Method to improve blowthrough and egr via split exhaust
AssigneeFord Global Technologies, LLC
InventorsDaniel Paul Madison, Joseph Norman Ulrey, Brad Alan Boyer
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for a boosted engine having a split exhaust system. In one example, a method comprises directing exhaust from a first cylinder group to one or more of a pre-compressor location, a post-compressor location, and an exhaust turbine, and directing exhaust from a second cylinder group to one or more of the pre-compressor location, and the exhaust turbine. Engine efficiency and knock control may be enhanced by directing exhaust gases to different locations based on engine operating conditions.
Claims20
A method for an engine, comprising:
- directing exhaust from a first cylinder group to one or more of a pre-compressor location, a post-compressor location, and an exhaust turbine;
- and
- directing exhaust from a second cylinder group to one or more of the pre-compressor location, and the exhaust turbine.
A method for an engine, comprising:
- during a first condition, recirculating a combination of residual exhaust gases and blowthrough air from a plurality of cylinders of the engine to upstream of a compressor in a first engine cycle;
- and
- during a second condition, recirculating all exhaust from only a subset of the plurality of cylinders to downstream of the compressor and delivering exhaust gases from remaining cylinders to an exhaust turbine in a second engine cycle.
A system, comprising:
- an engine having an intake manifold and an exhaust manifold, the exhaust manifold fluidically coupled to an emissions control device;
- an intake throttle positioned in an intake passage coupled upstream of the intake manifold;
- a turbocharger including an intake compressor driven by an exhaust turbine;
- a plurality of cylinders each including a first exhaust valve, a second exhaust valve, and a third exhaust valve;
- a first exhaust passage fluidically coupling the first exhaust valve directly to only a turbine of the turbocharger;
- a second exhaust passage fluidically coupling the second exhaust valve directly to only an emissions control device;
- a third passage fluidically coupling the third exhaust valve directly to only an inlet of the intake compressor;
- a fourth passage fluidically coupling the third exhaust valve directly to the intake passage, downstream of the intake compressor, downstream of the intake throttle, and upstream of the intake manifold;
- a first exhaust recirculation valve positioned within the third passage;
- a second exhaust recirculation valve positioned within the fourth passage;
- and
- a cam profile switching system coupled to each of the first exhaust valve, the second exhaust valve, and the third exhaust valve of each of the plurality of cylinders.
Dependencies are inferred from the claim text.