Upper pipe seat of fuel assembly

Abstract

The invention discloses an upper pipe seat of a fuel assembly. The upper pipe seat comprises an upper seat body and a plurality of adjusting assemblies, the upper seat body is provided with a sliding rail part and a guide sliding groove, and the sliding rail part is obliquely arranged relative to the horizontal plane. Each adjusting assembly comprises a fixing block, an adjusting piece, a sliding block and an elastic structure. The fixed block is fixedly installed on the upper seat body, the sliding block is movably connected with the sliding rail part and corresponds to the fixed block, the adjusting piece is in transmission connection with the fixed block and used for pushing the sliding block to move along the sliding rail part, the first end of the elastic structure is fixedly connected with the sliding block, and the second end of the elastic structure is movably connected into the guide sliding groove. According to the fuel assembly upper tube base, the adjusting assembly is installed on the upper base body to compensate for the insufficient pressing force, meanwhile, the initial compression amount of a compression spring of a full-reactor-core fuel assembly is reduced, and the fuel assembly bending risk caused by the too large pressing force of the fuel assembly can be effectively reduced. Meanwhile, due to the arrangement of the adjusting assembly, the elastic structure can be located at different heights so as to meet different functional requirements.

Description

Technical Field

[0001] The invention relates to the field of reactor nuclear fuel, in particular to an upper tube seat of a fuel assembly. Background Art

[0002] In existing pressurized water reactors, in order to ensure the compression of fuel assemblies under different irradiation growth conditions, the initial compression amount of the compression spring needs to be conservative to consider the compression of the fuel assembly with the smallest height (i.e., the new fuel assembly). Therefore, the compression force on the fuel assembly at the end of its life is too conservative, which easily leads to the problem of fuel assembly bending. In the case of different irradiation growth of assemblies in different areas, the uniformity of the compression force of fuel assemblies at various positions cannot be guaranteed. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an upper tube socket for a fuel assembly.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing an upper tube seat of a fuel assembly, which includes an upper seat body and a plurality of adjustment assemblies;

[0005] The upper seat body is provided with a slide rail portion and a guide slide groove, and the slide rail portion is arranged inclined relative to the horizontal plane;

[0006] Each of the adjustment components includes a fixed block, an adjustment member, a sliding block and an elastic structure;

[0007] The fixed block is fixedly mounted on the upper seat body, the sliding block is movably connected to the slide rail portion and is arranged corresponding to the fixed block, the adjusting member is transmission-connected to the fixed block and the adjusting member is used to push the sliding block to move along the slide rail portion, the first end of the elastic structure is fixedly connected to the sliding block, and the second end of the elastic structure is movably connected in the guide groove.

[0008] In some embodiments, the number of the elastic structures is four.

[0009] In some embodiments, the first end of the elastic structure is connected to the slider via a fastener.

[0010] In some embodiments, the sliding block is provided with a through groove matching the sliding rail portion and a connecting hole matching the fastener.

[0011] In some embodiments, the sliding block is provided with a receiving groove for receiving the first end of the elastic structure.

[0012] In some embodiments, the elastic structure includes a top leaf spring, a plurality of connecting leaf springs and a guide member, wherein the plurality of connecting leaf springs are stacked and located below the top leaf spring, the guide member is passed through the plurality of connecting leaf springs and connected to the top leaf spring, and one end of the guide member away from the top leaf spring is installed in the guide groove.

[0013] In some embodiments, each of the connecting plate springs is provided with a connecting hole for the guide member to pass through.

[0014] In some embodiments, the top leaf spring and the plurality of connecting leaf springs are all bent plate-shaped spring sheets.

[0015] In some embodiments, the number of the connecting leaf springs is three.

[0016] In some embodiments, the adjusting member is a screw, and the adjusting member is threadedly connected to the fixing block.

[0017] The implementation of the present invention has the following beneficial effects: the upper tube seat of the fuel assembly compensates for the lack of clamping force by installing an adjustment component on the upper seat body, while reducing the initial compression of the clamping spring of the entire core fuel assembly, which can effectively reduce the risk of fuel assembly bending caused by excessive clamping force of the fuel assembly. At the same time, the setting of the adjustment component can also make the elastic structure at different heights to meet different functional requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 is a schematic diagram of the overall structure of the upper tube seat of the fuel assembly in some embodiments of the present invention;

[0020] Figure 2 is a partial structural schematic diagram of an upper tube seat of a fuel assembly in some embodiments of the present invention;

[0021] Figure 3 is a schematic diagram of the structure of a slider in some embodiments of the present invention;

[0022] Figure 4 Schematic diagram of a top view of a slider in some embodiments of the present invention. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0024] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0025] See also Figures 1 to 4 , is a fuel assembly upper tube seat in some embodiments of the present invention, which includes an upper seat body 1 and a plurality of adjustment assemblies 2. A slide rail portion 11 and a guide slide groove 12 are provided on the upper seat body 1, and the slide rail portion 11 is arranged tilted relative to the horizontal plane. Each adjustment assembly 2 includes a fixed block 21, an adjustment member 22, a slider 23 and an elastic structure 24. Each adjustment assembly 2 includes a fixed block 21, an adjustment member 22, a slider 23 and an elastic structure 24. The fixed block 21 is fixedly mounted on the upper seat body 1, the slider 23 is movably connected to the slide rail portion 11 and is arranged corresponding to the fixed block 21, the adjustment member 22 is transmission-connected to the fixed block 21 and the adjustment member 22 is used to push the slider 23 to move along the slide rail portion 11, the first end of the elastic structure 24 is fixedly connected to the slider 23, and the second end of the elastic structure 24 is movably connected in the guide slide groove 12.

[0026] like Figure 1 and Figure 2As shown, the adjusting member 22 is a screw rod, and the adjusting member 22 is threadedly connected to the fixed block 21. The end of the adjusting member 22 fits the side end surface of the slider 23. Since the slide rail portion 11 is tilted relative to the horizontal plane, the slide rail portion 11 is specifically tilted upward along the moving direction of the adjusting member 22. When the adjusting member 22 is rotated, the adjusting member 22 pushes the slider 23 to move upward, and the elastic structure 24 also moves upward, and the second end of the elastic structure 24 also moves in the guide slot 12 accordingly. As the elastic structure 24 moves upward, the overall height of the upper tube seat of the fuel assembly is also adjusted. It can be understood that in a pressurized water reactor, the lower tube seat of the fuel assembly is located on the lower core plate, and the upper seat body 1 is pressed on the fuel assembly clamping system. During operation, due to different neutron injections in different areas, the skeleton growth of fuel assemblies at different positions is different, which leads to differences in the compression of the clamping system, resulting in large differences in the clamping force. Since the growth of the fuel assembly after irradiation is greater than that of the newly loaded fuel assembly, the adjustment assembly 2 is installed on the upper seat body 1 to compensate for the lack of pressing force and reduce the initial compression of the full core fuel assembly pressing spring, which can effectively reduce the risk of fuel assembly bending caused by excessive fuel assembly pressing force. At the same time, the setting of the adjustment assembly 2 can also make the elastic structure 24 at different heights to meet different functional requirements.

[0027] In this embodiment, there are four elastic structures 24 , which are all mounted on the upper seat body 1 to jointly adjust the overall height of the upper tube seat of the fuel assembly, thereby ensuring the stability of the adjustment.

[0028] The first end of the elastic structure 24 is connected to the slider 23 via a fastener 26, which may be a bolt. Figure 4 As shown, the slider 23 is provided with a receiving groove 233 for receiving the first ends of the plurality of elastic structures 24 , and the receiving groove 233 can position the first ends of the elastic structures 24 .

[0029] In addition, if Figure 3 As shown, the slider 23 is provided with a through slot 231 matching the slide rail portion 11 and a connection hole 232 matching the fastener 26. The through slot 231 can be a T-slot. During assembly, the through slot 231 in the slider 23 is first docked with the slide rail portion 11, and then the fixed block 21 is placed in the corresponding position of the upper seat body 1 for electric welding to limit the position of the fixed block 21. During operation, it is only necessary to operate the adjusting member 22, and the adjusting member 22 will push the slider 23 to the ideal position, that is, the slider 23 is adjusted to a reasonable position by pushing and lifting. Specifically, the elastic structure 24 can be freely raised by 2mm to 8mm through the action of the adjusting member 22 and the slider 23, so that the height of the upper tube seat of the fuel assembly can be changed by feeding the adjusting member 22 without disassembling the spring assembly to adapt to various types of fuel assemblies.

[0030] like Figure 2 As shown, the elastic structure 24 includes a top leaf spring 241, a plurality of connecting leaf springs 242 and a guide member 243. The plurality of connecting leaf springs 242 are stacked and located below the top leaf spring 241. The guide member 243 is inserted through the plurality of connecting leaf springs 242 and connected to the top leaf spring 241. The end of the guide member 243 away from the top leaf spring 241 is installed in the guide slot 12. The top leaf spring 241 can be used to connect with other components of the fuel assembly, and each connecting leaf spring 242 is provided with a connecting hole for the guide member 243 to penetrate. The guide member 243 can be fixedly connected to the top leaf spring 241 or be an integrally formed component so that the guide member 243 can move with the top leaf spring 241. The top leaf spring 241 and the plurality of connecting leaf springs 242 are all spring sheets with bent plates. The number of the connecting leaf springs 242 is preferably three.

[0031] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. A fuel assembly upper tube socket, characterized in that: It comprises an upper seat body (1) and a plurality of adjustment components (2); The upper seat body (1) is provided with a slide rail portion (11) and a guide slide groove (12), and the slide rail portion (11) is arranged to be inclined relative to a horizontal plane; Each of the adjustment components (2) comprises a fixed block (21), an adjustment member (22), a sliding block (23) and an elastic structure (24); The fixed block (21) is fixedly mounted on the upper seat body (1); the sliding block (23) is movably connected to the slide rail portion (11) and is arranged corresponding to the fixed block (21); the adjusting member (22) is transmission-connected to the fixed block (21) and the adjusting member (22) is used to push the sliding block (23) to move along the slide rail portion (11); the first end of the elastic structure (24) is fixedly connected to the sliding block (23), and the second end of the elastic structure (24) is movably connected to the guide slide groove (12).

2. The fuel assembly top tube socket according to claim 1, characterized in that: The number of the elastic structures (24) is four.

3. The fuel assembly top socket according to claim 1, characterized in that: The first end of the elastic structure (24) is connected to the slider (23) via a fastener (26).

4. The fuel assembly top socket according to claim 3, characterized in that: The sliding block (23) is provided with a through groove (231) matching the sliding rail portion (11) and a connecting hole (232) matching the fastener (26).

5. The fuel assembly top socket according to claim 1, characterized in that: The sliding block (23) is provided with a receiving groove (233) for receiving the first end of the elastic structure (24).

6. The fuel assembly top socket according to claim 1, characterized in that: The elastic structure (24) comprises a top leaf spring (241), a plurality of connecting leaf springs (242) and a guide member (243); the plurality of connecting leaf springs (242) are stacked and located below the top leaf spring (241); the guide member (243) is passed through the plurality of connecting leaf springs (242) and connected to the top leaf spring (241); and one end of the guide member (243) away from the top leaf spring (241) is installed in the guide slot (12).

7. The fuel assembly top socket according to claim 6, characterized in that: Each of the connecting plate springs (242) is provided with a connecting hole for the guide member (243) to pass through.

8. The top tube socket of the fuel assembly according to claim 6, characterized in that: The top leaf spring (241) and the plurality of connecting leaf springs (242) are all bent plate-shaped spring sheets.

9. The fuel assembly top socket according to claim 6, characterized in that: The number of the connecting plate springs (242) is three.

10. The fuel assembly top socket according to claim 1, characterized in that: The adjusting member (22) is a screw rod, and the adjusting member (22) is threadedly connected to the fixing block (21).

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