EXHAUST GAS AFTERTREATMENT DEVICE AND EXHAUST GAS AFTERTREATMENT SYSTEM OF AN INTERNAL COMBUSTION ENGINE

Description

[0001] The invention relates to an exhaust gas aftertreatment system of an internal combustion engine according to the preamble of claim 1.

[0002] The present invention relates to the field of so-called large internal combustion engines, whose cylinders have piston diameters of at least 140 mm, in particular of at least 175 mm. Examples of such large internal combustion engines include marine engines. Such large internal combustion engines can be designed as diesel engines, gas engines, or dual-fuel engines. In dual-fuel engines, a liquid fuel, in particular a diesel fuel, can be burned in a first operating state, and a gaseous fuel, in particular natural gas, can be burned in a second operating state.

[0003] Exhaust gas aftertreatment is also playing an increasingly important role in the field of large internal combustion engines. DE 10 2016 205 327 A1, for example, describes an exhaust gas aftertreatment system that can be used in large internal combustion engines. The exhaust gas aftertreatment system disclosed therein has a reactor chamber, with an SCR catalyst arranged in the reactor chamber. It is known that such an SCR catalyst has several exhaust gas aftertreatment units connected in parallel, through which exhaust gas flows, wherein each exhaust gas aftertreatment unit has a honeycomb body that is held by a honeycomb body carrier and is arranged in a receiving housing via the honeycomb body carrier. The honeycomb body carrier is also referred to as a canning, which surrounds the respective honeycomb body on the outside, leaving its end faces free.

[0004] To date, the arrangement of the exhaust gas aftertreatment units in the receiving housing has been difficult in that it is only with great effort that it can be ensured that the exhaust gas flows completely through the honeycomb body and does not flow past the honeycomb body via gaps between the honeycomb body carrier and the receiving housing.

[0005] EP 3 147 472 A1 discloses an exhaust gas aftertreatment system of an internal combustion engine according to the preamble of claim 1.

[0006] DE 22 36 592 A1 and DE 34 06 721 A1 disclose further prior art.

[0007] Based on this, the invention is based on the object of creating a novel exhaust gas aftertreatment system for an internal combustion engine.

[0008] This object is achieved by an exhaust gas aftertreatment system device according to claim 1.

[0009] The preloading elements acting in the flow direction and perpendicular to the flow direction of the respective exhaust aftertreatment unit ensure that the exhaust gas is guided through the at least one honeycomb body of the at least one exhaust aftertreatment unit and does not flow past the honeycomb body via gaps between the honeycomb body support of the respective honeycomb body and the receiving housing. This can be achieved with minimal effort using the first preloading elements acting in the flow direction of the respective exhaust aftertreatment unit and the second preloading elements acting perpendicular to the flow direction of the respective exhaust aftertreatment unit.

[0010] Preferably, the first prestressing elements acting in the flow direction of the respective exhaust gas aftertreatment unit and the second prestressing elements acting perpendicular to the flow direction of the respective exhaust gas aftertreatment unit are formed by separate prestressing assemblies, wherein each separate prestressing assembly has a first prestressing element acting in the flow direction of the respective exhaust gas aftertreatment unit and a plurality of second prestressing elements acting perpendicular to the flow direction of the respective exhaust gas aftertreatment unit, and wherein the separate prestressing assemblies are plugged onto the respective exhaust gas aftertreatment unit at at least one of opposite axial ends of the same, namely onto the honeycomb body carrier of the respective exhaust gas aftertreatment unit.If the preload elements are formed by separate preload assemblies that are plugged onto the respective exhaust aftertreatment unit, the preload assemblies can be reused, in particular if an exhaust aftertreatment unit has to be replaced, for example due to a blocked honeycomb body.

[0011] Preferably, the first prestressing elements acting in the flow direction of the respective exhaust gas aftertreatment unit are designed as bellows-like prestressing elements. The prestressing of the respective exhaust gas aftertreatment unit in the flow direction of the respective exhaust gas aftertreatment unit can be provided simply and advantageously via bellows-like prestressing elements.

[0012] Preferably, the second prestressing elements acting perpendicular to the flow direction of the respective exhaust gas aftertreatment unit are designed as latch-like projections. The prestressing of the respective exhaust gas aftertreatment unit perpendicular to the flow direction of the respective exhaust gas aftertreatment unit can be provided simply and reliably via latch-like projections.

[0013] Preferably, the pawl-like projections form an angle of 90° with the flow direction. When the pawl-like projections form an angle of 90° with the flow direction, the respective exhaust gas aftertreatment unit can be arranged particularly advantageously in the receiving housing together with the preloading elements.

[0014] Preferably, sealing surfaces on the first preloading elements acting in the flow direction of the respective exhaust aftertreatment unit are aligned perpendicular to the flow direction of the respective exhaust aftertreatment unit. This is particularly advantageous when multiple exhaust aftertreatment units are arranged one behind the other in a series connection in a receiving housing. In this case, a manufacturing tolerance in the area of ​​the exhaust aftertreatment unit ensures that the sealing effect on the sealing surfaces is not impaired.

[0015] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 a cross section through an example of an exhaust gas aftertreatment device of an internal combustion engine not according to the invention, Fig. 2 a detail of theFig. 1 in exploded view, Fig. 3 a cross section through an example of a further exhaust gas aftertreatment device of an internal combustion engine not according to the invention, Fig. 4 a detail of the Fig. 3 , Fig. 5an alternative to the detail of the Fig. 4 , Fig. 6 another detail of the Fig. 3 , Fig. 7an alternative to the detail of the Fig. 6 , Fig. 8 another alternative to the detail of the Fig. 6 , Fig. 9another alternative to the detail of the Fig. 6 , Fig. 10 another detail of the Fig. 1 or 3 , Fig. 11 a section of an alternative to the detail of the Fig. 10 ; Fig. 12 a cross section through a further example of an exhaust gas aftertreatment device of an internal combustion engine not according to the invention, Fig. 13 a detail of the Fig. 12 , Fig. 14an alternative to the detail of the Fig. 13, Fig. 15 a cross section through a further example of an exhaust gas aftertreatment device of an internal combustion engine not according to the invention, Fig. 16 a cross section through a further example of an exhaust gas aftertreatment device of an internal combustion engine not according to the invention, Fig. 17 a cross section through an example of an exhaust gas aftertreatment system of an internal combustion engine according to the invention, Fig. 18 a detail of the Fig. 17 in exploded view, Fig. 19 the detail of the Fig. 18 in assembly, Fig. 20 a cross section through an example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention, Fig. 21 a cross section through an example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention, Fig. 22 a detail of the Fig. 21 , Fig. 23 an exploded view of the Fig. 22, Fig. 24 a cross section through a further example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention, Fig. 25 the cross section AA of the Fig. 24 , Fig. 26 a cross section through a further example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention, Fig. 27 the cross section BB of the Fig. 26 , Fig. 28 a cross section through a further example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention, Fig. 29 the cross section CC of the Fig. 28 , Fig. 30 a side view of another example of an exhaust gas aftertreatment system of an internal combustion engine not according to the invention.

[0016] The invention relates to an exhaust aftertreatment system for an internal combustion engine, in particular a large internal combustion engine. A large internal combustion engine is, in particular, a marine engine, which can be configured as a diesel engine, a gas engine, or a dual-fuel engine. A large internal combustion engine has cylinders with a piston diameter of at least 140 mm, in particular of at least 175 mm.

[0017] Fig. 1 shows details of an exhaust gas aftertreatment device 40 not according to the invention. The exhaust gas aftertreatment device 40 has a receiving housing 41 and, in the example shown, a plurality of exhaust gas aftertreatment units 42 arranged in the receiving housing 41. In Fig. 1 two exhaust aftertreatment units 42 connected in series are shown, both of which are arranged in the receiving housing 41.

[0018] The receiving housing 41 is in Fig. 1, 2tubular in design. A flow direction through the receiving housing 41 or the exhaust aftertreatment units 42 arranged in the receiving housing 41 extends in the axial direction thereof. If the tubular receiving housing 41 and the exhaust aftertreatment units 42 arranged in the receiving housing 41 are circular in cross-section, the radial direction of the receiving housing 41 or the exhaust aftertreatment units 42 arranged in the receiving housing 41 extends perpendicular to the flow direction thereof. The cross sections of the receiving housing 41 and the exhaust aftertreatment units 42 can also be rectangular, square, oval, or the like.

[0019] Each exhaust gas aftertreatment unit 42 has a honeycomb body 43 serving as a catalyst and / or particulate filter, as well as a honeycomb body support 44 surrounding the honeycomb body 43 on the outside and leaving the honeycomb body 43 free at the end faces thereof. The honeycomb body support 44 is also referred to as a canning. According to Fig. 1 and 2 A fiber mat 45 is arranged between the honeycomb body 43 and the honeycomb support 44 of the exhaust aftertreatment units 42 shown there. The fiber mat 45 also leaves the end faces of the respective honeycomb body 43, which define an inlet side and an outlet side for the exhaust gas, exposed.

[0020] The respective exhaust gas aftertreatment unit 43 is pre-tensioned in the receiving housing 41 via pre-tensioning elements.

[0021] Thus, the respective exhaust gas aftertreatment unit 42 is positioned in the receiving housing 41 in a prestressed manner both via first prestressing elements 46 acting in the flow direction of the exhaust gas aftertreatment unit 42 and via second prestressing elements 47 acting perpendicular to the flow direction of the respective exhaust gas aftertreatment unit 42. The prestressing elements 46, 47 effect a spring-elastic prestress of the respective exhaust gas aftertreatment unit 42 in the receiving housing 41 in the flow direction and perpendicular to the flow direction.

[0022] In Fig. 1 and 2 the first prestressing elements 46 acting in the flow direction or in the axial direction of the respective exhaust gas aftertreatment unit 42 and the second prestressing elements 47 acting perpendicular to the flow direction or in the radial direction of the respective exhaust gas aftertreatment unit 42 are formed by separate prestressing assemblies 48.

[0023] These separate preload assemblies 48 can be seen in particular in the exploded view of the Fig. 2 Each separate prestressing assembly 48 has a first prestressing element 46 acting in the flow direction of the respective exhaust gas aftertreatment unit 42 and a plurality of second prestressing elements 47 acting perpendicular to the flow direction of the respective exhaust gas aftertreatment unit 42.

[0024] The separate preload assemblies 48 are in Fig. 1, 2 at opposite axial ends of the respective exhaust gas aftertreatment unit 42, namely on the honeycomb body support 44 of the respective exhaust gas aftertreatment unit 42, again leaving free the end faces of the respective honeycomb body 43, which serve as the inlet side and the outlet side of the respective honeycomb body 43 and thus of the respective exhaust gas aftertreatment unit 42 for the exhaust gas to be cleaned.

[0025] If the receiving housing 41 has a circular cross-section as viewed in the flow direction, the exhaust aftertreatment units 42 and the separate preload assemblies 48 also have a circular cross-section. In this case, a plurality of second preload elements 47, which then serve to preload in the radial direction, are distributed around the circumference of the preload elements 48.

[0026] The cross-sectional contour of the receiving housing 41 and the exhaust aftertreatment units 42 can also be rectangular, square, oval or the like.

[0027] In Fig. 1 and 2 the first prestressing elements 46 acting in the flow direction of the respective exhaust gas aftertreatment unit 42 are designed as bellows-like prestressing elements.

[0028] The second prestressing elements 47, which act perpendicular to the flow direction of the respective exhaust aftertreatment unit 42, are designed as pawl-like projections that are bent radially outward from the respective prestressing assembly 48. These second prestressing elements 47, preferably designed as pawl-like projections, are supported on an inner wall 49 of the receiving housing 41.

[0029] The first prestressing elements 46, which act in the flow direction of the respective exhaust gas aftertreatment unit 42 and are preferably designed as bellows, are supported on an adjacent first prestressing element 46 of the adjacent exhaust gas aftertreatment unit 42 when a further exhaust gas aftertreatment unit 42 is connected to an exhaust gas aftertreatment unit 42. Otherwise, these first prestressing elements 46, which are designed like bellows, are supported on a radially inwardly extending projection 50 of the receiving housing 41.

[0030] How Fig. 2can be removed, not only the outwardly projecting second pre-tensioning elements 47 are formed on the separate pre-tensioning assemblies 48, but also third pre-tensioning elements 51 projecting radially inwards. These radially inwardly projecting third pre-tensioning elements 51 serve to pre-tension the exhaust gas after-treatment unit 42 in the separate pre-tensioning assemblies 48. These radially inwardly projecting pre-tensioning elements 51 are accordingly supported in a spring-elastic manner on the honeycomb carrier 44 of the respective exhaust gas after-treatment unit 42.

[0031] According to Fig. 1Sealing surfaces 52 on the first prestressing elements 46 acting in the flow direction run perpendicular to the flow direction of the respective exhaust gas aftertreatment unit 42. This is advantageous in order to avoid manufacturing tolerances in the area of ​​the exhaust gas aftertreatment units 42 impairing the sealing effect between adjacent first prestressing elements 46 of adjacent exhaust gas aftertreatment units 42.

[0032] Fig. 3 shows a partial cross-section through a further exhaust gas aftertreatment device 53 not according to the invention, which, with regard to its basic structure, is similar to the exhaust gas aftertreatment device 40 of the Fig. 1 Therefore, the same reference numbers are used for the same components and the following descriptions are made with reference to Fig. 3 details have been discussed which distinguish the exhaust gas aftertreatment device 53 of the Fig. 3 from the exhaust aftertreatment unit 40 of the Fig. 1 While in Fig. 1 the first biasing elements 46 and the second biasing elements 47 are both provided by separate biasing assemblies 48, are in Fig. 3 Both the first preload elements 46 and the second preload elements 47 are designed as an integral component of the honeycomb support 44 and thus of the canning. Although this reduces the number of individual assemblies, the preload elements 46, 47 cannot be reused when an exhaust aftertreatment unit 42 is replaced.

[0033] Fig. 4 which is a detail of the Fig. 3 in the region of the adjacent first prestressing elements 46 of the adjacent exhaust gas aftertreatment units 42, it can be seen that the sealing surfaces 52 of the first prestressing elements 46 run perpendicular to the flow direction of the exhaust gas aftertreatment units 42.

[0034] In contrast, Fig. 5a variation for the detail of the Fig. 4 , in which the sealing surfaces 52 of the adjacent first prestressing elements 46 of adjacent exhaust gas aftertreatment units 42 do not run perpendicular to the flow direction of the respective exhaust gas aftertreatment units 42, but rather are inclined with respect to the radial direction, which runs perpendicular to the flow direction.

[0035] Fig. 6 to 11 show details and possible designs of the second prestressing elements 47. Thus, in Fig. 6 shown that the second prestressing element 47 shown there is again an integral part of the honeycomb support 44 or the canning, wherein both the honeycomb support 44 and the second prestressing element 47, which is designed as a latch-like projection, are each single-walled. In contrast, Fig. 7a configuration in which the honeycomb support 44 is multi-walled, namely double-walled, and the second prestressing element 47, which is designed as a latch-like projection, is single-walled. Fig. 8 , which shows a further modification, both the honeycomb support 44 and the second prestressing element 47 shown are each multi-walled. Of the Figs. 6, 7 and 8 The variants shown have the variant of the Fig. 7 the advantage that the fiber mat 45 is supported over its entire axial extent by the honeycomb receiving body 44 and, moreover, the second prestressing element 47 can be easily formed.

[0036] Although Figs. 6, 7 and 8 refer to second prestressing elements 47, which are designed as an integral part of the honeycomb carrier 44, it should be noted that the variants of the Figs. 6, 7 and 8 also in the exhaust aftertreatment device 40 of the Fig. 1can be used. Here, the single-wall or multi-wall design does not refer to the honeycomb support 44, but rather to the separate prestressing assemblies 46, which provide the prestressing elements 46 and 47.

[0037] Fig. 9 shows a modification of the Fig. 6 , in which the second prestressing element 47 shown there is single-walled and designed in the shape of a bridge. This is again an integral part of the honeycomb carrier 44. Also in Fig. 9 The multi-walled nature of the Figs. 7 and 8 can also be used in Fig. 1, 2 a second prestressing element 47 may be designed in bridge form.

[0038] Fig. 10 shows a development of either a separate prestressing assembly 48 or a honeycomb carrier 44 in the region of second prestressing elements 47. In Fig. 10only the second pre-tensioning elements 47 are shown, which are projected radially outwards and, in the installed state, come into contact with the inner surface 49 of the receiving housing 41. As already explained, these second pre-tensioning elements 47 are preferably blade-like projections, wherein these pawl-like projections enclose an angle α or an angle β with the flow direction of the respective exhaust gas aftertreatment unit 42. In the area of ​​the inlet-side end of the respective exhaust gas aftertreatment unit 42, the second pre-tensioning elements 47 enclose the angle α and in the area of ​​the outlet-side end, the second pre-tensioning elements 47 enclose the angle β with the flow direction of the respective exhaust gas aftertreatment unit 42, wherein the pawl-like projections according to Fig. 10preferably opposite or offset by 180°. Both angles α and β can be the same or different.

[0039] A particularly preferred embodiment is one in which both the angle α and the angle β are each 90°. In this case, the second prestressing elements 47 also advantageously define insertion ramps for the exhaust gas aftertreatment units 42 into the receiving housing 41.

[0040] Fig. 12 shows a further example of an exhaust gas aftertreatment device 54 not according to the invention. Also for Fig. 12 For identical assemblies, the same reference numbers are used as in Fig. 1 used. In Fig. 12 The second clamping elements 47, which are again designed as latch-like projections and are located on the wall 49 of the receiving housing 41, are an integral part of the honeycomb support 44 and thus of the canning. In this respect, Fig. 12 the Fig. 3 . However, the first preloading elements 46 acting in the flow direction of the exhaust gas aftertreatment units 42 are in Fig. 12 as in Fig. 1 again designed as separate assemblies, but in contrast to the Fig. 1 a separate first prestressing element 46 is not attached to both axial ends of a respective exhaust gas aftertreatment unit 42, but only to one axial end thereof.

[0041] Fig. 13 shows a detail of the Fig. 6 in the area of ​​two adjacent exhaust aftertreatment units 42. According to Fig. 13 the sealing surface 52 between the Fig. 13 shown first prestressing element 46 and an adjacent section of the honeycomb carrier 44 of the adjacent exhaust aftertreatment unit 42 is inclined relative to the radial direction, which runs perpendicular to the flow direction. Fig. 14 , which is a modification of the detail of the Fig. 13shows such an inclined position of the sealing surface 52, which, however, in contrast to Fig. 13 is inclined towards the adjacent exhaust aftertreatment unit 42 and not, as in Fig. 13 shown, is tilted away from it.

[0042] Figs. 15 and 16 show further examples of exhaust aftertreatment devices 55 and 56. The exhaust aftertreatment units 55 and 56 of the Figs. 15 and 16 basically correspond to the exhaust aftertreatment unit 53 of the Fig. 3 , also in Figs. 15 and 16 Accordingly, the first prestressing elements 46 and the second prestressing elements 47 are designed as integral components of the honeycomb body supports 44 and thus of the respective canning.

[0043] The examples of Figs. 15 and 16 However, they differ from that of the Fig. 3in that the first prestressing elements 46 acting in the flow direction of the respective exhaust gas aftertreatment unit 42 are not designed like bellows, but rather are formed by a corresponding wall thickness of the honeycomb body carrier 44.

[0044] The Figs. 15 and 16 differ from each other in that Fig. 16 Adjacent exhaust aftertreatment units 42 do not seal directly against each other in the region of the first prestressing elements 46, but rather against a radially inwardly projecting projection 50 of the receiving housing 41.

[0045] Fig. 17 shows an embodiment of an exhaust gas aftertreatment system 57 according to the invention, which comprises two exhaust gas aftertreatment devices 53 according to Fig. 3 Each of the two exhaust gas aftertreatment devices 53 has a receiving housing 41 and two exhaust gas aftertreatment units 42 positioned in the receiving housing 41.

[0046] The two exhaust gas aftertreatment devices 53 are connected in series. Exhaust gas, which the exhaust gas aftertreatment system 57 of the Fig. 17 flows through, therefore flows through all exhaust aftertreatment units 42. The exhaust aftertreatment system 57 of the Fig. 17 is single-flow.

[0047] According to Fig. 17 A housing 58 is connected between the two exhaust aftertreatment devices 53, which serves, for example, to accommodate sensors such as temperature sensors or pressure sensors. Additionally, the housing 58 can accommodate, for example, a device for introducing a reducing agent into the exhaust gas stream. The housing 58 can also accommodate a soot blower.

[0048] Covers 59 are connected to the opposite ends of the two exhaust gas aftertreatment devices 53, whereby the covers 59 of the exhaust gas aftertreatment system 57 can be connected to exhaust pipes (not shown).

[0049] Figs. 18 and 19 show details of the connection of the receiving housing 41 of one of the Fig. 17 shown exhaust aftertreatment devices 53 with one of the covers 59. With the cover 59 removed (see Fig. 18 ) the corresponding end of the corresponding exhaust aftertreatment unit 42 is provided with a defined preload stroke VH in the direction of flow out of the receiving housing 41.

[0050] With cover 59 fitted (see Fig. 19 ), the prestressing elements 46 of the exhaust gas aftertreatment units 42 arranged in the receiving housing 41, which act in the flow direction, are compressed in order to bring a flange 60 of the cover 59 into contact with a flange 61 of the receiving housing 41 and then to connect the cover 59 and the receiving housing 41 to one another, for example by screwing.

[0051] Fig. 20shows a cross section through a second exhaust gas aftertreatment system 62, which has only a single exhaust gas aftertreatment device 53, with the covers 59 directly adjoining it on both sides.

[0052] In Fig. 20 At the left end of the exhaust aftertreatment device 53, an intermediate disk 63 is used between the flange 61 of the receiving housing 41 and the flange 60 of the cover 59 to connect the cover 59 to the receiving housing 41 while compressing the first preload elements 46. The preload force in the flow direction can be adjusted via the intermediate disk 53.

[0053] Figs. 21, 22 and 23 show details of a third exhaust aftertreatment system 64 with an exhaust aftertreatment device 54 according to Fig. 12 . However, with regard to all other details, Figs. 21, 22 and 23 with the Fig. 20 and with regard to the connection of the cover 59 to the receiving housing 41 with the details of the Figs. 18 and 19 so that the same reference numbers are used for the same assemblies and reference can be made to the above explanations.

[0054] It should be noted that in Fig. 17 to 23 also the exhaust aftertreatment devices 40 of the Fig. 1, 2 can be installed in an exhaust aftertreatment system, as well as the exhaust aftertreatment devices 55, 56 of the Figs. 15 and 16 .

[0055] While Fig. 17 to 23 details of single-flow exhaust aftertreatment systems 57, 62, 64 show, show Figs. 24, 25 and Figs. 26, 27 and Figs. 28, 29 as well as Fig. 30 Different views of multi-flow exhaust aftertreatment systems 65, 66, 67 and 68. Figs. 24 and 25 show a multi-flow exhaust aftertreatment system 65, which comprises a total of five parallel-connected exhaust aftertreatment devices 40 according to Fig. 1 includes, but with the difference that Figs. 24 and 25in the respective housing three exhaust gas aftertreatment units 42 are connected in series and not, as in Fig. 1, 2 only two exhaust aftertreatment units 42.

[0056] In Figs. 24 and 25 A common cover 59 is connected to the respective ends of the five parallel-connected exhaust aftertreatment devices 40. In Figs. 24 and 25 Between the flange 60 of the left cover 59 and the flange 61 of the housing 41, a clamping cover 69 is used which is common to all housings 41 of all parallel connected exhaust aftertreatment devices 40 and which also performs the function of the intermediate disc 63 of the Fig. 20 takes over.

[0057] In contrast, Figs. 28 and 29an exhaust gas aftertreatment system 67, in which an individual clamping cover 69 is used for each exhaust gas aftertreatment device 40 between the left cover 59 and the receiving housings 41 of the parallel-connected exhaust gas aftertreatment devices 40.

[0058] For the exhaust aftertreatment systems 65 and 67 of the Figs. 24, 25 or the Figs. 28, 29 the inflow side and the outflow side are arranged at opposite ends of the respective exhaust gas aftertreatment system 65, 67. In contrast, Figs. 26 and 27 an exhaust aftertreatment system 66, in which the inflow side and outflow side of the exhaust aftertreatment system 26 are formed at the same end or the same side of the exhaust aftertreatment system 66.

[0059] In Figs. 26 and 27 Four exhaust aftertreatment devices 40 are connected in parallel, namely between the covers 59. While in Figs. 24 and 25one of the covers 59 forms an inlet side and the opposite cover 59 forms an outlet side of the respective exhaust gas aftertreatment system, are in Figs. 26 and 27 Inlet side and outlet side on the right cover 59 of the Fig. 6 A flow reversal for the exhaust gas takes place on the opposite cover 59. Such a flow reversal for the exhaust gas is already known from DE 10 2016 205 327 A1. In Fig. 26 Arrows illustrate the exhaust gas flow through the exhaust aftertreatment system 66 of the Figs. 26 and 27 .

[0060] Fig. 30 shows an exhaust gas aftertreatment system 68 in which two exhaust gas aftertreatment devices 14 are arranged in series one behind the other and several such series circuits are arranged parallel to one another between two covers 59. In accordance with Fig. 17Between two exhaust aftertreatment devices 40 connected in series, a housing 58 for accommodating a sensor system or for accommodating soot blowers or for accommodating introducing devices for reducing agents can be arranged. Fig. 30 The flow of the exhaust gas can be either as in Figs. 24, 25 or as in Figs. 26, 27 be executed.

[0061] If several exhaust gas aftertreatment units 42 are arranged in a receiving housing 41, and / or if several exhaust gas aftertreatment devices are connected in series, the series-connected exhaust gas aftertreatment units 42 can be identical or different. For example, it is possible that in the exemplary embodiment of the Fig. 17The two left-hand exhaust aftertreatment units 42 are designed as particulate filters, and the two right-hand exhaust aftertreatment units 42 are designed as SCR catalysts or NOx storage catalysts. It is also possible to leave a position of an exhaust aftertreatment unit 42 free and simply arrange a placeholder there, which cannot perform any exhaust aftertreatment function.

[0062] The prestressing forces for the prestressing elements 46, 47 can be adjusted, in particular, by selecting the material and / or the wall thickness and / or the geometry and / or the number of walls of the prestressing elements 46, 47. As explained above, the prestressing elements 46, 47 can be single-walled or multi-walled.

[0063] The number of bellows or corrugations in the bellows-like prestressing elements 46 can be varied. The number of bellows or corrugations in the pawl-like prestressing elements 47 can be varied.

[0064] An exhaust aftertreatment system can be expanded as needed from the above-described components of the housing 41, exhaust aftertreatment units 42, housing 58, and cover 59 in a modular system. Housing 41 and exhaust aftertreatment units 42 can be designed with coarse tolerances. The preloading elements 26, 27 compensate for such tolerances. The preloading elements 26, 27 also provide vibration damping and reduce vibrations in the exhaust system. List of reference symbols

[0065] 40 Exhaust aftertreatment device 41 Housing 42 Exhaust aftertreatment unit 43 Honeycomb body 44 Honeycomb support 45 Fiber mat 46 First preload element 47 Second preload element 48 Preload assembly 49 Inner surface 50 Projection 51 Third preload element 52 Sealing surface 53 Exhaust aftertreatment device 54 Exhaust aftertreatment device 55 Exhaust aftertreatment device 56 Exhaust aftertreatment device 57 Exhaust aftertreatment system 58 Housing 59 Cover 60 Flange 61 Flange 62 Exhaust aftertreatment system 63 Intermediate disk 64 Exhaust aftertreatment system 65 Exhaust aftertreatment system 66 Exhaust aftertreatment system 67 Exhaust aftertreatment system 68 Exhaust aftertreatment system 69 Clamping cover

Claims

1. An exhaust gas after-treatment system (57) of an internal combustion engine, having an exhaust gas after-treatment device (53) having a receiving housing (41), having at least one exhaust gas after-treatment unit (42) arranged in the receiving housing (41), which comprises a honeycomb body (43) serving as catalytic converter and / or as particulate filter and a honeycomb body carrier (44) surrounding the honeycomb body (43) exposing the honeycomb body (43) on the front sides of the same, the at least one exhaust gas after-treatment unit (42) is received in the receiving housing (41) in a preloaded manner via first preload elements (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) and via second preload elements (47) acting perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42), having lids (59) for connecting the exhaust gas after-treatment system (57) to exhaust lines, having multiple exhaust gas after-treatment devices (53) connected in series one behind the other, characterised in that between two exhaust gas after-treatment devices (53) a housing (58) is connected, which serves at least for receiving sensors, such as, for example, temperature sensors or pressure sensors.

2. The exhaust gas after-treatment system (57) according to Claim 1, characterised in that the housing (58) connected between two exhaust gas after-treatment devices (53) further serves for receiving a device for introducing a reduction agent into the exhaust gas flow and / or a soot blower.

3. The exhaust gas after-treatment system (57) according to Claim 1 or 2, characterised in that the first preload elements (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) and the second preload elements (47) acting perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42) are formed by separate preload assemblies (48), each separate preload assembly (48) comprises a first preload element (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) and multiple second preload elements (47) acting perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42), the separate preload assemblies (48) on at least one of axially opposite ends of the respective exhaust gas after-treatment unit (42) are plugged onto the same, namely, onto the honeycomb body carrier (44) of the respective exhaust gas after-treatment unit (42).

4. The exhaust gas after-treatment system (57) according to Claim 3, characterised in that the separate preload assemblies (48) are single-walled or multi-walled.

5. The exhaust gas after-treatment system (57) according to Claim 1, characterised in that the first preload elements (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) and / or the second preload elements (47) acting perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42) are designed as integral part of the honeycomb body carrier (44) of the respective exhaust gas after-treatment unit (42).

6. The exhaust gas after-treatment system (57) according to Claim 5, characterised in that the honeycomb body carrier (44) of the respective exhaust gas after-treatment unit (42) is single-walled or multi-walled.

7. The exhaust gas after-treatment system (57) according to any one of the Claims 1 to 6, characterised in that the first preload elements (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) are designed as bellows-type preload elements.

8. The exhaust gas after-treatment system (57) according to any one of the Claims 1 to 7, characterised in that the second preload elements (47) acting perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42) are designed as pawl-like projections.

9. The exhaust gas after-treatment system (57) according to Claim 8, characterised in that the pawl-like projections are single-walled or multi-walled.

10. The exhaust gas after-treatment system (57) according to any one of the Claims 1 to 9, characterised in that sealing surfaces (52) on the first preload elements (46) acting in the flow direction of the respective exhaust gas after-treatment unit (42) are oriented perpendicularly to the flow direction of the respective exhaust gas after-treatment unit (42).