An internal combustion engine for a motor vehicle is disclosed. The engine has at least two combustion chambers and an exhaust gas tract with at least one exhaust gas duct associated with the combustion chambers and through which exhaust gas from the combustion chambers can flow to guide the exhaust gas to a turbine of an exhaust gas turbocharger. An exhaust gas return line branches off the exhaust gas duct and has an adjustable shut-off element, by which a respective cross section, through which exhaust gas can flow, of the exhaust gas recirculation line and the exhaust gas duct can be adjusted. The internal combustion engine can be operated in a cylinder shut-down mode, in which introduction of fuel into a first of the combustion chambers is prevented and introduction of fuel into the second combustion chamber takes place. A method for operating the internal combustion engine is also disclosed.

An internal combustion engine for a motor vehicle is disclosed. The engine has at least two combustion chambers and an exhaust gas tract with at least one exhaust gas duct associated with the combustion chambers and through which exhaust gas from the combustion chambers can flow to guide the exhaust gas to a turbine of an exhaust gas turbocharger. An exhaust gas return line branches off the exhaust gas duct and has an adjustable shut-off element, by which a respective cross section, through which exhaust gas can flow, of the exhaust gas recirculation line and the exhaust gas duct can be adjusted. The internal combustion engine can be operated in a cylinder shut-down mode, in which introduction of fuel into a first of the combustion chambers is prevented and introduction of fuel into the second combustion chamber takes place. A method for operating the internal combustion engine is also disclosed.

A system and method of integrating an engine having dynamic skip fire control with an exhaust gas recirculation system in a turbocharged internal combustion engine is described. An engine control system determines an appropriate firing pattern based at least in part on a desired exhaust gas recirculation flow rate. Signals from sensors in the intake manifold and exhaust system may also be used as part of a feedback loop to determine a desired exhaust gas recirculation flow rate.

A method of controlling fuel injection to the cylinders of an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder, with the other cylinders being main cylinders. The D-EGR cylinder is run at a richer equivalence ratio than the main cylinders, with the goal of providing increased H2 and CO in the recirculated exhaust. The rich limit of the D-EGR cylinder is maximized by dividing the fuel injection into multiple fuel injection events, with each fuel injection event occurring during the intake valve lift period of the engine cycle.

A method of controlling fuel injection to the cylinders of an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder, with the other cylinders being main cylinders. The D-EGR cylinder is run at a richer equivalence ratio than the main cylinders, with the goal of providing increased H2 and CO in the recirculated exhaust. The rich limit of the D-EGR cylinder is maximized by dividing the fuel injection into multiple fuel injection events, with each fuel injection event occurring during the intake valve lift period of the engine cycle.

Systems are provided for detecting a change in performance of an engine component. In one example, a system includes a first pressure sensor of a first exhaust manifold coupled to a first subset of cylinders of an engine, a second pressure sensor of a second exhaust manifold coupled to a second subset of cylinders of the engine, a passage coupling the first exhaust manifold to an intake manifold, and a controller configured to detect a change in performance of any cylinder of the engine based on frequency content from the first pressure sensor and from the second pressure sensor during both a first mode where no exhaust gas from the first exhaust manifold is provided to the intake manifold, and during a second mode where all exhaust gas from the first exhaust manifold is provided to the intake manifold, and adjust an operating parameter responsive to the change in performance.

Methods and systems are provided for controlling engine operation in a hybrid vehicle, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to the intake manifold. In one example, if an engine load decreases below a level where dedicated exhaust gas recirculation may lead to combustion stability issues, engine load may be increased above the demanded load and the excess power used to charge a system battery, or if the battery state of charge is above a threshold, the engine may be shut down and the vehicle propelled via battery power. In this way, fuel economy and combustion stability issues may be improved, NOx emissions reduced, and costs for implementation of dedicated exhaust gas recirculation decreased.

Methods and systems are provided for controlling hybrid vehicle engine operation, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to an intake manifold. In one example, during an engine cold-start event or other event where temperature of one or more exhaust catalysts are below a temperature needed for catalytic activity, fuel injection to the dedicated exhaust gas recirculation cylinder(s) is maintained shut off, while its intake and exhaust valves are maintained activated, thus enabling the dedicated exhaust gas recirculation cylinder(s) to route air to the intake manifold of the engine, resulting in exhaust gas lean of stoichiometry that may serve to heat the catalyst. In this way, during cold start events and other events where temperature of one or more exhaust catalysts are below a temperature for catalytic activity, combustion stability issues may be avoided, and exhaust catalyst(s) rapidly heated, thereby reducing undesired tailpipe emissions.

An engine system includes an intake passage, a non-deactivation exhaust passage, a second exhaust manifold, a first turbocharger including a first turbine rotated by exhaust gas flowing via the first exhaust manifold, a second turbocharger including a second turbine rotated by exhaust gas flowing via the second exhaust manifold, an exhaust outlet, a main intake circulation passage in communication with the intake passage via a compressor of the first turbocharger such that supercharging air is supplied to the intake passage, a sub intake circulation passage in communication with the main intake circulation passage via a compressor of the second turbocharger such that supercharging air is supplied to the main intake circulation passage, and a deactivation valve disposed on the sub intake circulation passage between the compressor of the second turbocharger and the main intake circulation passage so as to selectively open/close the sub intake circulation passage.

The present disclosure relates to an apparatus and method for increasing the level of hydrogen produced in an exhaust gas recirculation pathway within an internal combustion engine. A hydrocarbon water gas shift reformer is positioned in series with a water gas shift reformer within the exhaust gas recirculation pathway to improve the yield of hydrogen and to improve the relative efficiency of both catalytic procedures.