| 摘要 |
PROBLEM TO BE SOLVED: To effectively perform air system control during NOx purge or SOx purge without using a lambda value of exhaust gas.SOLUTION: An exhaust emission control system includes: a NOx reduction type catalyst 32 provided in an exhaust system of an internal combustion engine 10 to reduce and eliminate NOx in exhaust gas; and regeneration processing sections 60, 70 for lowering an excess air ratio of exhaust gas to a predetermined target excess air ratio to recover NOx elimination capacity of the NOx reduction type catalyst 32. The regeneration processing sections 60, 70 include: target setting sections 62, 72 for setting target suction air amount required for obtaining the target excess air ratio of the exhaust gas on the basis of the fuel injection amount of the internal combustion engine 10; and air system control sections 64, 74 for controlling at least one of the suction air amount and the exhaust gas recirculation amount in accordance with the target suction air amount input from the target setting sections 62, 72.SELECTED DRAWING: Figure 1 |
