Apparatus for mixing exhaust gas flows

Abstract

The present invention relates to an apapratus (28) for mixing a plurality of exhaust gas flows for an exhaust gas system (10) of an internal combustion engine. The apparatus (28) has a first exhaust gas supply line (32), a second exhaust gas supply line (34), and an exhaust gas mixing chamber (36) into which the first exhaust gas supply line (32) and the second exhaust gas supply line (34) open. An exhaust gas discharge line (38) is connected to the exhaust gas mixing chamber (36) in order to discharge exhaust gas from the exhaust gas mixing chamber (36). An interfering body (40) is located in the exhaust gas mixing chamber (36). An exhaust gas sensor (46) is located on the exhaust gas discharge line (38).

Description

[0001] Device for mixing exhaust gas streams

[0002] Description

[0003] The invention relates to a device for mixing multiple exhaust gas streams. The invention further relates to an exhaust system comprising the device.

[0004] The use of SCR catalysts to reduce nitrogen oxides in exhaust gases is known. Exhaust systems, especially those of large internal combustion engines, can have multiple exhaust lines. The integration of SCR catalysts and / or other exhaust aftertreatment devices into a multi-line exhaust system can be complex in terms of design, control, and monitoring.

[0005] EP 1 908932 A2 relates to an exhaust system for diesel vehicles with a first and a second parallel branch, connectable to an engine on the exhaust side, wherein these parallel branches are connected to an SCR catalyst at their downstream ends. An injection device for the reducing agent is provided only on the first parallel branch. A mixing device is arranged upstream of the SCR catalyst, into which the parallel branches flow, and in which the exhaust stream containing the reducing agent from the first parallel branch is mixed with the exhaust stream free of the reducing agent from the second parallel branch.

[0006] EP 2 924 271 B1 discloses a homogenization device for at least two fluid streams for homogeneous gas-air mixing in a gas engine.

[0007] The invention is based on the object of creating an improved technology for monitoring exhaust gas in a multi-line exhaust system.

[0008] The problem is solved by the features of independent claim 1. Advantageous further developments are specified in the dependent claims and the description.

[0009] One aspect of the present disclosure relates to a device for mixing multiple (e.g., exactly two) exhaust gas streams for an (e.g., multi-strand, preferably double-strand) exhaust system of an internal combustion engine. The device comprises a first exhaust gas supply line, a second exhaust gas supply line, and an exhaust gas mixing chamber into which the first exhaust gas supply line and the second exhaust gas supply line open, preferably on opposite sides of the exhaust gas mixing chamber. The device comprises one, preferably single, exhaust gas discharge line, which is connected to the exhaust gas mixing chamber for discharging exhaust gas from the exhaust gas mixing chamber, and a (e.g., flow) disruptor arranged in the exhaust gas mixing chamber. The device further comprises an exhaust gas sensor arranged on the exhaust gas discharge line (e.g., projecting into the exhaust gas discharge line).

[0010] Advantageously, the device can enable exhaust gas from multiple exhaust systems to be monitored jointly by the exhaust gas sensor. This preferably makes it unnecessary to monitor the multiple exhaust systems separately with their own exhaust gas sensors. The average value detected by the exhaust gas sensor can in fact already make it possible to make statements about the functionality of any exhaust gas aftertreatment devices present in the individual exhaust systems. For example, a malfunction of an exhaust gas aftertreatment system in just one of the multiple exhaust systems can change the average value detected by the exhaust gas sensor to such an extent that the malfunction can be detected. The obstruction body can play a special role, as it supports the measurement of the most representative average value possible using the exhaust gas sensor, or can even make this possible in the first place.The disruptive body in the exhaust gas mixing chamber can significantly improve the mixing of the exhaust gas streams flowing separately through the first and second exhaust gas supply lines by extending the residence time within the exhaust gas mixing chamber and generating turbulence within the exhaust gas mixing chamber. This can preferably reduce any existing concentration gradients. At the outlet from the exhaust gas mixing chamber, the substance components contained in the exhaust gas, e.g., NOx and / or NH3, can thus be distributed essentially evenly across the flow cross-section. Advantageously, a particularly well-mixed, combined exhaust gas stream from the first and second exhaust gas streams can thus be fed to the exhaust gas sensor, whereby the measurement by the exhaust gas sensor produces a representative average value for the two exhaust gas streams. The average value can, for example, relate to an average exhaust gas concentration and / or temperature.This can advantageously enable, for example, simple and reliable monitoring of a multi-line exhaust system.

[0011] In one embodiment, the exhaust gas discharge line extends into the exhaust gas mixing chamber, preferably toward a center point or central axis of the exhaust gas mixing chamber. Advantageously, the region of the exhaust gas mixing chamber that extends into the exhaust gas mixing chamber can thus (also) improve the mixing of the exhaust gases in the mixing chamber by extending the residence time, etc.

[0012] In a further embodiment, the baffle forms an inlet area of ​​the exhaust gas discharge line, preferably extending into the exhaust gas mixing chamber. This advantageously enables a particularly effective yet simple baffle.

[0013] In one embodiment, the baffle and the exhaust gas discharge line are formed integrally with each other. This advantageously simplifies design and assembly.

[0014] In a further embodiment, the baffle is tubular, cylindrical, or funnel-shaped. Alternatively or additionally, the baffle can be designed to allow exhaust gas to flow through. Alternatively or additionally, the baffle can be aligned coaxially with the exhaust gas discharge line.

[0015] In a further embodiment, a circumferential surface of the bluff body is free of inlets and / or passages. Alternatively or additionally, the bluff body can have an inlet, preferably only on the front side, for flow into the bluff body. This advantageously allows the exhaust gas to be deflected on the outside of the circumferential surface to flow around the bluff body. Alternatively or additionally, the exhaust gas can be deflected to flow into the front-side inlet of the bluff body. This advantageously improves mixing within the exhaust gas mixing chamber.

[0016] For example, the disruptive body may have one, preferably single, outlet for flowing out of the disruptive body on a side opposite to the inlet of the disruptive body.

[0017] In one embodiment, the disruptive body has a longitudinal extension relative to a longitudinal axis of the exhaust mixing chamber and / or the exhaust gas discharge line. An (exhaust mixing chamber) outlet opening of the first exhaust gas supply line has a longitudinal extension relative to the longitudinal axis. An (exhaust mixing chamber) outlet opening of the second exhaust gas supply line has a longitudinal extension relative to the longitudinal axis. The longitudinal extension of the disruptive body is greater than or equal to the longitudinal extension of the outlet opening of the first and / or second exhaust gas supply line. The disruptive body can thus advantageously be dimensioned such that it can ensure significantly longer exhaust gas paths and thus a significantly longer exhaust gas residence time in the exhaust mixing chamber to improve mixing.

[0018] In a further embodiment, the disruptive body overlaps, preferably completely, with an (exhaust gas mixing chamber) outlet opening of the first exhaust gas supply line, with respect to a radial direction of the exhaust gas mixing chamber. Alternatively or additionally, the disruptive body can overlap, preferably completely, with an (exhaust gas mixing chamber) outlet opening of the second exhaust gas supply line, with respect to a (e.g., further) radial direction of the exhaust gas mixing chamber. This advantageously allows the disruptive body to divert the exhaust gas flows flowing in from the outlet openings in the exhaust gas mixing chamber to improve mixing before the exhaust gas leaves the exhaust gas mixing chamber through the exhaust gas discharge line.

[0019] In one embodiment, the disruptive body is designed such that it: extends an exhaust gas path from the first exhaust gas supply line through the exhaust gas mixing chamber to the exhaust gas discharge line and / or extends an exhaust gas path from the second exhaust gas supply line through the exhaust gas mixing chamber to the exhaust gas discharge line; and / or extends a residence time of exhaust gas from the first exhaust gas supply line in the exhaust gas mixing chamber and / or extends a residence time of exhaust gas from the second exhaust gas supply line in the exhaust gas mixing chamber; and / or promotes a mixing of exhaust gas from the first exhaust gas supply line and exhaust gas from the second exhaust gas supply line in the exhaust gas mixing chamber; and / or obstructs a direct flow connection from the first exhaust gas supply line through the exhaust gas mixing chamber to the exhaust gas discharge line and / or obstructs a direct flow connection from the second exhaust gas supply line through the exhaust gas mixing chamber to the exhaust gas discharge line.

[0020] In a further embodiment, the exhaust gas discharge line has a Venturi tube section. Advantageously, the Venturi tube section can assist the exhaust gas flow out of the exhaust gas mixing chamber and reduce pressure loss in the device.

[0021] In one embodiment, the exhaust gas sensor is arranged at a venturi constriction of the venturi tube section, preferably extending into the venturi tube section. The venturi tube section can enhance the mixing / homogenization of the exhaust gas. Particularly good mixing can result when flowing through the venturi constriction, whereby the measurement of the exhaust gas sensor arranged there can yield a particularly representative average value for exhaust gas from the first and second exhaust gas supply line. In a further embodiment, the disruptive body is a partial section of the venturi tube section. The disruptive body can thus advantageously support the mixing of the exhaust gas both from the outside and from the inside. Furthermore, the venturi tube section can be designed in a particularly space-efficient manner in this way.

[0022] In one embodiment, the exhaust gas sensor is designed to detect an exhaust gas component. Alternatively or additionally, the exhaust gas sensor can be a nitrogen oxide or ammonia sensor. Alternatively or additionally, the exhaust gas sensor can be a temperature sensor. Alternatively or additionally, the exhaust gas sensor can be arranged directly downstream of the obstruction and / or the exhaust gas mixing chamber.

[0023] In a further embodiment, the exhaust gas mixing chamber is substantially spherical. Alternatively, the exhaust gas mixing chamber can be substantially cylindrical. Alternatively, the exhaust gas mixing chamber can have a substantially S-shaped cross section, with the first exhaust gas supply line and the second exhaust gas supply line preferably being arranged at opposite ends of the S-shape. Advantageously, the shape of the exhaust gas mixing chamber can thus be adapted to the course of the exhaust gas supply lines and to improve the exhaust gas mixture.

[0024] In one embodiment, the first exhaust gas supply line opens substantially tangentially into the exhaust gas mixing chamber. Alternatively or additionally, the second exhaust gas supply line opens substantially tangentially into the exhaust gas mixing chamber. Alternatively or additionally, the first exhaust gas supply line and the second exhaust gas supply line are arranged substantially parallel to one another. Alternatively or additionally, the first exhaust gas supply line and / or the second exhaust gas supply line is / are arranged substantially transversely or substantially parallel to the exhaust gas discharge line.

[0025] A further aspect of the present disclosure relates to an (e.g., double-line) exhaust system for an internal combustion engine. The exhaust system comprises a first exhaust line with a first exhaust aftertreatment device, preferably with a first SCR catalyst, and a second exhaust line with a second exhaust aftertreatment device, preferably with a second SCR catalyst. The exhaust system further comprises a device as disclosed herein. Preferably, the first exhaust gas supply line can be arranged (e.g., directly) downstream of the first exhaust aftertreatment device (e.g., the first SCR catalyst), and / or the second exhaust gas supply line can be arranged (e.g., directly) downstream of the second exhaust aftertreatment device (e.g., the second SCR catalyst). Advantageously, the exhaust system can achieve the same advantages that have already been described with reference to the device.

[0026] In one exemplary embodiment, the exhaust system further comprises a diagnostic device configured to detect a malfunction in exhaust gas aftertreatment by means of the first and second exhaust gas aftertreatment devices based on a signal from the exhaust gas sensor and preferably to issue a warning if the malfunction is detected. Advantageously, multiple exhaust gas aftertreatment devices of multiple exhaust tracts can thus be monitored for malfunctions using the diagnostic device and a single exhaust gas sensor.

[0027] Preferably, the term "diagnostic device" can refer to electronics (e.g., with microprocessors and data storage) that, depending on its design, can perform control and / or regulation tasks and / or processing tasks. Even if the term "control" is used herein, it can also appropriately include or mean "regulation" or "control with feedback" and / or "processing."

[0028] A further aspect of the present disclosure relates to a vehicle, such as a watercraft, motor vehicle, preferably a commercial vehicle, particularly preferably a truck or bus, or a stationary installation. The vehicle or stationary installation comprises a device as disclosed herein or an exhaust system as disclosed herein.

[0029] The above-described preferred embodiments and features of the invention can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings. They show:

[0030] Figure 1 is a schematic representation of an exhaust system according to an embodiment of the present disclosure;

[0031] Figure 2 is a perspective view of an apparatus for mixing exhaust gas streams according to an embodiment of the present disclosure;

[0032] Figure 3 is a sectional view taken along a line AA in Figure 4;

[0033] Figure 4 is a side view of the exemplary device of Figure 2;

[0034] Figure 5 shows the side view of Figure 4 with schematically illustrated exhaust gas streams; Figure 6 shows a perspective view of a device for mixing exhaust gas streams according to a further embodiment of the present disclosure;

[0035] Figure 7 is a sectional view taken along a line BB in Figure 8;

[0036] Figure 8 is a side view of the exemplary device of Figure 6;

[0037] Figure 9 shows the side view of Figure 8 with schematically illustrated exhaust gas flows;

[0038] Figure 10 is a perspective view of an apparatus for mixing exhaust gas streams according to another embodiment of the present disclosure;

[0039] Figure 11 is a sectional view taken along a line CC in Figure 12;

[0040] Figure 12 is a side view of the exemplary device of Figure 10; and

[0041] Figure 13 shows the side view of Figure 12 with schematically illustrated exhaust gas flows.

[0042] The embodiments shown in the figures correspond at least partially, so that similar or identical parts are provided with the same reference numerals and for their explanation reference is also made to the description of the other embodiments or figures in order to avoid repetition.

[0043] Figure 1 shows an exhaust system 10 for an internal combustion engine. The exhaust system 10 can receive and treat exhaust gas generated by the internal combustion engine, e.g., to reduce nitrogen oxides in the exhaust gas. The internal combustion engine can be embodied, for example, as a diesel internal combustion engine. The internal combustion engine can be incorporated, for example, in a motor vehicle (e.g., a commercial vehicle such as a truck or bus), a watercraft (e.g., a ship), or a stationary facility (e.g., a power plant).

[0044] The exhaust system 10 comprises a first exhaust line 12, a second exhaust line 14, and a device 28 for mixing multiple exhaust gas streams. Optionally, the exhaust system 10 may further comprise a diagnostic device 30.

[0045] The first exhaust system 12 and the second exhaust system 14 can be connected in parallel. The first exhaust system 12 and the second exhaust system 14 can, for example, run in parallel. It is possible for the first exhaust system 12 and the second exhaust system 14 to be arranged downstream of a common exhaust manifold (e.g., exhaust manifold). Alternatively, for example, the first exhaust system 12 can be arranged downstream of a first exhaust manifold (e.g., first exhaust manifold) and the second exhaust system 14 can be arranged downstream of a second exhaust manifold (e.g., second exhaust manifold).

[0046] The first exhaust system 12 and the second exhaust system 14 each have an exhaust aftertreatment device 16, 18. The exhaust aftertreatment devices 16, 18 can be configured, for example, to reduce nitrogen oxides in the exhaust gas by means of selective catalytic reduction, to remove or filter particles or soot from the exhaust gas, and / or to treat the exhaust gas in another way, preferably to purify it.

[0047] Preferably, the exhaust gas aftertreatment devices may each have an additive dosing element 20, 22 and / or an SCR catalyst 24, 26.

[0048] The first additive metering element 20 can be arranged in the first exhaust system 12. The first additive metering element 20 can be arranged upstream of the first SCR catalyst 24. The first additive metering element 20 can meter an additive into the first exhaust system 12. For example, the first additive metering element 20 can inject or spray the additive into the first exhaust system 12. The additive is preferably a reducing agent, particularly preferably an aqueous urea solution. The metered-in additive can mix with a first exhaust gas stream flowing through the first exhaust system 12. Thermolysis and hydrolysis of the additive can occur.

[0049] The second additive metering element 22 can be arranged in the second exhaust system 14. The second additive metering element 22 can be arranged upstream of the second SCR catalyst 26. The second additive metering element 22 can meter an additive into the second exhaust system 14. For example, the second additive metering element 22 can inject or spray the additive into the second exhaust system 14. The additive is preferably a reducing agent, particularly preferably an aqueous urea solution. The metered-in additive can mix with a second exhaust stream flowing through the second exhaust system 14. Thermolysis and hydrolysis of the additive can occur.

[0050] The first SCR catalyst 24 may be arranged in the first exhaust system 12. The first SCR catalyst 24 may be arranged downstream of the first additive dosing element 20. The first SCR catalyst 24 may reduce nitrogen oxides in the first exhaust stream flowing through the first exhaust system 12.

[0051] The second SCR catalyst 26 may be arranged in the second exhaust system 14. The second SCR catalyst 26 may be arranged downstream of the second additive dosing element 22. The second SCR catalyst 26 may reduce nitrogen oxides in the second exhaust stream flowing through the second exhaust system 14.

[0052] In the device 28, a plurality of exhaust gas streams are mixed together. Particularly preferably, the device 28 can be arranged as shown in Figure 1, namely downstream of the first exhaust line 12 and the second exhaust line 14. The device 28 can receive the first exhaust gas stream from the first exhaust line 12 and the second exhaust gas stream from the second exhaust line 14 and mix them together. However, it is also conceivable, for example, for the device 28 to be arranged differently for mixing a plurality of exhaust gas streams or to be included in a differently configured exhaust system.

[0053] The diagnostic device 30 can receive a signal from an exhaust gas sensor 46 of the device 28. The exhaust gas sensor 46 is configured to detect a parameter / property of the exhaust gas. The exhaust gas sensor 46 can be arranged in the device 28 such that the parameter / property is detected from the multiple exhaust gas streams already mixed together in the device 28.

[0054] The exhaust gas sensor 46 is particularly preferably designed to detect an exhaust gas component of the exhaust gas. The exhaust gas sensor 46 can be, for example, a nitrogen oxide or ammonia sensor. A signal from the exhaust gas sensor 46 can, for example, indicate whether the respective exhaust gas component was detected and / or the concentration of the respective exhaust gas component and / or the quantity of the respective exhaust gas component.

[0055] Alternatively or additionally, the exhaust gas sensor 46 can be, for example, a temperature sensor for measuring the temperature of the exhaust gas. A signal from the exhaust gas sensor 46 can, for example, indicate a measured exhaust gas temperature.

[0056] Based on the received signal, the diagnostic device 30 can detect whether at least one of the two exhaust aftertreatment devices 16, 18 is malfunctioning. This may be the case, for example, if the signal indicates a concentration of the detected exhaust gas component and / or quantity of the detected exhaust gas component and / or a detected temperature, etc., that deviates from a predeterminable tolerance range, e.g., is greater than, less than, or equal to a predeterminable limit value.

[0057] Preferably, the diagnostic device 30 can issue a warning if the malfunction is detected. The warning can, for example, comprise a warning signal sent to a control unit of the exhaust system 10 and / or the internal combustion engine. The warning can, for example, have a visual, acoustic, and / or haptic output via a user interface.

[0058] Figures 2 to 5 show an exemplary device 28.

[0059] The device 28 has a first exhaust gas supply line 32, a second exhaust gas supply line 34, an exhaust gas mixing chamber 36, an exhaust gas discharge line 38, a disturbance body 40 and the exhaust gas sensor 46.

[0060] The first exhaust gas supply line 32 can preferably form a downstream end of the first exhaust system 12 (see Figure 1). The first exhaust gas supply line 32 can be arranged downstream of the first SCR catalyst 24. The second exhaust gas supply line 34 can preferably form a downstream end of the second exhaust system 14 (see Figure 1). The second exhaust gas supply line 34 can be arranged downstream of the second SCR catalyst 26.

[0061] The first and second exhaust gas supply lines 32, 34 open into the exhaust gas mixing chamber 36. It is possible for at least one additional exhaust gas supply line to open into the exhaust gas mixing chamber 36 (not shown in the figures). However, the first and second exhaust gas supply lines 32, 34 are preferably the only exhaust gas supply lines that open into the exhaust gas mixing chamber 36.

[0062] Preferably, the first and second exhaust gas supply lines 32, 34 can open into the exhaust gas mixing chamber 36 on opposite sides of the exhaust gas mixing chamber 36. The outlet opening of the first and / or second exhaust gas supply lines 32, 34 can extend along the entire length of the exhaust gas mixing chamber 36 or only along a portion thereof. The outlet opening of the first and / or second exhaust gas supply lines 32, 34 can preferably be arranged in an outer wall of the exhaust gas mixing chamber 36, preferably as a through-opening in the outer wall. The first and second exhaust gas supply lines 32, 34 can be arranged substantially parallel to one another. For example, a longitudinal axis of the first exhaust gas supply line 32 can be parallel to a longitudinal axis of the second exhaust gas supply line 34.

[0063] The first and second exhaust gas supply lines 32, 34 may preferably extend from the same direction towards the exhaust gas mixing chamber 36.

[0064] The first exhaust gas supply line 32 and / or the second exhaust gas supply line 34 can be arranged substantially parallel to the exhaust gas discharge line 38. For example, a longitudinal axis of the first and / or second exhaust gas supply line 32, 34 can be parallel to a longitudinal axis of the exhaust gas discharge line 38 and / or the exhaust gas mixing chamber 36. It is also possible for the longitudinal axis of the first and / or second exhaust gas supply line 32, 34 to run at an angle to the longitudinal axis of the exhaust gas discharge line 38 and / or the exhaust gas mixing chamber 36, e.g., at an acute angle or a right angle (not shown in Figures 2 to 5).

[0065] The exhaust gas mixing chamber 36 is designed to mix the received exhaust gas streams. In the exhaust gas mixing chamber 36, the first exhaust gas stream received from the first exhaust gas supply line 32 and the second exhaust gas stream received from the second exhaust gas supply line 34 can be mixed with one another.

[0066] The exhaust gas mixing chamber 36 can, for example, essentially have a three-dimensional (curved) S-shape, as shown by way of example in Figure 2. The exhaust gas mixing chamber 36 can have a cross-section in a (curved) S-shape. The S-shaped cross-section can lie in a plane that is arranged perpendicular to a longitudinal axis of the first exhaust gas supply line 32, perpendicular to a longitudinal axis of the second exhaust gas supply line 34, perpendicular to a longitudinal axis of the exhaust gas mixing chamber 36, and / or perpendicular to a longitudinal axis of the exhaust gas discharge line 38.

[0067] The first exhaust gas supply line 32 and the second exhaust gas supply line 34 can be arranged at opposite ends of the S-shape. A main chamber region of the exhaust gas mixing chamber 36 can be arranged in a central section of the S-shape. The main chamber region can be arranged between the first exhaust gas supply line 32 and the second exhaust gas supply line 34. The exhaust gas discharge line 38 is connected, preferably directly, to the exhaust gas mixing chamber 36 for discharging exhaust gas from the exhaust gas mixing chamber 36. Preferably, the exhaust gas discharge line 38 is the only exhaust gas discharge line connected to the exhaust gas mixing chamber 36. Exhaust gas from the exhaust gas mixing chamber 36 can flow directly into the exhaust gas discharge line 38.

[0068] Preferably, the exhaust gas discharge line 38 can extend into the exhaust gas mixing chamber 36. For example, the exhaust gas discharge line 38 can extend into the exhaust gas mixing chamber 36 up to a center point or beyond, e.g., along a center axis of the exhaust gas mixing chamber 36.

[0069] Particularly preferably, the exhaust gas discharge line 38 has a Venturi tube section 42. The Venturi tube section 42 can have a Venturi constriction 44. On both sides of the Venturi constriction 44, the Venturi tube section 42 can widen in a funnel shape. At the Venturi constriction 44, the Venturi tube section 42 can have its smallest flow cross-section.

[0070] The disruptive body 40 is arranged in the exhaust gas mixing chamber 36, preferably coaxially aligned with the exhaust gas discharge line 38. Preferably, with respect to a longitudinal axis of the exhaust gas mixing chamber 36, a longitudinal extent of the disruptive body 40 can be greater than or equal to one half of a longitudinal extent of the exhaust gas mixing chamber 36.

[0071] The disruptive body 40 is preferably tubular. For example, the disruptive body can be (hollow) cylindrical or funnel-shaped.

[0072] Preferably, the bluff body 40 can be permeable to exhaust gas. The bluff body 40 can, for example, have an internal channel for the exhaust gas to flow through. The bluff body 40 can have an inlet on its front side for flow into the bluff body 40 or into the internal channel of the bluff body 40. For example, the inlet can be arranged in the region of a center point or a central axis of the exhaust gas mixing chamber 36. A jacket or peripheral surface of the bluff body 40, however, can be free of inlets and / or passages leading to the internal channel.

[0073] The disruptive body 40 can preferably form an inlet region of the exhaust gas discharge line 38 that projects into the exhaust gas mixing chamber 36. For example, the disruptive body 40 and the exhaust gas discharge line 38 can be formed integrally with one another. The disruptive body 40 can, for example, project into the region of a center point of the exhaust gas mixing chamber 36 or beyond, e.g., along a center axis of the exhaust gas mixing chamber 36.

[0074] Preferably, the disruptive body 40 can be a partial section of the Venturi tube section 42. Particularly preferably, the partial section can be funnel-shaped. The partial section can taper in a funnel shape toward the Venturi constriction 44.

[0075] The baffle 40 can also be referred to as a flow baffle. The baffle 40 can promote mixing of exhaust gas (first exhaust stream) from the first exhaust supply line 32 and exhaust gas (second exhaust stream) from the second exhaust supply line 34 in the exhaust mixing chamber 36. The baffle 40 thus has the function of improving exhaust mixing or homogenization in the exhaust mixing chamber 36. The baffle 40 can achieve this mixing-support function in several combinable ways.

[0076] For example, the obstructing body 40 can obstruct or disrupt a direct flow connection from an outlet opening of the first exhaust gas supply line 32 through the exhaust gas mixing chamber 36 to the exhaust gas discharge line 38. Alternatively or additionally, the obstructing body 40 can obstruct a direct (further) flow connection from an outlet opening of the second exhaust gas supply line 34 through the exhaust gas mixing chamber 36 to the exhaust gas discharge line 38.

[0077] For example, the disruptive body 40 can extend an exhaust path of the first exhaust gas flow from the first exhaust gas supply line 32 through the exhaust gas mixing chamber 36 to the exhaust gas discharge line 38, as is outlined, for example, in Figure 5 by the first exhaust gas flow shown in dotted lines (see also Figures 9 and 13 for the other exemplary embodiments). Alternatively or additionally, the disruptive body 40 can extend an exhaust path of the second exhaust gas flow from the second exhaust gas supply line 34 through the exhaust gas mixing chamber 36 to the exhaust gas discharge line 38, as is also outlined in Figure 5 by the second exhaust gas flow shown in dashed lines (see also Figures 9 and 13 for the other exemplary embodiments).

[0078] For example, the disruptive body 40 can extend the residence time of exhaust gas (first exhaust stream) from the first exhaust supply line 32 and / or of exhaust gas (second exhaust stream) from the second exhaust supply line 34 in the exhaust mixing chamber 36. The exhaust sensor 46 is arranged on the exhaust discharge line 38. Preferably, the exhaust sensor 46 is arranged directly downstream of the exhaust mixing chamber 36 and / or the disruptive body 40. Preferably, the exhaust sensor 46 is arranged on the Venturi constriction 44, preferably projecting into the Venturi tube section 42.

[0079] It is possible for at least one additional exhaust gas sensor (not shown in Figures 1 to 12) to be arranged on the exhaust gas discharge line 38. For example, the additional exhaust gas sensor can detect a different property / parameter of the exhaust gas than the exhaust gas sensor 46. Preferably, the additional exhaust gas sensor can be a temperature sensor. The additional exhaust gas sensor is preferably arranged downstream of the exhaust gas sensor 46.

[0080] Figures 6 to 9 show another exemplary device 28', and Figures 10 to 13 show another exemplary device 28". The device 28' of Figures 6 to 9 and the device 28" of Figures 10 to 13 are modified compared to the device 28 of Figures 2 to 5, as described below.

[0081] The first and second exhaust gas supply lines 32, 34 can open essentially tangentially into the exhaust gas mixing chamber 36.

[0082] The first exhaust gas supply line 32 and / or the second exhaust gas supply line 34 can be arranged substantially transversely to the exhaust gas discharge line 38. For example, a longitudinal axis of the first and / or second exhaust gas supply line 32, 34 can be arranged transversely to a longitudinal axis of the exhaust gas discharge line 38 and / or the exhaust gas mixing chamber 36.

[0083] The first and second exhaust gas supply lines 32, 34 may preferably extend from opposite directions towards the exhaust gas mixing chamber 36.

[0084] The exhaust gas mixing chamber 36 of the device 28' can be substantially cylindrical, particularly preferably circular cylindrical, as shown in Figures 6 to 9.

[0085] The exhaust gas mixing chamber 36 of the device 28" may be substantially spherical, as shown in Figures 10 to 13.

[0086] Relative to a longitudinal axis of the exhaust gas mixing chamber 36, a longitudinal extent of the disruptive body 40 can preferably be greater than or equal to a longitudinal extent of an outlet opening of the first exhaust gas supply line 32 and / or a longitudinal extent of an outlet opening of the second exhaust gas supply line 34. The disruptive body 40 can, viewed with respect to a radial direction of the exhaust gas mixing chamber 36, overlap with an outlet opening of the first exhaust gas supply line 32 or cover it, preferably completely. Viewed with respect to a further radial direction of the exhaust gas mixing chamber 36, the disruptive body 40 can overlap with an outlet opening of the second exhaust gas supply line 34 or cover it, preferably completely. The radial direction and the further radial direction can emanate from a central axis or a center point of the exhaust gas mixing chamber 36, e.g., in opposite directions.

[0087] The invention is not limited to the preferred embodiments described above. Rather, numerous variants and modifications are possible that also utilize the inventive concept and therefore fall within the scope of protection.

[0088] In particular, the invention also claims protection for the subject matter and features of the subclaims, independent of the referenced claims. In particular, the individual features of independent claim 1 are each disclosed independently of one another. Additionally, the features of the subclaims are also disclosed independently of all features of independent claim 1 and, for example, independently of the features relating to the presence and / or configuration of the first exhaust gas supply line, the second exhaust gas supply line, the exhaust gas mixing chamber, the exhaust gas discharge line, the disruptive body, and / or the exhaust gas sensor of independent claim 1.

[0089] List of reference symbols

[0090] 10 Exhaust system

[0091] 12 First exhaust system

[0092] 14 Second exhaust system

[0093] 16 First exhaust aftertreatment device

[0094] 18 Second exhaust aftertreatment system

[0095] 20 First additive dosing element

[0096] 22 Second additive dosing element

[0097] 24 First SCR catalyst

[0098] 26 Second SCR catalyst

[0099] 28 Device for mixing several exhaust gas streams

[0100] 30 Diagnostic device

[0101] 32 First exhaust gas supply line

[0102] 34 Second exhaust gas supply line

[0103] 36 Exhaust gas mixing chamber

[0104] 38 Exhaust gas discharge line

[0105] 40 disruptive bodies

[0106] 42 Venturi tube section

[0107] 44 Venturi constriction

[0108] 46 exhaust gas sensor

Claims

Patent claims 1. A device (28) for mixing a plurality of exhaust gas streams for an exhaust system (10) of an internal combustion engine, the device (28) comprising: a first exhaust gas supply line (32); a second exhaust gas supply line (34); an exhaust gas mixing chamber (36) into which the first exhaust gas supply line (32) and the second exhaust gas supply line (34) open, preferably on opposite sides of the exhaust gas mixing chamber (36); a preferably single exhaust gas discharge line (38) which is connected to the exhaust gas mixing chamber (36) for discharging exhaust gas from the exhaust gas mixing chamber (36); a disruptive body (40) which is arranged in the exhaust gas mixing chamber (36); and an exhaust gas sensor (46) which is arranged on the exhaust gas discharge line (38).

2. Device (28) according to claim 1, wherein: the exhaust gas discharge line (38) projects into the exhaust gas mixing chamber (36), preferably towards a center point or a central axis of the exhaust gas mixing chamber (36).

3. Device (28) according to claim 1 or claim 2, wherein: the disruptive body (40) forms an inlet region of the exhaust gas discharge line (38), preferably projecting into the exhaust gas mixing chamber (36); and / or the disruptive body (40) and the exhaust gas discharge line (38) are formed integrally with one another.

4. Device (28) according to one of the preceding claims, wherein: the disruptive body (40) is tubular, cylindrical, or funnel-shaped; and / or the disruptive body (40) is designed for exhaust gas to flow through; and / or the disruptive body (40) is aligned coaxially with the exhaust gas discharge line (38).

5. Device (28) according to one of the preceding claims, wherein: a lateral surface of the disruptive body (40) is free of inlets and / or passages; and / or the disruptive body (40) has, preferably only, an inlet on the front side for flow into the disruptive body (40).

6. Device (28) according to one of the preceding claims, wherein: the disruptive body (40) has a longitudinal extension relative to a longitudinal axis of the exhaust gas mixing chamber (36) and / or the exhaust gas discharge line (38); an orifice of the first exhaust gas supply line (32) has a longitudinal extension relative to the longitudinal axis; an orifice of the second exhaust gas supply line (34) has a longitudinal extension relative to the longitudinal axis; and the longitudinal extension of the disruptive body (40) is greater than or equal to the longitudinal extension of the orifice of the first and / or second exhaust gas supply line (32, 34).

7. Device (28) according to one of the preceding claims, wherein: the disruptive body (40) overlaps, preferably completely, with an orifice of the first exhaust gas supply line (32) with respect to a radial direction of the exhaust gas mixing chamber (36); and / or the disruptive body (40) overlaps, preferably completely, with an orifice of the second exhaust gas supply line (34) with respect to a radial direction of the exhaust gas mixing chamber (36).

8. Device (28) according to one of the preceding claims, wherein the disruptive body (40) is designed such that it: extends an exhaust gas path from the first exhaust gas supply line (32) through the exhaust gas mixing chamber (36) to the exhaust gas discharge line (38) and / or extends an exhaust gas path from the second exhaust gas supply line (34) through the exhaust gas mixing chamber (36) to the exhaust gas discharge line (38); and / or extends a residence time of exhaust gas from the first exhaust gas supply line (32) in the exhaust gas mixing chamber (36) and / or extends a residence time of exhaust gas from the second exhaust gas supply line (34) in the exhaust gas mixing chamber (36); and / or promotes a mixing of exhaust gas from the first exhaust gas supply line (32) and exhaust gas from the second exhaust gas supply line (34) in the exhaust gas mixing chamber (36);and / or a direct flow connection from the first exhaust gas supply line (32) through the exhaust gas mixing chamber (36) to the exhaust gas discharge line (38) is obstructed and / or a direct flow connection from the second exhaust gas supply line (34) through the exhaust gas mixing chamber (36) to the exhaust gas discharge line (38) is obstructed.; 9. Device (28) according to one of the preceding claims, wherein: the exhaust gas discharge line (38) has a venturi tube section.

10. The device (28) according to claim 9, wherein: the exhaust gas sensor (46) is arranged on a venturi constriction (44) of the venturi tube section (42), preferably projecting into the venturi tube section (42); and / or the disruptive body (40) is a partial section of the venturi tube section (42).

11. Device (28) according to one of the preceding claims, wherein: the exhaust gas sensor (46) is designed to detect an exhaust gas component; and / or the exhaust gas sensor (46) is a nitrogen oxide or ammonia sensor; and / or the exhaust gas sensor (46) is a temperature sensor; and / or the exhaust gas sensor (46) is arranged directly downstream of the disturbance body (40) and / or the exhaust gas mixing chamber (36).

12. Device (28) according to one of the preceding claims, wherein: the exhaust gas mixing chamber (36) is substantially spherical; or the exhaust gas mixing chamber (36) is substantially cylindrical; or the exhaust gas mixing chamber (36) has a cross-section substantially in an S-shape, wherein the first exhaust gas supply line (32) and the second exhaust gas supply line (34) are arranged at opposite ends of the S-shape.

13. Device (28) according to one of the preceding claims, wherein at least one of the following is fulfilled: the first exhaust gas supply line (32) opens substantially tangentially into the exhaust gas mixing chamber (36); the second exhaust gas supply line (34) opens substantially tangentially into the exhaust gas mixing chamber (36); the first exhaust gas supply line (32) and the second exhaust gas supply line (34) are arranged substantially parallel to one another; and the first exhaust gas supply line (32) and / or the second exhaust gas supply line (34) is / are arranged substantially transversely or substantially parallel to the exhaust gas discharge line (38).

14. An exhaust system (10) for an internal combustion engine, the exhaust system (10) comprising: a first exhaust tract (12) with a first exhaust aftertreatment device (16), preferably with a first SCR catalyst (24); a second exhaust tract (14) with a second exhaust aftertreatment device (18), preferably with a second SCR catalyst (26); and a device (28) according to one of the preceding claims, wherein the first exhaust gas supply line (32) is arranged downstream of the first exhaust aftertreatment device (16) and the second exhaust gas supply line (34) is arranged downstream of the second exhaust aftertreatment device (18).The exhaust system (10) according to claim 14, further comprising: a diagnostic device (30) configured to detect a malfunction in exhaust gas aftertreatment by means of the first and second exhaust gas aftertreatment device (16, 18) based on a signal from the exhaust gas sensor (46) and preferably to output a warning in the event of detection of the malfunction.

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