends to become strict rapidly, and the further highly performance of DPF is demanded, which mainly consists of surface filtration and depth filtration. Generally, if the wall thickness is thin, the soot in diesel exhaust gas may break through and leak the filter, because the depth filtration doesn't work enough. However, most of filtration efficiency depends on surface filtration, because the soot cake forms on the surface of ceramic filter, and the soot cake takes part in highly performance of the filter. Therefore, the most important thing is how to make the soot cake rapidly. In this study, we pay attention to the surface roughness of ceramic filter. We observed the micro-porous structure of the filter based on SEM images. Also, we measured soot diameter and particle number concentration using different filters. Results show that, when too big open and too deep pore exist on the filter surface, the soot leakage occurs easily. In this case, it's hard to make soot layer rapidly and the soot leaks during initial DPF usage. Once the soot layer is formed, the filtration efficiency becomes high, and small particulates called SPM are caught effectively. Thus, it is important to control surface roughness for making soot layer rapidly.