Increasing exhaust temperature for aftertreatment operation
AssigneeCummins Inc.
InventorRoger D. England
Life of this patent
Estimating the term…
Abstract
One embodiment of the present invention includes an internal combustion engine system designed to increase exhaust temperature when operating with a low mechanical load—such as idle operation. This increased exhaust temperature is provided to operate aftertreatment equipment. Exhaust temperature is raised by operating a portion of the engine pistons in a brake mode to increase loading on a remainder of the pistons operating in a combustion mode to drive the engine. Fuel provided to pistons operating in the combustion mode is regulated to maintain speed of the engine within a desired idle speed range.
Claims20
A method, comprising:
- providing an internal combustion engine including a plurality of pistons each and aftertreatment equipment, the plurality of pistons corresponding to a plurality of respective cylinders and a plurality of respective exhaust valves, operation of the engine at idle including:
- powering the engine with a first number of the pistons operating in a combustion mode;
- by loading the engine with a second number of the pistons operating in a brake mode, increasing temperature of exhaust produced by the first number of pistons to heat the aftertreatment equipment to a desired operational level, wherein the brake mode includes pumping air in and out of the respective cylinders through the respective exhaust valves corresponding to the second number of pistons;
- and
- adjusting fueling provided to the first number of pistons operating in the combustion mode to maintain a desired idle speed of the engine as the temperature of the exhaust increases.
A method, comprising:
- regulating operation of an internal combustion engine system at idle, the system including an engine with a set of pistons and aftertreatment equipment to control emission from the engine, which includes:
- providing for operation of a first subset of the pistons in a combustion mode and a second subset of the pistons in a brake mode, the second subset of pistons each being disposed in a respective cylinder, wherein the brake mode includes pumping air in and out of the respective cylinder through at least one respective exhaust valve;
- increasing temperature of exhaust produced with the first subset of the pistons by operating the second subset of the pistons in the brake mode;
- as the temperature of the exhaust increases, adjusting fuel provided to the pistons in the first subset to maintain a desired idle speed of the engine;
- and
- changing quantity of the pistons in the first subset and the second subset to adjust the regulating of the engine system at idle.
An apparatus, comprising:
- an internal combustion engine system including an engine with a set of pistons and aftertreatment equipment, the set of pistons corresponding to a plurality of respective cylinders and a plurality of respective exhaust valves, the system including means for operating the engine at idle, the operating means including:
- means for driving the engine with a first subset of the pistons operating in a combustion mode;
- means for increasing temperature of exhaust produced by the first subset of pistons to heat the aftertreatment equipment to a desired operational level by loading the engine with a second subset of the pistons operating in a brake mode, wherein the brake mode includes means for pumping air in and out of the respective cylinders through the respective exhaust valves corresponding to the second subset of pistons;
- and
- means for adjusting fuel provided to the first subset of pistons operating in the combustion mode to maintain a desired idle speed of the engine as the temperature of the exhaust increases.
Dependencies are inferred from the claim text.