Mixing device for mixing a liquid injection injected into the exhaust gases of an internal combustion engine with the exhaust gases

Abstract

In a mixing device for mixing an injection into exhaust gas of an internal combustion engine, a mixing chamber formed in a mixing chamber structure assembly has a first mixing chamber sub-region defined by an upstream mixing chamber structure assembly wall and a downstream mixing chamber structure assembly wall and a second mixing chamber sub-region defined by the upstream mixing chamber structure assembly wall and the downstream mixing chamber structure assembly wall. An injection output unit is provided for outputting injection into a mixing chamber boundary region. At least one first inlet is provided in the upstream mixing chamber structure assembly wall and at least one first outlet is provided in the downstream mixing chamber structure assembly wall in a configuration with the first mixing chamber sub-region. At least one second inlet is provided in the upstream mixing chamber structure assembly wall and at least one second outlet is provided in the downstream mixing chamber structure assembly wall in a configuration with the second mixing chamber sub-region. The at least one first inlet and the at least one first outlet are arranged offset from each other in a first or / and second direction.

Description

Technical Field

[0001] This invention relates to a mixing apparatus for mixing a liquid injector injected into the exhaust gas of an internal combustion engine with the exhaust gas. Background Technology

[0002] To reduce harmful substances in exhaust gases from internal combustion engines, it is known to inject an injector into the exhaust gases flowing through the exhaust system. This injector can be, for example, urea / water solution, which is used in a downstream SCR catalyst to reduce nitrogen oxides in the exhaust gases. In another design type, fuel, i.e., diesel, can be injected into the exhaust gases to generate heat of reaction through a catalytic reaction on a downstream catalyst, which is then used to heat the catalyst or, for example, a downstream particulate filter.

[0003] The problem with injecting such a propellant, such as urea / water solution or diesel fuel, is that such propellants are often mixtures of components with different boiling points. For example, the liquid component contained in diesel fuel has a boiling point in the range of, for example, 180°C to, for example, 430°C. This means that such a propellant may contain a component with a boiling point that can be above the exhaust gas temperature emitted by an internal combustion engine, and this component, when injected into the exhaust gas, may be converted into a gaseous state much less readily than a liquid composition with a lower boiling point.

[0004] Another problem when injectable reagents are injected into the exhaust gases from an internal combustion engine can be insufficient or uneven mixing of the reagents with the exhaust gases. Such uneven mixing can result in the reagents, which are injected into the exhaust gases as liquids, not being converted into a gaseous state and therefore not being effectively used for subsequent catalytic or oxidation reactions. Summary of the Invention

[0005] The object of the present invention is to provide a mixing device for mixing a liquid reactant injected into the exhaust gas of an internal combustion engine with the exhaust gas, thereby achieving effective conversion of the reactant to a gaseous state and uniform mixing of the exhaust gas and the reactant.

[0006] According to the present invention, this objective is achieved by a mixing device for mixing a liquid injector injected into the exhaust gas of an internal combustion engine with the exhaust gas, comprising:

[0007] - An exhaust gas guiding assembly extending along the longitudinal axis through which exhaust gas can flow in the main exhaust gas flow direction, wherein an exhaust gas flow rate is formed in the exhaust gas guiding assembly through which exhaust gas can flow substantially in the main exhaust gas flow direction.

[0008] - A mixing chamber structural assembly, including an upstream mixing chamber structural assembly wall defining an upstream mixing chamber in the exhaust gas flow direction and a downstream mixing chamber structural assembly wall defining a downstream mixing chamber in the exhaust gas flow direction.

[0009] - Injection dispensing unit, used to dispense liquid injection solution into the mixing chamber substantially along the injection dispensing line in the main injection dispensing direction.

[0010] In the mixing device constructed according to the present invention, the mixing chamber has a first mixing chamber sub-region defined by an upstream mixing chamber structural component wall and a downstream mixing chamber structural component wall, and a second mixing chamber region defined by the upstream mixing chamber structural component wall and the downstream mixing chamber structural component wall. The first and second mixing chamber regions are positioned side-by-side, substantially transverse to the main exhaust gas flow direction, along a first direction and open to each other in the mixing chamber boundary region. The mixing chamber boundary region extends elongatedly along a second direction substantially orthogonal to the first direction and substantially transverse to the main exhaust gas flow direction. An injection dispensing unit is configured to dispense an injection into the mixing chamber boundary region. The first mixing chamber region is configured with at least one first inlet in the upstream mixing chamber structure component wall and at least one first outlet in the downstream mixing chamber structure component wall. The second mixing chamber region is configured with at least one second inlet in the upstream mixing chamber structure component wall and at least one second outlet in the downstream mixing chamber structure component wall. In the first mixing chamber region, at least one first inlet and at least one first outlet are staggered from each other along a first direction and / or along a second direction. In the second mixing chamber region, at least one second inlet and at least one second outlet are staggered from each other along the first direction and / or along the second direction.

[0011] The mixing chamber is divided into two interconnected sub-regions, with the injectable solution fed by the injection output unit. This process distributes the injected solution across the two sub-regions or volume regions of the entire mixing chamber. In each sub-region, vortices are generated, specifically through corresponding inlets and outlets positioned relative to each other. These vortices, on the one hand, ensure effective mixing of the injectable solution with the portion of the exhaust gas flowing through the respective mixing chamber region, and on the other hand, maintain a relatively long contact duration between the injectable solution in the injected exhaust gas and the surfaces of the distinct mixing chamber regions defined by the walls of the mixing chamber structural components. This results in more time available for components of the liquid injectable solution that transition to a gaseous state, for example, based on a higher boiling point, a lower or slower transition, to a gaseous state through thermal absorption. Simultaneously, the vortices generated in the mixing chamber regions ensure that localized accumulation of the liquid injectable solution does not occur under gravity, thereby preventing, for example, injectable solution deposition on the walls of the mixing chamber structural components.

[0012] Effective vortices can be generated in the mixing chamber region by the fact that the first and second directions are substantially orthogonal to the main exhaust gas flow direction and / or the longitudinal axis, and / or the main injection output direction is substantially orthogonal to the main exhaust gas flow direction and / or the longitudinal axis and / or substantially corresponds to the second direction.

[0013] In order to ensure that the injected agent is substantially uniformly distributed on the two mixing chamber regions, the mixing chamber boundary regions can be configured such that they are substantially formed by mixing chamber boundary openings, wherein the mixing chamber boundary openings are substantially located in an opening plane that is opened by the main flow direction of the exhaust gas and the second direction and is orthogonal to the first direction.

[0014] The injection outlet line can be located substantially in the open plane and / or substantially orthogonal to the main flow direction of the exhaust gas.

[0015] To avoid flow short-circuiting that affects eddy generation in the mixing cavity region, it is proposed that at least one first inlet and at least one first outlet do not substantially overlap along the second direction, or / and at least one second inlet and at least one second outlet do not substantially overlap along the second direction.

[0016] Furthermore, it can be configured such that at least one first inlet and at least one first outlet do not overlap at least partially along the first direction, or / and at least one second inlet and at least one second outlet do not overlap at least partially along the first direction.

[0017] In order to ensure uniform mixing of exhaust gas and injectable agent in the two mixing chamber regions, at least one first inlet and at least one second inlet may be arranged substantially mirror-symmetrically with respect to the opening plane, or / and at least one first outlet and at least one second outlet may be arranged substantially mirror-symmetrically with respect to the opening plane.

[0018] If at least one first inlet and at least one second inlet have an inlet spacing from the opening plane, and at least one first outlet and at least one second outlet have an outlet spacing from the opening plane that is different from the inlet spacing, then the generation of vortices in the two mixing chamber regions is further supported.

[0019] To achieve a defined flow guide that supports effective mixing of exhaust gas and injectable agent along the wall of the mixing chamber structure assembly, the following can also be configured:

[0020] - The upstream mixing cavity structural component wall arches upstream along its longitudinal axis in the wall region defining the first mixing cavity sub-region in the upstream direction, and in the wall region defining the second mixing cavity region in the upstream direction, and in the second sub-region surrounding the second mixing cavity region, arches upstream along its longitudinal axis, or / and

[0021] -The downstream mixing chamber structure component wall arches downstream in the longitudinal direction of the first sub-region surrounding the first mixing chamber region in the wall region defining the first mixing chamber region in the downstream direction, and arches downstream in the longitudinal direction of the second sub-region surrounding the second mixing chamber region in the wall region defining the second mixing chamber region in the downstream direction.

[0022] For example, the design scheme could be as follows:

[0023] - The upstream and downstream walls of the mixing cavity structure components arch in their respective defining first mixing cavity sub-regions such that the first mixing cavity sub-region has a substantially circular, preferably circular, elliptical, or oval cross-sectional profile about the longitudinal axis of the first sub-region, and / or

[0024] - The upstream and downstream walls of the mixing cavity structure components arch in their respective wall regions defining the second mixing cavity sub-regions such that the second mixing cavity sub-regions have a substantially circular, preferably circular, elliptical, or oval cross-sectional profile about the longitudinal axis of the second sub-region.

[0025] In order to provide the largest possible volume for each of the two mixing cavity regions, it is proposed that: the first mixing cavity region is substantially cylindrical about the longitudinal axis of the first sub-region and the second mixing cavity region is substantially cylindrical about the longitudinal axis of the second sub-region, or / and the longitudinal axes of the first and second sub-regions are substantially parallel to each other.

[0026] To obtain a design scheme that effectively avoids the formation of sediments, it is proposed that: the first mixing chamber region is preferably formed in a conical radial extension along the longitudinal axis of the first sub-region, and the second mixing chamber region is preferably formed in a conical radial extension along the longitudinal axis of the second sub-region, or / and the longitudinal axes of the first and second sub-regions are set at an angle to each other.

[0027] Specifically, it can be configured such that at least one first inlet is located in the region of the smaller radius of the first mixing chamber region and at least one first outlet is located in the region of the larger radius of the first mixing chamber region, or / and at least one second inlet is located in the region of the smaller radius of the second mixing chamber region and at least one second outlet is located in the region of the larger radius of the second mixing chamber region.

[0028] The extended structure of the mixing chamber region can be so effectively integrated into the cross-section of the exhaust gas guiding assembly in a compact form, such that the longitudinal axes of the first and second sub-regions are angled relative to each other, such that the interval between the longitudinal axes of the first and second sub-regions in the smaller radius region of the first and second mixing chamber regions is smaller than the interval between the longitudinal axes of the first and second sub-regions in the larger radius region of the first and second mixing chamber regions.

[0029] The longitudinal axes of the first and second sub-regions can be set substantially mirror-symmetrically with respect to the opening plane, regardless of whether they extend parallel or at an angle to each other. Furthermore, the longitudinal axes of the first and second sub-regions can be configured to lie in an axial plane substantially orthogonal to the opening plane.

[0030] In order to ensure uniform mixing of exhaust gas and injectable agent in the two mixing chamber regions, the first mixing chamber region and the second mixing chamber region can be configured to be substantially mirror-symmetrical about the opening plane.

[0031] Furthermore, this can support the generation of helically wound vortices guided along the inner side of the wall of the hybrid cavity structure component, i.e.:

[0032] - At least one guide extending locally about the longitudinal axis of the first sub-region is provided on the inner side of the wall region defining the first mixing chamber sub-region in the upstream direction of the upstream mixing chamber structural component wall, and / or...

[0033] - At least one guide extending locally about the longitudinal axis of the second sub-region is provided on the inner side of the wall region defining the second mixing chamber sub-region in the upstream direction of the upstream mixing chamber structural component wall, and / or...

[0034] - At least one flow guide extending locally about the longitudinal axis of the first sub-region is provided on the inner side of the wall region defining the first mixing chamber sub-region in the downstream direction of the mixing chamber structural component wall, and / or...

[0035] - At least one guide extending locally around the longitudinal axis of the second sub-region is provided on the inner side of the wall region defining the second mixing chamber sub-region in the downstream direction of the mixing chamber structure component wall.

[0036] This allows for the targeted introduction of exhaust gas flowing onto the mixing chamber structure assembly into two mixing chamber regions, namely:

[0037] - A guide member is provided on the wall region defining the first mixing chamber sub-region in the upstream direction of the wall of the upstream mixing chamber structural assembly, extending inward toward the exhaust gas guiding assembly and defining at least one first inlet, and / or...

[0038] - A guide member is provided on the wall region of the upstream mixing chamber structure assembly wall that defines the second mixing chamber sub-region in the upstream direction, extending in the direction toward the inside of the exhaust gas guiding assembly and defining at least one second inlet.

[0039] The present invention also relates to an internal combustion engine exhaust system, comprising at least one exhaust gas treatment device and a mixing device configured according to the present invention upstream of the at least one exhaust gas treatment device. Attached Figure Description

[0040] The invention is described in detail below with reference to the accompanying drawings. In the drawings:

[0041] Figure 1 A schematic diagram of an exhaust system for an internal combustion engine;

[0042] Figure 2 Shown in Figure 1 A longitudinal section view of the exhaust equipment in the region of the mixing chamber structural component of the exhaust equipment;

[0043] Figure 3 Show Figure 2 The mixing chamber structure assembly along Figure 2 View of direction III;

[0044] Figure 4 An exploded perspective view of the mixing device is shown;

[0045] Figure 5 Shown in perspective Figure 4 The mixing device includes two mixing chamber structural components and a mixing chamber structural component wall;

[0046] Figure 6 Shown in Figure 5 The hybrid cavity structure assembly shown in the figure is along Figure 5 The view of the VI;

[0047] Figure 7 The basis for illustrating alternative design types of hybrid cavity structure components. Figure 5 The view;

[0048] Figure 8 Show Figure 7 The mixing chamber structure assembly along Figure 7 The view directed towards VIII;

[0049] Figure 9 An exploded perspective view showing alternative design options for the mixing device;

[0050] Figure 10 Show Figure 9 A perspective view of the mixing device, including the walls of two mixing chamber structural components;

[0051] Figure 11 Show Figure 10 The mixing chamber structure assembly along Figure 10 The view of direction XI in the middle;

[0052] Figure 12 Show Figure 10 The mixing chamber structure assembly along Figure 11 The view of XII in the direction of the view;

[0053] Figure 13 An exploded perspective view showing another alternative design type of the mixing device;

[0054] Figure 14 Show Figure 13 A perspective view of the mixing device, including the walls of two mixing chamber structural components;

[0055] Figure 15 Show Figure 14 The mixing chamber structure assembly along Figure 14 The view in the XV direction;

[0056] Figure 16 Show Figure 14 The mixing chamber structure assembly along Figure 15 The view in the XVI direction. Detailed Implementation

[0057] exist Figure 1 The diagram shows a portion of an exhaust system, generally indicated by 10, of an internal combustion engine, such as in a vehicle. The exhaust system 10 includes, for example, a catalyst device, such as an SCR catalyst, and includes an exhaust gas treatment device 12, which is supplied with exhaust gases emitted from the internal combustion engine. Upstream of the exhaust gas treatment device 12 is a mixing device, generally indicated by 14, which includes, for example, a tubular exhaust gas guide assembly 16. The exhaust gas A emitted from the internal combustion engine flows along the main exhaust gas flow direction H. A The exhaust gas flow 18 formed in the exhaust gas guiding assembly 16 flows to the mixing device 14 or the mixing chamber structure assembly 20 of the mixing device.

[0058] Hybrid cavity structure assembly 20 includes—as particularly Figure 2 As can be seen in the image—the upstream mixing chamber structure component wall 22 and the direction along the longitudinal axis L of the exhaust gas guiding component 16 or along the main exhaust gas flow direction H. A Immediately following the upstream mixing chamber structural component wall 22 is the downstream mixing chamber structural component wall 24. The two mixing chamber structural component walls 22 and 24 define the mixing chamber 26 of the mixing chamber structural component 20 substantially in the upstream and downstream directions, respectively. The outer peripheral contours of the mixing chamber structural component 20 or the mixing chamber structural component walls 22 and 24 are along the main exhaust gas flow direction H. AUnder observation, the inner circumferential contour of the exhaust gas guiding assembly 16 is matched. If the exhaust gas guiding assembly has a substantially circular inner circumferential contour, then the walls 22 and 24 of the two mixing chamber structure components have corresponding substantially circular outer circumferential contours, so that the mixing chamber structure component 20 can be inserted substantially precisely into the exhaust gas guiding assembly 16 without substantially obstructing the main exhaust gas flow direction H. A The exhaust gas A flowing to the mixing chamber structure assembly 20 can flow in the direction of the exhaust gas treatment device 12 next to the mixing chamber structure assembly 20 without flowing through the mixing chamber 26.

[0059] The two mixing chamber structural component walls 22 and 24 are formed such that the two mixing chamber sub-regions 28 and 30 forming the mixing chamber 26 are open to each other in the mixing chamber boundary region 27. Corresponding to the first mixing chamber sub-region 28, the upstream mixing chamber structural component wall 22 has a wall region 32 that is, for example, circularly arched in an upstream direction. The wall region 32 arches around the longitudinal axis T1 of a first sub-region of the first mixing chamber sub-region 28. Correspondingly, corresponding to the second mixing chamber region 30, the upstream mixing chamber structural component wall 22 has a wall region 34 that, for example, circularly arches around the longitudinal axis T2 of a second sub-region of the second mixing chamber region 30 in an upstream direction.

[0060] The downstream mixing chamber structure component wall 24 is configured with the first mixing chamber sub-region 28 and has, for example, a wall region 36 that circularly surrounds the longitudinal axis T1 of the first sub-region, and is configured with the second mixing chamber region 28 and has, for example, a wall region 38 that circularly surrounds the longitudinal axis T2 of the second sub-region and arches in the downstream direction.

[0061] Wall regions 32 and 36 define a generally cylindrical structure of the first mixing chamber region 28 extending along the longitudinal axis T1 of the first sub-region. Similarly, wall regions 34 and 38 define a generally cylindrical structure of the second mixing chamber region 30 extending along the longitudinal axis T2 of the second sub-region.

[0062] A mixing chamber boundary opening 40 is formed between the boundary regions between wall regions 32 and 34 and the boundary regions between wall regions 36 and 38, forming a mixing chamber boundary region 27. The mixing chamber boundary opening 40 extends along the main exhaust gas flow direction H. A The longitudinal axis L of the exhaust gas guiding assembly 16 extends in the direction of the second direction R2, which is orthogonal to it. The longitudinal axes T1 and T2 of the two sub-regions also extend substantially parallel to each other along the second direction R2 and are therefore located in an axial plane E2 that is substantially orthogonal to the longitudinal axis L. The axial plane E2 is also perpendicular to the spatial position of the mixing chamber boundary opening 40, or the opening plane E1 that defines the mixing chamber boundary opening. The spatial position of plane E1 is substantially determined, on the one hand, by the main exhaust gas flow direction H. AOr, the longitudinal axis L is defined by the second direction R2. The longitudinal axes T1 and T2 of the two sub-regions are spaced apart from the opening plane E1 along the first direction R1. The first direction R1 is parallel to the second direction R2, and also to the longitudinal axis L or the main exhaust gas flow direction H. A And thus it is also orthogonal to the opening plane E1.

[0063] In the region of mixing chamber 26, the reactant R, which is to be fully mixed with the exhaust gas A, is delivered by an injection output unit 42, which is carried on the exhaust gas guiding assembly 16 and is generally referred to as a syringe, in the main injection output direction H. R The injection is injected into the mixing chamber 26 along the injection output line B in the region of the mixing chamber boundary opening 40. Here, the injection output line B of the injection R, injected essentially in the form of a jet cone, lies in the opening plane E1 and is substantially perpendicular to the longitudinal axis L and the first direction R1. Therefore, the main output direction H of the injection is... R The injection output line B is substantially parallel to the second direction R2 and also to the longitudinal axes T1 and T2 of the sub-regions, and the injection output line B—which substantially defines the central longitudinal axis of the injection cone of R—lies in the axial plane E2 along with the longitudinal axes T1 and T2 of the two sub-regions. Generally, the injection output line B thus defines the longitudinal centerline that substantially defines the shape of the output injection R, i.e., the geometry of the injection cone, for example.

[0064] By injecting the injectable agent R into the mixing chamber 26 in the region of the mixing chamber boundary opening 40, the injectable agent R reaches the first mixing chamber sub-region 28 and the second mixing chamber region 30 in substantially equal amounts. To ensure adequate mixing of these amounts of injectable agent R with the exhaust gas A, the upstream mixing chamber structural assembly wall 22, configured in wall region 32 with respect to the first mixing chamber region 28, has a first inlet 44. Similarly, the upstream mixing chamber structural assembly wall 22, configured in wall region 34 with respect to the second mixing chamber region 30, has a second inlet 46. The inlets 44 and 46 are located on the upstream mixing chamber structural assembly wall 22 in a peripheral region away from or diametrically opposed to the location of the injectable agent output unit 42, and are substantially mirror-symmetrical about the opening plane E.

[0065] The two inlets 44 and 46 are positioned with a relatively small inlet spacing from the opening plane E1, thus essentially along the main exhaust gas flow direction H. A The exhaust gas A flowing to the mixing chamber structure assembly 20 enters the mixing chamber sub-regions 28 and 30 in the region relatively close to the opening plane E1, at the end region axially spaced from the injection outlet unit 42 along the longitudinal axes T1 and T2 of the sub-region. Because the injection R is also injected into this central region of the mixing chamber 26, the exhaust gas A, having already flowed into the mixing chamber regions 28 and 30, comes into contact with and begins to mix with the injection R.

[0066] In the downstream mixing chamber structure assembly wall 24, a first outlet 48 is formed in wall region 36, configured with respect to the first mixing chamber sub-region 28. Similarly, a second outlet 50 is formed in wall region 38 of the downstream mixing chamber structure assembly wall 24, configured with respect to the second mixing chamber region 30. For example... Figure 3 As indicated, the first outlet 48 and the second outlet 50 are located in the downstream mixing chamber structure assembly wall 24, which is situated in the peripheral region near the injection dispensing unit 42 and has an outlet spacing from the opening plane E1 that is greater than the inlet spacing. It should be noted that the inlet spacing and outlet spacing can be defined, for example, by the minimum spacing between the inlets 44, 46 or outlets 48, 50 and the opening plane E1. If multiple first or second inlets 44, 46 or outlets 48, 50 are respectively provided in relation to the first mixing chamber region 28 or the second mixing chamber region 30, then the minimum spacing between the inlet or outlet located closest to the opening plane E1 can be considered as the inlet spacing or outlet spacing.

[0067] Because the exhaust gas A flowing into the two mixing chamber sub-regions 28 and 30 through inlets 44 and 46 can each exit the mixing chamber sub-regions 28 and 30 only through their outlets 48 and 50, the exhaust gas A flowing through the mixing chamber sub-regions 28 and 30 is forced to form a spiral vortex surrounding the longitudinal axis T1 or T2 of the respective sub-region. In this vortex, the exhaust gas A carries the injectable agent R injected in the region of the mixing chamber boundary opening 40 so that it flows in the circumferential direction around the longitudinal axis T1 and T2 of the configured sub-region, and thus, due to the centrifugal force, the injectable agent R injected in the form of droplets is squeezed radially outward with respect to the longitudinal axis T1 and T2 of the respective sub-region. This supports the injectable agent R to contact the inner surface of the walls 22 and 24 of the mixing chamber structural components and thereby absorb heat from them.

[0068] Because the exhaust gas A and the injected agent R flow through the mixing chamber regions 28 and 30 in a spiral-wound vortex rather than linearly, a relatively long residence time of the mixture G formed by the exhaust gas A and the injected agent R is ensured, wherein heat is enhancedly transferred to the injected agent R through contact with the inner surfaces of the walls 22 and 24 of the mixing chamber structure components formed or appearing during this flow, and thus also facilitates its evaporation or transformation into a gaseous state.

[0069] A substantially homogeneous mixture G, consisting of waste gas A and gaseous injectable agent R, exits the mixing chamber 26 or mixing chamber structure assembly 20 through two outlets 48 and 50 and can then flow toward the waste gas treatment device 12, for example, to carry out a catalytic or oxidation reaction.

[0070] Because the two mixing chamber regions 28 and 30 are substantially mirror-symmetrical about the opening plane E1, their substantially cylindrical cross-sectional geometry, which extends slenderly along the longitudinal axes T1 and T2 of the respective sub-regions, also supports the uniform and efficient mixing of the injector R with the exhaust gas A through the uniform distribution of the injector R injected in the region of the mixing chamber boundary opening 40, and the corresponding uniform and substantially complete transformation of the injector injected in liquid or droplet form into a gaseous state in each mixing chamber region 28 and 30.

[0071] The generation of two mutually opposing flow vortices in the two mixing chamber sub-regions 28 and 30 is supported, on the one hand, by the offset positioning of the corresponding inlets 44 and 46 and outlets 48 and 50 along a first direction R1, and by the offset positioning of the inlets 44 and 46 with respect to the configured outlets 48 and 50 along a second direction R2. Because a relatively large interval exists, particularly between the mutually configured inlets 44 and 46 and outlets 48 and 50, along the longitudinal axis T1 or T2 of the corresponding sub-region, direct flow short-circuiting through the mutually configured openings is impossible. At the same time, the helical flow of exhaust gas guided through the mixing chamber regions 28 and 30 is blocked: when the inlets 44 and 46 are positioned in the lower region along the vertical direction, the liquid injection agent R accumulated on the inner side of the mixing chamber structural component walls 22 and 24 flows downward and accumulates in the lower region at a position adjacent to the inner surface of the mixing chamber structural component walls 22 and 24 of the exhaust gas guiding component 16, forming deposits. The gravity-induced extension of the residence time of the injectable R in the mixing chamber 26, guided by the helical flow along the longitudinal axes T1 and T2 of the corresponding sub-regions, is curbed, thus allowing more time for its transformation into a gaseous state. Therefore, it also minimizes the possibility of unevaporated or vaporized injectable R, existing as water droplets, being discharged from the mixing chamber 26 along with waste gas A.

[0072] Before describing in detail the different structural designs of such a mixing device 14, it should be noted that designs different from this, for example, are also possible. Figure 2 The diagram illustrates the selection of the cross-sectional geometry of the hybrid cavity regions. For example, by shaping the wall regions 32, 34, 36, and 38 with a less pronounced arch, the hybrid cavity regions 28 and 30, which are in principle configured to have a substantially cylindrical shape, can have a substantially elliptical or, if possible, oval cross-sectional geometry about the longitudinal axis T1 or T2 of the sub-region.

[0073] Figures 4 to 6 The first structural design of the mixing device 14 is shown, which is substantially the same as the one previously described. Figures 1 to 3The design scheme described herein includes two mixing chamber structural component walls 22, 24, each having an arched wall region 32, 34 or 36, 38 facing upstream or downstream. In this design example, the two inlets 44, 46 can be moved inward to the opening plane E1 or the mixing chamber boundary opening 40 such that the inlets 44, 46 transition directly to each other and therefore their distance from the opening plane E1 is zero.

[0074] The two mixing chamber structural component walls 22, 24 are configured as sheet metal parts and can be connected to the inner surface of the multi-piece exhaust gas guiding component 16 in the illustrated design example by material locking, such as brazing or welding, thereby ensuring that the mixing chamber structural component walls 22, 24 are sealed to the inner surface of the exhaust gas guiding component 16, in particular, to prevent leakage.

[0075] This type of design scheme is modified in Figure 7 and 8 As shown in the diagram. In this modification, the two inlets 44, 46 are further moved outward, i.e., away from the opening plane E1 or the mixing chamber boundary opening 40 along the first direction R1. The outlets 48, 50 may also have... Figures 4 to 6 The visible positioning, or can be further inward, that is, moved to the opening plane E1 or the boundary opening 40 of the mixing cavity, so that on the one hand, the inlets 44, 46 and on the other hand, their respective configured outlets 48, 50 not only do not overlap along the direction of the longitudinal axis T1 or T2 of the corresponding sub-region and have an axial gap, but also have a stronger offset between them along the first direction R1, so as to support the generation of vortices.

[0076] To further support eddies, such as Figure 7 As can be seen, for example, plate-shaped flow guides 52 and 54 are provided on the inner surface of the downstream mixing chamber structure component wall 24, which locally surround the longitudinal axis of their respective sub-regions, extending substantially along the flow direction of the vortex. This effectively prevents direct flow short-circuiting from the inlets 44 and 46 to the outlets 48 and 50. It should be emphasized that, alternatively or additionally, such flow guides may also be provided on the upstream mixing chamber structure component wall 22.

[0077] Figures 9 to 12 The alternative design types of the mixing device 14 are shown, among which, particularly in Figure 10 and 12 As can be seen, the arched wall regions 32 and 34 of the upstream mixing cavity structure component wall 22 are more curved in the upstream direction, and in the case of a circular arch, they have a smaller radius of curvature. As a result, offsets are generated between wall regions 32 and 36 or between wall regions 34 and 38 in the region that are spaced apart from the opening plane E1 or the mixing cavity boundary opening 40.

[0078] In the case of each wall region 32, 34, a guide member 56, 58 extending outward from the wall region in a direction away from the opening plane E1 is provided on the upstream mixing chamber structure component wall 22, and an inlet 44, 46 is formed thereunder. To improve stability, guide sections 60, 62 extending inward, i.e., toward the opening plane E1 or the mixing chamber boundary opening 40, may also be formed on the corresponding wall regions 36, 38 of the downstream mixing chamber structure component wall 24, together with the guide members formed on the upstream mixing chamber structure component wall 22, defining the corresponding inlets 44, 46.

[0079] like Figure 10 As clearly seen, in this design type, the mixing chamber boundary opening 40 in the mixing chamber boundary region 27 is constrained along the second direction R2, thereby separating the two mixing chamber sub-regions 28, 30 from each other in the region of the mixing chamber 26 away from the injection output unit 42. For this purpose, a wall member can be applied, for example, between the two mixing chamber regions 28, 30. Alternatively, in this design, two members separated in the opening plane E1 can be provided, one member providing wall regions 32 and 36 and the other member providing wall regions 34 and 38. The upstream mixing chamber structural assembly wall 22, including wall regions 32, 34, is therefore composed of two parts, as is the downstream mixing chamber structural assembly wall 24, including wall regions 36, 38.

[0080] Another alternative design for the mixing device 14 is... Figures 13 to 16 As shown in the diagram. In this design, the downstream mixing chamber structure component wall 24 can, for example, be configured as previously described. Figures 4 to 12 That is, the wall regions 36 and 38 arch with a cylindrical geometry about their respective configured sub-region longitudinal axes T1 and T2. The upstream mixing chamber structure component wall 22 arches upstream in its wall regions 32 and 34 such that a tapered cross-sectional geometry is formed along the direction of the respective configured sub-region longitudinal axes T1 and T2 defined by the molding of the upstream mixing chamber structure component wall 22. The sub-region longitudinal axes T1 and T2 thus defined are then angled to each other and, for example, in the axial plane E2, wherein, in the lower region, that is, in the region near the inlets 44 and 46, the sub-region longitudinal axes T1 and T2 have a smaller interval and are dispersed from each other toward the outlets 48 and 50.

[0081] On the upstream mixing chamber structure component wall 22, in the case of each wall region 32, 34, at the end region away from the opening plane E1, there are guides 64, 66 extending outward or downstream of the mixing chamber structure component wall 24, and corresponding inlets 44 or 46 are formed thereunder.

[0082] The conical arches of the wall regions 32 and 34, which have cross-sectional geometries that extend radially along the longitudinal axes T1 and T2 of their respective sub-regions, result in higher flow velocities in the regions near the inlets 44 and 46, based on the smaller cross-sectional geometries of the mixing chamber sub-regions 28 and 30. This, in turn, contributes to higher centrifugal forces due to eddies and thus facilitates the effective carrying of the injectable into the mixing chamber regions 28 and 30 near the inlets 44 and 46. This effectively prevents the accumulation of liquid injectable in the lower or near-inlet regions 28 and 30 of the mixing chamber regions 28 and 30 along the vertical direction.

[0083] In this modified design, the downstream hybrid cavity structure component wall 24 can also arch in its wall regions 36 and 38 with a tapered geometry about the longitudinal axes T1 and T2 of their respective sub-regions, thereby making the increased cross-sectional size along the axial direction of the longitudinal axes T1 and T2 of the sub-regions more obvious.

[0084] In principle, in the mixing device constructed according to the present invention, the two mixing chamber regions 28 and 30 can also be configured such that, with respect to the longitudinal axis L or the main flow direction of the exhaust gas H, they are positioned such that... A Positioning such that the longitudinal axes T1, T2 of its subregions are angled about the axial plane E2 and, for example, inclined downstream or upstream in the direction from inlets 44, 46 to outlets 48, 50.

Claims

1. A mixing apparatus for mixing an injectable agent (R) injected into exhaust gas (A) of an internal combustion engine with said exhaust gas (A), said mixing apparatus comprising: - Extending along the longitudinal axis (L), from the exhaust gas (A) along the main exhaust gas flow direction (H) A The exhaust gas can flow through the exhaust gas guiding assembly (16), wherein the exhaust gas is formed in the exhaust gas guiding assembly (16) substantially along the main exhaust gas flow direction (H). A ) The flow rate of exhaust gas that can pass through (18). - A mixing chamber structure assembly (20) comprising an upstream mixing chamber structure assembly wall (22) defining a mixing chamber (26) in the upstream direction of the exhaust gas flow (18) and a downstream mixing chamber structure assembly wall (24) defining a mixing chamber (26) in the downstream direction of the exhaust gas flow (18). - Injection output unit (42), the injection output unit is used substantially in the main injection output direction (H R Liquid injection solution (R) is output along the injection output line (B) into the mixing chamber (26). The mixing chamber (26) has a first mixing chamber sub-region (28) defined by an upstream mixing chamber structural component wall (22) and a downstream mixing chamber structural component wall (24), and a second mixing chamber region (30) defined by the upstream mixing chamber structural component wall (22) and the downstream mixing chamber structural component wall (24). The first mixing chamber region (28) and the second mixing chamber region (30) are substantially transverse to the main exhaust gas flow direction (H) along a first direction (R1). A The components are positioned side by side and open to each other in the boundary region (27) of the mixing chamber, which is substantially transverse to the main flow direction of the exhaust gas along a second direction (R2) that is substantially orthogonal to the first direction (R1). A The injection output unit (42) is elongated and configured to output injection (R) into the mixing chamber boundary region (27). It is configured with at least one first inlet (44) in the upstream mixing chamber structure component wall (22) and at least one first outlet (48) in the downstream mixing chamber structure component wall (24) in relation to the first mixing chamber sub-region (28). It is configured with at least one second inlet (46) in the upstream mixing chamber structure component wall (22) and at least one second outlet (50) in the downstream mixing chamber structure component wall (24) in relation to the second mixing chamber sub-region (30). The at least one first inlet (44) and at least one first outlet (48) in the first mixing chamber sub-region (28) are staggered from each other along a first direction (R1) and / or along a second direction (R2). The at least one second inlet (46) and at least one second outlet (50) in the second mixing chamber region (30) are staggered from each other along a first direction (R1) and / or along a second direction (R2).

2. The mixing device according to claim 1, characterized in that, The first direction (R1) and the second direction (R2) are different from the main flow direction of the exhaust gas (H). A ) or / and substantially orthogonal to the longitudinal axis (L), or / and the main output direction of the injection (H) R ) and the main flow direction of exhaust gas (H) A ) or / and substantially orthogonal to the longitudinal axis (L) or / and substantially corresponding to the second direction (R2).

3. The mixing apparatus according to claim 1 or 2, characterized in that, The mixing chamber boundary region (27) is essentially formed by the mixing chamber boundary opening (40), wherein the mixing chamber boundary opening (40) is essentially located in an opening plane (E1) that is opened by the main flow direction (H) and the second direction (R2) and is orthogonal to the first direction (R1).

4. The mixing apparatus according to claim 3, characterized in that, The injection outlet line (B) is substantially located in the opening plane (E1) and / or in the direction of the main exhaust gas flow (H). A They are basically orthogonal.

5. The mixing apparatus according to any one of claims 1 to 4, characterized in that, The at least one first inlet (44) and at least one first outlet (48) are substantially non-overlapping along the second direction (R2), or / and the at least one second inlet (46) and at least one second outlet (50) are substantially non-overlapping along the second direction (R2).

6. The mixing apparatus according to any one of claims 1 to 5, characterized in that, The at least one first inlet (44) and at least one first outlet (48) are at least partially non-overlapping along the first direction (R1), or / and the at least one second inlet (46) and at least one second outlet (50) are at least partially non-overlapping along the first direction (R1).

7. The mixing apparatus according to any one of claims 1 to 6, with reference to claim 3, characterized in that, The at least one first inlet (44) and the at least one second inlet (46) are arranged substantially mirror-symmetrically with respect to the opening plane (E1), and / or the at least one first outlet (48) and the at least one second outlet (50) are arranged substantially mirror-symmetrically with respect to the opening plane (E1).

8. The mixing apparatus according to any one of claims 1 to 7, with reference to claim 3, characterized in that, The at least one first inlet (44) and at least one second inlet (46) have an inlet interval with the opening plane (E1), and the at least one first outlet (48) and at least one second outlet (50) have an outlet interval with the opening plane (E1) that is different from the inlet interval.

9. The mixing apparatus according to any one of claims 1 to 8, characterized in that, -The upstream mixing cavity structure component wall (22) arches upstream in the wall region (32) defining the first mixing cavity sub-region (28) along the longitudinal axis (T1) of the first sub-region surrounding the first mixing cavity region (28) and arches upstream in the wall region (34) defining the second mixing cavity region (30) along the longitudinal axis (T2) of the second sub-region surrounding the second mixing cavity region (30), or / and -The downstream mixing cavity structure component wall (24) arches downstream in the wall region (36) that defines the first mixing cavity sub-region (28) in the downstream direction, along the longitudinal axis (T1) of the first sub-region surrounding the first mixing cavity region (28), and arches downstream in the wall region (38) that defines the second mixing cavity region (30) in the downstream direction, along the longitudinal axis (T2) of the second sub-region surrounding the second mixing cavity region (30).

10. The mixing apparatus according to claim 9, characterized in that, - The upstream and downstream mixing cavity structure component walls (22 and 24) arch in their respective wall regions (32, 36) defining the first mixing cavity sub-region (28), such that the first mixing cavity sub-region (28) has a substantially circular, preferably circular, elliptical, or oval cross-sectional profile about the longitudinal axis (T1) of the first sub-region, and / or - The upstream and downstream hybrid cavity structure component walls (22 and 24) arch in their respective wall regions (34, 38) defining the second hybrid cavity sub-region (30), such that the second hybrid cavity sub-region (30) has a substantially circular, preferably circular, elliptical, or oval cross-sectional profile about the longitudinal axis (T2) of the second sub-region.

11. The mixing apparatus according to claim 9 or 10, characterized in that, The first mixing cavity region (28) is substantially cylindrical about the longitudinal axis (T1) of the first sub-region, and the second mixing cavity region (30) is substantially cylindrical about the longitudinal axis (T1) of the second sub-region, or / and the longitudinal axis (T1) of the first sub-region and the longitudinal axis (T2) of the second sub-region are substantially parallel to each other.

12. The mixing apparatus according to claim 9 or 10, characterized in that, The first mixing cavity region (28) is radially extended along the longitudinal axis (T1) of the first sub-region, preferably radially extended in a conical shape, and the second mixing cavity region (30) is radially extended along the longitudinal axis (T2) of the second sub-region, preferably radially extended in a conical shape, or / and the longitudinal axis (T1) of the first sub-region and the longitudinal axis (T2) of the second sub-region are arranged at an angle to each other.

13. The mixing apparatus according to claim 12, characterized in that, The at least one first inlet (44) is located in the region of the first mixing chamber region (28) with a smaller radius and the at least one first outlet (48) is located in the region of the first mixing chamber region (28) with a larger radius, or / and the at least one second inlet (46) is located in the region of the second mixing chamber region (30) with a smaller radius and the at least one second outlet (50) is located in the region of the second mixing chamber region (30) with a larger radius.

14. The mixing apparatus according to claim 12 or 13, characterized in that, The longitudinal axis (T1) of the first sub-region and the longitudinal axis (T2) of the second sub-region are at an angle to each other, such that the interval between the longitudinal axis (T1) of the first sub-region and the longitudinal axis (T2) of the second sub-region in the region with a smaller radius size in the first mixing cavity region (28) and the second mixing cavity region (30) is smaller than the interval between the longitudinal axis (T1) of the first sub-region and the longitudinal axis (T2) of the second sub-region in the region with a larger radius size in the first mixing cavity region (28) and the second mixing cavity region (30).

15. The mixing apparatus according to any one of claims 9 to 14, with reference to claim 3, characterized in that, The longitudinal axis of the first sub-region (T1) and the longitudinal axis of the second sub-region (T2) are set substantially mirror-symmetrically about the opening plane (E1), or / and the longitudinal axis of the first sub-region (T1) and the longitudinal axis of the second sub-region (T2) are located in an axial plane (E2) that is substantially orthogonal to the opening plane (E1).

16. The mixing apparatus according to claim 3, or any one of claims 4 to 15 with reference to claim 3, characterized in that, The first mixing cavity region (28) and the second mixing cavity region (30) are substantially mirror-symmetrical about the opening plane (E1).

17. The mixing apparatus according to any one of claims 1 to 16, with reference to claim 9, characterized in that, -At least one guide extending locally about the longitudinal axis (T1) of the first sub-region is provided on the inner side of the wall region (32) defining the first sub-region (28) in the upstream direction of the wall of the upstream mixing chamber structural component (22), and / or on the inner side of the wall region (32) defining the first sub-region (28). -At least one guide extending locally about the longitudinal axis (T2) of the second sub-region is provided on the inner side of the wall region (34) defining the second sub-region (30) in the upstream direction of the wall of the upstream mixing chamber structural component (22), and / or on the inner side of the wall region (34) defining the second sub-region (30). -At least one guide (52) is provided on the inner side of the wall region (36) defining the first mixing chamber sub-region (28) in the downstream direction of the wall of the downstream mixing chamber structural component (24), extending locally about the longitudinal axis (T1) of the first sub-region, or / and - At least one guide (54) is provided on the inner side of the wall region (38) that defines the second mixing chamber sub-region (30) in the downstream direction of the wall (24) of the downstream mixing chamber structure component. It extends about the longitudinal axis of the second sub-region.

18. The mixing apparatus according to any one of claims 1 to 17, with reference to claim 9, characterized in that, -A guide (54; 64) is provided on the wall region (32) of the upstream mixing chamber structural component wall (22) defining the first mixing chamber sub-region (28) in the upstream direction, extending inward toward the exhaust gas guiding component (16) and defining at least one first inlet (44), or / and - A guide (58; 66) is provided on the wall region (34) of the second mixing chamber sub-region (30) in the upstream direction of the wall (22) of the upstream mixing chamber structure assembly, extending in the direction toward the inside of the exhaust gas guide assembly (16) and defining at least one second inlet (46).

19. An exhaust system for an internal combustion engine, the exhaust system comprising at least one exhaust treatment device (12) and a mixing device (14) upstream of the at least one exhaust treatment device (12) according to any one of claims 1 to 18.

Images