SCR MIXER AND VEHICLE
Patent Information
- Application Number
- DE112022006057
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-12-22
- Filing Date
- 2022-07-04
- Publication Date
- 2025-03-06
AI Technical Summary
It is difficult for existing vehicle after-treatment systems to solve the problems of urea crystallization and substandard NOX emissions, especially when the particle size of the urea spray is too large and the urea particles are not fully mixed with the exhaust gas.
An SCR mixer is designed. By arranging a urea collision component on the urea injection path, the urea solution is impacted and broken, and then mixed with high-temperature exhaust gas. The flow path is adjusted using a flow guide device to ensure full mixing and evaporation decomposition of urea and exhaust gas. , avoid crystallization and improve the mixing uniformity of NH3.
It effectively avoids the problem of urea crystallization, improves the mixing uniformity and evaporation decomposition efficiency of urea and exhaust gas, and ensures the reduction of NOX emissions.
Smart Images
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Abstract
Description
SCR mixer and vehicle
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This application is based on the Chinese patent application with application number 202111583100.8 and application date of December 22, 2021, and claims the priority benefit of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated by reference into this application. Technical Field
[0003] The present application belongs to the field of vehicle technology, and in particular relates to an SCR mixer and a vehicle having the SCR mixer. Background Art
[0004] This section merely provides background information related to the present disclosure and is not necessarily prior art.
[0005] SCR selective catalytic reduction technology is a technology to reduce NO X However, urea crystallization and NO X Substandard emissions have always been a difficult problem for SCR technology to solve. Eliminating or reducing urea crystallization requires reducing the urea spray particle size and ensuring that the urea particles mix thoroughly with the exhaust gas and evaporate and decompose. Current vehicle aftertreatment systems struggle to address this issue.
[0006] Summary of the Invention
[0007] The purpose of this application is to at least solve the problem of urea crystallization in SCR mixers. This purpose is achieved through the following technical solutions:
[0008] The first aspect of the present application provides an SCR mixer, comprising:
[0009] a cylinder, wherein the cylinder is provided with an air inlet, an exhaust port, and a urea injection port, wherein the air inlet and the exhaust port are respectively provided at two ends of the cylinder in the axial direction, and the urea injection port is provided on a radial side wall of the cylinder and close to the air inlet;
[0010] a urea collision assembly, the urea collision assembly being disposed inside the cylinder and corresponding to the urea injection port, such that the urea collision assembly is located on a urea injection path;
[0011] A flow guide device is arranged inside the cylinder and close to the exhaust port, and is used to adjust the flow path of the mixed gas containing urea in the cylinder so that the flow path includes a forward flow portion flowing toward the exhaust port and a reverse flow portion flowing toward the air inlet.
[0012] According to the SCR mixer of the present invention, a urea collision assembly is provided in the urea injection path. Urea solution injected from the urea injection port impacts the urea collision assembly, causing some urea droplets to rebound and break up before mixing with the high-temperature exhaust / tail gas. The urea droplets are then forwarded into the diversion device under the action of the airflow. Some urea droplets are deposited on the surface of the urea collision assembly, then swept away by the airflow and transported along with the airflow into the diversion device. Guided by the diversion device, the urea-containing mixed gas flows through a sufficiently long path within the mixer in a zigzag manner, ensuring sufficient time for the urea and exhaust gas to fully mix, evaporate, and decompose. This prevents urea crystallization in the SCR mixer and significantly improves the uniformity of NH3 mixing.
[0013] In some embodiments of the present application, the urea collision assembly includes a plurality of baffles distributed along the radial direction of the cylinder, and areas of the plurality of baffles gradually increase in a direction away from the urea injection port.
[0014] In some embodiments of the present application, at least a portion of the plurality of baffles include a first baffle portion parallel to the central axis of the cylinder and a second baffle portion angled with the central axis of the cylinder.
[0015] In some embodiments of the present application, the second blocking piece is extended from one end of the first blocking piece portion in a direction away from the urea injection port.
[0016] In some embodiments of the present application, the flow guide device includes a first flow guide member and a second flow guide member, and the first flow guide member, the second flow guide member and the cylinder are coaxial, wherein:
[0017] The first flow guide is provided with a closed curved surface end and an open end which are arranged opposite to each other in the axial direction, the open end faces the second flow guide, and a first flow guide channel is formed between the outer peripheral surface of the first flow guide and the inner wall of the cylinder;
[0018] The second flow guide member is provided with a first opening and a second opening which are arranged opposite to each other in the axial direction, the first opening facing the first flow guide member, and the diameter of the first opening is smaller than the diameter of the opening end, so that a portion of the second flow guide member extends into the first flow guide member through the opening end to form a second flow guide channel between the inner circumferential surface of the first flow guide member and the outer circumferential surface of the second flow guide member, and the second opening is connected to the inner wall of the cylinder.
[0019] In some embodiments of the present application, the first flow guide member includes a first axial extension portion, one end of the first axial extension portion is connected to the closed curved surface end, and the other end forms the open end.
[0020] In some embodiments of the present application, the second flow guide member includes a second axial extension portion and a curved surface portion, one end of the second axial extension portion forms the first opening, and the other end is connected to the curved surface portion, the end of the curved surface portion away from the second axial extension portion forms the second opening, and the second flow guide channel is formed between the second axial extension portion and the first axial extension portion.
[0021] In some embodiments of the present application, the flow guide device also includes a swirl assembly, which includes a plurality of blades, and the plurality of blades are arranged in a ring inside the cylinder. The plurality of blades are respectively connected to the first flow guide member and / or connected to the inner wall of the cylinder. At least a portion of the blades is located in the first flow guide channel, and any one of the blades is inclined relative to the central axis of the first flow guide member.
[0022] In some embodiments of the present application, the SCR mixer further includes a temperature sensor. The cylinder is provided with a temperature sensor mounting hole for mounting the temperature sensor. The temperature sensor mounting hole is provided closer to the air inlet than the urea injection port.
[0023] Another aspect of the present application further provides a vehicle, comprising any of the above-mentioned SCR mixers.
[0024] The vehicle according to the embodiment of the present application has the same advantages as the above-mentioned SCR mixer, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:
[0026] FIG1 is a schematic diagram of the internal structure of an SCR mixer according to an embodiment of the present application;
[0027] FIG2 is a schematic diagram of the internal structure of the SCR mixer according to an embodiment of the present application from another angle;
[0028] FIG3 is a schematic diagram of the external structure of an SCR mixer according to an embodiment of the present application;
[0029] FIG4 is a schematic diagram of the end structure of the flow guide device of the SCR mixer according to an embodiment of the present application.
[0030] The symbols in the accompanying drawings represent the following:
[0031] 1. Cylinder; 11. Air inlet; 12. Exhaust port; 13. Urea injection port; 14. Temperature sensor mounting hole;
[0032] 2. Urea collision assembly; 21. Blocking piece; 211. First blocking piece portion; 212. Second blocking piece portion;
[0033] 3. Flow guide device; 31. First flow guide member; 32. Second flow guide member; 33. Swirl assembly; 311. Curved closed end; 312. Open end; 313. First axial extension; 321. First opening; 322. Second opening; 323. Second axial extension; 324. Curved surface; 331. Blade;
[0034] 4. The first diversion channel;
[0035] 5. The second diversion channel. DETAILED DESCRIPTION
[0036] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.
[0037] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, as used herein, the singular forms "a," "an," and "the" may also be intended to include the plural forms. The terms "comprise," "include," "contain," and "have" are inclusive and, therefore, specify the presence of the stated features, steps, operations, elements, and / or parts, but do not preclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof.
[0038] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.
[0039] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "below" another element or feature would then be oriented as "above" or "above" another element or feature. Thus, the example term "below" may include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein are interpreted accordingly.
[0040] As shown in FIG1 to FIG4 , the SCR mixer according to the present application includes:
[0041] The cylinder 1 is provided with an air inlet 11, an exhaust port 12 and a urea injection port 13. The air inlet 11 and the exhaust port 12 are respectively provided at both ends of the cylinder 1 in the axial direction. The urea injection port 13 is provided on the radial side wall of the cylinder 1 and is close to the air inlet 11.
[0042] A urea collision assembly 2 is disposed inside the cylinder 1 and corresponds to the urea injection port 13 , so that the urea collision assembly 2 is located on the urea injection path;
[0043] The flow guiding device 3 is arranged inside the cylinder 1 and close to the exhaust port 12. The flow guiding device 3 is used to adjust the flow path of the mixed gas containing urea in the cylinder 1 so that the flow path includes a forward flow portion flowing toward the exhaust port 12 and a reverse flow portion flowing toward the air inlet 12.
[0044] By placing the urea injection assembly 2 within the urea injection path, the urea solution injected from the urea injection port 13 impacts the urea collision assembly 2, causing some urea droplets to rebound and break up before mixing with the high-temperature exhaust / tail gas. These droplets are then transported forward by the airflow into the flow guide 3. Some urea droplets deposit on the surface of the urea collision assembly before being swept away by the airflow and swept into the flow guide 3. Guided by the flow guide 3, the urea-containing mixed gas flows through a sufficiently long path within the mixer in a zigzag pattern, ensuring ample time for the urea and exhaust gas to fully mix, evaporate, and decompose. This prevents urea crystallization in the mixer and significantly improves the uniformity of NH3 mixing.
[0045] In some embodiments of the present application, as shown in FIG. 1 to FIG. 3 , the urea collision assembly 2 includes a plurality of baffles 21 distributed along the radial direction of the cylinder, and the area of each baffle 21 gradually increases in a direction away from the urea injection port 13 .
[0046] In the embodiment shown in Figures 1 and 2, the urea collision assembly 2 includes four baffles 21 located below the urea injection port 13. The four baffles 21 are arranged in a stair-like pattern along the radial and vertical directions of the barrel 1, i.e., their area gradually increases as they move away from the urea injection port 13 (from top to bottom). This arrangement allows the urea solution injected into the barrel 1 through the urea injection port 13 to collide with the baffles 21 at multiple locations, facilitating the dispersion of the urea droplets and their thorough mixing with the exhaust gas.
[0047] In some embodiments of the present application, as shown in Figures 1 to 3, at least a portion of the plurality of baffles 21 includes a first baffle portion 211 parallel to the central axis of the cylinder and a second baffle portion 212 angled with the central axis of the cylinder. Furthermore, the second baffle portion 212 extends from one end of the first baffle portion 211 in a direction away from the urea injection port 13.
[0048] By providing the first baffle portion 211 and the second baffle portion 212, the urea droplets after the collision can be rebounded in different directions, thereby improving the dispersion effect of the urea droplets and the mixing effect with the exhaust gas. In addition, the first baffle portion 211 can be provided with a connection portion connected to the barrel 1.
[0049] In some embodiments of the present application, as shown in Figures 1, 2, and 4, the flow guide device 3 includes a swirl assembly 33. The swirl assembly 33 includes a plurality of blades 331. The blades 331 are evenly distributed around the central axis of the cylinder 1, and each blade 331 is inclined relative to the central axis of the cylinder 1. Preferably, as shown in Figure 4, the swirl assembly 33 includes 12 evenly distributed blades 331. Further preferably, the angle between the blade surface extension direction of each blade 331 and the central axis of the cylinder 1 is between 30° and 70°.
[0050] By providing a swirl assembly 33 including a plurality of blades 331 , the urea droplets can be further dispersed under the action of the swirl, which helps to fully mix with the exhaust gas.
[0051] In some embodiments of the present application, as shown in FIG1 to FIG4 , the flow guide device 3 includes a first flow guide 31 and a second flow guide 32 , and the first flow guide 31 , the second flow guide 32 and the cylinder 1 are coaxial, wherein:
[0052] The first flow guide 31 is provided with a closed curved end 311 and an open end 312 in opposite axial directions. The open end 312 faces the second flow guide 32. A first flow guide channel 4 is formed between the outer circumference of the first flow guide 31 and the inner wall of the cylinder 1.
[0053] The second flow guide member 32 is provided with a first opening 321 and a second opening 322 which are arranged opposite to each other in the axial direction. The first opening 321 faces the first flow guide member 31. The diameter of the first opening 321 is smaller than the diameter of the opening end 312 of the first flow guide member 31, so that a portion of the second flow guide member 32 extends into the first flow guide member 31 through the opening end 312 to form a second flow guide channel 5 between the inner circumferential surface of the first flow guide member 31 and the outer circumferential surface of the second flow guide member 32. The second opening 322 is connected to the inner wall of the cylinder 1.
[0054] The mixed gas containing urea droplets enters the first guide channel 4 through the swirl assembly 33, flows forward toward the exhaust port 12, then enters the second guide channel 5 and flows in the opposite direction toward the intake port 11. When it reaches the closed curved end 311, the airflow turns and exits the SCR mixer through the second opening 322 and the exhaust port 12. The airflow is turned back on both sides by the first and second guide members 31, 32, increasing the airflow path and ensuring thorough mixing of the urea and exhaust gas, as well as evaporation and decomposition.
[0055] In some embodiments of the present application, as shown in FIG. 1 and FIG. 2 , the first flow guide 31 includes a first axial extension portion 313 , one end of the first axial extension portion 313 is connected to the closed curved surface end 311 , and the other end forms an open end 312 .
[0056] In some embodiments of the present application, as shown in Figures 1 and 2, the second flow guide member 32 includes a second axial extension portion 323 and a curved surface portion 324, one end of the second axial extension portion 323 forms a first opening 321, and the other end is connected to the curved surface portion 324, an end of the curved surface portion 324 away from the second axial extension portion forms a second opening 322, and a second flow guide channel 5 is formed between the second axial extension portion 323 and the first axial extension portion 313.
[0057] The mixed gas containing urea makes a first turn when it reaches the curved surface portion 324 through the first guide channel 4, then enters the second guide channel 5, and makes a second turn when it reaches the curved closed end 311. Setting a curved surface structure at the airflow turning position helps the mixed gas flow smoothly and can prevent urea particles from remaining on the surface of the component.
[0058] In some embodiments of the present application, as shown in Figures 1, 2, and 4, each blade 331 of the swirl assembly 33 is respectively connected to the first guide member 31 and is evenly distributed on the first guide member 31, so that at least a portion of each blade 331 is located in the first guide channel 4.
[0059] Through this arrangement, the internal space of the SCR mixer can be utilized to the greatest extent while ensuring the mixing effect of urea and mixed gas.
[0060] In other embodiments thereof, each blade 331 of the swirl assembly 33 may also be connected to the inner wall of the cylinder 1 , or simultaneously connected to the inner wall of the cylinder 1 and the outer wall of the first flow guide 31 , thereby fixing the first flow guide 31 inside the cylinder 1 .
[0061] In some embodiments of the present application, the SCR mixer further includes a temperature sensor. As shown in Figures 1 to 3, a temperature sensor mounting hole 14 is provided on the cylinder 1. The temperature sensor mounting hole 14 is provided closer to the air inlet 11 than the urea injection port 13. The temperature sensor is inserted into the temperature sensor mounting hole 14.
[0062] The temperature sensor is arranged closer to the air inlet 11 than the urea injection port 13 so as to monitor the temperature upstream of the SCR mixer and thus control the start time of urea injection.
[0063] Another embodiment of the present application provides a vehicle, comprising the SCR mixer according to any one of the above embodiments.
[0064] The vehicle according to the embodiment of the present application has the same advantages as the above-mentioned SCR mixer, which will not be described in detail here.
[0065] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.
Claims
1. An SCR mixer, characterized in that: include: a cylinder, wherein the cylinder is provided with an air inlet, an exhaust port, and a urea injection port, wherein the air inlet and the exhaust port are respectively provided at two ends of the cylinder in the axial direction, and the urea injection port is provided on a radial side wall of the cylinder and close to the air inlet; a urea collision assembly, the urea collision assembly being disposed inside the cylinder and corresponding to the urea injection port, such that the urea collision assembly is located on a urea injection path; A flow guide device is arranged inside the cylinder and close to the exhaust port, and is used to adjust the flow path of the mixed gas containing urea in the cylinder so that the flow path includes a forward flow portion flowing toward the exhaust port and a reverse flow portion flowing toward the air inlet.
2. The SCR mixer according to claim 1, characterized in that The urea collision assembly includes a plurality of baffles distributed along the radial direction of the cylinder, and the areas of the plurality of baffles gradually increase in a direction away from the urea injection port.
3. The SCR mixer according to claim 2, characterized in that At least a portion of the plurality of baffles includes a first baffle portion parallel to the central axis of the cylinder and a second baffle portion forming an angle with the central axis of the cylinder.
4. The SCR mixer according to claim 3, characterized in that The second blocking piece is extended from one end of the first blocking piece portion in a direction away from the urea injection port.
5. The SCR mixer according to claim 1, characterized in that The flow guide device includes a first flow guide member and a second flow guide member, wherein the first flow guide member, the second flow guide member and the cylinder are coaxial, wherein: The first flow guide is provided with a closed curved surface end and an open end which are arranged opposite to each other in the axial direction, the open end faces the second flow guide, and a first flow guide channel is formed between the outer peripheral surface of the first flow guide and the inner wall of the cylinder; The second flow guide member is provided with a first opening and a second opening which are arranged opposite to each other in the axial direction, the first opening facing the first flow guide member, and the diameter of the first opening is smaller than the diameter of the opening end, so that a portion of the second flow guide member extends into the first flow guide member through the opening end to form a second flow guide channel between the inner circumferential surface of the first flow guide member and the outer circumferential surface of the second flow guide member, and the second opening is connected to the inner wall of the cylinder.
6. The SCR mixer according to claim 5, characterized in that The first flow guide comprises a first axial extension portion, one end of the first axial extension portion is connected to the closed curved surface end, and the other end forms the open end.
7. The SCR mixer according to claim 6, characterized in that The second flow guide member includes a second axial extension portion and a curved surface portion, one end of the second axial extension portion forms the first opening, and the other end is connected to the curved surface portion, the end of the curved surface portion away from the second axial extension portion forms the second opening, and the second flow guide channel is formed between the second axial extension portion and the first axial extension portion.
8. The SCR mixer according to claim 5, characterized in that The flow guide device also includes a swirl assembly, which includes a plurality of blades. The plurality of blades are arranged in an annular manner inside the cylinder. The plurality of blades are respectively connected to the first flow guide member and / or the inner wall of the cylinder. At least a portion of the blades is located in the first flow guide channel, and any one of the blades is arranged to be inclined relative to the central axis of the first flow guide member.
9. The SCR mixer according to claim 1, characterized in that The SCR mixer further includes a temperature sensor. The cylinder is provided with a temperature sensor mounting hole for mounting the temperature sensor. The temperature sensor mounting hole is arranged closer to the air inlet than the urea injection port.
10. A vehicle, characterized in that: The SCR mixer comprises the SCR mixer according to any one of claims 1 to 9.