Catalytic converter degradation determining system
US7409821B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 2005 |
| Grant date | Aug 12, 2008 |
| Priority date | — |
| Expiry date | Nov 29, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A catalytic converter degradation determining system is configured to accurately determine if a NOx trapping catalytic converter is degraded. The system is configured to detect or estimate the temperature of a NOx trapping catalytic converter and sets a pre-degradation adsorption efficiency and a post-degradation adsorption efficiency based on the catalytic converter temperature. The system then multiplies the adsorption efficiencies by an exhaust gas NOx quantity to calculate trapped NOx rates. The individual trapping NOx rates are summed over a prescribed amount of time to estimate the pre-degradation and post-degradation NOx trapping amounts. After the prescribed amount of time elapses, the system compares the pre-degradation NOx trapping amount to the post-degradation NOx trapping amount and determines if the difference between the two is smaller than a prescribed value. If the difference is smaller than the prescribed value, then the system determines that the catalytic converter is degraded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.