A boiler wall sealing device for a thermal power plant

Abstract

This invention provides a boiler wall sealing device for thermal power plants, comprising multiple sets of tube panel assemblies. Adjacent tube panel assemblies are detachably connected via a snap-fit ​​structure, and their sealing is ensured through a snap-fit ​​connection. When the unit's operating load is stable, the snap-fit ​​structure remains tightly engaged, forming a seal and preventing air leakage. When load changes cause expansion displacement deviations in the tube panel assemblies, the snap-fit ​​structure can slide relative to each other, offsetting the expansion displacement deviations, maintaining the sealing effect, and ensuring that the effective expansion of the tube panels is not restricted. This device not only achieves effective sealing between tube panels to prevent air leakage, but also adapts to expansion displacements caused by temperature changes during operation, avoiding excessive stress due to restricted expansion of the tube panels that could lead to tube deformation, bending, or cracking, thus improving boiler operating safety and efficiency.

Description

Technical Field

[0001] This invention relates to the field of thermal power generation technology, and in particular to a boiler wall sealing device for thermal power plants. Background Technology

[0002] Currently, the boilers of existing large thermal power plants (especially pulverized coal boilers) have boiler walls composed of a large number of densely arranged tube screen structures. In actual operation, due to the differences in flue gas temperature, medium (water, steam) temperature and flow rate in different areas of the tube screen structure (such as furnace water-cooled walls, superheaters, reheaters, etc.), the thermal expansion of each tube screen and even individual tubes is not consistent, resulting in expansion displacement deviation.

[0003] Traditional rigid welded sealing structures restrict the natural and effective thermal expansion of tube panels when heated, and cannot adapt to dynamic displacement deviations between tube panels. The expansion force has nowhere to be released, which will accumulate into huge thermal stress inside the tube panels, supporting structures and seals. Under the action of this alternating stress for a long time, it is easy to cause weld cracking or seal tearing, thus forming gaps between tube panels and air leakage. The leakage of cold air will reduce the furnace temperature, disrupt the combustion aerodynamic field, increase flue gas heat loss, and ultimately lead to a significant decrease in boiler thermal efficiency. Tube panels near the air leakage point may generate excessive local thermal stress due to abnormal cooling, which will aggravate material fatigue and may even lead to tube deformation, bending or even cracking, weld fatigue cracking, and instability of the overall tube panel structure. This not only reduces the economic efficiency of unit operation, but also creates hidden dangers of tube rupture.

[0004] In view of the above reasons, the present invention proposes a boiler wall sealing device for thermal power plants to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a boiler wall sealing device for thermal power plants, which can ensure effective sealing between tube panels while fully adapting to the non-uniform expansion displacement caused by temperature changes during operation, thereby protecting the safety of the tube panel structure and ensuring the long-term efficient and stable operation of the boiler.

[0006] This invention provides a boiler wall sealing device for thermal power plants, comprising: multiple sets of tube screen assemblies, each tube screen assembly having a fastening structure on both sides, adjacent tube screen assemblies being detachably spliced ​​together through the fastening structure, and multiple sets of tube screen assemblies being spliced ​​end to end in sequence to form a boiler wall that seals the boiler.

[0007] Preferably, the interlocking structure is a snap-fit ​​fin, and the snap-fit ​​fins of adjacent tube panel assemblies are tightly engaged to seal the boiler.

[0008] Preferably, when a load change causes an expansion displacement deviation between adjacent tube screen assemblies, the interlocking fins between adjacent tube screen assemblies can slide relative to each other.

[0009] Preferably, the tube-screen assembly includes multiple sets of convection tubes and a screen plate welded between the busbars of adjacent convection tubes.

[0010] Preferably, the average diameter of each convection tube in adjacent tube-screen assemblies is different.

[0011] Preferably, the number of convection tubes in each group of the tube screen assembly is 3 to 5.

[0012] Preferably, the axes of the convection tubes are coplanar after adjacent tube screen components are spliced ​​together.

[0013] Preferably, the snap-back fins are welded to the tube screen assembly.

[0014] Preferably, the cross-section of the snap-back fin includes a zigzag segment and a snap-back segment connected thereto, and the end of the zigzag segment away from the snap-back segment is welded to the tube screen assembly.

[0015] Preferably, the broken line segment has a two-segment structure, with the first segment perpendicular to the axis of the tube screen assembly, and the second segment connected to the first segment at an obtuse angle. The backing segment is horizontally J-shaped, and the straight segment of the backing segment is arranged parallel to the first segment of the broken line segment.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting a snap-fit ​​structure between adjacent pipe panel components to make them detachable, the two sets of snap-fit ​​structures mesh with each other when the unit is operating under stable load, forming a seal to prevent air leakage, without losing the sealing function compared to the original structure. 2. Since the interlocking structure has a certain degree of freedom in the connected state, when the load changes, the different temperatures of the medium inside the pipe panel cause different expansion of the pipes, resulting in expansion displacement deviation. The interlocking seals slide against each other to offset the expansion difference between the pipe panel components. While maintaining the sealing function of the original sealing structure, it also avoids deformation, bending or even cracking of the pipe panel components due to different expansion amounts, thus avoiding pipe leakage and shutdown accidents. 3. Extend the service life of the tube panel components to ensure the safety and efficiency of boiler operation. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a three-dimensional structural schematic diagram of the boiler furnace wall sealing device of the present invention; Figure 2 This is a top view schematic diagram of the boiler furnace wall sealing device of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the fastening structure in the device of the present invention; Explanation of reference numerals in the attached figures: 1: Tube screen assembly; 101: Convection tube; 102: Screen panel; 2: Fastening structure; 201: Folded line segment; 202: Retractable segment. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 limiting this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figure 1-2 As shown, the present invention provides a boiler wall sealing device for thermal power plants, comprising: multiple sets of tube screen assemblies 1, each set of tube screen assemblies 1 having a fastening structure 2 on both sides, and adjacent tube screen assemblies 1 being able to be detachably spliced ​​together by means of the fastening structure 2, thereby allowing multiple sets of tube screen assemblies 1 to be spliced ​​end to end to surround the outside of the boiler equipment, forming a furnace wall that seals the boiler.

[0023] Specifically, the tube panel assembly 1 includes multiple sets of convection tubes 101 and screen plates 102 welded between the busbars of adjacent convection tubes 101. Each screen plate 102 and convection tube 101 are integrally formed from a high-temperature resistant and corrosion-resistant alloy material. To adapt to temperature changes in different areas of the boiler, the average diameter of each convection tube 101 in each adjacent tube panel assembly 1 is different. The number of convection tubes 101 in each tube panel assembly 1 is 3 to 5. The axis of each convection tube 101 in the same tube panel assembly 1 is coplanar with the central axis of the screen plate 102, and the axes of each convection tube 101 are coplanar after adjacent tube panel assemblies 1 are spliced, ensuring the sealing performance of adjacent tube panel assemblies 1 after splicing.

[0024] In this embodiment, the interlocking structure 2 is a snap-fit ​​fin, which is welded to the tube panel assembly 1. The snap-fit ​​fins of adjacent tube panel assemblies 1 are tightly engaged to seal the boiler and ensure the airtightness of the boiler wall. When load changes cause expansion displacement deviation between adjacent tube panel assemblies 1, the snap-fit ​​fins of the interlocking seal between adjacent tube panel assemblies 1 can slide relative to each other to offset the expansion difference between the tube panel assemblies 1. While maintaining the sealing function of the original sealing structure, it also avoids deformation, bending, or even cracking of the tube panel assembly due to different expansion amounts, thus preventing tube leakage and shutdown accidents.

[0025] like Figure 3 As shown, the cross-section of the snap-back fin includes a broken line segment 201 and a snap-back segment 202 connected thereto. The end of the broken line segment 201 away from the snap-back segment 202 is welded to the tube panel assembly 201.

[0026] The broken line segment 201 has a two-section structure. Its first section is perpendicular to the axis of the tube panel assembly 1, and its second section is connected to the first section at an obtuse angle. This allows it to avoid interference with the snap-back segment 202 during installation. The second section slides into the snap-back segment 202 of another fastening structure 2, resulting in a tight connection. The snap-back segment 202 is horizontally J-shaped, with its straight section parallel to the first section of the broken line segment 201. The openings of the snap-back segments 202 of adjacent tube panel assemblies 1 are opposite, allowing for a proper connection. The interlocking structure 2 is made of metal with a certain deformation capacity. When the load change causes expansion displacement deviation between adjacent tube panel components 1, the interlocking section 202 can deform to a certain extent according to the load direction change, ensuring that the interlocking structure 2 between adjacent tube panel components 1 can slide relative to each other, offsetting the expansion difference between tube panel components 1. This can achieve effective sealing between tube panels to prevent air leakage, and can also adapt to the expansion displacement caused by temperature changes during operation, avoiding excessive stress on the tube panel expansion that could lead to tube deformation, bending, or cracking, thus improving the safety and efficiency of boiler operation.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A boiler furnace wall sealing device for thermal power plants, characterized in that, include: Multiple sets of tube screen components are provided, with fastening structures on both sides of each tube screen component. Adjacent tube screen components can be detachably spliced ​​together through the fastening structures. Multiple sets of tube screen components are spliced ​​together end to end to form a furnace wall that seals the boiler.

2. The boiler wall sealing device for thermal power plants according to claim 1, characterized in that, The interlocking structure is a snap-fit ​​fin, and the snap-fit ​​fins of adjacent tube panel assemblies are tightly engaged to seal the boiler.

3. The boiler wall sealing device for thermal power plants according to claim 2, characterized in that, When load changes cause expansion displacement deviation between adjacent tube screen assemblies, the interlocking fins between adjacent tube screen assemblies can slide relative to each other.

4. The boiler wall sealing device for thermal power plants according to claim 1, characterized in that, The tube-screen assembly includes multiple sets of convection tubes and a screen plate welded between the busbars of adjacent convection tubes.

5. The boiler wall sealing device for thermal power plants according to claim 4, characterized in that, The average diameter of each convection tube in adjacent tube-screen assemblies is different.

6. The boiler wall sealing device for thermal power plants according to claim 4, characterized in that, The number of convection tubes in each group of the tube screen assembly is 3 to 5.

7. The boiler wall sealing device for thermal power plants according to claim 4, characterized in that, When adjacent tube screen components are spliced ​​together, the axes of each convection tube are coplanar.

8. The boiler wall sealing device for thermal power plants according to claim 2, characterized in that, The snap-back fins are welded to the tube screen assembly.

9. The boiler wall sealing device for thermal power plants according to claim 2, characterized in that, The cross-section of the snap-back fin includes a broken line segment and a snap-back segment connected thereto, and the end of the broken line segment away from the snap-back segment is welded to the tube screen assembly.

10. The boiler wall sealing device for thermal power plants according to claim 9, characterized in that, The broken line segment has a two-segment structure. The first segment is perpendicular to the axis of the tube screen assembly, and the second segment is connected to the first segment at an obtuse angle. The backing segment is a horizontally placed J-shape, and the straight segment of the backing segment is arranged parallel to the first segment of the broken line segment.

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