JP2017187033A - Exhaust gas post-treatment device and internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact exhaust gas post-treatment system used in an internal combustion engine of a power plant, a ship and the like.SOLUTION: A SCR exhaust gas post-treatment system has a SCR catalyst converter 9, an exhaust gas supply conduit 8 reaching the SCR catalyst converter, an exhaust gas discharge conduit 11 extended from the SCR catalyst converter, and a reducer introduction device disposed in the exhaust gas supply conduit. An exhaust gas back pressure booster 25 is disposed between a downstream-side end portion 15 of the exhaust gas supply conduit and an upstream-side of the SCR catalyst converter, so that the exhaust gas flow to the SCR catalyst converter is equalized in a circumferential direction and a radial direction. Further, soot particles accumulated on the exhaust gas back pressure booster and the SCR catalyst converter are purged by a blow device 24.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an exhaust gas aftertreatment system for an internal combustion engine. Furthermore, the present invention relates to an internal combustion engine having an exhaust gas aftertreatment system.

  For example, in combustion processes in stationary internal combustion engines, such as those used in power plants, and combustion processes in non-fixed internal combustion engines, such as those used in ships, nitrogen oxides are generated and these nitrogen oxides are It typically occurs upon combustion of fossil fuels containing sulfur such as coal, bituminous coal, lignite, petroleum, heavy oil or diesel fuel. Accordingly, such an internal combustion engine is provided with an exhaust gas aftertreatment system used for purification of exhaust gas discharged from the internal combustion engine, particularly for denitrification.

In order to reduce the nitrogen oxides in the exhaust gas, a so-called SCR catalytic converter is first used in an exhaust gas aftertreatment system known from practice. In the SCR catalytic converter, selective catalytic reduction of nitrogen oxides is performed, and ammonia (NH ₃ ) is required as a reducing agent for the reduction of nitrogen oxides. For this purpose, ammonia or ammonia precursor urea or the like is introduced into the exhaust gas in the form of a liquid upstream of the SCR catalytic converter, and the ammonia or ammonia precursor is mixed with the exhaust gas upstream of the SCR catalytic converter. . For this purpose, according to practice, a mixing section is provided between the introduction part of the ammonia or ammonia precursor and the SCR catalytic converter.

  Although exhaust gas aftertreatment, in particular nitrogen oxide reduction, can already be successfully carried out using exhaust gas aftertreatment systems, including SCR catalytic converters, it is necessary to further improve the exhaust gas aftertreatment system Sex exists. In particular, when the structure of such an exhaust gas aftertreatment system is downsized, there is a need to enable effective exhaust gas aftertreatment.

  Based on such a need, an object of the present invention is to create a new type exhaust gas aftertreatment system for an internal combustion engine and an internal combustion engine having such an exhaust gas aftertreatment system.

  This problem is solved by the exhaust gas aftertreatment system for an internal combustion engine according to claim 1.

  According to the invention, the exhaust gas supply conduit leads to a reaction chamber at the downstream end that receives the SCR catalytic converter, and is located inside the reaction chamber between the downstream end of the exhaust gas supply conduit and the SCR catalytic converter. An exhaust gas back pressure raising device is arranged upstream of the SCR catalytic converter. Using an exhaust gas back pressure riser upstream of the SCR catalytic converter, the exhaust gas flow is damped upstream of the SCR catalytic converter, so that the exhaust gas flow is evenly distributed in the circumferential and radial directions to the SCR catalytic converter. Can be supplied. Thereby, effective exhaust gas purification can be ensured in the exhaust gas aftertreatment system having a miniaturized structure. Furthermore, since the soot particles can accumulate in the exhaust gas back pressure raising device, the soot particles no longer reach the region of the SCR catalytic converter and clog the SCR catalytic converter. This also helps to ensure effective exhaust gas purification in an exhaust gas aftertreatment system with a miniaturized structure.

  According to an advantageous further development, the exhaust gas back pressure raising device has a flow cross section that is free to flow, which is at most twice the free flow cross section of the SCR catalytic converter, preferably at most 1 Double, particularly preferably up to 0.5. This further development allows a particularly effective exhaust gas aftertreatment with a smaller structure.

  According to an advantageous further development, the ratio of the thickness or length in the flow direction of the exhaust gas back pressure raising device to the thickness or length in the flow direction of the SCR catalytic converter is at least 1:50, preferably at least 1: 100. Particularly preferred is at least 1: 200. This further development allows a particularly effective exhaust gas aftertreatment with a smaller structure.

  According to an advantageous further development, the ratio of the distance in the flow direction between the exhaust gas back pressure raising device and the SCR catalytic converter to the thickness or length in the flow direction of the SCR catalytic converter is at most 2 : 1, preferably at most 1: 1, particularly preferably at most 1: 2. This further development allows a particularly effective exhaust gas aftertreatment with a smaller structure.

  According to an advantageous further development, at least one blow device is arranged inside the reaction chamber between the exhaust gas back pressure raising device and the SCR catalytic converter, the blow device being a purge of the exhaust gas back pressure raising device. And / or used to purge the SCR catalytic converter. This further development allows a particularly effective exhaust gas aftertreatment with a smaller structure.

  An internal combustion engine according to the present invention is defined in claim 14.

  Preferred further developments of the invention emerge from the subclaims and the following description. Embodiments of the present invention will be described in detail with reference to the drawings, but are not limited thereto. The following figure is shown.

1 is a schematic perspective view of an internal combustion engine having an exhaust gas aftertreatment system according to the present invention. It is a figure which shows the detail of the waste gas aftertreatment system which concerns on FIG. It is a figure which shows the detail of FIG. It is a figure which shows the detail of FIG. 3 in a cross section.

  The present invention relates to an exhaust gas aftertreatment system for an internal combustion engine, such as a fixed internal combustion engine of a power plant or an unfixed internal combustion engine used in a ship. In particular, the exhaust gas aftertreatment system is used in marine diesel internal combustion engines operating on heavy oil.

  FIG. 1 shows an assembly consisting of an internal combustion engine 1 having an exhaust gas turbocharger system 2 and an exhaust gas aftertreatment system 3. The internal combustion engine 1 may be an unfixed or a fixed internal combustion engine, in particular a marine internal combustion engine that operates without being fixed. The exhaust gas discharged from the cylinder of the internal combustion engine 1 is used in the exhaust gas turbocharger system 2 to obtain mechanical energy for compressing the supercharged air to be supplied to the internal combustion engine 1 from the thermal energy of the exhaust gas. .

  FIG. 1 shows an internal combustion engine 1 having an exhaust gas turbocharger system 2, the exhaust gas turbocharger system comprising a plurality of exhaust gas turbochargers, namely a first, high-pressure side exhaust gas turbocharger 4, a second, And a low-pressure side exhaust gas turbocharger 5. The exhaust gas discharged from the cylinder of the internal combustion engine 1 first flows through the high-pressure turbine 6 of the first exhaust gas turbocharger 1 and expands in the high-pressure turbine, and the energy obtained at that time In order to compress, it is used in the high pressure compressor of the first exhaust gas turbocharger 4. A second exhaust gas turbocharger 5 is arranged downstream of the first exhaust gas turbocharger 4 as viewed in the direction in which the exhaust gas flows, and the exhaust gas that has already flowed through the high-pressure turbine 6 of the first exhaust gas turbocharger 4 is , Through the second exhaust gas turbocharger 5, that is, through the low pressure turbine 7 of the second exhaust gas turbocharger 5. In the low-pressure turbine 7 of the second exhaust gas turbocharger 5, the exhaust gas further expands, and the energy obtained at that time is supplied to the cylinder of the internal combustion engine 1 in the same manner in the low-pressure compressor of the second exhaust gas turbocharger 5. Used to compress the supercharged air to be done.

  In addition to the exhaust gas turbocharger system 2 having both exhaust gas turbochargers 4 and 5, the internal combustion engine 1 includes an exhaust gas aftertreatment system 3, which is an SCR exhaust gas aftertreatment system. Since the SCR exhaust gas aftertreatment system 3 is connected between the high pressure turbine 6 of the first compressor 5 and the low pressure turbine 7 of the second exhaust gas turbocharger 5, the high pressure turbine of the first exhaust gas turbocharger 4. The exhaust gas discharged from 6 can be first guided through the SCR exhaust gas aftertreatment system 3 before reaching the area of the low pressure turbine 7 of the second exhaust gas turbocharger 5.

  FIG. 1 shows an exhaust gas supply conduit 8 through which the exhaust gas flows from a high pressure turbine 6 of a first exhaust gas turbocharger 4 of an SCR catalytic converter 9 disposed in a reaction chamber 10. It can be guided in the direction.

  Furthermore, FIG. 1 shows an exhaust gas discharge conduit 11, which is used to exhaust the exhaust gas from the SCR catalytic converter 9 in the direction of the low pressure turbine 7 of the second exhaust gas turbocharger 5. The exhaust gas flows from the low-pressure turbine 7 through the conduit 21 and in particular outdoors.

  An advantageous application in a single-stage turbocharged engine in which the positioning takes place upstream of the turbine is not shown.

  Exhaust gas supply conduit 8 extending to the reaction chamber 10 and thus to the SCR catalytic converter 9 disposed inside the reaction chamber 10, and an exhaust gas exhaust conduit extending to be separated from the reaction chamber 10 and thus the SCR catalytic converter 9. 11 is connected via a bypass 12 containing a blocking element 13. When the blocking element 13 is closed, the bypass 12 is also closed, so that the exhaust gas cannot flow through the bypass 12. In contrast, particularly when the shut-off element 13 is open, the exhaust gas can pass through the bypass 12, i.e. pass through the reaction chamber 10 and thus through the SCR catalytic converter 9 arranged inside the reaction chamber 10. . The arrow 14 in FIG. 2 shows the flow of the exhaust gas passing through the exhaust gas aftertreatment system 3 when the bypass 12 is closed by the blocking element 13, and as is clear from FIG. The downstream end 15 leads to the reaction chamber 10 and the flow of the exhaust gas is redirected at an angle close to about 180 ° or 180 ° in the region of the downstream end 15 of the exhaust gas supply conduit 8, After the turn, it is guided through the SCR catalytic converter.

  The exhaust gas supply conduit 8 of the exhaust gas aftertreatment system 3 is provided with an introduction device 16 through which the exhaust gas flow, in particular in the region of the SCR catalytic converter 9, such as ammonia or ammonia precursors, exhaust gas. The reductant necessary to convert the nitrogen oxides as required can be introduced. The introduction device 16 of the exhaust gas aftertreatment system 3 is preferably an injection nozzle, through which ammonia or ammonia precursors are injected into the exhaust gas flow in the exhaust gas supply conduit 8. FIG. 2 shows the injection of the reducing agent into the exhaust gas stream in the region of the exhaust gas supply conduit 8 by means of the cone 17.

  The section of the exhaust gas aftertreatment system 3 that is located downstream of the introduction device 16 and upstream of the SCR catalytic converter 9 when viewed in the direction in which the exhaust gas flows is referred to as a mixing section. In particular, the exhaust gas supply conduit 8 provides a mixing section 18 downstream of the introduction device 16, in which exhaust gas can be mixed with a reducing agent upstream of the SCR catalytic converter 9.

  The exhaust gas supply conduit 8 communicates with the reaction chamber 10 at the downstream end 15. A baffle element 20 is disposed at the downstream end 15 of the exhaust gas supply conduit 8, and the baffle element is displaceable with respect to the downstream end 15 of the exhaust gas supply conduit 8. In the illustrated embodiment, the baffle element 20 is linearly displaceable with respect to the downstream end 15 of the exhaust gas supply conduit 8 leading to the reaction chamber 10. The baffle element 20 is displaceable relative to the downstream end 15 of the exhaust gas supply conduit 8 so that the exhaust gas supply conduit 8 is blocked at the downstream end 15 or is downstream 15. Is released. If the baffle element 20 is blocking the exhaust gas supply conduit 8 at the downstream end 15, preferably the blocking element 13 of the bypass 12 is opened, so that the exhaust gas is completely transferred to the SCR catalytic converter 9, or , Passing the side of the reaction chamber 10 that receives the SCR catalytic converter 9. If the baffle element 20 opens the downstream end 15 of the exhaust gas supply conduit 8, the blocking element 13 of the bypass 12 can be completely closed or at least partially open.

  When the baffle element 20 opens the downstream end 15 of the exhaust gas supply conduit 8, the relative position of the baffle element 20 with respect to the downstream end 15 of the exhaust gas supply conduit 8 is particularly the exhaust gas mass through the exhaust gas supply conduit 8. It depends on the flow rate and / or the exhaust gas temperature of the exhaust gas in the exhaust gas supply conduit 8 and / or the amount of reducing agent introduced into the exhaust gas stream through the introduction device 16.

  A further function of the baffle element 20 when the downstream end 15 of the exhaust gas supply conduit 8 is open is that when the liquid reducing agent droplets present in the exhaust gas stream reach the baffle element 20. Is to avoid the liquid reducing agent droplets from reaching the region of the SCR catalytic converter 9 by absorbing and spraying the droplets. Through the relative position of the baffle element 20 with respect to the downstream end 15 of the exhaust gas supply conduit 8 when the downstream end 15 is opened, in particular in the region of the downstream end 15 of the exhaust gas supply conduit 8. The direction of the exhaust gas is changed more strongly in the direction of the section located on the radially inner side of the SCR catalytic converter 9 or stronger in the direction of the section located on the radially outer side of the SCR catalytic converter 9. You can decide whether or not to do so.

  According to a preferred embodiment, the exhaust gas supply conduit 8 is widened in a funnel shape in the region of the downstream end 15 thereof to form a diffuser. Thereby, the flow cross section of the exhaust gas supply conduit 8 is enlarged in the region of the downstream end 15, and as is apparent from FIG. Upstream of section 15, it can be defined that its flow cross-section first decreases. That is, according to FIG. 2, the flow cross section of the exhaust gas supply conduit 8 is first substantially constant at the downstream of the reducing agent introduction device 16 as viewed in the flow direction of the exhaust gas, and then gradually becomes tapered, In the region of the downstream end 15, it is enlarged.

  In that case, the expansion of the flow cross section at the downstream end 15 of the exhaust gas supply conduit 8 is preferably shorter than the section of the exhaust gas supply conduit 8 where the exhaust gas supply conduit 8 is first tapered upstream of the downstream end 15. It is performed over the section.

  The baffle element 20 is preferably curved at the surface 22 facing the exhaust gas supply conduit 8, and is preferably curved in a bell shape, forming a flow path for the exhaust gas. The surface 22 of the baffle element 20 facing the downstream end 15 of the exhaust gas supply conduit 8 is radial with respect to the downstream end 15 of the exhaust gas supply conduit 8 in the radially inner portion of the baffle element 20. It has a shorter distance than the outer part. Accordingly, the baffle element 20 is retracted or curved in the center of the surface 24 in the direction of the downstream end 15 of the exhaust gas supply conduit 8 against the flow direction of the exhaust gas.

  As described above, the exhaust gas supply conduit 8 leads to the reaction chamber 10 that receives the SCR catalytic converter 9 at the downstream end 15 thereof. In that case, according to FIG. 2, the exhaust gas supply conduit 8 passes through the lower side 22 of the reaction chamber 10 and terminates at its downstream end 15 adjacent to the upper side 23 of the reaction chamber 10, At this time, as already described, the exhaust gas discharged from the exhaust gas supply conduit at the downstream end 15 changes the direction of 180 ° before flowing through the SCR catalytic converter 9.

  As is clear from FIG. 3, between the downstream end 15 of the exhaust gas supply conduit 8 and the SCR catalytic converter 9, an exhaust gas back pressure raising device 25 (device for increasing the exhaust gas back pressure) is connected to the SCR. Arranged upstream of the catalytic converter 9. The exhaust gas back pressure raising device 25 can be, for example, a lattice, a perforated plate, or the like. The exhaust gas back pressure raising device 25 is used upstream of the SCR catalytic converter 9, and the exhaust gas flow is blocked upstream of the SCR catalytic converter 9, so that the SCR catalytic converter 9 is evenly distributed in the circumferential direction and the radial direction. An exhaust gas stream can be supplied. Accordingly, the exhaust gas aftertreatment system can be downsized and the exhaust gas can be effectively purified.

  The exhaust gas back pressure raising device 25 further has an advantage that soot particles contained in the exhaust gas can be deposited. The soot particles that accumulate on the exhaust gas back pressure raising device 25 no longer reach the region of the SCR catalytic converter 9 and clog the SCR catalytic converter 9. This also makes it possible to ensure effective exhaust gas aftertreatment as well as downsizing the structure.

  The exhaust gas back pressure raising device 25 has a free flow section, which is at most twice, preferably at most 1 time, particularly preferably at most, the free flow section of the SCR catalytic converter 9. It corresponds to 0.5 times. Thereby, on the one hand, the equalization of the exhaust gas flow through the SCR catalytic converter 9 is ensured, on the other hand, soot particles have already accumulated in the region of the exhaust gas back pressure riser 25 and in the region of the SCR catalytic converter 9. It can be ensured that it is no longer reached.

  Preferably, the ratio of the thickness or length of the exhaust gas back pressure raising device 25 in the through-flow direction, ie, the exhaust gas flowing direction, to the thickness or length of the SCR catalytic converter 9 in the through-flow direction, ie, the exhaust gas flowing direction, is at least 1:50. , Preferably at least 1: 100, particularly preferably at least 1: 200. This also helps to realize effective exhaust gas aftertreatment in the exhaust gas aftertreatment system 3 having a downsized structure.

  Preferably, the distance between the exhaust gas back pressure raising device 25 and the SCR catalytic converter 9 corresponds to the distance in the flow direction, that is, the direction in which the exhaust gas flows, and the thickness of the SCR catalytic converter 9 in the flow direction, that is, the direction in which the exhaust gas flows. The ratio to the length is at most 1: 6, preferably at most 1: 5, particularly preferably at most 1: 4. This also makes it possible to ensure effective exhaust gas aftertreatment as well as downsizing the structure.

  As already mentioned, the exhaust gas back pressure raising device 15 is preferably a perforated plate or grid, preferably a relatively fine grid having a mesh width of in particular up to 6 mm, preferably up to 4 mm, particularly preferably up to 1.5 mm. It is.

  In the reaction chamber 10, the exhaust gas back pressure raising device 25 disposed between the downstream end of the exhaust gas supply conduit 8 and the SCR catalytic converter 9 may supply the exhaust gas to the SCR catalytic converter 9 evenly. Can be assured. The increase in exhaust gas back pressure blocks the exhaust gas flow, thereby ensuring an even distribution of exhaust gas across the SCR catalytic converter 9. As a result, the exhaust gas aftertreatment can be effectively performed with the downsizing of the structure.

  A further advantage of the exhaust gas back pressure raising device 25 is that it also functions as a prefilter capable of depositing soot particles contained in the exhaust gas. Thereby, it is possible to prevent the soot particles from reaching the SCR catalytic converter 9 and blocking the SCR catalytic converter 9 without being disturbed. This also enables effective exhaust gas aftertreatment along with downsizing of the structure.

  According to an advantageous further development of the invention, a reaction chamber in which an SCR catalytic converter 9 is received, an exhaust gas back pressure raising device 25 is received and the downstream end of the exhaust gas supply conduit 8 is in communication. 10, at least one blow device 24, for example, an air nozzle, is disposed, and one or each blow device 24 is disposed between the exhaust gas back pressure raising device 25 and the SCR catalytic converter 9. .

  In this case, one or each blowing device 24 is used for purging the exhaust gas back pressure raising device 25 and / or purging the SCR catalytic converter 9 with respect to the accumulated soot particles, whereby the SCR catalytic converter 9 And / or clogging of the exhaust gas back pressure raising device 25 is avoided. By arranging the blow device between the device 25 and the catalytic converter, the device can be purged against the flow direction of the exhaust gas.

  FIG. 4 shows a preferred orientation of one or each blowing device 24, preferably one or each blowing device 24 so that a vortex or swirl is formed inside the reaction chamber 10, ie Oriented on the surface of the exhaust gas back pressure raising device 25 that extends transversely to the flow-through direction or the flow direction of the exhaust gas and / or on the corresponding surface of the SCR catalytic converter 9. Yes. By such vortex flow or swirl flow, the soot particle purge from the SCR catalytic converter 9 and the exhaust gas back pressure raising device 25 can be performed particularly effectively. FIG. 4 shows that the reaction chamber 10 in which the SCR catalytic converter 9 and the exhaust gas back pressure raising device 25 are received has a wall 19 that is preferably circular in cross section, the wall 19 being the lower side of the reaction chamber 10. It shows that it extends between 22 and the upper side surface 23. By combining such a wall 27 with the orientation of one or each blowing device 24, a vortex or swirl flow can be formed particularly advantageously.

  The present invention enables effective exhaust gas after-treatment along with downsizing of the structure. For this purpose, the SCR catalytic converter 9 is received, and at least one exhaust gas back pressure raising device 25 is provided inside the reaction chamber 10 to which the downstream end 15 of the exhaust gas supply conduit 8 communicates. 9 is located upstream. By disposing at least one blow device 24 between the exhaust gas back pressure raising device 25 and the SCR catalytic converter 9, it is possible to further increase the efficiency of exhaust gas post-treatment, whereby the exhaust gas back pressure is increased. The ascending device 25 and / or the SCR catalytic converter 9 are purged with respect to the accumulated soot particles.

  In the internal combustion engine 1 of FIG. 1, the exhaust gas aftertreatment system 3 is arranged upright on the upper side of the exhaust gas turbocharger system 2. Access to the cylinders of the internal combustion engine 1 is free, but access to the exhaust gas turbochargers 4 and 5 is limited. However, the reaction chamber 10 can be easily disassembled when maintenance work is required in the exhaust gas turbochargers 4 and 6.

  Unlike the case where the exhaust gas aftertreatment system 3 as shown in FIG. 1 is arranged upright on the upper side of the exhaust gas turbocharger system 2, the exhaust gas aftertreatment system 3 is rotated by 90 ° to Although it is possible to arrange it horizontally beside the system 2, such a horizontal arrangement increases the length required for the arrangement. However, the internal combustion engine 1 and the exhaust gas turbocharger system 2 can be subjected to unlimited maintenance work without disassembling the reaction chamber 10.

The present invention is self-evidently applicable not only to SCR catalytic converters but also to CH ₄ and HCHO oxidation catalytic converters.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Exhaust gas turbocharger system 3 Exhaust gas aftertreatment system 4 Exhaust gas turbocharger 5 Exhaust gas turbocharger 6 High pressure turbine 7 Low pressure turbine 8 Exhaust gas supply conduit 9 SCR catalytic converter 10 Reaction chamber 11 Exhaust gas exhaust conduit 12 Bypass 13 Shut off element 14 Exhaust gas Guide 15 Downstream end 16 Introducing device 17 Injection cone 18 Mixing section 19 Wall 20 Baffle element 21 Conduit 22 Surface 23 Surface 24 Blow device 25 Device

Claims (17)

In an exhaust gas aftertreatment system (3) for an internal combustion engine comprising a catalytic converter (9) and an exhaust gas supply conduit (8) leading to the catalytic converter (9),
The exhaust gas supply conduit (8) leads to a reaction chamber (10) receiving the catalytic converter (9) at the downstream end (15),
An exhaust gas back pressure raising device (25) is provided inside the reaction chamber (10) and between the downstream end (15) of the exhaust gas supply conduit (8) and the catalytic converter (9). An exhaust gas aftertreatment system (3), which is arranged upstream of the catalytic converter (9).   The exhaust gas aftertreatment system (3) is configured as an SCR catalytic converter (9), and is arranged in an exhaust gas exhaust conduit (11) extending from the SCR catalytic converter (9) and the exhaust gas supply conduit (8). An introduction device (16) for introducing a reducing agent, in particular ammonia or an ammonia precursor, into the exhaust gas, and for mixing the exhaust gas with the reducing agent upstream of the SCR catalytic converter (9), 2. The exhaust gas aftertreatment system (3) according to claim 1, further comprising a mixing section (18) supplied downstream of the introduction device (16) by an exhaust gas supply conduit (8).   The exhaust gas back pressure raising device (25) has a free flow cross section, and the flow cross section corresponds to at most twice the free flow cross section of the catalytic converter (9). The exhaust gas aftertreatment system (3) according to claim 1 or 2.   The exhaust gas aftertreatment system according to claim 3, characterized in that the free flow cross section of the exhaust gas back pressure raising device (25) corresponds to a maximum of 1 time the free flow cross section of the catalytic converter (9). (3).   The exhaust after-gas exhaust according to claim 4, characterized in that the free flow cross section of the exhaust gas back pressure raising device (25) corresponds to at most 0.5 times the free flow cross section of the catalytic converter (9). Processing system (3).   The ratio of the thickness or length of the exhaust gas back pressure raising device (25) in the flow direction to the thickness or length of the catalytic converter (9) in the flow direction is at least 1:50. The exhaust gas aftertreatment system (3) according to any one of claims 1 to 5.   The exhaust gas according to claim 6, characterized in that the ratio of the thickness or length of the exhaust gas back pressure raising device (25) to the thickness or length of the catalytic converter (9) is at least 1: 100. Post-processing system (3).   The exhaust gas according to claim 7, characterized in that the ratio of the thickness or length of the exhaust gas back pressure raising device (25) to the thickness or length of the catalytic converter (9) is at least 1: 200. Post-processing system (3).   The ratio between the distance corresponding to the distance in the flow direction between the exhaust gas back pressure raising device (25) and the catalytic converter (9) and the thickness or length in the flow direction of the catalytic converter (9) is the maximum. The exhaust gas aftertreatment system (3) according to any one of claims 1 to 8, characterized in that the ratio is 2: 1.   The exhaust gas aftertreatment system (3) according to claim 9, characterized in that the ratio of the distance to the thickness or length of the catalytic converter (9) is at most 1: 1.   The exhaust gas aftertreatment system (3) according to claim 9, characterized in that the ratio of the distance to the thickness or length of the catalytic converter (9) is at most 1: 2.   The exhaust gas aftertreatment system (3) according to any one of claims 1 to 11, wherein the exhaust gas back pressure raising device (25) is configured as a lattice structure.   At least one blow device (24) is disposed inside the reaction chamber (10) and between the exhaust gas back pressure raising device (25) and the catalytic converter (9), the blow device being The exhaust gas aftertreatment system according to any one of claims 1 to 12, wherein the exhaust gas back pressure raising device (25) is purged and / or the catalytic converter (9) is purged. (3).   One or each blowing device (24) produces a vortex or swirl flow at the surface of the exhaust gas back pressure raising device (25) and / or the catalytic converter (9) that extends laterally with respect to the flow-through direction. 14. The exhaust gas aftertreatment system (3) according to claim 13, characterized in that it is oriented to form.   15. Internal combustion engine (1) having an exhaust gas aftertreatment system (3) according to any one of claims 1 to 14, characterized in particular by operating on diesel fuel or heavy oil fuel. (1).   The internal combustion engine (1) includes a first exhaust gas turbocharger (4) including a high pressure turbine (6) and a second exhaust gas turbocharger (5) including a low pressure turbine (7). 16. A system (2), wherein the exhaust gas aftertreatment system (3) is connected between the high pressure turbine (6) and the low pressure turbine (7). The internal combustion engine (1) described.   17. When the internal combustion engine (1) is a single-stage supercharging internal combustion engine, the exhaust gas aftertreatment system (3) is arranged upstream of the turbine. Internal combustion engine (1).