Effects of temperature and flow control on the regeneration process of Diesel Particulate Filter
| Autor: | Yen-Jung Huang, 黃彥榮 |
|---|---|
| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 There is a growing concern for the pollutants emitted by diesel vehicles, especially the World Health Organization (WHO) officially classified diesel engine exhaust as a carcinogen. Countries all over the world have formulated stringent standards to regulate the emissions of new diesel engines. However, diesel engines are very durable that 60% of the diesel vehicles are more than ten years old in Taiwan. In order to reduce the exhaust emission of these in use vehicles, installation of diesel particulate filter (DPF) is currently promoted. As the carbon particulates accumulate inside the filter to a certain amount, the DPF needs to be regenerated to prevent clogging of the filter. Because the regeneration process may burn a hole in the filter. It may also cause “second pollution” and generate hot exhaust that might cause disasters when the regeneration is conducted as the vehicle is parking. The purpose of this study is to establish a model to predict heat transfer and combustion when DPF is regenerating. Assuming the gas flowing in the filter of channel, each points within the channel of temperature are the same. Temperature changes only occur in the porous structure of the wall, so the temperature of the flowing gas will change with wall thickness and the presence of soot. We can use this model to predict the temperature of filter and outlet during the regeneration. A low-cost technology, using a bypass valve system during generation, was proposed in this study as a solution to abate the second pollution and reduce the exhaust temperatures. We also discuss the influence of using different temperature range for regeneration. Different bypass ratios up to 50% were tested in this study. It was found the NOx produced during the regeneration process decreased scarcely. The opacity of the exhaust flue gas was reduced by 30%. The mass concentration of PM2.5 was reduced by 50%. The regeneration efficiency slightly declined, but still within the acceptable range. It is found that temperature controlled below 500℃, the regeneration efficiency will be significantly inferior to other temperatures. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|