WO2019144602A1

WO2019144602A1 - Exhaust aftertreatment device

Info

Publication number: WO2019144602A1
Application number: PCT/CN2018/100408
Authority: WO
Inventors: 于百战; 李伟; 吕春虎
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2018-01-26
Filing date: 2018-08-14
Publication date: 2019-08-01
Also published as: CN110080861A

Abstract

An exhaust aftertreatment device, the exhaust aftertreatment device comprising a mixing chamber assembly (100). The mixing chamber assembly (100) comprises a housing (1) and a mixing device (2) located in the housing (1), wherein the housing (1) comprises an inner cavity (11) and a partition plate (12) fixed in the inner cavity (11). The partition plate (12) partitions the inner cavity (11) into a first cavity (111) and a second cavity (112). The mixing device (2) comprises a first mixing tube (21) located in the inner cavity (11) and a porous tube (22) located in the first mixing tube (21). The first mixing tube (21) further comprises a swirl portion (211) and an extension portion (212) extending into the second cavity (112). The swirl portion (211) comprises a plurality of swirl fins (2111). The extension portion (212) is provided with a plurality of first openings (2121) distributed on the peripheral wall thereof. The porous tube (22) is located in the first cavity (111) and the second cavity (112). Such an exhaust aftertreatment device increases the distance and time for urea evaporation, improves the uniformity of gas flow mixing and improves the resistance to crystallization.

Description

Exhaust aftertreatment device

The present application claims the priority of the Chinese Patent Application Serial No. 20, 181, 007, 819, filed on Jan. 26, the entire disclosure of which is hereby incorporated by reference.

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 mixing device located within the housing, wherein the housing is provided with a mount for mounting a urea nozzle to inject urea droplets into the mixing device, the housing including an inner cavity and being fixed in the inner cavity a partition in the body, the partition separating the inner cavity into a first cavity in communication with the first aftertreatment component and a second cavity in communication with the second aftertreatment component, The mixing device includes a first mixing tube located in the inner cavity and a porous tube located within the first mixing tube, the first mixing tube further including a swirling portion located in the first cavity Extending into the second An extension in the body, the swirl portion including a plurality of swirl fins distributed in a circumferential direction and a groove corresponding to the swirl fin; the extension portion is provided with a plurality of first ones distributed on a peripheral wall thereof Opening a hole; the porous tube is located in the first cavity and the second cavity.

As a further improved technical solution of the present invention, the exhaust gas aftertreatment device has a U shape.

As a further improved technical solution of the present invention, the swirling portion has a tapered shape.

As a further improved technical solution of the present invention, one end of the porous tube is adjacent to the mount.

As a further improved technical solution of the present invention, the extension portion is provided with an arcuate end bowl at the bottom and for forcing the airflow to reverse.

As a further improved technical solution of the present invention, the partition is provided with a perforation through which the first mixing tube passes.

As a further improved technical solution of the present invention, the first aftertreatment component includes a diesel oxidation catalyst and a diesel particulate trap located downstream of the diesel oxidation catalyst, and the second aftertreatment component includes a selective catalytic reducing agent.

As a further improved technical solution of the present invention, the mixing device includes a baffle fixed in the first mixing tube, the baffle is provided with a plurality of crushing holes for urea crushing, and the porous pipe extends to the block The upstream of the piece.

Compared with the prior art, the present invention increases the distance and time of urea evaporation by providing the first mixing tube and the porous tube, improves the uniformity of airflow mixing, and improves the anti-crystallization ability.

DRAWINGS

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

Fig. 2 is an exploded perspective view of Fig. 1;

Figure 3 is a cross-sectional view taken along line A-A of Figure 1.

Figure 4 is a further exploded perspective view of Figure 2.

Detailed ways

Referring to Figures 1 to 4, 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 mixing device 2 located within the housing 1, wherein the housing 1 is provided with an installation for mounting a urea nozzle 4 to inject urea droplets into the mixing device 2. Block 5.

The housing 1 includes an inner cavity 11 and a partition 12 fixed in the inner cavity 11, the partition 12 separating the inner cavity 11 into communication with the first aftertreatment component 300 The first cavity 111 and the second cavity 112 in communication with the second aftertreatment component 400.

The mixing device 2 comprises a first mixing tube 21 located in the inner chamber 11 and a perforated tube 22 located in the first mixing tube 21. The first mixing tube 21 further includes a swirling portion 211 located in the first cavity 111 and an extending portion 212 extending into the second cavity 112. In the illustrated embodiment of the invention, the swirl portion 211 is tapered, including a plurality of swirl fins 2111 distributed circumferentially and a slot 2112 corresponding to the swirl fins 2111. The extension portion 212 is provided with a plurality of first openings 2121 distributed on the peripheral wall thereof; the porous tube 22 is located in the first cavity 111 and the second cavity 112. One end of the porous tube 22 is adjacent to the mount 5. The extension 212 is provided with an arcuate end bowl 2122 at the bottom and used to force the flow of gas to reverse. The partition 12 is provided with a through hole 121 through which the first mixing tube 21 passes. The mixing device 2 includes a flap 23 fixed in the first mixing tube 21, the flap 23 being provided with a plurality of crushing holes 231 for urea breaking, the porous tube 22 extending to the flap 23 Upstream. In addition, the flap 23 is capable of preventing excessive urea from being directly sprayed on the curved end bowl 2122 to form crystals.

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 mixing device located within the housing, wherein The housing is provided with a mount for mounting a urea nozzle to inject urea droplets into the mixing device, wherein the housing includes an inner cavity and a partition fixed in the inner cavity, a partition separating the inner cavity into a first cavity in communication with the first aftertreatment component and a second cavity in communication with the second aftertreatment component, the mixing device including a first mixing tube in the inner cavity and a porous tube located in the first mixing tube, the first mixing tube further comprising a swirling portion in the first cavity and extending into the second cavity Extension in the middle a plurality of swirl fins distributed in a circumferential direction and a groove corresponding to the swirl fin; the extension portion is provided with a plurality of first openings distributed on a peripheral wall thereof; the porous tube is located at the first In the cavity and in the second cavity.
The exhaust aftertreatment device according to claim 1, wherein said exhaust aftertreatment device has a U shape.
The exhaust aftertreatment device according to claim 1, wherein said swirling portion has a tapered shape.
The exhaust aftertreatment device according to claim 1, wherein one end of said porous tube is adjacent to said mount.
The exhaust aftertreatment device of claim 1 wherein said extension is provided with an arcuate end bowl at the bottom for forcing the flow of gas to reverse.
The exhaust aftertreatment device according to claim 1, wherein said partition is provided with a perforation through which said first mixing tube passes.
The exhaust aftertreatment device of claim 1 wherein said first aftertreatment component comprises a diesel oxidation catalyst and a diesel particulate trap downstream of said diesel oxidation catalyst, said second aftertreatment The assembly includes a selective catalytic reducing agent.
The exhaust aftertreatment device according to claim 1, wherein said mixing means comprises a baffle fixed in said first mixing pipe, said baffle being provided with a plurality of crushing holes for urea breaking, The porous tube extends upstream of the flap.