A dedicated exhaust gas recirculation configuration that provides reduced exhaust gas recirculation (EGR) backflow and reduced fresh air backflow. One-way valves are positioned in the EGR loop to reduce or avoid fresh-air backflow into the dedicated exhaust gas recirculating cylinder and/or positioned in the engine intake passage to reduce or avoid dedicated cylinder exhaust gas backflow into the intake passage.

An engine system includes an engine including a plurality of engine cylinders, an intake manifold, and an exhaust manifold; and a compound turbocharger system having a first turbine driving a first compressor, and a second turbine driving a second compressor. The engine system further includes an intake line including the first compressor, the second compressor, and the at least one intake manifold; and an exhaust line including the exhaust manifold, the second turbine, and the first turbine. The engine system also includes an exhaust restriction valve located in the exhaust manifold of the engine downstream of a subset of the plurality of the engine cylinders; and an exhaust gas recirculation line having an upstream end located to receive exhaust from the subset of the plurality of engine cylinders, and a downstream end coupled to the intake line downstream the first compressor and upstream of the second compressor.

An engine system includes an engine including a plurality of engine cylinders, an intake manifold, and an exhaust manifold; and a compound turbocharger system having a first turbine driving a first compressor, and a second turbine driving a second compressor. The engine system further includes an intake line including the first compressor, the second compressor, and the at least one intake manifold; and an exhaust line including the exhaust manifold, the second turbine, and the first turbine. The engine system also includes an exhaust restriction valve located in the exhaust manifold of the engine downstream of a subset of the plurality of the engine cylinders; and an exhaust gas recirculation line having an upstream end located to receive exhaust from the subset of the plurality of engine cylinders, and a downstream end coupled to the intake line downstream the first compressor and upstream of the second compressor.

Disclosed are two system devices for stratified injecting the recirculated exhaust gas and high-specific-heat-capacity or inert gas for clean combustion of an internal combustion engine. The former is composed of an exhaust gas recirculation system, an injection system, and a power system. The latter is composed of four parts, and a high-specific-heat-capacity gas or inert gas channel is added. Injectors can be arranged at any position in the cylinder between a top dead center and a bottom dead center of a piston in a cylinder; 1-3 layers of injectors can be arranged; and 2-6 injectors can be arranged on each layer. Gas participating in combustion enters the cylinder from two intake channels, namely, a scavenging port of the internal combustion engine and the injectors; an in-cylinder swirl ratio can be remarkably increased through kinetic energy carried by the gas; and fuel-gas mixing is promoted, and the combustion rate is increased.

Disclosed are two system devices for stratified injecting the recirculated exhaust gas and high-specific-heat-capacity or inert gas for clean combustion of an internal combustion engine. The former is composed of an exhaust gas recirculation system, an injection system, and a power system. The latter is composed of four parts, and a high-specific-heat-capacity gas or inert gas channel is added. Injectors can be arranged at any position in the cylinder between a top dead center and a bottom dead center of a piston in a cylinder; 1-3 layers of injectors can be arranged; and 2-6 injectors can be arranged on each layer. Gas participating in combustion enters the cylinder from two intake channels, namely, a scavenging port of the internal combustion engine and the injectors; an in-cylinder swirl ratio can be remarkably increased through kinetic energy carried by the gas; and fuel-gas mixing is promoted, and the combustion rate is increased.

An internal combustion engine comprises a supercharger 34 having a compressor 34a and a turbine 34b and an EGR apparatus 50 having an exhaust recirculating pipe 51, an upstream EGR valve 52 and a downstream EGR valve 53. An electronic control unit 60 fully opens the upstream EGR valve 52 and controls an EGR amount by the downstream EGR valve 53 when a peak value of an exhaust pressure increases excessively. Thereby, since exhaust volume increases, the peak value of the exhaust pressure falls. Therefore, damage of parts of an exhaust system can be avoided. The electronic control unit 60 fully opens the downstream EGR valve 53 and controls the EGR amount by the upstream EGR valve 52 when the peak value of the exhaust pressure decreases excessively. Thereby, since the exhaust volume decreases, the peak value of the exhaust pressure rises. Therefore, supercharging can be continued while an EGR gas is being introduced.

An internal combustion engine comprises a supercharger 34 having a compressor 34a and a turbine 34b and an EGR apparatus 50 having an exhaust recirculating pipe 51, an upstream EGR valve 52 and a downstream EGR valve 53. An electronic control unit 60 fully opens the upstream EGR valve 52 and controls an EGR amount by the downstream EGR valve 53 when a peak value of an exhaust pressure increases excessively. Thereby, since exhaust volume increases, the peak value of the exhaust pressure falls. Therefore, damage of parts of an exhaust system can be avoided. The electronic control unit 60 fully opens the downstream EGR valve 53 and controls the EGR amount by the upstream EGR valve 52 when the peak value of the exhaust pressure decreases excessively. Thereby, since the exhaust volume decreases, the peak value of the exhaust pressure rises. Therefore, supercharging can be continued while an EGR gas is being introduced.

A method for operating an internal combustion engine includes operating at least one cylinder pre-chamber in a homogeneous charge compression ignition (HCCI) combustion mode by providing an air/fuel mixture in the pre-chamber that is fluidly connected to the at least one engine cylinder, creating H and OH radicals in the pre-chamber to achieve an ignition in the at least one pre-chamber, determining whether an ignition timing is advanced or delayed relative to a desired timing, and delaying the ignition when the ignition is advanced relative to the desired timing by cooling the pre-chamber and the at least one engine cylinder.

An exhaust gas control apparatus of an internal combustion engine includes a turbocharger including a turbine in an exhaust passage of the internal combustion engine, a post-processing device configured to control exhaust gas, the post-processing device being disposed in the exhaust passage downstream of the turbine, an EGR passage configured to connect the exhaust passage downstream of the turbine and upstream of the post-processing device with a cylinder of the internal combustion engine, and an EGR device including an EGR valve which is disposed in an end portion on the cylinder side of the EGR passage and opens or closes the EGR passage in the cylinder.

A dedicated exhaust gas recirculation configuration that provides reduced exhaust gas recirculation (EGR) backflow and reduced fresh air backflow. One-way valves are positioned in the EGR loop to reduce or avoid fresh-air backflow into the dedicated exhaust gas recirculating cylinder and/or positioned in the engine intake passage to reduce or avoid dedicated cylinder exhaust gas backflow into the intake passage.