Provided is an engine which is provided with an EGR device, wherein: an actual intake/exhaust gas pressure ratio π1 of an intake-gas pressure P1 to an exhaust-gas pressure P2 is calculated from the detected exhaust-gas pressure P2 and the detected intake-gas pressure P1; an estimated intake/exhaust gas pressure ratio π2 of the intake-gas pressure P1 to the exhaust-gas pressure P2 is calculated from an engine rotational frequency N, and a fuel injection amount F; and, in cases when the actual intake/exhaust gas pressure ratio π1 is less than a prescribed value π0, an EGR gas weight Megr is calculated based on the actual intake/exhaust gas pressure ratio π1, and in cases when the actual intake/exhaust gas pressure ratio π1 is equal to or more than the prescribed value π0, the EGR gas weight Megr is calculated based on the estimated intake/exhaust gas pressure ratio π2.

An annular disk comprises a front surface, a rear surface, an outer surface, and an inner surface. The front surface has a front opening within a front plane. The rear surface has a rear opening within a rear plane. The rear opening, which has a diameter that is smaller than a diameter of the front opening, communicates with the front opening to define a bore for guiding an exhaust stream flowing from a turbocharger to an exhaust outlet. The outer surface connects the front surface to the rear surface and includes an outer angled portion, an outer radial portion, and an outer axial portion. The inner surface includes an inner angled portion, an inner axial portion, and an inner radial portion extending between the inner angled portion and the inner axial portion. The inner radial portion is configured to obstruct a portion of the exhaust stream to increase back pressure.

A method for controlling and/or regulating an exhaust gas turbocharger of an internal combustion engine, the exhaust gas turbocharger being protected against an exceeding of a maximum rotational speed, an actual boost pressure being compared with a setpoint boost pressure. The risk of a maximum rotational speed of the exhaust gas turbocharger being exceeded is prevented in that a manipulated variable assigned to the exhaust gas turbocharger is compared with a manipulated variable limit characteristic and is limited, if necessary, the manipulated variable limit characteristic having a time-limited, first portion and a chronologically subsequent, second portion following a change in the setpoint boost pressure, the first portion ending after a predetermined target time, the second portion of the manipulated variable limit characteristic being reduced with respect to the first portion in such a way that the maximum rotational speed of the exhaust gas turbocharger is not reached.

The invention relates to a method for operating an internal combustion engine (100) having an exhaust-gas turbocharger (5, 10, 15) for compressing the air fed to the internal combustion engine (100), wherein a drive power of a turbine (10) of the exhaust-gas turbocharger (5, 10, 15) in an exhaust tract (20) of the internal combustion engine (100) is changed through variation of a turbine geometry of the turbine (10), wherein, in a first control algorithm (I), a setpoint charge pressure (pL.sub.Soll) at the outlet of the compressor (5) of the exhaust-gas turbocharger (5, 10, 15) in the air feed tract (50) upstream of the combustion motor (55) is controlled in a manner dependent on a setpoint exhaust-gas back pressure (pT1.sub.Soll) to be set in an exhaust tract (20) downstream of the combustion motor (55) upstream of the turbine (10) of the internal combustion engine (100), wherein the setpoint charge pressure (pL.sub.Soll) is assigned an opening cross-sectional area of the turbine (10), which is controlled, by means of an actuating stroke of an actuating element (25) assigned to the turbine (10), in a manner dependent on a setpoint value (25.sub.Soll) assigned to the predefined setpoint charge pressure (pL.sub.Soll). According to the invention, provision is made for the actuating element (25), which is actuated by means of the first control algorithm (I), of the turbine (10) to be controlled by means of a second control algorithm (II), with predefinition of an upper threshold value of the setpoint exhaust-gas back pressure (pT.sub.1Soll) in the exhaust tract (20) upstream of the turbine (10) by intervention into the first control algorithm (I) with an adapted setpoint value (25′.sub.Soll), if, in a primary control path a) of the second control algorithm (II), a control deviation (ΔpT) upstream of the turbine (10) arises which is formed from an actual exhaust-gas back pressure (pT.sub.1lst) upstream of the turbine (10) and the predefined setpoint exhaust-gas back pressure (pT.sub.1Soll) upstream of the turbine (10), and, in a secondary control path b) of the second control algorithm (II), a control deviation (ΔpL) downstream of the compressor (5) arises which is formed from an actual charge pressure (pL.sub.lst) of the compressor (5) and the setpoint charge pressure (pL.sub.Soll) at the outlet of the compressor (5).

An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

A turbocharger control method and related systems are provided. An operational command to control a level of boost provided by the turbocharger is received. In response to receiving the operational command, an exhaust gas recirculation (EGR) valve is instructed to move from a current position to a desired position. A time taken for the EGR valve to move from the current position to the desired position is determined. A maximum rise rate of exhaust manifold pressure corresponding to a predicted EGR valve position is determined. A permitted exhaust manifold pressure limit for the turbocharger is determined based on a current exhaust manifold pressure, the maximum rise rate of exhaust manifold pressure and the time taken. An operation of the turbocharger is controlled such that the permitted exhaust manifold pressure limit is not exceeded.

A turbocharger control valve having an extended feedback cap for altering the performance of a variable geometry turbocharger delivering boost pressure to an engine, the extended feedback cap has an increased cap length which displaces a spool within the turbocharger control valve to alter hydraulic fluid flow through the turbocharger control valve, causing the turbocharger to delay opening a variable inlet to release exhaust pressure, also causing the turbocharger to preemptively close the variable inlet to mitigate loss of exhaust back pressure and boost pressure without a command from a turbocharger control module.

Embodiments are directed to boosting aircraft engine performance for takeoff and critical mission segments by reducing airflow used for cooling exhaust gases. The airflow is reduced by stopping an accessory blower or by closing an external air vent Eliminating the cooling airflow to the exhaust has the effect of lowering the backpressure on the engine, which thereby increases maximum engine power.

Methods and systems for operating an engine with an electrically heated catalyst and an electrically driven compressor are described. In one example, the electrically driven compressor and the electrically heated catalyst are activated before an engine start so that vehicle emissions may be reduced more efficiently at engine starting and thereafter.

A system and method of operating the same includes an engine speed sensor determining an engine speed, an exhaust gas bypass valve, an exhaust gas bypass valve actuator coupled to the exhaust gas bypass valve and a controller. The controller partially opens the exhaust gas bypass valve with a first predetermined effective area greater than fully closed when the engine speed is at idle. The controller determines an acceleration event, holding the exhaust gas bypass valve open at least a second predetermined effective area greater than fully closed in response to the acceleration event.