ABNORMALITY DETERMINATION SYSTEM OF EXHAUST EMISSION CONTROLLER

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission controller configured to contain a NOx catalyst that is a selective reduction NOx catalyst and capable of appropriately determining abnormality relating to supply of a reducer for NOx purification.SOLUTION: An abnormality determination system of an exhaust emission controller comprises: a catalyst portion including an upstream catalyst region and a downstream catalyst region formed to contain a selective reduction NOx catalyst; a reducer supply portion; and an abnormality determination unit determining abnormality relating to the reducer supply portion. Furthermore, the catalyst portion is configured such that, if the reducer supply portion is in a normal state, an adsorption quantity of ammonia adsorbed in the upstream catalyst region belongs to a first range and that an adsorption quantity of ammonia adsorbed in the downstream catalyst region belongs to a second range that is a smaller quantity range and that does not overlap the first region. The abnormality determination unit determines that the reducer supply portion is in an abnormal state if a NOx purification rate in the downstream catalyst region is lower than a predetermined purification rate set related to a lower limit value of the second range.