Various methods and systems are provided for using only hydrogen as fuel in a duel fuel engine. In one example, a method may include direct injecting only hydrogen as fuel to one or more engine cylinders and compression igniting the injected hydrogen.

Embodiments for inducing swirl upstream of a compressor are provided. In one example, a method includes during a first condition, flowing exhaust gas from downstream of a turbine to upstream of a compressor via a tangential flow duct of an exhaust gas recirculation (EGR) injector circumferentially surrounding an intake passage upstream of the compressor, and during a second condition, flowing exhaust gas from downstream of the turbine to upstream of the compressor via a radial flow duct of the EGR injector.

Methods and systems are provided for controlling the temperature and ratio of gases within a gas mixing tank reservoir and selectively charging/discharging gases from the reservoir to one or both of an intake system or an exhaust system. In one example, a method (or system) may include storing exhaust gas and/or compressed intake air into a gas mixing reservoir, and increasing or decreasing flow of coolant to the reservoir based on engine operating conditions. The stored gases may be discharged to an intake system and/or an exhaust system based on requests from a controller, and coolant flow to the reservoir may be adjusted based on the composition of the gases stored within the reservoir.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

An exhaust gas recirculation system for an engine includes a conduit, and a mixer. The conduit is configured to direct to direct exhaust gas away from an exhaust manifold. The mixer is configured to direct exhaust gas from the conduit, into an engine air intake system. The mixer is arranged with an exhaust gas mixing volute chamber having a plurality of mixing vanes configured to direct the exhaust gas into a central intake airflow upstream of an intake manifold.

A control device estimates a leakage gas amount with respect to gas that leaks to an upstream side from a downstream side of a fresh air introduction valve when the fresh air introduction valve is closed. If the leakage gas amount is equal to or greater than a predetermined value when there is a request to open the fresh air introduction valve, a target opening degree of the fresh air introduction valve is determined based on the engine speed and intake pressure, and also a correction opening degree with respect to the target opening degree is calculated based on the leakage gas amount. The fresh air introduction valve is opened to an opening degree greater than the target opening degree by an amount corresponding to the correction opening degree, to thereby cause leakage gas that is accumulated in a fresh air introduction passage to flow into an intake passage together with a required amount of fresh air.

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.

An internal combustion engine system including an internal combustion engine and an exhaust gas recirculation circuit connecting an exhaust manifold of the engine to an intake manifold of the engine, the circuit including at least one reed valve, an EGR valve, that is arranged downstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold to the intake manifold and an EGR line connecting the reed valve to the EGR valve. The system further includes a bypass line for gas, connecting the EGR line to an exhaust line of the engine and controller for controlling the flow of gas discharged through the bypass line.

A method of operating exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an system controller; providing an EGR control unit linked to the EGR pump assembly; sending a speed command from the system controller to the EGR control unit; determining if a motor temperature and module temperature is within a predetermined target; outputting a desired speed signal; determining if a motor speed is within a predetermined target; determining if a motor voltage is within a predetermined target; and outputting a current to the electric motor controlling the speed of the electric motor and regulating an EGR mass flow rate.

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.