A four-way cross type static mixer for an SCR flue gas denitration system

Abstract

The utility model relates to a four -way cross type static mixer for SCR flue gas denitration system, including the mixer subassembly of setting in the flue, and the mixer subassembly includes end subassembly and circulation subassembly, end subassembly includes subassembly one and subassembly five, and the outside of subassembly one and subassembly five all are fixedly connected with the flue inner wall, and circulation subassembly includes subassembly two, subassembly three and subassembly four, and subassembly three and subassembly four are alternately arranged along X axle direction, and set up with subassembly two between any two adjacent subassembly three and subassembly four, and circulation subassembly sets up between end subassembly and carries out at least one circulation arrangement, and every circulation starting point of circulation subassembly and circulation end point are all subassembly two, the utility model discloses through setting up four -way mixing structure, and mixing effect is good, and the flow -guiding vane and the flue wall surface junction part have no flue gas dead angle, and it is difficult to ash deposit, and the uniformity coefficient is high, and the mixing efficiency is higher.

Description

Technical Field

[0001] This utility model relates to a four-way cross-type static mixer for SCR flue gas denitrification systems, belonging to the field of flue gas denitrification technology for coal-fired boilers. Background Technology

[0002] Selective catalytic reduction (SCR) technology, as the mainstream solution for industrial flue gas denitrification, efficiently converts ammonia and nitrogen oxides into nitrogen and water through a catalytic reaction, dominating the denitrification market. The uniformity of the mixing between flue gas and ammonia has the most significant impact on denitrification efficiency. Insufficient mixing and localized concentration imbalances lead to incomplete reactions, not only reducing denitrification efficiency but also causing residual unreacted ammonia to crystallize and deposit in the downstream air preheater, resulting in flow channel blockage and decreased heat exchange efficiency.

[0003] Static mixers, as flow field control devices without moving parts, have their core advantage in achieving efficient mixing of media by utilizing the fluid's own kinetic energy through a specific flow channel design. In SCR denitrification systems, such devices use internal components such as multi-stage baffles, spiral units, or corrugated configurations to forcibly cut and reorganize the flow paths of flue gas and ammonia, enhancing the turbulent diffusion effect and enabling flue gas and ammonia to diffuse and mix within an extremely short path, thereby significantly improving mixing uniformity.

[0004] The mixing effect of existing static mixers is limited to bidirectional diffusion in the flue, with a single disturbance direction and low uniformity of ammonia-nitrogen molar ratio distribution, thus requiring urgent improvement. Utility Model Content

[0005] To overcome the shortcomings of existing static mixers, such as being limited to bidirectional diffusion in the flue, having a single disturbance direction, and insufficient uniformity in the ammonia-nitrogen ratio distribution, this invention designs a four-way cross-type static mixer for SCR flue gas denitrification systems. By setting a four-way mixing structure, the mixing effect is good; there are no dead corners in the flue gas at the junction of the guide vanes and the flue wall, making it less prone to ash accumulation; the uniformity coefficient is high, and the mixing efficiency is even higher.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A four-way cross-type static mixer for an SCR flue gas denitrification system includes a mixer assembly disposed within a flue. The mixer assembly includes an end assembly and a circulation assembly. The end assembly includes component one and component five, the outer sides of which are fixedly connected to the inner wall of the flue. The circulation assembly includes component two, component three, and component four, which are alternately arranged along the X-axis, and component two is disposed between any two adjacent components three and component four. The circulation assembly is disposed between the end assemblies and is arranged in a cyclic arrangement at least once, with component two being the starting point and ending point of each cycle of the circulation assembly.

[0007] Furthermore, component one includes several guide vanes 1 and 2 alternately arranged along the Y-axis; guide vane 1 and guide vane 2 are both right-angled trapezoidal pieces of identical size and shape, the plane on which guide vane 1 is located forms an angle α with the horizontal plane, and guide vane 2 and guide vane 1 are arranged symmetrically around the X-axis centerline after rotating 180°; the upper base of guide vane 1 is 'a', the value of 'a' ranges from 150mm to 350mm, and the lower base of guide vane 1 is 'c'. The value of c ranges from 600mm to 900mm. The right-angled side of the first guide vane is b, which ranges from 500mm to 1100mm. The distance between the first guide vane and the second guide vane is e, which ranges from 500mm to 1000mm. The angle between the first and second guide vanes and the horizontal direction is α, which ranges from 50° to 75°. The right-angled sides of the first and second guide vanes are both fixed to the inner wall of the flue.

[0008] Furthermore, component three includes several guide vanes three and four alternately arranged along the Y-axis; guide vanes three and four are right-angled trapezoidal pieces of identical size and shape, the plane containing guide vane three forms an angle θ with the horizontal plane, and guide vane four and guide vane three are arranged in a mirror-symmetric manner along the X-axis; the upper base of guide vane three is i, the value of i ranges from 300mm to 700mm, the lower base of guide vane three is k, k=i+gcosγ, the right-angled side of guide vane three is j, the value of j ranges from 500mm to 1100mm, the distance between guide vane three and guide vane four is m, the value of m ranges from 500mm to 1000mm, and the angle between guide vane three and guide vane four and the horizontal direction is θ, the value of θ ranges from 50° to 75°.

[0009] Furthermore, component two includes several guide vanes five and six alternately arranged along the Y-axis; the spacing between each component two along the X-axis is h, where h ranges from 800mm to 1300mm; guide vanes five and six are rectangular pieces of the same size, the plane containing guide vane five forms an angle γ with the horizontal plane, and guide vanes six and five are arranged centrally symmetrically with the Z-axis as the center of symmetry; the width of guide vane five is f, where f ranges from 600mm to 900mm, the height of guide vane five is g, where g ranges from 500mm to 1100mm, the angle between guide vanes five and six and the horizontal direction is γ, where γ ranges from 50° to 75°, and the angle between guide vanes five and six is ​​δ, where δ ranges from 30° to 80°.

[0010] Furthermore, components four and three are arranged symmetrically with a 180° rotation along the Z-axis centerline.

[0011] Furthermore, Component 5 and Component 1 are arranged symmetrically with a 180° rotation along the Y-axis centerline.

[0012] Furthermore, the number of guide vanes 1, 2, 3, 4, 5, and 6 are the same, and their heights in the Z-axis direction are all the same.

[0013] Furthermore, in component one, the inclined side of each guide vane one is fixed on the leeward side of guide vane five, and the inclined side of each guide vane two is fixed on the windward side of guide vane six; in component five, the inclined side of each guide vane one is fixed on the windward side of guide vane five, and the inclined side of each guide vane two is fixed on the leeward side of guide vane six.

[0014] Furthermore, in components three and four, the inclined side of each guide vane three is fixed on the windward surface of the previous guide vane five along the positive X-axis direction, and the inclined side of each guide vane four is fixed on the windward surface of the next guide vane six along the positive X-axis direction.

[0015] Compared with the prior art, this utility model has the following features and beneficial effects: This invention achieves enhanced turbulence across the entire cross-section of the flue by setting a static mixer with a four-way mixing structure, significantly improving the uniformity coefficient; there are no dead zones for flue gas at the junction of the mixer and the flue wall, making it less prone to ash accumulation; by setting a four-way mixing structure, it achieves a dual optimization of significantly improved uniformity coefficient and reduced drag coefficient, promoting improved mixing efficiency. Attached Figure Description

[0016] Figure 1 This is an axonometric view of the four-way cross-type static mixer of this utility model inside the flue; Figure 2 This is a schematic diagram showing the position of the four-way cross-type static mixer of this utility model inside the flue; Figure 3 This is a schematic diagram of the structure of the four-way cross-type static mixer of this utility model; Figure 4 This is a schematic diagram of component one and component three of this utility model; Figure 5 This is a schematic diagram of component two of this utility model; Figure 6 This is an enlarged view of the guide vane of this utility model; Figure 7 This is a side view of the component of this utility model; Figure 8 This is a magnified view of the flow guide plate of this utility model; Figure 9 This is a three-dimensional enlarged view of the flow guide plate of this utility model; Figure 10 This is a three-side view of the component of this utility model; Figure 11 This is a schematic diagram of two cross-sections of the component of this utility model; Figure 12These are top views of component one and component five of this utility model; Figure 13 These are top views of component three and component four of this utility model; Figure 14 This utility model is NH3 / NO X Curve showing the variation of molar ratio distribution uniformity Cv value with mixing distance.

[0017] The attached diagrams are labeled as follows: 10, Component 1; 20, Component 2; 30, Component 3; 40, Component 4; 50, Component 5; 11, Guide vane 1; 12, Guide vane 2; 31, Guide vane 3; 32, Guide vane 4; 21, Guide vane 5; 22, Guide vane 6; 100, Mixer assembly; 200, Flue. Detailed Implementation

[0018] The present invention will now be described in more detail with reference to the embodiments.

[0019] like Figures 1 to 13 As shown, the four-way cross-type static mixer for the SCR flue gas denitrification system in this embodiment includes a mixer assembly 100 disposed in the flue 200, and the mixer assembly 100 includes an end assembly and a circulation assembly.

[0020] The end components include component 10 and component 50, and the outer sides of both component 10 and component 50 are fixedly connected to the inner wall of the flue 200.

[0021] The loop component includes component 20, component 30 and component 40. Component 30 and component 40 are alternately arranged along the X-axis direction, and component 20 is arranged between any two adjacent components 30 and component 40, forming a stable alternating connection structure.

[0022] The loop component is set between the end components and is arranged in a loop at least once. The start point and end point of each loop component are component 20.

[0023] In this embodiment, the direction of flue gas inflow is recorded as the positive direction of the Z-axis, the alternating directions of component three 30 and component four 40 are recorded as the positive direction of the X-axis, and the positive direction of the Y-axis is the direction that is perpendicular to both the Z-axis and the X-axis.

[0024] In this embodiment, the loop unit is the smallest loop unit, which is composed of component 20, component 30, component 20, component 40, and component 20 arranged alternately along the X-axis.

[0025] To add a loop, it can be Component 2 20, Component 3 30, Component 2 20, Component 4 40, Component 2 20, Component 3 30 and Component 2 20, or Component 2 20, Component 3 30, Component 2 20, Component 4 40, Component 2 20, Component 3 30, Component 2 20, Component 4 40 and Component 2 20.

[0026] Component 10 includes several guide vanes 11 and 22 arranged alternately along the Y-axis.

[0027] Both guide vane 11 and guide vane 22 are right-angled trapezoidal plates of the same size and shape. The plane on which guide vane 11 is located is inclined at an angle α to the horizontal plane. Guide vane 22 and guide vane 11 are arranged symmetrically around the X-axis centerline by rotating 180°.

[0028] The upper base of guide vane 11 is 'a', with a value ranging from 150mm to 350mm. The lower base of guide vane 11 is 'c', with a value ranging from 600mm to 900mm. The right-angled side of guide vane 11 is 'b', with a value ranging from 500mm to 1100mm. The distance between guide vane 11 and guide vane 2 12 is 'e', ​​with a value ranging from 500mm to 1000mm. The angle between guide vane 11 and guide vane 2 12 and the horizontal direction is 'α', with a value ranging from 50° to 75°.

[0029] The right-angled sides of guide vane 11 and guide vane 22 are both fixed to the inner wall of flue 200.

[0030] Component 30 includes several guide vanes 31 and 42 arranged alternately along the Y-axis.

[0031] Both guide vane 31 and guide vane 42 are right-angled trapezoidal plates of the same size and shape. The plane containing guide vane 31 is inclined at an angle θ to the horizontal plane. Guide vane 42 and guide vane 31 are arranged in a mirror image symmetrical arrangement along the X-axis.

[0032] The top of the guide vane 31 is i, and the value of i is in the range of 300mm-700mm. The guide vane 3 (31) is k, k=i+gcosγ. The side of the guide vane 3 (31) is j, and the value of j is in the range of 500mm-1100mm. The distance between the guide vane 31 and the guide vane 4 32 is m, and the value of m is in the range of 500mm-1000mm. The angle between the guide vane 31 and the guide vane 4 32 and the horizontal direction is θ, and the value of θ is in the range of 50°-75°.

[0033] Component 20 includes several guide vanes 5 21 and 6 22 that are alternately arranged along the Y-axis.

[0034] The spacing between each component 20 along the X-axis is h, and the value of h ranges from 800mm to 1300mm.

[0035] Both guide vane 5 21 and guide vane 6 22 are rectangular pieces of the same size. The plane containing guide vane 5 21 is inclined at an angle γ to the horizontal plane. Guide vane 6 22 and guide vane 5 21 are arranged in a centrally symmetrical manner with the Z-axis as the center of symmetry.

[0036] The width of guide vane 5 21 is f, and the value of f ranges from 600mm to 900mm. The height of guide vane 5 21 is g, and the value of g ranges from 500mm to 1100mm. The angle between guide vane 5 21 and guide vane 6 22 and the horizontal direction is γ, and the value of γ ranges from 50° to 75°. The angle between guide vane 5 21 and guide vane 6 22 is δ, and the value of δ ranges from 30° to 80°.

[0037] By setting Component 10 and Component 50 as inclined structures with an angle of α to the horizontal plane, the near-wall flow field distribution is significantly improved, the low velocity region formed by traditional right-angle connections is eliminated, the flow velocity of flue gas boundary layer is increased, and the risk of ash accumulation is reduced; Component 10 and Component 50 and the four corners of the flue 200 have airflow channels, which can avoid local ash accumulation.

[0038] Component 20 deflects the airflow in both positive and negative directions along the X-axis.

[0039] Component 40 and Component 30 are arranged symmetrically with a 180° rotation along the Z-axis centerline.

[0040] Component 50 and Component 10 are arranged symmetrically with a 180° rotation along the Y-axis centerline.

[0041] The airflow is mixed simultaneously in four directions by arranging components 20, 30, and 40 in an alternating flow-guiding configuration.

[0042] Component 30 deflects the airflow in the positive Y-axis direction, while component 40 deflects the airflow in the negative Y-axis direction. The two components symmetrically change the airflow direction, guiding the airflow to form a symmetrical flow direction, reducing local eddies and turbulence, lowering flow resistance and energy consumption, and improving airflow uniformity and stability. Component 40 is a symmetrical arrangement of component 30, which balances the forces on the flue 200, avoids stress concentration, and improves the stability of equipment operation.

[0043] By setting a periodic cyclic layout of the circulating components, the flow field alternately flips. When the flue gas passes through the mixer component 100, the multi-dimensional velocity gradient field generates a forced shearing effect, forming multi-directional rotating turbulent vortices in the flue gas. These vortices collide and split with each other, continuously stirring and mixing the central airflow and the edge airflow in the flue 200. Finally, a violent energy transfer effect is formed in the entire flue 200, achieving full mixing of flue gas and ammonia.

[0044] The number of guide vanes 11, 21, 31, 43, 52, and 62 is the same, and their heights in the Z-axis direction are all the same.

[0045] In component 10, the inclined side of each guide vane 11 is fixed on the leeward side of guide vane 5 21, and the inclined side of each guide vane 22 is fixed on the windward side of guide vane 6 22.

[0046] In component 50, the inclined sides of each guide vane 11 are fixed on the windward side of guide vane 21, and the inclined sides of each guide vane 22 are fixed on the leeward side of guide vane 622.

[0047] In components 30 and 40, the hypotenuse of each guide vane 31 is fixed on the windward surface of the previous guide vane 5 21 along the positive X-axis, and the hypotenuse of each guide vane 4 32 is fixed on the windward surface of the next guide vane 6 22 along the positive X-axis.

[0048] In this embodiment, the windward side refers to the side facing the direction of the smoke impact, and the leeward side refers to the side away from the direction of the smoke impact.

[0049] like Figure 14 As shown, the flue gas volume in this embodiment is 486,000 m³. 3 / h, flue gas temperature 350℃, NH3 / NO at a mixing distance of 10m X The molar ratio distribution uniformity Cv value was 3.41%, and the NH3 / NO ratio at a mixing distance of 15m was... X The molar ratio distribution uniformity Cv value was 2.28%, and the NH3 / NO ratio at a mixing distance of 20 m was... X The molar ratio distribution uniformity Cv value was 1.79%, which is far superior to the NH3 / NO3 ratio in the national standard GB / T 21509-2008. X The technical requirement is that the uniformity of the molar ratio distribution is less than 5%. According to statistics, the uniformity coefficient of the four-way cross-type static mixer is 94.38%, the resistance loss coefficient is 2.54, and the mixing efficiency is 37.20%.

[0050] The working principle of this utility model is as follows: Before use, a mixer assembly 100 is set according to the width of the flue 200. When the flue gas entering the flue 200 and the ammonia gas injected by the ammonia injection grid pass through the mixer assembly 100, the multi-dimensional velocity gradient field generates a forced shearing effect, forming a multi-directional rotating turbulent vortex in the flue gas. These vortices collide and split with each other, continuously stirring and mixing the airflow in the center and the airflow at the edge of the flue 200. Finally, a violent energy transfer effect is formed in the entire flue 200, achieving full mixing of flue gas and ammonia gas.

[0051] Component 10 and Component 40 deflect the airflow in the negative Y-axis direction, Component 30 and Component 50 deflect the airflow in the positive Y-axis direction, and Component 20 deflects the airflow in both the positive and negative X-axis directions. The arrangement of the mixer component 100 enables the airflow to be mixed simultaneously in four directions.

[0052] In the description of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. 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 a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0054] Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

Claims

1. A four-way cross-type static mixer for an SCR flue gas denitrification system, characterized in that: Includes a mixer assembly (100) disposed within a flue (200), the mixer assembly (100) including an end assembly and a circulation assembly; The end assembly includes component one (10) and component five (50), and the outer sides of both component one (10) and component five (50) are fixedly connected to the inner wall of the flue (200); The loop component includes component two (20), component three (30) and component four (40). Component three (30) and component four (40) are alternately arranged along the X-axis direction, and component two (20) is arranged between any two adjacent components three (30) and components four (40). The loop component is set between the end components and is arranged in a loop at least once. The start point and end point of each loop component are component two (20).

2. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: Component 1 (10) includes several guide vanes 1 (11) and guide vanes 2 (12) arranged alternately along the Y-axis. Both the first guide vane (11) and the second guide vane (12) are right-angled trapezoidal plates of the same size and shape. The plane where the first guide vane (11) is located is at an angle α to the horizontal plane. The second guide vane (12) and the first guide vane (11) are arranged symmetrically with a 180° rotation along the X-axis center line. The upper base of the first guide vane (11) is a, and the value of a is 150mm-350mm. The lower base of the first guide vane (11) is c, and the value of c is 600mm-900mm. The right-angled side of the first guide vane (11) is b, and the value of b is 500mm-1100mm. The distance between the first guide vane (11) and the second guide vane (12) is e, and the value of e is 500mm-1000mm. The angle between the first guide vane (11) and the second guide vane (12) and the horizontal direction is α, and the value of α is 50°-75°. The right-angled sides of guide vane one (11) and guide vane two (12) are fixed to the inner wall of the flue (200).

3. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: Component 3 (30) includes several guide vanes 3 (31) and 4 (32) arranged alternately along the Y-axis. Both the third (31) and the fourth (32) of the flow guide are right-angled trapezoidal plates of the same size and shape. The plane on which the third (31) is located is at an angle θ to the horizontal plane. The fourth (32) and the third (31) of the flow guide are mirror images of each other along the X-axis. The upper base of the guide vane 3 (31) is i, and the value of i is in the range of 300mm-700mm. The lower base of the guide vane 3 (31) is k, k=i+gcosγ. The right-angled side of the guide vane 3 (31) is j, and the value of j is in the range of 500mm-1100mm. The distance between the guide vane 3 (31) and the guide vane 4 (32) is m, and the value of m is in the range of 500mm-1000mm. The angle between the guide vane 3 (31) and the guide vane 4 (32) and the horizontal direction is θ, and the value of θ is in the range of 50°-75°.

4. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: Component 2 (20) includes several guide vanes 5 (21) and 6 (22) arranged alternately along the Y-axis. The spacing between each component (20) along the X-axis is h, and the value of h ranges from 800mm to 1300mm. Both the fifth (21) and the sixth (22) of the flow guide are rectangular pieces of the same size. The plane on which the fifth (21) is located is at an angle γ to the horizontal plane. The sixth (22) and the fifth (21) of the flow guide are arranged in a centrally symmetrical manner with the Z-axis as the center of symmetry. The width of guide vane five (21) is f, and the value of f is 600mm-900mm. The height of guide vane five (21) is g, and the value of g is 500mm-1100mm. The angle between guide vane five (21) and guide vane six (22) and the horizontal direction is γ, and the value of γ is 50°-75°. The angle between guide vane five (21) and guide vane six (22) is δ, and the value of δ is 30°-80°.

5. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: Components four (40) and three (30) are arranged symmetrically with a 180° rotation along the center line of the Z-axis.

6. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: Component 5 (50) and Component 1 (10) are arranged symmetrically with a 180° rotation along the center line of the Y axis.

7. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 1, characterized in that: The number of guide vanes 1 (11), 2 (12), 3 (31), 4 (32), 5 (21) and 6 (22) are the same and their heights in the Z-axis direction are the same.

8. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 2, characterized in that: In component one (10), the hypotenuse of each guide vane one (11) is fixed on the leeward side of guide vane five (21), and the hypotenuse of each guide vane two (12) is fixed on the windward side of guide vane six (22). In component five (50), the inclined side of each guide vane one (11) is fixed on the windward side of guide vane five (21), and the inclined side of each guide vane two (12) is fixed on the leeward side of guide vane six (22).

9. A four-way cross-type static mixer for an SCR flue gas denitrification system according to claim 3, characterized in that: In components three (30) and four (40), the hypotenuse of each guide vane three (31) is fixed on the windward surface of the previous guide vane five (21) along the positive X-axis, and the hypotenuse of each guide vane four (32) is fixed on the windward surface of the next guide vane six (22) along the positive X-axis.

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