Urea double-spraying tail gas treatment device and vehicle

Abstract

The utility model relates to a urea double-injection tail gas treatment device and a vehicle. The urea double-spraying tail gas treatment device comprises a front-end mixer, the front-end mixer comprises a first urea spraying inlet, a first gas inlet end, a first mixing piece and a first exhaust end, the first gas inlet end is used for being connected with an engine exhaust port, the first urea spraying inlet is formed in the side wall of the front-end mixer, and the first mixing piece is arranged on the side wall of the front-end mixer; the first mixing part is opposite to the first urea spray inlet, and the first exhaust end is provided with a first flow guide part; the rear-end mixer comprises a second urea spray inlet, a second air inlet end, a second mixing piece and a second air exhaust end, the second air inlet end is connected with the first air exhaust end, the second urea spray inlet is formed in the side wall of the rear-end mixer, the second mixing piece and the second urea spray inlet are oppositely arranged, and the second air exhaust end is communicated with the atmosphere. According to the urea double-injection tail gas treatment device and the vehicle, the conversion efficiency of nitric oxide in tail gas can be improved.

Description

Technical Field

[0001] This utility model relates to the field of vehicle exhaust gas treatment technology, and in particular to a urea dual-injection exhaust gas treatment device and vehicle. Background Technology

[0002] During the actual combustion process of motor vehicle fuel, the combustion process is incomplete due to factors such as combustion temperature, oxygen concentration, and fuel purity, generating various harmful byproducts such as particulate matter, nitrogen oxides, and carbon monoxide. Nitrogen oxides mainly include nitric oxide and nitrogen dioxide. Nitrogen oxides not only harm human health but also cause photochemical smog pollution and damage the ecological environment. Therefore, controlling nitrogen oxide emissions from motor vehicles is of paramount importance for improving air quality and protecting the ecological environment.

[0003] In existing technologies, three-way catalytic converters or selective catalytic reduction (SCR) technology are commonly used to control nitrogen oxide emissions from motor vehicles. SCR refers to the use of reducing agents such as urea aqueous solution, under the action of a catalyst, to reduce nitrogen oxides into harmless nitrogen and water, while minimizing the reaction between the reducing agent and oxygen, thus achieving selective reduction and reducing nitrogen oxide emissions in vehicle exhaust. Existing single-stage urea injection systems primarily calibrate their injection volume based on steady-state conditions. Under transient conditions, the exhaust flow rate increases significantly, and the high-speed airflow can easily lead to insufficient mixing and urea crystallization, resulting in low conversion efficiency. Utility Model Content

[0004] Therefore, it is necessary to provide a urea dual-injection exhaust gas treatment device and vehicle that can improve the conversion efficiency of nitrogen oxides in exhaust gas, in order to address the above problems.

[0005] In a first aspect, a urea dual-injection tail gas treatment device is provided, comprising:

[0006] A front-end mixer includes a first urea spray inlet, a first air intake end, a first mixing component, and a first exhaust end. The first air intake end is used to connect to the engine exhaust port. The first urea spray inlet is opened on the side wall of the front-end mixer. The first mixing component is disposed opposite to the first urea spray inlet. The first exhaust end is provided with a first guide component.

[0007] The back-end mixer includes a second urea spray inlet, a second air inlet, a second mixing element, and a second exhaust end. The second air inlet is connected to the first exhaust end. The second urea spray inlet is located on the side wall of the back-end mixer. The second mixing element is disposed opposite to the second urea spray inlet. The second exhaust end is open to the atmosphere.

[0008] In one embodiment, the first mixing component includes a first irregularly shaped perforated plate, a first breaking perforated plate, and a second irregularly shaped perforated plate arranged in parallel in sequence. The first irregularly shaped perforated plate, the breaking perforated plate, and the second irregularly shaped perforated plate at least partially overlap with the projection of the first urea spray inlet on the axial direction of the first urea spray inlet, and the first irregularly shaped perforated plate, the breaking perforated plate, and the second irregularly shaped perforated plate are arranged at an angle relative to the axial direction of the first urea spray inlet.

[0009] The second mixing component includes a third irregularly shaped orifice plate, a second breaking orifice plate, and a fourth irregularly shaped orifice plate arranged in parallel. The third irregularly shaped orifice plate, the second breaking orifice plate, and the fourth irregularly shaped orifice plate at least partially overlap with the projection of the second urea spray inlet on the axial direction of the second urea spray inlet, and the third irregularly shaped orifice plate, the second breaking orifice plate, and the fourth irregularly shaped orifice plate are arranged at an angle relative to the axial direction of the second urea spray inlet.

[0010] In one embodiment, the first guide member is a tapered guide plate, and the tapered guide plate has multiple guide holes.

[0011] In one embodiment, the diameter of the flow guide hole is less than or equal to 6 mm.

[0012] In one embodiment, the angles between the first and second shaped orifice plates and the axial direction of the first urea spray inlet are different from the angles between the third and fourth shaped orifice plates and the axial direction of the second urea spray inlet.

[0013] In one embodiment, the first, second, third, and fourth irregularly shaped perforated plates are each provided with a plurality of irregularly shaped holes, and a guide plate is inclined on one side of each irregularly shaped hole. The multiple guide plates on the same irregularly shaped perforated plate are inclined in the same direction.

[0014] In one embodiment, the front-end mixer further includes a first arc-shaped guide plate, the first end of which is connected to the inner wall of the front-end mixer; the rear-end mixer further includes a second arc-shaped guide plate, one end of which is connected to the inner wall of the front-end mixer.

[0015] In one embodiment, the inner diameter of the front-end mixer is smaller than the inner diameter of the back-end mixer.

[0016] In one embodiment, a connecting section is provided between the front-end mixer and the back-end mixer, the inner diameter of the connecting section being smaller than the inner diameter of the back-end mixer.

[0017] In a second aspect, a vehicle is provided, including a urea dual-injection exhaust gas treatment device as described in the first aspect or any embodiment of the first aspect.

[0018] The aforementioned urea dual-injection exhaust gas treatment device and vehicle are equipped with urea spray inlets in both the front-end and rear-end mixers. This allows the front-end mixer to preliminarily treat nitrogen oxides in the high-temperature exhaust gas, while the rear-end mixer can replenish the incompletely reacted exhaust gas from the front end with urea spray. Compared to a single-stage mixer, the urea spray has a longer contact time with the exhaust gas, resulting in a more complete reaction and improved conversion of nitrogen oxides in the exhaust gas. Furthermore, the device can adapt to dynamic changes in operating conditions by adjusting the urea injection volume at the first and second urea spray inlets. The first and second mixing components are respectively positioned opposite the first and second urea spray inlets, allowing the urea spray to be impacted and broken into smaller droplets upon impact with the surface of the mixing components, increasing the contact area between the urea spray and the exhaust gas. The mixing components can also turbulent the airflow, ensuring thorough mixing of the urea droplets with the nitrogen oxides in the exhaust gas, accelerating the selective catalytic reduction reaction, and improving the conversion rate of nitrogen oxides. The first guide component located at the first exhaust end can rectify the airflow after front-end mixing, improving the uniformity of the gas entering the rear-end mixer. Therefore, the urea dual-injection exhaust gas treatment device and vehicle provided in this application can improve the conversion efficiency of nitrogen oxides in exhaust gas. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view of a urea dual-injection tail gas treatment device provided in an embodiment of the present invention;

[0021] Figure 2 A perspective view of a urea dual-injection tail gas treatment device provided in an embodiment of this utility model;

[0022] Figure 3 A schematic diagram of the internal structure of the front-end mixer of a urea dual-injection tail gas treatment device provided in an embodiment of this utility model;

[0023] Figure 4 A schematic diagram of the internal structure of the rear-end mixer of the urea dual-injection tail gas treatment device provided in an embodiment of this utility model;

[0024] Figure 5A simulation result diagram of the urea particle crushing effect of the front-end mixer of the urea dual-injection tail gas treatment device provided in an embodiment of this utility model;

[0025] Figure 6 The simulation result diagram shows the urea particle crushing effect of the rear mixer of the urea dual-injection tail gas treatment device provided in an embodiment of this utility model.

[0026] To make the above and other objects, features, advantages and embodiments of this utility model more apparent and understandable, the appended symbols are explained as follows:

[0027] 100, Front-end mixer; 110, First urea spray inlet; 120, First air intake end; 130, First exhaust end; 140, Conical guide plate; 141, Guide hole; 150, First arc-shaped guide plate; 200, First mixing component; 210, First irregularly shaped perforated plate; 220, Second irregularly shaped perforated plate; 300, Rear-end mixer; 310, Second urea spray inlet; 320, Second air intake end; 330, Second exhaust end; 340, Second arc-shaped guide plate; 400, Second mixing component; 410, Third irregularly shaped perforated plate; 420, Fourth irregularly shaped perforated plate; 510, Irregularly shaped hole; 520, Guide plate; 600, Connecting section. Detailed Implementation

[0028] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 of this utility model.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] With increasingly stringent environmental regulations, controlling vehicle exhaust emissions has become a core focus of technological research and development. This requires not only reducing emissions of pollutants such as nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO), but also quantitatively limiting ammonia leakage (NH3-slip). Traditional after-treatment technologies (such as single SCR systems and passive DPF regeneration) suffer from low efficiency and insufficient dynamic response under low-temperature conditions, making it difficult to meet the demands for high stability and ultra-low emissions across all operating conditions. Currently, mainstream technologies such as the SCR+DPF integrated solution have efficiency bottlenecks. The NOx conversion efficiency of a single-stage urea injection system (SCR) decreases significantly under transient conditions (especially during cold starts), and the risk of ammonia leakage increases with the injection volume. This invention addresses these problems by providing an exhaust gas treatment device comprising a two-stage SCR system, capable of achieving low-temperature emission control and reducing urea crystallization. Figure 1 This is a schematic diagram of the structure of a urea dual-injection tail gas treatment device provided in an embodiment of the present invention. (See attached diagram.) Figure 1 An embodiment of this utility model provides a urea dual-injection tail gas treatment device, comprising:

[0035] The front-end mixer 100 includes a first urea spray inlet 110, a first air intake end 120, a first mixing component 200, and a first exhaust end 130. The first air intake end 120 is used to connect to the engine exhaust port. The first urea spray inlet 110 is opened on the side wall of the front-end mixer 100. The first mixing component 200 is disposed opposite to the first urea spray inlet 110. The first exhaust end 130 is provided with a first guide component.

[0036] The back-end mixer 300 includes a second urea spray inlet 310, a second air inlet 320, a second mixing component 400, and a second exhaust end 330. The second air inlet 320 is connected to the first exhaust end 130. The second urea spray inlet 310 is opened on the side wall of the back-end mixer 300. The second mixing component 400 is disposed opposite to the second urea spray inlet 310. The second exhaust end 330 is open to the atmosphere.

[0037] The front-end mixer 100 is a mixer directly connected to the engine exhaust outlet, which can initially mix the high-temperature exhaust gas discharged from the engine with the urea spray. It may include a housing, with a first air inlet 120, a first urea spray inlet 110, and a first exhaust end 130 formed on the wall of the housing. The first mixing component 200 and the first guide component are disposed inside the housing. The first mixing component 200 and the second mixing component 400 are components used to make the urea spray and exhaust gas more fully contact and mix to promote the atomization and decomposition of urea, and may include structures such as perforated plates. The first guide component is used to guide the gas mixed by the front mixer 100 to flow smoothly and evenly to the rear mixer 300. It may include structures such as a guide plate 520, a guide pipe, and a gas flow distributor. The first guide component can reduce the flow deviation and eddy phenomenon from the front mixer 100 to the rear mixer 300, gather the gas flow and urea droplets towards the middle part of the flow channel, reduce the flow of gas flow to the edge area of ​​the catalyst, improve the uniformity of the gas flow entering the rear mixer 300, make the secondary reaction more complete, and thus make the urea reaction more complete, reduce crystallization, and more effectively reduce nitrogen oxides in the exhaust gas. Figure 2 and Figure 3 The figures show simulation results of the particle breaking effect of the front-end mixer 100 and the rear-end mixer 300 on the urea spray in the urea dual-spray aftertreatment device. As shown in the figure, the urea dual-spray tail gas treatment device can break the urea spray particles with an average particle size of 400μm into particles of 0.5-383μm, and most of the particles are smaller than 100μm, which greatly reduces the risk of crystallization and improves the uniformity of ammonia distribution.

[0038] The aforementioned urea dual-injection exhaust gas treatment device has urea spray inlets in both the front-end mixer 100 and the rear-end mixer 300. This allows the front-end mixer 100 to preliminarily treat nitrogen oxides in the high-temperature exhaust gas, while the rear-end mixer 300 can supplement the incompletely reacted exhaust gas from the front end with urea spray. Compared to a single-stage mixer, the contact time between the urea spray and the exhaust gas is longer, resulting in a more complete reaction and improved conversion of nitrogen oxides in the exhaust gas. Furthermore, the device can adapt to dynamic changes in operating conditions by adjusting the urea injection rates at the first urea spray inlet 110 and the second urea spray inlet 310. The first mixing element 2... The first urea spray inlet 110 and the second urea spray inlet 310 are respectively positioned opposite to the first urea spray inlet 110 and the second urea spray inlet 310. This allows the urea spray to be impacted and broken into finer droplets upon impact with the surface of the mixing component, increasing the contact area between the urea spray and the exhaust gas. The mixing component also turbulently influences the airflow, ensuring thorough mixing of the urea droplets with nitrogen oxides in the exhaust gas. This accelerates the selective catalytic reduction reaction and improves the conversion rate of nitrogen oxides. The first guide component located at the first exhaust end 130 rectifies the mixed airflow at the front end, improving the uniformity of the gas entering the rear mixer 300. Therefore, the above-mentioned dual-injection urea exhaust gas treatment device can improve the conversion efficiency of nitrogen oxides in the exhaust gas.

[0039] In an exemplary embodiment, the first mixing component 200 includes a first irregularly shaped orifice plate 210, a first breaking orifice plate, and a second irregularly shaped orifice plate 220 arranged in parallel. The first irregularly shaped orifice plate 210, the breaking orifice plate, and the second irregularly shaped orifice plate 220 at least partially overlap with the projection of the first urea spray inlet 110 in the axial direction of the first urea spray inlet 110, and the first irregularly shaped orifice plate 210, the breaking orifice plate, and the second irregularly shaped orifice plate 220 are inclined relative to the axial direction of the first urea spray inlet 110. The second mixing component 400 includes a third irregularly shaped orifice plate 410, a second breaking orifice plate, and a fourth irregularly shaped orifice plate 420 arranged in parallel. The third irregularly shaped orifice plate 410, the second breaking orifice plate, and the fourth irregularly shaped orifice plate 420 at least partially overlap with the projection of the second urea spray inlet 310 in the axial direction of the second urea spray inlet 310, and the third irregularly shaped orifice plate 410, the second breaking orifice plate, and the fourth irregularly shaped orifice plate 420 are inclined relative to the axial direction of the second urea spray inlet 310. Each of the irregularly shaped orifice plates is a plate-like structure with irregularly shaped holes to promote the mixing of exhaust gas and urea spray. These irregularly shaped holes can be gradually expanding holes, Venturi holes, or holes with irregular cross-sections. For example... Figures 3 to 4As shown, the irregularly shaped orifice plate can be an arc-shaped plate with the same or similar shape as the arc-shaped guide plate 520, and its openings can be rectangular or other shapes. The breaking orifice plate can be a plate-like structure with the same shape as the irregularly shaped orifice plate, but the diameter of the breaking orifice on it is smaller than that of the first irregularly shaped orifice plate 210 and the second irregularly shaped orifice plate 220, and the pore density is higher. The irregularly shaped orifice plate initially breaks down the urea droplets carried in the exhaust gas, reducing the particle size initially. When the droplets carried by the high-speed airflow pass through the breaking orifice, they are further broken into smaller particles, increasing the specific surface area of ​​the droplets. The combination of the first irregularly shaped orifice plate 210, the breaking orifice plate, and the second irregularly shaped orifice plate 220 can accelerate evaporation and promote the thorough mixing of the broken droplets and the exhaust gas.

[0040] In an exemplary embodiment, the first flow guide is a tapered flow guide plate 140, on which a plurality of flow guide holes 141 are formed. Figure 3 As shown, the larger diameter end of the conical guide plate 140 is close to the first mixing component 200, and the smaller diameter end is close to the outlet of the front mixer 100. The inclined structure of the conical guide plate 140 can guide and converge the flow direction of the mixed fluid passing through the first guide component, so that the originally unidirectional rotating fluid flows towards the central axis, reducing the flow resistance, accelerating the mixing of exhaust gas and the first urea spray, allowing the urea to fully evaporate and contact with the nitrogen oxides in the exhaust gas, improving the efficiency of the catalytic reduction reaction, and preventing the rotating airflow from flowing more towards the edge area of ​​the catalyst, causing the airflow eccentricity to be too large, which would lead to catalyst cracking.

[0041] In one exemplary embodiment, the diameter of the flow guide hole 141 is less than or equal to 6 mm. When the diameter of the flow guide hole 141 is within this range, the flow guiding and mixing effect can be improved.

[0042] In one exemplary embodiment, the axial angles between the first irregularly shaped orifice plate 210, the second irregularly shaped orifice plate 220 and the first urea spray inlet 110 are different from the axial angles between the third irregularly shaped orifice plate 410, the fourth irregularly shaped orifice plate 420 and the second urea spray inlet 310.

[0043] In an exemplary embodiment, the first shaped perforated plate 210, the second shaped perforated plate 220, the third shaped perforated plate 410, and the fourth shaped perforated plate 420 are each provided with a plurality of shaped holes 510. A guide plate 520 is inclinedly disposed on one side of each shaped hole 510, and the plurality of guide plates 520 located on the same shaped perforated plate have the same inclination direction. The guide plate 520 can change the flow direction of the fluid passing through the shaped holes 510, causing laminar flow to change into turbulent flow, thereby facilitating the full mixing of exhaust gas and urea droplets. The arrayed shaped holes 510 and guide plates 520 can also play a forced diversion role, reducing the crystallization of local urea droplets.

[0044] In an exemplary embodiment, the front-end mixer 100 further includes a first arc-shaped guide plate 150, the first end of which is connected to the inner wall of the front-end mixer 100; the rear-end mixer 300 further includes a second arc-shaped guide plate 340, one end of which is connected to the inner wall of the front-end mixer 100. The first end of the first arc-shaped guide plate 150 can be located on one side of the first urea spray inlet 110, and the other end extends along the extension direction of the orifice plate. The arc-shaped guide plate 520 can initially change the flow direction of the urea spray entering the mixer, causing the spray droplets to move from the area near the wall towards the center of the flow channel, and can also promote heat exchange between the exhaust gas and the spray, improving mixing efficiency.

[0045] In an exemplary embodiment, the inner diameter of the front-end mixer 100 is smaller than that of the rear-end mixer 300. The smaller inner diameter of the front-end mixer 100 results in a higher flow velocity after the exhaust gas and urea are initially mixed. As the gas enters the larger-diameter rear-end mixer 300, the flow velocity decreases, creating a turbulent environment. This provides more space for urea diffusion, extending the residence time of urea droplets in the high-temperature exhaust gas, promoting evaporation into ammonia, reducing crystallization caused by unevaporated urea particles entering the rear-end mixer 300, and improving the uniformity of secondary mixing. The increased inner diameter of the rear-end mixer 300 increases the airflow cross-sectional area and raises static pressure, compensating for the pressure loss at the front end and preventing excessive back pressure from affecting engine exhaust efficiency. During high-load engine operation, the large inner diameters of the connecting section 600 and the rear-end mixer 300 prevent insufficient mixing time due to excessive flow velocity; during low-load operation, the gradually expanding structure still ensures mixing efficiency through turbulence, preventing urea sedimentation due to low flow velocity.

[0046] In an exemplary embodiment, a connecting section 600 is provided between the front-end mixer 100 and the back-end mixer 300, and the inner diameter of the connecting section 600 is smaller than the inner diameter of the back-end mixer 300. The inner diameter of the connecting section 600 can be greater than or equal to the inner diameter of the front-end mixer 100. By providing the connecting section 600 with an inner diameter smaller than that of the back-end mixer 300, the front-end mixer 100, the connecting section 600, and the back-end mixer 300 can form a gradually expanding structure. The gas flowing out of the front-end mixer 100 and the urea spray can be further mixed in the connecting section 600, improving the uniformity of the gas entering the back-end mixer 300.

[0047] In one exemplary embodiment, a urea dual-spray aftertreatment device is proposed, namely, an aftertreatment device containing both front and rear mixers. This device can effectively break up urea spray particles. The broken urea spray at the front end passes through a mixing perforated plate with the airflow, which can evenly distribute urea on the front end face of the SCR, making the ammonia and the exhaust gas mix more thoroughly. At the same time, the mixing perforated plate can improve the airflow uniformity and improve the conversion efficiency of MFC for CO, HC and NOx. In addition, the mixer also has the advantages of low back pressure and relatively simple structure.

[0048] The front-end mixer includes:

[0049] A cylindrical body extends axially and is provided with a mounting base. The cylindrical body includes an air inlet end and an air outlet end.

[0050] The device contains two irregularly shaped perforated baffles, which are installed in parallel on the cylinder.

[0051] A crushing plate is provided in the cylinder, and the crushing plate has a plurality of crushing holes and is installed between two irregularly shaped hole partitions.

[0052] A conical orifice plate, located in the cylinder, has several 6mm holes and serves as a flow guide. This allows the gas to flow out from the orifice plate and into the downstream device. It can concentrate the unidirectional rotating airflow and urea in the cylinder towards the center, preventing the rotating airflow from flowing too far to the edge of the catalyst, which would cause excessive airflow eccentricity and lead to catalyst cracking.

[0053] The backend mixer includes:

[0054] A cylindrical body extends axially and is provided with a mounting base. The cylindrical body includes an air inlet end and an air outlet end.

[0055] The device contains two irregularly shaped perforated baffles, which are installed in parallel on the cylinder.

[0056] A crushing plate is provided in the cylinder, and the crushing plate has a plurality of crushing holes and is installed between two irregularly shaped hole partitions.

[0057] The airflow uniformity is already relatively high after passing through the DDPF, so no tapered orifice plate is installed in the rear mixer.

[0058] In one exemplary embodiment, a vehicle is also provided, including a urea dual-injection exhaust gas treatment device as described in any of the above embodiments. The vehicle may be a gasoline vehicle, a diesel vehicle, or a hybrid vehicle.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A urea dual injection tail gas treatment apparatus, characterized by, The application relates to a urea double-spray aftertreatment device. The front-end mixer comprises a first urea spray inlet, a first gas inlet end, a first mixing element and a first gas outlet end, wherein the first gas inlet end is used for connecting an engine exhaust port, the first urea spray inlet is arranged on the side wall of the front-end mixer, the first mixing element is arranged opposite to the first urea spray inlet, and the first gas outlet end is provided with a first flow guide element. The rear-end mixer comprises a second urea spray inlet, a second gas inlet end, a second mixing element and a second gas outlet end, wherein the second gas inlet end is connected with the first gas outlet end, the second urea spray inlet is arranged on the side wall of the rear-end mixer, the second mixing element is arranged opposite to the second urea spray inlet, and the second gas outlet end is connected with the atmosphere.

2. The urea dual injection tail gas treatment apparatus according to claim 1, characterized by, The first mixing element comprises a first special-shaped hole plate, a first broken hole plate and a second special-shaped hole plate which are arranged in parallel, the first special-shaped hole plate, the broken hole plate and the second special-shaped hole plate at least partially coincide with the projection of the first urea spray inlet in the axial direction of the first urea spray inlet, and the first special-shaped hole plate, the broken hole plate and the second special-shaped hole plate are arranged obliquely relative to the axial direction of the first urea spray inlet. The second mixing element comprises a third special-shaped hole plate, a second broken hole plate and a fourth special-shaped hole plate which are arranged in parallel, the third special-shaped hole plate, the second broken hole plate and the fourth special-shaped hole plate at least partially coincide with the projection of the second urea spray inlet in the axial direction of the second urea spray inlet, and the third special-shaped hole plate, the second broken hole plate and the fourth special-shaped hole plate are arranged obliquely relative to the axial direction of the second urea spray inlet.

3. The urea dual injection tail gas treatment apparatus according to claim 1, wherein, The first flow guide element is a conical flow guide plate, and a plurality of flow guide holes are arranged on the conical flow guide plate.

4. The urea dual injection tail gas treatment apparatus according to claim 3, characterized in that, The diameter of the flow guide hole is less than or equal to 6 mm.

5. The urea dual injection tail gas treatment apparatus according to claim 2, wherein, The included angles of the first special-shaped hole plate, the second special-shaped hole plate and the axial direction of the first urea spray inlet and the included angles of the third special-shaped hole plate, the fourth special-shaped hole plate and the axial direction of the second urea spray inlet are different.

6. The urea dual injection tail gas treatment apparatus according to claim 2, wherein A plurality of special-shaped holes are arranged on the first special-shaped hole plate, the second special-shaped hole plate, the third special-shaped hole plate and the fourth special-shaped hole plate, and a flow guide plate is arranged on one side of each special-shaped hole, and the flow guide plates arranged on the same special-shaped hole plate are arranged in the same oblique direction.

7. The urea dual injection tail gas treatment apparatus according to claim 1, wherein The front-end mixer further comprises a first arc-shaped flow guide plate, and one end of the second arc-shaped flow guide plate is connected with the inner wall of the front-end mixer.

8. The urea dual injection tail gas treatment apparatus according to claim 1, wherein, The inner diameter of the front-end mixer is smaller than the inner diameter of the rear-end mixer.

9. The urea dual injection tail gas treatment apparatus according to claim 1, wherein, A connecting section is arranged between the front-end mixer and the rear-end mixer, and the inner diameter of the connecting section is smaller than the inner diameter of the rear-end mixer.

10. A vehicle characterized by comprising: The application further relates to a urea double-spray aftertreatment device.

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