DE102008032604A1 - Exhaust gas flow condition adjusting method for e.g. diesel engine of motor vehicle for desulfurization of catalysts, involves increasing or adjusting pressure gradient from diverging area to junction area - Google Patents

Abstract

The method involves diverging a secondary air mass flow (55) at a diverging area (51) of a fresh air line (45) downstream to a compressed air source in a burner (57) to supply the burner with combustion air. A pressure gradient is increased or adjusted from the diverging area to a junction area by throttling an air mass flow by a throttle, where the throttle is connected downstream to the source and the former area. A partial flow of an exhaust gas flow (3) in the burner is supplied by diverging the partial flow from a turbine (15) of a turbocharger (19) in an exhaust gas auxiliary power line. An independent claim is also included for a device for adjusting a condition of an exhaust gas flow guided in a power train of an internal combustion engine of a motor vehicle.

Description

The The invention relates to a method and a device for adjusting a state of exhaust gas flow of an internal combustion engine of a motor vehicle, with a compressed air source for generating an air mass flow to Supplying the internal combustion engine with combustion air, by means of a opening at a junction in the exhaust stream Burner.

Methods and apparatus for adjusting a state of exhaust gas flow are known. They can be used, for example, for regeneration of a particle filter connected in the exhaust gas flow and / or for desulfurization of catalysts. By means of the burner, a temperature of the exhaust gas flow can be raised. The DE 10 2004 022 186 describes a method for supplying clean compressed air to a diesel oxidation catalyst. Here, compressed air is introduced before a diesel oxidation catalyst. A tap of the introduced before the diesel oxidation catalyst fresh air is carried out by a turbocharger. The DE 44 43 133 A1 relates to an exhaust aftertreatment system of a boost pressure driven internal combustion engine with particulate filter and upstream burner. For thermal regeneration of the particulate filter, the burner is supplied by the compressor of the internal combustion engine with combustion air, which is needed for a regeneration operation of the particulate or soot filter.

From the DE 38 37 472 A1 is known a particulate filter system, wherein a regeneration of a particulate filter by burning the particulate charge in the full flow of the exhaust gas takes place. Fuel and oxygen containing gas is supplied to a burner associated with the particulate filter, wherein the ratio of the fuel supplied to the burner to the oxygen-containing gas at the operating point of the diesel engine at which the power requirement of the burner to reach the regeneration temperature is lowest is approximately stoichiometric and all others Operating points of the diesel engine is substoichiometric. The burner consists of a Luftdrallzerstäuberdüse, a primary combustion chamber and a secondary combustion chamber. The primary combustion chamber has an axial outlet opening. The secondary combustion chamber is cylindrical, like the primary combustion chamber. The primary combustion chamber adjoins the particle filter, wherein a circular baffle plate is provided between the outlet opening of the primary combustion chamber and the particle filter. The opening of the primary combustion chamber before mounted baffle plate is intended to prevent unburned when the primary combs unburned fuel reaches the particulate filter and this endangered by overheating.

From the DE 10 2006 009 943 A1 is an exhaust aftertreatment system with in the direction of flow of exhaust gas of an internal combustion engine arranged in succession, exhaust gas flowed first oxidation catalytic converter, a NOx catalyst device for denitrification of the exhaust gas, means for actively raising an exhaust gas temperature with at least a second oxidation catalyst device, and a device known for particle removal. In this case, a respective operating temperature of the NOx catalyst device and the device for particle removal is adjustable as a function of an exhaust gas temperature and an output of the internal combustion engine. In order to generate a heat tone for the temperature control, a corresponding unit is provided upstream of one or more of the catalyst devices.

task The invention is an improved setting of a state an exhaust gas stream of an internal combustion engine of a motor vehicle to enable.

The Task is with the features of the independent claims solved.

The Method has a branching of a secondary air mass flow at a branch point downstream of the compressed air source in the burner to supply the burner with combustion air and a Raising or setting a pressure gradient from the branch point towards the point of confluence.

Under State in this text are any characteristic of the exhaust stream Understood parameters, such as a temperature, a composition and / or an exhaust lambda value.

ever after the operating condition of the internal combustion engine would become a too low pressure gradient for the operation of the burner between the branch point and the junction. Advantageously, by raising or adjusting the pressure gradient Nevertheless, a secure operation of the burner, so a secured Supply the burner with combustion air. Especially can the burner despite a low load operation, a push operation and / or low-speed operation of the internal combustion engine safely supplied with combustion air. Advantageously, an otherwise necessary for these operating conditions burner fan omitted. The pressure gradient can be increased as long As necessary for the operation of the burner, for example for a regeneration cycle of a switched into the exhaust stream Exhaust gas purification device. It is possible for this time an operation of the internal combustion engine with reduced Efficiency to accept.

at an embodiment of the method are lifting the Pressure gradient by throttling the air mass flow and / or a raising of the pressure gradient by means of one of the compressed air source and the branch point downstream first throttle body provided. Advantageously, by means of the first throttle body to the internal combustion engine throttled partial flow of the air mass flow are throttled, so that the pressure of the branched secondary air mass flow in comparison to the part of the engine passed to the partial flow elevated. Assuming a constant exhaust back pressure This can advantageously increase the pressure gradient become.

at a further preferred embodiment of the method are a raising of the pressure gradient by throttling the Exhaust gas flow and / or raising the pressure gradient by throttling the exhaust stream upstream by means of one of the junction provided second throttle body. Advantageously, the second throttle body be switched into the exhaust stream and upstream of the Increase exhaust backpressure of the internal combustion engine. Advantageous this causes downstream of reducing the pressure the exhaust stream and thus also at the confluence a reduced pressure, which ultimately causes an increase the pressure gradient causes the burner to operate safely.

at a further preferred embodiment of the method are a lifting of the pressure gradient by driving a variable turbine geometry (VTG) of a turbine of an exhaust gas turbocharger the compressed air source and / or raising the pressure gradient by controlling a variable compressor geometry (VCG) of a Compressor of the compressed air source provided. Can be advantageous by means of the variable geometries a differential pressure difference the turbine or a boost pressure increase set become. This can advantageously be done so that the pressure gradient for a safe operation of the burner is raised.

at a further preferred embodiment of the method is a lifting of the pressure drop of the exhaust gas turbocharger by reducing an exhaust gas recirculation rate provided a high pressure exhaust gas recirculation. Advantageous can by reducing the exhaust gas recirculation rate an exhaust back pressure upstream of the turbine of the exhaust gas turbocharger be increased, which advantageously a larger Turbine performance is achievable, the compressor of the exhaust gas turbocharger is available. Advantageously, thereby the compressor a higher boost pressure and thus a higher Provide secondary air mass flow pressure, which ultimately causes an increase in the pressure gradient.

at a further preferred embodiment of the method is a supply of a partial flow of the exhaust gas stream in the Burner by means of branching the partial flow in front of a turbine of the exhaust gas turbocharger intended. Advantageously, thereby a higher temperature the combustion air available to the burner be effected.

at a further preferred embodiment of the method is a lifting of the pressure gradient by lifting a Speed of a mechanical supercharger of the compressed air source provided. By raising the speed or an associated provided increased compression capacity of the supercharger the compressed air source can the boost pressure and thus the pressure gradient be raised.

at a further preferred embodiment of the method is a lifting of the pressure gradient by means of at least one provided the following engine measures of the internal combustion engine. Increasing an idling speed of the internal combustion engine and / or Increasing a temperature of the exhaust stream upstream of the turbine the exhaust gas turbocharger and / or increase the temperature by means of a Post-injection and / or premature opening of exhaust valves of the internal combustion engine. Advantageously effected increasing the temperature of the exhaust stream is higher on the turbine of the exhaust gas turbocharger convertible enthalpy and thus an increase in boost pressure.

The The object is also a method of adjustment a state of an exhaust gas flow of an internal combustion engine of a Motor vehicle, with a compressed air source for generating an air mass flow for supplying the internal combustion engine with combustion air, by means of a burner opening into the exhaust gas flow at a point of confluence, with a branching of a secondary air mass flow at one Branch point downstream of the compressed air source and downstream one of the compressed air source downstream charge air cooler into the burner to supply the burner with combustion air solved. Advantageously, the means of the charge air cooler cooled air mass flow to a higher density, so that advantageously by means of the burner, a higher performance is achievable. In addition, advantageous necessary Lines for guiding the secondary air mass flow be designed smaller.

The object is further provided with a device for setting a state of an exhaust gas flow of an internal combustion engine of a motor vehicle, with a burner opening into the exhaust gas flow at a junction and a compressed-air source for generating an air mass flow for supplying the internal combustion engine and the burner with combustion air, the apparatus being set up, designed and / or constructed for carrying out a method as described above. This results in the advantages described above.

The inventive method and apparatus are particularly advantageous to use in an internal combustion engine with at least one arranged in the exhaust line temporarily regenerated Exhaust gas purification device and at least one upstream of the exhaust gas purification device arranged burner, the fuel at least temporarily with a substoichiometric combustion air ratio (λ) is supplied. During operation of the burner with a stoichiometric combustion air ratio λ a portion of the amount of fuel supplied to the burner in a first reacted at least the burner reaction zone, so burnt and a second part of said fuel reacted in a second reaction zone downstream of the first reaction zone. The distribution of fuel turnover in the reaction zones is specifically, for example by adjusting the combustion air ratio λ in Burner, set or controlled.

in the Main exhaust stream then takes place the further implementation of partially combusted Fuel with oxygen there. For this is an oxygen-rich, d. H. lean exhaust particularly advantageous.

Preferably will not exceed 90% in a given time interval, 80%, 70%, 60%, 50%, 40%, 30% of the burner fed Fuel burned in the first reaction zone burner. Preferably the time interval has a length in the range of 10 sec to 300 sec.

By the stoichiometric operation of the burner can the heating energy introduced into the exhaust mainstream is controlled. there can also be used for high heat input into the exhaust gas a burner of small size can be used because in the burner no complete thermal fuel sales must be done but the full turnover of the fuel specifically downstream in the exhaust system or in one of the exhaust gas purification devices he follows. The due to the substoichiometric operation partially oxidized fuel fractions are very reactive and can in Exhaust main flow even under unfavorable boundary conditions, such as B. low temperature, high space velocity of the exhaust gas, be implemented.

Further Advantages, features and details emerge from the following Description, in reference to the drawing, an embodiment is described in detail. Same, similar and / or functionally identical parts are provided with the same reference numerals. Show it:

1 a schematic view of an apparatus for adjusting a state of an exhaust gas flow of an internal combustion engine of a motor vehicle; and

2 a schematic view of another device for adjusting a state of an exhaust gas flow of an internal combustion engine.

1 shows a device 1 for adjusting a state of an exhaust gas flow 3 a partially illustrated internal combustion engine 5 a likewise only partially illustrated motor vehicle 7 , The internal combustion engine 5 is an exhaust system 9 with an exhaust system 11 downstream. About a suction pipe 13 becomes the internal combustion engine 5 supplied with air by means of a turbine 15 driven compressor 17 an exhaust gas turbocharger 19 is compressed. With a loading bucket adjustment 21 (VTG) can be the compression of the turbine 15 to be changed. The internal combustion engine 5 can an exhaust gas recirculation 23 (EGR), which is designed as high-pressure exhaust gas recirculation, with an exhaust gas recirculation valve 25 and an exhaust gas recirculation line 27 in which an exhaust gas recirculation cooler 29 is arranged. The exhaust gas of the exhaust gas flow 3 passes through an exhaust manifold 31 to the turbine 15 and in the exhaust system 9 or is in the exhaust manifold 31 in the exhaust gas recirculation 23 diverted.

The over a charge air cooler 33 cooled air or combustion air passes through a throttle valve 35 in an intake collector 37 , in which also the recirculated exhaust gas or a partial flow of the exhaust gas stream 3 empties. The charge pressure of the combustion air is with a charge air sensor 39 detected.

Fresh air or the combustion air passes through an air filter 41 and a fresh air mass sensor 43 to the compressor 17 and from there via a fresh air line 45 for guiding the combustion air or an air mass flow of the combustion air to the intercooler 33 , A control valve 47 controls the air supply via the fresh air line 45 ,

The compressor 17 the exhaust gas turbocharger 19 provides a compressed air source 49 for generating the air mass flow for supplying the internal combustion engine 5 with combustion air. The compressor 17 the compressed air source 49 downstream, the suction tube points 13 for guiding by means of the compressed air source 49 producible air mass flow a branch point 51 on, at the a secondary air line 53 branches. The secondary air line 53 is to Abzwei conditions of a secondary air mass flow 55 to supply a burner connected to it 57 designed with combustion air. It can be seen that both the burner 57 as well as the internal combustion engine 5 equally by means of the compressor 17 the compressed air source 49 can be supplied with combustion air. In 1 is the burner 57 symbolized by a triangle. At the burner 57 it is a the exhaust gas flow 3 of the exhaust system 9 the exhaust system 11 sibling burner, who at a junction 59 in the exhaust stream 3 empties. At the junction 59 dismisses the burner 57 a burner exhaust gas flow in the means of the exhaust line 9 guided exhaust gas flow 3 the internal combustion engine 5 , The burner 57 can by means of a in 1 Not shown device with a fuel, preferably with the same fuel of the internal combustion engine 5 be supplied.

By means of the burner 57 can the fuel together with the secondary air mass flow 55 thermally reacted and for heating via the junction 59 in the exhaust stream 3 be dismissed. Preferably, the burner 57 be operated unteröometrometrisch, so with lack of air, so that the fuel only partially burned in the exhaust stream 3 is initiated. It can be advantageous in the exhaust gas flow of the internal combustion engine 5 to act on a lean exhaust stream, so that by means of the exhaust stream 3 existing residual oxygen a complete implementation of the burner 57 provided fuel can be made. The means of the burner 57 achievable increase in a temperature of the exhaust gas stream 3 can be advantageous for the regeneration of an exhaust gas purification device arranged downstream of the burner 61 the exhaust system 11 serve. In the exhaust gas purification device 61 For example, it may be a particulate filter, preferably a diesel particulate filter 63 , act. For better and / or complete implementation of only partially burned fuel of the burner 57 can the particle filter 63 an oxidation catalyst 65 , In particular, a diesel-oxidation catalyst and a mixer, not shown. Alternatively and / or additionally, it is possible for the particle filter 63 to precede a separate diesel oxidation catalyst.

The particle filter 63 is remote engine in the exhaust system 9 the internal combustion engine 5 arranged. Advantageously, without major thermal losses only by means of the burner 57 a quick heating of the particle filter 63 to its regeneration done. Advantageously, the amount of fuel required for this can be kept to a minimum. Optionally, additional temperature-increasing measures can be carried out.

Alternatively, in particular for a thermal management of the exhaust system 11 , it is possible to use several of the burners 57 in the exhaust system 11 provided. Besides, it is possible to use the burner 57 or the point of confluence 59 of the burner 57 at another location of the exhaust system 11 provide, for example, in front of an SCR catalyst 67 , in front of a NOX storage catalytic converter 69 and / or in front of a close-coupled, oxidation catalyst 71 , In 1 are exemplary of the oxidation catalyst 71 close to the engine, this is followed by the NOX catalyst 69 and this downstream of the SCR catalyst 67 the exhaust system 11 shown.

In the internal combustion engine 5 it can be a lean exhaust stream 3 producing internal combustion engine act, for example, a diesel engine or a lean-burn engine with spark ignition.

2 shows another device 1 for adjusting a state of an exhaust gas flow 3 an internal combustion engine 5 , In the following, only the differences from the illustration according to 1 received.

For the control and / or regulation are various actuating and / or measuring elements of the device 1 an engine control unit 73 assigned. Corresponding active compounds are by means of dotted lines in 2 symbolizes.

Advantageously, by means of the engine control unit 73 a pressure gradient between the branch point 51 and the point of confluence 59 set and / or raised. For this purpose, by means of the engine control unit 73 a variable compressor geometry 75 (VCG) of the compressor 17 the exhaust gas turbocharger 19 be set. In addition, a variable turbine geometry 77 (VTG) of the turbine 15 the exhaust gas turbocharger 19 be set. By means of the variable compressor geometry 75 can one in the suction tube 13 Generable boost pressure 79 be enlarged, by means of the suction tube 13 also at the junction 51 is applied, so that the pressure gradient to the burner 57 increased. Similarly, by means of the variable turbine geometry 77 a relaxation pressure difference of the turbine 15 be increased, with an exhaust back pressure in the direction of the internal combustion engine 5 increases and downstream the pressure of the exhaust stream 3 reduced, which also at the confluence point 59 of the burner 57 is applied, so that the pressure difference increases.

The branch office 51 downstream is in the suction pipe 13 a first throttle body 81 with a throttle 83 connected. The first throttle body 81 can by means of the engine control unit 73 is be controlled. Advantageously, by means of the throttle valve 83 the at the branch point 51 prevailing boost pressure 79 compared to one of the internal combustion engine 5 supplied boost pressure in the intake manifold 13 be increased, so that in consequence the pressure gradient to the burner 57 increased.

The exhaust system 9 points at the junction 59 of the burner 57 upstream of a second throttle body 85 with an exhaust flap 87 on. The second throttle body 85 can by means of the engine control unit 73 be controlled. Advantageously, by means of the exhaust flap 87 an exhaust back pressure of the internal combustion engine 5 be increased, being downstream of the exhaust flap 87 a pressure of the exhaust stream 3 humiliated, who also at the point of confluence 59 is applied, so that advantageously the pressure gradient between the branch point 51 and the point of confluence 59 elevated.

The secondary air line 53 can be a regulatory organ 89 For example, a valve 91 exhibit. The valve 91 can by means of the engine control unit 73 be controlled and used to set the secondary air mass flow 55 , Advantageously, the control organ 89 the secondary air mass flow 55 limit, if the resulting pressure gradient between the branch point 51 and the point of confluence 59 is higher than to a desired operation of the burner 57 necessary, in particular also to set a Brennerlambda value. In addition, the valve can 91 of the regulatory body 89 the secondary air line 53 be closed, if an operation of the burner 57 not wanted.

The exhaust gas recirculation 23 , which in the present case is designed as high-pressure exhaust gas recirculation, has the exhaust gas recirculation valve 25 on. The exhaust gas recirculation valve 25 is by means of the engine control unit 73 controllable. Advantageously, to increase the exhaust back pressure upstream of the turbine 15 the exhaust gas turbocharger 19 the exhaust gas recirculation valve 25 be closed, wherein advantageously a the compressor 17 available power is increased, causing an increase in boost pressure 79 can cause. For measuring the boost pressure and / or a charge air temperature after charge air cooling 33 can the suction tube 13 a measuring device 93 ( 2 ) associated with the engine control unit 73 communicates.

Optionally, it is possible in the high pressure region of the exhaust stream 3 So in front of the turbine 15 the exhaust gas turbocharger 19 an exhaust side stream line 95 for guiding a secondary exhaust gas flow 97 divert. The secondary exhaust gas flow 97 or the exhaust side stream line 95 , in the 2 shown dotted, can in front of the burner 57 in the secondary air line 53 open out. Advantageously, thereby a temperature of the secondary air mass flow 55 be raised. Furthermore, parameters of a mixture formation of the burner 57 to be influenced. For controlling and / or regulating the secondary exhaust gas flow 97 indicates the exhaust side bypass pipe 95 another regulatory body 99 with a valve 101 on. The valve 101 can by means of the engine control unit 73 be controlled.

Optionally, it is possible to use the secondary air line 53 an air mass meter 103 or mass flow meter for measuring the secondary air mass flow 55 assigned. The air mass meter 103 can the engine control unit 73 be assigned. An air mass meter of the measuring device 93 as well as the air mass meter 103 For example, they may be designed as a hot wire anemometer and / or as an ultrasonic Doppler anemometer.

Advantageously, despite a remote engine arrangement of the particulate filter 63 this will be regenerated. An otherwise disadvantageous motor post-injection can be reduced to a tolerable level or is completely dispensable. Advantageously, an undesirable entry of fuel into an engine oil of the internal combustion engine 5 be prevented. This also makes the internal combustion engine advantageous 5 better suited for operation with biomass fuels.

Advantageously, the burner 57 by means of the secondary air mass flow 55 of the compressor 17 be supplied with combustion air. Advantageously, the remote engine particulate filter 63 by means of the burner 57 be regenerated. A conceivable embodiment of the exhaust system 11 sees an SCR catalyst 67 , this downstream the burner 57 and this downstream of the particle filter 63 in front. The removal of the secondary air mass flow 55 takes place after the compressor 17 the compressed air source 49 , Alternatively and / or additionally, it is conceivable, the secondary air line 53 Assign a compressed air storage, not shown. By means of the compressed air reservoir can advantageously operating conditions of a low pressure gradient and / or negative pressure gradient between the branch point 51 and the point of confluence 59 be bridged. The compressed air reservoir can do this by its own means of the engine control unit 73 have controllable control element.

Advantageously, an otherwise necessary secondary air pump for providing the secondary air mass flow 55 be waived.

In the internal combustion engine 5 it is a by means of the exhaust gas turbocharger 19 supercharged turbo engine, which advantageously already existing compressed air for providing the secondary air mass flow 55 can be used. al ternatively and / or additionally, it is conceivable, another device for compressed air generation as a compressed air source 49 provide, for example, a compressor, a Komprex-loader and / or a combination of a compressor and a compressed air reservoir. The secondary air mass flow 55 can be beneficial after the intercooler 33 be removed so that it has a higher density, so that the burner 57 can achieve a higher performance.

Alternatively and / or additionally, the burner 57 advantageous in addition to the regeneration of the particulate filter 63 for a temperature control of the entire exhaust system 11 the internal combustion engine 5 be used. By the use of the burner 57 For this application, too, the necessary fuel consumption for the exhaust gas temperature management and the regeneration of the particulate filter can be achieved 63 to reduce.

It is conceivable, a required mixture composition of the burner 57 by means of a variation of a fuel mass supplied to the burner at a constant secondary air mass flow or by varying the secondary air mass flow supplied to the burner 55 to realize at constant fuel quantity and / or in combination of both variations.

Advantageously, a λ value or an air ratio of the burner 57 by means of the control organ 89 and / or the other regulatory body 99 be set.

The burner 57 can be used for thermal management of the NOX storage catalytic converter 69 and / or the SCR catalyst 67 be used. For this purpose, the burner 57 this be upstream.

Advantageously, by means of the burner 57 also a cold start behavior of the internal combustion engine 5 be optimized.

For better implementation of the fuel of the burner 57 , In particular, if this is operated undersochoeometrisch, the particulate filter 63 the oxidation catalyst 65 and / or an unspecified mixer be connected upstream.

The valve 91 of the regulatory body 89 can be analogous to the high-pressure exhaust gas recirculation valve 25 be educated.

To increase a boost pressure of the compressor 17 the exhaust gas turbocharger 19 can throttling the air mass flow by means of the throttle 83 and / or driving the high-pressure exhaust gas recirculation valve 25 to reduce an exhaust gas recirculation rate and / or a control of the exhaust gas turbocharger, in particular the variable compressor geometry 75 of the compressor 17 and / or the variable turbine geometry 77 the turbine 15 the exhaust gas turbocharger 19 serve.

For a compressed air source 49 With a mechanical compressor, a compressor speed can be increased to increase the boost pressure.

Furthermore, to increase the pressure gradient between the branch point 51 and the point of confluence 59 Motor measures conceivable, in particular an increase of an idling speed of the internal combustion engine 5 , an increase in the exhaust gas temperature of the exhaust stream 9 in front of the turbine 15 and / or a tolerable post-injection of the internal combustion engine 5 , In addition, as a motor measure earlier opening of exhaust valves of the internal combustion engine 5 conceivable, which is also a temperature of the exhaust stream 9 elevated.

1

contraption

3

exhaust gas flow

5

Internal combustion engine

7

motor vehicle

9

exhaust gas line

11

exhaust system

13

suction tube

15

turbine

17

compressor

19

turbocharger

21

Bucket adjustment

23

Exhaust gas recirculation

25

Exhaust gas recirculation valve

27

Exhaust gas recirculation line

29

Exhaust gas recirculation cooler

31

exhaust manifold

33

Intercooler

35

throttle

37

intake manifold

39

Charge air sensor

41

air filter

43

Fresh air mass sensor

45

Fresh air line

47

control valve

49

Compressed air source

51

branching point

53

Secondary air line

55

Secondary air mass flow

57

burner

59

junction point

61

exhaust gas cleaning device

63

Diesel Particulate Filter

65

oxidation catalyst

67

SCR catalyst

69

NOX storage catalyst

71

oxidation catalyst

73

Engine control unit

75

variable compressor geometry

77

variable turbine geometry

79

boost pressure

81

first throttle member

83

throttle

85

second throttle member

87

exhaust flap

89

regulating element

91

Valve

93

measuring device

95

Exhaust bypass line

97

Exhaust bypass

99

regulating element

101

Valve

103

Air flow sensor

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

• - DE 102004022186 [0002]
• - DE 4443133 A1 [0002]
• - DE 3837472 A1 [0003]
• - DE 102006009943 A1 [0004]

Claims (10)

Method for adjusting a state of an exhaust gas line ( 9 ) an internal combustion engine ( 5 ) of a motor vehicle ( 7 ) guided exhaust gas flow ( 3 ), with a compressed air source ( 49 ) for generating a in a fresh air line ( 45 ) guided air mass flow for supplying the internal combustion engine ( 5 ) with combustion air, by means of a at a junction ( 59 ) in the exhaust stream ( 3 ) burner ( 57 ), with: - branching off a secondary air mass flow ( 55 ) at a branch point ( 51 ) of the fresh air line ( 45 ) downstream of the compressed air source ( 49 ) in the burner ( 57 ) for the supply of the burner ( 57 ) with combustion air, - raising or setting a pressure gradient from the branch point ( 51 ) to the point of 59 ). Method according to claim 1, with at least one of the following: raising the pressure gradient by throttling the air mass flow, raising the pressure gradient by throttling the air mass flow by means of a compressed air source 49 ) and the branch office ( 51 ) in the fresh air line ( 45 ) downstream first throttle body ( 81 ). Method according to one of the preceding claims, with at least one of the following: - raising the pressure gradient by throttling the exhaust gas flow ( 3 ), - raising the pressure gradient by throttling the exhaust gas flow ( 3 ) by means of one of the confluence points ( 59 ) in the exhaust gas line ( 9 ) upstream second throttle body ( 85 ). Method according to one of the preceding claims, comprising at least one of the following: - raising the pressure gradient by driving a variable turbine geometry ( 77 ) (VTG) of a turbine ( 15 ) of an exhaust gas turbocharger ( 19 ) of the compressed air source ( 49 ), - raising the pressure gradient by driving a variable compressor geometry ( 75 ) (VCG) of a compressor ( 17 ) of the compressed air source ( 49 ). Method according to the preceding claim, with - raising the pressure gradient of the exhaust gas turbocharger by reducing an exhaust gas recirculation rate of a high-pressure exhaust gas recirculation ( 23 ). Method according to one of the preceding two claims, comprising: - supplying a partial flow of the exhaust gas stream ( 3 ) in the burner ( 57 ) by branching off the partial flow in front of the turbine ( 15 ) of the exhaust gas turbocharger ( 19 ) in an exhaust side stream ( 95 ). Method according to one of the preceding claims, comprising: - raising the pressure gradient by means of raising a rotational speed of a mechanical supercharger of the compressed air source ( 49 ). Method according to one of the preceding claims, comprising: raising the pressure gradient by means of at least one of the following engine measures of the internal combustion engine ( 5 ): - increasing an idling speed of the internal combustion engine ( 5 ), - increasing a temperature of the exhaust gas flow ( 3 ) in front of the turbine ( 15 ) of the exhaust gas turbocharger ( 19 ), - raising the temperature by means of a post-injection, - earlier opening of exhaust valves of the internal combustion engine ( 5 ). Method for setting a state of an exhaust gas flow ( 3 ) an internal combustion engine ( 5 ) of a motor vehicle ( 7 ), in particular according to one of the preceding claims, with a compressed air source ( 49 ) for generating an air mass flow for supplying the internal combustion engine ( 5 ) with combustion air, by means of a at a junction ( 59 ) in the exhaust stream ( 3 ) burner ( 57 ), with: - branching off a secondary air mass flow ( 55 ) at a branch point ( 51 ) of the fresh air line ( 45 ) downstream of the compressed air source ( 49 ) and downstream of a compressed air source ( 49 ) downstream charge air cooler ( 33 ) in the burner ( 57 ) for the supply of the burner ( 57 ) with combustion air. Contraption ( 1 ) for setting a state of an exhaust gas flow ( 3 ) an internal combustion engine ( 5 ) of a motor vehicle ( 7 ), with: - one at a junction ( 59 ) in the exhaust stream ( 3 ) burner ( 57 ), - a compressed air source ( 49 ) for generating an air mass flow for supplying the internal combustion engine ( 5 ) and the burner ( 57 ) with combustion air, set up, designed and / or constructed for carrying out a method according to one of the preceding claims.