DE102008029197A1 - Device for selective cylinder cutoff in rechargeable combustion engine, has two cylinders which are shiftable and detachable and high pressure stage is provided which consists of compressor and turbine - Google Patents

Abstract

The device (1) has two cylinders (3.1,3.2) which are shiftable and detachable. A high pressure stage is provided which consists of a compressor (4.1) and a turbine (4.2) and a low pressure stage is provided which consists of another compressor (5.1) and a turbine (5.2). The compressor of the low pressure stage is arranged upstream to the compressor of the high pressure stage in a fresh-air duct (6). The turbine of the low pressure stage is arranged downstream to the turbine of the high pressure stage in an exhaust gas line (7). An independent claim is included for a method for selective cylinder cutoff in a rechargeable combustion engine.

Description

Technical area

The The invention relates to an apparatus and a method for selective Cylinder shutdown of a rechargeable internal combustion engine. The internal combustion engine includes at least one high pressure stage and at least one low pressure stage.

State of the art

From the GB 2 430 708 A is an internal combustion engine with selectively off and switchable cylinders known. The internal combustion engine comprises two turbochargers each with a compressor and a turbine. An exhaust system of the internal combustion engine establishes a connection between all cylinders and the two turbines of the exhaust gas turbocharger. By means of valves in the exhaust system, the exhaust gas mass flow can be directed either via one, the other or both turbines. The valves are controlled depending on the number of deactivated cylinders.

One Focus of development work on internal combustion engines aims on the reduction of fuel consumption and pollutant emissions from. Here, the achievable performance and the response be maintained as possible.

A Possible measure here is the turbocharger. Especially since the introduction of the variable turbine geometry The turbocharger could be a suitable means of reduction enforce the fuel consumption of diesel engines.

Also In gasoline engines, the turbocharging is increasingly used. Due to the relatively high exhaust gas temperatures in full load operation can However, the variable turbine geometry only with very high cost be used. Usually, gasoline engines therefore equipped with wastegate turbochargers, but always the compromise found between the response and the achievable performance must become.

One already proven, but also costly process is the Combination of variable timing drive and the layer burning process.

Object of the invention

Of the Invention is the object of providing a device and a method based on the operating characteristics and improve the response of the turbocharger.

Solution of the task

The Task is achieved by a device according to claim 1 and solved by a method according to claim 7.

Advantages of the invention

One Aspect of the invention is in addition to the selective cylinder selection in an arrangement and an operation of the exhaust gas turbochargers to the effect, that in each operating range of the internal combustion engine (partial load, transition Part load at full load, full load and transition from full load in part load) always work in an optimal performance range. In addition to the consideration of the optimal operating ranges the exhaust gas turbocharger is another aspect of the reduction of their response times.

Of the The basic idea is that with a low power requirement only a "small" engine, d. H. at least one Cylinder is switched off and at least one cylinder is switched on, is operated. On the other hand should at higher power requirement then a "big" engine, d. H. at least two cylinders are switched on, can be used. Through this if necessary switching between "two" motors Fuel savings are achievable.

These "two" engines are advantageously each with a to their swallowing behavior equipped exhaust gas turbocharger equipped. The adaptation The exhaust gas turbocharger means in particular one of the engine slipping behavior adapted selection of exhaust gas turbochargers. The criterion for this can be the exhaust gas turbocharger maps of the manufacturer. The leadership / leadership the fresh air mass flow is made such that through the compressor the high-pressure stage only a part of the total number of cylinders and not all cylinders are supplied with compressed by him fresh air. The turbine of the high pressure stage, however, can of all cylinders be exposed to exhaust gas. This different assignment is made especially in the acceleration phase, the a transitional phase of the "small" engine represents the "big" engine, the required boost pressure as soon as possible to be able to provide.

Of the Compressor of the high-pressure stage is used for the "small" engine However, it is also the "big" engine involved, as it is advantageous in the "switching" of the "small" engine to the "big" engine and vice versa is activated.

Depending on the load requirement, the compressor of the high-pressure stage can be partially or completely bypassed. This bypass is advantageously carried out by means of a bypass valve, which in the bypass line is arranged. The bypass valve assumes the two states "open" and "closed".

to Implementation of the method according to the invention it is not necessary that with the bypass valve further states, for example, "partially opened" or "partially closed, as can be seen in a part-load or Acceleration / deceleration operation, the bypass valve is closed is and a part of the cylinder from the compressor of the high-pressure stage compressed fresh air is supplied and optionally the other part of the cylinder from the compressor of the low-pressure stage compressed Fresh air is supplied. In full load operation is the bypass valve open and all cylinders are only from the compressor Low pressure stage fed compressed fresh air.

The Turbine of the high-pressure stage depends on the load requirement completely bypassable. This bypass is advantageously carried out by means of a bypass valve, which is arranged in the bypass line is. The bypass valve assumes the two states "open" and "closed".

to Implementation of the method according to the invention it is not necessary that with the bypass valve further states, for example, "partially opened" or "partially closed ", are present, as in a part-load operation or acceleration / deceleration operation the bypass valve is closed and the exhaust gas mass flow of the switched Cylinders first via the turbine of the high pressure stage and then via the turbine of the low-pressure stage is relaxed. In full load operation, the bypass valve is open and the exhaust mass flow of all cylinders is only about the turbine of the low pressure stage relaxes.

advantageously, the dimensioning of the compressor and the turbine takes place High-pressure stage for full-load operation of those cylinders, which compressed over the compressor of the high-pressure stage Fresh air can be supplied. For example, at one Four cylinder engine two cylinders from the compressor of the high pressure stage compressed fresh air supplied, so are the compressor and the turbine for optimal two-cylinder full-load operation designed.

The Dimensioning of the low-pressure stage is advantageously carried out for a full load operation with all cylinders.

through the device according to the invention and the invention Method, no changes need to be made to the opening and closing times of the valves for the cylinders be made. For the inventive Device and the method according to the invention become the cylinder specific fuel quantities and the guidance the fresh air mass flow and the exhaust gas mass flow accordingly changed according to the respective requirements.

drawings

It demonstrate:

1a : a schematic representation of a device according to the invention in a first part-load operation;

1b a schematic representation of a device according to the invention in a second partial load operation;

1c a schematic representation of a device according to the invention in a third part-load operation;

2 : a schematic representation of the device according to the invention in the transition phase from part-load operation to full-load operation;

3 : a schematic representation of a device according to the invention in full load operation;

4 : A schematic representation of a device according to the invention for a self-igniting internal combustion engine.

The 1a shows a schematic representation of a device according to the invention 1 , A spark ignition internal combustion engine 2 , for example, a gasoline engine, includes four cylinders 3.1 . 3.2 of which two cylinders 3.1 switched on and two cylinders 3.2 are switched off. The shutdown of the cylinder takes place here in the double sense. On the one hand by reducing the output power to values less than zero (towing) and on the other hand by reducing the supplied gas or air quantity to values equal to zero. Execution of shutdown of cylinders 3.2 Here is such that the injection and ignition are disabled and that the air supply by closing the throttle 9 is prevented.

The internal combustion engine 2 is with a high pressure stage 4 consisting of a compressor 4.1 and a turbine 4.2 , and a low pressure stage 5 consisting of a compressor 5.1 and a turbine 5.2 , rechargeable. The compressor 4.1 the high pressure stage 4 is downstream of the compressor 5.1 the low pressure stage 5 in a fresh air line 6 arranged. The turbine 4.2 the high pressure stage 4 is upstream of the turbine 5.2 the low pressure stage 5 in an exhaust pipe 7 arranged.

Downstream of the compressor 4.1 the high pressure stage 4 is a throttle 8th arranged. Downstream of the compressor 5.1 the low pressure stage 5 is a throttle 9 arranged. Downstream of the throttle 9 is a bypass valve 10 arranged.

The compressor 4.1 the high pressure stage 4 and the throttle 8th are by means of a bypass line 11 that the throttle 9 and the bypass valve 10 includes, passable. The bypass line 11 branches downstream of the compressor 5.1 the low pressure stage 5 from the fresh air line 6 and opens again downstream of the bypass valve 10 into the fresh air line 6 one.

The deactivated cylinders 3.2 are fresh air side with the bypass line 11 connected. The connected cylinders 3.1 are fresh air side with the fresh air line 6 connected.

Upstream of the turbine 5.2 the low pressure stage 5 is a bypass valve 12 arranged. The turbine 4.2 the high pressure stage 4 is by means of a bypass line 13 that the bypass valve 12 includes, passable.

The bypass line 13 branches upstream of the turbine 4.2 the high pressure stage 4 from the exhaust pipe 7 and ends upstream of the turbine 5.2 the low pressure stage 5 back into the exhaust pipe 7 one.

The deactivated cylinders 3.2 and the connected cylinders 3.1 are exhaust side with the exhaust pipe 7 connected.

The internal combustion engine 2 can with the two connected cylinders 3.1 operated up to a power, which in this case for all connected cylinders 3.1 half of the maximum achievable performance. Fresh air side are the throttle 9 and the bypass valve 10 (completely) closed.

The regulation of the lower part load takes place by means of the throttle valve 8th , Unless the throttle 8th is fully opened, is a dethrottled operation of the internal combustion engine 2 possible in the lower part load.

Exhaust side is the bypass valve 12 (completely) closed.

The fresh air mass flow flows in the direction of the arrow A and is first from the compressor 5.1 the low pressure stage 5 and then from the compressor 4.1 the high pressure stage 4 compacted. The compressed fresh air mass flow is the two connected cylinders 3.1 fed.

The exhaust gas mass flow of the two connected cylinders 3.1 flows in the direction of arrow B and is first over the turbine 4.2 the high pressure stage 4 and then over the turbine 5.2 the low pressure stage 5 relaxed. The two deactivated cylinders 3.2 no fresh air mass flow is supplied.

The 1b shows the device according to the invention 1 for a partial load operation of the spark-ignition internal combustion engine 2 where two cylinders 3.1 be fully operated (fully switched on). Shutdown of two cylinders 3.1.1 In this case, it covers only the reduction of its power output to zero (idling mode). The adjustment of the load of the cylinders 3.1.1 is based on the throttle 9 , All four cylinders 3.1 . 3.1.1 are operated with a stoichiometric combustion air ratio (λ = 1), so that an exhaust aftertreatment, for example by means of a 3-way catalyst, can be optimally operated.

The fresh air mass flow flows in the direction of the arrow A, is first from the compressor 5.1 the low pressure stage 5 compressed and then flows in the direction of arrow A2 to a small part on the partially opened throttle 9 the bypass 11 to the two cylinders 3.1.1 and in the direction of arrow A1 to a large extent via the compressor 4.1 the high pressure stage 4 , in which the fresh air mass flow is compressed again, and on the almost completely open throttle 8th to the two cylinders 3.1 ,

The total exhaust gas mass flow of the cylinders 3.1 . 3.1.1 flows in the direction of arrow B first to the turbine 4.2 the high pressure stage 4 in which the exhaust gas mass flow is released, and then to the turbine 5.2 the low pressure stage 5 in which the exhaust gas mass flow is relaxed again.

The 1c shows the device according to the invention 1 for a partial load operation of the spark-ignition internal combustion engine 2 where two cylinders 3.1 operated with a stoichiometric combustion air ratio (λ = 1) (fully switched on). Shutdown of two cylinders 3.1.2 In this case, this includes only the deactivation of the injection and the ignition, so that these cylinders 3.1.2 are operated exclusively with air, ie it will be the clocks "suck in air", "compressed air" and "expand compressed air" carried out. The cylinders 3.1.2 amount of air supplied is via the throttle 9 adjustable.

The fresh air mass flow flows in the direction of the arrow A, is first from the compressor 5.1 the low pressure stage 5 compressed and then flows in the direction of arrow A2 to a small part on the partially opened throttle 9 the bypass 11 to the two cylinders 3.1.1 and in the direction of arrow A1 to a large extent via the compressor 4.1 the high pressure stage 4 , in which the fresh air mass flow is compressed again, and on the almost completely open throttle 8th to the two cylinders 3.1 ,

The total exhaust gas mass flow of the cylinders 3.1 and the total ejected fresh air mass flow of the cylinders 3.1.2 flows in the direction of arrow B, first to the turbine 4.2 the high pressure stage 4 and then to the turbine 5.2 the low pressure stage 5 ,

The 2 shows the device according to the invention 1 in the transition phase from part load operation to full load operation of the spark ignition internal combustion engine 2 , In this transitional phase, which accelerates the internal combustion engine 2 Serves are all four cylinders 3.1 switched on, ie all cylinders 3.1 are supplied with air and the injection and the ignition is for all cylinders 3.1 active.

This illustrated device 1 can also be used for the transition phase from full load operation to partial load operation, which allows for the deceleration of the internal combustion engine 2 can be chosen.

The fresh air mass flow is first from the compressor 5.1 the low pressure stage 5 compressed and then flows to a part on the almost completely open throttle 9 the bypass 11 to the two cylinders 3.1 and to a part about the compressor 4.1 the high pressure stage 4 , in which the fresh air mass flow is compressed again, and on the almost completely open throttle 8th to the other two cylinders 3.1 ,

The entire exhaust gas mass flow of all four cylinders 3.1 flows first to the turbine 4.2 the high pressure stage 4 in which the exhaust gas mass flow is released, and then to the turbine 5.2 the low pressure stage 5 in which the exhaust gas mass flow is relaxed again.

For the dimensioning or for the appropriate selection of a charging system, the air requirement of an internal combustion engine 2 Usually represented by its so-called engine intake lines in a compressor map. To generate a required drive power a corresponding amount of fresh air is required. This can also be provided at a given compressor pressure ratio at given engine slugging lines. The compressor 4.1 the high pressure stage 4 is dimensioned so that the engine intake lines both in the partial load, as well as in the full load in the stable operating range of the map of the compressor 4.1 lie. In the calculation of the engine intake required for the design of the high-pressure stage 4 does not work, as usual, the total number of cylinders 3.1 . 3.1.1 . 3.1.2 . 3.2 but it is only the part of the number of cylinders 3.1 one (here two), which from the compressor 4.1 is also supplied only with air. The drive power required for the compressor 4.1 must be applied in a stationary operating point is from the turbine 4.2 provided. The throughput characteristic of the turbine 4.2 is therefore chosen so that at any time sufficient drive power for the compressor 4.1 is available at the given operating point at a present turbocharger speed and at a present sum of fresh air and fuel mass flow.

The 3 shows the device according to the invention 1 for a full load operation of the spark ignition internal combustion engine 2 in which all four cylinders 3.1 are switched on.

The fresh air mass flow is first from the compressor 5.1 the low pressure stage 5 compressed and then flows to a part on the almost completely open throttle 9 the bypass 11 to the two cylinders 3.1 and to a part about the compressor 4.1 the high pressure stage 4 , in which the fresh air mass flow is compressed again, and on the almost completely open throttle 8th to the other two cylinders 3.1 ,

The entire exhaust gas mass flow of all four cylinders 3.1 flows over the bypass line 13 with the fully opened bypass valve 12 to the turbine 5.2 the low pressure stage 5 in which the exhaust gas mass flow is released.

The dimensioning of the low pressure stage 5 is designed for optimal operation in full load with the four cylinders connected 3.1 of the internal combustion engine 2 ,

The 4 shows the device according to the invention 1 for a self-igniting internal combustion engine 2 , for example diesel engine.

The arrangement of the bypass line 11 for partial or complete bypass of the turbine 4.1 the high pressure stage 4 can also be done differently than shown in the figures. It is only essential that a part of the cylinder 3.1 but not all cylinders 3.1 . 3.1.1 . 3.1.2 . 3.2 , over the compressor 4.1 the high pressure stage 4 compressed fresh air can be obtained for the remaining cylinders 3.1.1 . 3.1.2 . 3.2 this feed is not possible.

1

contraption

2

internal combustion engine

3.1

sent off cylinder

3.1.1

sent off cylinder

3.1.2

sent off cylinder

3.2

switched off cylinder

4

High pressure stage

4.1

compressor

4.2

turbine

5

Low pressure stage

5.1

compressor

5.2

turbine

6

Fresh air line

7

exhaust pipe

8th

throttle

9

throttle

10

bypass valve

11

bypass line

12

bypass valve

13

bypass line

A

arrow

A1

arrow

A2

arrow

B

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• GB 2430708 A [0002]

Claims (15)

Contraption ( 1 ) for selective cylinder deactivation of a rechargeable internal combustion engine ( 2 ) with at least two cylinders ( 3.1 . 3.1.1 . 3.1.2 . 3.2 ), which can be activated ( 3.1 . 3.1.1 . 3.1.2 ) and can be switched off ( 3.2 ), and at least one high pressure stage ( 4 ) comprising a compressor ( 4.1 ) and a turbine ( 4.2 ), and at least one low-pressure stage ( 5 ) comprising a compressor ( 5.1 ) and a turbine ( 5.2 ), wherein - in a fresh air line ( 6 ) of the compressor ( 5.1 ) of the low-pressure stage ( 5 ) upstream of the compressor ( 4.1 ) of the high-pressure stage ( 4 ), and - the compressor ( 4.1 ) of the high-pressure stage ( 4 ) partially or completely by means of a bypass ( 11 ) is bypassable, and - in an exhaust pipe ( 7 ) the turbine ( 5.2 ) of the low-pressure stage ( 5 ) downstream of the turbine ( 4.2 ) of the high-pressure stage ( 4 ), and - the turbine ( 4.2 ) of the high pressure step ( 4 ) completely by means of a bypass ( 13 ) is bypassable, and - that of the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow only to a part of the connected cylinders ( 3.1 ), at least one cylinder ( 3.1 ) and maximum total cylinder number ( 3.1 . 3.1.1 . 3.1.2 . 3.2 ) minus one, can be supplied, and - the exhaust gas mass flow of the total number of connected cylinders ( 3.1 . 3.1.1 . 3.1.2 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) is relaxing. Contraption ( 1 ) according to claim 1, characterized in that the bypass ( 11 ) a bypass valve ( 10 ), which occupies either the status "open" or the status "closed". Contraption ( 1 ) according to claim 1, characterized in that the bypass ( 13 ) a bypass valve ( 12 ), which occupies either the status "open" or the status "closed". Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the compressor ( 4.1 ) of the high-pressure stage ( 4 ) for a full-load operation for the cylinders which can be supplied via it with compressed fresh air ( 3.1 ) is dimensioned. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the turbine ( 4.2 ) of the high-pressure stage ( 4 ) for a full load operation over the compressor ( 4.1 ) with compressed fresh air feedable cylinder ( 3.1 ) is dimensioned. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the compressor ( 5.1 ) and the turbine ( 5.2 ) of the low-pressure stage ( 5 ) for a full load operation of the total number of cylinders ( 3.1 . 3.1.1 . 3.1.2 ) are dimensioned. Method for selective cylinder deactivation of a rechargeable internal combustion engine ( 2 ) with at least two cylinders ( 3.1 . 3.1.1 . 3.1.2 ), which can be activated ( 3.1 . 3.1.1 . 3.1.2 ) and can be switched off ( 3.2 ), and at least one high pressure stage ( 4 ) comprising a compressor ( 4.1 ) and a turbine ( 4.2 ), and at least one low-pressure stage ( 5 ) comprising a compressor ( 5.1 ) and a turbine ( 5.2 ), and - the compressor ( 5.1 ) of the low-pressure stage ( 5 ) upstream of the compressor ( 4.1 ) of the high-pressure stage ( 4 ), and - the compressor ( 4.1 ) of the high-pressure stage ( 4 ) partially or completely by means of a bypass ( 11 ) is bypassable, and - the turbine ( 5.2 ) of the low-pressure stage ( 5 ) downstream of the turbine ( 4.2 ) of the high-pressure stage ( 4 ), and - the turbine ( 4.2 ) of the high pressure step ( 4 ) completely by means of a bypass ( 13 ) is bypassable, depending on the load control of the internal combustion engine ( 2 ) - that of the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow only to a part of the connected cylinders ( 3.1 ), - the exhaust gas mass flow of the total number of activated cylinders ( 3.1 . 3.1.1 . 3.1.2 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) is relaxing. A method according to claim 7, characterized in that for an operation of the internal combustion engine ( 2 ) in the lower part load only a part of the cylinder ( 3.1 ), at least one cylinder ( 3.1 ), and this connected cylinder ( 3.1 ) via the compressor ( 5.1 ) of the low-pressure stage ( 5 ) and over the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow is supplied, and the exhaust gas mass flow of these activated cylinders ( 3.1 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) and the turbine ( 5.2 ) of the low-pressure stage ( 5 ) is relaxed. A method according to claim 7, characterized in that for an operation of the internal combustion engine ( 2 ) in the lower part load only a part of the cylinder ( 3.1 ), at least one cylinder ( 3.1 ), this connected cylinder ( 3.1 ) via the compressor ( 5.1 ) of the low-pressure stage ( 5 ) and over the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow is supplied, and another part of the cylinder ( 3.1.1 ), at least one cylinder ( 3.1.1 ), one above the compressor ( 5.1 ) of the low-pressure stage ( 5 ) compacted fresh air masses current via the bypass ( 11 ), and the exhaust gas mass flow of the activated cylinders ( 3.1 . 3.1.1 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) and the turbine ( 5.2 ) of the low-pressure stage ( 5 ) is relaxed. Method according to claim 9, characterized in that the cylinders ( 3.1 . 3.1.1 ) are operated with a stoichiometric combustion air ratio. A method according to claim 7, characterized in that for an operation of the internal combustion engine ( 2 ) in the lower part load only a part of the cylinder ( 3.1 ), at least one cylinder ( 3.1 ), this connected cylinder ( 3.1 ) via the compressor ( 5.1 ) of the low-pressure stage ( 5 ) and over the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow is supplied, and a further part of the cylinder ( 3.1.2 ), at least one cylinder ( 3.1.2 ), one above the compressor ( 5.1 ) of the low-pressure stage ( 5 ) compressed fresh air mass flow via the bypass ( 11 ), and in the cylinders ( 3.1.2 ) no combustion occurs, and the exhaust gas mass flow of the connected cylinder ( 3.1 . 3.1.1 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) and the turbine ( 5.2 ) of the low-pressure stage ( 5 ) is relaxed. Method according to at least one of claims 7 to 11, characterized in that for operation of the internal combustion engine ( 2 ) in a transition phase from the partial load to the full load, as well as from the full load to the partial load, all cylinders ( 3.1 ) and a part of the connected cylinders ( 3.1 ), at least one cylinder ( 3.1 ), one above the compressor ( 5.1 ) of the low-pressure stage ( 5 ) and over the compressor ( 4.1 ) of the high-pressure stage ( 4 ) compressed fresh air mass flow is supplied, and the other part of the connected cylinder ( 3.1 ), at least one cylinder ( 3.1 ), one above the compressor ( 5.1 ) of the low-pressure stage ( 5 ) compressed fresh air mass flow via the bypass ( 11 ), and the exhaust gas mass flow of the cylinders ( 3.1 ) over the turbine ( 4.2 ) of the high-pressure stage ( 4 ) and the turbine ( 5.2 ) of the low-pressure stage ( 5 ) is relaxed. Method according to at least one of claims 7 to 12, characterized in that for operation of the internal combustion engine ( 2 ) in full load all cylinders ( 3.1 ) and all cylinders ( 3.1 ) via the compressor ( 5.1 ) of the low-pressure stage ( 5 ) compressed fresh air mass flow via the bypass ( 11 ), and the exhaust gas mass flow of the cylinders ( 3.1 ) via the bypass ( 13 ) of the turbine ( 5.2 ) of the low-pressure stage ( 5 ) is fed and relaxed in this. Method according to at least one of claims 7 to 13, characterized in that the internal combustion engine ( 2 ) is externally ignited, and the fresh air mass flow in the fresh air line ( 6 ) by means of a downstream of the compressor ( 4.1 ) of the high-pressure stage ( 4 ) arranged throttle valve ( 8th ) can be throttled, and the fresh air mass flow in the bypass line ( 11 ) by means of a downstream of the compressor ( 5.1 ) of the low-pressure stage ( 5 ) arranged throttle valve ( 9 ) can be throttled. Method according to at least one of claims 7 to 13, characterized in that the internal combustion engine ( 2 ) is operated self-igniting.