WO2017206946A1

WO2017206946A1 - Mixing chamber assembly

Info

Publication number: WO2017206946A1
Application number: PCT/CN2017/086997
Authority: WO
Inventors: 王聪; 赵治国; 韩文军; 孙小冈; 彭宇
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2016-06-03
Filing date: 2017-06-02
Publication date: 2017-12-07
Also published as: CN107461239A

Abstract

A mixing chamber assembly (100) for use in an engine exhaust aftertreatment apparatus. The mixing chamber assembly (100) comprises a chamber (101) and a mounting hole (1213) for mounting a urea nozzle. The chamber (101) comprises a first sub-chamber (10) for use in communication with a first aftertreatment part (200), a second sub-chamber (20) for use in communication with a second aftertreatment part (300), and an intermediate sub-chamber (30). The urea nozzle is used for spraying urea droplets into the first sub-chamber (10). The mixing chamber assembly (100) further comprises a mixer (40) located in the intermediate sub-chamber. The mixer (40) is provided with a first row of fins (41) and a second row of fins (42) in a thickness direction perpendicular to an exhaust flow direction, wherein inclination directions of the first row of fins (41) and the second row of fins (42) cross each other. The mixing chamber assembly (100) improves the mixing between urea droplets and exhaust, improves the evaporation rate of urea droplets, and reduces the risk of urea crystallization.

Description

Mixing chamber assembly

The present application claims priority to Chinese Patent Application No. Serial No. No. No. No. No. No. No. No. No. No. No. No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No

Technical field

The invention relates to a mixing chamber assembly, belonging 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 a mixing chamber assembly capable of improving the mixing uniformity of ammonia molecules to solve the above technical problems.

Summary of the invention

It is an object of the present invention to provide a mixing chamber assembly that is capable of mixing the exhaust of an engine with urea droplets.

To achieve the above object, the present invention adopts the following technical solution: a mixing chamber assembly for use in an engine exhaust aftertreatment device, the mixing chamber assembly including a cavity and a mounting hole for mounting a urea nozzle, the cavity a first sub-cavity for communicating with the first post-processing component, a second sub-cavity for communicating with the second post-processing component, and a first sub-cavity and the second sub-cavity a middle sub-cavity, wherein the first sub-cavity is located upstream of the exhaust gas flow direction than the second sub-cavity, and the urea nozzle is configured to inject urea droplets into the first sub-cavity The mixing chamber assembly further includes a mixer located in the intermediate sub-cavity, the mixer being provided with a first row of fins and a second row of fins in a thickness direction perpendicular to a direction of flow of the exhaust gas, wherein The oblique directions of the first row of fins and the second row of fins cross each other.

As a further improved technical solution of the present invention, the mixer is provided with a frame for fixing the first row of fins and the second row of fins, the frame is provided with a first upper surface and through the first a plurality of chutes of the upper surface, the chute including a first chute for inserting the first row of fins and a second chute for inserting the second row of fins.

As a further improved technical solution of the present invention, the mixer includes a partition plate located in the frame, the partition plate is provided with a second upper surface and a plurality of oblique grooves penetrating the second upper surface, the inclined The groove includes a third chute for inserting the first row of fins and a fourth chute for inserting the second row of fins, wherein two ends of the first row of fins are respectively inserted into the first slot In the chute and the third chute, two ends of the second row of fins are respectively inserted into the second chute and the fourth chute.

As a further improvement of the technical solution of the present invention, the first row of fins are perpendicular to the second row of fins, and the first row of fins and the second row of fins are not upwardly beyond the first Upper surface and second upper surface.

As a further improved technical solution of the present invention, the mixer further has a third row of fins and a fourth row of fins in a thickness direction perpendicular to the flow direction of the exhaust gas, wherein the third row of fins and The fourth row of fins are located below the first row of fins and the second row of fins, and the third row of fins and the fourth row of fins extend in a vertical direction.

As a further improved technical solution of the present invention, the frame is provided with a first lower surface and a plurality of vertical grooves extending through the first lower surface, the vertical grooves including a first for inserting the third row of fins a vertical slot and a second vertical slot for insertion of the fourth row of fins.

As a further improved technical solution of the present invention, the partition plate is provided with a second lower surface and a plurality of vertical grooves extending through the second lower surface, the vertical grooves including the third row of fins inserted a third vertical slot and a fourth vertical slot for insertion of the fourth row of fins, wherein two ends of the third row of fins are respectively inserted into the first vertical slot and the third vertical slot In the slot, two ends of the fourth row of fins are respectively inserted into the second vertical slot and the fourth vertical slot.

As a further improvement of the present invention, the third row of fins and the fourth row of fins do not extend downward beyond the first lower surface and the second lower surface.

As a further improved technical solution of the present invention, the mixing chamber assembly includes a main body portion and a cover plate that cooperates with the main body portion, the main body portion includes a side plate and a side wall extending from the side plate, the cover a plate is fixed on the side wall, the first sub-cavity, the second sub-cavity and the intermediate sub-cavity are formed by the main body portion and the cover plate; the cover plate includes the first sub-chamber a cavity communicating and corresponding to the first opening of the first after-treatment component and a second opening communicating with the second sub-cavity and corresponding to the second after-treatment component, the mounting hole being located on the side The top of the wall.

As a further improved technical solution of the present invention, the first sub-cavity and the second sub-cavity are mutually offset; in the thickness direction, the mixing cavity assembly is disposed in the first sub-cavity An inclined portion with the second sub-cavity to form a constriction corresponding to the mixer.

As a further improved technical solution of the present invention, the mixing chamber assembly includes the first post-processing component and the first A baffle between the sub-chambers, the baffle being provided with a plurality of perforations.

Compared with the prior art, the present invention forms a better swirling effect by providing a first row of fins and a second row of fins which are double-layered and intersect in an oblique direction. This arrangement increases the stroke of the airflow in a limited space, ensures that the urea droplets are thoroughly mixed with the exhaust gas, and ensures that the urea droplets are sufficiently heated, thereby increasing the evaporation rate of the urea droplets, improving the uniformity of ammonia molecular distribution, and reducing the urea crystallization. risks of.

DRAWINGS

1 is a perspective view of the mixing chamber assembly of the present invention assembled with a first aftertreatment component and a second aftertreatment component.

Figure 2 is a partial exploded perspective view of Figure 1 with the mixing chamber assembly separated.

Figure 3 is a partial exploded perspective view of the mixing chamber assembly of Figure 2 with the cover and baffle separated.

Figure 4 is a further exploded perspective view of Figure 3 with the mixer also separated.

Figure 5 is a perspective view of the mixing chamber assembly of Figure 2 at another angle.

Figure 6 is a front elevational view of the mixing chamber assembly of Figure 2.

Figure 7 is a side view of Figure 6.

Figure 8 is a perspective view of the mixing chamber assembly of Figure 2 with the cover removed.

Figure 9 is a front elevational view of Figure 8.

Figure 10 is a perspective view of the cover of Figure 8 after removal, and schematically indicating the position of the urea nozzle and the direction of the engine's exhaust and urea droplets double swirl.

Figure 11 is a perspective view of the mixer of Figure 8.

Fig. 12 is an exploded perspective view of Fig. 11;

Figure 13 is a front elevational view of the partition of Figure 12.

detailed description

Referring to Figures 1 through 10, the present invention discloses a mixing chamber assembly 100 for use in an engine exhaust aftertreatment device to treat engine exhaust. The exhaust aftertreatment device may include a first aftertreatment component 200 located upstream of the mixing chamber assembly 100 and/or a second aftertreatment component 300 located downstream of the mixing chamber assembly 100. Wherein, the first aftertreatment component 200 may be an oxidation catalyst (DOC) or a combination of a DOC and a diesel particulate trap (DPF), and the second aftertreatment component 300 may be a selective catalytic reduction module (SCR). Of course, in some embodiments, a DPF coated with an SCR catalyst can also be used. (SDPF) instead of DPF. The shape of the exhaust aftertreatment device may be linear, U-shaped, Z-shaped, L-shaped, or the like. In addition, those skilled in the art can understand that the above-mentioned DOC, DPF, SDPF, etc. can be designed as other types of catalysts or combinations according to actual needs, and details are not described herein again.

Referring to FIGS. 2-10, the mixing chamber assembly 100 includes a cavity 101 and a mixer 40 located within the cavity 101. According to different partitions, the cavity 101 includes a first sub-cavity 10, a second sub-cavity 20, and a middle sub-cavity 30 connecting the first sub-cavity 10 and the second sub-cavity 20. The first sub-cavity 10 is located upstream of the exhaust gas flow direction than the second sub-cavity 20, and the mixer 40 is located in the intermediate sub-cavity 30.

Structurally, as shown in FIGS. 5 and 7, the mixing chamber assembly 100 of the present invention includes a body portion 1 and a cover plate 2 that mates with the body portion 1. The body portion 1 includes a side panel 11 and a side wall 12 extending from the side panel 11. The cover plate 2 is fixed to the side wall 12 by, for example, welding. In the illustrated embodiment of the invention, the first sub-cavity 10, the second sub-cavity 20, and the intermediate sub-cavity 30 are formed by the main body portion 1 and the cover plate 2.

Specifically, as shown in FIG. 9 , the sidewall 12 includes a first sidewall 121 at least partially forming the first sub-cavity 10 , and a second sidewall at least partially forming the second sub-cavity 20 . 122 and a third sidewall 123 at least partially forming the intermediate sub-cavity 30, wherein the first sidewall 121 includes a first left side wall 1211 and a first right side wall 1212, and the second sidewall 122 includes The second left side wall 1221 and the second right side wall 1222 include a third left side wall 1231 and a third right side wall 1232. In the illustrated embodiment of the present invention, the first left side wall 1211 is provided with a mounting hole 1213 for mounting a urea nozzle at a position near the top thereof. The mounting hole 1213 is located at the upper left of the mixing chamber assembly 100, that is, at an angle to the center plane of the mixing chamber assembly 100.

Referring to FIG. 7, the first sub-cavity 10 and the second sub-cavity 20 are offset from each other. The mixing chamber assembly 100 is provided with an inclined portion 50 between the first sub-cavity 10 and the second sub-cavity 20 in a thickness direction AA perpendicular to the exhaust gas flow direction to form a corresponding portion The neck 51 of the mixer 40.

Referring to FIG. 2 to FIG. 4 , the cover plate 2 includes a first plate portion 21 , a second plate portion 22 , and a tilt connecting the first plate portion 21 and the second plate portion 22 . Face 23. The inclined surface portion 23 corresponds to the inclined portion 50. In addition, the first plate portion 21 is provided with a first opening 211 communicating with the first sub-cavity 10 and corresponding to the first post-processing component 200, and the second plate portion 22 is provided with the The second sub-cavity 20 is in communication and corresponds to the second opening 221 of the second after-treatment component 300. In the illustrated embodiment of the invention, the first opening 211 is an upstream exhaust inlet and the second opening 221 is a downstream exhaust outlet.

Referring to FIG. 8 to FIG. 13 , the mixer 40 is provided with a first row of fins 41 , a second row of fins 42 , a third row of fins 43 and a fourth row of fins 44 , wherein the first The fins 41 and the second row of fins 42 are located at the upper end, and the third row of fins 43 and the fourth row of fins 44 are located at the lower end. The oblique directions of the first row of fins 41 and the second row of fins 42 cross each other, and the third row of fins 43 and the fourth row of fins 44 extend in the vertical direction. In the illustrated embodiment of the invention, the first row of fins 41 are perpendicular to the second row of fins 42.

The mixer 40 is provided with a frame 45 for fixing the above fins and a partition 46 located inside the frame 45. The frame 45 has a trapezoidal shape, and is provided with a first upper surface 451, a plurality of chutes 452 extending through the first upper surface 451, a first lower surface 453, and a plurality of vertical slots 454 extending through the first lower surface 453. . The chute 452 includes a first chute 4521 for inserting the first row of fins 41 and a second chute 4522 for inserting the second row of fins 42. The vertical slot 454 includes a first vertical slot 4541 for insertion of the third row of fins 43 and a second vertical slot 4542 for insertion of the fourth row of fins 44.

Referring to FIG. 13 , the partition 46 is provided with a second upper surface 461 , a plurality of oblique grooves 462 extending through the second upper surface 461 , a second lower surface 463 , and a second lower surface 463 . A number of vertical grooves 464. The oblique groove 462 includes a third chute 4621 into which the first row of fins 41 is inserted and a fourth chute 4622 into which the second row of fins 42 are inserted. The vertical groove 464 includes a third vertical groove 4641 into which the third row of fins 43 is inserted and a fourth vertical groove 4642 into which the fourth row of fins 44 are inserted. The two ends of the first row of fins 41 are respectively inserted into the first chute 4521 and the third chute 4621. The two ends of the second row of fins 42 are respectively inserted into the second chute 4522 and the fourth chute 4622. Two ends of the third row of fins 43 are respectively inserted into the first vertical groove 4541 and the third vertical groove 4641, and two ends of the fourth row of fins 44 are respectively inserted into the second vertical row Straight groove 4542 and the fourth vertical groove 4642.

Referring to FIG. 9 , the first row of fins 41 and the second row of fins 42 do not extend upward beyond the first upper surface 451 and the second upper surface 461 . The third row of fins 43 and the fourth row of fins 44 do not extend downward beyond the first lower surface 453 and the second lower surface 463.

Referring to FIG. 2 to FIG. 6 , the mixing chamber assembly 100 includes a baffle 6 between the first post-processing component 200 and the first sub-cavity 10 , and the baffle 6 is provided with a plurality of baffles 6 . Perforation 61. By providing the baffle 6, the deflection of the exhaust gas from the first after-treatment component 200 directly to the injected urea can be reduced, the mixing of the urea droplets and the exhaust gas can be improved, the evaporation rate of the urea droplets can be improved, and the ammonia distribution can be improved. Uniformity reduces the risk of urea crystallization.

The terms "upper", "lower", "left", "right", "front", "rear", and the like, as used herein, are used to refer to the relative position of the space for the purpose of illustration. The relationship of one feature to another. Can reason The terms of the relative position of the space may be intended to include different orientations other than those shown in the drawings, and should not be construed as limiting the claims. In addition, the descriptor "vertical" as used herein is not exactly equivalent to the direction of gravity, allowing for an angled tilt.

In addition, the above embodiments are only for illustrating the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present specification should be based on those skilled in the art, although the present specification has been carried out with reference to the above embodiments. DETAILED DESCRIPTION OF THE INVENTION However, those skilled in the art should understand that the invention may be modified or equivalently replaced by those skilled in the art without departing from the spirit and scope of the invention. It is intended to be included within the scope of the appended claims.

Claims

A mixing chamber assembly for use in an engine exhaust aftertreatment device, the mixing chamber assembly including a cavity and a mounting hole for mounting a urea nozzle, the cavity including a first line for communicating with the first aftertreatment component a sub-cavity, a second sub-cavity for communicating with the second post-processing component, and a middle sub-cavity connecting the first sub-cavity and the second sub-cavity, the first sub-cavity The urea nozzle is configured to inject urea droplets into the first sub-cavity, in contrast to the second sub-cavity being located upstream of the exhaust gas flow direction, wherein the mixing chamber assembly further comprises a mixer in a middle sub-chamber, the mixer being provided with a first row of fins and a second row of fins in a thickness direction perpendicular to a direction of flow of the exhaust gas, wherein the first row of fins and The oblique directions of the second row of fins cross each other.
A mixing chamber assembly according to claim 1 wherein said mixer is provided with a frame for securing said first row of fins and said second row of fins, said frame being provided with a first upper surface And a plurality of chutes extending through the first upper surface, the chute including a first chute for insertion of the first row of fins and a second chute for insertion of the second row of fins.
The mixing chamber assembly of claim 2 wherein said mixer includes a baffle within said frame, said baffle being provided with a second upper surface and a plurality of slopes extending through said second upper surface a groove including a third chute for inserting the first row of fins and a fourth chute for inserting the second row of fins, wherein both ends of the first row of fins Inserting into the first chute and the third chute respectively, two ends of the second row of fins are respectively inserted into the second chute and the fourth chute.
A mixing chamber assembly according to claim 3, wherein said first row of fins are perpendicular to said second row of fins, and said first row of fins and said second row of fins are not The first upper surface and the second upper surface are upwardly extended.
A mixing chamber assembly according to claim 3, wherein said mixer is further provided with a third row of fins and a fourth row of fins in a thickness direction perpendicular to said exhaust gas flow direction, wherein said The third row of fins and the fourth row of fins are located below the first row of fins and the second row of fins, and the third row of fins and the fourth row of fins are vertical The direction extends.
A mixing chamber assembly according to claim 5 wherein said frame is provided with a first lower surface and a plurality of vertical grooves extending through said first lower surface, said vertical grooves including said third row A first vertical slot into which the fin is inserted and a second vertical slot into which the fourth row of fins are inserted.
The mixing chamber assembly of claim 6 wherein said spacer is provided with a second lower surface and throughout said a plurality of vertical grooves of the lower surface, the vertical grooves including a third vertical groove for insertion of the third row of fins and a fourth vertical groove for insertion of the fourth row of fins, wherein Two ends of the third row of fins are respectively inserted into the first vertical slot and the third vertical slot, and two ends of the fourth row of fins are respectively inserted into the second vertical slot and the Said in the fourth vertical slot.
The mixing chamber assembly of claim 7 wherein said third row of fins and said fourth row of fins do not extend downwardly beyond said first lower surface and said second lower surface.
The mixing chamber assembly of claim 1 wherein said mixing chamber assembly includes a body portion and a cover plate that cooperates with said body portion, said body portion including a side panel and extending from said side panel a side wall, the cover plate is fixed on the side wall, the first sub-cavity, the second sub-cavity and the intermediate sub-cavity are formed by the main body portion and the cover plate; a first opening in communication with the first sub-cavity and corresponding to the first after-treatment component and a second opening in communication with the second sub-cavity and corresponding to the second after-treatment component A mounting hole is located at the top end of the side wall.
The mixing chamber assembly according to claim 9, wherein said first sub-cavity and said second sub-cavity are offset from each other; said mixing chamber assembly is located at said thickness direction An inclined portion between the first sub-cavity and the second sub-cavity is formed to form a constriction corresponding to the mixer.
The mixing chamber assembly of any of claims 1 to 10, wherein the mixing chamber assembly includes a baffle between the first aftertreatment component and the first sub-cavity, The baffle is provided with several perforations.