Light diesel tight-coupling SDPF high-efficiency flow-guiding distributed mixing device

Abstract

The application provides a light diesel tight-coupling SDPF high-efficiency flow-guiding distributed mixing device, the gas inlet end of the mixing device is connected with the gas outlet end of a DOC component, the gas outlet end of the mixing device is connected with the gas inlet end of an SDPF component, the DOC component and the SDPF component are arranged in a V shape; a nozzle base is arranged at the upper end of the mixing device, the nozzle base is used for mounting a urea nozzle, the urea nozzle is communicated with the inside of the mixing device; a flow guide plate is arranged in the inside of the mixing device, a dispersion breaking plate component is connected with the flow guide plate, and a cyclone plate is arranged at the outlet end of the mixing device. The mixing device can realize urea flow guiding and dispersion in a narrow space, improve the urea decomposition efficiency, realize the double-effect mixing effect of urea and soot, improve the uniformity of urea and soot distribution on the end surface of the SDPF, and prevent the urea from being directly injected to the bottom of the SDPF and deposited in the bottom in a compact space.

Description

A lightweight diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device Technical Field

[0001] This invention pertains to diesel engine exhaust aftertreatment, specifically relating to a light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device. Background Technology

[0002] SDPF (Self-Drug Processing Filter) is a dual-function aftertreatment approach that involves coating an SCR catalyst onto a DPF (Distillation Processing Filter). It is currently primarily used in purifiers for light-duty diesel vehicles. SDPF must meet the high NH3 mixing uniformity requirements of the SCR system to improve NOx conversion efficiency, and also the high flow rate uniformity and soot distribution uniformity requirements of the DPF system to reduce the risk of soot clogging and uneven regeneration. Furthermore, since even a small amount of urea crystallization can cause severe DPF clogging, it is essential to maximize the urea breakup and decomposition rate to minimize the crystallization risk in SDPF.

[0003] Light-duty diesel vehicles typically employ a tightly coupled purifier layout. Because the purifier is installed within the engine compartment, the limited space makes the mixing device design challenging. Measures commonly used in heavy-duty diesel vehicles, such as increasing the mixing distance and expanding the mixing cavity volume, are no longer feasible. In particular, ensuring uniform soot distribution, urea mixing uniformity, and urea fragmentation within a compact layout is a major challenge in the development of SDPF tightly coupled purifiers. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a high-efficiency flow-guiding and dispersing mixing device for light-duty diesel tightly coupled SDPF. This mixing device can achieve urea flow-guiding and dispersion in confined spaces, improve urea decomposition efficiency, achieve a dual-effect mixing of urea and soot, improve the uniformity of urea and soot distribution on the SDPF end face, and prevent urea from being directly sprayed to the bottom of the SDPF and depositing therein in a compact space.

[0005] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows:

[0006] A light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersion mixing device, wherein the air inlet of the mixing device is connected to the air outlet of the DOC component, and the air outlet of the mixing device is connected to the air inlet of the SDPF component, and the DOC component and SDPF component are arranged in a V-shape.

[0007] The upper end of the mixing device is provided with a nozzle base, which is used to install a urea nozzle, and the urea nozzle is in communication with the interior of the mixing device.

[0008] The mixing device is equipped with a guide plate inside, and a dispersing and crushing plate assembly is connected to the guide plate. A swirl plate is provided at the outlet end of the mixing device.

[0009] Furthermore, the mixing device includes an outer shell of the mixing chamber and an inner shell of the mixing chamber, the upper part of the outer shell of the mixing chamber is provided with a concave plane, and the nozzle base is disposed on the concave plane.

[0010] Furthermore, the installation angle α of the nozzle base satisfies the following condition: the urea spray entering the mixing device from the urea nozzle adheres to the wall at the center of the front face of the SDPF assembly.

[0011] Furthermore, the guide plate is disposed on the outer shell of the mixing chamber, and the angle γ between the guide plate and the outer shell of the mixing chamber is 20° to 60°. The angle of the guide plate ensures that the urea entering from the urea nozzle is distributed in the upper half of the SDPF assembly.

[0012] Furthermore, the guide plate has a semi-circular design, with the front and rear sides rolled up towards the middle, guiding the airflow to converge towards the top and center of the mixing device.

[0013] Furthermore, the dispersed fragment assembly includes two parallel fragments arranged in an inverted "V" shape;

[0014] The dispersion and crushing disc is provided with crushing blades, and the crushing blades are turned outward.

[0015] Furthermore, the swirl plate is provided with large flanged blades, small flanged blades, and uniformly distributed air holes; the flanged direction of the large flanged blades and the small flanged blades is the same as the airflow direction.

[0016] Furthermore, a flow guide notch is provided on the lower end cylinder of the DOC component outlet, the flow guide notch is located at the front end of the dispersion and crushing disc assembly, and the dispersion and crushing disc assembly is located at the front end of the swirl plate.

[0017] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0018] 1. Based on the characteristics of the light-duty diesel vehicle tightly coupled purifier, the DOC section and SDPF section at both ends of the light-duty diesel tightly coupled SDPF high-efficiency flow-guiding and decentralized mixing device of the present invention are arranged in a compact V-shape, which can greatly reduce the space occupied, reduce temperature loss, and improve the average exhaust temperature of SDPF.

[0019] 2. The lower end of the DOC component cylinder at the front end of the mixing device of this invention is designed with a flow guide notch. This maximizes the airflow mixing space in the upper half of the SDPF component, facilitating early airflow redirection and improving the uniformity of airflow distribution in the upper half of the SDPF component. Simultaneously, this flow guide notch design prevents the lower end of the DOC component cylinder from being too close to the SDPF component, thus preventing obstruction of the urea spray's expansion and dispersion on the SDPF end face. It also allows for maximum adjustment of the urea injection angle by adjusting the nozzle base mounting angle α.

[0020] 3. The nozzle base of the mixing device of the present invention is designed on the concave plane of the outer shell of the mixing chamber, and the installation angle α of the nozzle base is adjusted by changing the angle of the concave plane, thereby ensuring that the urea spray is attached to the wall at the center of the front end face of the SDPF.

[0021] 4. Due to space constraints in the engine compartment, the DOC and SDPF assemblies are arranged in a V-shape, with the nozzle base positioned at the upper end of the mixing chamber. This causes airflow and urea to tend to accumulate at the lower end of the SDPF assembly, resulting in lower flow velocity and urea concentration in the upper half of the SDPF assembly. To improve the flow velocity and urea concentration in the upper half of the SDPF, a semi-annular deflector is designed, with both sides rolled up towards the center. This allows airflow to converge towards the center of the mixing chamber, improving the uniform distribution of urea and airflow on the SDPF end face.

[0022] 5. The mixing device of the present invention has two rows of crushing blades below the guide plate. The crushing blades are in an inverted "V" shape, and crushing blades are arranged on both sides of the crushing blades. The 6 to 10 crushing blades on each side are rotated in an alternating manner. The two rows of crushing blades are arranged in parallel to split the airflow a second time and disperse the urea to both sides, so as to realize the rapid crushing, decomposition and dispersion of urea.

[0023] 6. In order to ensure the uniform distribution of airflow and NH3 from urea decomposition on the front end face of the SDPF, a swirl plate is installed below the guide plate to remix the broken urea, NH3 from urea decomposition, and airflow through the cavity swirl, thereby improving the uniformity of airflow and NH3 on the SDPF end face.

[0024] 7. Because commonly used urea nozzles on the market generally have a high initial spray speed (25m / s~45m / s) to improve atomization, and the mixing chamber of the light diesel tightly coupled SDPF is relatively small, the rapidly injected urea can easily be sprayed directly to the bottom of the SDPF mixing chamber, leading to urea accumulation and crystallization at the bottom of the SDPF, affecting the uniformity of NH3. The high-efficiency flow-guiding and dispersing mixing device described in this invention can achieve efficient flow guidance and rapid crushing, dispersion, and decomposition of urea, minimizing urea deposition at the bottom of the mixing chamber. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the application of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0026] Figure 2 is a schematic diagram of the application of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0027] Figure 3 is an exploded schematic diagram of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0028] Figure 4 is a cross-sectional view of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0029] Figure 5 is an exploded view of the application of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0030] Figure 6 is an exploded schematic diagram of the light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device of the present invention.

[0031] Figure 7 is a schematic diagram of the guide plate and dispersion / crushing plate assembly in the mixing device of Figure 1 of the present invention.

[0032] Figure 8 is a schematic diagram of the dispersion and crushing plate assembly in the mixing device of Figure 1 of the present invention.

[0033] Figure 9 is a schematic diagram of the swirl plate in the mixing device of Figure 1 of the present invention.

[0034] Figure reference numerals: 1-DOC assembly; 2-nozzle base; 3-mixing device; 4-connecting bolt assembly; 5-SDPF assembly; 6-support; 1-1-guide notch; 3-1-outer shell of mixing chamber; 3-2-inner shell of mixing chamber; 3-3-guide plate; 3-4-breaker plate; 3-5-swirl plate; 350-large flanged blade; 351-small flanged blade; 352-pore. Detailed Implementation

[0035] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention.

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] Example 1

[0038] As shown in Figures 1-6, a light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device is provided. The air inlet of the mixing device 3 is connected to the air outlet of the DOC component 1, and the air outlet of the mixing device 3 is connected to the air inlet of the SDPF component 5. The DOC component 1 and the SDPF component 5 are arranged in a V-shape.

[0039] The upper end of the mixing device 3 is provided with a nozzle base 2, which is used to install a urea nozzle. The urea nozzle is connected to the interior of the mixing device 3.

[0040] As shown in Figure 7, the mixing device 3 is equipped with a guide plate 3-3 inside, and a dispersing and crushing plate assembly is connected to the guide plate 3-3. A swirl plate 3-5 is provided at the outlet end of the mixing device 3.

[0041] In one embodiment, the mixing device 3 is connected to the DOC assembly 1 by welding, and is also connected to the SDPF assembly 5 by the connecting bolt assembly 4, on which a bracket 6 is provided.

[0042] The mixing device 3 includes an outer shell 3-1 and an inner shell 3-2 for the mixing chamber. The upper part of the outer shell 3-1 has a concave plane, and the nozzle base 2 is disposed on the concave plane. The outer shell 3-1 and the inner shell 3-2 are welded together to form the entire mixing chamber.

[0043] The installation angle α of the nozzle base 2 satisfies the following condition: the urea spray entering the mixing unit 3 from the urea nozzle adheres to the wall at the center of the front face of the SDPF assembly 5. Specifically, the arrangement of the nozzle base 2 is determined based on the specific positions of the DOC assembly 1 and the SDPF assembly 5, as well as the spray cone angle β of the urea nozzle used.

[0044] The guide plate 3-3 is set on the outer shell 3-1 of the mixing chamber, and the angle γ between the guide plate 3-3 and the outer shell 3-1 of the mixing chamber is 20° to 60°. The setting angle of the guide plate 3-3 ensures that the urea entering from the urea nozzle 2 is distributed in the upper half of the SDPF assembly 5.

[0045] The guide plate 3-3 has a semi-circular design, with the front and rear sides rolled up towards the middle, guiding the airflow to converge towards the top and center of the mixing device 3.

[0046] As shown in Figure 8, the dispersed crushing disc assembly includes two parallel crushing discs 3-4, which are arranged in an inverted "V" shape.

[0047] The dispersing and breaking disc 3-4 is equipped with 6-10 breaking blades, with the breaking blades turned outwards. Two rows of breaking blades are arranged in parallel to split the airflow a second time and disperse the urea to both sides, thereby achieving rapid crushing, decomposition and dispersion of urea.

[0048] As shown in Figure 9, the swirl plate 3-5 is provided with a large flanged blade 350, a small flanged blade 351 and uniformly distributed air holes 352; the flanged direction of the large flanged blade 350 and the small flanged blade 351 is the same as the airflow direction.

[0049] The large flanged blade 350 is located on the outer ring, the small flanged blade 351 is located on the inner ring, and the pores 352 are evenly distributed between the large flanged blade 350 and the small flanged blade 351.

[0050] A flow guide notch 1-1 is provided on the lower end cylinder of the outlet of DOC component 1. The flow guide notch 1-1 is located at the front end of the dispersion and crushing disc assembly, which is located at the front end of the swirl plate 3-5.

[0051] Work process:

[0052] When the airflow enters the mixing device 3 through the DOC assembly 1, due to the inertia of the airflow, part of the airflow transitions to the lower half of the front face of the SDPF assembly 5 through the guide 3-1 of the outer shell of the mixing chamber, while the other part smoothly transitions to the upper half of the front face of the SDPF assembly 5 through the guide notch 1-1 at the lower end of the DOC assembly 1 cylinder. The guide notch 1-1 on the DOC assembly 1 increases the airflow mixing space in the upper half of the SDPF, facilitating the early turning of the airflow and improving the uniformity of airflow distribution in the upper half of the SDPF assembly 5. At the same time, the guide notch 1-1 can maximize the elevation of the urea jet, improve the urea distribution on the front face of the SDPF assembly 5, and prevent urea from being sprayed onto the DOC assembly 1.

[0053] Under the influence of inertial force, the airflow entering the mixing device 3 flows along the wall of the outer shell 3-1 of the mixing chamber towards the lower end face of the SDPF assembly 5. Upon passing the guide plate 3-3, the flow direction changes, and the airflow converges towards the upper and central positions of the mixing chamber under the guidance of the guide plate 3-3. At this time, urea is injected into the mixing device 3 from the nozzle base 2. The injected urea, under the influence of the guide plate 3-3 and the airflow lifted by the guide plate 3-3, converges towards the upper part of the mixing chamber, effectively preventing urea deposition at the bottom of the mixing chamber. Simultaneously, the urea jet is broken up and diverted to both sides on the dispersing and breaking disc 3-4, preventing excessive concentration of urea.

[0054] The urea and airflow, which are broken and dispersed by the dispersing and breaking blades 3-4, form a strong swirling flow after passing through the swirl plate 3-5, which improves the uniformity of the distribution of airflow and urea on the front end of the SDPF component 5, thereby ensuring the uniform distribution of airflow, NH3 and soot.

[0055] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A lightweight diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device, characterized in that, The air inlet of the mixing device (3) is connected to the air outlet of the DOC component (1), and the air outlet of the mixing device (3) is connected to the air inlet of the SDPF component (5). The DOC component (1) and the SDPF component (5) are arranged in a V-shape. A nozzle base (2) is provided at the upper end of the mixing device (3). The nozzle base (2) is used to install a urea nozzle. The urea nozzle is connected to the interior of the mixing device (3). A guide plate (3-3) is provided inside the mixing device (3). A dispersion and crushing disc assembly is connected to the guide plate (3-3). A swirl plate (3-5) is provided at the outlet end of the mixing device (3). The mixing device (3) includes an outer shell (3-1) of the mixing chamber and an inner shell (3-2) of the mixing chamber. The upper part of (3-1) is provided with a concave plane, and the nozzle base (2) is provided on the concave plane; the guide plate (3-3) is provided on the outer shell (3-1) of the mixing chamber, and the angle γ between the guide plate (3-3) and the outer shell (3-1) of the mixing chamber is 20° to 60°. The setting angle of the guide plate (3-3) ensures that the urea entering from the urea nozzle is distributed in the upper half of the SDPF assembly (5); the guide plate (3-3) is designed in a semi-ring shape, with the front and rear sides rolled up towards the middle, guiding the airflow to converge towards the upper and central position of the mixing device (3); the dispersion and crushing plate assembly includes two parallel crushing plates (3-4), and the crushing plates (3-4) are arranged in an inverted "V" shape; the crushing plates (3-4) are provided with crushing blades, and the crushing blades are turned outward.

2. The light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device according to claim 1, characterized in that, The installation angle α of the nozzle base (2) satisfies the following condition: the urea spray entering the mixing device (3) from the urea nozzle adheres to the wall at the center of the front end face of the SDPF assembly (5).

3. The light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device according to claim 1, characterized in that, The swirl plate (3-5) is provided with large flanged blades (350), small flanged blades (351) and uniformly distributed air holes (352); the flanged direction of the large flanged blades (350) and the small flanged blades (351) is the same as the airflow direction.

4. The light diesel tightly coupled SDPF high-efficiency flow-guiding and dispersive mixing device according to claim 1, characterized in that, The lower end cylinder of the DOC component (1) is provided with a flow guide notch (1-1), the flow guide notch (1-1) is located at the front end of the dispersion and crushing disc assembly, and the dispersion and crushing disc assembly is located at the front end of the swirl plate (3-5).

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