The NO ₂ Emission Characteristics of Catalyzed Diesel Particulate Filter Regeneration

A simulation model of catalyzed diesel particulate filter (CDPF) is established based on the CFD software FIRE and has been validated through a series of experimental comparison. This model simulates the CDPF continuous regeneration process, and the factors that influence the exhaust NO₂ concentration from CDPF including oxygen concentration, exhaust temperature, space velocity, proportion of NO₂/NO_X and soot mass fraction are studied. The results show that the higher oxygen concentration causes an increase in NO₂/NO_X. The NO₂/NO_X is significantly increased when the exhaust temperature is about 350 °C based on the simulation conditions when the inlet oxygen concentration is at 5.79% and the space velocity is 7s⁻¹. The space velocity in a certain degree leads to higher NO₂/NO_X. For the soot mass, there is no significant influence of increasing proportion of the NO₂/NO_X.