AT511548A1 - INTERNAL COMBUSTION ENGINE WITH AT LEAST ONE CATALYST UNIT - Google Patents

Abstract

The invention relates to an internal combustion engine with at least one catalyst unit (1) for cleaning the exhaust gases produced during operation of an internal combustion engine comprising at least one catalyst body (2) which is arranged upstream of an exhaust gas heat exchanger (4) in an exhaust gas flow path, in particular an exhaust gas recirculation line (6). wherein at least two or more catalyst bodies (2) which can be flowed through in parallel are arranged packed tightly over the cross-section.

Description

1 • · • · 56193

The invention relates to an internal combustion engine having at least one catalyst unit for cleaning the exhaust gases produced during operation of an internal combustion engine comprising at least one catalyst body, which is arranged upstream of an exhaust gas heat exchanger in an exhaust gas flow path, in particular an exhaust gas recirculation line.

The engine industry is under great pressure to produce engines with particularly low emissions. In order to reduce the emissions into the environment, for the internal combustion engines, especially for large engines, preferably for large diesel engines, an off-engine treatment and purification of exhaust gases to comply with legal requirements is required. The off-engine cleaning of the exhaust gases is usually carried out by means of a single catalyst unit. The exiting from the large engines exhaust gases are usually cleaned in an exhaust gas recirculation device, which is connected downstream of the large engine, and then fed to the large engine in part again. The exhaust gases are purified within the exhaust gas recirculation device of a catalyst unit and then added to an exhaust gas heat exchanger, in particular an exhaust gas cooler. In conventional exhaust gas coolers, soot build-up takes place on the cooled inner walls of the exhaust gas cooler. In order to reduce the hydrocarbons that react with the soot particles and deposit in the cooled inner walls of the exhaust gas cooler in the form of a sticky layer, usually arranged in a catalyst unit oxidation catalyst is connected upstream of the exhaust gas cooler.

From WO 2005/028 848 Al an exhaust gas heat exchanger, in particular an exhaust gas cooler for exhaust gas recirculation in motor vehicles with a single diesel oxidation catalyst, which is arranged in the inlet connection of the exhaust gas heat exchanger known. The substrate of this diesel oxidation catalyst fills the entire cross-section of the inlet nozzle of the exhaust gas heat exchanger. Thus, a great deal of substrate is needed to fill in the entire cross-section of the inlet nozzle. Furthermore, due to the design, no homogenous flow profile is created by the diffuser shape of the inlet nozzle, so that the edge regions of the diffuser can hardly be flowed through. Furthermore, the diesel oxidation catalyst causes a large flow resistance due to the design. This concept is therefore in particular with regard to the following: • Φ • Φ • · 2 φ • · Φ · φφφ · φ · ΦΦ # Φφ φφ φ · φφ #

Attaching the diesel oxidation catalyst in the inlet connection of the exhaust gas heat exchanger in large numbers unfavorable and thus poorly suited.

Conventional oxidation catalysts require a certain volume, which depends on the size of the engine to efficiently convert the oxidation. This volume of the oxidation catalyst is usually achieved over a large length and over a small cross-section, since a larger cross-sectional area of the oxidation catalyst due to manufacturing, installation conditions and other Bauaßgegebenheiten is not possible. Usually, the length is achieved either by a long catalyst body with a small cross section or by a plurality of catalysts arranged in series behind one another along the longitudinal axis of the catalyst system, which catalysts are known from catalyst technology. This leads to a greater pressure loss between the inlet and outlet of the catalyst unit. Furthermore, the plurality of catalysts arranged in series behind the longitudinal axis are realized by structurally complex and elaborately designed solutions.

Based on this prior art, the present invention seeks to provide an internal combustion engine with at least one catalyst unit for cleaning the resulting during operation of the internal combustion engine exhaust gases, wherein the pressure loss between the inlet and outlet of the catalyst unit is reduced and thus the influence on the Engine power is lower. Furthermore, the catalyst unit should be easy to install. In addition, an optimized flow through the catalyst unit should be given.

This object is achieved in that at least two or more parallel durchströmbare catalyst body are arranged densest packed over the cross section.

With regard to the design of the catalyst unit and its positioning, the internal combustion engine according to the invention has considerable advantages over the prior art. Thus, for example, by the inventive design of the catalyst unit of the internal combustion engine with two or more parallel durchström ble catalyst body, which are packed densest packed over the cross section, a lesser Druckveriust between the catalyst inlet and the catalyst outlet and a smaller impact on the 3 ··· ♦

Motor performance achieved. These advantages result from the shortening of the length of the catalyst unit and the extension of its cross section. Thus, the catalyst unit of the internal combustion engine according to the invention has a very advantageous compact design. In addition, the weight of the catalyst unit according to the invention is reduced.

An essential advantage of the internal combustion engine according to the invention with at least one catalyst unit is that the previously complex to be attached catalyst body in the catalyst unit by the inventive design is easily integrated into the catalyst unit. Another advantage of the subject invention is to provide a substantially homogeneous airfoil. By the most uniform flow through the cross section of the catalyst unit, a good efficiency is achieved.

In an advantageous embodiment of the internal combustion engine according to the invention with at least one catalyst unit is at least one, preferably all catalyst body, in particular as an oxidation catalyst, preferably formed as a diesel oxidation catalyst.

In a further advantageous embodiment of the internal combustion engine according to the invention, the catalyst bodies are arranged substantially free of forces in the exhaust gas flow path. Since the catalyst bodies are arranged substantially free of forces in the catalyst unit, no great demands are placed on the attachment of the catalyst body. Another advantage of this arrangement is that no thermal stress induction occurs due to the force-free arrangement. Under force-free here is a stress-free installation of the catalyst body, for example by positive locking - without welding or screw connection - to understand. The catalyst body can be inserted without tension, for example, in the exhaust gas flow path.

In a preferred embodiment of the internal combustion engine, at least one group, preferably all catalyst bodies, starts from a single plane. Thus, the length of the catalyst unit is shortened. This leads to a lower pressure loss and a smaller impact on engine performance. • * • • • • • * * * * * * * * * »· · · ··························································· I

In a further embodiment of the internal combustion engine, the catalyst bodies are arranged in the catalyst unit in at least one row. Thus, the length of the catalyst unit is shortened. This has the advantage that the weight is kept low.

In a particularly advantageous embodiment of the invention, the catalyst bodies have longitudinal axes, wherein the longitudinal axes of the catalyst bodies of a first and each further row form mutually substantially parallel planes. This results in a densest packing of the catalyst bodies in the catalyst unit over the cross section. This arrangement ensures that the pressure loss between the catalyst inlet and the catalyst outlet is lower. This compact embodiment of the invention allows even under very difficult conditions, such as those caused by vibrations, especially in the vehicle, not to destroy the catalyst body, or not to impair their function.

In a further embodiment of the invention, the cross section of the catalyst unit in the form of a polygon. Alternatively, the cross-section of the catalyst unit may have substantially the shape of a rectangle. It is also conceivable to design the cross section of the catalyst unit essentially in the form of a triangle. These arrangements ensure that the actively flowed surface of the structural conditions is optimally adapted. In these embodiments, a housing for the catalyst unit is saved, so that the construction can be made much easier.

For example, it has proven particularly useful to design the cross section of the catalyst unit with a rotationally symmetrical shape, in particular with a circular cross-sectional shape. In this case, the cross section of the catalyst body may have the shape of an ellipse, a rectangle or a circular shape. Thus, the space can be better utilized.

In another embodiment of the invention, the catalyst bodies are arranged in the exhaust gas flow path in a catalyst housing substantially free of force. As a result, no great demands are placed on the attachment of the catalyst bodies in the catalyst housing. The configuration of the 5 •··· 5 •···················································································

Invention with a catalyst housing has the advantage that the catalyst unit is thus easy to apply as a finished module.

In a further advantageous embodiment of the internal combustion engine according to the invention with at least one catalyst unit, the cross section of the catalyst housing in the form of a polygon. This has the advantage that a large number of catalyst bodies can be arranged in the catalyst housing, so that a compact construction is possible. As an alternative to this embodiment, the cross section of the catalyst housing may have substantially the shape of a rectangle or triangle. Furthermore, it is possible to design the cross-section of the catalyst housing substantially with a rotationally symmetrical shape, in particular a circular shape, or as an ellipse. In this way, the cross section of the catalyst housing is adapted to the structural conditions.

According to a further embodiment of the internal combustion engine according to the invention with at least one Kataiysatoreinheit touch the catalyst body substantially tangentially. This arrangement ensures compactness and better space utilization.

In another preferred embodiment of the invention, the plane of the longitudinal axes of the catalyst body forms an angle with the longitudinal axis of the exhaust gas heat exchanger. This allows a more compact and space-saving design.

In another preferred embodiment of the invention, the plane of the longitudinal axes of the catalyst body forms an angle with the longitudinal axis of the exhaust gas recirculation line. The advantage of this embodiment is that a compact design is ensured.

In a particularly preferred embodiment of the invention, a first angle between at least one longitudinal axis of the catalyst body and the longitudinal axis of the exhaust gas heat exchanger on the one hand, and / or a second angle between at least one longitudinal axis of the catalyst body and the longitudinal axis of the exhaust gas recirculation line on the other hand, about 90 °. This embodiment of the invention proves to be particularly advantageous, since a better adaptability is made possible. 6 »· 6» · * · m · • «• · • ··· • ·« «···

In a further particularly preferred embodiment, the catalyst unit is arranged in a deflection region of the exhaust gas flow path, wherein preferably the deflection region is designed as a 180 ° deflection. Thus, weight is saved and the space used optimally.

In another particularly preferred embodiment of the invention, the catalyst unit is partially disposed in the exhaust gas recirculation line and partly in the exhaust gas heat exchanger. A major advantage of this design is the very good space utilization. The installation space is shortened, the construction becomes lighter and more compact. As a result, a substantially homogeneous flow profile is provided. Due to the uniform flow of the cross section of the catalyst unit as possible, a good efficiency of the catalyst unit is achieved. In addition, a lower pressure drop between the catalyst inlet and the catalyst outlet and a smaller impact on the engine performance is achieved.

Alternatively to this embodiment, the catalyst unit can be arranged at least predominantly in the exhaust gas recirculation line or at least predominantly be arranged in the exhaust gas heat exchanger.

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.

The objects according to the invention will be explained in more detail below with reference to the exemplary embodiments and FIGS. 1 to 13a. Here are from the figures and their description further features and advantages of the invention. Showing:

Figure 1 is a schematic view of an exhaust aftertreatment device with a catalyst unit disposed in a catalyst housing. FIG. 2 a schematic representation of an exhaust aftertreatment device with a catalyst unit, in which at least three catalyst bodies through which flow is made in parallel;

FIG. 2a shows a schematic illustration of the exhaust gas aftertreatment device in a section according to the line IIa-IIa in FIG. 2; FIG. 7 • · • * ·· • · ♦ »• · * ·

Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 9a Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 13a Schematic representation of a circular cross-sectional shape of the catalyst body; schematic representation of a circular cross-sectional shape of the catalyst body; schematic representation of an oval cross-sectional shape of the catalyst body; schematic representation of a rectangular cross-sectional shape of the catalyst body; schematic representation of a cross section of the catalyst unit in the form of a polygon; schematic representation of a cross section of the catalyst unit in the form of a rectangle; schematic representation of a circular cross-sectional shape of the catalyst unit; schematic representation of a cross section of the catalyst unit having a shape of a star; schematic view of an exhaust aftertreatment device with a catalyst unit disposed in the exhaust gas recirculation line; schematic view of an exhaust aftertreatment device with a arranged in the exhaust heat exchanger inlet nozzle catalyst unit; schematic view of an exhaust aftertreatment device with a catalyst unit, wherein the angle between the longitudinal axis of the catalyst body and the longitudinal axis of the exhaust gas heat exchanger is 0 °; schematic view of an exhaust aftertreatment device with a catalyst unit, wherein the angle between the longitudinal axis of the catalyst body and the longitudinal axis of the exhaust gas heat exchanger 90 ° <a <180 °; schematic view of an exhaust aftertreatment device with a catalyst unit, wherein the Winkei between the longitudinal axis of the catalyst body and the longitudinal axis of the exhaust gas heat exchanger is 0 ° <a <90 °;

FIG. 1 schematically illustrates an exemplary embodiment of the exhaust aftertreatment device 10 according to the invention, not shown

Internal combustion engine, which is designed as a large diesel engine. The exhaust aftertreatment device 10 includes an exhaust gas recirculation line 6 and a catalyst unit 1 disposed upstream of an exhaust heat exchanger 4 with an exhaust heat exchanger inlet port 3. The direction of flow is indicated by the arrow EGR. In order to reduce the hydrocarbons formed with the soot particles on the cooled inner walls of the exhaust gas heat exchanger 4, which is formed as an exhaust gas cooler, a sticky layer, the catalyst unit 1 is arranged in front of the exhaust gas heat exchanger 4 expediently. The catalyst unit 1 is arranged in a catalyst housing 5 and has three catalyst bodies 2a, 2b and 2c, which are formed as diesel oxidation catalysts each having a volume Vi, V2, V3, a length L and a cross-sectional area A. The total volume V = Vi + V2 + V3 of the catalyst bodies 2a, 2b and 2c required for efficient oxidation is achieved in such a way that the cross-sectional area A is increased, the length L of the three catalyst bodies 2a, 2b and 2c flowing through in parallel in the catalyst unit 1 as short as possible due to the design. A shorter length of the catalyst bodies 2a, 2b and 2c causes a smaller pressure loss in the individual catalyst bodies 2a, 2b and 2c.

Hereinafter, the same reference numerals will be used for elements having equivalent functions.

2 shows an exemplary embodiment of the schematically illustrated exhaust gas aftertreatment device 10 according to the invention of an internal combustion engine (not shown) designed as a large diesel engine. The internal combustion engine comprises a catalytic converter unit 1 for purifying the exhaust gases produced during operation of an internal combustion engine which contains three catalytic converter bodies 2a, 2b, 2c Exhaust gas recirculation line 6 and an exhaust gas heat exchanger 4, wherein the exhaust gas heat exchanger 4 is formed as an exhaust gas cooler. The catalyst unit 1 is arranged upstream of the exhaust gas heat exchanger 4 in an exhaust gas flow path, in particular an exhaust gas recirculation line 6, wherein the three catalyst bodies 2 a, 2 b, 2 c flowed through in parallel are arranged in a densely packed manner over the cross section. The following is under tension free tension-free installation of the catalyst body, for example by positive engagement - without welding or screw connection - to understand. The flow direction of the exhaust gas is indicated by the arrow EGR. The catalyst bodies 2a, 2b, 2c are designed as diesel oxidation catalysts. Their end faces 9 are each arranged in a common plane 8 according to Figures 3 and 4. As shown in FIG. 2 a, the catalyst bodies 2 a, 2 b, 2 c touch tangentially and are welded gas-tight in the catalyst unit 1. They have a short length L, which allows a low pressure loss in the individual catalyst bodies 2a, 2b and 2c. The catalyst unit 1 is welded in a deflection region of the exhaust gas flow path, which is designed as a 180 ° deflection. It is partially in the exhaust gas recirculation line 6 and partially in the exhaust heat exchanger inlet nozzle 3, in particular in the catalyst receiving portion 3b, respectively. The exhaust gas recirculation line 6 and the exhaust gas heat exchanger 4 are expediently connected to one another via a flange 7 such that the exhaust gas recirculation line 6 is connected to the catalyst receiving section 3b of the exhaust gas heat exchanger inlet connection 3. The diffuser portion 3a of the exhaust heat exchanger inlet nozzle 3 is connected to the exhaust gas heat exchanger 4 by means of another flange. According to FIG. 2, the angles α and β are between at least one longitudinal axis 11 of the catalyst bodies 2a, 2b and 2c and the longitudinal axis 12 of the exhaust gas heat exchanger 1 or between at least one longitudinal axis 11 of the catalyst bodies 2a, 2b and 2c and the longitudinal axis 13 of the exhaust gas recirculation line 6 about 90 °.

The catalyst bodies 2a, 2b and 2c may have various structural forms. In addition to a circular cross-sectional shape, as shown in FIGS. 3 and 4 recognizable, is also an oval shape, as shown in Fig. 5, or a rectangular shape, which can be seen from Fig. 6, possible.

FIGS. 7 to 9 show different possible arrangements of the catalyst bodies 2 in the catalyst unit 1. The catalyst bodies 2 have longitudinal axes 11, wherein the longitudinal axes 11 of the catalyst bodies 2 form a first and each further row mutually parallel planes. FIG. 7 shows the catalyst unit 1 with a cross section in the form of a polygon. FIG. 8 shows a catalyst unit 1 with a cross section in the form of a rectangle. FIG. 9 shows a catalyst unit 1 with a circular cross section. From Fig. 9a is a star shape of the catalyst unit 1 can be seen. 10

* · 4 Φ • 4 · • * 4 44 4 4 I ·· 4 4 444 4 φ 4 4 44 4 • 4 4 4 44 * 4

In Ffg. 10 is a further embodiment of a schematically illustrated exhaust gas aftertreatment device 10 according to the invention of an internal combustion engine, not shown, which is designed as a large diesel engine. In the exhaust gas flow path, a catalyst unit 1, which contains three catalyst bodies 2a, 2b, 2c, an exhaust gas recirculation line 6 and an exhaust gas heat exchanger 4 not shown here, wherein the exhaust gas heat exchanger 4 is formed as an exhaust gas cooler arranged. The catalyst unit 1 is arranged upstream in the exhaust gas flow path completely in an exhaust gas recirculation line 6, wherein the three parallel-flowed catalyst body 2a, 2b, 2c are arranged densely packed force-free over the cross section. The catalyst bodies 2a, 2b, 2c are designed as diesel oxidation catalysts. As shown in FIGS. 3 and 4, the end faces 9 of the catalyst bodies 2 a, 2 b, 2 c are each arranged in a common plane 8. The catalyst bodies 2a, 2b, 2c touch tangentially and are gas-tight welded in the catalyst unit 1. In order to ensure a low pressure loss in the individual catalyst bodies 2a, 2b and 2c, the catalyst bodies 2a, 2b, 2c have a short length L.

FIG. 11 shows a further exemplary embodiment of a schematically illustrated exhaust gas aftertreatment device 10 according to the invention of an internal combustion engine, not shown, which is designed as a large diesel engine. The internal combustion engine has a catalyst unit 1, which contains three catalyst bodies 2a, 2b, 2c, and an exhaust gas recirculation line 6 and an exhaust gas heat exchanger 4, not shown here, wherein the exhaust gas heat exchanger 4 is formed as an exhaust gas cooler. The catalyst unit 1 is disposed upstream of the exhaust gas recirculation line 6 in an exhaust gas flow path, particularly in the exhaust gas heat exchanger inlet port 3 in the catalyst accommodating portion 3b. The three catalyst bodies 2a, 2b, 2c, which are flowed through in parallel, are designed as diesel oxidation catalysts and are arranged in a force-free manner over the cross-section packed in the most densely packed manner. Their end faces 9 are each arranged in a common plane 8, as shown in Figs. 3 and 4, respectively. The catalyst bodies 2a, 2b, 2c touch tangentially and are gas-tight welded in the catalyst unit 1. They have a short length L. This results in a low pressure loss in the individual catalyst bodies 2a, 2b and 2c. :: ιι • ♦ ··

According to a further exemplary embodiment, which is shown in FIG. 12, a schematically illustrated exhaust gas aftertreatment device 10 according to the invention of an internal combustion engine, not shown, which is designed as a large diesel engine is shown. The internal combustion engine has a catalyst unit 1, which contains three catalyst bodies 2a, 2b, 2c, and an exhaust gas recirculation line 6 and an exhaust gas heat exchanger 4, wherein the exhaust gas heat exchanger 4 is ausgeblldet as exhaust gas cooler. The catalyst unit 1 is located upstream of the exhaust gas recirculation line 6, in an exhaust gas flow path, particularly in the exhaust gas heat exchanger inlet port 3 in its catalyst receiving section 3b. The exhaust gas recirculation line 6 and the exhaust gas heat exchanger inlet connection 3 are expediently connected to one another via a flange 7 such that the exhaust gas recirculation line 6 is connected to the catalyst receiving section 3b of the exhaust gas heat exchanger inlet connection 3. The diffuser portion 3 a of the exhaust heat exchanger inlet nozzle 3 is connected to the exhaust gas heat exchanger 4. The angle α between at least one longitudinal axis 11 of the catalyst body 2a, 2b and 2c and the longitudinal axis 12 of the exhaust gas heat exchanger 1 is about 0 °. The direction of flow is indicated by the arrow EGR. The catalyst bodies 2a, 2b, 2c are designed as diesel oxidation catalysts and arranged densely packed over the cross-section without forces. Their end faces 9 are each arranged in a common plane 8, as shown in Figures 3 and 4. The catalyst bodies 2a, 2b, 2c touch tangentially and are gas-tight welded in the catalyst unit 1.

In the embodiment according to FIG. 13 a, an exhaust gas aftertreatment device 10 according to the invention of an internal combustion engine, not shown, which is designed as a large diesel engine, is shown schematically. The internal combustion engine has a catalytic converter unit 1 for purifying the exhaust gases produced during operation of an internal combustion engine, which contains three catalytic converter bodies 2a, 2b, 2c, and an exhaust gas recirculation line 6 and an exhaust gas heat exchanger 4. The catalytic converter unit 1 is upstream of the exhaust gas heat exchanger 4, which is designed as an exhaust gas cooler is arranged in an exhaust gas flow path, in particular an exhaust gas recirculation line 6, wherein the three parallel flowed through the catalyst body 2 a, 2 b, 2 c over the cross-section densest packed forces are arranged. The catalyst unit 1 is partially disposed in the exhaust gas recirculation line 6 and partly in the exhaust gas heat exchanger inlet port 3 in its catalyst receiving section 3b. The flow direction is through the

Arrow EGR indicated. The catalyst unit 1 is welded in a deflection region of the exhaust gas flow path. The exhaust gas recirculation line 6 and the exhaust gas heat exchanger 4 are expediently connected to one another via a flange 7 such that the exhaust gas recirculation line 6 is connected to the catalyst receiving section 3b of the exhaust gas heat exchanger inlet connection 3. The angle α between at least one longitudinal axis 11 of the catalyst bodies 2a, 2b and 2c, which are designed as diesel oxidation catalysts, and the longitudinal axis 12 of the exhaust gas heat exchanger 4 is less than about 90 °, in particular less than about 60 °. The size of the angle a is selected depending on the installation conditions.

In another embodiment of the inventive schematically shown exhaust aftertreatment device 10 of an internal combustion engine, not shown, which is designed as a large diesel engine, as shown in FIG. 13, the angle α between at least one longitudinal axis 11 of the catalyst body 2a, 2b and 2c, which are designed as diesel oxidation catalysts, and the Longitudinal axis 12 of the exhaust gas heat exchanger 4 is greater than about 90 °, preferably 90 ° <a <180 °, in particular greater than about 120 °.

The invention is not limited to the embodiments described above, but rather transferable to other internal combustion engines. It is also possible to combine corresponding measures of the various embodiments with each other.

The invention is generally applicable to internal combustion engines. Catalyst body 3 Exhaust heat exchanger inlet nozzle 3a Diffuser section 3b Catalyst receiving section 4 Exhaust gas heat exchanger, in particular for exhaust gas recirculation 5 Catalyst housing 6 Exhaust gas recirculation line 7 Flange 8 Plane 9 End face 10 Exhaust gas aftertreatment device 11 Longitudinal axis of the catalyst body 12 of the longitudinal axis of the exhaust gas heat exchanger 13 of the longitudinal axis of the exhaust gas recirculation line a, ß angle V, Vi, Vz, V3 volume

L length of the catalyst body

Claims (18)

1. An internal combustion engine having at least one catalytic converter unit (1) for cleaning the exhaust gases produced during operation of an internal combustion engine, comprising at least a catalyst body (2), which is arranged upstream of an exhaust gas heat exchanger (4) in an exhaust gas flow path, in particular an exhaust gas recirculation line (6), characterized in that at least two or more parallel durchströmmbare catalyst body (2) are arranged densest packed over the cross section. 2. Internal combustion engine according to claim 1, characterized in that the catalyst body (2) are arranged substantially free of force in the exhaust gas flow path. 3. 'internal combustion engine according to claim 1 to 2, characterized in that the catalyst body (2) end faces (9), which are each arranged in a common plane (8). 4. Internal combustion engine according to one of the claims 1 to 3, characterized in that the catalyst body (2) in the catalyst unit (1) are arranged in at least one row. 5. Internal combustion engine according to claim 4, characterized in that the catalyst body (2) longitudinal axes (11), wherein the longitudinal axes (11) of the catalyst body (2) form a first and each further row to each other substantially parallel planes. 6. Internal combustion engine according to claim 1 to 5, characterized in that the cross section of the catalyst unit (1) has the shape of a polygon. 7. Internal combustion engine according to claim 6, characterized in that the cross section of the catalyst unit (1) has substantially the shape of a rectangle. • * # 15 «*« «* # • · · · · · ···· ··· 8. Internal combustion engine according to claim 6, characterized in that the cross section of the catalyst unit (1) has substantially the shape of a triangle. 9. Internal combustion engine according to claim 1 to 5, characterized in that the cross section of the catalyst unit (1) has a rotationally symmetrical shape. 10. Internal combustion engine according to one of the preceding claims, characterized in that the Kataiysatorkörper (2) are arranged in a catalyst housing (5). 11. Internal combustion engine according to one of the preceding claims, characterized in that the catalyst body (2) touch substantially tangentially. 12. Internal combustion engine according to one of the preceding claims, characterized in that the plane of the longitudinal axes (11) of the catalyst body (2) forms an angle (a) with the longitudinal axis (12) of the exhaust gas heat exchanger (4). 13. Internal combustion engine according to claim 1 to 11, characterized in that the plane of the longitudinal axes (11) of the catalyst body (2) forms an angle (ß) with the longitudinal axis (13) of the exhaust gas recirculation line (6). 14. Internal combustion engine according to claim 12 and 13, characterized in that the angle (a) between at least one longitudinal axis (11) of the catalyst body (2) and the longitudinal axis (12) of the exhaust gas heat exchanger (4) and / or the angle (ß) between at least one longitudinal axis (11) of the catalyst body (2) and the longitudinal axis (13) of the exhaust gas recirculation line (6) is about 90 °. 15. Internal combustion engine according to one of the preceding claims, characterized in that the catalyst unit (1) is arranged in a deflection region of the exhaust gas flow path, wherein preferably the deflection region is designed as a 180 ° deflection. 16. Internal combustion engine according to one of the preceding claims, characterized in that the catalyst unit (1) partially in the exhaust gas recirculation line (6) and partially in the exhaust gas heat exchanger inlet nozzle (3) is arranged. 17. Internal combustion engine according to claim 16, characterized in that the exhaust gas heat exchanger inlet nozzle (3) has a diffuser portion (3a) and a catalyst receiving portion (3b). 18. Internal combustion engine according to claim 1 to 17, characterized in that the catalyst unit (1) is arranged at least predominantly in the exhaust gas recirculation line (6). 19. Internal combustion engine according to claim 1 to 17, characterized in that the catalyst unit (1) is arranged at least predominantly in the exhaust gas heat exchanger (4). 2011 06 06 Ko / Fu