EXHAUST EMISSION CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To effectively prevent a rapid rise of an engine temperature during regeneration processing of a catalyst.SOLUTION: An exhaust emission control system includes: a NOx reduction type catalyst 32 arranged in an exhaust passage 13 of an internal combustion engine 10 to reduce NOx in exhaust gas for purification; a regeneration control section 60 for executing regeneration processing for recovering NOx elimination capacity of the NOx reduction type catalyst 32 by making exhaust gas rich; an engine speed sensor 41 for acquiring speed of the internal combustion engine; and a regeneration prohibition section 70 for prohibiting the regeneration processing executed by the regeneration control section 60 when the speed acquired by the engine speed sensor 41 becomes higher than a predetermined upper limit speed threshold value.SELECTED DRAWING: Figure 1