High pressure loop exhaust gas circulation is achieved in an exhaust system (10) of an engine (12) by providing an adjustable valve (100) in an exhaust passage (18) of the engine (12). The valve (100) is configured to control fluid flow through the passage (18) and generate pressure to drive the high pressure exhaust gas recirculation. The valve (100) includes a valve inner surface (110) that has a curvilinear profile when viewed in longitudinal cross section. An actuator (140) is connected to the valve (100), and is configured to move the valve (100) relative to the exhaust passage (18) so as to control exhaust gas pressure within the exhaust passage (18). In some embodiments, a pilot tube (280) is used in combination with the valve (100) to generate high pressure exhaust gas recirculation at the engine (12) intake.

High pressure loop exhaust gas circulation is achieved in an exhaust system (10) of an engine (12) by providing an adjustable valve (100) in an exhaust passage (18) of the engine (12). The valve (100) is configured to control fluid flow through the passage (18) and generate pressure to drive the high pressure exhaust gas recirculation. The valve (100) includes a valve inner surface (110) that has a curvilinear profile when viewed in longitudinal cross section. An actuator (140) is connected to the valve (100), and is configured to move the valve (100) relative to the exhaust passage (18) so as to control exhaust gas pressure within the exhaust passage (18). In some embodiments, a pilot tube (280) is used in combination with the valve (100) to generate high pressure exhaust gas recirculation at the engine (12) intake.

An energy recovery system for an engine system is disclosed. The engine system includes an engine, an exhaust conduit configured to receive exhaust gases discharged from the engine, and a first turbocharger coupled to the exhaust conduit to receive exhaust gases from the engine and provides compressed air to the engine. The energy recovery system includes a bypass conduit, a second turbocharger, and an accumulator. The bypass conduit is coupled to the exhaust conduit upstream of the first turbocharger, and facilitates a portion of exhaust gases from the exhaust conduit to bypass the first turbocharger. The second turbocharger is coupled to the bypass conduit, and is driven by the portion of exhaust gases bypassing the first turbocharger to compress air received from an ambient to a first pressure. The accumulator is in fluid communication with the second turbocharger, and stores air received from the second turbocharger at the first pressure.

In a non-EGR region that is a light load operating region, an EGR control valve (21) is opened at a predetermined infinitesimal opening degree M that corresponds to such infinitesimal EGR ratio as not to affect an ignition timing. With this control, since an EGR passage (20) is basically in a state in which the EGR passage (20) is filled with EGR gas, when an operating condition is changed from the non-EGR region to an EGR region and the EGR control valve (21) is opened so as to gain a target EGR ratio, a desired quantity of the EGR gas is introduced into an intake passage (2) substantially at the same time as the opening of the EGR control valve (21). An actual EGR ratio can thus follow the target EGR ratio with a good response.

In a non-EGR region that is a light load operating region, an EGR control valve (21) is opened at a predetermined infinitesimal opening degree M that corresponds to such infinitesimal EGR ratio as not to affect an ignition timing. With this control, since an EGR passage (20) is basically in a state in which the EGR passage (20) is filled with EGR gas, when an operating condition is changed from the non-EGR region to an EGR region and the EGR control valve (21) is opened so as to gain a target EGR ratio, a desired quantity of the EGR gas is introduced into an intake passage (2) substantially at the same time as the opening of the EGR control valve (21). An actual EGR ratio can thus follow the target EGR ratio with a good response.

A fuel reforming system may include an engine combusting reformed gas to generate mechanical power, an intake line connected to the engine to supply reformed gas and air to the engine, an exhaust line connected to the engine to circulate exhaust gas expelled from the engine, a fuel reformer provided at an exhaust gas recirculation (EGR) line diverging from the exhaust line, into which a fuel is injected from the EGR line, mixing the fuel injected from the EGR line and the EGR gas, and reforming the fuel mixed in the EGR gas, and a catalyst disposed in the exhaust line and purifying nitrogen oxide included in the exhaust gas at a front end portion of the fuel reformer.

An evacuator is disclosed, and includes a body defining a central axis, a converging motive section, a diverging discharge section, at least one suction port, and at least one Venturi gap. The Venturi gap is located between an outlet end of the converging motive section and an inlet end of the diverging discharge section. The evacuator also includes a fin positioned within the motive section of the body. The fin extends in the direction of the central axis.

An evacuator is disclosed, and includes a body defining a central axis, a converging motive section, a diverging discharge section, at least one suction port, and at least one Venturi gap. The Venturi gap is located between an outlet end of the converging motive section and an inlet end of the diverging discharge section. The evacuator also includes a fin positioned within the motive section of the body. The fin extends in the direction of the central axis.

An intake system may include a purge supply device; an exhaust gas recirculation device; and a pressure adjustor. The purge supply device may include a purge path connected to an intake path of an engine mounted on a vehicle, and be configured to supply evaporative fuel from a fuel tank to the intake path through the purge path. The exhaust gas recirculation device may include a circulation path connected to the intake path between a throttle valve and a first connecting position connecting the intake path and the purge path, and be configured to supply to the intake path a part of exhaust gas of the engine through the circulation path. The pressure adjustor may be disposed between the first connecting position and a second connecting position connecting the intake path and the circulation path, and be configured to adjust a pressure at the second connecting position.

Methods and systems are provided for an Exhaust Gas Recirculation (EGR) system for an internal combustion engine. In one example, the EGR system comprises an inlet air duct configured to provide the internal combustion engine with inlet air, an EGR diffuser configured to provide recirculated exhaust gases from the internal combustion engine to the inlet air duct through an outlet, and a resilient element, the EGR diffuser and resilient element adapted to provide homogenous mixing of EGR gases and inlet air at a specific operating condition of the vehicle.