| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine in which a NOx reduction catalyst can be activated effectively in the early stage after the start of operation. <P>SOLUTION: In case of cold machine state, operation of an EGR system 40, for example, is stopped (S1) by cold machine time operation control performed by an ECU 50. In S2, it is detected whether or not the internal combustion engine is in cold machine state, and if YES, then the control proceeds to S3 by judging that the cold machine state is continuing and if NO, then the control proceeds to S5 by judging that it is shifted to warmed up state. In S5, addition of urea water to exhaust gas is started by stopping or limiting the operation of a burner 10 and normal operation of the EGR system 40 is permitted. In S3, the burner 10 is operated in order to activate an urea SCR catalyst 5 in the early stage. In S4, it is judged whether or not the outlet temperature of the urea SCR catalyst 5 has reached an activation judgement temperature or more, and if YES, then the control proceeds to step S5. If NO, then the control returns back to S3 and the operation of the burner 10 is continued until the outlet temperature of the urea SCR catalyst 5 reaches the activation judgment temperature or more. <P>COPYRIGHT: (C)2009,JPO&INPIT |
