Ducting is described. The ducting is for use with: a high pressure turbocharger (HPT) having a HPT exhaust gas outlet, and a low pressure turbocharger (LPT) having an LPT exhaust gas inlet. The ducting comprises first and second ducts (LPT). The first duct has a first duct inlet that is connectable to the HPT exhaust gas outlet and a first duct outlet that is connectable to the LPT exhaust gas inlet. The second duct has a second duct inlet for wastegate gases from a wastegate of the and a second duct outlet located within the first duct. The second duct comprises an elongate second duct portion which is a length of the second duct located within the first duct. The second duct portion comprises the second duct outlet and is arranged such that the second duct outlet is pointed towards the first duct outlet.

Methods and systems are provided for controlling a power output of a power source using a fluidic variable turbine turbocharger. In one example, a turbocharger system coupled to the power source includes a first turbocharger having a first compressor and a first turbine, and a second turbocharger having a second compressor and a second turbine, where boost air from the second compressor is directed to only a nozzle of the first turbine.

A bypass valve assembly for a turbocharger includes a bypass valve having a valve stem rotatable about a valve stem axis for opening and closing the valve. The end of a first crank of an articulated two-bar linkage is connected to the valve stem. The end of a second crank of the linkage is connected to a cam follower engaged with a guide cam. An actuator provides motive force to the cam follower to proceed along the guide cam, which is configured to advance the cam follower along a guide path that is non-linear and non-circular arc, causing the two-bar linkage to rotate the valve stem. Valve stem angular displacement versus actuator stroke can be altered by modification of the shape of the guide path.

A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T.sub.1 through an inlet of a compressor having a pressure ratio of PR.sub.GT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature T.sub.BIC to a temperature T.sub.AIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio r.sub.VC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ${\left({\mathrm{PR}}_{\mathrm{GT}}\right)}^a{\left(r_{\mathrm{VC}}\right)}^b\left(\frac{T_{\mathrm{AIC}}}{T_{\mathrm{BIC}}}\right)\left(\frac{T_1}{T_A}\right)<1.$
An engine assembly is also discussed.

An object is to provide a supercharging system capable of actively and easily controlling a rotational speed of a turbine generator. A supercharging system includes a compressor driven by an electric motor to pump fluid to an engine, a turbine generator rotated by exhaust from the engine, and a drive device that drives the electric motor by electricity generated by the turbine generator, wherein the drive device includes a rectifying unit that rectifies the electricity generated by the turbine generator, a converter unit that steps up or down a voltage value of a DC voltage rectified by the rectifying unit and outputs the DC voltage, an inverter unit that drives the electric motor using the DC voltage output from the converter unit, and a control unit that controls a change amount of the DC voltage in the converter unit.

The invention relates to a compressor for inducting an internal combustion engine, comprising an electric motor (3) for driving a first compressor wheel (4), wherein, in at least one operating state, an inlet-side, first gas flow (5a) of the internal combustion engine (1) is compressed by the compressor (2), wherein the compressor (2) comprises a first compressor path (5) for the first gas flow (5a) and a second compressor path (6) for a second gas flow (6a), wherein the second gas flow (6a), in particular, in at least one operating state, opens into an exhaust gas flow (8) of the internal combustion engine (1) as a secondary air flow (6a).

Methods and systems are provided for controlling a power output of a power source using a fluidic variable turbine turbocharger. In one example, a turbocharger system coupled to the power source includes a first turbocharger having a first compressor and a first turbine, and a second turbocharger having a second compressor and a second turbine, where boost air from the second compressor is directed to only a nozzle of the first turbine.

The power system includes a compression ignition engine configured to combust intake gas; an intake arrangement configured to intake charge air; an exhaust arrangement to receive a first portion of the exhaust; an EGR arrangement to receive a second portion of the exhaust as EGR gas; a first mixer to selectively mix a first portion of the EGR gas and the charge air as mixed gas; an intake heat exchanger positioned upstream or downstream of the first mixer and respectively configured to receive one of the intake charge air or the mixed gas such that heat is exchanged with engine coolant; a second mixer positioned downstream of the first mixer and the intake heat exchanger and configured to selectively mix a second portion of the EGR gas and the mixed gas to form the intake gas; and an intake manifold configured to direct the intake gas into the engine.

A turbocharging assembly is described. The turbocharging assembly includes a housing having a first housing part for enclosing a first stage, particularly a low-pressure stage, comprising a first turbine coupled with a first compressor, particularly a low-pressure turbine coupled with a low-pressure compressor, and a second housing part for enclosing a second stage, particularly a high-pressure stage. The second housing part encases an exhaust gas passage unit replacing a second turbine, particularly a high-pressure turbine, the exhaust gas passage unit being an insert configured for providing a gas passage from an exhaust gas inlet provided in the second housing part to the first turbine. Further, a method of operating a multi-stage turbocharging assembly as single-stage turbocharger is described.

An engine system includes an engine with an intake manifold and an exhaust manifold, a turbocharger including a turbine in communication with the exhaust manifold and a compressor in communication with the intake manifold, and a regulator configured to control a flow of exhaust gas through the turbine. A controller of the engine system is operably connected with the regulator and is configured to monitor an engine load and an exhaust gas temperature during operation of the engine, identify a proscribed engine NOx emissions level based on the engine load and the exhaust gas temperature and, when the proscribed engine NOx emissions level is identified, modify the flow of exhaust gas through the turbine to reduce the energy extracted from the exhaust gas by the turbine and reduce a drive power provided to the compressor, thereby reducing a flow of intake air provided to the intake manifold by the compressor.