In order to provide the theorical basis for regeneration strategy and solid catalytic reaction of catalytic diesel particulate filter (CDPF), the effects of ash composition and ash stack heights on soot deposition and oxidation processes in CDPF are investigated. The MgO ash nanoparticles have an inert effect on soot oxidation process through a series of thermogravimetric experiments. Based on the visualized single-channel bench, the influence of ash stack height on the soot deposition and regeneration processes is studied. The deposition process of soot particles on the CDPF slice without ash is divided into three stages, including depth filtration, transitional filtration and soot cake formation stages. When the ash stack height is 15 μm, there are only transitional filtration and soot cake formation stages. Then, only soot cake formation stage remains when the height increases to 30 μm. During the regeneration process, the pressure drop mainly has three linear decline stages, the oxidation rates of which are 0.77, 1.78 and 0.54 Pa/s, respectively. When the ash stack height increases from 0 to 30 μm, the oxidation rate of soot layer during Ⅱ-regeneration stage decreases from 1.78 to 0.51 Pa/s. The oxidation rate is 0.51 Pa/s at 30 μm ash stack height, which is close to the 0.55 Pa/s oxidation rate of the clean DPF sample. Consequently, around 30 μm ash stack height is the limit distance of back-diffusion of active oxygen molecules, which leads to the failure of the CDPF catalytic layer.

为了为催化柴油颗粒过滤器（CDPF）的再生策略和固体催化反应提供理论依据，研究了灰分组成和烟灰堆高对CDPF中烟灰沉积和氧化过程的影响。MgO灰分纳米颗粒通过一系列热重实验对烟灰氧化过程具有惰性作用。基于可视化的单通道工作台，研究了烟灰堆高度对烟灰沉积和再生过程的影响。烟灰颗粒在没有灰分的CDPF切片上的沉积过程分为三个阶段，包括深度过滤，过渡过滤和烟灰饼形成阶段。当烟灰堆高度为15μm时，只有过渡过滤和烟灰饼形成阶段。然后，当高度增加到30μm时，仅剩下烟灰饼形成阶段。在再生过程中，压降主要具有三个线性下降阶段，其氧化速率分别为0.77、1.78和0.54 Pa / s。当烟灰堆高度从0增加到30μm时，Ⅱ再生阶段烟灰层的氧化速率从1.78降至0.51 Pa / s。在灰堆高度为30μm时，氧化速率为0.51 Pa / s，接近清洁DPF样品的0.55 Pa / s氧化速率。因此，约30μm的烟灰堆高度是活性氧分子向后扩散的极限距离，这导致CDPF催化层失效。分别为1.78和0.54 Pa / s。当烟灰堆高度从0增加到30μm时，Ⅱ再生阶段烟灰层的氧化速率从1.78降低到0.51 Pa / s。在灰堆高度为30μm时，氧化速率为0.51 Pa / s，接近清洁DPF样品的0.55 Pa / s氧化速率。因此，约30μm的烟灰堆高度是活性氧分子向后扩散的极限距离，这导致CDPF催化层失效。分别为1.78和0.54 Pa / s。当烟灰堆高度从0增加到30μm时，Ⅱ再生阶段烟灰层的氧化速率从1.78降至0.51 Pa / s。在烟灰堆高度为30μm时，氧化速率为0.51 Pa / s，接近清洁DPF样品的0.55 Pa / s氧化速率。因此，约30μm的烟灰堆高度是活性氧分子向后扩散的极限距离，这导致CDPF催化层失效。