Exhaust treatment mixer and engine

Abstract

The present invention belongs to the technical field of automobile exhaust treatment, and discloses an exhaust treatment mixer and an engine. The exhaust treatment mixer comprises a guide pipe and a guide plate, the guide pipe comprises an intake port and an exhaust port, exhaust gas is input from the intake port and discharged from the exhaust port, a urea injection port is provided on the side wall of the guide pipe, urea is input into the interior of the guide pipe from the urea injection port; the guide plate is fixedly arranged on the inner wall of the guide pipe, the guide plate comprises a first panel, a second panel and a third panel which are sequentially connected and arranged along the direction of exhaust gas flow, the first panel and the second panel and the third panel and the second panel are arranged at an angle, and the urea injection port is located upstream of the third panel or upstream of the second panel or upstream of the first panel. The present invention reduces the resistance to the exhaust gas flow by simplifying the structure of the guide plate, and meets the use requirements of the engine.

Description

Technical Field

[0001] The invention relates to the technical field of automobile exhaust treatment, in particular to an exhaust gas treatment mixer and an engine. Background Art

[0002] The exhaust gas emitted by diesel engines mainly contains harmful gases such as nitrogen oxides, hydrocarbons, and carbon monoxide. The main function of the diesel engine's post-treatment device is to purify the harmful gases emitted. At present, diesel engines use oxidation catalyst (DOC) + particulate filter (DPF) + selective catalytic reduction (SCR) technology to treat exhaust pollutants so that exhaust emissions meet the limit requirements of the National VI Emission Regulations.

[0003] In the selective catalytic reduction technology, the exhaust gas is mostly treated by catalytic reduction through a post-treatment mixer. The exhaust gas enters the post-treatment mixer, and urea solution is sprayed in the mixer to mix the urea solution with the exhaust gas. The nitrogen oxides in the exhaust gas are catalytically reduced to ammonia before being discharged to ensure that the exhaust gas emissions meet the regulatory limit requirements.

[0004] However, the existing after-treatment mixers for diesel engines are mostly cyclone mixers, which are multi-guide plate spiral structures that guide the exhaust gas to rotate. The structure is relatively complex and has a large resistance to gas flow, resulting in increased back pressure in the entire exhaust system of the diesel engine.

[0005] Therefore, there is a need for an exhaust gas treatment mixer and an engine that can simplify the structure of the guide plate, reduce the resistance to the exhaust gas flow, and meet the use requirements of the engine. Summary of the invention

[0006] One purpose of the present invention is to provide an exhaust gas treatment mixer and an engine, simplify the structure of the guide plate, reduce the resistance to the exhaust gas flow, and meet the use requirements of the engine.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, a tail gas treatment mixer is provided, comprising:

[0009] A guide pipe, the guide pipe comprises an intake port and an exhaust port, exhaust gas is input from the intake port and discharged from the exhaust port, a urea injection port is provided on a side wall of the guide pipe, urea is input into the interior of the guide pipe from the urea injection port;

[0010] A guide plate, wherein the guide plate is fixedly arranged on the inner wall of the guide pipe, and the guide plate includes a first panel, a second panel and a third panel which are sequentially connected and arranged along the direction of exhaust gas flow, the first panel and the second panel are arranged at an angle, and the third panel and the second panel are arranged at an angle, and the urea injection port is located upstream of the third panel, upstream of the second panel, or upstream of the first panel.

[0011] As an optional technical solution, the first panel is inclined toward a side away from the urea injection port, and the third panel is inclined toward a side close to the urea injection port.

[0012] As an optional technical solution, a first notch is formed on a side of the first panel away from the second panel, and the first notch is triangular in shape.

[0013] As an optional technical solution, the first panel is further provided with a plurality of first through holes.

[0014] As an optional technical solution, a second notch is formed on a side of the third panel away from the second panel, and the second notch is triangular in shape.

[0015] As an optional technical solution, a plurality of second through holes are staggeredly arranged on the second panel.

[0016] As an optional technical solution, the guide plates are provided in plurality, and the plurality of guide plates are fixed in parallel and at intervals on the inner wall of the guide tube.

[0017] As an optional technical solution, the guide plates located in the guide pipe are arranged in sequence along the direction of exhaust gas flow, the guide plate closest to the urea injection port is also closest to the air intake port, and the guide plate farthest from the urea injection port is also farthest from the air intake port.

[0018] As an optional technical solution, the guide tube includes an inner ring layer, a middle ring layer and an outer ring layer from inside to outside, the inner ring layer and the outer ring layer are both made of stainless steel material, and the middle ring layer is made of heat insulation material.

[0019] As an optional technical solution, a urea nozzle mounting seat is welded at the urea injection port, and the urea nozzle mounting seat is made of stainless steel.

[0020] As an optional technical solution, a nitrogen oxide sensor mounting seat is welded upstream of the urea injection port, and the nitrogen oxide sensor mounting seat is made of stainless steel.

[0021] In a second aspect, an engine is provided, comprising the exhaust gas treatment mixer as described above.

[0022] The beneficial effects of the present invention are:

[0023] The invention provides an exhaust gas treatment mixer and an engine. The engine comprises the exhaust gas treatment mixer. When the engine is running, the exhaust gas passes through a first panel, a second panel and a third panel in sequence in the process of passing through a guide pipe. Since the first panel and the second panel and the third panel and the second panel are arranged at an angle, the structure of the guide plate is simplified, the resistance to the flow of the exhaust gas is extremely small, and the back pressure of the entire exhaust system is effectively reduced. The first panel, the second panel and the third panel are sequentially connected and arranged along the direction of the exhaust gas flow, and the urea injection port is located upstream of the third panel or upstream of the second panel or upstream of the first panel, that is, after the urea is injected from the urea injection port, it at least passes through the turbulence of the third panel, so that the flow rate of the urea is increased, and the exhaust gas passes through the turbulence of the first panel, the second panel and the third panel. The flow rate is accelerated, and the fast-flowing exhaust gas and the fast-flowing urea can be efficiently stirred and mixed to produce a chemical reaction, and the nitrogen oxides in the exhaust gas are decomposed, thereby meeting the use requirements of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described in detail below based on the accompanying drawings and embodiments;

[0025] Figure 1 It is a structural schematic diagram of the exhaust gas treatment mixer described in the embodiment;

[0026] Figure 2 It is a partial structural schematic diagram of the exhaust gas treatment mixer described in the embodiment;

[0027] Figure 3 This is a layout diagram when three guide plates are provided as described in the embodiment.

[0028] In the figure:

[0029] 1. Flow guide pipe; 11. Air intake port; 12. Exhaust port; 13. Urea injection port;

[0030] 2. guide plate; 21. first panel; 211. first notch; 212. first through hole; 22. second panel; 221. second through hole; 23. third panel; 231. second notch;

[0031] 3. Urea nozzle mounting seat;

[0032] 4. NOx sensor mounting seat;

[0033] 5. First flange;

[0034] 6. Second flange. DETAILED DESCRIPTION

[0035] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", etc., and the like, are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0039] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. 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.

[0040] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0041] like Figures 1 to 3 As shown, the present embodiment provides an exhaust gas treatment mixer, which includes a guide pipe 1 and a guide plate 2. The guide pipe 1 includes an intake port 11 and an exhaust port 12. The exhaust gas is input from the intake port 11 and discharged from the exhaust port 12. A urea injection port 13 is provided on the side wall of the guide pipe 1. Urea is input into the interior of the guide pipe 1 from the urea injection port 13. The guide plate 2 is fixedly arranged on the inner wall of the guide pipe 1. The guide plate 2 includes a first panel 21, a second panel 22 and a third panel 23 which are sequentially connected and arranged along the direction of exhaust gas flow. The first panel 21 and the second panel 22 and the third panel 23 and the second panel 22 are arranged at an angle. The urea injection port 13 is located upstream of the third panel 23 or upstream of the second panel 22 or upstream of the first panel 21.

[0042] Specifically, the exhaust gas treatment mixer of this embodiment is installed at the output end of the supercharger or the exhaust throttle valve. When the engine is running, the exhaust gas passes through the first panel 21, the second panel 22 and the third panel 23 in sequence during the process of passing through the guide pipe 1. Since the first panel 21 and the second panel 22 and the third panel 23 and the second panel 22 are arranged at an angle, the structure of the guide plate 2 is simplified, and the resistance to the exhaust gas flow is extremely small, which effectively reduces the back pressure of the entire exhaust system; the first panel 21, the second panel 22 and the third panel 23 flow along the exhaust gas. The urea injection port 13 is located upstream of the third panel 23 or upstream of the second panel 22 or upstream of the first panel 21, that is, after the urea is injected from the urea injection port 13, it at least passes through the turbulence of the third panel 23, so that the flow rate of the urea is increased, and the exhaust gas passes through the turbulence of the first panel 21, the second panel 22 and the third panel 23. The fast-flowing exhaust gas and the fast-flowing urea can be efficiently stirred and mixed to produce a chemical reaction, and the nitrogen oxides in the exhaust gas are decomposed, thereby meeting the use requirements of the engine.

[0043] In this embodiment, the urea injection port 13 is located upstream of the third panel 23, the urea injection port 13 and the middle of the second panel 22 are located in the same cross section of the guide tube 1, the urea nozzle is installed in the urea injection port 13 and is aligned with the second panel 22, and the urea is stirred by the exhaust gas during the process of spraying the urea to the second panel 22, so that the flow path of the urea is arc-shaped in the initial stage, and the urea and the exhaust gas continue to flow downstream, and finally the flow paths of the urea and the exhaust gas tend to overlap. In some other embodiments, the urea injection port 13 is located upstream of the second panel 22, when the urea injection port 13 is located upstream of the second panel 22, the urea injection port 13 is also located upstream of the third panel 23, or, the urea injection port 13 is located upstream of the first panel 21, and the urea injection port 13 is also located upstream of the third panel 23.

[0044] Optionally, the guide tube 1 is a curved cylindrical structure, the central axis of the air inlet port 11 and the central axis of the exhaust port 12 are located in the same plane as the second panel 22, and the central axis of the air inlet port 11 and the central axis of the exhaust port 12 are set at an angle.

[0045] Optionally, the first panel 21 is inclined toward a side away from the urea injection port 13, and the third panel 23 is inclined toward a side close to the urea injection port 13. The first panel 21, the second panel 22 and the third panel 23 are connected to form a Z-shaped structure, the first panel 21 and the second panel 22 are inclined to face the air intake port 11, and the second panel 22 is perpendicular to the air intake port 11. After the exhaust gas is input from the air intake port 11, a part of the exhaust gas originally flowing along the path aligned with the first panel 21 is guided by the inclined first panel 21 and the flow velocity is increased and merged into the path aligned with the third panel 23, and the first panel 21 has very little resistance to this part of the exhaust gas. This part of the exhaust gas and the exhaust gas originally flowing along the path aligned with the third panel 23 are guided by the third panel 23 to flow into the gap between the third panel 23 and the guide pipe 1, and finally discharged from the exhaust port 12. When the exhaust gas flows through the guide plate 2, a portion of the exhaust gas passes through the turbulence of the first panel 21, so that the flow rate of the exhaust gas is increased, and the urea and the exhaust gas are at least mixed by the turbulence of the third panel 23, thereby improving the efficiency of the chemical reaction between urea and the exhaust gas, and the content of nitrogen oxides in the exhaust gas is effectively reduced.

[0046] Optionally, the first panel 21 and the third panel 23 are arranged in parallel.

[0047] Optionally, a plurality of second through holes 221 are staggeredly arranged on the second panel 22. In the present embodiment, the second through holes 221 on the second panel 22 are arranged in two rows along the direction of exhaust gas flow, the first row of second through holes 221 is arranged in two rows, the second row of second through holes 221 is arranged in one row and is located behind the middle position of the two second through holes 221 in the first row. In the present embodiment, the urea nozzle is installed in the urea injection port 13 and is aligned with the second panel 22. The urea is stirred by the exhaust gas during the process of spraying to the second panel 22, so that the flow path of the urea is arc-shaped in the initial stage. Therefore, a part of the urea can pass through the second through holes 221 and come to the side of the second panel 22 away from the urea injection port 13, and react chemically with the exhaust gas at this position, which can improve the removal efficiency of nitrogen oxides in the exhaust gas.

[0048] Optionally, the guide plate 2 is provided in plurality, and the plurality of guide plates 2 are fixed to the inner wall of the guide tube 1 in parallel and at intervals. In the present embodiment, the guide plate 2 is made of stainless steel, and the guide plate 2 is provided in three numbers, and the three guide plates 2 are welded to the inner wall of the guide tube 1 to ensure the connection strength, and the three guide plates 2 are provided in parallel and at intervals, so as to force the exhaust gas to flow in layers, and improve the mixing efficiency of urea and exhaust gas. In some other embodiments, the guide plate 2 can be provided in more numbers, such as four or five, without increasing the flow resistance to the exhaust gas. Optionally, the plurality of guide plates 2 are provided at equal intervals, so that the exhaust gas is evenly layered.

[0049] Optionally, the guide plates 2 located in the guide pipe 1 are arranged in sequence along the direction of exhaust gas flow, and the guide plate 2 closest to the urea injection port 13 is also closest to the air intake port 11, and the guide plate 2 farthest from the urea injection port 13 is also farthest from the air intake port 11. Taking the arrangement of three guide plates 2 as an example, the three guide plates 2 divide the interior of the guide pipe 1 into four layers of exhaust gas flow gaps, the first layer of exhaust gas flow gap is located between the guide plate 2 closest to the urea injection port 13 and the inner wall of the guide pipe 1 with the urea injection port 13, the second layer of exhaust gas flow gap is located between the guide plate 2 closest to the urea injection port 13 and the guide plate 2 in the middle position, the third layer of exhaust gas flow gap is located between the guide plate 2 in the middle position and the guide plate 2 farthest from the urea injection port 13, and the fourth layer of exhaust gas flow gap is located between the guide plate 2 farthest from the urea injection port 13 and the inner wall of the guide pipe 1 without the urea injection port 13. Due to the stirring of urea by exhaust gas, the flow path of urea is arc-shaped in the initial stage. Therefore, after the urea passes through the second through hole 221 of the guide plate 2 closest to the urea injection port 13, part of the urea can react with the exhaust gas in the second layer of exhaust gas flow gap, and another part of the urea continues to pass through the second through hole 221 of the guide plate 2 in the middle position. Similarly, part of the urea can react with the exhaust gas in the third layer of exhaust gas flow gap, and another part of the urea continues to pass through the second through hole 221 of the guide plate 2 farthest from the urea injection port 13, and react with the exhaust gas in the fourth layer of exhaust gas flow gap. Multiple guide plates 2 are arranged in a sequential order along the exhaust gas flow direction, so that the urea with an arc-shaped flow path in the initial stage can pass through the second through holes 221 on the three guide plates 2 in sequence, avoiding the self-structure of the guide plate 2 blocking the urea and failing to achieve stratified stirring and mixing of urea and exhaust gas. By providing a plurality of guide plates 2 to stir and mix the urea and the tail gas in layers, it is possible to ensure uniform mixing and full reaction of the urea and the nitrogen oxides.

[0050] Optionally, a first notch 211 is provided on one side of the first panel 21 away from the second panel 22, and the first notch 211 is triangular. The first panel 21 with the first notch 211 can improve the flow disturbance capability of the exhaust gas and improve the reaction efficiency of the exhaust gas and urea.

[0051] Optionally, a plurality of first through holes 212 are further provided on the first panel 21. In the present embodiment, the first through holes 212 are waist-shaped holes, and two first through holes 212 are provided and symmetrically arranged on both sides of the first notch 211, so that a portion of the exhaust gas blown onto the first panel 21 can pass through the first through holes 212 and flow into the next layer of exhaust gas flow gap, thereby improving the turbulence capability of the exhaust gas and reducing the resistance to the exhaust gas.

[0052] Optionally, a second notch 231 is provided on one side of the third panel 23 away from the second panel 22, and the second notch 231 is triangular. The third panel 23 with the second notch 231 can improve the flow disturbance capability of the exhaust gas and urea. When the urea and the exhaust gas flow downstream and pass over the third panel 23, the third panel 23 with the second notch 231 can further stir the airflow, so that the urea and the nitrogen oxides are fully mixed and reacted.

[0053] Optionally, the flow guide tube 1 includes an inner ring layer, a middle ring layer and an outer ring layer from inside to outside, the inner ring layer and the outer ring layer are both made of stainless steel, and the middle ring layer is made of heat-insulating material. The middle ring layer can be heat-insulated to ensure the temperature controllability in the flow guide tube 1.

[0054] Optionally, a urea nozzle mounting seat 3 is welded at the urea injection port 13 , and the urea nozzle mounting seat 3 is made of stainless steel.

[0055] Optionally, a nitrogen oxide sensor mounting seat 4 is welded upstream of the urea injection port 13 , and the nitrogen oxide sensor mounting seat 4 is made of stainless steel.

[0056] Optionally, the intake port 11 is also welded with a first flange 5, which is connected to a supercharger or an exhaust throttle valve. A gasket and a clamping ring are arranged on the end face of the first flange 5, which can improve the sealing performance of the connection with the supercharger or the exhaust throttle valve. The exhaust port 12 is also welded with a second flange 6, which is used to connect to a downstream bellows.

[0057] This embodiment also discloses an engine, which includes the exhaust gas treatment mixer as described above.

[0058] In addition, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. Tail gas treatment mixer, characterized in that: include: A flow guide pipe (1), the flow guide pipe (1) comprising an intake port (11) and an exhaust port (12), exhaust gas is input from the intake port (11) and discharged from the exhaust port (12), a urea injection port (13) is provided on a side wall of the flow guide pipe (1), urea is input into the interior of the flow guide pipe (1) from the urea injection port (13); A guide plate (2), the guide plate (2) being fixedly arranged on the inner wall of the guide pipe (1), the guide plate (2) comprising a first panel (21), a second panel (22) and a third panel (23) which are sequentially connected and arranged along the direction of exhaust gas flow, the first panel (21) and the second panel (22) as well as the third panel (23) and the second panel (22) being arranged at an angle, and the urea injection port (13) being located upstream of the third panel (23) or upstream of the second panel (22) or upstream of the first panel (21); The flow velocity of the exhaust gas increases after passing through the first panel (21), the second panel (22) and the third panel (23); The first panel (21), the second panel (22) and the third panel (23) are connected to form a Z-shaped structure; The first panel (21) is also provided with a plurality of first through holes (212).

2. The exhaust gas treatment mixer according to claim 1, characterized in that: The first panel (21) is inclined toward a side away from the urea injection port (13), and the third panel (23) is inclined toward a side close to the urea injection port (13).

3. The exhaust gas treatment mixer according to claim 2, characterized in that: A first notch (211) is provided on a side of the first panel (21) away from the second panel (22), and the first notch (211) is triangular in shape.

4. The exhaust gas treatment mixer according to claim 2, characterized in that: A second notch (231) is provided on a side of the third panel (23) away from the second panel (22), and the second notch (231) is triangular in shape.

5. The exhaust gas treatment mixer according to claim 2, characterized in that: A plurality of second through holes (221) are arranged in an alternating manner on the second panel (22).

6. The exhaust gas treatment mixer according to claim 5, characterized in that: The guide plates (2) are arranged in plurality, and the plurality of guide plates (2) are fixed in parallel and at intervals on the inner wall of the guide tube (1).

7. The exhaust gas treatment mixer according to claim 6, characterized in that: The guide plates (2) located in the guide pipe (1) are arranged in sequence along the direction of exhaust gas flow, the guide plate (2) closest to the urea injection port (13) is also closest to the air intake port (11), and the guide plate (2) farthest from the urea injection port (13) is also farthest from the air intake port (11).

8. The exhaust gas treatment mixer according to claim 1, characterized in that: The flow guide tube (1) comprises, from inside to outside, an inner ring layer, a middle ring layer and an outer ring layer, the inner ring layer and the outer ring layer are both made of stainless steel material, and the middle ring layer is made of heat-insulating material.

9. The exhaust gas treatment mixer according to claim 8, characterized in that: A urea nozzle mounting seat (3) is welded at the urea injection port (13), and the urea nozzle mounting seat (3) is made of stainless steel.

10. The exhaust gas treatment mixer according to claim 8, characterized in that: A nitrogen oxide sensor mounting seat (4) is welded upstream of the urea injection port (13), and the nitrogen oxide sensor mounting seat (4) is made of stainless steel.

11. An engine, characterized in that It comprises the exhaust gas treatment mixer as described in any one of claims 1 to 10.

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