Exhaust aftertreatment system and doc NO2 generation on-board diagnostics method
US10494976B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2018 |
| Grant date | Dec 3, 2019 |
| Priority date | — |
| Expiry date | Mar 22, 2038 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for exhaust aftertreatment includes determining a diagnostic condition with respect to a threshold diagnostic condition, determining an SCR efficiency as a ratio of a readout of a first NOx sensor at a first NOx sensing position with respect to a readout of a second NOx sensor at a second NOx sensing position, the first NOx sensing position located about an engine out area within an exhaust stream before a DOC and the second NOx sensing position located about an output of an SCR device within the exhaust stream; and comparing the SCR efficiency to a threshold SCR efficiency range. If the SCR efficiency is less than the threshold SCR efficiency range, then trigger DOC failure for NO oxidation, and if the SCR efficiency is greater than or equal to the threshold SCR efficiency range, then DOC is determined to be operating within specifications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.