Methods and systems are provided for determining changes in a flow area of an exhaust gas recirculation (EGR) valve for EGR flow estimates due to a change in temperature difference between a stem and body of the EGR valve. In one example, a method includes adjusting an EGR valve based on an estimate of EGR flow, the EGR flow estimated based on a pressure difference across the EGR valve and an adjusted valve flow area. The adjusted valve flow area may be based on the temperature difference between the stem and body of the EGR valve.

A controller includes a forced-induction-device controlling section, an obtaining section that is configured to repeatedly obtain a temperature of the coolant in the intake-air cooling system, a determining section that is configured to determine whether the temperature obtained by the obtaining section is higher than or equal to a forced-induction limiting control starting temperature. On condition that the temperature of the coolant has risen to a value at which the determining section determines that the temperature obtained by the obtaining section is higher than or equal to the forced-induction limiting control starting temperature, the forced-induction-device controlling section starts a forced-induction limiting control to lower a forced-induction pressure. In the forced-induction limiting control, the forced-induction-device controlling section increases an extent of limiting of the forced induction as the temperature obtained by the obtaining section becomes closer to the boiling point.

A control apparatus for an internal combustion engine that includes an EGR channel and an EGR valve is configured, when the internal combustion engine is in a warm-up process and when an intake air flow rate that is a flow rate of air supplied to the internal combustion engine main body is less than or equal to a predetermined value, to open the EGR valve with a minute opening degree that is an opening degree smaller than a minimum opening degree of the EGR valve with which a condensed water in an exhaust-channel-side portion that is a portion of the EGR channel on a side closer to the exhaust channel relative to the EGR valve flows into an intake-channel-side portion that is a portion of the EGR channel on a side closer to the intake channel relative to the EGR valve.

A system and method to perform bypass actuation detection includes alternating control of a bypass valve within an exhaust gas recirculation (EGR) system of a vehicle to direct flow of gas through a cooler module or a bypass module within the EGR system. The method also includes determining a position of an EGR valve that directs the gas into the EGR system, and verifying operation of the bypass valve based on the position of the EGR valve.

An EGR control device includes: a drive unit, a basic opening degree deriving unit, a measurement unit, a memory unit, a correction opening degree deriving unit and a control unit. The drive unit varies an opening degree of an EGR valve. The basic opening degree deriving unit derives a basic EGR valve opening degree based on an operating condition of an engine. The measurement unit measures a temperature in the downstream side of a position of where EGR gas is recirculated in an intake passage. In the memory unit, information acquired in advance is stored. The information indicates a relationship between the opening degree and a temperature difference. The correction opening degree deriving unit derives a correction opening degree with reference to the information. The control unit controls the drive unit such that the opening degree of the EGR valve becomes a target EGR valve opening degree by correcting the basic EGR valve opening degree with the correction opening degree.

An internal combustion engine system includes a first EGR valve to control flow in a first flow path, and a second EGR valve to control flow in a second flow path. A temperature sensor is disposed in the exhaust gas feedstream upstream of the exhaust purifying device, and a controller is in communication with the internal combustion engine and the temperature sensor and is operatively connected to the first and second EGR valves. The controller executes a routine to monitor the temperature of the exhaust gas feedstream upstream of the exhaust purifying device and control the first valve to control flow of exhaust gas to the air intake system via the first flow path and control the second valve to control flow of exhaust gas to the air intake system via the second flow path based upon the temperature of the exhaust gas feedstream upstream of the exhaust purifying device.

A thermal energy management system for an internal combustion engine of a motor vehicle includes a coolant circuit including the internal combustion engine and a first heat exchanger. The coolant circuit is configured to convey a coolant therethrough. The thermal energy management system includes a gas circuit including the internal combustion engine, the first heat exchanger, and an exhaust line configured to convey an exhaust gas produced by the engine from the gas circuit. The first heat exchanger exchanging heat energy between the coolant flowing through the coolant circuit and the exhaust gas flowing through the gas circuit.

A method and system for operating an internal combustion engine equipped with a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger is disclosed. A value of a parameter indicative of a temperature of an exhaust gas is determined, and an internal recirculation strategy of the exhaust gas is actuated if the determined value is lower than a predetermined threshold value thereof. The internal recirculation strategy includes interrupting a flowing of exhaust gas through the exhaust gas recirculation pipe, and opening an exhaust valve during an intake stroke of a piston of the internal combustion engine.

Optimum fuel consumption and a stable combustion state are obtained by performing control to keep ignition always at an optimum timing such that ignition timing becomes MBT, without changing an EGR amount or an EGR rate that can realize the optimum fuel consumption rate. Therefore, in an internal combustion engine control device for controlling an internal combustion engine connected with a humidity sensor configured to detect humidity in an atmosphere and an ignition device configured to ignite an air-fuel mixture in a combustion chamber, the internal combustion engine control device includes a moisture amount calculation part configured to calculate an amount of moisture contained in intake air flowing into the combustion chamber according to a detection value of the humidity sensor; and an ignition timing control part configured to control ignition timing of the ignition device. In the internal combustion engine control device, the ignition timing control part controls the ignition timing of the ignition device so as to move in an advance direction as the amount of moisture in intake air calculated by the moisture amount calculation part increases.

Various systems and methods are provided for exhaust gas recirculation. In one example, an exhaust gas recirculation (EGR) system includes an EGR passage coupling an engine exhaust system to an engine intake system, a first EGR cooler positioned in the EGR passage, the first EGR cooler configured to cool EGR with a first fluid, and a second EGR cooler positioned in the EGR passage downstream of the first EGR cooler, the second EGR cooler configured to cool EGR with a second fluid.