Fuel assembly upper nozzle

Abstract

The application discloses a fuel assembly upper tube support, which 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 arranged obliquely relative to a horizontal plane. Each adjusting assembly comprises a fixing block, an adjusting piece, a sliding block and an elastic structure. The fixing block is fixedly installed on the upper seat body, the sliding block is movably connected with the sliding rail part and is correspondingly arranged with the fixing block, the adjusting piece is in transmission connection with the fixing block and is used for pushing the sliding block to move along the sliding rail part, and 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 in the guide sliding groove. The fuel assembly upper tube support can compensate for the shortage of the pressing force by installing the adjusting assembly on the upper seat body, simultaneously reduce the initial compression amount of the fuel assembly pressing spring of the whole core, and effectively reduce the bending risk of the fuel assembly caused by the excessive fuel assembly pressing force. Meanwhile, the adjusting assembly can also make the elastic structure be at different heights to meet different functional requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of reactor nuclear fuel, in particular to a fuel assembly upper nozzle. BACKGROUND

[0002] In the existing pressurized water reactor, in order to ensure the compaction of the fuel assembly, the initial compression amount of the compaction spring needs to be conservatively considered the compaction of the minimum height fuel assembly (i.e. new fuel assembly) under different irradiation growth conditions of the fuel assembly, so that the compaction force of the end-of-life fuel assembly is too conservative, which is easy to cause the bending problem of the fuel assembly. Under the condition that the assemblies in different regions grow differently, the uniformity of the compaction force of the fuel assemblies in each position cannot be guaranteed. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a fuel assembly upper nozzle.

[0004] The technical scheme adopted by the present application to solve the technical problem is: a fuel assembly upper nozzle is constructed, which comprises an upper nozzle body and a plurality of adjusting assemblies;

[0005] The upper nozzle body is provided with a sliding rail part and a guide sliding groove, and the sliding rail part is inclinedly arranged relative to the horizontal plane.

[0006] Each adjusting assembly comprises a fixing block, an adjusting piece, a sliding block and an elastic structure.

[0007] The fixing block is fixedly installed on the upper nozzle body, the sliding block is movably connected with the sliding rail part and is correspondingly arranged with the fixing block, the adjusting piece is drivingly connected with the fixing block and is used for pushing the sliding block to move along the sliding rail part, and 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 in the guide sliding groove.

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

[0009] In some embodiments, the first end of the elastic structure is connected with the sliding block through a fastener.

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

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

[0012] In some embodiments, the elastic structure comprises a top plate spring, a plurality of connecting plate springs stacked below the top plate spring, and a guide piece penetrating through the connecting plate springs and connected with the top plate spring, and an end of the guide piece away from the top plate spring is installed in the guide slot.

[0013] In some embodiments, each connecting plate spring is provided with a through hole for the guide piece to penetrate.

[0014] In some embodiments, the top plate spring and the connecting plate springs are both plate-shaped springs with bent plates.

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

[0016] In some embodiments, the adjusting piece is a screw, and the adjusting piece is threadedly connected with the fixed block.

[0017] The present application has the following beneficial effects: the fuel assembly upper nozzle compensates for the lack of compression force by installing an adjusting assembly on the upper nozzle body, and simultaneously reduces the initial compression amount of the fuel assembly compression spring in the whole core, which can effectively reduce the risk of fuel assembly bending caused by excessive fuel assembly compression force. Meanwhile, the adjusting assembly can also make the elastic structure at different heights to meet different functional needs. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present application, the present application will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0019] Figure 1 is a general structure diagram of the fuel assembly upper nozzle in some embodiments of the present application;

[0020] Figure 2 is a partial structure diagram of the fuel assembly upper nozzle in some embodiments of the present application;

[0021] Figure 3 is a structure diagram of the sliding block in some embodiments of the present application;

[0022] Figure 4 is a top view diagram of the sliding block in some embodiments of the present application. DETAILED DESCRIPTION

[0023] In order to make the technical features, objectives and effects of the present application clearer, the specific embodiments of the present application will be described in detail below. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "upper", "lower", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like are based on the directions or positional relationships shown in the drawings, constructed and operated in a particular direction, and are only for the convenience of describing the technical solutions, and cannot be understood as indicating that the devices or elements indicated must have a particular direction, therefore, it cannot be understood as a limitation on the present application.

[0024] It should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing", "setting" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. When an element is referred to as "on" or "below" another element, the element can be "directly" or "indirectly" above the other element, or there can be one or more intervening elements. The terms "first", "second", "third" and the like are only for the convenience of describing the technical solutions, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features, therefore, the features with "first", "second", "third" and the like can be explicitly or implicitly included one or more of the features. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] Reference Figures 1 to 4 The upper seat body 1 is provided with a sliding rail part 11 and a guide sliding groove 12, the sliding rail part 11 is inclinedly arranged relative to the horizontal plane, each adjusting assembly 2 comprises a fixed block 21, an adjusting piece 22, a sliding block 23 and an elastic structure 24. Each adjusting assembly 2 comprises a fixed block 21, an adjusting piece 22, a sliding block 23 and an elastic structure 24, the fixed block 21 is fixedly installed on the upper seat body 1, the sliding block 23 is movably connected with the sliding rail part 11 and is correspondingly arranged with the fixed block 21, the adjusting piece 22 is drivingly connected with the fixed block 21 and the adjusting piece 22 is used for pushing the sliding block 23 to move along the sliding rail part 11, the first end of the elastic structure 24 is fixedly connected with the sliding block 23, and the second end of the elastic structure 24 is movably connected in the guide sliding groove 12.

[0026] As Figure 1 And Figure 2As shown, the adjusting member 22 is a screw, which is threadedly connected to the fixed block 21. The end of the adjusting member 22 is in contact with the side face of the slider 23. Since the slide rail 11 is inclined relative to the horizontal plane, the slide rail 11 is specifically inclined upward along the moving direction of the adjusting member 22. When the adjusting member 22 is rotated, it pushes the slider 23 upward. At this time, the elastic structure 24 also moves upward, and the second end of the elastic structure 24 moves accordingly in the guide groove 12. 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 sits on the lower core plate, and the upper seat 1 presses on the fuel assembly clamping system. During operation, due to the different neutron injection rates in different areas and the different skeleton growth of the fuel assembly in different positions, the compression of the clamping system varies, resulting in significant differences in the clamping force. Since the growth of irradiated fuel assemblies is greater than that of newly loaded fuel assemblies, the installation of adjustment component 2 on the upper body 1 compensates for insufficient clamping force and reduces the initial compression of the fuel assembly clamping springs in the entire core. This effectively reduces the risk of fuel assembly bending caused by excessive clamping force. Furthermore, the adjustment component 2 allows the elastic structure 24 to be positioned at different heights to meet various functional requirements.

[0027] In this embodiment, there are four elastic structures 24, all of which are installed on the upper seat 1 to jointly adjust the overall height of the fuel assembly upper pipe seat, thus 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 can be a bolt. Figure 4 As shown, the slider 23 is provided with a receiving groove 233 for accommodating the first ends of multiple elastic structures 24, and the receiving groove 233 can position the first ends of the elastic structures 24.

[0029] In addition, such as Figure 3 As shown, the slider 23 is provided with a through groove 231 that matches the slide rail 11 and a connecting hole 232 that matches the fastener 26. The through groove 231 can be a T-groove. During assembly, the through groove 231 in the slider 23 is first connected to the slide rail 11, and then the fixing block 21 is placed in the corresponding position of the upper seat 1 and welded to limit the position of the fixing block 21. During operation, only the adjusting member 22 needs to be operated. The adjusting member 22 will push the slider 23 to the ideal position, that is, the reasonable position of the slider 23 is adjusted by pushing and lifting. Specifically, through the action of the adjusting member 22 and the slider 23, the elastic structure 24 can be freely raised from 2mm to 8mm. Thus, without disassembling the spring assembly, the height of the upper pipe seat of the fuel assembly can be changed by the feed of the adjusting member 22 to adapt to various types of fuel assemblies.

[0030] As shown in Figure 2 The elastic structure 24 comprises a top plate spring 241, a plurality of connecting plate springs 242 stacked below the top plate spring 241, and a guide 243 passing through the connecting plate springs 242 and connected with the top plate spring 241. The end of the guide 243 away from the top plate spring 241 is installed in the guide sliding groove 12. The top plate spring 241 is used to connect with other components of the fuel assembly. Each connecting plate spring 242 is provided with a through hole for the guide 243 to pass through. The guide 243 is fixedly connected with the top plate spring 241 or is an integrally formed component, so that the guide 243 can move with the top plate spring 241. The top plate spring 241 and the connecting plate springs 242 are both spring sheets with bent plates. The number of the connecting plate springs 242 is preferably three.

[0031] It can be understood that the above embodiments only express the preferred embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, any equivalent transformation and modification within the scope of the claims of the present application shall be within the scope of the claims of the present application.

Claims

1. A fuel assembly upper nozzle, characterized by, The upper seat body (1) and a plurality of adjusting assemblies (2) are included. The upper seat body (1) is provided with a slide rail part (11) and a guide sliding groove (12), and the slide rail part (11) is arranged obliquely relative to the horizontal plane. Each adjusting assembly (2) includes a fixed block (21), an adjusting part (22), a sliding block (23), and an elastic structure (24). The fixed block (21) is fixedly installed on the upper seat body (1), the sliding block (23) is movably connected with the slide rail part (11) and is correspondingly arranged with the fixed block (21), the adjusting part (22) is drivingly connected with the fixed block (21) and is used for pushing the sliding block (23) to move along the slide rail part (11), the first end of the elastic structure (24) is fixedly connected with the sliding block (23), and the second end of the elastic structure (24) is movably connected in the guide sliding groove (12). The elastic structure (24) includes a top plate spring (241), a plurality of connecting plate springs (242), and a guide part (243), the plurality of connecting plate springs (242) are stacked and arranged below the top plate spring (241), the guide part (243) is arranged through the plurality of connecting plate springs (242) and is connected with the top plate spring (241), and one end of the guide part (243) away from the top plate spring (241) is installed in the guide sliding groove (12). The adjusting part (22) is a screw rod, and the adjusting part (22) is threadedly connected with the fixed block (21).

2. The fuel assembly upend of claim 1, wherein, The number of the elastic structures (24) is four.

3. The fuel assembly upend of claim 1, wherein, The first end of the elastic structure (24) is connected with the sliding block (23) through a fastener (26).

4. The fuel assembly upper nozzle of Claim 3 wherein, The sliding block (23) is provided with a through groove (231) matched with the slide rail part (11) and a connecting hole (232) matched with the fastener (26).

5. The fuel assembly upend of claim 1, wherein, The sliding block (23) is provided with an accommodation groove (233) for accommodating the first end of the elastic structure (24).

6. The fuel assembly upend of claim 1, wherein, Each connecting plate spring (242) is provided with a communication hole for the guide part (243) to pass through.

7. The fuel assembly upend of claim 1, wherein, The top plate spring (241) and the plurality of connecting plate springs (242) are both spring sheets with bent plates.

8. The fuel assembly upend of claim 1, wherein, The number of the connecting plate springs (242) is three.

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