NO_2-Assisted Regeneration Performance Enhancement of Catalyzed Diesel Particulate Filters

摘要

Considering the stringent emission regulations all over the world, the reduction of particulate emissions from diesel engines is of major interest. To enhance passive regeneration performance of catalyzed diesel particulate filter (CDPF), a NO2-assisted regeneration model is established in this work. In this article, optimal asymmetry ratio of diesel particulate filters was researched by comparing pressure drop under different operation conditions through the validated model and performances of passive regeneration of CDPF. Results show that deposition speed is equal to oxidation speed at the temperature of 330 degrees C, reaching balance state. With increasing of temperature, oxidation speed is improved greatly. With increasing of space velocity, oxidation rate decreases. And temperature has a more significant effect than space velocity. As NO2 concentration, O-2 concentration, and NO2/PM (particulate matter) ratio increase, oxidation rates are all improved, while importance of the influence on oxidation rate can be ordered that NO2/PM ratio NO2 O-2. Moreover, NO2/NOx ratio reaches its maximum value when inlet temperature is about 330 degrees C. NO2/NOx ratio decreases with increasing of space velocity. NO2/NOx ratio increases with increasing NO2, O-2 concentration, and NO2/PM ratio. The importance of the influence on NO2/NOx ratio can be ordered that O-2 NO2/PM ratio NO2. The results are valuable for performance enhancement of NO2-assisted regeneration and coupling different after-treatment systems.