Tail gas after-treatment device and diesel engine

Abstract

The utility model provides a tail gas after-treatment device and diesel engine, the tail gas after-treatment device comprises a shell, air inlet end cone and air outlet pipe, the air inlet end cone is connected with one end of the shell, the air outlet pipe is connected with the other end of the shell, the shell is internally provided with a DOC assembly, a DPF assembly, a supporting pipe and an SCR assembly, a mixer is arranged in the supporting pipe, and the supporting pipe is detachably connected with the mixer. The mixer is installed through the supporting pipe, the supporting pipe is detachably connected with the mixer, and the mixer can be independently replaced by detaching the mixer from the supporting pipe.

Description

Technical Field

[0001] This utility model relates to the field of catalytic conversion technology for diesel engine exhaust emissions, and in particular to an exhaust aftertreatment device and a diesel engine. Background Technology

[0002] With increasing environmental awareness, stricter standards have been set for diesel engine emissions. Current regulations prohibit direct emission of diesel exhaust; it must undergo purification treatment before being released. Existing China VI aftertreatment systems primarily employ box-type, U-type, and cylindrical structures, all using the DOC+DPF+SCR+ASC technology route. To ensure thorough mixing of the urea solution with the airflow, a mixer is placed between the DPF and SCR in the aftertreatment system. However, due to the influence of engine exhaust flow, exhaust temperature, and urea injection volume, crystallization easily occurs in the mixer. Small amounts of crystallization can be resolved by increasing exhaust temperature through active regeneration, but when the amount of crystallization is large or even completely blocks the mixer, it must be disassembled and cleaned. However, the mixer in existing box-type China VI aftertreatment systems cannot be disassembled; the crystallization problem can only be solved by replacing the entire aftertreatment assembly, resulting in high after-sales maintenance costs. Utility Model Content

[0003] This invention provides an exhaust gas aftertreatment device to solve the problem of mixer crystallization that requires replacing the entire aftertreatment assembly in the prior art.

[0004] This utility model provides an exhaust gas aftertreatment device, including a housing, an inlet cone, and an outlet pipe. The inlet cone is connected to one end of the housing, and the outlet pipe is connected to the other end of the housing. The housing contains a DOC assembly, a DPF assembly, a support pipe, and an SCR assembly. The support pipe contains a mixer, and the support pipe is detachably connected to the mixer.

[0005] According to the present invention, an exhaust gas aftertreatment device is provided, the exhaust gas aftertreatment device further includes a first support plate and a second support plate, the first support plate being connected to one end of the housing, and the second support plate being connected to the other end of the housing.

[0006] According to the present invention, an exhaust gas aftertreatment device is provided, the exhaust gas aftertreatment device further includes a first flow guide cavity, and the SCR assembly is connected to the exhaust pipe through the first flow guide cavity.

[0007] According to the present invention, an exhaust gas aftertreatment device is provided, the exhaust gas aftertreatment device further includes a second flow guide cavity, and the mixer is connected to the SCR assembly through the second flow guide cavity.

[0008] According to the present invention, an exhaust gas aftertreatment device further includes a urea nozzle connected to one end of the mixer near the exhaust pipe.

[0009] According to the exhaust gas aftertreatment device provided by this utility model, the urea nozzle is inserted into the mixer at one end near the outlet pipe, and the length of the portion of the urea nozzle located inside the mixer is greater than or equal to 30 mm.

[0010] According to the present invention, an exhaust gas aftertreatment device is provided, the mixer includes a swirl tube, a mixing tube, and a mounting base. The mixing tube is connected to one end near the exhaust pipe, the swirl tube is connected to the other end of the mixing tube, and the mounting base is connected to the mixing tube.

[0011] According to the exhaust gas aftertreatment device provided by this utility model, the mixer further includes a sealing gasket and a baffle. The baffle is connected to one end of the mixing pipe near the exhaust pipe, and the sealing gasket is connected to the end of the baffle away from the mixing pipe.

[0012] According to the exhaust gas aftertreatment device provided by this utility model, the mixing pipe is provided with an air hole at one end connected to the DPF assembly, and the opening degree of the mixing pipe is greater than 80%.

[0013] This utility model also provides a diesel engine, including the exhaust aftertreatment device described above.

[0014] This utility model provides an exhaust gas aftertreatment device and a diesel engine. The exhaust gas aftertreatment device uses a housing to mount a support pipe, and a mixer is installed inside the support pipe. The mixer is detachably connected to the support pipe, so the mixer can be removed from the housing. When large or numerous crystals cause blockage in the mixer, the mixer can be removed from the housing. Removing the mixer from the housing facilitates the cleaning of crystals and also facilitates the replacement of the mixer. The exhaust gas aftertreatment device provided by this utility model allows for the individual replacement of the mixer by removing it from the housing, thus saving resources. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the exhaust gas aftertreatment device provided by this utility model.

[0017] Figure 2 This is a front view of the exhaust gas aftertreatment device provided by this utility model.

[0018] Figure 3 yes Figure 2 Cross-sectional view at point AA.

[0019] Figure 4 yes Figure 3 Cross-sectional view at point BB.

[0020] Figure 5 This is a front view of the mixer provided by this utility model.

[0021] Figure 6 yes Figure 5 Cross-sectional view at point C.

[0022] Figure label:

[0023] 1. Inlet cone; 2. First support plate; 3. DOC assembly; 4. DPF assembly; 5. Housing; 6. Second support plate; 7. Third guide cavity; 8. First guide cavity; 9. Fixing bolt; 10. Mixer; 101. Swirl tube; 102. Mixing tube; 103. Sealing gasket; 104. Baffle; 105. Nozzle mounting seat; 11. Urea nozzle; 12. Outlet pipe; 13. SCR assembly; 14. Support tube; 15. Second guide cavity. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] The following is combined with Figure 1 This utility model describes an exhaust gas aftertreatment device, including a housing 5, an inlet cone 1, and an outlet pipe 12. The inlet cone 1 is connected to one end of the housing 5, and the outlet pipe 12 is connected to the other end of the housing 5. The housing 5 is provided with a DOC assembly 3, a DPF assembly 4, a support pipe 14, and an SCR assembly 13. The support pipe 14 is provided with a mixer 10, and the support pipe 14 and the mixer 10 are detachably connected.

[0026] Please refer to the above as well. Figures 1 to 6Since this embodiment targets a box-type after-processor, the housing 5 is approximately rectangular. The housing 5 includes an internal mounting space that is approximately cuboid in shape. The DOC assembly 3, DPF assembly 4, support pipe 14, and SCR assembly 13 are all installed within this internal mounting space. At the front and rear ends of the housing 5, respectively, are connected an intake cone 1 and an exhaust pipe 12. Exhaust gas first enters the DOC assembly 3, which is connected to the intake cone 1, through the intake cone 1. Then, it passes sequentially through the DPF assembly 4, mixer 10, and SCR assembly 13. After purification by these devices, it is discharged through the exhaust pipe 12.

[0027] The support tube 14 is a hollow tube used to install the mixer 10. The mixer 10 is located inside the support tube 14, and the support tube 14 is detachably connected to the mixer 10. During the operation of the mixer 10, urea crystals are easily generated inside the mixer 10. When there are many urea crystals inside the mixer 10 or when the volume of a single urea crystal is large, it is easy to cause blockage of the mixer 10. After the mixer 10 is blocked, its operation is restricted, and it is necessary to clean the urea crystals from the mixer 10. Because the mixer 10 is located inside the housing 5, it is not convenient to clean the urea crystals from the mixer 10. It is necessary to remove the mixer 10 to provide sufficient space for operation.

[0028] In existing technology, the mixer 10 is connected to the after-processor assembly by welding, making it impossible to remove. When excessive urea crystals cause blockage in the mixer 10, the entire after-processor assembly needs to be disassembled for cleaning. Furthermore, because the mixer 10 is inside the after-processor assembly, it's inconvenient to operate, so the mixer 10 is simply replaced. However, since the mixer 10 is welded to the after-processor assembly, it cannot be replaced individually. The need to replace the entire after-processor assembly when urea crystals cause blockage in the mixer 10 significantly increases maintenance and replacement costs, resulting in a waste of resources.

[0029] In this embodiment, the mixer 10 is installed inside the support tube 14, which in turn is installed inside the housing 5. The support tube 14 is detachably connected to the mixer 10, allowing the mixer 10 to be removed separately.

[0030] Therefore, when there is a large amount of urea crystals inside the mixer 10, causing blockage, the mixer 10 can be removed separately from the housing 5. Then, the mixer 10 can be placed in an open area with sufficient operating space to clean the urea crystals inside. Preferably, in this embodiment, the outer diameter of the mixer 10 is designed to be 10mm smaller than the outer diameter of the support tube 14. This provides a larger clearance when the mixer 10 is installed inside the support tube 14 or removed from the support tube 14, facilitating the installation and removal of the mixer 10 within the support tube 14.

[0031] In this embodiment, by detachably installing the mixer 10 in the support tube 14 inside the housing 5, when urea crystal blockage occurs in the mixer 10, the mixer 10 can be removed separately for cleaning, without having to disassemble and replace the entire exhaust gas aftertreatment device, thus reducing maintenance costs.

[0032] In one embodiment, the exhaust gas aftertreatment device further includes a first support plate 2 and a second support plate 6, wherein the first support plate 2 is connected to one end of the housing 5 and the second support plate 6 is connected to the other end of the housing 5.

[0033] like Figure 1 As shown, a first support plate 2 and a second support plate 6 are respectively provided at the front and rear ends of the housing 5. The first support plate 2 closes the front end of the housing 5, and the second support plate 6 closes the rear end of the housing 5. The intake cone 1 is connected to the housing 5 through the first support plate 2, and the exhaust pipe 12 is connected to the housing 5 through the second support plate 6, so that the exhaust gas can only enter the housing 5 from the intake cone 1 and exit from the exhaust pipe 12, ensuring the airtightness of the housing 5.

[0034] In one embodiment, the exhaust aftertreatment device further includes a first guide cavity 8, through which the SCR assembly 13 is connected to the exhaust pipe 12. In another embodiment, the exhaust aftertreatment device further includes a second guide cavity 15, through which the mixer 10 is connected to the SCR assembly 13.

[0035] like Figure 1As shown, in this embodiment, the housing 5 is approximately cuboid, corresponding to a box-type exhaust aftertreatment device. Therefore, in this embodiment, the DOC assembly 3, DPF assembly 4, mixer 10, and SCR assembly 13 are arranged side-by-side within the housing 5. The DOC assembly 3, DPF assembly 4, mixer 10, and SCR assembly 13 cannot be axially aligned and connected to each other. Therefore, in this embodiment, a first guide cavity 8, a second guide cavity 15, and a third guide cavity 7 are provided. The third guide cavity 7 connects the DPF assembly 4 to the mixer 10, the second guide cavity 15 connects the mixer 10 to the SCR assembly 13, and the first guide cavity 8 connects the SCR assembly 13 to the exhaust pipe 12. In this embodiment, the DOC assembly 3 and DPF assembly 4 are relatively short, so they can be aligned and connected along the axial direction. The other end of the DOC assembly 3 is connected to the intake cone 1.

[0036] Exhaust gas enters the DOC assembly 3 through the intake cone 1, then the DPF assembly 4, then the mixer 10 through the third guide cavity 7, then the SCR assembly 13 through the second guide cavity 15, and finally flows into the exhaust pipe 12 through the first guide cavity 8 and is discharged through the exhaust pipe 12. In this embodiment, the arrangement of the first guide cavity 8, the second guide cavity 15, and the third guide cavity 7 ensures that the exhaust gas can flow within the box-type exhaust gas aftertreatment device, ensuring the correct flow direction of the exhaust gas.

[0037] In one embodiment, the exhaust aftertreatment device further includes a urea nozzle 11, which is connected to the end of the mixer 10 near the outlet pipe 12. In one embodiment, the urea nozzle 11 passes through the end of the mixer 10 near the outlet pipe 12, and the length of the portion of the urea nozzle 11 inside the mixer 10 is greater than or equal to 30 mm.

[0038] Please refer to the above as well. Figure 1 and Figure 3 A urea nozzle 11 is connected to the right side of the mixer 10. The urea nozzle 11 can spray a urea aqueous solution into the mixer 10, thereby purifying the exhaust gas. In this embodiment, the exhaust gas enters the mixer 10 from the end near the outlet pipe 12. Therefore, by connecting the urea nozzle 11 to the end of the mixer 10 near the outlet pipe 12, the exhaust gas mixes with the urea aqueous solution sprayed from the urea nozzle 11 as soon as it enters the mixer 10, thereby prolonging the mixing time between the exhaust gas and the urea aqueous solution and improving the purification effect.

[0039] Since the function of the urea nozzle 11 is to spray urea aqueous solution into the mixer 10, the nozzle only needs to have its spray port located inside the mixer 10. Because the length of the housing 5 corresponds to the length of the mixer 10, the portion located outside the mixer 10 would increase the length of the housing 5, thus increasing the overall length of the exhaust gas aftertreatment device. Therefore, in this embodiment, the urea nozzle 11 is partially located inside the mixer 10, thereby shortening the length of the urea nozzle 11 protruding outside the housing 5. Preferably, in this embodiment, the portion of the urea nozzle 11 located inside the mixer 10 is set to 30mm, ensuring that while shortening the length of the exhaust gas aftertreatment device, there is still sufficient space for the exhaust gas to mix with the urea aqueous solution.

[0040] In one embodiment, the mixer 10 includes a swirl tube 101, a mixing tube 102, and a mounting base 105. The mixing tube 102 is connected to one end near the outlet pipe 12, the swirl tube 101 is connected to the other end of the mixing tube 102, and the mounting base 105 is connected to the mixing tube 102. In another embodiment, the mixer 10 further includes a sealing gasket 103 and a baffle 104. The baffle 104 is connected to the end of the mixing tube 102 near the outlet pipe 12, and the sealing gasket 103 is connected to the end of the baffle 104 away from the mixing tube 102.

[0041] like Figure 6 As shown, the right side of the mixer 10 is the mixing pipe 102. The exhaust gas from the DPF assembly 4 first enters the mixing pipe 102. Therefore, the urea nozzle 11 is also connected to one end of the mixing pipe 102, so that the exhaust gas mixes with the urea aqueous solution after entering the mixing pipe 102. Then it passes through the swirl tube 101 and flows from the swirl tube 101 to the second guide chamber 15.

[0042] A sealing gasket 103 and a baffle 104 are provided at the end of the mixing pipe 102 facing the urea nozzle 11. Since the urea nozzle 11 passes through the mixing pipe 102, the sealing gasket 103 and the baffle 104 ensure the sealing of the connection between the urea nozzle 11 and the mixing pipe 102. At the same time, a nozzle mounting seat 15 is provided inside the mixing pipe 102 for mounting the urea nozzle 11.

[0043] Preferably, the left end of the mixing tube 102 is press-fitted to the end reinforcing rib of the support tube 14, preventing airflow from entering the second guide cavity 15 from this point. Furthermore, the swirl tube 101 is provided with swirl blades, which allow airflow to enter the swirl tube 101 in a rotating manner, facilitating the mixing of the airflow with the urea aqueous solution.

[0044] In one embodiment, the end of the mixing tube 102 connected to the DPF assembly 4 is provided with an air hole, and the opening degree of the mixing tube 102 is greater than 80%.

[0045] Because the exhaust gas from the DPF assembly 4 first enters the mixing pipe 102, vents are made in the mixing pipe 102, and the opening degree of the mixing pipe 102 is greater than 80%, thereby ensuring the flow of exhaust gas from the DPF assembly 4 into the mixing pipe 102.

[0046] This utility model also provides a diesel engine, including the exhaust aftertreatment device described above. Using the exhaust aftertreatment device described above, the mixer 10 can be removed separately when it is clogged by urea crystals, reducing maintenance costs.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A tail gas aftertreatment device, characterized in that, The device includes a housing (5), an intake cone (1), and an exhaust pipe (12). The intake cone (1) is connected to one end of the housing (5), and the exhaust pipe (12) is connected to the other end of the housing (5). The housing (5) contains a DOC assembly (3), a DPF assembly (4), a support pipe (14), and an SCR assembly (13). The support pipe (14) contains a mixer (10), and the support pipe (14) is detachably connected to the mixer (10). The outer diameter of the mixer (10) is 10 mm smaller than the outer diameter of the support pipe (14).

2. The exhaust gas aftertreatment device according to claim 1, characterized in that, The exhaust gas aftertreatment device also includes a first support plate (2) and a second support plate (6), the first support plate (2) being connected to one end of the housing (5) and the second support plate (6) being connected to the other end of the housing (5).

3. The exhaust gas aftertreatment device according to claim 2, characterized in that, The exhaust gas aftertreatment device also includes a first guide cavity (8), and the SCR assembly (13) is connected to the exhaust pipe (12) through the first guide cavity (8).

4. The exhaust gas aftertreatment device according to claim 2, characterized in that, The exhaust gas aftertreatment device also includes a second guide cavity (15), through which the mixer (10) is connected to the SCR assembly (13).

5. The exhaust gas aftertreatment device according to claim 1, characterized in that, The exhaust gas aftertreatment device also includes a urea nozzle (11), which is connected to one end of the mixer (10) near the exhaust pipe (12).

6. The exhaust gas aftertreatment device according to claim 5, characterized in that, The urea nozzle (11) is inserted into the mixer (10) at one end near the outlet pipe (12), and the length of the portion of the urea nozzle (11) inside the mixer (10) is greater than or equal to 30 mm.

7. The exhaust gas aftertreatment device according to claim 1, characterized in that, The mixer (10) includes a swirl tube (101), a mixing tube (102), and a mounting base (105). The mixing tube (102) is connected to one end near the outlet tube (12), the swirl tube (101) is connected to the other end of the mixing tube (102), and the mounting base (105) is connected to the mixing tube (102).

8. The exhaust gas aftertreatment device according to claim 7, characterized in that, The mixer (10) also includes a sealing gasket (103) and a baffle (104), the baffle (104) being connected to one end of the mixing tube (102) near the outlet tube (12), and the sealing gasket (103) being connected to one end of the baffle (104) away from the mixing tube (102).

9. The exhaust gas aftertreatment device according to claim 7, characterized in that, The mixing tube (102) is provided with an air hole at one end that is connected to the DPF assembly (4), and the opening degree of the mixing tube (102) is greater than 80%.

10. A diesel engine, characterized in that, Includes the exhaust gas aftertreatment device as described in any one of claims 1 to 9.

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