Exhaust aftertreatment device

Abstract

An exhaust aftertreatment device comprises a first aftertreatment assembly and a second aftertreatment assembly, the first aftertreatment assembly comprises a first mixing cavity assembly, and the second aftertreatment assembly comprises a second mixing cavity assembly. The first mixing cavity assembly and the second mixing cavity assembly are detachably connected together, and maintenance is convenient. The first mixing cavity assembly comprises a first mixing pipe located in the first mixing cavity assembly and a perforated pipe at least partially located in the first mixing pipe. The second mixing cavity assembly comprises a second mixing pipe located in the second mixing cavity assembly and a blocking piece located in the second mixing pipe. The perforated pipe further extends into the second mixing pipe and is located on the upstream of the blocking piece. Through the arrangement, the urea evaporation distance and time are increased, the airflow mixing uniformity is improved, and the crystallization resistance is improved.

Description

[0001] This application is a divisional application of the patent application with the application date of January 26, 2018, application number 201810078200.7, and invention creation name of "Exhaust Aftertreatment Device". Technical Field

[0002] The present invention relates to an exhaust aftertreatment device, belonging to the technical field of engine exhaust aftertreatment. Background Art

[0003] Research shows that the uniformity of ammonia distribution in the pipeline of an exhaust aftertreatment system (such as a selective catalytic reduction system, SCR system) has an important impact on the overall performance and durability of the system. If the ammonia (NH 3 ) distribution is uneven, it will lead to too low conversion efficiency of nitrogen oxides (NOx). If the urea injection amount is increased to meet the emission performance, ammonia leakage pollution is likely to occur. At the same time, urea droplets are likely to deposit when contacting a wall surface with a lower temperature, forming crystals, which will seriously block the exhaust pipe and cause a decline in the engine's power performance when severe. Improving the mixing uniformity of ammonia molecules can effectively improve the urea utilization rate, reduce the urea injection amount, and thus reduce the risk of urea crystallization.

[0004] Therefore, it is necessary to provide an exhaust aftertreatment device that can improve the mixing uniformity of ammonia molecules to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide an exhaust aftertreatment device that is easy to maintain and can make the exhaust of the engine mix uniformly with urea droplets.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An exhaust aftertreatment device includes a first aftertreatment component and a second aftertreatment component arranged side by side with the first aftertreatment component. The first aftertreatment component includes a first carrier component, an exhaust inlet pipe located on one side of the first carrier component, and a first mixing cavity component located on the other side of the first carrier component; the second aftertreatment component includes a second carrier component, an exhaust outlet pipe located on one side of the second carrier component, and a second mixing cavity component located on the other side of the second carrier component. The first mixing cavity component and the second mixing cavity component are located on the same side of the exhaust aftertreatment device, and the exhaust aftertreatment device is U-shaped; the first mixing cavity component includes a first mixing pipe therein and a porous pipe at least partially located in the first mixing pipe. The first mixing pipe further includes a plurality of swirl fins distributed circumferentially and slots corresponding to the swirl fins; the second mixing cavity component includes a second mixing pipe therein and a baffle located in the second mixing pipe. The baffle is provided with a plurality of first openings for urea fragmentation, and the second mixing pipe is provided with a plurality of second openings distributed on its peripheral wall; the porous pipe further extends into the second mixing pipe and is located upstream of the baffle; the first mixing pipe and the second mixing pipe are detachably connected by a clamp to detachably connect the first mixing cavity component and the second mixing cavity component together.

[0007] As a further improved technical solution of the present invention, the first mixing cavity component is provided with a top wall, and the top wall is provided with a spray hole for a urea nozzle to spray urea droplets into the porous pipe.

[0008] As a further improved technical solution of the present invention, the first mixing pipe includes a conical portion, and the swirl fins and the slots are both provided on the conical portion; one end of the porous pipe is close to the spray hole.

[0009] As a further improved technical solution of the present invention, the second mixing pipe is provided with an arc-shaped end bowl at the bottom for forcing the air flow to reverse.

[0010] As a further improved technical solution of the present invention, the second mixing cavity component includes an arc-shaped end cover located on the side for guiding the air flow coming out of the second mixing pipe to the second carrier component.

[0011] As a further improved technical solution of the present invention, the first mixing pipe extends beyond the first mixing cavity component, and the second mixing pipe extends beyond the second mixing cavity component.

[0012] As a further improved technical solution of the present invention, the first carrier assembly includes a diesel oxidation catalyst and a diesel particulate filter located downstream of the diesel oxidation catalyst, and the second carrier assembly includes a selective catalytic reducer.

[0013] As a further improved technical solution of the present invention, the first mixing cavity assembly includes a first annular cavity located between the first mixing pipe and the porous pipe, the second mixing cavity assembly includes a second annular cavity located between the second mixing pipe and the porous pipe, and the first annular cavity communicates with the second annular cavity.

[0014] Compared with the prior art, by providing the detachable first mixing cavity assembly and the second mixing cavity assembly, the present invention is convenient for maintenance; in addition, by providing the first mixing pipe, the second mixing pipe and the porous pipe, the evaporation distance and time of urea are increased, the uniformity of gas flow mixing is improved, and the anti-crystallization ability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an end view schematic diagram of the exhaust aftertreatment device of the present invention.

[0016] Figure 2 is Figure 1 a cross-sectional schematic diagram taken along line A-A in

[0017] Figure 3 is a partial three-dimensional exploded view of the exhaust aftertreatment device of the present invention.

[0018] Figure 4 is Figure 3 a further three-dimensional exploded view, in which the exhaust inlet pipe is separated.

[0019] Figure 5 is a partial three-dimensional exploded view of the exhaust aftertreatment device of the present invention, in which the DPF carrier assembly is separated.

[0020] Figure 6 is Figure 5 a further three-dimensional exploded view.

[0021] Figure 7 is Figure 6 a further three-dimensional exploded view.

[0022] Figure 8 is Figure 1 a three-dimensional schematic diagram of the exhaust inlet pipe in

[0023] Figure 9 is Figure 8 the front view of

[0024] Figure 10 is Figure 8 the top view of

[0025] Figure 11 is Figure 8 a three-dimensional exploded view of

[0026] Figure 12 is Figure 11 a three-dimensional exploded view from another angle.

[0027] Figure 13 is a three-dimensional schematic view of the exhaust inlet pipe in another embodiment.

[0028] Figure 14 is Figure 13 a top view of

[0029] Figure 15 is Figure 13 a front view of Detailed Embodiment

[0030] Please refer to Figures 1 to 7 As shown, the present invention discloses an exhaust aftertreatment device 300, which includes a first aftertreatment component 100 and a second aftertreatment component 200 arranged side by side with the first aftertreatment component 100. The first aftertreatment component 100 includes a first carrier component 11, an exhaust inlet pipe 12 located on one side of the first carrier component 11, and a first mixing cavity component 13 located on the other side of the first carrier component 11. The second aftertreatment component 200 includes a second carrier component 21, an exhaust outlet pipe 22 located on one side of the second carrier component 21, and a second mixing cavity component 23 located on the other side of the second carrier component 21.

[0031] In the illustrated embodiment of the present invention, the exhaust aftertreatment device 300 is U-shaped. The first mixing cavity component 13 and the second mixing cavity component 23 are located on the same side of the exhaust aftertreatment device 300.

[0032] In the illustrated embodiment of the present invention, the first carrier component 11 includes a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF) located downstream of the diesel oxidation catalyst, and the second carrier component 21 includes a selective catalytic reducer (SCR).

[0033] The first mixing cavity component 13 and the second mixing cavity component 23 are detachably connected together for easy maintenance.

[0034] The first mixing cavity component 13 includes a first mixing pipe 131 located therein and a porous pipe 132 at least partially located in the first mixing pipe 131. The first mixing pipe 131 includes a conical portion 133, which includes a plurality of swirl fins 134 distributed circumferentially and slots 135 corresponding to the swirl fins 134.

[0035] The first mixing cavity assembly 13 is provided with a top wall 136, and the top wall 136 is provided with injection holes 137 for a urea nozzle (not shown) to inject urea droplets into the porous tube 132. One end of the porous tube 132 is close to the injection holes 137.

[0036] The second mixing cavity assembly 23 includes a second mixing tube 231 located therein and a baffle 232 located in the second mixing tube 231. The baffle 232 is provided with a plurality of first openings 233 for urea fragmentation. The second mixing tube 231 is provided with a plurality of second openings 234 distributed on its peripheral wall. The porous tube 132 further extends into the second mixing tube 231 and is located upstream of the baffle 232. The second mixing tube 231 is provided with an arc-shaped end bowl 234 at the bottom for forcing the air flow to reverse. The second mixing cavity assembly 23 includes an arc-shaped end cover 235 located on the side for guiding the air flow coming out of the second mixing tube 231 towards the second carrier assembly 21. Additionally, the baffle 232 can prevent excessive urea from directly spraying on the end cover 235 and forming crystallization.

[0037] In the illustrated embodiment of the present invention, the first mixing tube 131 extends beyond the first mixing cavity assembly 13, the second mixing tube 231 extends beyond the second mixing cavity assembly 23, and the first mixing tube 131 and the second mixing tube 231 are detachably connected by a clamp 236.

[0038] Please refer Figures 8 to 12 As shown, the exhaust inlet pipe 12 of the present invention is of a flat design to reduce the length of the entire exhaust aftertreatment device 300, and thus can better adapt to the strict installation space.

[0039] In a first embodiment of the exhaust inlet pipe 12 of the present invention, the exhaust inlet pipe 12 includes a first housing portion 121, a second housing portion 122 that mates with the first housing portion 121, and an intake flange 123 that connects the first housing portion 121 and the second housing portion 122.

[0040] The first housing portion 121 includes a terminal portion 1211 and an arc portion 1212 extending from the terminal portion 1211. The terminal portion 1211 forms a part of the intake pipe. In the illustrated embodiment of the present invention, the terminal portion 1211 is arc-shaped. The terminal portion 1211 is provided with a first edge 1213. The arc portion 1212 is provided with a sensor seat 1214 for installing a sensor. The arc portion 1212 is provided with an outlet end face 1215, and the outlet end face 1215 is located inside the first edge 1213, that is, from Figure 9Viewed from the position shown, the outlet end face 1215 is lower than the first edge 1213.

[0041] The second housing portion 122 is provided with a second edge 1221 that engages with the first edge 1213. The seam between the first edge 1213 and the second edge 1221 is generally L-shaped. Please refer Figure 9 As shown, in the illustrated embodiment of the present invention, the first edge 1213 and the second edge 1221 are welded together to form an intake duct. The intake duct is provided with an inlet cross-section M, and at least a part of the first carrier assembly 11 protrudes into the area of the inlet cross-section M. At the same time, the outlet end face 1215 also at least partially protrudes into the area of the inlet cross-section M. With such a setting, the length of the exhaust aftertreatment device 300 can be reduced. In the illustrated embodiment of the present invention, the intake flange 123 at least partially sleeves outside the intake duct and is fixed to the intake duct. The intake flange 123 includes a flange plate 1231 located outside the intake duct.

[0042] Figures 13 to 15 A second embodiment of the exhaust inlet pipe 12 of the present invention is disclosed, which is different from the first embodiment in that the intake flange 123 is not provided.

[0043] It should be noted that the orientations such as "upper", "lower", "top", "bottom", "below" described in the present invention should not be understood in a limited sense, because these positional relationships should also be understood adaptively according to the different placement positions of the components. In addition, the above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention. The understanding of this specification should be based on those skilled in the art of the relevant technical field. Although this specification has described the present invention in detail with reference to the above embodiments, those of ordinary skill in the art should understand that those skilled in the relevant technical field can still modify the present invention or make equivalent replacements, and all technical solutions and their improvements that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. An exhaust aftertreatment device, characterized in that, it includes a first aftertreatment component and a second aftertreatment component arranged side by side with the first aftertreatment component. The first aftertreatment component includes a first carrier component, an exhaust inlet pipe located on one side of the first carrier component, and a first mixing cavity component located on the other side of the first carrier component; the second aftertreatment component includes a second carrier component, an exhaust outlet pipe located on one side of the second carrier component, and a second mixing cavity component located on the other side of the second carrier component. The first mixing cavity component and the second mixing cavity component are located on the same side of the exhaust aftertreatment device, and the exhaust aftertreatment device is U-shaped; the first mixing cavity component includes a first mixing pipe located therein and a porous pipe at least partially located in the first mixing pipe. The first mixing pipe further includes a plurality of swirl fins distributed circumferentially and slots corresponding to the swirl fins; the second mixing cavity component includes a second mixing pipe located therein and a baffle located in the second mixing pipe. The baffle is provided with a plurality of first openings for urea fragmentation, and the second mixing pipe is provided with a plurality of second openings distributed on its peripheral wall; the porous pipe further extends into the second mixing pipe and is located upstream of the baffle; the first mixing pipe and the second mixing pipe are detachably connected by a clamp to detachably connect the first mixing cavity component and the second mixing cavity component together.

2. The exhaust aftertreatment device according to claim 1, characterized in that: the first mixing cavity component is provided with a top wall, and the top wall is provided with a spray hole for a urea nozzle to spray urea droplets into the porous pipe.

3. The exhaust aftertreatment device according to claim 2, characterized in that: the first mixing pipe includes a conical portion, and the swirl fins and the slots are both provided on the conical portion; one end of the porous pipe is close to the spray hole.

4. The exhaust aftertreatment device according to claim 1, characterized in that: the second mixing pipe is provided with an arc-shaped end bowl at the bottom for forcing the air flow to reverse.

5. The exhaust aftertreatment device according to claim 4, characterized in that: the second mixing cavity component includes an arc-shaped end cover located on the side for guiding the air flow coming out of the second mixing pipe to the second carrier component.

6. The exhaust aftertreatment device according to claim 1, characterized in that: the first mixing pipe extends beyond the first mixing cavity component, and the second mixing pipe extends beyond the second mixing cavity component.

7. The exhaust aftertreatment device according to claim 1, characterized in that: the first carrier component includes a diesel oxidation catalyst and a diesel particulate filter located downstream of the diesel oxidation catalyst, and the second carrier component includes a selective catalytic reducer.

8. The exhaust aftertreatment device according to claim 1, characterized in that: The first mixing cavity assembly includes a first annular cavity located between the first mixing pipe and the porous pipe, the second mixing cavity assembly includes a second annular cavity located between the second mixing pipe and the porous pipe, and the first annular cavity communicates with the second annular cavity.

Images