DE102006057204A1 - Internal-combustion engine has crank case in which crankshaft is supported swiveling, and piston is movable in cylinder and covered by cylinder head forming work space - Google Patents

Abstract

The internal-combustion engine (2) has a crank case in which a crankshaft is supported swiveling. The piston is movable in a cylinder and covered by a cylinder head forming a work space (1a).The combustion air and fuel or their mixture is supplied to work space and exhaust gas is removed into an exhaust gas system. A positioning device is a flap (9) that is displaced between two end positions by an actuator into arbitrary positions. An independent claim is also included for a method of operating an internal combustion engine.

Description

The The invention relates to an internal combustion engine with a crankcase, in a crankshaft is rotatably mounted on the at least one a piston bearing connecting rod is articulated, wherein the piston in one covered by a cylinder head to form a working space Cylinder is movable, wherein the working space combustion air and fuel or a mixture thereof can be fed and exhaust gas is discharged into an exhaust line, and wherein in the Exhaust line a first exhaust gas turbocharger and at least a second via a Control device in the exhaust system switchable exhaust gas turbocharger is arranged and a method for operating such Internal combustion engine.

Such an internal combustion engine with two exhaust gas turbochargers is from the DE 10 2004 061 023 A1 known. In this case, the turbine of the first exhaust gas turbocharger is constantly acted upon by the exhaust gas of the internal combustion engine, while in the supply line to the turbine of the second exhaust gas turbocharger a shut-off valve is turned on. This shut-off valve can be operated in unspecified manner.

Of the Invention is based on the object in an internal combustion engine with at least two exhaust gas turbochargers, in which the second exhaust gas turbocharger switched on according to demand can be, the response of the second exhaust gas turbocharger to improve.

These Task is solved by that the setting means one of a fast actuator in any Positions between two end positions movable flap is, where according to the debt collection process the control of the actuator takes place such that the supercharger speed of the second exhaust gas turbocharger to a value close to the max. Supercharger speed is set. This configuration becomes the instationary behavior the thus equipped internal combustion engine significantly improved. The turbine of the second exhaust gas turbocharger is fed so much exhaust, that this near the max. Charger speed is operated. It will the operating point adjusted by the fact that the compressor side of the second exhaust gas turbocharger is shut off on the suction side. Conceivable it is also necessary to provide the shut-off on the pressure side or the suction side with the print side over Short circuit a bypass line.

In Further development of the invention is actuated by the actuator flap arranged behind the turbine of the exhaust gas turbocharger. This embodiment is preferred because then the turbine is always under exhaust back pressure and this has a positive effect on the control behavior. Basically but it is also possible to turn on the flap in front of the turbine into the exhaust line.

Of the The actuator is preferably an electric actuator, in particular a throttle actuator. Such controllers are available and are characterized by high adjustment speeds. It is thus possible very fast, for example on load change, for example on a driven by the internal combustion engine generator to react and the load point corresponding adjustment of the internal combustion engine make.

In Another embodiment of the invention, the electric actuator with a device which outputs a feedback signal. This feedback signal gives the instantaneous position of the electric actuator again and it can thus an even faster approach to a certain position, the For example, an operating point corresponds to be made.

Of the Controller is preferably characteristic or map-controlled, wherein the characteristic curves or the characteristic field by stationary measurements, for example on a test bench internal combustion engine, can be determined. Then leave the end positions of the flap depending on the load Derive such a map or a characteristic and load switching can the required adjustment of the flap without an overshoot be made. The same advantages arise with a load shutdown.

The the controller controlling the actuator may be preferred to be extended by this feature engine control unit, being this controller a speed signal of the compressor and optionally the feedback signal supplied to the electric actuator. Are more than two exhaust gas turbochargers installed on an internal combustion engine, can also the other exhaust gas turbocharger with the device according to the invention be equipped and operated according to the invention.

Further advantageous embodiments of the invention are the drawing description can be seen in the one embodiment shown in FIG described in more detail is.

The single FIGURE shows in a schematic representation of the subject matter of the present invention. The workroom 1a a cylinder of an internal combustion engine 2 is via a supply line 3 Combustion air or a mixture of combustion air and fuel can be supplied. The burned mixture is as exhaust gas via an exhaust pipe 4 dissipatable as part of an exhaust line. The exhaust pipe 4 flows into the turbine 5 a first exhaust gas turbocharger 6 , The turbine 5 is about a shaft with a compressor 7 connected to the environment a filter device sucks air and this as compressed combustion air optionally via a gas mixer 8th the supply line 3 supplies. The gas mixer 8th is provided when the internal combustion engine is a gas engine and the combustion air for generating an ignitable mixture, a gas, such as landfill gas, is admixed. In the supply line 3 can be in front of or behind the gas mixer 8th furthermore a charge air cooler / mixture cooler 13 to be on. The gas mixer 8th By the way, before the compressor 7 be arranged in the suction line (behind the filter device). From the exhaust pipe 4 branches an exhaust pipe 4a off to the turbine 5a a second exhaust gas turbocharger 6a leads. The second turbocharger 6a also has a compressor 7a on top of the charge air line of the first compressor 7 is interconnected. Output side of the turbine 5a the second exhaust gas turbocharger 6a is designed as an exhaust flap flap 9 in the turbine exhaust line 10 switched on, with the flap 9 from a throttle valve actuator 11 can be moved in any position between two end positions. The compressor 7a is on the suction side and pressure side with shut-off valves 12a . 12b provided, if necessary, with a bypass line 12c be fluidly connected to each other. A controller is connected to sensors that provide the controller with a feedback signal from the throttle actuator 11 and the shut-off valves 12a . 12b and a speed signal of the compressor 7a respectively. Conversely, control lines go to the throttle valve actuator from the control unit 11 and the shut-off valves 12a . 12b from.

The control unit is programmed so that in a load case in which the first turbocharger 6 alone for the compression of combustion air is in operation, the flap 9 from the throttle valve actuator 11 opened so far that the turbine 5a approximately at a speed close to the maximum supercharger speed.

Here is the compressor 7a shut off from the continuing charge air line or the suction side and the pressure side are additionally via a bypass line 12c connected together. This is the exhaust gas turbocharger 6a in idle mode and it is only a small amount of exhaust gas required to achieve the necessary supercharger speed. Incidentally, this value is 70 to 90% of the maximum supercharger speed. If, however, more power is required by the internal combustion engine as a result of a load request, for example of a generator connected to the internal combustion engine, the throttle valve actuator can demand this 11 the flap 9 be opened very quickly and at the same time the shut-off valves 12a . 12b be switched so that the sucked air is supplied to the charge air line. Because of the compressor 7a is operated at a speed value near the maximum supercharger speed, the overall device has a very fast load response response. The power requirement when not in use is very low.

1a

working space

2

Internal combustion engine

3

supply line

4, 4a

exhaust pipe

5, 5a

turbine

6 6a

turbocharger

7, 7a

compressor

8th

gas mixer

9

flap

10

Turbine exhaust duct

11

throttle

12a, 12b

shut-off valve

12c

bypass line

13

Intercooler / mixture cooler

Claims (7)

Internal combustion engine with a crankcase, in which a crankshaft is rotatably mounted on which at least one connecting rod bearing a piston is articulated, wherein the piston is movable in a covered by a cylinder head to form a working chamber cylinder, wherein the working space combustion air and fuel or a mixture can be supplied and exhaust gas is discharged into an exhaust line, and wherein in the exhaust line, a first exhaust gas turbocharger and at least a second via an adjusting device in the exhaust line switchable exhaust gas turbocharger is arranged, characterized in that the adjusting means one of a fast actuator in any position between two end positions movable flap ( 9 ). Internal combustion engine according to claim 1, characterized in that the flap ( 9 ) is arranged behind the turbine of the exhaust gas turbocharger. Internal combustion engine according to claim 1 or 2, characterized characterized in that the actuator is an electric actuator. Internal combustion engine according to claim 3, characterized in that the electric actuator is a throttle valve actuator ( 11 ). Internal combustion engine according to claim 3 or 4, characterized characterized in that the electric actuator with a feedback signal can be acted upon. Method for operating an internal combustion engine with a crankcase, in which a crankshaft is rotatably mounted, on which at least one connecting rod carrying a piston is articulated, wherein the Kol ben in one of a cylinder head to form a working space covered cylinder is movable, wherein the working space combustion air and fuel or a mixture thereof supplied and exhaust gas can be discharged into an exhaust line, wherein in the exhaust line a first exhaust gas turbocharger and at least a second via an adjusting device in the Exhaust gas train switchable exhaust gas turbocharger are operated, characterized in that an adjusting device forming flap ( 9 ) from a fast actuator, in particular a throttle actuator ( 11 ), in any position between two end positions is movable, and that the control of the actuator takes place such that the supercharger speed of the second exhaust gas turbocharger ( 6a ) is set to a value near the maximum supercharger speed. A method according to claim 6, characterized in that a controller controlling the controller, the a speed signal of the compressor ( 7a ) is supplied.