Full course evolution characteristics of DPF active regeneration under different inlet HC concentrations

Abstract

Due to their high thermal efficiency, good reliability and durability, low fuel consumption, and low carbon dioxide emission, diesel engines are widely used in both stationary and mobile applications. However, the inherent combustion mode of diesel engines results in high particulate matter (PM) emissions. In order to meet the increasingly stringent PM emission standard, the diesel particulate filter (DPF) has become a necessary configuration to remove PM for diesel engines. Increasing damage of fuel consumption with DPF soot loading leads to the requirement of regeneration process. DPF active regeneration is a process from hydrocarbon (HC) oxidation in diesel oxidation catalyst (DOC) to deposited particle oxidation in DPF, involving the whole aftertreatment system. First, previous studies mainly focused on single converter, and have rarely explored the regeneration process considering the whole aftertreatment system. Second, few studies have conducted in-depth introductions to the microscopic oxidation characteristics of deposited particles during regeneration. Third, the high temperature resulted from the active regeneration has an important impact on the performance of selective catalytic reduction (SCR), which may be a problem to be considered in the next emission regulations, but few studies have reported this aspect. This study focuses on full course evolution process under DPF active regeneration considering the whole aftertreatment system. Taking the HC concentration as the research variables, the HC slip phenomenon, the microscopic oxidation characteristics of deposited particles, the temperature field characteristics, and the influence of active regeneration on SCR performance are systematically investigated. This study can provide valuable guidance for further understanding of DPF active regeneration characteristics, regeneration control strategy formulation and DPF durability improvement.