Fuel rod clamping ring and fuel assembly support grid

Abstract

The application discloses a fuel rod clamping ring and a fuel assembly support grid. The fuel rod clamping ring can be arranged in the support grid to clamp a fuel rod inserted in the support grid. The fuel rod clamping ring comprises a clamping ring body, a plurality of clamping portions protruding from the clamping ring body to clamp the fuel rod inserted in the clamping ring body, and a plurality of connecting portions arranged on the clamping ring body and connected to the support grid. The clamping portions of the fuel rod clamping ring protrude from the clamping ring body, which is beneficial to forming stable surface contact between the clamping portions and the fuel rod and reducing local abrasion of the surface of the fuel rod by the clamping portions. The clamping ring can be put into the support grid as a whole, and only the connecting portions need to be connected to the support grid, so that the clamping ring is easy to process and assemble.

Description

Technical Field

[0001] This invention relates to the field of fuel assembly technology, and in particular to a fuel rod clamping ring and a fuel assembly support grid. Background Technology

[0002] In the existing technical solution, the positioning grid is assembled from 32 inner strips with spring plates and rigid protrusions and 4 outer strips. The material of the inner strips is recrystallized Zr-4. The rigid protrusions on the inner strips are directly stamped on the inner strips; the spring plates are shaped like hairpins, and after being clamped onto the inner strips, they are fixed to the inner strips by spot welding. The solution is relatively complex.

[0003] Furthermore, in this technical solution, the spring plates and rigid protrusions of the clamping components are prone to loosening during operation within the reactor, causing the grid's clamping effect on the fuel rods to degrade. The contact area between the spring plates and rigid protrusions and the fuel rods is small, making them susceptible to abrasion between the clamping components and the fuel rods. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address at least one defect of the related technologies mentioned in the background: the contact area between the spring sheet and the rigid protrusion and the fuel rod is small, which easily leads to abrasion between the clamping components and the fuel rod. The present invention provides a fuel rod clamping ring and a fuel assembly support grid.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a fuel rod clamping ring, which can be disposed in a support grid to clamp the fuel rod inserted in the support grid; the fuel rod clamping ring includes a clamping ring body, a plurality of clamping parts protruding from the clamping ring body to clamp the fuel rod passing through it, and a plurality of connecting parts disposed on the clamping ring body and connected to the support grid.

[0006] Preferably, in the fuel rod clamping ring of the present invention, the clamping ring includes a plurality of bent pieces, each of the bent pieces includes an arc-shaped body, and the plurality of arc-shaped bodies are spliced ​​together to form the clamping ring body.

[0007] Preferably, in the fuel rod clamping ring of the present invention, each of the bent pieces further includes a clamping portion and a welding portion; the clamping portion protrudes from the arc-shaped body and is disposed at one end or the middle of the arc-shaped body; the welding portion is disposed on both sides of the arc-shaped body; the welding portions of two adjacent bent pieces are connected and fixed.

[0008] Preferably, in the fuel rod clamping ring of the present invention, the connecting portion includes two interconnected welded portions.

[0009] Preferably, in the fuel rod clamping ring of the present invention, the clamping portion is formed by punching on the bent sheet.

[0010] Preferably, in the fuel rod clamping ring of the present invention, a gap is left between adjacent clamping portions.

[0011] The present invention also discloses a fuel assembly support grid, comprising:

[0012] A supporting grid body, wherein the supporting grid body is provided with a plurality of grid elements, and a plurality of mounting parts are provided within each grid element; and

[0013] The fuel rod clamping ring described in any of the above embodiments, wherein the connecting portion of the fuel rod clamping ring cooperates with the mounting portion to connect the fuel rod clamping ring and the support grid body.

[0014] Preferably, in the fuel assembly support grid of the present invention, the support grid body includes a plurality of strips, which are interlaced to form a plurality of grid elements;

[0015] Each strip is provided with several mounting portions, and two adjacent mounting portions on the same strip fall into two adjacent grid cells respectively so that the clamping ring is in interference fit with the strip.

[0016] Preferably, in the fuel assembly support grid of the present invention, the mounting portion extends from the inside of the strip along the side wall of the strip to one end of the strip; the connecting portion of the clamping ring slides into the mounting portion along the outer end of the mounting portion.

[0017] Preferably, in the fuel assembly support grid of the present invention, the mounting portion is a protrusion formed by stamping the strip; the protrusion protrudes outward from the outside of the grid element.

[0018] Preferably, in the fuel assembly support grid of the present invention, a mechanical triangular structure is formed between adjacent mounting portions and strips within the same grid cell; a triangular support structure is formed between the clamping ring connected to the adjacent mounting portions and the strip.

[0019] By implementing this invention, the following beneficial effects are achieved:

[0020] The clamping part of the fuel rod clamping ring of the present invention protrudes from the clamping ring body, which is conducive to forming a stable surface contact between the clamping part and the fuel rod and can reduce the local abrasion of the fuel rod surface by the clamping part; the clamping ring can be inserted into the support grid as a whole, and only the connecting part needs to be connected to the support grid, which is easy to process and assemble. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0022] Figure 1This is one of the overall structural schematic diagrams of the fuel rod clamping ring according to an embodiment of the present invention;

[0023] Figure 2 This is a second schematic diagram of the overall structure of the fuel rod clamping ring according to an embodiment of the present invention;

[0024] Figure 3 This is the third schematic diagram of the overall structure of the fuel rod clamping ring according to an embodiment of the present invention;

[0025] Figure 4 This is the present invention. Figure 1 A schematic diagram of the structure of the bent sheet in the middle;

[0026] Figure 5 This is a partial schematic diagram of the overall structure of a fuel assembly support grid according to an embodiment of the present invention;

[0027] Figure 6 This is the present invention. Figure 5 An enlarged structural diagram of the supporting grid body of a cell in the lower right corner;

[0028] Figure 7 This is a schematic diagram of the interference fit between the mounting part and the clamping ring of the present invention;

[0029] Figure 8 This is a schematic diagram of the mechanical triangular structure of the fuel assembly support grid of the present invention. Detailed Implementation

[0030] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0032] In the description of the invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., 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 with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a chemical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] See Figures 1 to 4 An embodiment of the present invention discloses a fuel rod clamping ring, which can be disposed in a support grid to clamp fuel rods inserted in the support grid; the fuel rod clamping ring includes a clamping ring body 11, a plurality of clamping portions 132 protruding from the clamping ring body 11 to clamp fuel rods inserted therethrough, and a plurality of connecting portions 12 disposed on the clamping ring body 11 and connected to the support grid.

[0035] The clamping surface of the fuel rod clamping ring of the present invention is annular, and the entire clamping surface matches the fuel rod. The clamping surface is in close contact with the fuel rod, which helps to reduce the resistance of the clamping part 132 to the fluid. The clamping part 132 protrudes from the clamping ring body 11, which helps to form a stable surface contact between the clamping part 132 and the fuel rod, and can reduce the local abrasion of the fuel rod surface by the clamping part 132.

[0036] Furthermore, the clamping ring can be inserted into the body (2) of the support grid as a whole, and only the connecting part 12 needs to be connected to the body (2) of the support grid, which is easy to process and assemble.

[0037] Specifically:

[0038] See Figures 1 to 3 Clamping rings have various structural forms. Several common structural forms are listed below, such as... Figure 1 As shown, the clamping part 132 may be provided in the middle of the clamping ring body 11, and the connecting part 12 may be provided on the outer periphery of the clamping ring body 11; as Figure 2 As shown, the clamping part 132 may be provided at one end of the clamping ring body 11, and the connecting part 12 is provided on the outer periphery of the clamping ring; as Figure 3 As shown, the clamping portion 132 can also be located in the middle of the clamping ring body 11, and the connecting portion 12 is located on the outer periphery of the clamping ring body 11 and disconnects from the outer periphery of the clamping portion 132. Preferably, the axial height of the clamping ring is lower than the axial height of the support grid. It should be noted that the side of the clamping portion 132 near the center of the clamping ring body 11 is an arc surface, which enables a stable surface contact between the clamping ring and the fuel rod, thereby reducing local abrasion of the fuel rod surface by the clamping components and better clamping the fuel rod.

[0039] like Figure 1 and Figure 4 As shown, the clamping ring includes several bent pieces 13, each of which includes an arc-shaped body 131. Multiple arc-shaped bodies 131 are joined together to form the clamping ring body 11. The bent pieces 13 are connected and fixed to form the clamping ring. In some other embodiments, the clamping ring body 11 can be an integral structure, with a connecting part 12 welded to the outside of the clamping ring body 11, and a clamping part 132 stamped on the clamping ring body 11. Since the clamping ring body 11 is formed by joining multiple arc-shaped bodies 131 of the bent pieces 13, it can be understood that the clamping ring body 11 is formed by joining multiple arc-shaped surfaces. This facilitates a tighter fit between the clamping ring and the outer surface of the fuel rod, thereby improving the clamping of the fuel rod.

[0040] Furthermore, such as Figure 4 As shown, each bent piece 13 further includes a clamping portion 132 and a welding portion 133; the clamping portion 132 protrudes from the arc-shaped body 131 and is located at one end or the middle of the arc-shaped body 131; the welding portion 133 is located on both sides of the arc-shaped body 131; the welding portions 133 of two adjacent bent pieces 13 are connected and fixed. Preferably, the connecting portion 12 includes two interconnected welding portions 133, that is, the welding portions 133 of two adjacent bent pieces 13 are connected and fixed to form the connecting portion 12. The welding method can be spot welding or brazing.

[0041] Furthermore, the clamping part 132 is punched on the bending piece 13, and a gap is left between adjacent clamping parts 132 to facilitate heat dissipation.

[0042] Compared with the spring-loaded rigid convex clamping system, the fuel rod clamping ring of this invention has a more compact design, which helps to reduce the height of the support grid, reduce flow resistance, and reduce neutron absorbing material.

[0043] See Figures 5 to 7 One embodiment of the present invention discloses a fuel assembly support grid, which includes a support grid body and a fuel rod clamping ring as described in any of the above embodiments. The support grid body 2 has a plurality of grid elements, each grid element having a plurality of mounting portions 211. The connecting portion 12 of the fuel rod clamping ring cooperates with the mounting portions 211 to connect the fuel rod clamping ring to the support grid body 2, thereby installing the fuel rod clamping ring within the grid element. It should be noted that... Figure 5 The example only shows a portion of the structure of the fuel assembly support grid; the specific number of cells in the support grid is not limited.

[0044] The fuel assembly support grid of the present invention only requires a number of mounting parts 211 to be provided on the support grid body (2) to install the fuel rod 3 clamping ring to achieve the clamping of the fuel rod 3. The clamping ring and the support grid body (2) are processed separately. After the clamping ring is processed, it is directly placed into the support grid body (2). Its structural design is simple and easy to process and assemble. Moreover, the clamping surface of the fuel rod 3 clamping ring is annular, and the entire clamping surface matches the fuel rod 3. The clamping ring is close to the fuel rod 3, which helps to reduce the resistance of the clamping part 132 to the fluid. The clamping part 132 protrudes from the clamping ring body 11, which helps the clamping part 132 to form a stable surface contact with the fuel rod 3, and can reduce the local abrasion of the fuel rod 3 surface by the clamping part 132.

[0045] Specifically:

[0046] like Figures 5 to 7 As shown, the support grid body 2 includes several strips 21, which are connected in an interlaced manner to form several grid elements; each strip 21 is provided with several mounting parts 211 for mounting clamping rings, and two adjacent mounting parts 211 fall into two adjacent grid elements respectively so that the clamping rings are interference-fitted with the strips.

[0047] Strip 21 has a simple structure with no windows and few protrusions, which helps reduce the flow resistance of strip 21. For example... Figure 7 The diagram shown illustrates the interference fit between the mounting part 211 and the connecting part 12. Please refer to the diagram for further details. Figure 5 When two clamping rings are inserted into two adjacent mounting portions 211 on the strip 21, the two mounting portions 211 can restrain each other, balance the force, and reduce the stress on the strip to prevent deformation and breakage. Preferably, each strip 21 falling within the range of each grid cell has a mounting portion 211 corresponding to that grid cell, and one grid cell includes four strips 21, that is, one grid cell has four corresponding mounting portions 211. In some embodiments, the strips 21 are fixed together by welding. It should be noted that the mounting portion 211 corresponding to each grid cell protrudes away from the center of that grid cell, so as to Figure 7 Taking the topmost strip 21 of the grid cell as an example, the mounting portion 211 on the left protrudes away from the center of the grid cell, while the mounting portion 211 on the right protrudes close to the center of the grid cell. Therefore, on the strip 21, only the mounting portion 211 on the left is the mounting portion 211 corresponding to the grid cell.

[0048] See Figure 6The mounting portion 211 extends from the inside of the strip 21 along the side wall of the strip 21 to one end of the strip 21; the connecting portion 12 of the clamping ring slides into the mounting portion 211 along its outer end. Preferably, the mounting portion 211 is a groove with one open end, and the connecting portion 12 is inserted into the mounting portion 211 from the open end and welded in place. In some embodiments, the open end of the mounting portion 211 is located at the lower part of the strip 21 under its own weight, and the connecting portion 12 is inserted from bottom to top and welded in place to prevent it from falling out under gravity.

[0049] Furthermore, such as Figure 6 and Figure 7 As shown, the mounting portion 211 is a protrusion formed by stamping the strip 21; the protrusion protrudes outward from the grid cell. The mounting portion 211 is stamped towards the outside of the grid cell it is located in. Two adjacent mounting portions 211 on each strip are arranged opposite each other and stamped in a staggered manner, and the openings of the protrusions face opposite directions. When the mounting portion 211 is connected to the connecting portion 12, the two adjacent grid cells are squeezed by the clamping rings, and the directions of the forces are opposite, so that the clamping rings are mutually constrained, preventing the clamping rings from detaching from the mounting portion 211 due to deformation of the strip 21.

[0050] like Figure 8 As shown, in the present invention, a mechanical triangular structure is formed between adjacent mounting portions 211 and strips 21 within the same grid cell of the support grid; a triangular support structure is formed between the clamping ring connected to the adjacent mounting portions 211 and the strips 21, which is beneficial to improving the buckling resistance of the support grid.

[0051] By implementing this invention, the following beneficial effects are achieved:

[0052] The clamping part of the fuel rod clamping ring of the present invention protrudes from the clamping ring body, which is conducive to forming a stable surface contact between the clamping part and the fuel rod and can reduce the local abrasion of the fuel rod surface by the clamping part; the clamping ring can be inserted into the support grid as a whole, and only the connecting part needs to be connected to the support grid, which is easy to process and assemble.

[0053] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that for those skilled in the art, the above embodiments or technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present invention. These all fall within the protection scope of the present invention. That is, the embodiments described "in some embodiments" can be freely combined with any of the embodiments above and below. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A fuel assembly support grid, characterized in that, include: The support grid body (2) is provided with a plurality of grid elements, and a plurality of mounting parts (211) are provided in the grid elements. and A fuel rod clamping ring may be disposed in a support grid to clamp fuel rods inserted in the support grid; the fuel rod clamping ring includes a clamping ring body (11), a plurality of clamping portions (132) protruding from the clamping ring body (11) to clamp the fuel rods passing through it, and a plurality of connecting portions (12) disposed on the clamping ring body (11) and connected to the support grid. The clamping ring includes several bent pieces (13), each of the bent pieces (13) includes an arc-shaped body (131), and multiple arc-shaped bodies (131) are spliced ​​together to form the clamping ring body (11). Each of the bent pieces (13) further includes a clamping part (132) and a welding part (133); the clamping part (132) protrudes from the arc-shaped body (131) and is located at one end or the middle of the arc-shaped body (131); the clamping part (132) is punched on the bent piece (13); the welding part (133) is located on both sides of the arc-shaped body (131); the welding parts (133) of two adjacent bent pieces (13) are connected and fixed. The connecting part (12) includes two interconnected welding parts (133); The connecting part (12) of the fuel rod clamping ring cooperates with the mounting part (211) to connect the fuel rod clamping ring and the support grid body (2). The supporting grid body (2) includes a plurality of strips (21), which are interlaced to form a plurality of grid elements; Each strip (21) is provided with a plurality of mounting portions (211). Two adjacent mounting portions (211) on the same strip fall into two adjacent grid cells respectively so that the clamping ring is in interference fit with the strip. The mounting portion (211) is a protrusion formed by stamping the strip (21). The protrusion protrudes out of the outside of the grid cell, and two adjacent mounting portions (211) on each strip are staggered and opposite to each other, and the openings of the protrusions face opposite directions.

2. The fuel assembly support grid according to claim 1, characterized in that, The mounting portion (211) extends from the inside of the strip (21) along the side wall of the strip (21) to one end of the strip (21); the connecting portion (12) of the clamping ring slides into the mounting portion (211) along the outer end of the mounting portion (211).

3. The fuel assembly support grid according to claim 1 or 2, characterized in that, A mechanical triangular structure is formed between adjacent mounting portions (211) and strips (21) within the same grid cell; a triangular support structure is formed between the clamping ring connected to the adjacent mounting portions (211) and the strips (21).

4. The fuel assembly support grid according to claim 1, characterized in that, A gap is left between adjacent clamping parts (132).

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