Development of DPF System for Commercial Vehicle - Basic Characteristic and Active Regenerating Performance -

摘要: Diesel Particulate Filters (DPFs) having an effectiveness of around 90% reduction particulate matter (PM) are essential after-treatment technique in order to meet upcoming PM regulations (Japan2005, Euro4, US07), which all increasingly stringent. The continuous-regenerating DPF system [1] has been drawing particular attention, because it is possible significantly simplify the and reduce costs. study presented herein investigated application a commercial vehicles. Since exhaust temperatures that encountered during significant portion engine operation too low initiate oxidation PM, continuously regenerating must employ catalyst. However, when basic characteristics were investigated, adequate rate was not obtained city mode operation, temperature notably low. Consequently, continuous regeneration did occur, necessary utilize active [2] forcibly oxidize remove PM. Moreover, high-load operating conditions, more accumulated on filter, rapid inside filter generated extremely high temperature, resulting breakage. Recently combustion phenomena under going be analyzed by using visual method [3]. In this work, robust SiC [4][5] used withstand prevent black smoke leakage. Next, carried out driving investigated. method, fuel injection process modified such additional late into cylinder (post-injection) took place. This supplied unburned pre-catalyst, combusted heat oxidation. Therefore, first achieving controlled catalyst heat-up, brought pre-catalyst up activation (1st stage), followed heat-up post-injection (2nd became sufficiently so oxidized then regenerated actively. A feedback devised control process, suppress abnormal regeneration, obtain acceptable efficiency. With control, initiated vehicle very stable, good efficiency obtained. Based above results, suggested for vehicles frequently operated mode, high-reliability, devised. For practical use future, there still tasks solved, example, how ash build-up filter. offers reduced impact environment would hopefully realized soon.