DE102017210749A1 - Method for operating an internal combustion engine, in particular for a motor vehicle, and internal combustion engine - Google Patents

Abstract

The invention relates to a method for operating an at least one combustion chamber (2), an exhaust tract (9) through which exhaust gas can flow from the combustion chamber (2) and at least one internal combustion engine (1) having an exhaust gas aftertreatment device (10) arranged in the exhaust tract (9) Heating operation (step S2 ') for heating the exhaust aftertreatment device (10), with respect to a heating operation (step S2') beforehand normal operation (step S1 ') at the same torque request to the internal combustion engine (1) whose ignition retarded and adjusted by means of an electric compressor (15) a higher air mass in the combustion chamber (2) is promoted (step S2 ').

Description

The invention relates to a method for operating an internal combustion engine, in particular a motor vehicle, according to the respective preamble of claim 1 and 6 , Furthermore, the invention relates to an internal combustion engine, in particular for a motor vehicle.

The DE 10 2010 003 705 A1 discloses a method for operating an internal combustion engine, in particular for a motor vehicle, in a heating operation. The internal combustion engine comprises at least one combustion chamber formed, for example, as a cylinder, an exhaust tract through which exhaust gas can flow from the combustion chamber, and at least one exhaust gas aftertreatment device arranged in the exhaust tract and through which exhaust gas can flow, by means of which the exhaust gas can be aftertreated. In this case, the exhaust gas aftertreatment device is specifically heated in the heating mode.

Furthermore, the DE 10 2015 015 794 A1 a method for heating at least one disposed in an exhaust system of an internal combustion engine and driven by the internal combustion engine motor vehicle exhaust treatment device, while - combustion processes of fuel in the internal combustion engine omitted - at least the exhaust aftertreatment device flowing air flow is effected, which is heated by at least one electric heating element ,

Moreover, from the DE 102 59 052 B3 a method is known in which in a heating operation of an internal combustion engine, a valve overlap of a combustion chamber associated gas exchange valves is set such that by means of a compressor air is conveyed directly from an intake tract through the combustion chamber into an exhaust tract of the internal combustion engine to selectively heat an exhaust aftertreatment device.

Object of the present invention is to develop a method and an internal combustion engine of the type mentioned in such a way that the exhaust gas aftertreatment device can be heated particularly advantageous.

This object is achieved by a method having the features of claim 1, by a method having the features of claim 6 and by an internal combustion engine with the features of claim 10. Advantageous embodiments of the invention are the subject of the dependent claims.

A first aspect of the invention relates to a method for operating an internal combustion engine, in particular a motor vehicle, in a heating mode for the targeted heating of an exhaust gas aftertreatment device. In this case, the internal combustion engine comprises at least one combustion chamber formed, for example, as a cylinder, an exhaust tract through which exhaust gas can flow from the combustion chamber, and the exhaust gas aftertreatment device, which is arranged in the exhaust tract and can therefore be flowed through by the exhaust gas. The exhaust aftertreatment device is used in particular to post-treat the exhaust gas from the combustion chamber and thus to clean it, for example.

In order to heat the exhaust aftertreatment device particularly advantageous, especially particularly fast and thereby particularly cost-effective and thereby to ensure a particularly advantageous running of the internal combustion engine, it is inventively provided that compared to a heating operation temporally anticipated normal operation of the internal combustion engine at the same torque request to the internal combustion engine whose ignition retarded and promoted by means of an electric compressor, a higher air mass in the combustion chamber.

For example, the torque request means that a user of the internal combustion engine requests a load, and thus a torque, which is to be provided by the internal combustion engine by means of an operating element. For this purpose, the user actuates or operates the operating element. The user is, for example, the driver of the motor vehicle, which is equipped with the internal combustion engine and can be driven by means of the internal combustion engine. The control element is then, for example, a pedal, which is also referred to as an accelerator pedal and is movable by the driver in different positions. The respective position corresponds to a respective torque to be provided by the internal combustion engine. The respective torque is provided for example by the internal combustion engine such that the internal combustion engine provides the requested torque via an output shaft designed, for example, as a crankshaft, and thus delivers it. By means of the provided by the internal combustion engine via the output shaft torque then the motor vehicle can be driven.

To provide the torque, that is to satisfy the torque request, for example, the internal combustion engine of an electrical computing device, which is also referred to as a control unit or engine control unit or engine control, driven accordingly, in particular controlled or regulated. In other words, for example, the internal combustion engine is operated by means of the electronic computing device depending on the operation effected by the user or actuation of the operating element, in particular controlled or regulated, that requested by the user by operating or operating the control element torque of the internal combustion engine, in particular via the output shaft is provided.

In normal operation, for example, a first amount of air is introduced into the combustion chamber, in particular by means of the compressor, wherein the first amount for providing the requested torque, that is, for satisfying the torque request is required. In the heating mode, however, for example, a second quantity of air, which is greater than the first quantity, is introduced into the combustion chamber, so that a higher amount of air is introduced into the combustion chamber in the heating operation compared with normal operation than would actually be required to satisfy the current torque requirement. By virtue of this increased amount of air compared to normal operation in the heating mode, the internal combustion engine would provide a higher torque despite the same torque requirement, that is to say despite the fact that the same torque requirement is placed on the internal combustion engine during normal operation and during heating operation. To prevent this, the ignition timing, in particular the ignition angle, retarded, so that despite the larger amount of air, the internal combustion engine in the heating mode compared to the normal operation provides no higher torque. This means, for example, that the torque is limited by the later ignition. As a result, a particularly high temperature of the exhaust gas, in particular in the exhaust gas tract, can be realized, as a result of which the exhaust gas aftertreatment device can be heated up particularly quickly.

The invention is based in particular on the following knowledge: For internal combustion engines, in particular with direct fuel injection and, for example, gasoline direct injection, such an internal combustion engine being designed, for example, as a gasoline engine, there are in principle two possibilities for setting a particularly high exhaust gas temperature without having to install additional components , A first of the possibilities is a late ignition point in order to specifically set a poor efficiency of the internal combustion engine. Here, for example, the ignited mixture may be stoichiometric or slightly lean. However, the adjustment of the ignition timing late is accompanied by an increasing uneven running or internal combustion engine, so that, for example, in an operation of the internal combustion engine with a homogeneous mixture, the adjustment of the ignition timing is limited to late. At low temperatures of the exhaust aftertreatment device, the emissions can be improved by a slightly lean combustion air ratio or mixture, since the exhaust aftertreatment device reaches the required conversion conditions. An emaciation at cold internal combustion engine is only possible to a limited extent.

The second possibility is to additionally introduce fuel into the combustion chamber after ignition has taken place, in particular to inject it directly in order to effect afterburning, in particular in the exhaust gas tract. Usually, the ignited mixture is very lean, the internal combustion engine is usually operated in a shift operation, and due to a charge stratification, the mixture is still flammable. In such a post-injection, however, the burn-through of the additionally injected fuel mass should be ensured.

Further, a so-called secondary air injection is conceivable, in the context of which by means of an external, that is different from the internal combustion engine and additionally provided pump air into the exhaust system, in particular directly, is blown. For this purpose, at least one or more channels is provided, via which the pump blows air as so-called secondary air into the exhaust system. The secondary air is introduced in particular into an exhaust manifold. By setting a rich combustion chamber mixture, there may be an afterburner in the exhaust tract, which is also referred to as the exhaust line, however, to realize the secondary air injection additional components in the form of said channels and the external pump are required. By means of the method according to the invention, it is now possible to avoid additional components, whereby the weight, the number of parts, the cost and the space requirement of the internal combustion engine or a drive device comprising the internal combustion engine can be kept particularly low. At the same time, the exhaust gas aftertreatment device can be heated particularly quickly in order to be able to ensure a sufficient conversion of gaseous exhaust gas components as quickly as possible. Furthermore, by adjusting the ignition timing to late and increasing the air mass in the Compared to the normal operation is promoted during the heating operation in the combustion chamber by means of the compressor, a particularly high exhaust gas temperature can be realized, at the same time excessive running noise of the internal combustion engine can be avoided.

This is possible, in particular, through the use of the electric compressor, whose compressor wheel is driven for compressing and conveying the air by means of an electric machine. As a result, the compressor or its compressor wheel can be operated at least substantially independently of an available mass flow of the exhaust gas, so that particularly high amounts of air can be conveyed into the combustion chamber, if only a small exhaust gas mass flow is available, by means of which, for example, a turbine of Exhaust gas turbocharger could be driven only insufficiently. Since the air is conveyed into the combustion chamber via the already existing intake tract, which is also called the drive system, by means of the electric compressor, which is also referred to as an electric charger or e-charger, additional components such as channels and external pumps can be avoided. The electric compressor is an already used component, by means of which, for example, during normal operation, the air to be supplied to the combustion chamber is compressed in order to realize a particularly advantageous response can. This allows a particularly rapid heating of the exhaust aftertreatment device can be realized without costly additional technology.

In addition, for example, a noble metal loading of the exhaust aftertreatment device can be kept low, so that their cost can be kept in a very small frame. Due to the rapid heating of the exhaust aftertreatment device, the raw emissions during a heating phase can be kept low. By means of the high air mass, which can be conveyed by means of the electric compressor into the combustion chamber and from this into the exhaust tract, at least afterburning in the exhaust gas tract, in particular in the exhaust gas aftertreatment device, can be effected, whereby the exhaust gas aftertreatment device can be heated particularly quickly. In other words, for example, the air conveyed into the combustion chamber by means of the electric compressor and passing from the combustion chamber into the exhaust gas tract burns with fuel, in particular with unburned fuel, in the exhaust gas tract, in particular in the exhaust gas aftertreatment device, as a result of which it can be heated particularly quickly. Characterized in that both by means of the electric compressor, a particularly high air mass or air quantity is conveyed into the combustion chamber and the firing angle is retarded, can be compared to conventional methods a better engine running during the heating operation can be realized because a better cylinder filling can be displayed.

In an advantageous embodiment of the invention, the heating operation is carried out during a fired operation of the internal combustion engine, whereby undesirable impairments of a driving operation of a vehicle equipped with the internal combustion engine motor vehicle can be avoided.

Another embodiment is characterized in that the internal combustion engine is operated with a stoichiometric combustion air ratio, thereby realizing a particularly high smoothness.

In a further embodiment of the invention, the internal combustion engine is operated in a lean operation, so that the mixture in the combustion chamber is lean. As a result, the exhaust gas aftertreatment device can be heated particularly advantageously.

Finally, it has proven to be particularly advantageous if the internal combustion engine provides the same torque during heating operation as in normal operation. As a result, the exhaust gas aftertreatment device can be heated particularly advantageously, wherein at the same time an excessive impairment of a driving operation can be avoided.

A second aspect of the invention relates to a method for operating an internal combustion engine, in particular for a motor vehicle, in a heating mode for the targeted heating of an exhaust gas aftertreatment device. In this case, the internal combustion engine comprises at least one formed for example as a cylinder combustion chamber, an exhaust gas from the combustion chamber flowed through an air intake intake tract, at least one arranged in the intake compressor and disposed in the exhaust tract and consequently from the exhaust gas from the combustion chamber through-flow exhaust aftertreatment device , In the method, a valve overlap of the combustion chamber associated gas exchange valves of the internal combustion engine is set such that by means of the compressor air directly from the intake via or through the combustion chamber is conveyed through into the exhaust tract. This conveyance of the air directly from the intake tract through the combustion chamber into the exhaust tract is also referred to as overflushing, since in the course of overflushing, the air conveyed by the compressor flows or is conveyed from the intake tract through the combustion chamber into the exhaust gas tract.

A first of the gas exchange valves is designed, for example, as an inlet valve, via which the air can flow from the intake tract into the combustion chamber. A second of the gas exchange valves is designed, for example, as an outlet valve, via which the air can flow from the combustion chamber into the exhaust gas tract. In order to realize the aforementioned flushing of the air, the inlet valve and the gas exchange valve are at least temporarily opened simultaneously, so that the air from the intake tract can flow directly into the exhaust tract via the combustion chamber.

In order to be able to heat the exhaust aftertreatment device particularly advantageously, it is inventively provided that an electric compressor is used as the compressor, the compressor wheel is driven to convey the air by means of an electric machine. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

The electric machine is operated, for example, in a motor operation and thus as an electric motor, by means of which the compressor wheel is driven. The compressor wheel is thus not driven or not only by means of a turbine arranged in the exhaust tract, which is driven by the exhaust gas, but the compressor wheel is, in particular or preferably exclusively, driven by the electric machine. The compressor is also referred to as an electric compressor or e-charger.

By using the electric compressor, which is also referred to as an electrically driven or electrically operable compressor, the air can be conveyed by means of the compressor wheel, at least substantially independently of the exhaust gas or of its mass flow. As a result, particularly high speeds and thus a particularly high amount or mass of the air can be realized if the exhaust gas has only a low mass flow. As a result, the exhaust gas aftertreatment device can be heated particularly quickly. Furthermore, by the described over-purge excess and thus a particularly high amount of air can be passed into the exhaust system, without the need for additional and thus cost, space and weight-intensive components are required. For overflowing only the already existing compressor is used.

It has proven to be particularly advantageous if at least one combustion chamber of the internal combustion engine is operated with a rich mixture, so that excess fuel of the rich mixture burns with oxygen contained in the air conveyed directly into the exhaust tract through the combustion chamber directly from the intake tract, whereby the exhaust aftertreatment device heats up becomes. As a result, for example, in the exhaust gas tract a combustion air ratio ( λ ) from 1 set to realize in the exhaust tract, in particular in the exhaust gas aftertreatment device, for example, a post-combustion. In other words, the over-purged air, in particular its oxygen, and the excess fuel from the at least one, designed for example as a cylinder combustion chamber in the exhaust tract, in particular in the exhaust aftertreatment device, afterburned, whereby the exhaust aftertreatment device is strongly and rapidly heated. Due to the rich mixture in the combustion chamber, a particularly advantageous run, in particular engine operation, of the internal combustion engine can be ensured, so that impairments of a driving operation of a motor vehicle equipped with the internal combustion engine caused by the heating operation can be avoided.

In order to realize a particularly advantageous afterburning in the exhaust tract, in particular in the exhaust aftertreatment device, it is provided in a further embodiment of the invention that is used as the at least one combustion chamber of the at least one combustion chamber different, additionally provided further combustion chamber of the internal combustion engine , The oversprayed air thus comes from the at least one combustion chamber or is introduced into the exhaust tract via the at least one combustion chamber, while, however, the excess fuel with which the oversprayed air in the exhaust tract, in particular in the exhaust aftertreatment device, burns, originates from the further combustion chamber. As a result, a particularly effective and rapid afterburning can be realized.

A further embodiment is characterized in that a catalyst, in particular a three-way catalyst, is heated as the exhaust gas aftertreatment device. As a result, the emissions of the internal combustion engine can be kept particularly low because, for example, a heating phase for heating the catalyst can be kept particularly low.

The invention also includes an internal combustion engine, in particular for a motor vehicle, wherein the internal combustion engine for carrying out a method according to the invention is trained. Advantages and advantageous embodiments of the respective method according to the invention are to be regarded as advantages and advantageous embodiments of the internal combustion engine according to the invention and vice versa.

• 1 ausschnittsweise eine schematische Schnittansicht einer erfindungsgemäßen Verbrennungskraftmaschine;
• 2 ein Flussdiagramm zum Veranschaulichen eines erfindungsgemäßen Verfahrens; und
• 3 ein Flussdiagramm zum Veranschaulichen eines erfindungsgemäßen Verfahrens.

Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawings. Showing:

• 1 a detail of a schematic sectional view of an internal combustion engine according to the invention;
• 2 a flowchart illustrating a method according to the invention; and
• 3 a flowchart illustrating a method according to the invention.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows a detail of a schematic sectional view of a whole with 1 designated internal combustion engine for a motor vehicle, in particular for a motor vehicle such as a passenger car. The internal combustion engine 1 comprises at least one cylinder designed as a combustion chamber 2 in which a piston 3 the trained as a reciprocating engine internal combustion engine 1 is recorded translationally movable. The internal combustion engine 1 Furthermore, it comprises a motor housing designed, for example, as a crankcase, in particular as a cylinder crankcase 4 and a trained example as a crankshaft output shaft 5 which rotatably on the motor housing 4 stored and thus about a rotation axis 6 relative to the motor housing 4 is rotatable. The piston 3 is over a connecting rod 7 articulated with the crankshaft (output shaft 5 ), so that the translational movements of the piston 3 in the combustion chamber 2 in a rotational movement of the output shaft 5 around the axis of rotation 6 being transformed.

The internal combustion engine 1 also has an air intake air intake 8th which is also referred to as intake system, intake tract or intake system. By means of the intake tract 8th becomes the intake tract 8th flowing air to the and in particular into the combustion chamber 2 directed. During a fired operation of the internal combustion engine 1 be the combustion chamber 2 said air and a fuel, in particular a liquid fuel, for operating the internal combustion engine 1 fed. This results in the combustion chamber 2 a fuel-air mixture which is ignited at an ignition time, in particular to a firing angle, and thereby burned. This results in exhaust gas of the internal combustion engine 1 , wherein the exhaust gas in the combustion chamber 2 arises.

The internal combustion engine 1 has an exhaust gas tract through which the exhaust gas can flow 9 on, by means of which the exhaust gas from the combustion chamber 2 is dissipated. The exhaust from the combustion chamber 2 flowable exhaust tract 9 includes at least one exhaust aftertreatment device 10 , which is formed for example as a catalyst. In other words, the exhaust aftertreatment device 10 in the exhaust tract 9 arranged and therefore flowed through by the exhaust gas. By means of the exhaust aftertreatment device 10 the exhaust gas is after-treated, whereupon it is discharged to the environment, for example.

The combustion chamber 2 is at least one inlet channel 11 assigned, via which the air from the intake tract 8th in the combustion chamber 2 can flow. Further, in the combustion chamber 2 at least one outlet channel 12 assigned, in which the exhaust gas from the combustion chamber 2 can flow. The inlet channel 11 is a first gas exchange valve 13 assigned, which is designed as an inlet valve. The outlet channel 12 is a second gas exchange valve 14 assigned in the form of an exhaust valve. The respective gas exchange valve is adjustable between a closed position and at least one open position. In the closed position, the inlet valve blocks the inlet channel 11 , so no air from the inlet duct 11 in the combustion chamber 2 can flow. In the open position, however, the inlet valve gives the inlet channel 11 free, allowing air from the inlet duct 11 in the combustion chamber 2 can flow.

As a result, the exhaust valve closes the exhaust port in the closed position 12 , so no exhaust gas from the combustion chamber 2 in the outlet channel 12 can flow. Further, the exhaust valve outputs the exhaust passage 12 free in the open position, so that the exhaust gas from the combustion chamber 2 in the outlet channel 12 can flow. In the intake tract 8th is a compressor 15 arranged, by means of which the intake tract 8th flowing through and the combustion chamber 2 can be compressed or compressed air to be supplied. This includes the compressor 15 a compressor wheel 16 , by means of which the air can be conveyed and compressed.

2 shows a flowchart, based on which a first method for operating the internal combustion engine 1 is illustrated. At a first step S1 of the method becomes the internal combustion engine 1 operated for example in a normal mode. In the context of normal operation, for example, have the gas exchange valves 13 and 14 no valve overlap or a different, first valve overlap on. As part of the first valve overlap, a first time period is provided, during which, for example, the gas exchange valves 13 and 14 temporarily open at the same time.

At a time at the first step S1 subsequent second step S2 of the method becomes the internal combustion engine 1 operated in a heating operation, which differs from the normal operation and connected to the normal operation in time. Within the scope of the heating operation, which differs from the normal operation, the exhaust gas aftertreatment device becomes 10 heated up. As the exhaust aftertreatment device 10 For example, is designed as a catalyst, the heating operation cat heating mode, catalyst heating or cat heating is called.

During the heating operation or during the heating operation, a valve overlap of the gas exchange valves associated with the combustion chamber 13 and 14 set such that by means of the compressor 15 , in particular by means of the compressor wheel 16 , Air directly from the intake 18 through the combustion chamber 2 through into the exhaust tract 9 is encouraged. In other words, therefore, during the heating operation, at least temporarily, a valve overlap of the gas exchange valves 13 and 14 set such that by means of the compressor 15 , in particular by means of the compressor wheel 16 , Air directly from the intake 8th through the combustion chamber 2 through into the exhaust tract 9 is encouraged. In order to be able to distinguish between the valve overlap set at least temporarily during the heating operation and the initially set valve overlap, the valve overlap optionally set during normal operation is also referred to as the first valve overlap, the valve overlap set during the heating operation also being referred to as the second overlap Valve overlap is called. For example, in the context of the second valve overlap, a longer or larger second time span compared to the first time span is set, during which the gas exchange valves 13 and 14 at least temporarily open at the same time. In particular, the gas exchange valves 13 and 14 during the second valve overlap open simultaneously so long that the means of the compressor 15 conveyed air via the inlet channel 11 and over the open gas exchange valve 13 first in the combustion chamber 2 and then from the combustion chamber 2 over the outlet channel 12 and the open gas exchange valve 14 in the exhaust tract 9 can flow. The air is thus flushed, as the air from the intake tract 8th over the combustion chamber 2 directly into the intake tract 8th is encouraged.

To the exhaust aftertreatment device 10 Particularly advantageous, in particular very fast, to heat up, is called the compressor 15 an electric compressor is used. In other words, the compressor 15 an electric compressor whose compressor wheel 16 for conveying the air by means of an electric machine 17 is driven. By driving the compressor wheel 16 is by means of the compressor wheel 16 the air is flushed in the manner described. As a result, for example by means of the compressor wheel 16 a particularly large amount of air overflowed, that is from the intake 8th over the combustion chamber 2 directly into the exhaust tract 9 be encouraged, especially when the exhaust gas has only a small exhaust gas mass flow. In particular, regardless of the mass flow of the exhaust gas particularly high speeds of the compressor wheel 16 will be realized.

Further, it is at the second step S2 preferably provided that at least one combustion chamber of the internal combustion engine 1 operated with a rich mixture, so that excess fuel of the rich mixture with in the directly from the intake 8th through the combustion chamber 2 through into the exhaust tract 9 funded air burns contained oxygen, causing the exhaust aftertreatment device 10 is heated. In other words, the excess fuel and the scavenged air at least afterburning in the exhaust system 9 , in particular in the exhaust aftertreatment device 10 , which causes the exhaust aftertreatment device 10 can be heated up very quickly.

Preferably, the at least one combustion chamber is one of the combustion chamber 2 different, in addition to the combustion chamber 2 provided additional combustion chamber of the internal combustion engine 1 , wherein the further combustion chamber, for example, formed as a cylinder and is not visible in the figures. Thus, for example, the air which burns with the excess fuel comes from the combustion chamber 2 , wherein the fuel with which the over-purged air burns, comes from the further combustion chamber. In this way, for example, during a period of time, a particularly high number of post-combustion in the exhaust system 9 , in particular in the exhaust aftertreatment device 10 , causing the exhaust aftertreatment device 10 can be heated up very quickly. As a result, for example, one on a cold start of the internal combustion engine 1 following heating phase are kept particularly short, so that a particularly low-emission operation is feasible. In addition, the air in the exhaust tract 9 be rinsed and thus introduced without additional components such as external Pumps and external channels must be used. This allows the number of parts, the cost, the space requirement and the weight of the internal combustion engine 1 be kept in a particularly small frame.

3 shows a further flowchart for illustrating a second method for operating the internal combustion engine 1 , At a first step S1 ' of the second method is the internal combustion engine 1 operated in said normal operation. At a time at the first step S1 ' subsequent second step S2 ' of the second method is the internal combustion engine 1 in said heating mode for the targeted heating of the exhaust gas aftertreatment device 10 operated.

To the exhaust aftertreatment device 10 It is the second step to be able to heat up very quickly by means of the second method S2 ' provided that compared to the heating operation anticipatory normal operation of the internal combustion engine 1 at the same moment request to the internal combustion engine 1 whose ignition timing, at which said fuel-air mixture, for example by means of a spark-ignition device, ignited, retarded and adjusted by means of the electric compressor 15 a higher air mass in the combustion chamber 2 is encouraged. In other words, the fuel-air mixture is ignited during normal operation at a first ignition timing. During the heating operation, however, the fuel-air mixture is ignited at a second ignition point, in particular a second ignition angle, which is later than the first ignition point. In addition, compared to the normal operation in the heating operation by means of the electric compressor 15 a higher or larger air mass in the combustion chamber 2 promoted, but during the normal operation and during the heating operation, the same torque request to the internal combustion engine 1 is provided.

Characterized in that the ignition is later during the heating operation than during normal operation, the internal combustion engine 1 during heating operation via the output shaft 5 the same torque as in normal operation, although during heating compared to normal operation, a larger amount of air or air mass in the combustion chamber 2 is introduced. By this compared to the normal operation higher air mass and by the late ignition, a particularly high temperature of the exhaust gas can be realized, in particular without that in the exhaust system 9 Afterburning occur. At the same time, a particularly advantageous cylinder filling can be realized, so that an advantageous engine operation during the heating operation, which is also referred to as the catalytic converter heating phase, can be realized. In the first method, a particularly advantageous engine operation of the internal combustion engine 1 be ensured that in the at least one combustion chamber, a rich mixture is set. Also in the second method, the exhaust aftertreatment device 10 be heated effectively without additional, weight and cost-intensive additional components.

In the second method, it is conceivable that the internal combustion engine 1 operated with stoichiometric combustion air ratio. Furthermore, it is conceivable that the internal combustion engine 1 is operated in a lean operation, so that, for example, the fuel-air mixture, which during the heating operation in the combustion chamber 2 is formed lean (λ> 1).

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2

combustion chamber

3

piston

4

motor housing

5

output shaft

6

axis of rotation

7

pleuel

8th

intake system

9

exhaust tract

10

exhaust treatment device

11

inlet channel

12

exhaust port

13

Gas exchange valve

14

Gas exchange valve

15

compressor

16

compressor

17

electric machine

S1, S1 '

first step

S2, S2 '

second step

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010003705 A1 [0002]
• DE 102015015794 A1 [0003]
• DE 10259052 B3 [0004]

Claims (10)

Method for operating an at least one combustion chamber (2), an exhaust tract (9) through which exhaust gas can flow from the combustion chamber (2) and at least one internal combustion engine (1) having an exhaust gas after-treatment device (10) arranged in the exhaust tract (9) in a heating operation (step S2 ') for heating the exhaust gas aftertreatment device (10), characterized in that with respect to a heating operation (step S2') beforehand normal operation (step S1 ') with the same torque request to the internal combustion engine (1) retarded its ignition and by means of an electric compressor ( 15) a higher air mass in the combustion chamber (2) is promoted (step S2 '). Method according to Claim 1 characterized in that the heating operation (step S2 ') is performed during a fired operation of the internal combustion engine (1). Method according to Claim 2 , characterized in that the internal combustion engine (1) in the heating operation (step S2 ') is operated with a stoichiometric combustion air ratio. Method according to Claim 2 , characterized in that the internal combustion engine (1) in the heating operation (step S2 ') is operated in a lean operation. Method according to one of the preceding claims, characterized in that the internal combustion engine (1) in the heating operation (step S2 ') provides the same torque as in the normal operation (step S1'). Method for operating an at least one combustion chamber (2), an exhaust tract (9) through which exhaust gas can flow from the combustion chamber (2), an intake tract (8) through which air can pass, at least one compressor (15) arranged in the intake tract (8), and at least an internal combustion engine (1) having an exhaust aftertreatment device (10) arranged in the exhaust tract (9) in a heating operation (step S2) for heating the exhaust aftertreatment device (10) in which a valve overlap of the combustion chamber (2) associated gas exchange valves (13, 14) is adjusted, that by means of the compressor (15) air directly from the intake duct (8) through the combustion chamber (2) through the exhaust tract (9) is conveyed (step S2), characterized in that as the compressor (15) an electric Compressor (15) is used, the compressor wheel (16) for conveying the air by means of an electric machine (17) is driven. Method according to Claim 6 , characterized in that at least one combustion chamber of the internal combustion engine (1) is operated with a rich mixture, so that excess fuel of the rich mixture with in the directly from the intake duct (8) through the combustion chamber (2) through the exhaust tract (9) promoted air contained oxygen burns, whereby the exhaust gas aftertreatment device (10) is heated. Method according to Claim 7 , characterized in that as the at least one combustion chamber one of the at least one combustion chamber (2) different, additionally provided further combustion chamber of the internal combustion engine (1) is used. Method according to one of the preceding claims, characterized in that as the exhaust gas aftertreatment device (10), a catalyst is heated. Internal combustion engine (1), in particular for a motor vehicle, wherein the internal combustion engine is designed to carry out a method according to one of the preceding claims.

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