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.

A negative pressure control valve (44) is disposed in a part of an intake passage (12) upstream of a confluence (30) of an EGR passage (27) and the intake passage (12). When in an EGR region (Regr) where an EGR gas is recirculated to the intake passage (12) through the EGR passage (27), the negative pressure control valve (44) is controlled in a manner to ensure a differential pressure between an exhaust passage (13) and the intake passage (12). When in an operation region (R2) lower in load than the EGR region (Regr), the negative pressure control valve (44) is controlled in a closing direction so as to suppress occurrence of noise.

A negative pressure control valve (44) is disposed in a part of an intake passage (12) upstream of a confluence (30) of an EGR passage (27) and the intake passage (12). When in an EGR region (Regr) where an EGR gas is recirculated to the intake passage (12) through the EGR passage (27), the negative pressure control valve (44) is controlled in a manner to ensure a differential pressure between an exhaust passage (13) and the intake passage (12). When in an operation region (R2) lower in load than the EGR region (Regr), the negative pressure control valve (44) is controlled in a closing direction so as to suppress occurrence of noise.

Provided herein is internal combustion engine system including: an internal combustion engine; a turbocharger turbine operatively connected to a turbocharger compressor; an air intake system; an exhaust gas system; an exhaust gas recirculation (EGR) conduit; an EGR valve; and a turbomachine arranged in the EGR conduit. Further, the EGR valve and the turbomachine are positioned in relation to each other in the EGR conduit such that a flow of high pressure exhaust gas through the EGR conduit towards the air intake system reaches the EGR valve before reaching the turbomachine; an additional exhaust gas conduit is arranged between the EGR conduit and a point of the exhaust system downstream the turbocharger turbine so as to allow exhaust gas to flow.

Multiple convergent nozzles define multiple flow passages in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzles each converge toward the outlet of the mixer. An exhaust gas housing includes an exhaust gas inlet leading into an interior of the exhaust gas housing. Multiple convergent-divergent nozzles each correspond to one of the plurality of convergent nozzles. The convergent-divergent nozzles each include an air-exhaust gas inlet in fluid communication to receive fluid flow from a corresponding convergent nozzle and the interior of the exhaust gas housing.

Methods and system are provided for indicating whether a variable orifice valve positioned in a fuel vapor recovery line of a vehicle fuel system is degraded. In one example, a method may include actively manipulating a pressure in the fuel system during a refueling event, and indicating whether the variable orifice valve is degraded based on a loading rage of a fuel vapor storage canister with fuel vapors while the pressure is actively manipulated. In this way, it may be determined as to whether the variable orifice valve is stuck in a high-flow or a low-flow position such that mitigating action may be taken to reduce or avoid release of undesired evaporative emissions to atmosphere.

Methods and system are provided for indicating whether a variable orifice valve positioned in a fuel vapor recovery line of a vehicle fuel system is degraded. In one example, a method may include actively manipulating a pressure in the fuel system during a refueling event, and indicating whether the variable orifice valve is degraded based on a loading rage of a fuel vapor storage canister with fuel vapors while the pressure is actively manipulated. In this way, it may be determined as to whether the variable orifice valve is stuck in a high-flow or a low-flow position such that mitigating action may be taken to reduce or avoid release of undesired evaporative emissions to atmosphere.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

Techniques for controlling a forced-induction engine having a low pressure cooled exhaust gas recirculation (LPCEGR) system comprise determining a target boost device inlet pressure for each of one or more systems that could require a boost device inlet pressure change as part of their operation and boost device inlet pressure hardware limits for a set of components in the induction system, determining a final target boost device inlet pressure based on the determined sets of target boost device inlet pressures and boost device inlet pressure hardware limits, and controlling a differential pressure (dP) valve based on the final target boost device inlet pressure to balance (i) competing boost device inlet pressure targets of the one or more systems and (ii) the set of boost device inlet pressure hardware limits in order to optimize engine performance and prevent component damage.

A method of determining an abnormality of a differential pressure sensor which is configured to detect a pressure differential between an upstream side and a downstream side of an EGR valve provided to an EGR passage of an engine, is provided. The method includes the steps of controlling an opening of the EGR valve based on an output value of the differential pressure sensor, determining the abnormality of the differential pressure sensor based on the output value of the differential pressure sensor, controlling at least a throttle valve of the engine toward a closed side so that the pressure differential is maintained at a given pressure or higher when determining, and prohibiting the execution of the abnormality determination when an engine speed is a given engine speed or higher, and permitting the execution of the abnormality determination when the engine speed is less than the given engine speed.