DPF Passive Regeneration Approach for CEV/TREM-V Off-Highway Applications

With introduction of Diesel Particulate Filter to achieve CEV/TREM V Emission Limits for off-highway segment, requirement of DPF regeneration at defined intervals depending on time of operation and soot loading of DPF. This can be achieved by two methods. First is the frequent regeneration or active regeneration, wherein fuel is injected before DOC (Diesel Oxidation Catalyst) at specific temperature to burn the soot in the DPF. The second method is the continuous or passive regeneration, where soot is burnt based on NO2. DPF frequent regeneration (Active Regeneration) requires soot load estimation in DPF over entire engine operation range as well as vehicle operation in different climatic conditions. Frequent regeneration leads to oil dilution and penalty in the fuel consumption. More frequent regeneration promotes the chemical aging of DOC , leading to the poor performance of DOC which results in deteriorated performance of SCR(Selective Catalytic Reduction) situated at downstream of DPF. In addition to Passive Regeneration Approach, modelled air path is used as complexity of using Mass Flow Sensors lies with robust calibration of air system model considering different vehicle variants/change in layout in real world & owing to dust contamination in Off-Road Vehicles. To avoid the shortcomings of the frequent regeneration in off-road application, the DPF regeneration was achieved by passive regeneration approach. In this paper, the passive regeneration will be discussed in detail for CEV/TREM V Legislation. Key Word: CEV / TREM V, Passive Regeneration, DPF regeneration, Off Road application, Fuel Consumption, Air Path Model , DOC Catalyst Aging.