Computational Investigation Of Continuously Regeneration Characteristics In Diesel Particulate Filter

Diesel Particulate Filter?DPF? has been a research hotpot as it is one of the most effective way to eliminate diesel particulate matter. There are many ways in DPF regeneration. Continuous regeneration has less energy consumption and a wide regeneration temperature window, which make it get a lot of attention. A numerical model of Catalyzed Continuously Regenerating Technology?CCRT? was established in this paper, and the influence of different factors on regeneration performance of CCRT was studied.The regeneration performance of CCRT, CSF and CRT was compared. It can be seen that compared with CSF and CRT, CCRT has a better regeneration performance as it has a lower regeneration balance point, a slower low temperature filtration rate and a faster high temperature regeneration rate.The influence of ash mass and distributions on CCRT regeneration performance was studied. It indicates that: when there is more ash in DPF channels, the overall pressure drop, maximum regeneration temperature and regeneration balance point will go higher; when there is particulate exists in CSF, a higher overall pressure drop and a higher maximum regeneration temperature will be seen in the condition of a smaller ash distribution factor; the minimum overall pressure drop will be achieved when the ash is all on the channel surface and the highest point of ash layer occurs at the end of channel; the maximum regeneration temperature always occurs at the end of effective filtration length; the maximum regeneration temperature will be higher and more closer to the channel inlet when there is more ash and a smaller ash distribution factor.The effect of NO₂ and O₂ concentration, different CPSI?Cells Per Square Inch?, volume ratio of DOC/CSF and channel structure on CCRT regeneration were also investigated. The results show that: a higher NO₂ and O₂ concentration will lead to a faster regeneration rate, which makes the regeneration balance point lower; the channel wall thickness will be smaller when CPSI goes bigger, and the overall pressure drop becomes smaller at the same time; when selecting DOC to match with CSF, the DOC that has the same sectional area with CSF and 1.5 times volume of CSF is proper, and the conversions of CO,HC and NO reach nearly 100% at this time; the hexagonal channel structure has the lower overall pressure drop compared with square and octagonal channel structure in the condition of same CPSI, because it has the biggest inlet/outlet channel interface area.Depending on the conclusions above, a structure optimization scheme was put forward at last.