Fixed type related component pressing structure for nuclear reactor and assembling method of fixed type related component pressing structure

Abstract

The invention discloses a fixed type related component pressing structure for a nuclear reactor and an assembling method thereof, the fixed type related component pressing structure for the nuclear reactor is arranged between a reactor core upper plate and a fuel component upper pipe seat, and the fixed type related component pressing structure for the nuclear reactor comprises a supporting piece, a central cylinder, a pressing component and an elastic check ring. According to the fixed type related component pressing structure for the nuclear reactor, integrated machining of the center cylinder and the supporting piece is achieved through optimization of the assembling mode structure, segmented machining and welding are avoided, the manufacturing process is simplified, the size precision of the assembled center cylinder is improved, and the manufacturing cost is reduced. And the non-welding assembly mode among the center cylinder, the pressure spring and the elastic check ring can simplify the assembly process. In addition, the compression spring is limited in the containing cavity through the buckling type connection mode of the elastic check ring, and rapid assembly is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear reactors, and in particular to a fixed-type related component pressing structure for a nuclear reactor and an assembly method thereof. Background Art

[0002] The core-related components can be divided into control rod assemblies and fixed-type related components. The fixed-type related components can be divided into primary neutron source assemblies, secondary neutron source assemblies and choke plug assemblies according to their functions, and are composed of a clamping system and related functional rods (which can be divided into primary neutron source rods, secondary neutron source rods, choke plug rods, etc.).

[0003] The fixed related components of the prior art have two different compression methods: a built-in compression spring compression system and an external compression spring compression system. Figure 1 As shown, it is composed of a rod and a bracket (clamping system). The bracket is composed of a round head, a wing-shaped piece, a ring (spring seat), and a thrust spring (clamping spring). The round head is a hollow round shape. The round head is composed of an upper and lower part. The wing-shaped piece extends from the lower part of the round head and is formed integrally with the lower part of the round head. The upper and lower parts of the round head are fixed to the lower part of the round head by, for example, threading, welding, brazing or bonding. The wing-shaped piece is designed with a mounting system for mounting the rod and a supporting element for longitudinally abutting against the upper plate of the core of the nuclear reactor. The bracket (clamping system) supports it on the top seat of the nuclear fuel assembly through the ring (spring seat). The ring can be supported downward on the lower edge of the round head through the flange, so that it remains set in the central cavity of the round head. The thrust spring is set in the central cavity of the round head, with the lower part supported on the edge of the ring and the upper part abutting against the lower surface of the internal partition at the upper part of the round head.

[0004] The above-mentioned fixed-type related components need to be installed with springs and rings (spring seats) inside the round head center tube, so the round head center tube is processed in sections in the cavity section, and then welded and fixed after the springs and spring seats are installed. Since there is a supporting structure outside the round head center tube, welding is difficult, and welding will cause certain deformation of the structure. After welding, the straightness of the upper and lower parts of the round head center tube and the position tolerance of some dimensions cannot be guaranteed. In addition, the welding position of the round head center tube is located in the cylinder air cavity section, and there is a supporting structure outside, which makes welding difficult. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a fixed related component pressing structure for a nuclear reactor and an assembly method thereof.

[0006] The technical solution adopted by the present invention to solve the technical problem is: construct a fixed related component pressing structure for a nuclear reactor, which is installed between the core upper plate and the upper tube seat of the fuel assembly, and includes a support, a center tube, a pressing assembly and an elastic retaining ring;

[0007] The upper end surface of the support member abuts against the core upper plate, and the support member is integrally formed with the central tube;

[0008] The central tube is provided with a receiving cavity and a clamping groove, and the clamping groove is located at the lower part of the receiving cavity;

[0009] The clamping assembly comprises a clamping spring and a connector located below the clamping spring, wherein the clamping spring is installed in the accommodating cavity, a portion of the connector protrudes from the accommodating cavity, and a lower end surface of the connector abuts against a connecting plate of an upper tube seat of the fuel assembly;

[0010] The elastic retaining ring is installed in the positioning groove and is used to limit the position of the compression spring.

[0011] In some embodiments, the compression spring and the connecting body are an integral part, and the diameter of the connecting body is smaller than the diameter of the compression spring;

[0012] The elastic retaining ring abuts against the lower end surface of the compression spring.

[0013] In some embodiments, the connecting body is a support seat, and the support seat includes a base portion installed in the accommodating cavity and an extension portion protruding from the accommodating cavity, and the upper end surface of the base portion abuts against the lower end surface of the compression spring;

[0014] The elastic retaining ring abuts against the lower end surface of the base portion.

[0015] In some embodiments, a shielding portion is provided at the upper portion of the accommodating cavity, and the shielding portion abuts against the upper end surface of the compression spring.

[0016] In some embodiments, a connecting cavity communicating with the accommodating cavity is further provided in the central tube, and a hanging groove is provided in the connecting cavity.

[0017] In some embodiments, the elastic retaining ring is provided with two fastening holes.

[0018] In some embodiments, the elastic retaining ring is made of spring steel.

[0019] In some embodiments, the support member includes a main body and a plurality of support portions abutting against the core upper plate.

[0020] In some embodiments, the plurality of support portions are symmetrically arranged along the central axis of the central tube.

[0021] In this embodiment, an assembly method of a fixed-type compression structure of related components for a nuclear reactor is also constructed, which is based on the fixed-type compression structure of related components for a nuclear reactor and includes:

[0022] Install the compression spring into the accommodating cavity so that the upper end surface of the compression spring is in close contact with the shielding portion;

[0023] Using the tooling to compress the compression spring, so that the lower end surface of the compression spring is located above the clamping groove;

[0024] Use a clamp to clamp the fastening hole of the circlip and install the circlip into the positioning groove.

[0025] The implementation of the present invention has the following beneficial effects: the fixed-type related component clamping structure for the nuclear reactor realizes the integrated processing of the center tube and the support member through the optimization of the assembly method structure, avoids segmented processing and welding, simplifies the manufacturing process, improves the dimensional accuracy of the center tube after assembly, and the non-welding assembly method between the center tube, the clamping spring, and the elastic retaining ring can simplify the assembly process. In addition, the compression spring is confined in the accommodating cavity through the snap-on connection method of the elastic retaining ring, so that rapid assembly is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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:

[0027] Figure 1 It is a fixed related component of the built-in spring of the prior art;

[0028] Figure 2 is an application schematic diagram of a fixed-type related component compression structure for a nuclear reactor in some embodiments of the present invention;

[0029] Figure 3 It is a structural schematic diagram of a first embodiment of a fixed-type related component compression structure for a nuclear reactor in some embodiments of the present invention;

[0030] Figure 4 is a structural schematic diagram of a second embodiment of a fixed-type related component compression structure for a nuclear reactor in some embodiments of the present invention;

[0031] Figure 5 yes Figure 3 A schematic diagram of the structure of the clamping assembly;

[0032] Figure 6 It is a structural diagram of the elastic retaining ring. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] See also Figures 2 to 6 It is a fixed related component clamping structure for a nuclear reactor in some embodiments of the present invention. The clamping structure can be used to fix and connect functional rods, which are used to be inserted into the guide tubes of the fuel assemblies to achieve different functions. The clamping structure includes a support 1, a center tube 2, a clamping assembly 3 and an elastic retaining ring 4.

[0036] like Figure 2 As shown, the upper end surface of the support member 1 abuts against the core upper plate 5, and the support member 1 is formed integrally with the center tube 2. There is no welding process, which improves the dimensional accuracy of the center tube 2 after assembly. At the same time, the welding process is avoided, which simplifies the manufacturing process of the fixed-related component clamping structure for the nuclear reactor and reduces the processing difficulty.

[0037] In addition, the central tube 2 is provided with a receiving cavity 21 and a positioning groove 22, and the positioning groove 22 is located at the lower part of the receiving cavity 21; the clamping assembly 3 includes a clamping spring 31 and a connecting body 32 located below the clamping spring 31, the clamping spring 31 is installed in the receiving cavity 21, a part of the connecting body 32 protrudes from the receiving cavity 21, and the lower end surface of the connecting body 32 abuts against the connecting plate of the upper tube seat 6 of the fuel assembly; the elastic retaining ring 4 is installed in the positioning groove 22, and is used to limit the position of the clamping spring 31, so that the clamping spring 31 can only move in the receiving cavity 21. Among them, the positioning groove 22 is an annular groove.

[0038] It can be understood that when the fixed-type related component clamping structure for a nuclear reactor is working, the upper end face of the support member 1 contacts the core upper plate 5, and the lower end face of the connector 32 contacts the connecting plate of the upper tube seat 6 of the fuel assembly. When the nuclear reactor is running, as the fuel assembly grows under irradiation, the gap between the upper plate 5 of the core and the upper tube seat 6 of the fuel assembly gradually decreases, and the connector 32 is pressed upward by an external force to press the clamping spring 31, and the upper end face of the support member 1 always keeps in contact with the upper plate 5 of the core, so that the support member 1 and the center tube 2 are always in a static state relative to the upper plate 5 of the core, thereby realizing the clamping and fixing function of the fixed-type related component clamping structure for a nuclear reactor. When the fixed-type related component clamping structure for a nuclear reactor is installed in the nuclear reactor, the clamping spring 31 is out of contact with the elastic retaining ring 4, and the elastic retaining ring 4 is always in a state of being free of force during the entire operation process. The maximum force on the circlip 4 comes from the contact state with the clamping assembly 3 after assembly, and the maximum force on the circlip 4 comes from the spring compression force of the clamping spring 31 at the beginning of its life. Since the circlip 4 is always in a stress-free state during operation, the risk of failure of the circlip 4 is extremely low.

[0039] The fixed-type compression structure of the relevant components used in the nuclear reactor realizes the integrated processing of the center tube 2 and the support member 1 through the optimization of the assembly method structure, avoids segmented processing and welding, simplifies the manufacturing process, improves the dimensional accuracy of the center tube 2 after assembly, and the non-welding assembly method between the center tube 2, the compression spring 31, and the elastic retaining ring 4 can simplify the assembly process. In addition, the compression spring is confined in the accommodating cavity 21 through the snap-on connection method of the elastic retaining ring 4, so as to realize rapid assembly.

[0040] Furthermore, the support member 1 includes a main body 11 and a plurality of support portions 12 abutting against the core upper plate 5, and the plurality of support portions 12 are symmetrically arranged along the central axis of the central tube 2. It can be understood that the support of the clamping structure on the core upper plate 5 is achieved through the support portions 12, and the provision of the plurality of support portions 12 can ensure the positioning stability of the clamping structure.

[0041] In this embodiment, the pressing assembly 3 has two structural modes, such as Figure 3 and Figure 5As shown, the first composition mode is that the compression spring 31 and the connecting body 32 are an integral part, the diameter of the connecting body 32 is smaller than the diameter of the compression spring 31, and the elastic retaining ring 4 abuts against the lower end surface of the compression spring 31. There is a step surface formed by the change of the outer diameter between the compression spring 31 and the connecting body 32. It can be understood that the compression assembly 3 adopts the upper and lower sections of the integral part, which simplifies the manufacturing process of the compression assembly 3, reduces the processing difficulty, and improves the assembly efficiency.

[0042] like Figure 4 As shown, the second structural mode of the clamping assembly 3 is that the connecting body 32 is a support seat, and the support seat includes a base portion 321 installed in the accommodating cavity 21 and an extension portion 322 protruding from the accommodating cavity 21, the upper end surface of the base portion 321 abuts against the lower end surface of the clamping spring 31, and the elastic retaining ring 4 abuts against the lower end surface of the base portion 321. The non-welding assembly of the clamping spring 31 and the spring seat can be realized, and the upper and lower integrated processing of the center tube 2 can also be realized, which simplifies the manufacturing process of the fixed-type related component clamping structure for the nuclear reactor, avoids deformation caused by welding, and improves the product size tolerance requirements.

[0043] Furthermore, a shielding portion 211 is provided at the upper portion of the accommodating chamber 21, and the shielding portion 211 abuts against the upper end surface of the compression spring 31. When the compression spring 31 is inserted into the accommodating chamber 21, the upper end of the compression spring 31 abuts against the shielding portion 211. The shielding portion 211 prevents the compression spring 31 from moving upward, so that the compression spring 31 is restricted in the accommodating chamber 21 for expansion and contraction, thereby preventing the compression spring 31 from escaping from the accommodating chamber 21.

[0044] like Figure 3 and Figure 4 As shown, the central tube 2 is further provided with a connecting cavity 23 connected to the accommodating cavity 21, and a hoisting groove 231 is provided in the connecting cavity 23. The hoisting groove 231 can cooperate with a hoisting tool so that the hoisting tool can hoist and move the clamping structure. The size of the hoisting groove 231 can be designed according to the hoisting tool used to hoist the control rod of the nuclear reactor.

[0045] like Figure 6 As shown, the circlip 4 is provided with two fastening holes 41. Specifically, the circlip 4 is an open annular structure, and two fastening holes 41 are designed at both ends of the opening. The two fastening holes 41 are clamped by a clamp to bring the two ends of the opening of the circlip 4 close together, so that the circlip 4 can be contracted and the outer diameter can be reduced so that it can be inserted into the center tube 2. After the clamp is released, the circlip 4 is restored to its initial state by elasticity.

[0046] Preferably, the elastic retaining ring 4 is made of spring steel, so that the shear stress of the elastic retaining ring 4 under the maximum stress state is much smaller than the material strength, thereby ensuring the stability of the elastic retaining ring 4 in use.

[0047] In this embodiment, an assembly method of a fixed-type related component clamping structure for a nuclear reactor is also constructed, which is based on the above-mentioned fixed-type related component clamping structure for a nuclear reactor, and includes: installing the clamping spring 31 into the accommodating cavity 21, so that the upper end surface of the clamping spring 31 is close to the shielding portion 211; using a tool to compress the clamping spring 31, so that the lower end surface of the clamping spring 31 is located above the locking groove 22; using a clamp to clamp the fastening hole 41 of the elastic retaining ring 4, and installing the elastic retaining ring 4 into the locking groove 22.

[0048] More specifically, when assembling the fixed-type related component compression structure for the nuclear reactor, first install the compression spring 31 into the accommodating cavity 21 at the lower part of the center tube 2, and the upper end surface of the compression spring 31 is close to the upper end surface of the accommodating cavity 21. The compression spring 31 can be compressed upward by using a tool, so that the lower end surface of the compression spring 31 is located above the clamping groove 22, and the position of the compression spring 31 is fixed by using a tool. Then, the two fastening holes 41 of the elastic retaining ring 4 are clamped by a clamp to shrink the diameter of the elastic retaining ring 4 so that its diameter is slightly smaller than the inner diameter of the accommodating cavity 21. After the elastic retaining ring 4 is placed into the clamping groove 22 along the bottom of the center tube 2, the elastic retaining ring 4 is slowly released to allow the elastic retaining ring 4 to rebound naturally and be clamped into the clamping groove 22, thereby completing the assembly of the fixed-type related component compression structure for the nuclear reactor.

[0049] 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 fixed related component pressing structure for a nuclear reactor, installed between a core upper plate (5) and a fuel assembly upper tube seat (6), characterized in that: It comprises a support member (1), a center tube (2), a clamping assembly (3) and an elastic retaining ring (4); The upper end surface of the support member (1) abuts against the core upper plate (5), and the support member (1) and the central tube (2) are integrally formed; The central tube (2) is provided with a receiving cavity (21) and a clamping groove (22), wherein the clamping groove (22) is located at the lower part of the receiving cavity (21); The clamping assembly (3) comprises a clamping spring (31) and a connecting body (32) located below the clamping spring (31), the clamping spring (31) being installed in the accommodating cavity (21), a portion of the connecting body (32) protruding from the accommodating cavity (21), and a lower end surface of the connecting body (32) abutting against a connecting plate of an upper tube seat (6) of the fuel assembly; The elastic retaining ring (4) is installed in the positioning groove (22) and is used to limit the position of the compression spring (31).

2. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The compression spring (31) and the connecting body (32) are an integral part, and the diameter of the connecting body (32) is smaller than the diameter of the compression spring (31); The elastic retaining ring (4) abuts against the lower end surface of the compression spring (31).

3. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The connecting body (32) is a support seat, comprising a base portion (321) installed in the accommodating cavity (21) and an extension portion (322) protruding from the accommodating cavity (21), and an upper end surface of the base portion (321) abuts against a lower end surface of the compression spring (31); The elastic retaining ring (4) abuts against the lower end surface of the base portion (321).

4. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: A shielding portion (211) is provided at the upper portion of the accommodating cavity (21), and the shielding portion (211) abuts against the upper end surface of the compression spring (31).

5. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The central tube (2) is also provided with a connecting cavity (23) communicating with the accommodating cavity (21), and a hanging groove (231) is provided in the connecting cavity (23).

6. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The elastic retaining ring (4) is provided with two fastening holes (41).

7. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The elastic retaining ring (4) is made of spring steel.

8. The fixed related component pressing structure for a nuclear reactor according to claim 1, characterized in that: The support member (1) comprises a main body portion (11) and a plurality of support portions (12) abutting against the core upper plate (5).

9. The fixed related component pressing structure for a nuclear reactor according to claim 8, characterized in that: The plurality of support portions (12) are arranged symmetrically and spaced apart from each other along the central axis of the central tube (2).

10. An assembly method of a fixed-type related component pressing structure for a nuclear reactor, based on the fixed-type related component pressing structure for a nuclear reactor according to any one of claims 1 to 9, characterized in that: include: Installing the compression spring (31) into the accommodating cavity (21) so that the upper end surface of the compression spring (31) is in close contact with the shielding portion (211); Using a tool to compress the compression spring (31) so that the lower end surface of the compression spring (31) is located above the locking groove (22); The fixing hole (41) of the elastic retaining ring (4) is clamped by a clamp, and the elastic retaining ring (4) is installed into the clamping groove (22).

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