| abstract |
The present invention provides the deterioration of a kind of emission-control equipment to judge system, it is intended that have selective reduction type NO X In the deterioration judgement system of the emission-control equipment of catalyst, erroneous judgement during by judging deterioration suppresses, thus more improves the precision that deterioration judges.Using ammonia as the NO of reducing agent X The downstream part of catalyst possesses the catalyst with oxidability, at NO X The ammonia amount that catalyst is adsorbed, more than in the case of equilibrium adsorption capacity, has ammonia amount among the ammonia amount in the catalyst of oxidability, that flow out from the catalyst with oxidability or is converted into NO in the catalyst have oxidability inflow X Ammonia amount at least one party or aggregate values calculate, in the case of this value exceedes threshold value, deterioration judge in NO X The utilization of the detected value of sensor carries out limiting or forbid to deteriorate judgement itself. |