System and method for reducing NOx emissions during transient conditions in a diesel fueled vehicle with EGR
USRE42609E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2009 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Sep 29, 2029 |
Classification
- Technology area (CPC —)General
Abstract
The present invention is a dual-stage fuel injection strategy for compression ignition engines in which 15-40% of the fuel is injected into the combustion chamber no later than about −20 to −30 CA ATDC and as early as IVC. The remaining fuel is then injected in one or more fuel pulses, none of which start before about −20 to −30 CA ATDC. The fuel injected early in the compression stroke forms a lean mixture that burns with low soot and low NOx emissions. The combustion of that fuel serves to increase in-cylinder temperature such that the ignition delay of subsequent fuel injection pulses is short. This mode is utilized when it is predicted that a NOx spike is imminent. Various other alternative methods for reducing NOx spikes are also disclosed such as specialized EGR systems that can provide EGR with low manifold vacuum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.