关键词: DPF 再生工况；重型商用车；后处理系统；排气系统；温度场；热源；热辐射

Abstract: This paper studies the surrounding thermal field of a China VI heavy diesel commercial vehicle under diesel particulate filter (DPF) regeneration conditions, and proposes reasonable arrangement principles and methods of the heat source surrounding system to further improve the safety and reliability of vehicle operation. Firstly, the whole process of DPF regeneration and the temperature field at different distances are simulated by computational fluid dynamics (CFD). Secondly, the experiment verifies the four stages of DPF active regeneration, the temperature field at different distances and the surface temperature of the peripheral parts under the steady regeneration condition. Finally, the data under different working conditions are compared and analyzed. The results show that during the steady parking regeneration period of DPF, the internal air flow temperature can reach more than 600 ℃, and the highest temperature at the exhaust pipe joint is 235℃. The temperature field presents a nonlinear downward trend with the increase of distance, showing the thermal decay law of the closer to the heat source, the faster the temperature drop, the farther the distance from the heat source, the slower the temperature drop. The distance between the peripheral parts and the heat source is greater than 200 mm and can be reduced to below 80 ℃, which can effectively prevent the heat damage caused by the after-treatment system.

Key words: DPF regenerative conditions; heavy commercial vehicle; after-treatment system; exhaust system; temperature field; heat source; thermal radiation