Method for managing temperatures in aftertreatment system
AssigneeDeere & Company
InventorsRichard E. Winsor, Jacob M. Rosswurm
Life of this patent
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Abstract
A method for managing temperatures in an aftertreatment system positioned downstream of an engine. The method includes (1) combusting a rich air/diesel mixture in a cylinder of the engine, and then (2) combusting a lean air/diesel mixture in the cylinder, in the next combustion event in the cylinder, after combusting the rich air/diesel mixture therein. The method further includes repeating steps (1) and (2) in the cylinder and basing a frequency thereof on a desired aftertreatment system temperature.
Claims12
A method for managing energy in an aftertreatment system positioned downstream of an engine, the aftertreatment system comprising a diesel oxidation catalyst, the method comprising:
- (a) combusting a lean air/diesel mixture in a cylinder of the engine;
- (b) determining whether an aftertreatment system temperature is above a threshold temperature;
- (c) combusting a rich air/diesel mixture in the cylinder following the determination that the aftertreatment system temperature is above the threshold temperature;
- (d) repeating transitions back-and-forth between (a) and (c) and basing a frequency of (c) on a cylinder temperature relative to a cylinder limit temperature;
- and
- (e) substantially always combusting an additional lean air/diesel mixture in the cylinder, in a next combustion event in the cylinder, after combusting the rich air/diesel mixture therein.
A method for managing energy in an aftertreatment system positioned downstream of an engine, the method comprising:
- (a) combusting a rich air/diesel mixture in a cylinder of the engine;
- (b) combusting a lean air/diesel mixture in the cylinder, in a next combustion event in the cylinder, after combusting the rich air/diesel mixture therein;
- (c) repeating transitions back-and-forth between (a) and (b) in the cylinder and basing a frequency of (a) on a desired aftertreatment system temperature rate increase;
- and
- (d) substantially always combusting a lean air/diesel mixture in a next cylinder immediately and sequentially after combusting the rich air/diesel mixture in the cylinder, the next cylinder being in a firing order that is immediately and sequentially after the cylinder.
A method for managing energy in an aftertreatment system positioned downstream of an engine, the aftertreatment system comprising a diesel oxidation catalyst, the method comprising:
- (a) combusting a lean air/diesel mixture in a cylinder of the engine;
- (b) combusting a rich air/diesel mixture in the cylinder;
- and
- (c) repeating transitions back-and-forth between (a) and (b), and when an aftertreatment system temperature is above a threshold aftertreatment temperature but below a desired aftertreatment temperature, (a) occurs in between 2% and 45% of the combustion events in the cylinder.
Dependencies are inferred from the claim text.