Guide baffle, oxidation catalyst and vehicle

Abstract

The present invention discloses a guide baffle, an oxidation catalyst and a vehicle, wherein the guide baffle is suitable for being installed at the inlet end of the oxidation catalyst and comprises: a plate body, wherein the plate body is gradually inclined from the periphery to the center in the direction of air flow, and the plate body is provided with a plurality of vents, wherein at least some of the plurality of vents are located at different radial positions of the plate body. The guide baffle of the present invention can effectively improve the uniformity of air flow, help improve the exhaust gas conversion efficiency in the oxidation catalyst, and has a simple structure and occupies a small space.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle exhaust gas treatment, and in particular, relates to a guide baffle, an oxidation catalyst having the guide baffle, and a vehicle having the oxidation catalyst. Background Art

[0002] With the continuous upgrading of automobile emission regulations, diesel engines must rely on a combination of in-engine purification and external purification technologies to meet more stringent regulatory requirements. Diesel engine external purification technology is post-treatment technology, which mainly includes: oxidation catalyst (DOC), particulate filter (DPF), selective catalytic reducer (SCR), etc. After the in-engine purification, the exhaust gas enters the DOC to oxidize pollutants such as CH and CO, and then filters and captures particles through the DPF, and finally reduces NOX by the SCR. In the process of realizing the present invention, the inventors found that in the related technology, the exhaust gas has poor uniformity after entering the DOC, resulting in inconsistent reaction efficiency in various regions of the DOC, which seriously affects the exhaust gas conversion efficiency, and there is room for improvement. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a guide baffle, which can effectively improve the uniformity of airflow passing through.

[0004] According to the guide baffle of an embodiment of the present invention, the guide baffle is suitable for being installed at the inlet end of the oxidation catalyst, and comprises: a plate body, the plate body gradually inclines toward the direction of air flow from the periphery to the center, and the plate body is provided with a plurality of air holes, at least some of the plurality of air holes are located at different radial positions of the plate body.

[0005] The guide baffle according to the embodiment of the present invention can effectively improve the uniformity of airflow passing therethrough, help improve the exhaust gas conversion efficiency in the oxidation catalyst, and has a simple structure and occupies a small space.

[0006] According to a guide baffle of one embodiment of the present invention, the vent holes include the 1st to nth circles arranged in sequence from the inside to the outside, wherein the kth circle includes a plurality of the vent holes distributed and spaced apart along the circumferential direction, and the vent holes of the kth circle surround the vent holes of the k-1th circle, k and n are both positive integers, and n≥2, k=2, ..., n.

[0007] According to a guide baffle of one embodiment of the present invention, each of the air holes in the i-th circle has the same shape and the same flow area, i is a positive integer, i=1, ..., n, the flow area of ​​each of the air holes in the k-th circle is not less than the flow area of ​​each of the air holes in the k-1-th circle, and the number of the air holes in the k-th circle is greater than the number of the air holes in the k-1-th circle.

[0008] According to a guide baffle of one embodiment of the present invention, the flow area of ​​each of the air holes in the first circle is greater than the flow area of ​​each of the air holes in the second circle, the flow areas of each of the air holes in the second to jth circles are the same, the flow area of ​​each of the air holes in the jth circle is greater than the flow area of ​​each of the air holes in the j+1th circle, the flow areas of each of the air holes in the j+1th to nth circles are the same, j is a positive integer, j-2≥1, nj-1≥1.

[0009] According to the guide baffle of one embodiment of the present invention, the ventilation holes in the kth circle and the ventilation holes in the k-1th circle are staggered in radial distribution.

[0010] According to the guide baffle of an embodiment of the present invention, the vent hole is circular.

[0011] According to the guide baffle of one embodiment of the present invention, the outer periphery of the plate body has an annular flange, and the flange is used to press against the end surface of the catalytic carrier of the oxidation catalyst.

[0012] According to the guide baffle of one embodiment of the present invention, a plurality of connecting plates extending radially outward are provided at the outer periphery of the flange, and the connecting plates are suitable for being welded to the housing or the catalytic carrier of the oxidation catalyst.

[0013] The present invention also proposes an oxidation catalyst, comprising a guide baffle as described in any one of the above, wherein the guide baffle is installed at the front end of the catalyst carrier of the oxidation catalyst, and the center of the plate body protrudes toward the direction close to the catalyst carrier.

[0014] The advantages of the oxidation catalyst and the above-mentioned guide baffle over the prior art are the same, which will not be described in detail here.

[0015] The present invention also provides a vehicle, comprising any one of the oxidation catalysts described above.

[0016] The advantages of the vehicle and the above-mentioned oxidation catalyst over the prior art are the same and will not be described in detail here.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a schematic diagram of the structure of a guide baffle along the axial direction according to an embodiment of the present invention;

[0020] Figure 2 4 is a side view of a guide baffle according to an embodiment of the present invention.

[0021] Reference numerals:

[0022] The guide baffle 100,

[0023] The plate body 10 , the vent hole 11 , the flange 20 , and the connecting plate 30 . DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The exhaust gas after-treatment system according to an embodiment of the present invention is described below. The exhaust gas after-treatment system includes: an oxidation catalyst, a particulate trap, and some modules of a selective catalytic reducer.

[0028] Among them, in the exhaust after-treatment system of the National VI system, the oxidation catalyst, the particulate filter, and the selective catalytic reducer are arranged sequentially along the flow direction of the exhaust gas, and the guide baffle 100 is installed at the inlet end of the oxidation catalyst; in the exhaust after-treatment system of the National V system, the oxidation catalyst and the selective catalytic reducer are arranged sequentially along the flow direction of the exhaust gas or the oxidation catalyst and the particulate filter are arranged sequentially along the flow direction of the exhaust gas, and the guide baffle 100 is installed at the inlet end of the oxidation catalyst.

[0029] The exhaust gas after-treatment system of the embodiment of the present invention can be used for diesel engines. For example, for the exhaust gas after-treatment system of the National VI system, after the exhaust gas discharged by the engine passes through the guide baffle 100, the uniformity of the airflow at various locations in the radial direction is greatly improved, including the flow velocity and component uniformity of the airflow at various locations in the radial direction. After the airflow passes through the guide baffle 100, it enters the catalytic carrier of the oxidation catalyst. The pollutants such as CH and CO in the exhaust gas undergo oxidation reaction in the catalytic carrier of the oxidation catalyst. Due to the mixing effect of the guide baffle 100, the reaction at various locations in the catalytic carrier of the oxidation catalyst is uniform, and the catalytic efficiency is high. The exhaust gas is then filtered and captured by the particulate collector, and finally the NOX is reduced by the selective catalytic reducer.

[0030] The oxidation catalyst of the embodiment of the present invention includes a guide baffle 100, which is installed at the front end of the catalyst carrier of the oxidation catalyst, and the center of the plate body 10 of the guide baffle 100 protrudes toward the direction close to the catalyst carrier. The guide baffle 100 can play a role in mixing flow, so that the uniformity of the airflow at various locations in the radial direction is greatly improved, including the uniformity of the flow velocity and components of the airflow at various locations in the radial direction. The airflow enters the catalyst carrier after passing through the guide baffle 100.

[0031] Reference below Figure 1-Figure 2 The guide baffle 100 according to the embodiment of the present invention is described.

[0032] like Figure 1-Figure 2 As shown, a guide baffle 100 according to an embodiment of the present invention is suitable for being installed at the inlet end of an oxidation catalyst, and the guide baffle 100 comprises: a plate body 10, the plate body 10 gradually inclines toward the airflow direction from the periphery to the center, and the plate body 10 is provided with a plurality of vents 11, at least some of the plurality of vents 11 are located at different radial positions of the plate body 10.

[0033] It can be understood that the plate body 10 is a recessed structure in the flow direction of the airflow, and the airflow located radially outward on the gas flow section first enters the oxidation catalyst through the radially outward vents 11. The plate body 10 of this structural form can balance the flow velocity of the gas at various locations in the radial direction and the components of the gas at various locations in the radial direction, so that the exhaust gas flowing into each area of ​​the oxidation catalyst is more balanced and the conversion efficiency is high, and the guide baffle 100 is directly installed at the inlet end of the oxidation catalyst without occupying additional space.

[0034] The guide baffle 100 according to the embodiment of the present invention can effectively improve the uniformity of airflow passing therethrough, help improve the exhaust gas conversion efficiency in the oxidation catalyst, and has a simple structure and occupies a small space.

[0035] The oxidation catalyst according to the embodiment of the present invention has high gas flow uniformity, high exhaust gas conversion efficiency, simple structure, and is easy to assemble.

[0036] In some embodiments, Figure 1 As shown, the vent holes 11 include the 1st to nth circles, wherein the kth circle includes a plurality of vent holes 11 spaced apart and distributed along the circumferential direction, and the vent holes 11 of the kth circle surround the vent holes 11 of the k-1th circle, k and n are both positive integers, and n≥2, k=2, ..., n. In other words, there are a plurality of vent holes 11 of the kth circle, and the plurality of vent holes 11 of the kth circle surround the vent holes 11 of the k-1th circle, for example, the centers of the plurality of vent holes 11 of the kth circle can be located on the circumference of the same circle.

[0037] Each vent hole 11 in the i-th circle has the same shape and the same flow area, i is a positive integer, i=1, ..., n, that is, the shapes of the vent holes 11 in the same circle are all the same, for example, they can all be circular and have the same diameter.

[0038] The flow area of ​​each vent hole 11 in the kth circle is not less than the flow area of ​​each vent hole 11 in the k-1th circle, and the number of vent holes 11 in the kth circle is greater than the number of vent holes 11 in the k-1th circle. In other words, the flow area of ​​the multiple vent holes 11 does not increase monotonically from the radial inside to the radial outside along the distribution position, the flow area of ​​the single vent hole 11 in the innermost circle is the largest, and the flow area of ​​the single vent hole 11 in the outermost circle is the smallest. It can be understood that the air flow velocity of the inner circle is relatively large, and by providing the vent holes 11 of the above structure, the air flow velocity on the radial outside can be increased, thereby reducing the difference in air flow velocity between the radial inside and the radial outside.

[0039] In some embodiments, the flow area of ​​each vent hole 11 in the first circle is greater than the flow area of ​​each vent hole 11 in the second circle, the flow areas of each vent hole 11 in the second circle to the jth circle are the same, the flow area of ​​each vent hole 11 in the jth circle is greater than the flow area of ​​each vent hole 11 in the j+1th circle, and the flow areas of each vent hole 11 in the j+1th circle to the nth circle are the same, j is a positive integer, j-2≥1, nj-1≥1. In this way, the size types of the vent holes 11 can be reduced, and the molding difficulty can be reduced.

[0040] for example Figure 1In the figure, n=9, j=5, there is one vent hole 11 in the first circle, and it is a circle with a diameter of 16 mm. The second circle includes multiple vent holes 11, the flow area of ​​each vent hole 11 in the second to fifth circles is the same, and the vent holes 11 in the second to fifth circles are circles with a diameter of 8 mm. The flow area of ​​each vent hole 11 in the sixth to ninth circles is the same, and the vent holes 11 in the sixth to ninth circles are circles with a diameter of 3.5 mm.

[0041] Of course, the flow areas of the vent holes 11 between the circles may be different, that is, the flow areas of the vent holes 11 decrease monotonically from the inside to the outside in the radial distribution position.

[0042] refer to Figure 1 The vent holes 11 of the kth circle are staggered with the vent holes 11 of the k-1th circle in the radial direction. In this way, the air flow passing performance is better and the power loss of the air flow at the guide baffle 100 is less.

[0043] refer to Figure 1 The vent hole 11 may be circular, and the circular vent hole 11 has a good effect on the uniformity of the airflow. Of course, the shape of the vent hole 11 is not limited to a circle, and may also be other polygons such as a triangle and a rectangle.

[0044] like Figure 2 As shown, the plate body 10 has an arcuate cross section, or the plate body 10 may have a spherical crown cross section or other arcuate cross sections, so that the axial length of the plate body 10 is small and easy to arrange.

[0045] like Figure 1-Figure 2 As shown, the outer periphery of the plate body 10 has an annular flange 20, the normal of the flange 20 is parallel to the axis of the plate body 10, the flange 20 is used to press the end face of the catalytic carrier of the oxidation catalyst, the flange 20 can be used for axial positioning of the guide baffle 100, and the outer periphery of the flange 20 is provided with a plurality of connecting plates 30 extending radially outward, for example, three, the connecting plates 30 are suitable for being welded to the housing or the catalytic carrier of the oxidation catalyst, so that the guide baffle 100 and the catalytic carrier of the oxidation catalyst can be integrated for easy assembly.

[0046] In a specific embodiment of the present invention, the guide baffle 100 is an integrated stainless steel part, and the plate body 10 has 9 circles of vent holes 11. The vent holes 11 of the first circle are a circle with a diameter of 16 mm, and the vent holes 11 of the second circle to the ninth circle each include a plurality of vent holes 11 spaced apart along the circumferential direction, and the vent holes 11 of the second circle to the fifth circle are circles with a diameter of 8 mm, and the vent holes 11 of the sixth circle to the ninth circle are circles with a diameter of 3.5 mm. The vent holes 11 of the second circle to the ninth circle are staggered in the radial direction. The guide baffle 100 is welded to the intake end of the oxidation catalyst. The inventor found through experimental comparison that when the gas flow rate is 578 kg / h, after the guide baffle 100 is set, the gas flow uniformity of the oxidation catalyst is 0.945, which is more than 5% higher than 0.898 without this structure.

[0047] The present invention also discloses a vehicle. The vehicle of the embodiment of the present invention has an oxidation catalyst of any of the above embodiments. The vehicle of the embodiment of the present invention may be a diesel vehicle. The vehicle of the embodiment of the present invention has low emission pollution.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0049] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A guide baffle (100), characterized in that: The guide baffle (100) is suitable for being installed at the inlet end of the oxidation catalyst, and comprises: a plate body (10), the plate body (10) gradually tilting towards the airflow direction from the periphery to the center, and the plate body (10) is provided with a plurality of vent holes (11), at least some of the plurality of vent holes (11) are located at different radial positions of the plate body (10); The vent holes (11) include a 1st circle to an nth circle arranged in sequence from the inside to the outside, wherein the kth circle includes a plurality of the vent holes (11) spaced apart and distributed along the circumferential direction, and the vent holes (11) of the kth circle surround the vent holes (11) of the k-1th circle, k and n are both positive integers, and n≥2, k=2, ..., n; Each of the vent holes (11) in the i-th circle has the same shape and the same flow area, i is a positive integer, i=1, ..., n, and the number of the vent holes (11) in the k-th circle is greater than the number of the vent holes (11) in the k-1-th circle; The flow area of ​​each of the vent holes (11) in the first circle is greater than the flow area of ​​each of the vent holes (11) in the second circle, the flow areas of each of the vent holes (11) in the second circle to the jth circle are the same, the flow area of ​​each of the vent holes (11) in the jth circle is greater than the flow area of ​​each of the vent holes (11) in the j+1th circle, and the flow areas of each of the vent holes (11) in the j+1th circle to the nth circle are the same, j is a positive integer, j-2≥1, nj-1≥1; The ventilation holes (11) of the kth circle and the ventilation holes (11) of the k-1th circle are staggered in radial distribution; The outer periphery of the plate body (10) has an annular flange (20), and the flange (20) is used to press against the end surface of the catalytic carrier of the oxidation catalyst; The outer periphery of the flange (20) is provided with a plurality of connecting plates (30) extending radially outward, and the connecting plates (30) are suitable for being welded to the housing or the catalytic carrier of the oxidation catalyst.

2. The guide baffle (100) according to claim 1, characterized in that: The vent hole (11) is circular.

3. An oxidation catalyst, characterized in that: It comprises a guide baffle (100) as claimed in any one of claims 1 to 2, wherein the guide baffle (100) is installed at the front end of the catalyst carrier of the oxidation catalyst, and the center of the plate body (10) protrudes towards the direction close to the catalyst carrier.

4. A vehicle, characterized in that: Comprising the oxidation catalyst as claimed in claim 3.

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