| 摘要 |
<p>PURPOSE:To hold high NOx cleaning rate while suppressing deterioration of specific fuel consumption to the lowest. CONSTITUTION:In an exhaust passage 13 of a diesel engine 11, the first NOx reduction catalyst 14 for using carbon as a reducing agent, HC addition means 15 for adding HC in exhaust gas, the second NOx reduction catalyst 16 using HC as a reducing agent are arranged in series. An exhaust bypass passage 17 for bypassing the first NOx reduction catalyst 14 is arranged parallel to the first NOx reducing catalyst 14, and switch valves 18, 20 for selecting a flowing passage between the exhaust bypass passage 17 and the first NOx reducing catalyst 14 and a controller 21 for controlling the switch valves 18, 20 are provided.</p> |
