Effects of ash composition and ash stack heights on soot deposition and oxidation processes in catalytic diesel particulate filter
Effects of ash composition and ash stack heights on soot deposition and oxidation processes in catalytic diesel particulate filter
复制标题
灰分成分和灰堆高度对催化柴油机颗粒过滤器碳烟沉积和氧化过程的影响
DOI：
10.1016/j.joei.2020.04.009
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发表时间：
2020-10-01
影响因子：
5.7
通讯作者：
Zhang, Zhilin
中科院分区：
文献类型：
--
作者：
Fang, Jia;Zhang, Qian;Zhang, Zhilin
为了给柴油机微粒催化过滤器（CDPF）的再生策略和固体催化反应提供理论依据，研究了灰组成和灰堆高度对CDPF中碳烟沉积和氧化过程的影响。通过一系列热重实验，发现MgO灰纳米粒子对碳烟氧化过程具有惰性作用。基于可视化单通道试验台，研究了灰堆高度对灰沉积和再生过程的影响。将碳烟颗粒在无灰CDPF片上的沉积过程分为三个阶段，即深度过滤阶段、过渡过滤阶段和碳烟饼形成阶段。当灰堆高度为15 μ m时，仅存在过渡过滤和烟饼形成阶段。然后，当高度增加到30 μ m时，只剩下烟灰饼形成阶段。在再生过程中，压力降主要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。当灰堆高度从0增加到30 μ m时，再生阶段的碳烟层氧化速率从1.78 Pa/s降低到0.51 Pa/s。在30 μ m灰堆高度处的氧化速率为0.51帕尔斯，这接近于清洁DPF样品的0.55帕尔斯氧化速率。因此，30 μ m左右的灰堆高度是活性氧分子反向扩散的极限距离，这导致CDPF催化层失效。(C)2020能源研究所由爱思唯尔有限公司出版。保留所有权利。
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 mu m, there are only transitional filtration and soot cake formation stages. Then, only soot cake formation stage remains when the height increases to 30 mu m. 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 um, 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 Pals at 30 mu m ash stack height, which is close to the 0.55 Pals oxidation rate of the clean DPF sample. Consequently, around 30 mu m ash stack height is the limit distance of back-diffusion of active oxygen molecules, which leads to the failure of the CDPF catalytic layer. (C) 2020 Energy Institute. Published by Elsevier Ltd. All rights reserved.