CN212226097U

CN212226097U - Airflow control valve, mixer, and exhaust aftertreatment system

Info

Publication number: CN212226097U
Application number: CN202021024528.XU
Authority: CN
Inventors: 卢多维奇·盖恩特
Original assignee: Faurecia Emissions Control Technologies Development Shanghai Co Ltd
Current assignee: Faurecia Emissions Control Technologies Development Shanghai Co Ltd
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2020-12-25
Anticipated expiration: 2030-06-05

Abstract

The utility model relates to an air current control valve, blender and exhaust aftertreatment system. The airflow control valve comprises a valve base, wherein the valve base is a fixing piece; a torsion spring; the valve cover body is pivoted with the valve base through the torsion spring so as to rotate between a first position and a second position relative to the valve base; and a cover covering the torsion spring.

Description

Airflow control valve, mixer, and exhaust aftertreatment system

Technical Field

The utility model relates to an exhaust-gas treatment field especially relates to an air current control valve, blender and exhaust aftertreatment system.

Background

Engine exhaust aftertreatment systems treat hot exhaust gases produced by the engine through various upstream exhaust components to reduce exhaust pollutants. The various upstream exhaust components may include one or more of the following: pipes, filters, valves, catalysts, mufflers, etc. For example, an upstream exhaust component directs exhaust gases into a Diesel Oxidation Catalyst (DOC) having an inlet and an outlet. Downstream of the Diesel oxidation catalyst, a Diesel Particulate Filter (DPF) may be arranged. Downstream of the diesel oxidation catalyst and the optional diesel particulate filter is a Selective Catalytic Reduction (SCR) catalyst having an inlet and an outlet. The outlet passes the exhaust to a downstream exhaust component. A mixer (mixer) is positioned downstream of the outlet of the DOC or DPF, upstream of the inlet of the SCR catalyst. Within the mixer, the exhaust gas produces a swirling or rotational motion. A doser (doser) is used to inject a reductant, such as an aqueous urea solution, into the exhaust stream upstream of the SCR catalyst such that the mixer can thoroughly mix the urea and exhaust together for discharge into the SCR catalyst for reduction to produce nitrogen and water to reduce the nitrogen oxide emissions of the engine.

In the mixer of the prior art, the air flow port includes an air inlet and an air outlet, which are generally disposed on an upstream partition and a downstream partition of the mixer, respectively, and the flow areas of the air inlet and the air outlet are fixed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an air current control valve.

It is another object of the present invention to provide a mixer.

It is a further object of the present invention to provide an exhaust aftertreatment system.

According to one aspect of the utility model, the air flow control valve comprises a valve base, wherein the valve base is a fixing piece; a torsion spring; the valve cover body is pivoted with the valve base through the torsion spring so as to rotate between a first position and a second position relative to the valve base; and a cover covering the torsion spring.

In one or more embodiments of the airflow control valve, two ends of the torsion spring are connected to the valve base, and the cover and the valve cover body jointly define a first space, so that the torsion spring is covered in the first space.

In one or more embodiments of the airflow control valve, the torsion spring is a coil spring.

In one or more embodiments of the airflow control valve, the cover includes an arc-shaped portion that defines the first space together with the valve cover body.

In one or more embodiments of the airflow control valve, the cover further includes an extension portion extending from an arc-shaped end of the arc-shaped portion along a surface of the valve cover body and fixedly connected to the surface of the valve cover body, and an arc-shaped other end of the arc-shaped portion is fixedly connected to the valve cover body.

In one or more embodiments of the airflow control valve, the valve base has an airflow passage, and the valve cover body rotates between a first position and a second position with respect to an inlet portion or an outlet portion of the airflow passage to change a flow area of the inlet portion or the outlet portion of the airflow passage.

According to another aspect of the present invention, there is provided a mixer, comprising an air flow port, the air flow port being provided with an air flow control valve for controlling an air flow rate of the air flow port, wherein the air flow control valve is any one of the above air flow control valves

In one or more embodiments of the mixer, the mixer further comprises an injection port such that the reducing agent solution enters the mixer from the injection port; the torsion spring of the airflow control valve is located at an end of the airflow control valve away from the injection port.

According to another aspect of the present invention, an exhaust gas aftertreatment system includes the mixer described above, and a doser for injecting a reducing agent solution into the mixer.

In one or more embodiments of the exhaust aftertreatment system, the reductant solution is a urea solution.

The utility model discloses an advance effect includes but not limited to:

1. the flow area of the air inlet and/or the air outlet of the mixer is variable through the arrangement of the airflow control valve, so that the requirement of large exhaust flow on the large flow area of the air inlet and/or the air outlet under the large-load working condition of the engine can be met, and the back pressure is prevented from increasing under the large working condition; meanwhile, the flow area can be adaptively reduced under a small working condition so as to meet the requirement of constructing airflow vortex at other parts of the mixer;

2. the air flow control valve is provided with the cover, so that the reducing agent solution sprayed in the mixer, such as urea solution, can be prevented from crystallizing on the torsion spring, the torsion spring is corroded to fail, or the valve cover body cannot be opened at a proper angle or closed in time due to the fact that urea crystals block the torsion of the spring.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, it being noted that the drawings are given by way of example only and are not drawn to scale, and should not be taken as limiting the scope of the invention, which is actually claimed, wherein:

FIG. 1 is an internal block diagram of an exhaust system with a valve cover of an airflow control valve in a first position, according to an embodiment.

FIG. 2 is an internal block diagram of an exhaust system with a valve cover of an airflow control valve in a second position, according to an embodiment.

FIG. 3 is a block diagram of an embodiment of an airflow control valve with a valve cover in a second position.

FIG. 4 is a block diagram of an embodiment of an airflow control valve with a valve cover in a first position.

Fig. 5 is a structural view according to a rear view of fig. 4.

Fig. 6 is a structure view with a cover separated according to the airflow control valve of fig. 4.

Fig. 7 is a photographic image of urea deposition on the coil spring without the cover of the airflow control valve.

Reference numerals:

10-mixer

101-upstream baffle

102-air intake

103-ejection orifice

20-quantitative feeder

30-reducing agent solution

31-urea crystals

1-air flow control valve

11-valve base

110-gas flow channel

12-torsion spring

13-valve cover body

14-cover

141-arc part

142-extension part

40-first space

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the present disclosure, but these are merely examples and are not intended to limit the scope of the present invention.

In addition, the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and if not stated otherwise, the terms do not have special meanings, and therefore, the scope of the present invention should not be construed as being limited. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one or more embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

In the present application, "exhaust" refers to exhaust gas (exhaust) generated after combustion of an engine, and does not refer to an action or process of "gas discharge".

As shown in fig. 1 and 2, an engine exhaust aftertreatment system may include a mixer 10 and a doser 20, the doser 20 spraying a reductant solution 30, typically a urea solution, onto the mixer 10. The urea solution enters the mixer 10 from the injection port 103 of the mixer 10. The urea solution is heated and decomposed into ammonia in the mixer 10 and is fully mixed with the swirling exhaust gas to form mixed exhaust gas, and after the mixed exhaust gas flows out of the air outlet of the mixer, the exhaust gas is subjected to reduction reaction in the SCR catalyst to generate nitrogen and water so as to reduce the emission of nitrogen oxides of the engine.

Referring to fig. 1 to 6, in the mixer 10, an upstream baffle 101 of the mixer 10 is provided with an inlet 102 of the mixer, exhaust gas enters the mixer 10 from the inlet 102, and the inlet 102 is provided with an airflow control valve 1. It is understood that the air flow control valve 1 may be located at the air outlet of the downstream partition of the mixer, and is not limited to the position shown in fig. 1 and 2. As shown in fig. 3 to 6, in an embodiment, the airflow control valve 1 includes a valve base 11, a torsion spring 12, a valve cover 13 and a cover 14, the valve base 11 is a fixed member fixedly connected to the air inlet 102, and the torsion spring 12 is a coil spring (coil spring) in the drawings, but not limited thereto. The valve cover 13 is pivotally connected to the valve base 11 through the torsion spring 12 to rotate between a first position P1 and a second position P2 relative to the valve base 11, referring to fig. 2 and 3, when the valve cover 13 rotates to the second position P2, the opening degree of the airflow control valve 1 is the maximum, and when the valve cover 13 rotates to the first position P1, referring to fig. 1 and 4, the opening degree of the airflow control valve 1 is the minimum. It should be noted that fig. 1 to 4 are only examples, and specific rotation angles of the valve cover body 13 at the first position P1 and the second position P2 should not be limited to the specific angles shown in the drawings. In the embodiment shown in fig. 1 to 6, the rotation of the valve cover body 13 is to push the exhaust air flow entering from the air inlet 102, that is, when the engine load is small and the exhaust air flow is small, the opening degree of the air flow control valve 1 is small (note that the exhaust air flow needs to reach a critical value to push the rotation of the valve cover body 13 to open the air flow control valve 1, if the exhaust air flow is smaller than the critical value, the air flow control valve 1 is in a closed state), and when the engine load is large and the exhaust air flow is large, the opening degree of the air flow control valve 1 is large. Referring to fig. 1 to 6, the cover 14 covers the torsion spring 12. The air flow control valve 1 arranged on the mixer 10 has the advantages that the flow area of the air inlet and/or the air outlet of the mixer 10 can be changed, so that the openings of the air inlet and/or the air outlet of the upstream partition plate and/or the downstream partition plate can be increased, the requirement of large exhaust flow on the large flow area of the air inlet and/or the air outlet under the large-load working condition of an engine is met, and the back pressure increase caused by the arrangement of the mixer under the large-load working condition is prevented; meanwhile, the flow area can be adaptively reduced under a small working condition so as to be matched with the requirement of constructing airflow vortex at other parts of the mixer and fully mix exhaust gas and urea solution. In particular, as shown in fig. 7, the inventor found in practice that if the airflow control valve 1 does not have the cover 14, the torsion spring 12 accumulates a large amount of urea crystals 31 after the mixer 1 operates for a certain period of time, which leads to the torsion spring being out of order, difficult to rotate and increasing the exhaust back pressure. The provision of the cover 14 thus ensures a stable and reliable operation of the air flow control valve 1. Referring to fig. 1 and 2, the torsion spring 12 is located at the end of the airflow control valve 1 away from the injection port 103, so that the torsion spring 12 is prevented from being affected by the urea solution entering the mixer 10 from the injection port 103 as much as possible, and urea crystals in the torsion spring 12 are reduced.

With continued reference to fig. 1-6, in some embodiments, the airflow control valve 1 may be specifically configured such that the two ends of the torsion spring 12 are connected to the valve base 11, the cover 14 and the valve cover 13 together define a first space 40, and the torsion spring 12 is covered in the first space 40. The beneficial effects of such an arrangement can be combined with those shown in fig. 1 and 2, and the torsion spring 12 can be covered at different rotation angle positions of the valve cover 13, so as to further reduce the occurrence of urea crystals in the torsion spring 12.

With continued reference to fig. 1-6, in one or more embodiments, the particular structure of the cover 14 may include an arcuate portion 141, the arcuate portion 141 and the body of the valve cover cooperatively defining the first space 40. The arc-shaped portion 141 has the advantages that the arc-shaped portion 141 is beneficial to airflow movement in the mixer 10, the cover 14 can be prevented from influencing airflow movement and mixing of exhaust gas and urea solution as much as possible, meanwhile, the structure of the arc-shaped portion 141 is good in reliability, and the risk of thermal fatigue failure in an exhaust environment with high temperature can be reduced.

Referring to fig. 3 to 6, in an embodiment, the specific structure of the cover 14 may further include an extension portion 142, the extension portion 142 extends from one end of the arc-shaped portion 141 along the surface of the valve cover body 13 and is fixedly connected with the surface of the valve cover body 13, and the other end of the arc-shaped portion 141 is fixedly connected with the valve cover body 13. This makes it possible to more stably fix the cover cap 14 to the valve cover body 13, so that the cover cap 14 remains stably fixed to the valve cover body 13 during the impact of the movement of the air flow and the frequent rotation and opening and closing of the valve cover body 13. Also, the cover cap 14 is stably fixed to the valve cover body 13, so that the cover cap 14 stably and consistently provides protection against the urea spray to the torsion spring 12 regardless of the opening angle of the valve cover body 13. It will be understood by those skilled in the art that although the above embodiments describe the head cover 14 and the valve cover body 13 as two separately formed parts, this should not be taken as a limitation, for example, without excluding the case where both the head cover 14 and the valve cover body 13 are integrally formed as a single integral part.

With continued reference to fig. 1-6, in one embodiment, the specific structure of the valve base 11 may include the valve base 11 having an air flow passage 110, the air flow passage 110 being embedded in the air inlet 102 of the mixer, and the inlet or outlet portion of the air flow passage 110 being rotated between the first position P1 to the second position P2 by the valve cover 13 to change the flow area of the inlet or outlet portion of the air flow passage 110. The provision of the air flow passages 110 has the advantage that the exhaust air entering and/or exiting from the air flow ports of the mixer 10 can be directed in a flow-directing motion to optimise the air flow movement within the mixer.

In view of the above, the benefits of using the airflow control valve, mixer, and exhaust aftertreatment system described in the above embodiments include, but are not limited to,

Although the present invention has been described with reference to the above embodiments, it is not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention, all without departing from the content of the technical solution of the present invention, fall within the scope of protection defined by the claims of the present invention.

Claims

1. An airflow control valve for a mixer of an exhaust system, comprising

The valve base is a fixing piece;

a torsion spring;

the valve cover body is pivoted with the valve base through the torsion spring so as to rotate between a first position and a second position relative to the valve base; and

a cover covering the torsion spring.

2. The airflow control valve as defined in claim 1, wherein said torsion spring is connected at both ends thereof to said valve base, and said cover and said valve cover body together define a first space for housing said torsion spring therein.

3. The airflow control valve of claim 2 wherein said torsion spring is a coil spring.

4. The airflow control valve of claim 3 wherein said cover cap includes an arcuate portion that cooperates with said valve cover body to define said first space.

5. The airflow control valve according to claim 4, wherein the cover further includes an extension portion that extends from an arcuate one end of the arcuate portion along and is fixedly coupled to a surface of the valve cover body, and an arcuate other end of the arcuate portion is fixedly coupled to the valve cover body.

6. The airflow control valve of claim 1 wherein the valve base has an airflow passage and the valve cover rotates between a first position to a second position relative to the inlet or outlet of the airflow passage to vary the flow area of the inlet or outlet of the airflow passage.

7. A mixer, comprising a gas flow port provided with a gas flow control valve to control a gas flow rate of the gas flow port, wherein the gas flow control valve is the gas flow control valve according to any one of claims 1 to 6.

8. The mixer of claim 7, further comprising an injection port such that reductant solution enters the mixer from the injection port; the torsion spring of the airflow control valve is located at an end of the airflow control valve away from the injection port.

9. An exhaust gas aftertreatment system comprising a mixer according to claim 7 or 8 and a doser for injecting a reductant solution into the mixer.

10. The exhaust aftertreatment system of claim 9, wherein the reductant solution is a urea solution.