Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include accelerating an electric supercharger to choke the flow of air to the engine in the event of turbocharger overboost.

Various methods and systems are provided for controlling air flow in a two-stage turbocharger. In one example, an engine method comprises adjusting one or more exhaust gas recirculation valves to maintain a first turbocharger within a first air flow range, and adjusting a turbocharger bypass valve to maintain a second turbocharger within a second air flow range.

The present disclosure provides a device for variably controlling a flow rate of intake air of a turbocharger compressor including a housing, a compressor wheel, a sliding insert disposed in a straight tube in the housing coaxially with the straight tube, wherein the sliding insert variably adjusts an intake air recirculation passageway while moving closer to or farther from the straight tube in an axial direction, and a drive unit which provides power for moving the sliding insert, such that efficiency of the compressor may be improved because a flow rate of intake air is increased as the intake air is recirculated, and performance of an engine may be improved by improving performance of a turbocharger because an air amount required for the engine may be controlled by means of a variable slit structure.

The present disclosure provides a boosting control method of an engine for cylinder de-activation (CDA). The method includes: a CDA operable area confirming step of determining, by a controller based on a driving state of the engine, whether the CDA is in an operable area after the engine starts; an actual boosting deriving step of deriving a total target boosting from the controller and calculating the desired actual boosting; a supercharger operable area confirming step of determining, by the controller, whether the supercharger is in the operable area; a supercharger target rotation speed deriving step of deriving, by the controller, a target rotation speed of the supercharger; and a supercharger passage opening step of closing a bypass valve to open a supercharger passage.

Methods and systems are provided for controlling canister purge flow in a boosted engine. An example method for the boosted engine comprises, during boosted conditions, flowing stored fuel vapors from a canister into an ejector coupled in a compressor bypass passage, the flowing bypassing a canister purge valve. The method further comprises, responsive to a canister load higher than a threshold load, closing a canister vent valve coupled to the canister, and discontinuing flowing stored fuel vapors from the canister into the ejector.

A control device for an engine, the engine includes an exhaust gas control apparatus that is configured to store NOx and react NOx with a reduction agent. The control device includes an electronic control unit. The electronic control unit is configured to: (i) execute a rich spike control, the rich spike control is a control executed to temporarily change an in-cylinder air-fuel ratio from a leaner air-fuel ratio than the stoichiometric air-fuel ratio to the stoichiometric air-fuel ratio or a richer air-fuel ratio than the stoichiometric air-fuel ratio, and (ii) vary an overlap amount of an intake valve and an exhaust valve such that the overlap amount is less during non-execution of the rich spike control than during execution of the rich spike control, in an operation range where a pressure of the intake port becomes higher than a pressure of the exhaust port.

Embodiments for controlling exhaust gas turbines are provided. In one embodiment, a method for controlling a turbocharger arrangement of an internal combustion engine, the turbocharger arrangement having at least a first exhaust-gas turbine and a second exhaust-gas turbine arranged downstream of the first, and an exhaust-gas aftertreatment system being arranged downstream of the second exhaust-gas turbine comprises, in a warm-up mode, controlling at least one exhaust-gas turbine so as to increase an inlet temperature of an exhaust-gas flow at the inlet into the exhaust-gas aftertreatment system. In this way, the exhaust-gas aftertreatment system may be rapidly heated.

An engine control method includes: a first fuel supply step of supplying fuel into the combustion chamber using an injector when a spark plug makes flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio; after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber.

A supercharging device is disclosed for an internal combustion engine having an exhaust-gas turbocharger and a fresh-air compressor. The supercharging device includes a recuperation charger which has a compressor-turbine with a high-pressure side and a low-pressure side and which has an electromechanical motor-generator coupled to the compressor-turbine. The compressor-turbine is operable at least firstly when the supercharging device is configured in a booster operating mode in a manner driven by the motor-generator as a compressor for increasing the pressure of charge-air mass flow to the intake tract of the engine, and secondly when the supercharging device is configured in a recuperation operating mode in a manner driven by the charge-air mass flow as a turbine for energy recovery by the motor-generator.

The invention relates to a method for determining the pressure P.sub.avcm upstream of a mechanical compressor (3) equipped with a double supercharging circuit of a combustion engine. The pressure P.sub.avcm is determined by a dynamic model based on a law of conservation of flow rate in the volume upstream of the mechanical compressor. The model links the pressure P.sub.avcm upstream of the mechanical compressor (3) to a temperature T.sub.avcm upstream of the mechanical compressor (3), to a boost pressure P.sub.sural and boost temperature T.sub.sural on the intake side of the engine, and to an openness Bypass of the bypass valve (4).