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US 11,047,322 B2Granted
Split exhaust engine with idle check valve
AssigneeFord Global Technologies, LLC
InventorsJoseph Ulrey, John Erik Mikael Hellstrom, Daniel Madison, Christopher John Piper, Andres Ceballos
Life of this patent
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Abstract
Methods and systems are provided for reducing exhaust residuals during light load conditions in a split exhaust engine via a check valve. In one example, a scavenge exhaust manifold may be maintained above a threshold pressure by introducing fresh air into the scavenge manifold during a valve overlap period, the scavenge manifold coupled to a cylinder of an engine and coupled to an intake passage of the engine.
Claims11
A method, comprising:
- maintaining a scavenge exhaust manifold above a threshold pressure by introducing fresh air into the scavenge exhaust manifold during a valve overlap period, the scavenge exhaust manifold coupled to a cylinder of an engine and coupled to an intake passage of the engine,
- wherein maintaining the scavenge exhaust manifold above the threshold pressure by introducing the fresh air into the scavenge exhaust manifold during the valve overlap period comprises admitting the fresh air into the scavenge exhaust manifold during the valve overlap period via a check valve positioned in a conduit, the conduit fluidly coupled to the scavenge exhaust manifold at a first end and fluidly coupled to the intake passage at a second end, and the conduit fluidly coupled to the intake passage at a location of the intake passage that is upstream of an intake throttle, and
- further comprising, during low engine load conditions, retarding exhaust valve closing timing for both a blowdown exhaust valve coupling the cylinder to a turbine and a scavenge exhaust valve.
A method, comprising:
- during low engine load conditions, retarding exhaust valve closing timing for both a blowdown exhaust valve coupling a cylinder of an engine to a turbine and a scavenge exhaust valve coupling the cylinder to an intake passage of the engine via a scavenge manifold;
- and
- reducing exhaust residuals in the cylinder by admitting intake air into the scavenge manifold during a valve overlap period,
- wherein admitting the intake air into the scavenge manifold comprises admitting the intake air to the scavenge manifold via a check valve positioned between the scavenge manifold and the intake passage upstream of a compressor.
1 more element
A method, comprising:
- during low engine load conditions, retarding exhaust valve closing timing for both a blowdown exhaust valve coupling a cylinder of an engine to a turbine and a scavenge exhaust valve coupling the cylinder to an intake of the engine via a scavenge manifold;
- reducing exhaust residuals in the cylinder by admitting intake air into the scavenge manifold during a valve overlap period;
- and
- during the low engine load conditions, closing a scavenge wastegate coupling the scavenge manifold to an exhaust of the engine downstream of the turbine and closing a turbine wastegate coupled across the turbine.
1 more element
Dependencies are inferred from the claim text.