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US 9,038,580 B2Granted
Method and system for engine dilution control
AssigneeFord Global Technologies, LLC
InventorsGopichandra Surnilla, Thomas G. Leone, Brad Alan VanDerWege, Christopher House, Michael Howard Shelby
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Abstract
Methods and systems are provided for enabling engine dilution control. One or more engine diluents are combined to provide a desired engine dilution, the various diluents selected based on their respective combustion stability limits. A ratio of the various diluents used is further adjusted based on engine operating limitations.
Claims19
A method of operating an engine, comprising:
- providing a desired engine dilution by combining a plurality of engine diluents, the diluents and their ratio selected based on respective combustion stability limits, the providing including increasing a first amount of a first diluent while decreasing a second amount of a second diluent, the first and the second amounts based on a determination of knock.
A method of operating an engine, comprising:
- recirculating a first amount of exhaust gas from an engine exhaust to an engine intake to provide at least some of a desired engine dilution until a first combustion stability limit of the exhaust gas recirculation is reached;
- and
- after reaching the first combustion stability limit, injecting a second amount of engine diluent to provide a remainder of the desired engine dilution, the second amount based on a combustion stability limit of the first amount of exhaust gas, the first and second amounts adjusted to provide the desired engine dilution, the second amount of exhaust gas engine diluent decreased as the first amount of recirculated exhaust gas is increased.
An engine system, comprising:
- an engine including an intake and an exhaust;
- an injector configured to direct inject a fluid into an engine cylinder;
- an EGR passage for recirculating an amount of exhaust gas from the engine exhaust to the engine intake;
- a controller with computer readable instructions for:
- in response to a likelihood of knock,
- recirculating a first amount of exhaust gas via the EGR passage until a first combustion stability limit of the EGR is reached;
- and
- after the first combustion stability is reached, direct injecting a second amount of water into the engine cylinder until a second combustion stability limit of the direct injection is reached, wherein the first and second amounts are based on the likelihood of knock and each of the first and second combustion stability limits, the second amount of water decreased as the first amount of exhaust gas recirculation is increased to provide a desired engine dilution.
5 more elements
Dependencies are inferred from the claim text.