| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect a deterioration of an oxidation catalyst from a heating value in the oxidation catalyst even when an error is caused in the added amount of fuel to exhaust gas, and even when the properties of added fuel are changed. <P>SOLUTION: A reference oxidation catalyst is provided separately from an oxidation catalyst (DOC) that is an object of deterioration detection. In deterioration detection, fuel-added exhaust gas is caused to flow into the reference oxidation catalyst (S102), and a reference heating value in the reference oxidation catalyst at that time is calculated (S112). Next, fuel-added exhaust gas is caused to flow into the oxidation catalyst that is the object of deterioration detection (S113), and the heating value amount in the oxidation catalyst at that time is calculated (S119). Whether the heating value in the oxidation catalyst is reduced is determined based on the ratio of the heating value to the reference heating value (S120), and when the heating value in the oxidation catalyst is reduced, deterioration of the oxidation catalyst is determined (S121). <P>COPYRIGHT: (C)2013,JPO&INPIT |
