摘要柴油机尾气的颗粒会对环境和人类健康造成危害，目前柴油机颗粒捕集器(DPF) 是控制柴油机微粒排放最有效的方法。然而，为了满足日益严格的排放法规,减少大 气污染，DPF 技术还需要改善和优化。在本文中，为了模拟 DPF 流场、碳烟捕集和 再生，我们利用 Fluent 仿真软件建立了二维和三维模型,结果表明:84104

（1）DPF 过滤体内气流运动是层流，且分布均匀，这有利于过滤体的再生。气 体流入过滤体时，过滤体径向中心区域的速度大于边缘地区速度，所以碳烟分布在中 间区域比边缘区域要多；轴向是前段速度大于后段速度,由于受到过滤体内进出口孔 道之间气体流动的影响，在轴向碳烟分布则是中间少两端多。

（2）反应主要发生在碳烟层，并前段反应速率最小，后段反应速率最大。在高 温气体进入 DPF 内后，轴向温度是以逐渐上升的形式分布着，主要影响因素为：碳 烟分布情况、气体流动带动热量流动和温度上升加快反应速率产生热量。

毕业论文关键词： 柴油机颗粒捕集器；碳烟捕集；碳烟再生；仿真模拟

Abstract The particulate of the Diesel exhaust will cause harm to the environment and human health。Currently diesel particulate filter (DPF) is the most effective method to control the particulate emission of diesel engine。 DPF technology also needs to improve and optimize in order to meet the increasingly stringent emission regulations and reduce the pollution of the atmosphere。 We built a 2D and 3D model using Fluent simulation software in order to simulate capture and regeneration of soot。 Results show:

The flow of air in the DPF body is laminar flow, and evenly  distributed。It  is conducive to the regeneration of the filter。Eddy current is an important factor to determine the distribution of flow field。When the exhaust gas flows into the filter,In the radial,central region of the filter is faster than the edge area, so the smoke particles are distributed in the middle area than the edge area。In the axial。the front speed is greater than the rear。Due to the effect of gas flow in the inlet and outlet channels of the filter, the distribution of axial carbon smoke is less than two ends。

The reaction mainly occurred in the carbon smoke layer。When the high temperature gas into the DPF。the axial temperature is distributed in the form of gradually increasing。The main influencing factors were as follows: the distribution of carbon smoke, gas flow led to heat flow and temperature rise to speed up the reaction rate。

Keywords: DPF; soot capture; Soot particulate regeneration; Simulation

目 录

第一章 绪论 1

1。1 引言 1

1。2 柴油机颗粒捕集器及其再生 3

1。2。1 柴油机颗粒捕集器 3

1。2。2 柴油机颗粒捕集器再生及其再生方法 5

1。3 DPF 碳烟捕集与再生仿真研究现状 5

1。4 本文的主要研究内容 6

第二章 DPF 过滤体内的碳烟捕集模拟 7

2。1 干净 DPF 过滤体内的流场 7

2。1。1 DPF 三维模型的建立 7

2。1。2 过滤体内的流场的模拟 13

2。1。3 过滤体内的流场的模拟结果分析