Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

Various embodiments include a method of operating a diesel engine having an exhaust tract and an SCR-combined diesel particulate filter in the exhaust tract, wherein an aqueous urea solution is introduced into the exhaust tract, and an exhaust gas recirculation apparatus having an exhaust gas recirculation conduit branching off downstream of the SCR-combined diesel particulate filter for performing a low-pressure exhaust gas recirculation comprising: measuring an NH.sub.3 concentration in exhaust gas downstream of the SCR-combined diesel particulate filter; and upon exceeding a threshold value of the measured NH.sub.3 concentration, reducing the low-pressure exhaust gas recirculation rate based at least in part on the measured NH.sub.3 concentration.

An internal combustion engine includes combustion chambers, each having a first intake port, and first and second exhaust ports. An intake manifold is connected to the first intake port of each combustion chamber, a main pressure booster upstream of the intake manifold. An exhaust discharge arrangement includes a main exhaust manifold connected to the first exhaust port of each combustion chamber, the exhaust discharge arrangement connected to the second exhaust port of a first subset combustion chambers, and an exhaust recirculation manifold connected to the second exhaust port of a second subset combustion chambers and connected to an upstream side of the main pressure booster. The engine operates in high load and low load modes, which vary how the engine evacuates the exhaust gas of the second subset combustion chambers to the exhaust recirculation manifold. A related method is also disclosed.

A method of operating an engine includes igniting a combustible mixture in a combustion chamber of the engine, which produces exhaust gases. The exhaust gases are ejected into an exhaust manifold of the engine to create a primary exhaust stream. A portion of the exhaust gases is separated from the primary exhaust stream to create a secondary exhaust stream. Air and fuel are then mixed with the secondary exhaust stream to form a reformer feed mixture. The reformer feed mixture is reacted in a catalytic reformer to create a reformate exhaust stream, which is then mixed with an intake air stream to create a mixed air stream. The mixed air stream is the fed to the combustion chamber of the engine as the combustible mixture.

An exhaust gas conduction system for a gasoline engine comprises an exhaust gas line and an intake line which can be connected to an intake manifold, a charge air compressor arranged in the intake line, and a turbine arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve. At least one exhaust gas recirculation line with an EGR throttle valve is provided. At least one particle filter is arranged in the bypass line and an exhaust gas valve is provided in the exhaust gas line.

An exhaust gas conduction system for a gasoline engine comprises an exhaust gas line and an intake line which can be connected to an intake manifold, a charge air compressor arranged in the intake line, and a turbine arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve. At least one exhaust gas recirculation line with an EGR throttle valve is provided. At least one particle filter is arranged in the bypass line and an exhaust gas valve is provided in the exhaust gas line.

A start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle. An internal combustion engine is in fluid communication with an exhaust aftertreatment system having an exhaust. An SCR module is disposed in the exhaust passage downstream of the engine and an electric motor. The method includes operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode.

A start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle. An internal combustion engine is in fluid communication with an exhaust aftertreatment system having an exhaust. An SCR module is disposed in the exhaust passage downstream of the engine and an electric motor. The method includes operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode.

Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.