WO2021212742A1

WO2021212742A1 - Exhaust gas post-treatment package

Info

Publication number: WO2021212742A1
Application number: PCT/CN2020/118241
Authority: WO
Inventors: 王长林; 赵孟东; 叶威
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2020-04-23
Filing date: 2020-09-28
Publication date: 2021-10-28
Also published as: CN212296581U; CN111365107A; CN111779559A

Abstract

An exhaust gas post-treatment package (100), comprising a first post-treatment carrier (11), a second post-treatment carrier (21), a third post-treatment carrier (31), and a mixing assembly (4). The mixing assembly (4) comprises a fourth housing (41), a mixing pipe (42) located in the fourth housing (41), a porous pipe (43) located in the mixing pipe (42), and a reflecting plate (45) located at a lower end of the mixing pipe (42) and spaced from the mixing pipe (42); the fourth housing (41) is provided with a first cavity (411), a second cavity (412), and a partitioning plate (413); the mixing pipe (42) comprises several swirl sheets (421) exposed in the first cavity (411) and several perforations (422) exposed in the second cavity (412). The mixing assembly (4) further comprises a stop plate (46) located in the second cavity (412) and located on a side surface of the reflecting plate (45), and the stop plate (46) is closer to the third post-treatment carrier (31) than the reflecting plate (45).

Description

Exhaust post-treatment package

This application claims the priority of a Chinese patent application with an application date of April 23, 2020, an application number of 202010326919.5, and an invention title of "Exhaust Gas Post-treatment Packaging", the entire content of which is incorporated into this application by reference.

Technical field

The invention relates to a tail gas post-treatment package, belonging to the technical field of engine tail gas post-treatment.

Background technique

Studies have shown that the uniformity of ammonia distribution in the exhaust gas aftertreatment system (such as selective catalytic reduction system, SCR system) pipeline has an important impact on the overall performance and durability of the system. If the ammonia is not uniformly distributed, it will cause too much ammonia in a local area and easily cause ammonia leakage, while in other areas where ammonia is thin, the conversion efficiency of nitrogen oxides (NOx) will be too low. The uneven distribution of ammonia over a long period of time will cause uneven catalyst aging, thereby affecting the overall performance of the catalyst. In addition, the uneven distribution of urea droplets will cause the temperature of the local pipe wall or the mixing structure to be too low, forming crystals, and in severe cases, it will block the exhaust pipe and cause the engine's power performance to decrease.

Summary of the invention

The purpose of the present invention is to provide a tail gas post-treatment package with a relatively uniform airflow distribution.

In order to achieve the above objective, the present invention adopts the following technical solution: an exhaust gas after-treatment package, which includes a first housing, a first post-processing carrier packaged in the first housing, a second housing, and A second post-processing carrier in the second housing and located downstream of the first post-processing carrier, a third housing, and a second post-processing carrier packaged in the third housing and located downstream of the second post-processing carrier A third post-processing carrier and a mixing assembly connecting the second housing and the third housing; the mixing assembly includes a fourth housing, a mixing tube in the fourth housing, and a mixing tube And a reflective plate located at the lower end of the mixing tube and spaced apart from the mixing tube, the fourth housing is provided with a first cavity communicating with the second post-processing carrier, and The second cavity connected to the third post-processing carrier and the partition separating the first cavity from the second cavity, and the mixing tube includes an exposed in the first cavity The plurality of swirling fins and the plurality of perforations exposed in the second cavity; the mixing assembly further includes a baffle located in the second cavity and on the side of the reflecting plate, wherein the baffle It is closer to the third post-processing carrier than the reflecting plate.

Compared with the prior art, the present invention can have a positive effect on the uniform distribution of the air flow by providing a baffle, thereby facilitating the uniform distribution of the air flow on the inlet end surface of the third post-processing carrier.

Description of the drawings

Fig. 1 is a three-dimensional schematic diagram of an exhaust gas post-treatment package of the present invention.

Fig. 2 is a perspective schematic view of Fig. 1 from another angle.

Fig. 3 is a front view of Fig. 1.

Fig. 4 is a bottom view of Fig. 1.

Fig. 5 is a plan view of Fig. 1.

Fig. 6 is a right side view of Fig. 1.

Fig. 7 is a left side view of Fig. 1.

Fig. 8 is a partially exploded perspective view of Fig. 2.

Fig. 9 is a partially exploded perspective view of the mixing assembly in Fig. 8.

Fig. 10 is a perspective schematic view of a part of the mixing assembly in Fig. 9.

Fig. 11 is a perspective schematic view of Fig. 10 from another angle, in which the baffle is separated.

Fig. 12 is a further perspective exploded view of Fig. 11.

Figure 13 is a perspective schematic view of the bracket assembly.

Fig. 14 is an exploded perspective view of Fig. 13.

Detailed ways

1 to 14, the present invention discloses an exhaust gas after-treatment package 100, which includes a first housing 1, a first post-processing carrier 11 encapsulated in the first housing 1, a second Housing 2, a second post-processing carrier 21 encapsulated in the second housing 2 and located downstream of the first post-processing carrier 11, a third housing 3, encapsulated in the third housing 3 And a third post-processing carrier 31 located downstream of the second post-processing carrier 21, a mixing assembly 4 connecting the second housing 2 and the third housing 3, and the first post-processing carrier 11 The air inlet housing 5 connected to each other, the air inlet pipe 6 mounted on the air inlet housing 5, the air outlet housing 7 communicated with the third post-processing carrier 31, and the air inlet housing 7 are fixed on the air inlet housing 5 on the bracket assembly 8.

In the illustrated embodiment of the present invention, the exhaust gas post-treatment package 100 is substantially U-shaped. The first after-treatment carrier 11 is a diesel oxidation catalyst (DOC), the second after-treatment carrier 21 is a diesel particulate filter (DPF), and the third after-treatment carrier 31 is a selective catalytic reduction agent (SCR). ), wherein the first housing 1 and the second housing 2 are arranged in axial alignment, and the third housing 3 is parallel to the first housing 1 and the second housing 2; The intake pipe 6 extends in the direction of the mixing assembly 4 so that the intake pipe 6 does not protrude from the exhaust gas aftertreatment package 100 in the width direction, thereby reducing the width of the exhaust gas aftertreatment package 100.

The mixing assembly 4 includes a fourth housing 41, a mixing pipe 42 located in the fourth housing 41, a porous pipe 43 located in the mixing pipe 42, and a porous plate 44 located at the bottom of the mixing pipe 42 , A reflecting plate 45 located at the lower end of the mixing pipe 42 and spaced apart from the mixing pipe 42, and a baffle 46 located in the second cavity 412 and located on the side of the reflecting plate 45. In the illustrated embodiment of the present invention, the fourth housing 41 is a double-layer housing. The fourth housing 41 is provided with a first cavity 411 communicating with the second post-processing carrier 21, a second cavity 412 communicating with the third post-processing carrier 31, and connecting the first A partition 413 separates the cavity 411 from the second cavity 412. The mixing tube 42 includes a plurality of swirl fins 421 exposed in the first cavity 411 and a plurality of perforations 422 exposed in the second cavity 412. The top of the fourth housing 41 is provided with a nozzle mounting seat 414 for mounting a urea nozzle (not shown). The urea nozzle is used to spray atomized urea droplets into the mixing tube 42. The porous tube 43 and the porous plate 44 facilitate further crushing of the urea into smaller particles, thereby reducing the risk of urea crystallization and improving the uniformity of ammonia.

Specifically, in the illustrated embodiment of the present invention, the reflecting plate 45 is ω-shaped; the reflecting plate 45 is obliquely arranged in the second cavity 412 to guide the airflow to the baffle 46. The reflecting plate 45 is inclined toward the third post-processing carrier 31. The baffle 46 is closer to the third post-processing carrier 31 than the reflecting plate 45 is. A first opening 461 is formed between the bottom surface of the baffle 46 and the reflecting plate 45 for a part of the airflow to pass through; the space above the top surface of the baffle 46 forms a second opening for another part of the airflow to pass through. Opening 462. The reflecting plate 45 is provided with a ridge portion 451 located in the middle, and the top surface of the baffle 46 is higher than the ridge portion 451. In the illustrated embodiment of the present invention, there are two first openings 461 located on both sides of the spine portion 451, and a plurality of back pressure adjusting holes 452 are respectively provided at both ends of the reflecting plate 45.

The bracket assembly 8 includes a mounting portion 81, a first support rod 82 and a second support rod 83 fixed on the mounting portion 81, and a first strap assembly 84 and a second strap assembly 85. Specifically, the mounting portion 81 is provided with a plurality of mounting holes 811 for mounting the exhaust after-treatment package 100 to the vehicle body. The mounting hole 811 may be a threaded hole. The mounting portion 81 further includes a first sleeve portion 812 and a second sleeve portion 813. The first support rod 82 is inserted and fixed in the first sleeve part 812, and the second support rod 83 is inserted and fixed in the second sleeve part 813. The bracket assembly 8 also includes two first mounting seats 821 spaced apart and fixed on the first support rod 82 and two second mounting seats 831 spaced apart and fixed on the second support rod 83 . The first strap assembly 84 is fixed to one of the first mounting seat 821 and one of the second mounting seats 831, and the second strap assembly 85 is fixed to the other of the first mounting seat 821 and the other. One of the second mounting bases 831. The first strap assembly 84 includes a first strap 841 and a second strap 842, wherein the first strap 841 is fixed on the first housing 1, and the second strap 842 is fixed on the The third shell 3; the second strap assembly 85 includes a third strap 851 and a fourth strap 852, wherein the third strap 851 is fixed on the second shell 2, the The fourth strap 852 is fixed on the third housing 3. With this arrangement, by providing the bracket assembly 8, on the one hand, it is convenient to install the exhaust after-treatment package 100 on the vehicle body; on the other hand, by setting the first strap assembly 84 and the second strap assembly 85, the first housing 1 can be , The second housing 2 and the third housing 3 are connected as a whole, which improves the reliability of the product.

When in use, the exhaust gas of the diesel engine enters the intake housing 5 from the intake pipe 6; then, the exhaust gas sequentially passes through the first post-treatment carrier 11 and the second post-treatment carrier 21 into the first cavity 411 of the mixing assembly 4 ; Then, the tail gas spinneret 421 rotates into the mixing tube 42; the tail gas and the urea droplets are mixed in the mixing tube 42 and form a downward rotating air flow; subsequently, the air flow is divided into two under the action of the reflector 45 Set the airflow in the opposite direction of rotation (part of the airflow rotates clockwise, the other part of the airflow rotates counterclockwise), thereby increasing the mixing distance, which is beneficial to improve the evaporation, pyrolysis, and hydrolysis of the urea liquid; then, the role of the baffle 46 Part of the airflow passes through the first opening 461, and another part of the airflow passes through the second opening 462, so that the airflow can be relatively evenly distributed on the inlet end surface of the third post-processing carrier 31, which is beneficial to improve the conversion efficiency of nitrogen oxides. . Finally, the air flow from the third post-processing carrier 31 exits from the air outlet housing 7.

The above embodiments are only used to illustrate the present invention and not to limit the technical solutions described in the present invention. The understanding of this specification should be based on those skilled in the art, although this specification has already described the present invention in detail with reference to the above embodiments. Note, however, those of ordinary skill in the art should understand that those skilled in the art can still modify or equivalently replace the present invention, and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered in Within the scope of the claims of the present invention.

Claims

An exhaust gas post-processing package, which includes a first housing, a first post-processing carrier packaged in the first housing, a second housing, and packaged in the second housing and located in the first housing. A second post-processing carrier downstream of the post-processing carrier, a third housing, a third post-processing carrier packaged in the third housing and located downstream of the second post-processing carrier, and connected to the second housing Body and the third shell mixing assembly; the mixing assembly includes a fourth shell, a mixing tube in the fourth shell, a porous tube in the mixing tube, and a lower end of the mixing tube And the reflecting plate is arranged spaced apart from the mixing tube, the fourth housing is provided with a first cavity communicating with the second post-processing carrier, and a second cavity communicating with the third post-processing carrier Body and a partition separating the first cavity and the second cavity, and the mixing tube includes a number of swirling fins exposed in the first cavity and exposed in the second cavity. Several perforations in the cavity; characterized in that: the mixing assembly further includes a baffle located in the second cavity and located on the side of the reflector, wherein the baffle is closer to the reflector than the reflector Said third post-processing carrier.
The exhaust gas post-treatment package according to claim 1, wherein the reflector is ω-shaped; the reflector is obliquely arranged in the second cavity to guide the airflow to the baffle; The reflecting plate is inclined toward the third post-processing carrier.
The exhaust gas after-treatment package according to claim 2, wherein a first opening is formed between the bottom surface of the baffle and the reflecting plate for a part of the air flow to pass through; The space forms a second opening for another part of the airflow to pass through.
The exhaust gas after-treatment package according to claim 3, wherein the reflector is provided with a spine part located in the middle, and the top surface of the baffle is higher than the spine part.
The exhaust gas post-treatment package according to claim 4, wherein there are two first openings and are located on both sides of the spine portion, and two ends of the reflector are respectively provided with a plurality of back pressure adjustment holes.
The exhaust gas after-treatment package according to claim 1, wherein the first after-treatment carrier is a diesel oxidation catalyst, the second after-treatment carrier is a diesel particulate trap, and the third after-treatment carrier is A selective catalytic reduction agent, wherein the first housing and the second housing are arranged in axial alignment, and the third housing is parallel to the first housing and the second housing; the exhaust gas The after-treatment package includes an air inlet casing communicating with the first after-treatment carrier and an air inlet pipe mounted on the air inlet casing, and the air inlet pipe extends in the direction of the mixing assembly.
The exhaust gas after-treatment package according to claim 6, wherein the exhaust gas after-treatment package further comprises a bracket assembly fixed on the intake housing, the bracket assembly includes a mounting portion, and the mounting portion is provided with There are a number of mounting holes for mounting the exhaust gas after-treatment package on the vehicle body.
The exhaust gas after-treatment package according to claim 7, wherein the mounting portion is provided with a first sleeve portion and a second sleeve portion, and the bracket assembly further includes being inserted into the first sleeve portion The first support rod and the second support rod inserted in the second sleeve part.
The exhaust gas after-treatment package of claim 8, wherein the bracket assembly further comprises two first mounting seats spaced apart and fixed on the first support rod, and spaced apart and fixed on the first support rod. Two second mounting seats on the two support rods.
The exhaust gas aftertreatment package of claim 9, wherein the bracket assembly further comprises a first strap assembly fixed on one of the first mounting seat and one of the second mounting seat, and a first strap assembly fixed on The second strap assembly on the other of the first mounting seat and the other of the second mounting seat, the first strap assembly including a first strap and a second strap, wherein the first strap Fixed on the first shell, the second strap is fixed on the third shell; the second strap assembly includes a third strap and a fourth strap, wherein the third strap The strap is fixed on the second housing, and the fourth strap is fixed on the third housing.