Abnormality detection apparatus for exhaust gas purification apparatus and abnormality detection method for exhaust gas purification apparatus
US8844268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2009 |
| Grant date | Sep 30, 2014 |
| Priority date | — |
| Expiry date | Aug 27, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
It is determined quickly whether there is a shortage in reducing agent supplied to an NOx selective reduction catalyst. After it is determined that a quantity of reducing agent equal to or larger than a predetermined quantity is absorbed in the NOx selective reduction catalyst on the assumption that there is no abnormality in reducing agent supply unit, the supply of a quantity of reducing agent needed to reduce a quantity of NOx flowing into the NOx selective reduction catalyst is started. A determination of an abnormality in the reducing agent supply unit is made based on the NOx removal rate after the lapse of a predetermined period of time since the start of the supply of reducing agent. The NOx removal rate becomes lower when there is an abnormality in the reducing agent supply unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.