DE102009051027B4 - Drive unit with a diesel internal combustion engine and exhaust gas recirculation as well as a method for operating such a drive unit - Google Patents

Abstract

Drive unit (1) with a diesel internal combustion engine (2), an exhaust gas turbocharger (12), a charge air cooler (23) connected downstream of a compressor (20) of the exhaust gas turbocharger (12) and an exhaust gas recirculation system (27), the compressor (20) and the charge air cooler ( 23) belong to an intake tract (6) of the diesel engine (2) and a three-way catalytic converter (15) is arranged in an exhaust tract (7) of the diesel engine (2), characterized in that exhaust gas from the Exhaust tract (7) can be removed upstream of the three-way catalytic converter (15) and can be introduced into the intake tract (6) by means of a first exhaust gas recirculation line (28) before the charge air cooler (23) and by means of a second exhaust gas recirculation line (29) after the charge air cooler (23) is, wherein the first exhaust gas recirculation line (28, 29) has an exhaust gas aftertreatment device (33) and the second exhaust gas recirculation line (29) upstream of the exhaust gas aftertreatment device (33) from the first exhaust return line (28) branches off.

Description

The invention relates to a drive unit with a diesel internal combustion engine, an exhaust gas turbocharger, a charge air cooler connected downstream of a compressor of the exhaust gas turbocharger and an exhaust gas recirculation, the compressor and the charge air cooler belonging to an intake tract of the diesel internal combustion engine and a three-way exhaust gas catalytic converter being arranged in an exhaust tract of the diesel internal combustion engine. The invention also relates to a method for operating a drive unit.

Drive units of the type mentioned are known from the prior art. In particular for use in a motor vehicle, the diesel internal combustion engine is charged with the exhaust gas turbocharger in order to increase its efficiency and its output. The exhaust gas turbocharger consists of a turbine and a compressor. The turbine is assigned to an exhaust gas tract of the diesel internal combustion engine and takes energy from the exhaust gas carried in this in order to drive the compressor. Fluid, in particular fresh air, supplied to the diesel internal combustion engine is compressed with the compressor, so that more oxygen is available during a combustion taking place in the diesel internal combustion engine. However, when the air is compressed by means of the compressor, its temperature increases. The charge air cooler is therefore provided downstream of the compressor of the exhaust gas turbocharger in order to cool down the air heated by the compression again. In this way, the performance of the diesel internal combustion engine can be increased further.

The exhaust gas recirculation is provided in order to reduce the exhaust gas emissions of the diesel internal combustion engine. The exhaust gas recirculation is designed as a so-called external exhaust gas recirculation, in which exhaust gas discharged from the diesel engine is returned to the intake tract. Exhaust gas from the exhaust gas tract of the diesel internal combustion engine should therefore be returned to its intake tract. This increases the proportion of exhaust gas in the intake air. The speed of combustion in the diesel internal combustion engine thus slows down, with the maximum temperatures reached during combustion falling at the same time. Because the formation of nitrogen oxides (NO _x ) during combustion is highly dependent on temperature, the nitrogen oxide emissions of the diesel internal combustion engine can be reduced in this way. The potential for reducing nitrogen oxide emissions increases with the return rate, i.e. the amount of exhaust gas returned to the intake tract.

A so-called three-way catalytic converter can be used to reduce the amount of pollutants released into the surroundings of the drive unit, in particular the amount of NO _x , for drive units with gasoline internal combustion engines. Such three-way catalytic converters are also known from the prior art. The prerequisite for this is an essentially constant fuel-air mixture in the stoichiometric ratio λ = 1. The three-way catalytic converters usually cannot be used for diesel internal combustion engines, since in these there is an excess of oxygen in the exhaust gas, which reduces the nitrogen oxide in the Three-way catalytic converter prevents or reduces its efficiency. In diesel internal combustion engines, an SCR catalytic converter is often used to (further) reduce nitrogen oxide emissions. A selective catalytic reduction (SCR) takes place in this. In this case, ammonia, for example in the form of an aqueous urea solution, is usually introduced into the exhaust gas tract upstream of the SCR catalytic converter. Such a procedure is complex in comparison with the use of a three-way catalytic converter.

The document is from the prior art FR 2 916 020 A1 known. This describes an intake system for a motor vehicle engine, comprising an engine, an exhaust line for the exhaust gases, a circulation path for the low-pressure exhaust gases, this circulation being controlled by a circulation valve and a first high-temperature heat exchanger on the intake path in front of the engine inlet, which operates at a first temperature level, It is provided that the system includes a second low-temperature heat exchanger on the intake path, which operates at a second, lower temperature level.

The publication also describes DE 10 2005 052 496 A1 an internal combustion engine with an exhaust gas turbocharger comprising a compressor and an exhaust gas-driven turbine in the intake tract, the compressor being followed by a charge air cooler, from the exhaust gas tract a first exhaust gas recirculation line on the turbine and a second valve-controlled exhaust gas recirculation line in the intake tract on the compressor, the second exhaust gas recirculation line opening a branch that is connected to the high pressure side of the compressor via a switching valve in the second exhaust gas recirculation line in an operating state with medium load.

In addition, apparently the print DE 10 2007 046 158 A1 a catalytically active particle filter containing a filter body and a catalytically active coating, which consists of two layers arranged one above the other, the second layer being in direct contact with the incoming exhaust gas and completely covering the first layer on the exhaust side, both layers containing aluminum oxide, and the Aluminum oxide catalytically activated in the first layer with palladium while the second layer contains rhodium as a catalytically active component.

It is the object of the invention to present a drive unit in which a simple and efficient reduction in pollutants, in particular NO _x reduction, is possible in diesel internal combustion engines.

According to the invention, this is achieved with a drive unit having the features of claim 1. It is provided that exhaust gas can be removed from the exhaust gas tract by means of exhaust gas recirculation and introduced into the intake tract by means of a first exhaust gas recirculation line upstream of the charge air cooler and by means of a second exhaust gas recirculation line after the charge air cooler, the first exhaust gas recirculation line having an exhaust gas treatment device and the second exhaust gas recirculation line upstream of the exhaust gas treatment device the first exhaust gas recirculation line branches off.

The exhaust gas recirculation has both the first and the second exhaust gas recirculation line. As stated above, exhaust gas can be removed from the exhaust gas tract by means of the exhaust gas recirculation. Via the first exhaust gas recirculation line, the extracted exhaust gas can be introduced into the intake tract before the charge air cooler and by means of the second exhaust gas recirculation line after the charge air cooler. It can also be provided that the exhaust gas is withdrawn using the first and / or the second exhaust gas recirculation line. It is therefore not absolutely necessary to first remove the exhaust gas and then feed it to the first and / or the second exhaust gas recirculation line. Rather, both the first and the second exhaust gas recirculation line can be connected directly to the exhaust gas tract and / or the intake tract. The exhaust gas recirculation described enables the diesel internal combustion engine to be operated with comparatively low lambda values (λ ≈ 1, stoichiometric range) without increasing the amount of soot emitted. The amount of carbon monoxide (CO) and hydrocarbon (HC), which normally increases with such a procedure, can also be kept at a constant or only slightly increased level. The performance of the diesel internal combustion engine also does not decrease despite operation in the stoichiometric range. The diesel internal combustion engine is consequently operated essentially in the stoichiometric range, that is to say with λ ≈ 1 or in the range of 0.90 λ 1.10, in particular 0.97 λ 1.03. This allows the exhaust gas from the diesel engine to be post-treated or cleaned efficiently in a three-way catalytic converter. For this reason, the three-way catalytic converter is provided in the exhaust tract.

The invention provides that the first exhaust gas recirculation line has an exhaust gas aftertreatment device. The first exhaust gas recirculation line opens before the charge air cooler into the intake tract, which is to be protected from contamination by the recirculated exhaust gas. The exhaust gas aftertreatment device provided in particular for this purpose has, for example, a catalytic converter and / or a filter, in particular a diesel particle filter. In addition, an exhaust gas aftertreatment device can be provided in the second exhaust gas recirculation line. The exhaust gas recirculated through the first and / or the second exhaust gas recirculation line can thus be cleaned by means of the exhaust gas aftertreatment device before it reaches the intake tract of the diesel internal combustion engine. The aftertreatment of the recirculated exhaust gas thus preferably includes filtering to separate soot particles from the recirculated exhaust gas with the aid of an open or closed particle filter, in particular a diesel particle filter. In addition, an oxidation of carbon monoxide and unburned hydrocarbons can advantageously also be carried out, expediently either with the aid of an oxidation catalyst or with the aid of a suitable catalytic coating of the particle filter. If a particle filter is provided, it is preferably provided with a regeneration device with which the soot particles in the particle filter can be burned if necessary. The regeneration device advantageously comprises at least one pressure and / or temperature sensor, with the aid of which the loading of the particle filter with particles or the regeneration can be monitored. A pressure sensor and a temperature sensor are preferably provided in front of and behind the particle filter. The two pressure sensors are used to determine the exhaust gas back pressure or the difference between the pressures upstream and downstream of the particle filter. The value determined in this way is evaluated by a control device, in particular an engine control device of the diesel internal combustion engine, in order to initiate the regeneration of the particle filter when a predetermined exhaust gas back pressure is exceeded. The temperature sensors are used in particular to monitor regeneration.

According to an advantageous development of the invention, the three-way catalytic converter is provided downstream or upstream of the turbine of the exhaust gas turbocharger. In the first case, there is essentially a low-pressure exhaust gas recirculation, in the latter case a high-pressure exhaust gas recirculation. If the three-way catalytic converter is arranged downstream of the turbine, the exhaust gas has already been expanded in this and is therefore at a low pressure level. For this reason, an exhaust gas compressor must be provided for such an exhaust gas recirculation in order to reactivate the exhaust gas to bring a higher pressure level. This compressor can be operated in essentially any way. If the three-way catalytic converter is arranged upstream of the turbine, the exhaust gas is still at a high pressure level and can be introduced into the intake tract of the diesel engine without any problems.

An advantageous further development provides that the three-way catalytic converter is integrated in an exhaust gas particle filter. In addition to the three-way catalytic converter, the exhaust gas particle filter is also provided in the exhaust tract. The three-way catalytic converter and the exhaust particle filter can be integrated with one another, for example, arranged in a common housing.

A further embodiment of the invention provides that the three-way catalytic converter is produced by means of a coating on the exhaust particle filter. The coating, by means of which the effect of the three-way catalytic converter is achieved, is applied in the exhaust particle filter.

According to a further development of the invention, it is provided that the three-way exhaust gas catalytic converter and / or the exhaust gas particle filter is integrated with a further exhaust gas aftertreatment device, in particular an exhaust gas oxidation catalytic converter, in a common housing. Consequently, at least one further exhaust gas aftertreatment device is provided in the exhaust tract. This can be arranged upstream or downstream (based on the exhaust gas in the exhaust gas tract) of the three-way catalytic converter and / or the exhaust gas particle filter. The common housing is provided in which the further exhaust gas aftertreatment device is provided together with the three-way exhaust gas catalytic converter and / or the exhaust gas particle filter - they are therefore accommodated in a caning.

A preferred development provides that a lambda probe is assigned to the three-way catalytic converter. By means of the lambda probe, the composition of the fuel-air mixture which is fed to the diesel internal combustion engine can be adjusted in a controlling and / or regulating manner. Either a step probe can be used which only reacts to a certain lambda value, for example λ = 1, and thus only enables regulation to a single lambda value. Alternatively, however, a broadband probe can also be provided, by means of which it can be established which lambda value is actually present in the exhaust gas of the diesel internal combustion engine.

Another embodiment of the invention provides that the diesel internal combustion engine can be operated by means of the lambda probe with a lambda value in a range from 0.9 to 1.1, in particular 0.97 to 1.03. In the latter area in particular, it can be assumed that the three-way catalytic converter is functioning properly. For this reason, the composition of the fuel-air mixture is adjusted in such a way that the lambda value is in the range mentioned.

According to the invention it is provided that the second exhaust gas recirculation line branches off from the first exhaust gas recirculation line before the exhaust gas aftertreatment device. It can therefore be provided that the exhaust gas is removed from the exhaust gas tract of the diesel internal combustion engine via the first exhaust gas recirculation line. The only decisive factor, however, is that the second exhaust gas recirculation line branches off from this, which enables the exhaust gas to be introduced before and after the charge air cooler via the two exhaust gas recirculation lines. It is provided that the second exhaust gas recirculation line branches off from the first exhaust gas recirculation line before the exhaust gas aftertreatment device. In this way, cleaned exhaust gas is fed to the intake tract of the diesel engine upstream of the charge air cooler and uncleaned exhaust gas after the charge air cooler. At least this prevents the charge air cooler from being contaminated by the supply of uncleaned exhaust gas, which would impair its efficiency.

A further development of the invention provides that an exhaust gas control valve is provided in the first exhaust gas recirculation line and / or the second exhaust gas recirculation line. The exhaust gas control valve is, for example, a cross section adjustment device. The exhaust gas control valve can be used to adjust and / or regulate the amount of exhaust gas that reaches the first exhaust gas recirculation line and / or the second exhaust gas recirculation line. It can be provided, for example, that a first exhaust gas control valve is provided in the first exhaust gas recirculation line, with which the common exhaust gas quantity from the first and second exhaust gas recirculation line can be adjusted. A second exhaust gas control valve can then be provided, which can in particular be designed as a three-way valve. This allows the exhaust gas to be divided between the first and the second exhaust gas recirculation line. Such an exhaust gas control valve is preferably provided upstream or in front of the exhaust gas aftertreatment device.

According to an advantageous further development of the invention, at least one supply air throttle valve, in particular a three-way valve, is provided in the intake tract. The supply air throttle valve is designed, for example, as a cross-section adjustment device and allows the amount of supply air supplied to the diesel internal combustion engine to be adjusted. The supply air can at this point there may already be an exhaust-air mixture. The supply air throttle valve can be designed, for example, as a three-way valve, which makes it possible, for example, to adjust the ratio of the exhaust gas from the second exhaust gas recirculation line to the exhaust gas-air mixture from the intake tract, which is fed to the diesel internal combustion engine.

An advantageous embodiment of the invention provides that the first exhaust gas recirculation line opens into the intake tract before the supply air control valve and / or the second exhaust gas recirculation line after the supply air control valve. If the first exhaust gas recirculation line is connected to the intake tract upstream of the supply air control valve, then both the fresh air volume and the exhaust gas volume supplied through the first exhaust gas recirculation line are set by means of this. Additionally or alternatively, it is possible for the second exhaust gas recirculation line to open into the intake tract downstream of the air supply valve. In this case, it is not possible by means of the supply air control valve to adjust the amount of exhaust gas introduced into the intake tract via the second exhaust gas recirculation line.

Additionally or alternatively, a heat exchanger is provided in the first and / or the second exhaust gas recirculation line. The temperature of the recirculated exhaust gas can be reduced by means of the heat exchanger. This means that the recirculated exhaust gas has a lower temperature and has to be heated during the combustion inside the diesel internal combustion engine. As a result, the temperature reached during combustion decreases, which reduces the amount of nitrogen oxide emitted by the diesel internal combustion engine.

The invention further relates to a method for operating a drive unit, in particular according to the above statements, the drive unit having a diesel internal combustion engine, an exhaust gas turbocharger, a charge air cooler connected downstream of a compressor of the exhaust gas turbocharger and an exhaust gas recirculation system, the compressor and the charge air cooler belonging to an intake tract of the diesel internal combustion engine and A three-way catalytic converter is arranged in an exhaust tract of the diesel internal combustion engine. It is provided that exhaust gas can be withdrawn from an exhaust tract of the diesel engine by means of exhaust gas recirculation and introduced into the intake tract by means of a first exhaust gas recirculation line before the charge air cooler and by means of a second exhaust gas recirculation line after the charge air cooler, the first exhaust gas recirculation line having an exhaust gas aftertreatment device and the second exhaust gas recirculation line upstream the exhaust gas aftertreatment device branches off from the first exhaust gas recirculation line.

It can also be provided that the exhaust gas aftertreatment device comprises a three-way exhaust gas recirculation catalytic converter in the first and / or the second exhaust gas recirculation line. This three-way exhaust gas recirculation catalytic converter can be integrated into an exhaust gas recirculation particulate filter. In addition to the three-way exhaust gas recirculation catalytic converter, the exhaust gas recirculation particle filter can also be provided in the first and / or second exhaust gas recirculation line. The three-way exhaust gas recirculation catalytic converter and the exhaust gas recirculation particle filter can be integrated with one another, for example, arranged in a common housing.

Finally, the three-way exhaust gas recirculation catalytic converter can be produced by means of a coating on the exhaust gas recirculation particle filter. The coating is applied in the exhaust gas recirculation particle filter, by means of which the effect of the three-way exhaust gas recirculation catalytic converter is achieved.

• Figur eine schematische Darstellung eines Antriebsaggregats.

The invention is explained in more detail below with reference to the embodiment shown in the drawing, without restricting the invention. It shows the only one

• Figure is a schematic representation of a drive unit.

The figure shows a drive unit 1 with a diesel engine 2 , which (purely by way of example) have two cylinder banks 3 and 4th with three cylinders each 5 disposes. The diesel internal combustion engine 2 has an intake duct 6th and an exhaust tract 7th on. There are in the intake tract 6th those areas of the drive unit 1 assigned to the supply of fluid, in particular fresh air, in the diesel engine 2 serve. The exhaust tract 7th are on the other hand exhaust-gas-carrying areas of the drive unit 1 assigned, so in particular exhaust manifold 8th and 9 of the cylinder banks 3 and 4th . Through the exhaust manifold 8th and 9 exhaust gas flows out of the cylinders 5 following the combustion carried out in these. Downstream the exhaust manifold 8th and 9 is an exhaust manifold 10 provided which the exhaust gas of the exhaust manifold 8th and 9 merges and together a turbine 11 of an exhaust gas turbocharger 12 feeds. In the turbine 11 the exhaust gas is expanded and thus brought to a lower pressure. Downstream of the turbine 11 is an exhaust aftertreatment device 13th in the form of an exhaust gas oxidation catalyst 14th provided to which a three-way catalytic converter 15th and an exhaust particulate filter 16 connect that in a housing 17th are arranged. Here is the three-way catalytic converter 15th by means of a coating on the exhaust particle filter 16 generated. Downstream of the three-way catalytic converter 15th as well as the exhaust particle filter 16 becomes the exhaust gas of the diesel internal combustion engine 2 in an environment 18th of the drive unit 1 dismiss.

The turbine 11 of the exhaust gas turbocharger 12 serves to use a shaft 19th a compressor 20th of the intake tract 6th to drive. The compressor 20th brings about an air filter 21st sucked in air to a higher pressure level. The air compressed in this way is then used by the diesel engine 2 fed. The through the air filter 21st The amount of air drawn in can be measured by means of an air mass measuring device 22nd , for example a hot film air mass measuring device, can be determined. The means of the compressor 20th compressed air passes through a charge air cooler 23 and a supply air throttle valve 24 to air distributors 25th and 26th of the cylinder banks 3 and 4th , via which supply air into the cylinder 5 to carry out the combustion.

The drive unit 1 also has exhaust gas recirculation 27 . This allows exhaust gas from the exhaust tract 7th , especially the exhaust manifold 10 , removed and the intake tract 6th are fed. For this purpose there is both a first exhaust gas recirculation line 28 as well as a second exhaust gas recirculation line 29 intended. The first exhaust gas recirculation line 28 is to the exhaust manifold 8th and 9 or to the exhaust manifold 10 connected (exhaust gas extraction point 30th ). At the exhaust gas extraction point 30th Exhaust gas enters the first exhaust gas recirculation line 28 . Downstream of the exhaust gas extraction point 30th has the first exhaust gas recirculation line 28 a first exhaust gas control valve 31 on. With this, the amount of exhaust gas can be adjusted, which the exhaust tract 7th removed and the intake tract 6th the diesel engine 2 is fed. Downstream of the first exhaust gas control valve 31 branches off the second exhaust gas recirculation line 29 from the first exhaust gas recirculation line 28 from. At this point is a second exhaust gas control valve 32 , which is designed as a three-way valve, is provided, via which the second exhaust gas recirculation line 29 to the first exhaust gas recirculation line 28 connected. With the help of the second exhaust gas control valve 32 can be set in a controlling and / or regulating manner, which amount of exhaust gas through the first exhaust gas recirculation line 28 or the second exhaust gas recirculation line 29 the intake tract 6th is fed. Downstream of the second exhaust gas control valve 32 is in the first exhaust gas recirculation line 28 an exhaust aftertreatment device 33 intended. This consists of an exhaust gas recirculation particle filter 34 and a three-way exhaust gas recirculation catalyst 35 . The exhaust gas recirculation particulate filter 34 as well as the three-way exhaust gas recirculation catalytic converter 35 are in one housing 36 intended. This is the three-way exhaust gas recirculation catalytic converter 35 by coating the exhaust gas recirculation particulate filter 34 generated. The three-way exhaust gas recirculation catalytic converter 35 is therefore in the exhaust gas recirculation particulate filter 34 integrated. Further downstream is a heat exchanger 37 provided, which for cooling the through the first exhaust gas recirculation line 28 recirculated exhaust gas is used.

It is provided that the first exhaust gas recirculation line 28 at an outlet point 38 in front of the intercooler 23 and the second exhaust gas recirculation line 29 at an outlet point 39 after the intercooler 23 in the intake tract 6th merge. The point of discharge is here 38 the first exhaust gas recirculation line 28 but downstream (in relation to the air) of the compressor 20th of the exhaust gas turbocharger 12 arranged. Both exhaust gas recirculation lines 28 and 29 So open out at the mouth 38 and 39 in the intake tract 6th one in which compressed air, i.e. air at a high pressure level, is present. It can be the intake tract 6th via the first exhaust gas recirculation line 28 cleaned exhaust gas and via the second exhaust gas recirculation line 29 uncleaned exhaust gas are fed. Furthermore, the drive unit 1 a control and / or regulating device 40 on. By means of this both the function of the diesel internal combustion engine 2 as well as the position of the supply air throttle valve 24 , the exhaust control valves 31 and 32 as well as the operation of the heat exchanger 37 and the intercooler 23 controlled and / or regulated.

With the drive unit described above 1 or its exhaust gas recirculation 27 it is possible in an extremely efficient way to use the diesel engine 2 to operate. This can be done in particular in such a way that a mixture with an essentially stoichiometric ratio of fuel and air is used for combustion. This means that in the exhaust gas of the diesel engine 2 it contains little or no unburned oxygen. This can be used for exhaust gas aftertreatment, in particular to reduce the in the environment 18th emitted nitrogen oxide, the three-way catalytic converter 15th be used. Also through the first exhaust gas recirculation line 28 Recirculated exhaust gas can be achieved by means of a corresponding three-way exhaust gas recirculation catalytic converter 35 be treated. In particular, through good homogenization of the exhaust gas recirculation 27 , the high cooling capacity - especially by means of the intercooler 23 and the heat exchanger 37 - as well as good combustion behavior within the diesel internal combustion engine 2 a lambda value of about 1 can be set without reducing the carbon monoxide, soot and / or hydrocarbon emissions of the drive unit 1 significantly deteriorated and without any losses in terms of the performance of the drive unit 1 to make noticable. Especially when accelerating the diesel engine 2 can by a suitable control and / or regulating device 40 In analogy to a gasoline engine, a lambda value of approximately 1 is set and the amount of nitrogen oxides emitted is reduced.

List of reference symbols

1

Drive unit

2

Diesel internal combustion engine

3

Cylinder bank

4th

Cylinder bank

5

cylinder

6th

Intake tract

7th

Exhaust tract

8th

Exhaust manifold

9

Exhaust manifold

10

Exhaust manifold

11

turbine

12

Exhaust gas turbocharger

13

Exhaust aftertreatment device

14th

Exhaust oxidation catalyst

15th

Three-way catalytic converter

16

Exhaust particulate filter

17th

casing

18th

Surroundings

19th

wave

20th

compressor

21st

Air filter

22nd

Air mass measuring device

23

Intercooler

24

Supply air throttle valve

25th

Air distributor

26th

Air distributor

27

Exhaust gas recirculation

28

first exhaust gas recirculation line

29

second exhaust gas recirculation line

30th

Exhaust gas extraction point

31

first exhaust gas control valve

32

second exhaust control valve

33

Exhaust aftertreatment device

34

Exhaust gas recirculation particulate filter

35

Three-way exhaust gas recirculation catalytic converter

36

casing

37

Heat exchanger

38

Mouth points

39

Mouth point

40

Control and / or regulating device

Claims (11)

Drive unit (1) with a diesel internal combustion engine (2), an exhaust gas turbocharger (12), a charge air cooler (23) connected downstream of a compressor (20) of the exhaust gas turbocharger (12) and an exhaust gas recirculation system (27), the compressor (20) and the charge air cooler ( 23) belong to an intake tract (6) of the diesel engine (2) and a three-way catalytic converter (15) is arranged in an exhaust tract (7) of the diesel engine (2), characterized in that exhaust gas from the Exhaust tract (7) can be removed upstream of the three-way catalytic converter (15) and can be introduced into the intake tract (6) by means of a first exhaust gas recirculation line (28) before the charge air cooler (23) and by means of a second exhaust gas recirculation line (29) after the charge air cooler (23) is, the first exhaust gas recirculation line (28,29) having an exhaust gas aftertreatment device (33) and the second exhaust gas recirculation line (29) upstream of the exhaust gas aftertreatment device (33) from the first exhaust asreturn line (28) branches off. Drive unit according to Claim 1 , characterized in that the three-way catalytic converter (15) is integrated in an exhaust gas particle filter (16). Drive unit according to Claim 2 , characterized in that the three-way catalytic converter (15) is generated by means of a coating of the exhaust gas particle filter (16). Drive unit according to Claim 2 or 3 , characterized in that the three-way exhaust gas catalytic converter (15) and / or the exhaust gas particle filter (16) with a further exhaust gas aftertreatment device (13), in particular an exhaust gas oxidation catalytic converter (14), is integrated in a common housing. Drive unit according to one of the preceding claims, characterized in that the three-way catalytic converter (15) is assigned a lambda probe. Drive unit according to Claim 5 , characterized in that the diesel internal combustion engine (2) can be operated by means of the lambda probe with a lambda value in a range from 0.9 to 1.1, in particular 0.97 to 1.03. Drive unit according to one of the preceding claims, characterized in that in the first exhaust gas recirculation line (28) and / or the second exhaust gas recirculation line (29) an exhaust gas control valve (31, 32) is provided. Drive unit according to one of the preceding claims, characterized in that at least one supply air throttle valve (24), in particular a three-way valve, is provided in the intake tract (6). Drive unit according to Claim 8 , characterized in that the first exhaust gas recirculation line (28) opens into the intake tract (6) before the supply air throttle valve (24) and / or the second exhaust gas recirculation line (29) after the supply air throttle valve (24). Drive unit according to one of the preceding claims, characterized in that a heat exchanger (37) is provided in the first exhaust gas recirculation line (28) and / or the second exhaust gas recirculation line (29). Method for operating a drive unit (1), in particular according to one or more of the preceding claims, wherein the drive unit (1) is a diesel internal combustion engine (2), an exhaust gas turbocharger (12), a charge air cooler (12) downstream of a compressor (20) of the exhaust gas turbocharger (12). 23) and an exhaust gas recirculation (27), the compressor (20) and the charge air cooler (23) belonging to an intake tract (6) of the diesel internal combustion engine (2) and in an exhaust tract (7) of the diesel internal combustion engine (2) a three-way Exhaust gas catalytic converter (15) is arranged, characterized in that exhaust gas is removed from the exhaust gas tract (7) by means of exhaust gas recirculation (27) and by means of a first exhaust gas recirculation line (28) before the charge air cooler (23) and by means of a second exhaust gas recirculation line (29) after the charge air cooler (23) can be introduced into the intake tract (6), the first exhaust gas recirculation line (28, 29) having an exhaust gas aftertreatment device (33) and the second Exhaust gas recirculation line (29) branches off from the first exhaust gas recirculation line (28) upstream of the exhaust gas aftertreatment device (33).

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