A laminated SCR flue gas denitration mixing device and mounting structure thereof
Patent Information
- Application Number
- CN202522581430.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2035-12-04
AI Technical Summary
然而，燃烧煤种变化、磨组合方式改变、燃烧器调整等因素会导致SCR入口NOx浓度分布和流场发生明显变化，进而使氨氮摩尔比的均匀性明显变差，氨氮摩尔比过小的区域，会导致局部脱硝效率不能达标，而氨氮摩尔比过大的区域，则氨逃逸率超标，进而引发下游空预器堵塞、腐蚀、排放超标等系列问题，还会造成能源浪费
[0025]本实用新型层叠型SCR烟气脱硝混合装置及其安装结构，通过层叠式导流混合结构的设计，可对烟气起到有效的引导和均化的效果，有效改善SCR脱硝入口烟气中NOX的分布均匀性，提高烟气中NOx和还原剂的混合均匀性，改善脱硝效果。
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Figure CN224877720U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a stacked SCR flue gas denitrification mixing device and its installation structure, belonging to the field of coal-fired flue gas denitrification technology. Background Technology
[0002] SCR (Selective Catalytic Reduction) flue gas denitrification technology is a NOx emission reduction technology that uses a reducing agent (such as liquid ammonia, urea, and ammonia water) in the presence of a catalyst to selectively react with NOx in flue gas, producing pollution-free N2 and H2O. Due to its stability and high efficiency, it is adopted by most coal-fired power plant denitrification projects.
[0003] The key to SCR flue gas denitrification is achieving uniform mixing of NOx and reducing agent in the flue gas. However, factors such as changes in the type of coal burned, alterations in the mill assembly, and burner adjustments can lead to significant changes in the NOx concentration distribution and flow field at the SCR inlet, resulting in a marked deterioration in the uniformity of the ammonia-nitrogen molar ratio. In areas with an excessively low ammonia-nitrogen molar ratio, local denitrification efficiency may fail to meet standards, while in areas with an excessively high ammonia-nitrogen molar ratio, ammonia slip may exceed the standard, leading to a series of problems such as blockage, corrosion, and excessive emissions in the downstream air preheater, as well as energy waste.
[0004] To effectively improve the mixing effect of NOx and reducing agent, the inventors developed a stacked SCR flue gas denitrification mixing device, which can effectively improve the NO content in the inlet flue gas of SCR denitrification. X The uniformity of NOx distribution improves the mixing uniformity of NOx and reducing agent in flue gas, thereby improving the denitrification effect. Utility Model Content
[0005] This invention provides a stacked SCR flue gas denitrification mixing device and its installation structure. Through the design of the stacked mixing structure, the inlet flue gas for SCR denitrification can be effectively homogenized, increasing the NO content in the flue gas. X This improves the uniformity of NOx distribution, thereby enhancing the mixing uniformity of NOx and reducing agent in the flue gas and improving the denitrification effect.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0007] A stacked SCR flue gas denitrification mixing device includes a first flow guiding mixing layer and a second flow guiding mixing layer;
[0008] The first flow mixing layer is provided with two or more rows of first oblique holes and two or more rows of second oblique holes. The first oblique holes and the second oblique holes are arranged alternately, that is, the first flow mixing layer is provided with one row of first oblique holes, one row of second oblique holes, one row of first oblique holes, one row of second oblique holes, and so on. The axial direction of the first oblique hole and the axial direction of the second oblique hole form an angle of 45 to 65 degrees.
[0009] The second flow mixing layer is provided with two or more rows of third oblique holes and two or more rows of fourth oblique holes. The third oblique holes and fourth oblique holes are arranged alternately, that is, the second flow mixing layer is provided with one row of third oblique holes, one row of fourth oblique holes, one row of third oblique holes, one row of fourth oblique holes, and so on. The axial direction of the third oblique hole and the axial direction of the fourth oblique hole form an angle of 45 to 65 degrees.
[0010] The second flow guide mixture is superimposed on the surface of the first flow guide mixture layer to form a stacked structure; the third oblique hole is connected to the first oblique hole, and the central axis of the third oblique hole coincides with the central axis of the first oblique hole to form an extension hole of the first oblique hole (that is, the third oblique hole forms an extension hole of the first oblique hole), or the central axis of the third oblique hole and the central axis of the first oblique hole form an angle of 115~135° to form a turning hole of the first oblique hole (that is, the third oblique hole forms a turning hole of the first oblique hole); the fourth oblique hole is connected to the second oblique hole, and the central axis of the fourth oblique hole coincides with the central axis of the second oblique hole to form an extension hole of the second oblique hole (that is, the fourth oblique hole forms an extension hole of the second oblique hole), or the central axis of the fourth oblique hole and the central axis of the second oblique hole form an angle of 115~135° to form a turning hole of the second oblique hole (that is, the fourth oblique hole forms a turning hole of the second oblique hole).
[0011] The design of the first and second oblique holes arranged alternately and at angles to each other on the first flow guiding and mixing layer can effectively guide and homogenize the flue gas; at the same time, the introduction of the second flow guiding and mixing layer through the stacked structure allows the flue gas passing through the first flow guiding and mixing layer to be extended or turned by the third and fourth oblique holes, which further achieves the homogenization effect.
[0012] To facilitate preparation and assembly, the number of first oblique holes in each column of first oblique holes is equal; the number of second oblique holes in each column of second oblique holes is equal.
[0013] To ensure homogenization while facilitating preparation and assembly, all first oblique holes and all second oblique holes are arranged in a matrix on the first flow-guiding mixing layer; all third oblique holes and all fourth oblique holes are arranged in a matrix on the second flow-guiding mixing layer.
[0014] To facilitate fabrication and ensure sufficient diffusion area, the first and second oblique holes have square cross-sections. The oblique holes are spaced apart by inclined metal plates. The metal is preferably stainless steel.
[0015] The installation structure of the above-mentioned stacked SCR flue gas denitrification mixing device includes a first horizontal flue, a first corner transition flue, a vertical flue, a second corner transition flue, and a second horizontal flue sequentially arranged between the economizer and the SCR flue gas denitrification device. The stacked SCR flue gas denitrification mixing device is installed in the first horizontal flue, and the first guiding mixing layer covers the flow cross-section of the first horizontal flue. The direction from the first guiding mixing layer to the second guiding mixing layer is consistent with the flue gas flow direction.
[0016] The economizer and SCR flue gas denitrification device mentioned above are connected by a first horizontal flue, a first corner transition flue, a vertical flue, a second corner transition flue, and a second horizontal flue, which are connected in sequence. The connections of the economizer, SCR flue gas denitrification device, and flues all refer to existing mature technologies.
[0017] To improve the homogenization effect, the angle between the axis of the first inclined hole and the flue gas flow direction is equal to the angle between the axis of the second inclined hole and the flue gas flow direction.
[0018] The aforementioned flue gas flow direction refers to the main direction of flue gas flow, that is, from upstream to downstream. This application should not be limited or interpreted based on the local flue gas flow direction.
[0019] As one preferred implementation, the angle between the axis of the first inclined hole and the flue gas flow direction is 30°, and the angle between the axis of the second inclined hole and the flue gas flow direction is 30°.
[0020] To achieve better homogenization, the central axis of the third inclined hole forms a 120° angle with the central axis of the first inclined hole, forming a turning hole for the first inclined hole; the central axis of the fourth inclined hole forms a 120° angle with the central axis of the second inclined hole, forming a turning hole for the second inclined hole.
[0021] The first corner transition flue is provided with parallel and spaced first arc-shaped guide plates, and the second corner transition flue is provided with parallel and spaced second arc-shaped guide plates; an ammonia injection grid is provided in the vertical flue, a first mixer is provided in the vertical flue downstream of the ammonia injection grid, and a second mixer is provided in the second horizontal flue.
[0022] The first mixer and the second mixer described above respectively cover the flow cross sections of the vertical flue and the second horizontal flue; both the first mixer and the second mixer can adopt the same structure as the first flow guiding mixing layer.
[0023] The second horizontal flue sidewall directly above the SCR flue gas denitrification device is an inclined structure that slopes downward (gradually decreasing from upstream to downstream). Parallel and spaced third guide plates are provided on the inclined structure, and each third guide plate gradually increases in length from upstream to downstream.
[0024] Any technologies not mentioned in this utility model are based on existing technologies.
[0025] This utility model relates to a stacked SCR flue gas denitrification mixing device and its installation structure. Through the design of the stacked flow-guiding mixing structure, it can effectively guide and homogenize the flue gas, effectively improving the NO content in the inlet flue gas of the SCR denitrification process. X The uniformity of NOx distribution improves the mixing uniformity of NOx and reducing agent in flue gas, thereby improving the denitrification effect. Attached Figure Description
[0026] Figure 1 This is the denitrification structure before installation of the stacked SCR flue gas denitrification mixing device of this utility model;
[0027] Figure 2 This is the denitrification structure after installation of the stacked SCR flue gas denitrification mixing device of this utility model;
[0028] Figure 3 This is a schematic diagram of the structure of the first flow-guiding mixing layer of this utility model;
[0029] Figure 4 for Figure 3 View from direction A;
[0030] Figure 5 for Figure 3 View from direction B (relative to) Figure 3 (Shrinkage)
[0031] Figure 6 This is a schematic diagram of the structure of the second flow-guiding mixing layer of this utility model (the dashed line represents the first flow-guiding mixing layer).
[0032] Figure 7 for Figure 6 View from direction A;
[0033] Figure 8 for Figure 6 View from direction B (relative to) Figure 6 (There is a reduction; the dashed line represents the first flow-guiding mixing layer).
[0034] Figure 9 A perspective view of the first flow-guiding and mixing layer of the utility model;
[0035] Figure 10 A perspective view of the second flow-guiding mixing layer of the utility model;
[0036] Figure 11 This is a perspective view of the layered SCR flue gas denitrification mixing device of this utility model;
[0037] In the diagram, 1 represents the first guiding mixing layer, 11 the first inclined hole, 12 the second inclined hole, 2 the second guiding mixing layer, 21 the third inclined hole, 22 the fourth inclined hole, 3 the economizer outlet flue, 4 the first horizontal flue, 5 the first corner transition flue, 51 the first arc-shaped guide plate, 6 the vertical flue, 61 the ammonia injection grid, 62 the first mixer, 7 the second corner transition flue, 71 the second arc-shaped guide plate, 8 the second horizontal flue, 81 the second mixer, 82 the third guide plate, and 9 the SCR flue gas denitrification device. a indicates the flue gas flow direction. Detailed Implementation
[0038] To better understand this utility model, the following embodiments further illustrate its content, but the content of this utility model is not limited to the following embodiments.
[0039] The directional terms in this application, such as "center," "vertical," "horizontal," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," are based on the appendix. Figure 2 The orientation or positional relationship shown or in use is for the purpose of describing this application only, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0040] Example 1
[0041] like Figure 2 As shown, a stacked SCR flue gas denitrification mixing device includes a first flow guiding mixing layer and a second flow guiding mixing layer;
[0042] like Figure 2-5 As shown, the first flow mixing layer is provided with two or more rows of first oblique holes and two or more rows of second oblique holes, the first oblique holes and the second oblique holes are arranged alternately, and the axial direction of the first oblique hole and the axial direction of the second oblique hole form a 60° angle.
[0043] like Figure 6-8 As shown, the second flow mixing layer is provided with two or more rows of third oblique holes and two or more rows of fourth oblique holes, the third oblique holes and the fourth oblique holes are arranged alternately, and the axial direction of the third oblique hole and the axial direction of the fourth oblique hole form a 60° angle.
[0044] The second flow guide mixture is superimposed on the surface of the first flow guide mixture layer to form a stacked structure; the third oblique hole is connected to the first oblique hole, and the central axis of the third oblique hole coincides with the central axis of the first oblique hole to form an extension hole of the first oblique hole, or the central axis of the third oblique hole and the central axis of the first oblique hole form a 120° angle to each other to form a turning hole of the first oblique hole; the fourth oblique hole is connected to the second oblique hole, and the central axis of the fourth oblique hole coincides with the central axis of the second oblique hole to form an extension hole of the second oblique hole, or the central axis of the fourth oblique hole and the central axis of the second oblique hole form a 120° angle to each other to form a turning hole of the second oblique hole.
[0045] The design of the first and second oblique holes arranged alternately and at angles to each other on the first flow guiding and mixing layer can effectively guide and homogenize the flue gas; at the same time, the introduction of the second flow guiding and mixing layer through the stacked structure allows the flue gas passing through the first flow guiding and mixing layer to be extended or turned by the third and fourth oblique holes, which further achieves the homogenization effect.
[0046] Example 2
[0047] Based on Example 1, the following improvements were made: To facilitate preparation and assembly, the number of first oblique holes in each column of first oblique holes is equal; the number of second oblique holes in each column of second oblique holes is equal. To ensure homogenization while facilitating preparation and assembly, all first oblique holes and all second oblique holes are arranged in a matrix on the first flow-guiding mixing layer; all third oblique holes and all fourth oblique holes are arranged in a matrix on the second flow-guiding mixing layer. To facilitate preparation and ensure diffusion area, the cross-sections of the first and second oblique holes are square. Each oblique hole is separated by a 2mm stainless steel plate.
[0048] The installation structure of the above-mentioned stacked SCR flue gas denitrification mixing device includes a first horizontal flue, a first corner transition flue, a vertical flue, a second corner transition flue, and a second horizontal flue sequentially arranged between the economizer and the SCR flue gas denitrification device. The stacked SCR flue gas denitrification mixing device is installed in the first horizontal flue, and the first guiding mixing layer covers the flow cross-section of the first horizontal flue. The direction from the first guiding mixing layer to the second guiding mixing layer is consistent with the flue gas flow direction.
[0049] Example 3
[0050] Based on Example 2, the following improvements were made: In order to improve the homogenization effect, the angle between the axis of the first inclined hole and the flue gas flow direction and the angle between the axis of the second inclined hole and the flue gas flow direction are both 30°.
[0051] Example 4
[0052] Based on Example 3, the following improvements were made: In order to achieve a better homogenization effect, the central axis of the third oblique hole forms a 120° angle with the central axis of the first oblique hole to form a turning hole of the first oblique hole; the central axis of the fourth oblique hole forms a 120° angle with the central axis of the second oblique hole to form a turning hole of the second oblique hole.
[0053] Example 5
[0054] Based on Example 3, the following improvements were made: the central axis of the third oblique hole coincides with the central axis of the first oblique hole to form an extension hole of the first oblique hole, and the central axis of the fourth oblique hole coincides with the central axis of the second oblique hole to form an extension hole of the second oblique hole.
[0055] Example 6
[0056] Based on Embodiment 4 or 5, the following improvements were made: four parallel and spaced-apart first arc-shaped guide plates were provided at the first corner transition flue, and four parallel and spaced-apart second arc-shaped guide plates were provided at the second corner transition flue; an ammonia injection grid was provided in the vertical flue, a first mixer was provided in the vertical flue downstream of the ammonia injection grid, and a second mixer was provided in the second horizontal flue. The first mixer and the second mixer respectively covered the flow cross-section of the vertical flue and the second horizontal flue; in this example, both the first mixer and the second mixer adopted the same structure as the first guide mixing layer.
[0057] Example 7
[0058] Based on Example 6, the following improvements were made: The sidewall of the second horizontal flue directly above the SCR flue gas denitrification device is an inclined structure that slopes downwards (gradually decreasing from upstream to downstream). Four parallel and spaced third guide plates are provided on the inclined structure. From upstream to downstream, the intervals between the four third guide plates are 2500mm, 2100mm, and 1800mm respectively. The interval between the last third guide plate and the sidewall of the SCR flue gas denitrification device is 1500mm. The lengths of the four third guide plates are 125mm, 150mm, 180mm, and 180mm respectively, with each third guide plate gradually increasing in length from upstream to downstream. In this example, there are nine rows each of the first, second, third, and fourth inclined holes. The width of the second guiding mixing layer is smaller than the width of the first guiding mixing layer. The first and second inclined holes in the middle two rows are respectively connected to the third and fourth inclined holes.
[0059] The above-described stacked SCR flue gas denitrification mixing devices and their installation structures, through the design of a stacked flow-guiding mixing structure, can effectively guide and homogenize the flue gas, effectively improving the NO content in the SCR denitrification inlet flue gas. XThe uniformity of NOx distribution and the uniformity of mixing of NOx and reducing agent in flue gas are improved, thus improving the denitrification effect. Compared with the stacked SCR flue gas denitrification mixing device before installation, the ammonia slip rate is reduced by 80%-90% after installation.
Claims
1. A stacked SCR flue gas denitrification mixing device, characterized in that: Includes a first flow-guiding mixing layer and a second flow-guiding mixing layer; The first flow mixing layer is provided with two or more rows of first oblique holes and two or more rows of second oblique holes, the first oblique holes and the second oblique holes are arranged alternately, and the axial direction of the first oblique holes and the axial direction of the second oblique holes form an angle of 45~65°. The second flow mixing layer is provided with two or more rows of third oblique holes and two or more rows of fourth oblique holes. The third oblique holes and fourth oblique holes are arranged alternately, and the axial direction of the third oblique holes and the axial direction of the fourth oblique holes form an angle of 45° to 65°. The second flow guide mixture is superimposed on the surface of the first flow guide mixture layer to form a stacked structure; the third oblique hole is connected to the first oblique hole, and the central axis of the third oblique hole coincides with the central axis of the first oblique hole to form an extension hole of the first oblique hole, or the central axis of the third oblique hole and the central axis of the first oblique hole form an angle of 115~135° to form a turning hole of the first oblique hole; the fourth oblique hole is connected to the second oblique hole, and the central axis of the fourth oblique hole coincides with the central axis of the second oblique hole to form an extension hole of the second oblique hole, or the central axis of the fourth oblique hole and the central axis of the second oblique hole form an angle of 115~135° to form a turning hole of the second oblique hole.
2. The stacked SCR flue gas denitrification mixing device according to claim 1, characterized in that: In each column of the first inclined holes, the number of first inclined holes is equal; in each column of the second inclined holes, the number of second inclined holes is equal.
3. The stacked SCR flue gas denitrification mixing device according to claim 1 or 2, characterized in that: On the first flow mixing layer, all the first oblique holes are arranged in a matrix, and all the second oblique holes are arranged in a matrix; on the second flow mixing layer, all the third oblique holes are arranged in a matrix, and all the fourth oblique holes are arranged in a matrix.
4. The stacked SCR flue gas denitrification mixing device according to claim 1 or 2, characterized in that: The cross-sections of the first and second inclined holes are square.
5. An installation structure for a stacked SCR flue gas denitrification mixing device according to any one of claims 1-4, wherein a first horizontal flue, a first corner transition flue, a vertical flue, a second corner transition flue, and a second horizontal flue are sequentially provided between the economizer and the SCR flue gas denitrification device, characterized in that: The stacked SCR flue gas denitrification mixing device is installed in the first horizontal flue, and the first guiding mixing layer covers the flow section of the first horizontal flue; the direction from the first guiding mixing layer to the second guiding mixing layer is consistent with the flue gas flow direction.
6. The installation structure according to claim 5, characterized in that: The angle between the axis of the first inclined hole and the direction of flue gas flow is equal to the angle between the axis of the second inclined hole and the direction of flue gas flow.
7. The mounting structure according to claim 5 or 6, characterized in that: The angle between the axis of the first inclined hole and the direction of flue gas flow is 30°, and the angle between the axis of the second inclined hole and the direction of flue gas flow is 30°.
8. The mounting structure according to claim 5 or 6, characterized in that: The central axis of the third inclined hole forms a 120° angle with the central axis of the first inclined hole, thus forming a turning hole for the first inclined hole; the central axis of the fourth inclined hole forms a 120° angle with the central axis of the second inclined hole, thus forming a turning hole for the second inclined hole.
9. The mounting structure according to claim 5 or 6, characterized in that: A first arc-shaped guide plate is provided at the first corner transition flue, and a second arc-shaped guide plate is provided at the second corner transition flue, and a vertical flue is provided with an ammonia injection grid. A first mixer is provided in the vertical flue downstream of the ammonia injection grid, and a second mixer is provided in the second horizontal flue.
10. The mounting structure according to claim 5 or 6, characterized in that: The second horizontal flue sidewall directly above the SCR flue gas denitrification device is an inclined structure with a downward slope, and parallel and spaced third guide plates are provided on the inclined structure.