WO2015090520A1 - Charged internal combustion engine - Google Patents

Abstract

The present invention relates to a charged internal combustion engine (1), in particular for a utility vehicle, comprising an engine block (2) which contains a plurality of cylinders (3), a fresh air system (5) for supplying fresh air to the cylinders (3), an exhaust gas system (6) for removing exhaust gas from the cylinders (3), an exhaust gas recirculation system (7) for recirculating exhaust gas from the exhaust gas system (6) to the fresh air system (5), an exhaust gas turbocharger (8), the turbine (9) of which is arranged in the exhaust gas system (6) and the compressor (10) of which is arranged in the fresh air system (5), wherein a removable point (11) of the exhaust gas recirculation system (7) is arranged on the exhaust gas system (6) upstream of the turbine (9), while an introductory point (12) of the exhaust gas recirculation system (7) is arranged on the fresh air system (5) downstream of the compressor (10). An improved equal distribution of the recirculated exhaust gas between the individual cylinders arises if the introductory point (12) has an admixing device (25) which, via at least two admixing openings (27) spaced apart from one another in a longitudinal direction (29) of the mixing section (28), introduces recirculated exhaust gas into a mixing section (28) of the fresh air system (5).

Description

 Charged internal combustion engine

The present invention relates to a supercharged internal combustion engine, the

is particularly suitable for a commercial vehicle.

An internal combustion engine conventionally includes an engine block including a plurality of cylinders, a fresh air system for supplying fresh air to the cylinders, and an exhaust system for exhausting exhaust from the cylinders. modern

Internal combustion engine are also equipped with an exhaust gas recirculation system, with the aid of which exhaust gas can be returned from the exhaust system to the fresh air system. Exhaust gas recirculation, in particular an external, ie outside the engine block, exhaust gas recirculation can be used to reduce the pollutant emissions and to improve the energy efficiency of the internal combustion engine.

A supercharged internal combustion engine is operated at an elevated pressure level. For this purpose, it is equipped for example with an exhaust gas turbocharger whose turbine is arranged in the exhaust system and its compressor in the fresh air system

is arranged. In a high-pressure side exhaust gas recirculation, a removal point of the exhaust gas recirculation system upstream of the turbine is arranged on the exhaust system, while a discharge point of the exhaust gas recirculation system downstream of the compressor at the

Fresh air system is arranged.

Thus, the recirculated exhaust gas can flow from the exhaust system to the fresh air system, a corresponding pressure gradient is required. Such a thing

Pressure gradient may arise during normal operation of the engine during so-called intake strokes of pistons moving in the cylinders of the engine block. As a result, the recirculated exhaust gas is sucked intermittently or in pulses and introduced into the fresh air system. While the intake strokes of the pistons within the fresh air system generate negative pressure pulses, the exhaust from the

Exhaust gas recirculation system can suck in addition or alternatively, following an expansion stroke or -hub Ausschiebehübe the piston on the exhaust side pressure pulses generate, which drive the exhaust gas into the exhaust gas recirculation system.

Inadequate mixing between the recirculated exhaust gas and the fresh air also results in the combustion chambers of the cylinder uneven distribution of the mixture of fresh air and recirculated exhaust gas, which jeopardizes the desired objectives, namely pollutant reduction and efficiency improvement.

From DE 10 2006 035 183 A1 a mixing device is generally known, with the aid of which recirculated exhaust gas can be supplied to a fresh air system. The admixing device has a plurality of admixing openings, through which the recirculated exhaust gas is introduced into a mixing section of the fresh air system. In this case, the admixing openings are spaced apart in a longitudinal direction of the mixing section. This ensures that the intermittently sucked or expelled exhaust gases are introduced via a comparatively large longitudinal section of the fresh air system, namely via the mixing section, whereby the mixing with the fresh air improves. As a consequence, the exhaust gas recirculation rate in the individual combustion chambers can also be homogenized.

The present invention addresses the problem of providing a boosted internal combustion engine with high-pressure side exhaust gas recirculation an improved or at least another embodiment, which is characterized by an improved uniform distribution of the recirculated exhaust gases to the individual cylinders.

This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea, the discharge point of the

high pressure side exhaust gas recirculation system equipped with a Zumischeinrichtung or to realize by a Zumischeinrichtung, the admixing device via at least two Zumischöffnungen recirculated exhaust gas into a mixing section of the fresh air system initiates, it being provided that the at least two

Admixing openings in a longitudinal direction of the mixing section are spaced from each other. By this construction, the pulse-like introduction of the recirculated takes place Exhaust gas over at least two spaced apart in the flow direction of the fresh air Zumischöffnungen, whereby the mixing of the recirculated exhaust gas is improved with the fresh air flow. Overall, this makes it possible to improve the uniform distribution of a mixture of recirculated exhaust gas and fresh air in the individual combustion chambers of the engine block.

According to an advantageous embodiment, the fresh air system a

Have fresh air manifold, the one inlet opening and a cylinder for each

Has outlet opening. Since the fresh air distributor has only a single inlet opening and a plurality of outlet openings, at least one outlet opening is arranged proximal to the inlet opening, while at least one other outlet opening is arranged distally of the inlet opening. This results within the fresh air manifold different lengths of flow paths from the inlet opening to the different outlet openings. In order to counteract this, the fresh air distributor has, in the region of the inlet opening, a dividing wall which has a direct flow path from the inlet opening to at least one proximal to the inlet opening

Outlet opening obstructed. As a result, the flow path from the inlet opening to this at least one proximal outlet opening is forcibly extended, as a result of which, overall, the flow paths from the inlet opening to the various outlet openings are aligned with respect to their length. This measure leads to improved mixing of the recirculated exhaust gas with the transported in the fresh air system gas, which is preferably fresh air or a fresh air-fuel mixture. An improved mixing in this way also contributes to the homogenization of the exhaust gas recirculation rate within the individual

Combustion chambers at.

In another embodiment, the cylinder of the engine block in two

Cylinder groups be divided. For example, the cylinders may be arranged for this purpose in two different cylinder banks of the engine block, for example in a V-type engine. In an inline engine, the two cylinder groups are then

expediently arranged one behind the other. If two cylinder groups are provided, the exhaust system may be equipped with two separate exhaust manifolds or with a split exhaust manifold having two header sections. The two exhaust manifolds or the two collector sections are then expediently assigned to separate high-pressure regions of the exhaust system in order to separate the exhaust gases of the two

Cylinder groups separately to be able to supply two separate turbines or preferably a common turbine. Preferred is an embodiment in which a double-flow Turbine is used, wherein the separate exhaust gas streams are supplied separately to the two floods of the turbine, such that each exhaust gas flow leads to exactly one exhaust gas flow. Accordingly, the two high pressure areas of the exhaust system are connected to one of the two turbine floods. The two cylinder groups are expediently chosen such that pressure pulses in the exhaust gas within the respective cylinder group are as synchronized as possible, while the pressure pulses of one cylinder group occur asynchronously with the pressure pulses of the other cylinder group. As a result, disruptive interactions within the exhaust gas streams can be reduced.

According to an advantageous development, both turbine flows can each be controlled via a separate wastegate. A wastegate is a controlled bypass for bypassing a turbine wheel of the respective turbine. By opening the bypass or the wastegate, the pressure difference between an inlet side and an outlet side of the turbine wheel decreases, whereby the drive power of the turbine wheel is reduced accordingly. Thus, the wastegate ultimately serves to control the power of the turbine and thus of the exhaust gas turbocharger. By means of the separate waste gates assigned to the two turbine flows, the pressures in the two separate high-pressure regions can thus be separated and controlled independently of one another.

In another advantageous development, the sampling point of

Exhaust gas recirculation system must be connected to the exhaust system so that it is assigned to only one cylinder group. For example, the removal point is arranged on one of the two exhaust manifolds or on one of the two collector sections. Likewise, the removal point between the respective exhaust manifold and the turbine can be connected to one of the two high pressure areas of the exhaust system. Through this

Measure is achieved that only in the one high-pressure area and thus only in the one turbine flood, a pressure drop due to the exhaust gas recirculation takes place, so that the high pressure of the other high pressure area or the other turbine flood

Power generation in the turbine can be used. Unless the two

Turbine floods within the turbine are assigned to two different power levels anyway, the removal of the exhaust gas to be recirculated expediently takes place in a region associated with the weaker turbine flow, so that over the

more powerful turbine flood still the full power can be generated.

In principle, the internal combustion engine presented here can be operated in a conventional manner with a liquid fuel which is expediently injected directly into the combustion chambers of the cylinders. Alternatively, however, is an embodiment of the Internal combustion engine as a gas engine possible, in which the fuel gaseous reaches the combustion chambers. According to an advantageous embodiment, the internal combustion engine can be equipped with a fuel mixing device, via which the gaseous fuel is introduced upstream of the engine block in the fresh air system. In this case, therefore, no introduction of the fuel takes place directly in the combustion chambers of the cylinder. The fuel mixing device is expedient downstream of the

Compressor and upstream of the discharge point of the exhaust gas recirculation system to the

Fresh air system connected. In this way, at first an intensive

Mixing of the gaseous fuel reaches the supplied via the fresh air system compressed fresh air, so that the recirculated exhaust gas is then introduced into a mixture of fresh air and fuel.

In another advantageous embodiment, the admixing device of the exhaust gas recirculation system can have exactly two admixing openings which are spaced so far apart in the longitudinal direction of the mixing section that an admixing volume of the metering chamber measured from one admixing opening to the other admixing opening

Mixing section corresponds approximately to an effective cylinder volume of one of the cylinders. Suitably, all cylinders of the engine block have the same effective cylinder volume. The admixing volume thus substantially corresponds to the respective effective cylinder volume of a cylinder, wherein the term "about" or the formulation "substantially" should include deviations between the admixing volume and the effective cylinder volume of ± 10% and preferably ± 5%. The effective cylinder volume usually corresponds to about 90% of the actual geometric cylinder volume.

In an alternative embodiment, the admixing of the

Exhaust gas recirculation system have more than two Zumischöffnungen, wherein one of the transported in the fresh air system gas or gas mixture first flowed first Zumischöffnung and one of said gas or gas mixture last flowed last admixing opening are furthest from each other. In this case, the first admixing opening and the last admixing opening are spaced so far apart in the longitudinal direction of the mixing section that an admixing volume of the mixing section measured from the first admixing opening to the last admixing opening corresponds approximately to an effective cylinder volume of one of the cylinders. Also in this case, dimensional deviations between the admixing volume and the effective cylinder volume of not more than 10%, preferably of not more than 5%, are tolerated. By dimensioning the admixing volume in such a way that it corresponds approximately to an effective cylinder volume, it is achieved that maximally the admixing volume is sucked in with each intake stroke, so that therefore always a mixture of the

recirculated exhaust gas and the transported via the fresh air line gas or

Gas mixture is sucked.

According to a particularly advantageous development, the admixing device can have an inlet for recirculating exhaust gas, which is in the region of the first

Zumischöffnung or with respect to the flow direction in the fresh air system upstream of the first admixing opening is arranged. Thus, the recirculated exhaust gas in the region of the admixing device has substantially the same flow direction as the gas or gas mixture transported in the fresh air system.

In another advantageous embodiment, the mixing section of the

Fresh air system be configured as a straight pipe, which is the achievement of a homogeneous mixing between recycled exhaust gas and the gas or

Gas mixture of the fresh air system favors. Additionally or alternatively, the

Zumischeinrichtung have a pipe section having an inlet for

Having recirculated exhaust gas and the via the admixing to the

Mixing section is connected. In particular, in conjunction with a configured as a straight pipe mixing section results from this design a compact design for the discharge point.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically, 1 is a greatly simplified schematic diagram of a supercharged internal combustion engine,

Fig. 2 is a simplified representation of the internal combustion engine in the region of

 Discharge point of an exhaust gas recirculation system,

3 is a view as in Fig. 2, but in another embodiment,

4 is an isometric view of the internal combustion engine in the region of

 Einleitstelle, in another embodiment.

According to FIG. 1, an internal combustion engine 1 preferably comprises one

Commercial vehicle is arranged, an engine block 2, which contains a plurality of cylinders 3, each enclosing a combustion chamber 4. The internal combustion engine 1 is further equipped with a fresh air system 5 for supplying fresh air to the cylinders 3 and with an exhaust system 6 for discharging exhaust gas from the cylinders 3. Furthermore, an exhaust gas recirculation system 7 is provided, with the aid of which exhaust gas from the exhaust system

6 to the fresh air system 5 can be returned. The internal combustion engine 1 is charged, for which purpose it is equipped with an exhaust gas turbocharger 8, the turbine 9 is arranged in the exhaust system 6 and the compressor 10 is arranged in the fresh air system 5. The exhaust gas recirculation system 7 has a removal point 11 for

Removing rückzuführendem exhaust gas from the exhaust system 6, which is arranged upstream of the turbine 9 to the exhaust system 6. Furthermore, the exhaust gas recirculation system includes

7 a discharge point 12 for introducing the recirculated exhaust gas into the fresh air system 5, which is arranged downstream of the compressor 10 to the fresh air system 5.

Furthermore, the fresh air system 5 shown here comprises an air filter 13, which is arranged upstream of the compressor 10, a bypass 14 for bypassing the compressor 0, which is controllable by means of a bypass valve 15, a charge air cooler 16 and purely by way of example a controllable throttle 17 the fresh air system 5 is equipped with a fresh air manifold 8, which distributes the supplied fresh air to the individual cylinder 3.

The exhaust system 6 comprises at least one exhaust collector 19, which is the one of the

Cylinders 3 collecting exhaust gas and forwards, so that it passes to the turbine 9. Downstream of the turbine 9, the exhaust system 6 contains various exhaust gas purification devices, such as a pre-catalyst 20, a main catalyst 21 and a

Additional catalyst 22. The aforementioned exhaust gas purification devices are pure exemplified, and in particular for the case that the internal combustion engine 1 is designed as a gas engine, which is operated with a gaseous fuel. If liquid fuels are used, the exhaust system 6 may also have other exhaust gas purification devices, such as a particulate filter and an SCR system. Furthermore, the exhaust system 6 in the usual way at least one

Silencer included.

The exhaust gas recirculation system 7 may optionally be equipped with an exhaust gas recirculation cooler 23. Further, an exhaust gas recirculation valve 24 is provided to adjust the exhaust gas recirculation rate.

According to FIGS. 2 to 4, the point of introduction 12 of the exhaust gas recirculation system 7 can have an admixing device 25. The admixing device 25 forwards the recirculated exhaust gas 26 indicated in FIGS. 2 and 3 by an arrow

at least two admixing openings 27 in a mixing section 28 of the fresh air system 5 a. The at least two admixing openings 27 are spaced apart from one another in a longitudinal direction 29 of the mixing section 28 indicated in FIGS. 2 to 4 by a double arrow. In the embodiment shown in Figure 2 exactly two such admixing openings 27 are provided. In contrast, in the embodiment shown in FIGS. 3 and 4, more than two, in particular five, admixing openings 27 are provided, which are each spaced apart in the longitudinal direction 29. According to Figure 1, the fresh air manifold 18 has an inlet port 30 and each cylinder 3 an outlet 31. The fresh air manifold 18 extends along the engine block 2. The inlet port 30 is disposed laterally at a longitudinal end 32 of the fresh air manifold 18. In contrast, the outlet openings 31 are arranged laterally distributed over the entire length of the fresh air manifold. Accordingly, the distances of the outlet openings 31 from the inlet opening 30 vary. In the fresh air distributor 18, a dividing wall 33 is arranged, which in the example of FIG. 1 begins at the longitudinal end 32, on which the inlet opening 30 is also arranged. The partition 33 extends within the fresh air manifold 18 such that it provides a direct flow path from the inlet port 30 to at least one proximal to the inlet port 30

arranged outlet opening 31 obstructed. In the example of FIG. 1, the dividing wall 33 extends from the longitudinal end 32 shown on the left over three outlet openings 31, while leaving the remaining three outlet openings 31 uncovered. Thus, the direct flow paths to the three exhaust ports 31 shown on the left are obstructed by the partition wall 33. Overall, with the help of the partition wall 33 thus of θ the gas or gas mixture transported in the fresh air system 5 actually

flow paths are matched with respect to their length to each other.

The cylinders 3 of the engine block 2 are divided into two groups of cylinders 34 and 35, which is indicated in FIG. 1 by curly brackets. The exhaust manifold 19 is configured in the example as a divided exhaust manifold 19 having two collector sections 36 and 37. The one or first header section 36 collects the exhaust gases of one or the first cylinder group 34, while the other or second header section 37 collects the exhaust gases of the other or second cylinder group 34 and is sealed off from the first header section 36. The two header sections 36, 37 lead the collected exhaust gases separately to separate high-pressure areas 38, 39 of the exhaust system 6. The turbine 9 is designed here as a double-flow turbine, so that the turbine 9 accordingly contains two separate, here unspecified or not recognizable turbine floods. It is noteworthy that the two turbine flows can each be controlled via a separate wastegate 40 or 41. For simplified illustration, the two waste gates 40, 41 are symbolized by valves in Figure 1, in external

Bypass paths 42 and 43 are arranged, each one not shown here

Turbine wheel of turbine 9 bypass. However, the waste gates 40, 41 or the associated bypasses are preferably formed within the turbine 9.

The sampling point 1 1 of the exhaust gas recirculation system 7 is so to the exhaust system. 6

connected, that it is associated with only one of the two cylinder groups 34, 35. In the example, the removal point 1 1 of the second cylinder group 35 is assigned. In this case, the removal point 11 is arranged on the second collector section 37. The two unspecified turbine floods can be designed so that they can transmit different levels of power to the turbine 9. Appropriately, the

Exhaust gas recirculation system 7 connected to the exhaust system 6, that they the

recirculated exhaust gas ultimately deprives the weaker turbine tide.

In the preferred example shown here, the internal combustion engine 1 is designed as a gas engine. The gaseous fuel is introduced via a fuel mixing device 44 in the fresh air system 5. The fuel mixing device 44 thus connects a fuel supply system 45 with the fresh air system 5. The fuel mixing device 44 is downstream of the compressor 10 and upstream of the discharge point 12 of

Exhaust gas recirculation system 7 connected to the fresh air system 5. Accordingly, the fresh air system 5 conveys "normal" charge air to the compressor 10. From the compressor 10 to the fuel mixing device 44, the fresh air system 5 conveys compressed air Fresh air, which can also be referred to as charge air. Of the

Fuel mixing device 44 to the point of introduction 12 promotes the fresh air system 5, a mixture of charge air and fuel. From the point of introduction 12 to the cylinder 3, the fresh air system 5 then conveys a mixture of recirculated exhaust gas, charge air and

Fuel. In FIGS. 2 and 3, the admixed fuel is indicated by an arrow and designated by 46. Further, in Figures 2 and 3, the charged fresh air or charge air is indicated by an arrow 47.

In the embodiment shown in FIG. 2, the admixing device 25 has exactly two admixing openings, namely a first admixing opening 27 'and a second admixing opening 27'

The two admixing openings 27 ', 27 "are so far apart in the longitudinal direction 29 of the mixing section 28 that within the

Mixing section 28 of the one Zumischöffnung 27 'to the other Zumischöffnung 27 "Zumischvolumen 48 arises that substantially, ie with a maximum deviation of 10%, preferably with a maximum deviation of 5%, an effective cylinder volume of the cylinder 3 corresponds. The mixing section 28 is configured as a rectilinear pipe 50, wherein a longitudinal axis of this pipe 50 defines the longitudinal direction 29 of the mixing section 28. The admixing device 25 has a pipe section 49, which is likewise rectilinear here and extends parallel to the pipe 50 of the mixing section 28 In the example of Figure 2, the

Pipe section 49 at its longitudinal ends depending on a connecting pipe 51, the

Pipe section 49 fluidly connects each with one of the admixing openings 27. Exactly centrally between the longitudinal ends of the pipe section 49, an inlet opening 52 is arranged, via which the recirculated exhaust gas 26 enters the pipe section 49.

In the embodiment shown in FIG. 3, the mixing section 28 is again formed by a rectilinear pipe 50. The admixing device 25 also has a rectilinear pipe section 49, which in this case is connected directly to the pipe 50 of the mixing section 28. In particular, have the tube 50 of the

Mixing section 28 and the pipe section 49 of the admixing 25 a

common wall 53, wherein the admixing openings 27 are formed by openings of this common wall 53. As mentioned, more than two admixing openings 27 are provided in the embodiment shown in FIG. One of the mixture of charge air 47 and fuel 46 first flowed in admixing opening 27 is in

The following is referred to as the first admixing opening 27 ', while an admixing opening 27, which is farthest from it and has been flowed lastly by the said mixture, is shown in FIG

Will be referred to as the last admixing opening 27 ", also in the case of the embodiment shown in FIG In the embodiment shown, it is provided that the first admixing opening 27 'and the last admixing opening 27 "in the longitudinal direction 29 of the ischa section 28 define an admixing volume 48 in the mixing section 28 indicated by a curly bracket, which approximately corresponds to the effective cylinder volume of one of the cylinders 3.

In the embodiment shown in FIG. 3 too, the recirculated exhaust gas 26 is fed to the pipe section 49 of the admixing device 26 via an inlet opening 52, which can also be referred to as inlet 52. The inlet 52 or the inlet opening 52 is arranged according to FIG. 3 in the region of the first admixing opening 27 '. In FIG. 3, the inlet 52 is arranged upstream of the first admixing opening 27 'even with respect to the flow conducted in the fresh air system 5.

FIG. 4 shows a concrete embodiment of the admixing device 25 shown in FIG. 3. Recognizable is the exhaust gas recirculation system 7 in the area of the exhaust gas recirculation valve 24 and the introduction point 12. The mixing section 49 is visible from the admixing device 25 and connected to the tube 50 of the mixing section 28. is grown. Upstream of the mixing section 28, the fuel mixing device 44 is indicated. Downstream of the mixing section 28 via a curved pipe section 54 in the fresh air manifold 18 via.

Claims

claims 1. supercharged internal combustion engine, in particular for a commercial vehicle,  with an engine block (2) containing a plurality of cylinders (3),  - With a fresh air system (5) for supplying fresh air to the cylinders (3), with an exhaust system (6) for discharging exhaust gas from the cylinders (3), - With an exhaust gas recirculation system (7) for exhaust gas recirculation from the exhaust system (6) to the fresh air system (5),  - With an exhaust gas turbocharger (8), the turbine (9) in the exhaust system (6) is arranged and the compressor (10) in the fresh air system (5) is arranged,  - An extraction point (1 1) of the exhaust gas recirculation system (7) upstream of the turbine (9) is arranged on the exhaust system (6),  - An inlet point (12) of the exhaust gas recirculation system (7) downstream of the compressor (10) is arranged on the fresh air system (5),  - wherein the inlet point (12) has a mixing device (25), the at least two Zumischöffnungen (27) recirculated exhaust gas in a  Introducing mixing section (28) of the fresh air system (5),  - wherein the at least two admixing openings (27) in a longitudinal direction (29) of the mixing section (28) are spaced from each other, - wherein the admixing device (25) of the exhaust gas recirculation system (7) more than two admixing openings (27), wherein a first admixing opening (27 ') and a last admixing opening (27 ") are furthest from each other, - wherein the first admixing opening (27 ') and the last admixing opening (27 ") in the longitudinal direction (29) of the mixing section (28) are spaced so far apart that one of the first admixing opening (27') to the last admixing opening (27") ) measured Zumischvolumen (48) of the mixing section (28) corresponds approximately to an effective cylinder volume of the cylinder (3). 2. Internal combustion engine according to claim 1  characterized in that  the fresh air system (5) has a fresh air distributor (18) having a  Inlet opening (30) and each cylinder (3) has at least one outlet opening (31), wherein in the region of the inlet opening (30) has a partition wall (33) in  Fresh air manifold (18) is arranged, which obstructs a direct flow path from the inlet opening (30) to at least one proximal to the inlet opening (30) arranged outlet opening (31). 3. Internal combustion engine according to claim 1 or 2  characterized in that  - that the cylinders (3) are divided into two groups of cylinders (34, 35),  - That the exhaust system (6) has two separate exhaust manifold or a divided exhaust manifold (19) with two collector sections (36, 37), each of a cylinder group (34, 35) and separate high pressure areas (38, 39) of  Associated exhaust system (6),  - That the turbine (9) is designed as a double-flow turbine (9),  - That the two high pressure areas (38, 39) are connected to one of the two turbine floods. 4. Internal combustion engine according to claim 3,  characterized in that  both turbine flows are each controlled by a separate wastegate (40, 41). 5. Internal combustion engine according to claim 3 or 4,  characterized in that the removal point (11) is connected to the exhaust system (6), that it is associated with only one cylinder group (35). 6. Internal combustion engine according to one of claims 1 to 5,  characterized in that  the internal combustion engine (1) is configured as a gas engine whose gaseous fuel is introduced into the fresh air system (5) via a fuel mixing device (44), wherein the fuel mixing device (44) downstream of the compressor (10) and upstream of the discharge point (12) of the exhaust gas recirculation system ( 7) to the  Fresh air system (5) is connected. 7. Internal combustion engine according to claim 1,  characterized in that  the admixing device (25) has an inlet (52) for recirculating exhaust gas, which is arranged in the area of the first admixing opening (27 ') or with respect to a gas flow in the fresh air system (3) upstream of the first admixing opening (27'). 8. Internal combustion engine according to one of claims 1 to 7,  characterized in that  - That the mixing section (28) of the fresh air system (5) is designed as a rectilinear pipe (50), and / or  - That the admixing device (25) has a pipe section (49) having an inlet (52) for exhaust gas to be recirculated and over the  Zumischöffnungen (27) is connected to the mixing section (28).