Abstract: The present disclosure refers to a turbocharged internal combustion engine with exhaust gas recycling, comprising an intake manifold, an exhaust manifold, a fresh air turbocharger and an exhaust supercharger, wherein the intake manifold is divided by a separating wall into a fresh air passage and an exhaust passage, one of the passages being connected to inlet openings of cylinders of the engine, the fresh air passage being connected to the outlet of the compressor of the fresh air turbocharger, the exhaust passage being connected to the outlet of the compressor of the exhaust supercharger and the separating wall being formed with orifices connecting the two passages.

Abstract: An arrangement for injecting a reducing agent into an exhaust line of a combustion engine (1). An exhaust line (3) leads exhaust gases from the engine. A first turbine (4) is in the exhaust line (3). A second turbine (20) in the exhaust line is downstream of the first turbine (4) in the intended direction of flow in the exhaust line. An injector (19) injects reducing agent into the exhaust line (3) so that it is warmed and vaporized by the warm exhaust gases in the exhaust line (3), and an SCR catalyst (29). The injector (19) is in the exhaust line downstream of the first turbine (4) and upstream of the second turbine (20).

Abstract: A fresh gas supply device for an internal combustion engine having an exhaust gas turbocharger includes a charge air inlet for letting in compressed charge air from the exhaust gas turbocharger; an outlet connected to the charge air inlet, wherein the connection is closable via at least one backflow flap pivotable about a rotational flap axis; a compressed air inlet for letting compressed air into the outlet; an adjusting unit for adjusting the at least one backflow flap; at least one additional turbocharging unit having an air turbine and a compressor coupled thereto. The air turbine is disposed upstream of the compressed air inlet in the flow direction of the compressed air and compressed air can flow through the air turbine. The compressor is designed to take in and compress additional charge air from the charge air inlet and deliver compressed additional charge air to the outlet.

Abstract: Methods and systems are provided for adjusting intake airflow through two parallel induction passages. In response to increased torque demand, intake airflow may be directed through a first induction passage including an exhaust-driven turbocharger compressor and through a second induction passage including an electric compressor. Further, after the turbocharger compressor increases speed, intake airflow may be directed again through the first induction passage to further increase boost.

Abstract: Methods and systems are provided for adjusting intake airflow through two induction passages. In response to increased torque demand, intake airflow may be directed through a first induction passage including an exhaust-driven turbocharger compressor and through a second induction passage including an electric compressor. Further, after the turbocharger compressor increases speed, intake airflow may be directed again through the first induction passage to further increase boost.

Abstract: A method of controlling fuel delivery to an engine includes providing a fuel atomizer, a mechanically driven air compressor, a start up air source, and an air valve coupled between the mechanically driven air compressor and the start up air source, charging the start up air source, delivering compressed air from the start up air source to the fuel atomizer, starting the engine using an air/fuel mixture provided by the fuel atomizer, and operating the air valve to direct compressed air from the mechanically driven air compressor to the fuel atomizer after the engine starts.

Abstract: A turbocharger including a turbine wheel having a hub-to-tip ratio of no more than 60% and blades with a high turning angle, a turbine housing forming an inwardly spiraling primary-scroll passageway that significantly converges to produce highly accelerated airflow into the turbine at high circumferential angles, and a two-sided parallel compressor. The compressor and turbine each produce substantially no axial force, allowing the use of minimal axial thrust bearings. The bearing housing forms a shroud for the internal side of the compressor wheel.

Abstract: Multi-stage compressors for compressing and/or liquefying gases are disclosed herein. A multi-stage compressor in accordance with a particular embodiment includes a cylinder bank having a plurality of cylinders. A first insert having a first inside diameter can be positioned within a first individual cylinder, and a second insert having a second inside diameter, smaller than the first inside diameter, can be positioned within a second individual cylinder. A first compression piston can be positioned within the first individual cylinder to compress the gas to a first volume and a second compression piston can be positioned within the second individual cylinder to compress the gas to a second volume, smaller than the first volume.

Abstract: An assembly for controlling air flow to an engine includes a first supercharger(20) and a second supercharger (22). The superchargers are arranged in parallel with one another and in series with the throttle (70) in the air flow to the engine cylinders, and are configured to be operatively connectable with the engine upstream in the air flow to the cylinders. The assembly includes a load device (38) selectively connectable to the first supercharger (20) and selectively alternately operable to provide energy to or receive energy from the first supercharger. The superchargers are configured to be separately selectively operatively connectable with the throttle and the crankshaft to enable different modes of operation.

Abstract: A supercharger control device for an internal combustion engine is preferably applied to a system having a first supercharger and a second supercharger. A switching supercharging pressure setting unit sets a switching supercharging pressure used in case of switching a mode for operating the first supercharger and the second supercharger, based on a difference between a target supercharging pressure and an actual supercharging pressure. When the actual supercharging pressure reaches the switching supercharging pressure, a switching control unit performs a control of switching the mode. Therefore, it becomes possible to appropriately prevent the overshoot of the supercharging pressure at the time of switching the mode.

Abstract: The disclosure relates to a method for controlling a turbocharger system of an internal combustion engine. The method comprises controlling a first bypass valve of a high pressure exhaust gas turbine and a second bypass valve of a low pressure gas turbine on the basis of a turbine model, the first and second bypass valves continuously variable. In this way, turbocharger system efficiency may be maximized.

Abstract: A natural gas compression system is provided. The system may include a natural gas compressor configured to compress, and thereby pump, natural gas through a pipeline. The system may also include a natural gas burning engine, operatively coupled to the gas compressor, the engine being supplied with air by an induction system. The induction system may include a supercharger driven by the engine and configured to compress intake air and a turbocharger downstream from the supercharger and driven by exhaust gases produced by the engine. The induction system may also include a supercharger compressor bypass configured to selectively recirculate a portion of the compressed output of the supercharger upstream of the supercharger.

Abstract: In an internal combustion engine and a method of operation the internal combustion engine which includes a high pressure and a low pressure turbocharger having exhaust gas turbines arranged in series in an engine exhaust line provided with a high pressure exhaust gas recirculation line and a low pressure exhaust gas recirculation line via which exhaust gas can be conducted to an inlet line of the engine, the arrangement is switchable depending on the engine speed between an exhaust gas recirculation by way of the high pressure line and an exhaust gas recirculation by way of both, the high pressure and the low pressure line, to achieve low emissions and low fuel consumption.

Abstract: A system for recovering, engine exhaust energy is provided. The system includes an exhaust system including a first exhaust branch and a second exhaust branch. The system includes a first and a second group of exhaust valves associated with a plurality of engine cylinders. The system also includes an energy recovering assembly. The system further includes a control mechanism configured to control at least one of the first and second groups of exhaust valves according to a determined timing strategy based on at least one engine operating parameter.

Abstract: A device for utilizing the waste heat of an internal combustion includes a single-stage or multi-stage supercharging device, which is designed as an exhaust-gas turbocharger in particular. The single-stage or multi-stage supercharging device is assigned an additional supercharging device including an expansion machine acted upon by an auxiliary circuit, in particular a steam circuit.

Abstract: A four-cylinder engine has a valve overlap period during which an exhaust valve and an intake valve of each cylinder are both opened. Cylinder pipes for cylinders having adjacent ignition timings of the engine are connected to a turbo charger, and cylinder pipes for cylinders having adjacent ignition timings are connected to another turbo charger. Accordingly, a properly great supercharging pressure can be obtained in a low engine-speed area.

Abstract: In a vehicle, which is provided with: a primary turbo and a secondary turbo, each of which is of an exhaust driven type; an exhaust changeover valve and an intake changeover valve, which are placed in a secondary exhaust passage and a secondary intake passage corresponding to the secondary turbo, respectively; and an intake bypass valve placed in an intake bypass passage, an ECU sets the opening/closing state of each changeover valve to an opening/closing state corresponding to a twin turbo mode at the time of engine stop, and it uses the drive control of each changeover valve which is necessitated in the transition to a single turbo mode at the engine start, thereby performing the sticking detection of the changeover valve at the same time.

Abstract: An engine system is provided. The system comprises an engine, first and second compressors supplying air to the engine, a first compressor recirculation valve adjustable to two restriction levels, and a second compressor recirculation valve adjustable to three or more restriction levels. In this way, the first and second compressor recirculation valves may be controlled to avoid compressor surge while providing a sufficient amount of boost to meet power demands.

Abstract: It is intended to provide: an electric supercharging apparatus wherein, with a simple structure, rotor windage loss in an electric motor for driving a compressor is reduced and good cooling performance is produced; and a multi-stage supercharging system using the electric supercharging device. This electric supercharging apparatus is provided with: a first cooling passage formed in a stator along a motor coil and communicating a gas supply port with a gas discharge port in a motor housing; and a first intake passage connecting the gas discharge port to an intake port of a compressor. This electric supercharging apparatus is configured to introduce outside air into the first cooling passage via the gas supply port by applying negative pressure to the first cooling passage via the first intake passage, thereby cooling the inside of the motor housing.

Abstract: A supercharger compressor includes a plurality of rotors rotatably mounted in a housing, a first inlet for air, a second inlet for recirculated exhaust gas, and a flow separator. The flow separator is arranged interior the housing and configured to form a slideable seal with at least one rotor of the plurality of rotors, the slideable seal fluidically isolating the first inlet from the second inlet, at least in part, and retarding pressure equalization therebetween.

Abstract: Methods and systems are provided for an engine including a first turbocharger having a first compressor and a second turbocharger having a second compressor. An EGR differential between the first compressor and the second compressor may be increased under a condensation condition, and decreased under a surge condition. The EGR differential may also be decreased when a compressor outlet temperature exceeds an outlet temperature threshold.

Abstract: The disclosure provides a turbo-charging apparatus for a vehicle engine, which includes a first and second turbocharger, an inter-turbine passage connecting a discharging port of a first turbocharger turbine with an introducing port of a second turbocharger turbine, a bypass passage connecting an introducing passage of the first turbocharger turbine with the inter-turbine passage, and a control valve for opening and closing the bypass passage. The inter-turbine passage extends substantially straight from the discharging port of the first turbocharger turbine toward the second turbocharger when viewed from a direction parallel to turbine shafts of the first and second turbochargers, which are arranged substantially parallel to each other, so that the inter-turbine passage connects with an outer circumferential part of the second turbocharger turbine so as to extend in a direction tangent to an outer circumference direction of the second turbocharger turbine.

Abstract: In the case where a low-pressure-side supercharging pressure acquired value corresponding to the pressure of inlet gas at the outlet of a low-pressure compressor operated in a twin supercharging mode is less than a target supercharging pressure in a single supercharging mode, changeover from the twin supercharging mode to the single supercharging mode is prohibited. Meanwhile, in the case where the low-pressure-side supercharging pressure acquired value is equal to or greater than the target supercharging pressure, the changeover from the twin supercharging mode to the single supercharging mode is permitted. Alternatively, in the case where a supercharging pressure during operation in the single supercharging mode is less than a target value of the pressure of supply gas at the outlet of the low-pressure compressor in the twin supercharging mode, changeover from the single supercharging mode to the twin supercharging mode is prohibited.

Abstract: The present invention relates to a rotary-style internal combustion power-plant, and an electric machine, comprising a compressor housing, wherein a compressor is housed, a electric machine housing, located adjacent to the compressor housing, wherein an electric machine is housed, a charge air cooler housing, located adjacent to the electric machine housing, a combustion rotor housing located adjacent to the charge air cooler housing, a power take-off housing located adjacent to the combustion rotor housing, a combustion rotor located adjacent to a power take-off housing, an auxiliary pump housing (oil, coolant, and fuel) located adjacent to the combustion rotor; and turbine housing located adjacent to the auxiliary pump housing (oil and coolant), wherein the housings are manufactured as separate entities and are stacked along a singled axis.

Abstract: A combustion chamber of an internal combustion engine has at least a first and a second exhaust port, which are decoupled downstream of the combustion chamber. The first exhaust port is opened before the second exhaust port during an expansion stroke of the piston. The first exhaust port is coupled to a high-pressure turbine and the second exhaust port is coupled to a low-pressure turbine. By directing exhaust gases at higher pressure to the high-pressure turbine and gases at lower pressure to the low-pressure turbine, the overall energy recovery from the exhaust gases is greater than a system with one or more exhaust turbines coupled in series with all of the exhaust ports.

Abstract: An assembly can include a valve seat for an exhaust bypass valve of a serial turbocharger system where the valve seat includes a base portion and a wall portion that extends axially away from the base portion; and a gasket that includes a planar portion that defines a perimeter and a socket disposed interior to the perimeter, where the socket includes a valve seat surface axially recessed from the planar portion and configured to position the seat. In various examples, the valve seat is positioned in the socket of the gasket and fixed to the gasket. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: Turbines and compressors, which constitute superchargers, are disposed in series on an exhaust gas passage and an air intake passage, respectively. The supercharger is equipped with a supercharger rotation sensor, which transmits a detection signal obtained according to the rotation of the compressor to a control device, a bypass passage, which bypasses exhaust gas from the upstream side to the downstream side of the turbine, and a bypass valve, which regulates the flow rate of exhaust gas flowing through the bypass passage. Control device regulates the rotational speed of the compressors in a high-efficiency range by producing a control signal based on the detection signal from the supercharger rotation sensor, and sending the control signal to the bypass valve.

Abstract: A turbocharger control system for a high-pressure turbocharger and a low-pressure turbocharger includes a turbo mode determination module and a transition control module. The turbo mode determination module determines a transition from a dual turbo mode to a single turbo mode. The high-pressure turbocharger is active in the dual turbo mode and idle in the single turbo mode. The transition control module determines a turbine efficiency of the high-pressure turbocharger and controls the high-pressure turbocharger during the transition based on a predetermined maximum turbine efficiency equation.

Abstract: A method of controlling an engine includes manipulating a wastegate to maintain the operation of the turbocharger within an optimum operating range. A combustion air bypass valve is manipulated between an open position and a closed position to create a negative pressure differential across a supercharger. The supercharger is sequentially disposed in-line before the turbocharger. The negative pressure differential is converted into a torque by the supercharger and transmitted from the supercharger back to the engine to increase the operating efficiency of the engine.

Abstract: A twin turbo assembly is provided for an automotive vehicle that includes a first and second air intake for, a first and second turbo charger that includes, but is not limited to a first and second compressor connected to the first air intake, a first and second intake duct connecting the first turbo charger to a combustion engine. A first and second bypass valve is provided to connect the first and second air intake, respectively to the first and second intake duct bypassing the first and second compressor. Overpressure inside the intake ducts can be discharged to a volume between the air filter and the respective compressor. The released pressure prevents or at least reduces the risk that compressed air inside the intake ducts may flow against the first compressor and the second compressor, so that the noise emission associated with this backflow is reduced or even prevented.

Abstract: There are provided first and second water supply passages to supply cooling water from an engine to first and second center housings of first and second turbochargers, and first and second return passages to return the cooling water from the first and second turbochargers to the engine. A cooling-water connection portion of the first water supply is located above the level of a cooling-water connection portion of the second water supply passage. A vapor releasing passage is provided between the second turbocharger and an upper tank provided on the outside of an engine body at a position located above the connection portion of the second return passage of the second turbocharger. Accordingly, the function of vapor releasing from the first and second turbochargers can be improved, thereby increasing the layout flexibility around the engine.

Abstract: A system is provided for boosting the pressure of air delivered to the intake manifold of an engine during a transient event. The system includes an air flow line that is configured to deliver air to an inlet of a low pressure compressor. The system also includes a high pressure compressor. The system further includes a bypass system having at least one bypass valve and a bypass line. The bypass system is configured to allow at least a portion of the air in the air flow line to bypass the low pressure compressor when the bypass valve is in an open position. The bypass valve may be actuated to an open position during transient events so as to increase the speed at which the pressure, and thus air flow mass, of air being supplied to an engine obtained desired levels.

Abstract: A system is provided for controlling an air handling system for an internal combustion engine. A dual-stage turbocharger includes a high-pressure compressor and variable geometry turbine combination fluidly coupled to a low-pressure compressor and variable geometry turbine combination. A control circuit includes a memory having instructions stored therein that are executable by the control circuit to determine a target low-pressure compressor ratio, a target high-pressure compressor ratio, a target high-pressure compressor inlet temperature and a target high-pressure compressor inlet pressure as a function of a target outlet pressure of the high-pressure compressor and a temperature, a pressure and a target flow rate of air entering the air inlet of the low-pressure compressor, and to control the geometries of the low-pressure and high-pressure turbines as a function of the target low-pressure compressor ratio the target high-pressure compressor ratio respectively.

Abstract: Turbocharger supercharged internal combustion engine, of which the exhaust manifold (22) comprises a first outlet (20) constantly supplying a turbine (18) for driving a compressor (12), a second outlet (34) equipped with means of sealing (36) synchronized with the rotation of the engine in order to supply a recycling conduit (46) of exhaust gas and a third outlet connected by a by-pass conduit (58) at the outlet of the turbine (18).

Abstract: An engine (100) provided with a variable series supercharging system (7) composed of a high-pressure supercharger (10) and a low-pressure supercharger (20), a supercharging pressure sensor (63) for detecting the pressure of intake air pressurized by the variable series supercharging system (7), a high-pressure supercharger rotation sensor (61) for detecting the rotational speed of the high-pressure supercharger (10), a variable actuator (14) for adjusting the capacity of the high-pressure supercharger (10), and a control device (60) capable of controlling the variable actuator (14). The control device (60) controls the variable actuator (14) based on detection signals from the supercharging pressure sensor (63) and the high-pressure supercharger rotation sensor (61).

Abstract: A two-stage turbocharged engine system is provided. The two-stage turbocharged engine system includes an internal combustion engine, a high-pressure turbocharger having a high-pressure turbine for rotating a high-pressure compressor through a connecting shaft, and a low-pressure turbocharger having a low-pressure turbine for rotating a low-pressure compressor by a connecting shaft. The two-stage turbocharged engine system also includes a low-pressure intake line for fluidly connecting the outlet of low-pressure compressor to the inlet of high-pressure compressor, a high-pressure intake line for fluidly connecting the outlet of high-pressure compressor to an air cooler, and a bypass device for selectively fluidly connecting a first branching point located in low-pressure intake line to a second branching point located in high-pressure intake line to thereby bypass the high-pressure compressor. The bypass device is located closer to the low-pressure compressor than to the high-pressure compressor.

Abstract: A supercharged internal combustion engine having a plurality of exhaust-driven superchargers staggered as a function of output of the engine, each connected or disconnected with a common exhaust manifold via an exhaust-driven turbine and an exhaust gas valve. Valve mechanisms are provided for changeover of transition air of an auxiliary compressor, having an output side connected to a common combustion air manifold, and of compressor air of a respective supercharger compressor added in staggered operation. Changeover is effected as a function of supercharger speed and combustion air pressure. Each valve mechanism has an ambient air valve, disposed between supercharger compressor outlet and combustion air manifold, and a supply air valve disposed between the compressor outlet and ambient air valve and leading to auxiliary compressor air inlet. A processor having a stored requirements profile activates/deactivates the exhaust gas valves, valve mechanisms and an auxiliary compressor motor.

Abstract: An apparatus for determining an abnormality of a control valve is applied to an internal combustion engine having a first supercharger, a second supercharger, a first control valve, and a second control valve. The apparatus includes an electronic control unit to obtain two supercharging-pressure-corresponding-values before and after an opening degree of the first control valve is changed during a period in which the engine is operated in a specific operating state under which the first supercharger supercharges the engine more efficiently than the second supercharger, and to determine whether or not the second control valve is abnormal based on the two values with respect to the change of the opening degree of the first control valve.

Abstract: Methods and systems are provided for a boosted engine having a split intake system coupled to a split exhaust system. Aircharges of differing composition, pressure, and temperature may be delivered to the engine through the split intake system at different points of an engine cycle. In this way, boost and EGR benefits may be extended.

Abstract: The invention relates to a method for operating an internal combustion engine (1) with two-stage turbocharging by a low-pressure exhaust gas turbine (6) and a high-pressure exhaust gas turbine (7), the low-pressure exhaust gas turbine (6) being positioned downstream of the high-pressure exhaust gas turbine (7) in the exhaust system (3) of the internal combustion engine (1), and the high-pressure exhaust gas turbine (7) being provided with a bypass line (11) with a control valve (12).

Abstract: A turbine housing for a high-pressure turbo-charger of a turbo-charger engine system for an internal combustion engine is provided that includes, but is not limited to a low-pressure charger opening for taking up a low-pressure turbo-charger and a high-pressure charger opening for taking up a high-pressure turbo-charger. A high-pressure exhaust opening is attached to a corresponding flange at an exhaust manifold of the engine and there is a short-cut exhaust opening with a high-pressure turbine by-pass valve area attached to a corresponding flange at the exhaust manifold. An external connection opening is attached to a muffler, a waste gate valve area being provided in the close vicinity of the external connection opening.

Abstract: The present invention relates to a two-stage supercharging system for an internal-combustion engine (10) comprising at least one cylinder (12) with an intake distributor (16) and an exhaust manifold (18), as well as a recirculation line (78) for recycling the exhaust gas to the intake of said engine, said system comprising a high-pressure supercharging stage (22) with a turbocharger including an expansion turbine (26) connected to a compressor (30) and a low-pressure supercharging stage (24) with a turbocharger including an expansion turbine (28) connected to a compressor (32), and exhaust gas purification means arranged between exhaust outlet (40) and turbine (26) of the high-pressure turbocharger. According to the invention, the system comprises an exhaust gas bypass branch (70) going from outlet (40) of the engine exhaust and ending at turbine (28) of low-pressure turbocharger (24).

Abstract: A regulated two-stage turbocharger system is provided. The turbocharger system includes high-pressure and low-pressure turbochargers in communication with one another. The turbocharger system includes a valve system having valves that are independently controllable so as to selectively control the gas flow into the turbine portions of the high-pressure turbocharger and the low-pressure turbocharger. The valves are asymmetric with differing perimeters, diameters, and sizes with respect to one another.

Abstract: An air supply system is provided that uses two sets of rotors on a common set of shafts to boost air in two stages. The air supply system includes a housing and a first and a second rotatable shaft at least partially within the housing. A first and a second pair of rotors are included. Each pair of rotors has a first rotor supported for rotation on the first shaft and a second rotor supported for rotation on the second shaft. The housing has an inlet at the first pair of rotors, an outlet at the second pair of rotors, and an internal chamber between the first and the second pairs of rotors. Air flow from the inlet to the outlet thereby has a first pressure boost from the inlet to the internal chamber and a second pressure boost from the inlet chamber to the outlet.

Abstract: An engine system is provided. The system comprises an engine, first and second compressors supplying air to the engine, a first compressor recirculation valve adjustable to two restriction levels, and a second compressor recirculation valve adjustable to three or more restriction levels. In this way, the first and second compressor recirculation valves may be controlled to avoid compressor surge while providing a sufficient amount of boost to meet power demands.

Abstract: An engine comprises an intake manifold, first and second cylinder banks, a turbocharger, a flow passage, and first and second cylinder banks. The first and second cylinder banks are each in fluid communication with a respective output of the intake manifold. The turbocharger is associated with the second cylinder bank and includes a compressor input port and a compressor output port. The flow passage is in fluid communication with each of the compressor output port and an input of the intake manifold.

Abstract: An internal combustion engine is disclosed, comprising at least one first compression device and at least one second compression device which is connected in series relative to the first compression device. At least one bypass pipe bypasses at least one compression device. At least one controllable valve is arranged in the at least one bypass pipe such that the amount of fluid which can be recirculated around the compression device can be controlled.

Abstract: In a gas guide system, a combustion engine and a method for operating the engine comprising a gas supply arrangement for supplying gas to the engine, a gas discharge system including an exhaust gas treatment unit for releasing gas from the engine, the gas guide system including a first partial gas discharge line for discharging a first partial gas stream from a first fired cylinder group via the exhaust gas treatment unit and a second gas discharge line for discharging a second partial gas stream from a second unfired cylinder group separately from the hot gas stream directed through the exhaust gas treatment unit to keep it at operating temperatures.

Abstract: An engine system for a vehicle is provided, comprising an internal combustion engine including an exhaust system; a first turbine including a first wastegate and arranged along a first branch of the exhaust system, a second turbine including a second wastegate and arranged along a second branch of the exhaust system; a first exhaust gas sensor arranged along the first branch of the exhaust system downstream of the first turbine and first wastegate; a second exhaust gas sensor arranged along the second branch of the exhaust system downstream of the second turbine and the second wastegate; and a control system configured to command the first and second wastegates to a closed or open position and to indicate one of said wastegates as unresponsive to said command in response to a temperature difference between the first and second branches indicated by the first and second exhaust gas sensors.

Abstract: The invention relates to a multistep turbocharger arrangement (1) for an internal combustion engine with a high-pressure step (2), with a low-pressure step (3) which can be brought into operative connection to the high-pressure step (2) over a fluid passage system (4) which can be opened and closed, and with a control unit (5) for controlling the operative connection between the high-pressure step (2) and the low-pressure step (3), wherein the control unit (5) and the fluid passage system (4) are integrated in an engine exhaust manifold (6) which is disposed between the high-pressure step (2) and the low-pressure step (3).