The invention relates to an internal combustion engine system (100), comprising: —an internal combustion engine (2) comprising a cylinder block (3) housing a plurality of cylinders (4), a first intake manifold (6a) connected to a first group of cylinders (4a) a second distinct intake manifold (6b) connected to a second group of cylinders (4b) and a first, respectively a second, exhaust manifold (8a, 8b) for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders (4a, 4b); —an air inlet line (10); —an EGR line (20) connected to the first and second exhaust manifolds (8a, 8b); wherein the internal combustion engine system is operable in at least two operating modes, respectively a normal operating mode in which all cylinders are supplied with fuel and a regeneration operating mode, in which the cylinders of the first group of cylinders (4a) are no longer supplied with fuel, characterized in that: —the system also includes a mixing unit (30) comprising a four-way valve, said four-way valve (30) having a first inlet (31) connected to the EGR line (20), a second inlet (32) connected to the air inlet line (10), a first outlet (33) connected to the first intake manifold (6a) and a second outlet (34) connected to the second intake manifold (6b); —the four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold (6a) and to the second intake manifold (6b) have approximately the same proportion of exhaust gas and so that, in said regeneration operating mode, the intake gas supplied to the first intake manifold (6a) only includes exhaust gas.

The invention relates to an internal combustion engine system (100), comprising: —an internal combustion engine (2) comprising a cylinder block (3) housing a plurality of cylinders (4), a first intake manifold (6a) connected to a first group of cylinders (4a) a second distinct intake manifold (6b) connected to a second group of cylinders (4b) and a first, respectively a second, exhaust manifold (8a, 8b) for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders (4a, 4b); —an air inlet line (10); —an EGR line (20) connected to the first and second exhaust manifolds (8a, 8b); wherein the internal combustion engine system is operable in at least two operating modes, respectively a normal operating mode in which all cylinders are supplied with fuel and a regeneration operating mode, in which the cylinders of the first group of cylinders (4a) are no longer supplied with fuel, characterized in that: —the system also includes a mixing unit (30) comprising a four-way valve, said four-way valve (30) having a first inlet (31) connected to the EGR line (20), a second inlet (32) connected to the air inlet line (10), a first outlet (33) connected to the first intake manifold (6a) and a second outlet (34) connected to the second intake manifold (6b); —the four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold (6a) and to the second intake manifold (6b) have approximately the same proportion of exhaust gas and so that, in said regeneration operating mode, the intake gas supplied to the first intake manifold (6a) only includes exhaust gas.

The present invention relates to an intake system for natural gas engine. An intake system for an engine is provided. A conduit is configured to direct a combustible mixture to a cylinder head. A mixing unit is coupled to the conduit. The mixing unit includes a fuel doser configured to dispense fuel into the conduit and a first mixer positioned downstream of the fuel doser. The first mixer is configured to mix air and the fuel. The mixing unit further includes a exhaust gas doser configured to dispense exhaust gas into the conduit and a second mixer positioned downstream of the exhaust gas doser. The second mixer is configured to mix the exhaust gas with the air and the fuel to make the combustible mixture. An air intake throttle is configured to direct the air into the mixing unit.

Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

The invention relates to an internal combustion engine system. The system includes a mixing unit comprising a four-way valve. The four-way valve having a first inlet connected to the EGR line, a second inlet connected to the air inlet line, a first outlet connected to the first intake manifold and a second outlet connected to the second intake manifold. The four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold and to the second intake manifold have approximately the same proportion of exhaust gas and fresh air and so that, in said cylinder deactivation mode, the intake gas supplied to the first intake manifold only includes exhaust gas and the fresh air is directed exclusively to the second intake manifold.

A method for operating an oxycombustion engine system includes passing a nitrogen-depleted gas, a fuel, and a recycled exhaust gas into a combustion chamber, combusting a mixture of the nitrogen-depleted gas, the fuel, and the recycled exhaust gas, thereby producing an exhaust gas including carbon dioxide, detecting a pressure of the recycled exhaust gas passed to the combustion chamber, determining whether the detected pressure of the recycled exhaust gas is less than a configurable pressure threshold, and in response to determining that the detected pressure of the recycled exhaust gas is less than the configurable pressure threshold, increasing the pressure of the recycled exhaust gas passed to the combustion chamber.

A method for operating an oxycombustion engine system includes passing a nitrogen-depleted gas, a fuel, and a recycled exhaust gas into a combustion chamber, combusting a mixture of the nitrogen-depleted gas, the fuel, and the recycled exhaust gas, thereby producing an exhaust gas including carbon dioxide, detecting a pressure of the recycled exhaust gas passed to the combustion chamber, determining whether the detected pressure of the recycled exhaust gas is less than a configurable pressure threshold, and in response to determining that the detected pressure of the recycled exhaust gas is less than the configurable pressure threshold, increasing the pressure of the recycled exhaust gas passed to the combustion chamber.

An exhaust gas recirculation system for an engine includes a conduit, and a U-shaped exhaust gas mixer. The conduit is configured to direct an exhaust gas away from an exhaust manifold. The U-shaped exhaust gas mixer is configured to direct exhaust gas from the conduit and into an engine air intake system. The U-shaped exhaust gas mixer is arranged with a pre-mixing cavity configured to disperse the exhaust gas and entraining the exhaust gas into an intake air flow prior to distribution into an intake manifold of an engine.

To solve the problems of compressor wheel blade flow separation causing surge type noises when an exhaust gas recirculation (EGR) duct introduces into the compressor exhaust gases to be returned to the engine, the exhaust gas is fed into an annular volume, defined between inner and outer walls or an annular transition cavity shaped as a radially expanded, axially flattened cylindrical space in the compressor inlet, so that the generally unidirectional radial flow from an EGR duct is re-directed and organized as it is turned from generally radial to generally axial, merging with the general inlet flow and presenting the compressor wheel with airflow of “circumferentially uniform” flow velocity.

To solve the problems of compressor wheel blade flow separation causing surge type noises when an exhaust gas recirculation (EGR) duct introduces into the compressor exhaust gases to be returned to the engine, the exhaust gas is fed into an annular volume, defined between inner and outer walls or an annular transition cavity shaped as a radially expanded, axially flattened cylindrical space in the compressor inlet, so that the generally unidirectional radial flow from an EGR duct is re-directed and organized as it is turned from generally radial to generally axial, merging with the general inlet flow and presenting the compressor wheel with airflow of “circumferentially uniform” flow velocity.