WO2019140895A1

WO2019140895A1 - Exhaust gas aftertreatment device

Info

Publication number: WO2019140895A1
Application number: PCT/CN2018/100395
Authority: WO
Inventors: 王聪; 李军良; 吴健; 王伟
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2018-01-19
Filing date: 2018-08-14
Publication date: 2019-07-25
Also published as: CN110056412A

Abstract

Disclosed is an exhaust gas aftertreatment device, comprising a first aftertreatment assembly (300), an exhaust gas inlet (301), a second aftertreatment assembly (400), an exhaust gas outlet (401), and a mixing chamber assembly (100). The mixing chamber assembly (100) comprises a first space (51), a second space (52), and a third space (53); the top of the first space (51) is in communication with the third space (53); and the top of the second space (52) is also in communication with the third space (53). The mixing chamber assembly (100) is provided with a first ridge (41) convexly projecting into the third space (53) from the bottom thereof, and a second ridge (42) located below the first ridge (41), with a fourth space (54) being formed between the first ridge (41) and the second ridge (42). By virtue of this exhaust gas aftertreatment device, the evaporation distance and time of urea are increased, and the mixing uniformity of a gas flow is improved.

Description

Exhaust aftertreatment device

The present application claims the priority of the Chinese Patent Application Serial No. PCT-A----------

Technical field

The invention relates to an exhaust gas aftertreatment device, and belongs to the technical field of engine exhaust aftertreatment.

Background technique

Studies have shown that the uniformity of ammonia distribution in the exhaust aftertreatment system (eg, selective catalytic reduction system, SCR system) has an important impact on the overall performance and durability of the system. If the distribution of ammonia (NH ₃ ) is uneven, the nitrogen oxide (NOx) conversion efficiency is too low, and if the urea injection amount is increased in order to satisfy the discharge performance, ammonia leakage contamination is likely to occur. At the same time, the urea droplets are easily deposited when they are exposed to a wall surface having a relatively low temperature, and when the crystal is severely formed, the exhaust pipe is blocked, resulting in a decrease in engine power performance. Increasing the mixing uniformity of ammonia molecules can effectively improve the urea utilization rate and reduce the urea injection amount, thereby reducing the risk of urea crystallization.

Therefore, it is necessary to provide an exhaust aftertreatment device capable of improving the mixing uniformity of ammonia molecules to solve the above technical problems.

Summary of the invention

An object of the present invention is to provide an exhaust aftertreatment device capable of uniformly mixing an exhaust gas of an engine with urea droplets.

To achieve the above object, the present invention adopts the following technical solution: an exhaust aftertreatment device including a first aftertreatment assembly, an exhaust inlet in communication with the first aftertreatment assembly, and the first aftertreatment a second aftertreatment component arranged side by side of the assembly, an exhaust outlet in communication with the second aftertreatment component, and a mixing chamber assembly connecting the first and second aftertreatment components, the mixing chamber assembly including a housing and a mixer located within the housing, wherein the housing is provided with a first opening, a second opening located beside the first opening, and a urea nozzle for mounting urea droplets onto the mixer a mount comprising a first inlet and a second inlet in communication with the first opening, a first space on an inner side of the first inlet, and a second inner side on the second inlet a space and a third space between the first space and the second space; the mixer includes a first dividing wall between the first inlet and the first space and located at the Second import a second partition wall between the second space, the first partition wall is provided with a plurality of first openings communicating with the first inlet and the first space, and the second partition wall is provided with communication a plurality of second openings of the second inlet and the second space; a top of the first space is in communication with the third space, and a top of the second space is also connected to the third space The mixer is provided with a first ridge protruding into the third space and a second ridge below the first ridge to be at the first ridge and the second ridge Forming a fourth space between the portions; the first raised portion is provided with a first side and a second side, and the first side is provided with a plurality of first connecting the third space and the fourth space Perforating, the second side is provided with a plurality of second perforations communicating with the third space and the fourth space, the fourth space entering the second opening from both sides in a manner of forming a double swirl .

As a further improved technical solution of the present invention, the mixer is provided with a first curved wall fixed to the first partition wall, and the first curved wall includes a first inner side of the first partition wall In one part, the first space is located between the first portion and the first partition wall; a first swirl direction is defined between the first portion and the first partition wall.

As a further improved technical solution of the present invention, the mixer is provided with a second curved wall fixed to the second partition wall, and the second curved wall includes a second inner side of the second partition wall a second portion, the second space is located between the second portion and the second partition wall; a second swirl direction is defined between the second portion and the second partition wall; One swirling direction is one of clockwise or counterclockwise, and the second swirling direction is the other of clockwise or counterclockwise.

As a further improvement of the present invention, the first curved wall further includes a first extending portion extending from the first portion in a reverse direction, the first extending portion being directly or indirectly fixed to an inner wall of the housing, Having the first inlet sealed therein; the second curved wall further includes a second extension extending in a reverse direction from the second portion, the second extension being directly or indirectly fixed to the housing The inner wall is such that the second inlet is sealed therein.

As a further improvement of the present invention, the fourth space further extends between the first extension and the second elevation and between the second extension and the second elevation.

As a further improved technical solution of the present invention, the fourth space further defines a third swirling direction and a fourth swirling direction, wherein the third swirling direction is substantially the same as the second swirling direction, The fourth swirl direction is substantially the same as the first swirl direction.

As a further improvement of the present invention, the first ridge portion includes a first top edge connecting the first side edge and the second side edge; the second ridge portion includes a third side edge, a fourth side opposite to the third side and a second top side connecting the third side and the fourth side; the angle between the first side and the second side is an acute angle The angle between the third side and the fourth side is an acute angle.

As a further improvement of the present invention, the first side is fixed on the first curved wall, and the second side is fixed on the second curved wall.

As a further improved technical solution of the present invention, the mixing chamber assembly further includes a blocking piece that blocks the first space, the second space, the third space, and the fourth space in an exhaust gas entering direction, A flow of air is forced from the first inlet and the second inlet.

As a further improved technical solution of the present invention, the exhaust aftertreatment device has a U shape, and the first aftertreatment component includes a diesel oxidation catalyst and a diesel particulate trap located downstream of the diesel oxidation catalyst, the first The secondary aftertreatment component includes a selective catalytic reducing agent.

In contrast to the prior art, the present invention provides a fourth space between the first raised portion and the second raised portion by providing a second raised portion. This arrangement makes full use of the cross section, increases the distance and time of urea evaporation, improves the uniformity of airflow mixing, and improves the resistance to crystallization.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an exhaust aftertreatment device of the present invention.

Figure 2 is a perspective view of another angle of Figure 1.

Fig. 3 is a front view of Fig. 2;

Figure 4 is a rear elevational view of Figure 2.

Figure 5 is a plan view of Figure 2 .

Figure 6 is a bottom plan view of Figure 2 .

Figure 7 is a left side view of Figure 2.

Figure 8 is a right side view of Figure 2.

Figure 9 is a schematic cross-sectional view taken along line A-A of Figure 7.

Figure 10 is a cross-sectional view taken along line B-B of Figure 5.

Figure 11 is a partially exploded view of Figure 1.

Figure 12 is a partially exploded view of another angle of Figure 11;

Figure 13 is a further exploded perspective view of Figure 12 .

Figure 14 is an exploded perspective view of the mixing chamber assembly.

Figure 15 is a perspective view of the mixing chamber assembly.

Figure 16 is a perspective view of another angle of Figure 15.

Figure 17 is a front elevational view of Figure 15.

Figure 18 is a rear elevational view of Figure 15.

Figure 19 is a perspective view showing the housing of Figure 15 removed.

Fig. 20 is a partially exploded perspective view of Fig. 15;

Figure 21 is a further exploded perspective view of Figure 20.

Figure 22 is a schematic cross-sectional view taken along line C-C of Figure 16 and showing the direction of rotation of the gas stream.

Detailed ways

Referring to FIG. 1 to FIG. 22, the present invention discloses an exhaust aftertreatment device 200 including a first aftertreatment assembly 300, an exhaust inlet 301 in communication with the first aftertreatment assembly 300, and a second aftertreatment component 400 in which the first aftertreatment assembly 300 is arranged side by side, an exhaust outlet 401 in communication with the second aftertreatment component 400, and an interface connecting the first and

second aftertreatment components

300, 400 The mixing chamber assembly 100. In the illustrated embodiment of the invention, the exhaust aftertreatment device 200 is U-shaped, and the first aftertreatment assembly 300 includes a diesel oxidation catalyst (DOC) and diesel particulates located downstream of the diesel oxidation catalyst. A collector (DPF), the second aftertreatment component 400 comprising a selective catalytic reducing agent (SCR).

The mixing chamber assembly 100 includes a housing 1 and a mixer 2 mounted within the housing 1.

In the illustrated embodiment of the present invention, the housing 1 is provided with a first baffle 11, a second baffle 12 opposite to the first baffle 11 and surrounding the first baffle 11 and the The outer casing 13 of the second baffle 12. The first baffle 11 is provided with a first opening 111 and a second opening 112 located below the first opening 111 . The first opening 111 is for supplying airflow, and the second opening 112 is for supplying airflow. A mount 131 is welded to the top of the outer casing 13. The mount 131 is for mounting a urea nozzle (not shown) to inject urea into the mixer 2.

The mixer 2 includes a first inlet 201 and a second inlet 202 in communication with the first opening 111. Referring to FIG. 19 to FIG. 22, the mixer 2 includes a first partition wall 21 and a second partition wall 22 respectively located at two sides of the first opening 111, and the first branch. a first curved wall 31 to which the partition wall 21 is fixed, and a second curved wall 32 fixed to the second partition wall 22, located inside the first curved wall 31 and opposite to the first A first raised portion 41 to which the second

curved walls

31, 32 are fixed, and a second raised portion 42 located below the first raised portion 41.

In the illustrated embodiment of the invention, the first curved wall 31 includes a first portion 311 located inside the first partition wall 21 and a first extension portion 312 extending in a reverse direction from the first portion 311. The first extension portion 312 is directly or indirectly fixed to the inner wall of the housing 1 such that the first inlet 201 is sealed therein. Similarly, the second curved wall 32 includes a second portion 321 located on an inner side of the second partition wall 22 and a second extension portion 322 extending in a reverse direction from the second portion 321 . The second extension 322 is directly or indirectly fixed to the inner wall of the housing 1 such that the second inlet 202 is sealed therein.

Referring to FIG. 22, the mixer 2 includes a first space 51 between the first partition wall 21 and the first portion 311, and a second portion between the second partition wall 22 and the second portion 321 The second space 52 is located in the third space 53 between the first space 51 and the second space 52. The first space 51 is located inside the first inlet 201; the second space 52 is located inside the second inlet 202. The first raised portion 41 and the second raised portion 42 protrude from the bottom into the third space 53 , and a fourth space is formed between the first raised portion 41 and the second raised portion 42 . 54. The first partition wall 21 is provided with a plurality of first openings 211 communicating with the first inlet 201 and the first space 51, and the second partition wall 22 is provided to communicate with the second inlet 202 and a plurality of second openings 221 of the second space 52; a top of the first space 51 is in communication with the third space 53, and a top of the second space 52 is also connected to the third space 53 . A first swirl direction S1 is defined between the first portion 311 and the first partition wall 21; a second swirl direction S2 is defined between the second portion 321 and the second partition wall 22. Wherein, the first swirling direction S1 is one of clockwise or counterclockwise, and the second swirling direction S2 is the other of clockwise or counterclockwise. Referring to the hollow arrows in FIG. 22, in the illustrated embodiment of the present invention, the first swirl direction S1 is a clockwise direction, and the second swirl direction S2 is a counterclockwise direction. With such a setting, the cross section of the mixing chamber assembly 100 can be fully utilized to increase the mixing distance between the urea and the exhaust gas in a manner of forming a double swirling flow, improve the uniformity of evaporation and mixing of the urea, and have strong anti-crystallization ability.

The first ridge 41 is provided with a first side 411 and a second side 412. The first side 411 is provided with a plurality of first through holes 4111 communicating with the third space 53 and the fourth space 54. The second side 412 is provided with a plurality of second through holes 4121 that communicate with the third space 53 and the fourth space 54. The fourth space 54 further extends between the first extension 312 and the second ridge 42 and between the second extension 322 and the second ridge 42. The fourth space 54 communicates with the second opening 112 to form a double swirl. The fourth space further defines a third swirl direction S3 and a fourth swirl direction S4, wherein the third swirl direction S3 is substantially the same as the second swirl direction S2, the fourth swirl direction S4 is substantially the same as the first swirl direction S1.

The first ridge 41 includes a first top edge 413 connecting the first side 411 and the second side 412; the second ridge 42 includes a third side 421, and the third a fourth side 422 opposite to the side 421 and a second top side 423 connecting the third side 421 and the fourth side 422; the first side 411 and the second side 412 The angle between the third side 421 and the fourth side 422 is an acute angle.

The first side 411 is fixed to the first curved wall 31, and the second side 412 is fixed to the second curved wall 32.

The mixing chamber assembly 100 further includes a flap 6 that blocks the first space 51, the second space 52, the third space 53, and the fourth space 54 in an exhaust gas inflow direction, forcing airflow from The first inlet 201 and the second inlet 202 enter.

During use, when the exhaust of the engine enters the mixing chamber assembly 100, the exhaust gas enters the housing 1 from the first and

second inlets

201, 202 due to the blocking of the blocking piece 6; The gas passes through the first opening 211 and the second opening 221 into the first space 51 and the second space 52, respectively; subsequently, the exhaust gas is separated from the first swirling direction S1 and the second swirling direction S2 respectively The side is rotated into the third space 53; when the injection condition is satisfied, the urea nozzle injects urea into the third space 53, the atomized urea droplet is mixed with the exhaust of the engine, and passes through the first and

second perforations

4111, 4121 enter the fourth space 54. Referring to FIG. 22, the mixture of urea droplets and the exhaust of the engine enters the second opening 112 in a manner of forming a double swirl in the third swirl direction S3 and the fourth swirl direction S4.

It should be noted that the orientations of "upper", "lower", "top", "bottom", "below" and the like described in the present invention should not be construed as limited, because these positions are different depending on the position of the components. Relationships should also be adaptively understood. In addition, the above embodiments are only intended to illustrate the present invention and do not limit the technical solutions described in the present invention, and the understanding of the present specification should be based on those skilled in the art. Although the present invention has been described in detail with reference to the embodiments of the present invention, it will be understood by those skilled in the art that the invention may be modified or equivalently substituted without departing from the invention. The spirit and scope of the invention and its modifications are intended to be included within the scope of the appended claims.

Claims

An exhaust aftertreatment device including a first aftertreatment assembly, an exhaust inlet in communication with the first aftertreatment assembly, a second aftertreatment assembly disposed side by side with the first aftertreatment assembly, and An exhaust outlet in communication with the second aftertreatment component and a mixing chamber assembly connecting the first and second aftertreatment components, the mixing chamber assembly including a housing and a mixer located within the housing, wherein The housing is provided with a first opening, a second opening on the side of the first opening, and a mount for mounting a urea nozzle to inject urea droplets onto the mixer, characterized in that the mixer a first inlet and a second inlet in communication with the first opening, a first space on an inner side of the first inlet, a second space on an inner side of the second inlet, and a first space in the first space a third space between the second space; the mixer includes a first dividing wall between the first inlet and the first space and a second inlet and the second space Second separation between The first partition wall is provided with a plurality of first openings communicating with the first inlet and the first space, and the second partition wall is provided with a plurality of the second inlet and the second space a second opening; a top of the first space is in communication with the third space, a top of the second space is also in communication with the third space; the mixer is provided with a protrusion into the first a first ridge in the three spaces and a second ridge below the first ridge to form a fourth space between the first ridge and the second ridge; the first ridge a first side and a second side, the first side is provided with a plurality of first perforations communicating with the third space and the fourth space, and the second side is provided with the communication a third space and a plurality of second perforations of the fourth space, the fourth space entering the second opening from both sides in a manner to form a double swirl.
The exhaust aftertreatment device according to claim 1, wherein said mixer is provided with a first curved wall fixed to said first partition wall, said first curved wall comprising said a first portion of the inner side of the first dividing wall, the first space being located between the first portion and the first dividing wall; a first swirling direction defined between the first portion and the first dividing wall .
The exhaust aftertreatment device according to claim 2, wherein said mixer is provided with a second curved wall fixed to said second partition wall, said second curved wall comprising said a second portion of the inner side of the second dividing wall, the second space being located between the second portion and the second dividing wall; a second defined between the second portion and the second dividing wall a swirling direction; wherein the first swirling direction is one of clockwise or counterclockwise, and the second swirling direction is the other of clockwise or counterclockwise.
The exhaust aftertreatment device according to claim 3, wherein said first curved wall further comprises a first extension extending in a reverse direction from said first portion, said first extension being directly or indirectly fixed The inner wall of the housing is such that the first inlet is sealed therein; the second curved wall further includes a second extension extending in opposite directions from the second portion, the second extension being directly Or indirectly fixed to the inner wall of the housing such that the second inlet is sealed therein.
The exhaust aftertreatment device according to claim 4, wherein said fourth space further extends between said first extension and said second elevation and said second extension and said Between the second ridges.
The exhaust aftertreatment device according to claim 3, wherein said fourth space further defines a third swirl direction and a fourth swirl direction, wherein said third swirl direction is opposite said second The swirl directions are substantially the same, and the fourth swirl direction is substantially the same as the first swirl direction.
The exhaust aftertreatment device according to claim 3, wherein said first ridge portion includes a first top edge connecting said first side edge and said second side edge; said second ridge portion a third side, a fourth side opposite the third side, and a second top side connecting the third side and the fourth side; the first side and the first side The angle between the two sides is an acute angle, and the angle between the third side and the fourth side is an acute angle.
The exhaust aftertreatment device according to claim 7, wherein said first side is fixed to said first curved wall, and said second side is fixed to said second curved wall .
The exhaust aftertreatment device according to any one of claims 1 to 8, wherein the mixing chamber assembly further comprises shielding the first space, the second space, in an exhaust gas entering direction, The third space and the baffle of the fourth space force airflow from the first inlet and the second inlet.
The exhaust aftertreatment device according to claim 1, wherein said exhaust aftertreatment device is U-shaped, said first aftertreatment assembly comprising a diesel oxidation catalyst and diesel fuel downstream of said diesel oxidation catalyst A particle trap, the second aftertreatment component comprising a selective catalytic reducing agent.