An exhaust valve comprises a tubular body extending along an axis, and defining a flow section perpendicular to the axis, a flap arranged in the tubular body across the flow section, and a shaft rigidly connected to the flap. The shaft is rotatable between a closed orientation in which the flap closes the flow section and an open orientation in which the flap frees the flow section. A proximal, respectively distal, housing is rigidly connected to the tubular body and houses a proximal, respectively distal, bearing ensuring a rotary interface between the tubular body and a proximal, respectively distal, end of the shaft. A rotary actuator is capable of moving the shaft alternately between the closed orientation and the open orientation, and is arranged outside the tubular body and rigidly connected to the proximal end of the shaft. The proximal and/or distal housing is separate from the tubular body.

A fuel ejector assembly includes a nozzle structured to receive fuel from a fuel conduit and eject the fuel therethrough, and an exhaust gas recirculation (“EGR”) conduit structured to communicate a recirculated exhaust gas therethrough. A mixing portion is disposed downstream of the nozzle and the EGR conduit, the nozzle and the EGR conduit fluidly coupled to the mixing portion such that the mixing portion receives each of the fuel and the recirculated exhaust gas. A diffuser is disposed downstream of the mixing portion and is configured to be fluidly coupled to an engine to communicate a mixture of the fuel and the recirculated exhaust gas to the engine.

An Exhaust Gas Recirculation (EGR) system for an engine system is provided. The EGR system includes an exhaust gas treatment module positioned upstream of an EGR cooler with respect to an exhaust gas flow direction. The exhaust gas treatment module is in selective fluid communication with an exhaust gas line of an engine. The EGR system also includes a bypass line in selective fluid communication with the exhaust gas line of the engine. The EGR system further includes a valve arrangement configured to route an exhaust gas flow through at least one of the exhaust gas treatment module and the bypass line.

A method for control and/or regulation of a hybrid powertrain of a motor vehicle, wherein exhaust gas is taken from an exhaust system and delivered to a fresh air supply of an internal combustion engine, wherein the residual recirculated exhaust gas is purged from the fresh air supply in the event of a negative load jump. After the negative load jump, the internal combustion engine continues to run with a smaller load and simultaneously the torque supplied by the internal combustion engine is recuperated by means of the electric machine, wherein no positive torque in total is applied to the output of the powertrain.

Various embodiments include methods for determining the efficiency of an SCR catalytic converter in a system including a nitrogen oxide sensor, and a metering device for a reducing agent arranged in an exhaust-gas duct, and an exhaust recirculation line with a recirculation valve disposed downstream of the SCR catalytic converter and feeding an intake region of the engine. The methods comprise: setting or identifying a quasi-steady-state operating state and an associated recirculation rate; adding a first quantity of reducing agent using the metering device; measuring a resulting first nitrogen oxide value using the sensor; adding a further predefined quantity, different from the first quantity; measuring the resulting nitrogen oxide values using the sensor; and determining the efficiency of the SCR catalytic converter based at least in part on the associated exhaust-gas recirculation rate and the measured nitrogen oxide values.

Methods and systems are provided for calibrating an effective area associated with an exhaust gas recirculation valve and/or a variable orifice associated with the exhaust gas recirculation valve. In one example, a method may include attaining a first steady-state intake pressure with the exhaust gas recirculation valve closed, determining a second steady-state intake pressure and a differential pressure across the variable orifice with the exhaust gas recirculation valve open, and estimating the variable orifice effective area based on the second steady-state intake pressure and the differential pressure. In this way, a calibration table may be updated for an exhaust gas recirculation control apparatus that includes an exhaust gas recirculation valve and a variable orifice, such that an actual amount of recirculated exhaust gas reflects a commanded amount.

Various embodiments include methods for determining the efficiency of an SCR catalytic converter in a system including a nitrogen oxide sensor, and a metering device for a reducing agent arranged in an exhaust-gas duct, and an exhaust recirculation line with a recirculation valve disposed downstream of the SCR catalytic converter and feeding an intake region of the engine. The methods comprise: setting or identifying a quasi-steady-state operating state and an associated recirculation rate; adding a first quantity of reducing agent using the metering device; measuring a resulting first nitrogen oxide value using the sensor; adding a further predefined quantity, different from the first quantity; measuring the resulting nitrogen oxide values using the sensor; and determining the efficiency of the SCR catalytic converter based at least in part on the associated exhaust-gas recirculation rate and the measured nitrogen oxide values.

Methods and systems are provided for calibrating an effective area associated with an exhaust gas recirculation valve and/or a variable orifice associated with the exhaust gas recirculation valve. In one example, a method may include attaining a first steady-state intake pressure with the exhaust gas recirculation valve closed, determining a second steady-state intake pressure and a differential pressure across the variable orifice with the exhaust gas recirculation valve open, and estimating the variable orifice effective area based on the second steady-state intake pressure and the differential pressure. In this way, a calibration table may be updated for an exhaust gas recirculation control apparatus that includes an exhaust gas recirculation valve and a variable orifice, such that an actual amount of recirculated exhaust gas reflects a commanded amount.

An internal combustion engine inducts no air from outside atmosphere and it discharges no gas into outside environment. The engine receives hydrocarbon fuel and oxygen, and its combustion gas consists mostly of carbon dioxide and water vapor. Carbon dioxide is captured, stored and subsequently sequestered by using it with water to create a hydrocarbon fuel that can be supplied back to the engine. In that way, the engine fuel is repeatedly regenerated and reused, and the engine operates in a carbon neutral mode of operation. Some of the combustion gas is used as a diluent gas in the engine. High specific heat and high density of that gas permit operation in high-efficiency overexpanded cycle without an increase in the engine size. Various methods of the engine control and operation are described, including methods to reduce pumping loss. Various modes of in-cylinder diluent gas formation are considered.

A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; an octane number determination unit for determining whether fuel injected from the fuel injection valve has a prescribed octane number; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion occurs within the cylinder. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a case where fuel is determined to have a prescribed octane number, when fuel is determined not to have a prescribed octane number.