Abstract:
Various systems and method for controlling exhaust gas recirculation (EGR) in an internal combustion engine are provided. In one embodiment, a method includes injecting fuel to a subset of cylinders that includes less than all cylinders of a first cylinder group to obtain a target EGR rate. The first cylinder group provides exhaust gas through an exhaust gas recirculation (EGR) passage structure fluidly coupled between the first cylinder group and an intake passage structure. The method further includes injecting fuel to at least one cylinder of a second cylinder group. The second cylinder group provides substantially no exhaust gas through the EGR passage structure.
Abstract:
Various methods for controlling EGR rate are disclosed. In one embodiment, a method comprises routing at least a portion of exhaust from a first exhaust manifold to an intake manifold, and not to atmosphere, the first exhaust manifold exclusively coupled to a first cylinder group. The method further includes routing exhaust from at least one additional exhaust manifold coupled to a corresponding at least one additional cylinder group to atmosphere, and during a first engine operating condition where an engine fuel demand is below a threshold demand, not injecting fuel to each of a subset of cylinders in the first cylinder group while injecting fuel to a subset of all cylinders coupled to the at least one additional exhaust manifold, where a number of cylinders of the subset of cylinders in the first cylinder group decreases in response to an increase in a target EGR rate.
Abstract:
Various methods and systems are provided for adjusting a flow of exhaust gas in an exhaust gas recirculation system. In one embodiment, a method for an engine comprises controlling a flow of exhaust gas through an exhaust gas recirculation system of an engine system based on a choke level of a turbocharger. For example, the flow of exhaust gas in the exhaust gas recirculation system may be reduced to within a threshold of a choke level of the turbocharger, in response to an ambient condition.
Abstract:
Various methods and systems are provided for estimating a wall temperature in a heat exchanger and reducing the risk of boiling on a coolant side of the heat exchanger. In one embodiment, a method for an engine comprises estimating a wall temperature at a location in a heat exchanger and adjusting an engine operating parameter of an engine coupled to the heat exchanger based on the wall temperature.
Abstract:
Various methods and systems are provided for determining a surge level of a compressor. In one embodiment, a method for an engine comprises updating a stored estimate of a surge level of a compressor responsive to detection of a surge event.
Abstract:
Various methods and systems are provided for adjusting a flow of exhaust gas in an exhaust gas recirculation system. In one embodiment, a method for an engine comprises controlling a flow of exhaust gas through an exhaust gas recirculation system of an engine system based on a choke level of a turbocharger. For example, the flow of exhaust gas in the exhaust gas recirculation system may be reduced to within a threshold of a choke level of the turbocharger, in response to an ambient condition.