CN213743606U

CN213743606U - Engine exhaust treatment system

Info

Publication number: CN213743606U
Application number: CN202021920597.9U
Authority: CN
Inventors: 杨广拓; 闫聪; 王笛; 侯文媛
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-09-04
Filing date: 2020-09-04
Publication date: 2021-07-20
Anticipated expiration: 2030-09-04

Abstract

The application discloses an engine exhaust treatment system, which comprises a first exhaust treatment unit; a second exhaust treatment unit in fluid communication with the first exhaust treatment unit via a first conduit; a third exhaust treatment unit in fluid communication with the third exhaust treatment unit via a second conduit, the second exhaust treatment unit comprising a housing including an open end in fluid communication with the first conduit and a closed end opposite the open end along an axial direction, the housing further including a port in fluid communication with the second conduit, the port being in fluid communication with the closed end via a channel provided on the housing, the port being located between the open end and the closed end.

Description

Engine exhaust treatment system

Technical Field

The present application relates to engine exhaust treatment systems, particularly diesel engine exhaust treatment systems.

Background

Currently, engine exhaust treatment systems employ a variety of technical routes to meet increasingly stringent automotive emissions standards. Taking a diesel vehicle as an example, an engine exhaust treatment system of the diesel vehicle generally includes, from upstream to downstream, a diesel catalytic oxidizer (DOC), a Selective Diesel Particulate Filter (SDPF), and a Selective Catalytic Reducer (SCR).

The limited space of the layout of the chassis of the motor vehicle is limited, so that a plurality of constituent units of the exhaust gas treatment system must be arranged in a narrow chassis space, which inevitably results in that connecting pipelines between the units cannot be coordinated, and causes that individual pipelines are too long, so that the temperature of the gas to be treated is reduced too fast when the gas flows between different units, thereby affecting the final exhaust gas treatment efficiency.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present application aims to solve how to rationally arrange the constituent units of an engine exhaust gas treatment system so that the temperature of the gas to be treated is not excessively lowered when switching between the respective units.

According to one aspect of the present application, an engine exhaust treatment system is disclosed, comprising:

a first exhaust gas treatment unit;

a second exhaust treatment unit in fluid communication with the first exhaust treatment unit via a first conduit;

a third waste gas treatment unit in fluid communication with the second waste gas treatment unit via a second conduit,

the second exhaust treatment unit includes a housing including an open end in fluid communication with the first duct and a closed end opposite the open end in an axial direction, the housing further including a port in fluid communication with the second duct, the port being in fluid communication with the closed end via a channel provided on the housing, the port being located axially between the open end and the closed end.

Optionally, in a second exhaust treatment unit, the flow direction of the treated exhaust from the open end to the closed end of the housing is opposite to the flow direction thereof from the closed end to the port.

Optionally, the port is axially closer to the open end than the closed end.

Optionally, at least one wall portion is provided on the housing, via which the channel is in direct fluid communication with the closed end and is isolated from the open end.

Optionally, the third exhaust treatment unit has an inlet end connected to the second conduit, the inlet end of the third exhaust treatment unit being closer to the open end of the second exhaust treatment unit than the port of the second exhaust treatment unit.

Optionally, the housing is cylindrical, and the closed end of the housing is formed by an end cap secured to an open end of the cylindrical.

Optionally, the end cap comprises a section arranged on an outer wall surface of the housing to define the channel between the outer wall surface of the housing and the section, the port being formed in the section.

Optionally, the section projects at least partially radially into the end cap.

Optionally, the end cap comprises a section arranged on an inner wall surface of the housing to define the channel between the inner wall surface of the housing and the section.

Optionally, the engine is a diesel engine, the first exhaust gas treatment unit is a diesel catalytic oxidizer, the second exhaust gas treatment unit is a selective diesel particulate filter, and the third exhaust gas treatment unit is a selective catalytic reducer.

By adopting the technical means, the length of the pipeline exposed in the air between the waste gas treatment units can be correspondingly shortened under the condition that the space of the chassis of the motor vehicle is limited, so that the final treatment effect is prevented from being influenced due to the fact that the temperature of waste gas to be treated is reduced too fast.

Drawings

The principles and aspects of the present application will be more fully understood from the following detailed description, taken in conjunction with the accompanying drawings. It is noted that the drawings may not be to scale for clarity of illustration and will not detract from the understanding of the present application. In the drawings:

FIG. 1 is a partial cross-sectional view schematically illustrating an engine exhaust treatment system according to the prior art;

FIG. 2 is a partial cross-sectional view schematically illustrating an engine exhaust treatment system according to an embodiment of the present application.

Detailed Description

In the various figures of the present application, features that are structurally identical or functionally similar are denoted by the same reference numerals.

FIG. 1 schematically illustrates a prior art engine exhaust treatment system 100. For example, the engine referred to herein may be a diesel engine. Accordingly, the system 100 may be considered a diesel engine exhaust treatment system. The diesel engine exhaust treatment system 100 generally forms a portion of an exhaust pipe of a diesel vehicle. The diesel engine exhaust treatment system 100 basically includes, as constituent units, a diesel catalytic oxidizer 110, a selective diesel particulate filter 120, and a selective catalytic reducer 130 from upstream to downstream, as viewed in the flow direction of engine exhaust. The constituent units are connected with each other by pipelines. As shown, a gas inlet 110A is defined from the diesel catalytic oxidizer 110, and a gas outlet 130A is defined from the selective catalytic reducer 130, so that engine exhaust can enter the diesel engine exhaust treatment system 100 from the gas inlet 110A in the direction indicated by the arrow, and finally be discharged from the gas outlet 130A after being sequentially treated by the respective constituent elements.

As shown in fig. 1, the diesel catalytic oxidizer 110, the selective diesel particulate filter 120, and the selective catalytic reducer 130 are not substantially linearly arranged such that the flow directions of the gas in the diesel catalytic oxidizer 110, the selective diesel particulate filter 120, and the selective catalytic reducer 130 are opposite to each other. For example, in FIG. 1, the direction of gas flow in the diesel catalytic oxidizer 110 is generally from left to right, the direction of gas flow in the selective diesel particulate filter 120 is generally from right to left, and the direction of gas flow in the selective catalytic reducer 130 is generally from left to right. This results in the outlet of the diesel catalytic oxidizer 110 being connected to the inlet of the selective diesel particulate filter 120 via conduit 140 and the outlet of the selective diesel particulate filter 120 being connected to the inlet of the selective catalytic reducer 130 via conduit 150. To ensure that the gas entering the selective diesel particulate filter 120 can be filtered to the maximum extent by the filter element inside the selective diesel particulate filter 120, the conduit 150 is connected at the leftmost end of the selective diesel particulate filter 120, resulting in an excessively long length of the conduit 150.

This design of the pipe 150 causes the gas output through the selective diesel particulate filter 120 to exchange heat with the outside through the long pipe 150, so that the exhaust gas to be treated is lowered in temperature too fast, thereby affecting the subsequent exhaust gas treatment efficiency.

In view of this, FIG. 2 schematically illustrates an engine exhaust treatment system 200 according to an embodiment of the present application. The engine exhaust treatment system 200 generally includes a first exhaust treatment unit 210, a second exhaust treatment unit 220, and a third exhaust treatment unit 230. If the engine exhaust treatment system 200 is considered a diesel engine exhaust treatment system, the first exhaust treatment unit 210 may be a diesel catalytic oxidizer, the second exhaust treatment unit 220 may be a selective diesel particulate filter, and the third exhaust treatment unit 230 may be a selective catalytic reducer. Each exhaust treatment unit includes a gas flow passage through which gas can flow. The first exhaust gas treatment unit 210 defines a gas inlet 210A, the third exhaust gas treatment unit 230 defines an air outlet 230A, and the first exhaust gas treatment unit 210 and the second exhaust gas treatment unit 220 are connected to each other via a pipe 240 and the second exhaust gas treatment unit 220 and the third exhaust gas treatment unit 230 are connected to each other via a pipe 250, such that engine exhaust gas enters the engine exhaust gas treatment system 200 via the gas inlet 210A and is then sequentially discharged via the first exhaust gas treatment unit 210, the pipe 240, the second exhaust gas treatment unit 220, the pipe 250 and the third exhaust gas treatment unit 230. As can be seen, in order to shorten the conduit 250, it is designed such that the conduit 250 is connected to the second exhaust gas treatment unit 220 close to the conduit 240 connected to the second exhaust gas treatment unit 220.

For example, the second exhaust treatment unit 220 includes a housing 221. The casing 221 is made of, for example, metal and has a substantially cylindrical or cylindrical shape, and defines a space for accommodating the exhaust gas treatment core 222 therein. Where the second exhaust treatment unit 220 is a selective diesel particulate filter, the exhaust treatment core 222 is a selective diesel particulate filter cartridge. The casing 221 includes two

open ends

221a and 221b opposite to each other in the axial direction, wherein the open end 221a communicates with the first exhaust gas treatment unit 210 via the duct 240. In this way, the exhaust gas discharged from the first exhaust gas treatment unit 210 can flow from the open end 221a to the open end 221b of the second exhaust gas treatment unit 220, thereby maximally flowing through the exhaust gas treatment core 222 for a corresponding exhaust gas treatment. The second exhaust gas treatment unit 220 further includes an end cover 223 closing the open end 221b of the housing 221, and the end cover 223 further includes a section 224 disposed on an outer wall surface of the housing 221. The end cap 223 and the section 224 may be made of the same metal as the housing 221. The end cover 223 is welded, for example, to the open end 221b of the casing 221, and the section 224 is welded to the end cover 223 and the casing 221 so that a passage 224a in fluid communication with the open end 221b is defined between the section 224 and the outer wall surface of the casing 221. That is, at least one wall portion is provided on the housing 221, through which the channel 224a is in direct fluid communication with the closed end and isolated from the open end 221 a. A port 224b is provided in section 224 for connection to conduit 250, which communicates with passage 224 a. With such a design, the port 224b can be located as close to the open end 221a of the housing 221 in the axial direction as possible, so that the length of the duct 250 can be shortened as much as possible without changing the installation position of the second exhaust gas treatment unit 220 and the third exhaust gas treatment unit 230 in the vehicle chassis space.

As shown in fig. 2, gas entering the open end 221a of the second exhaust treatment unit 220 from the first exhaust treatment unit 210 via the conduit 240 first flows (as indicated by arrow 220F) from left to right through the exhaust treatment core 222 to the open end 221 b; then, from right to left through a channel 224a (as arrow 220F) defined between the section 224 and the outer wall surface of the housing 221 to the port 224 and further to the conduit 250. The gas flows in the housing 221 in the direction opposite to the direction of the gas flowing in the passage 224a, so that the gas can be completely treated by the exhaust gas treatment core 222 in the housing 221 without a significant decrease in the temperature of the gas flowing in the passage 224a due to the passage 224a being closely attached to the outer wall surface of the housing 221.

In an alternative embodiment, the channel may also be formed by a section similar to section 224 provided on the inner wall surface of the housing 221. In this case, a port for connecting the pipe 250 may be formed in the wall of the housing 221. In an alternative embodiment, the housing 221 and the end cap 223 and/or the section 224 may be integrally formed.

Although specific embodiments of the present application have been described herein in detail, they have been presented for purposes of illustration only and are not to be construed as limiting the scope of the application. Further, it should be clear to those skilled in the art that the various embodiments described in this specification can be used in combination with each other. Various substitutions, alterations, and modifications may be conceived without departing from the spirit and scope of the present application.

Claims

1. An engine exhaust treatment system (200), comprising:

a first exhaust gas treatment unit (210);

a second exhaust treatment unit (220), the second exhaust treatment unit (220) being in fluid communication with the first exhaust treatment unit (210) via a first conduit (240);

a third effluent treatment unit (230), said second effluent treatment unit (220) being in fluid communication with said third effluent treatment unit (230) via a second conduit (250),

the second exhaust treatment unit (220) comprises a housing (221) comprising an open end (221a) in fluid communication with the first duct (240) and a closed end opposite the open end in axial direction, the housing further comprising a port (224b) in fluid communication with the second duct (250), the port (224b) being in fluid communication with the closed end via a channel (224a) provided on the housing (221), the port (224b) being located axially between the open end (221a) and the closed end.

2. The engine exhaust gas treatment system (200) of claim 1, characterized in that in a second exhaust gas treatment unit (220), the flow direction of the treated exhaust gas from the open end (221a) to the closed end of the housing (221) is opposite to its flow direction from the closed end to the port (224 b).

3. The engine exhaust gas treatment system (200) of claim 1 or 2, wherein the port (224b) is axially closer to the open end (221a) than the closed end.

4. The engine exhaust gas treatment system (200) of claim 1 or 2, characterized in that at least one wall portion is provided on the housing (221) via which the channel (224a) is in direct fluid communication with the closed end and isolated from the open end (221 a).

5. The engine exhaust gas treatment system (200) of claim 1 or 2, wherein the third exhaust gas treatment unit (230) has an inlet end connected to the second conduit (250), the inlet end of the third exhaust gas treatment unit (230) being closer to the open end (221a) of the second exhaust gas treatment unit (220) than to the port (224b) of the second exhaust gas treatment unit (220).

6. The engine exhaust treatment system (200) of claim 1 or 2, wherein the housing (221) is cylindrical, and the closed end of the housing (221) is formed by an end cap (223) secured to an open end of the cylindrical.

7. The engine exhaust gas treatment system (200) of claim 6, characterized in that the end cover (223) includes a section (224) arranged on an outer wall surface of the housing (221) to define the passage (224a) between the outer wall surface of the housing (221) and the section (224), the port (224b) being formed in the section (224).

8. The engine exhaust gas treatment system (200) of claim 7, characterized in that the section (224) protrudes at least partially radially into the end cap (223).

9. The engine exhaust gas treatment system (200) of claim 6, characterized in that the end cover (223) comprises a section arranged on an inner wall surface of the housing (221) to define the passage (224a) between the inner wall surface of the housing (221) and the section (224).

10. The engine exhaust gas treatment system (200) of claim 9, wherein the engine is a diesel engine, the first exhaust treatment unit (210) is a diesel catalytic oxidizer, the second exhaust treatment unit (220) is a selective diesel particulate filter, and the third exhaust treatment unit (230) is a selective catalytic reducer.