Exhaust gas purification system for internal combustion engine
US8336296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 2008 |
| Grant date | Dec 25, 2012 |
| Priority date | — |
| Expiry date | Jan 7, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An object of the present invention is to provide a technology that enables reduction of NOx stored in an NOx catalyst with improved efficiency in an exhaust gas purification system for an internal combustion engine. According to the present invention, when NOx stored in the NOx catalyst is to be reduced, if the temperature of the NOx catalyst is lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased only by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine, and if the temperature of the NOx catalyst is not lower than the specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased either only by adding reducing agent through reducing agent addition means, or by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine and adding reducing agent through the reducing agent addition means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.