The application of thermal, catalytic and non-thermal plasma oxidation processes to enhance NO-NO\(_2\)oxidation in the engine exhaust and improve DPF regeneration at lower temperatures

[摘要] Diesel Particulate Filter (DPF) is believed to be one of the most effective methods and provides an efficient system that traps more than 90% of PM. However, the soot accumulated within the filter requires a regeneration process to recover its performance. Thus, the high oxidation ability of NO-NO\(_2\) increases the interest of applying it in the low temperature regeneration process. The intention of this thesis is to investigate several possibilities of on-board NO-NO\(_2\) oxidation methods for increasing the NO\(_2\)/NO\(_X\) ratio in the exhaust gas. These possible oxidation routes incorporate the in-cylinder to the exhaust gas treatment processes. A wide range of operated temperatures are managed by the application of the non-thermal plasma oxidation (NTP) for low temperatures, catalytic oxidation for moderated temperatures and thermal oxidation for high temperatures studied. The in-cylinder NO oxidation was significantly improved by adding H\(_2\) or the reformed EGR (REGR) to the combustion. The remaining H\(_2\) after the combustion also contributes to the downstream HC-SCR which in turn promotes the NO oxidation. The thermal and NTP methods in the exhaust treatment cannot adequately achieve a satisfactory NO oxidation result under a single occupied condition. The propane (C\(_3\)H\(_8\)) addition may potentially create useful radicals (HO\(_2\), RO\(_2\)) within the system and convert a large portion of NO into NO\(_2\).

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Mechanical Engineering

[关键词] T Technology;TJ Mechanical engineering and machinery