A guide tube connecting tube, upper tube seat and fuel assembly skeleton

Abstract

The present invention belongs to the technical field of reactor fuel assemblies, and specifically relates to a guide tube connecting tube, an upper tube seat and a fuel assembly skeleton. The guide tube connecting tube of the present invention is a hollow cylinder with open upper and lower end faces, and its inner diameter matches the outer diameter of the guide tube. The lower part of the guide tube connecting tube is expanded and connected to the outside of the guide tube, and the upper part of the guide tube connecting tube is provided with a plurality of protrusions along the circumferential direction; the upper tube seat of the present invention includes a clamping spring and a tube seat, and a plurality of slide grooves are provided at the inner wall of the channel where the tube seat needs to be connected to the guide tube, a spring is provided at the end of the slide groove, a block is connected in front of the spring, and a depression is provided under the block in the slide groove. The present invention has a simple structure, is easy to install, and effectively overcomes the problem that the connection mechanism between the guide tube and the upper tube seat in the prior art is easy to loosen, and significantly improves the safety and reliability of the fuel assembly.

Description

Technical Field

[0001] The invention belongs to the technical field of reactor fuel assemblies, and in particular relates to a guide tube connecting tube, an upper tube seat and a fuel assembly skeleton. Background Art

[0002] The fuel assembly is generally composed of an upper tube seat, a lower tube seat, a spacer grid, a guide tube and a fuel rod. The fuel assembly is located in the middle of the reactor chamber. The coolant passes through the core and flows through the fuel rods to take away the reaction heat.

[0003] The guide tube is an important structural component of the fuel assembly, which provides an insertion channel for the control rod and the neutron source rod. Usually, multiple guide tubes are arranged in a fuel assembly, and the upper end of the guide tube is connected to the upper tube seat, and the lower end of the guide tube is connected to the lower tube seat.

[0004] like Figure 1 , Figure 2 As shown, in the prior art, the connecting assembly between the guide tube and the upper tube seat includes an expansion structure 2 and a connection structure 3: the expansion structure 2 is nested inside the upper tube seat 1, that is, it is expanded and fixed inside the upper tube seat 1; the upper end of the connection structure 3 is connected to the expansion structure 2, and the lower end is nested outside the guide tube 4 to achieve the connection between the guide tube 4 and the upper tube seat 1. The technical defects of this connection design are: complex structure, difficult installation, easy loosening, and serious impact on the safety and reliability of the fuel assembly. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the connection structure between the guide tube and the upper tube seat in the prior art is complex, difficult to install, and easy to loosen.

[0006] The technical solution of the present invention is as follows:

[0007] A guide tube connecting pipe is a hollow cylinder with open upper and lower end faces, whose inner diameter matches the outer diameter of the guide tube. The lower part of the guide tube connecting pipe is expanded and connected to the outside of the guide tube, and the upper part of the guide tube connecting pipe is provided with a plurality of protrusions along the circumferential direction.

[0008] As a preferred solution: the guide tube connecting tube is evenly provided with 2 or 3 protrusions along the circumferential direction.

[0009] As a preferred solution: the protrusion of the guide tube connecting tube is in a rectangular parallelepiped or cylindrical shape.

[0010] An upper pipe seat includes a compression spring and a pipe seat, wherein the compression spring is fixed on the top of the pipe seat. A plurality of slide grooves are arranged at the inner wall of the hole where the pipe seat needs to be connected to the guide pipe, the starting end of the slide groove is located at the hole opening of the lower end face of the pipe seat, and the end of the slide groove is closed inside the pipe seat; a spring is arranged at the end of the slide groove, a block is connected in front of the spring, and a depression is arranged under the block of the slide groove; the number and width of the slide grooves match the protrusion of the guide pipe connecting pipe.

[0011] A guide tube connecting tube with a guide tube expanded at the lower part has its protrusion inserted into the upper tube seat along the slide groove of the upper tube seat; during this process, the protrusion of the guide tube connecting tube first presses the blocking block toward the spring and falls into the depression below the blocking block; thereafter, the blocking block returns to its original position under the action of the spring and blocks the protrusion that falls into the depression.

[0012] A fuel assembly skeleton includes a guide tube, a positioning grid, an upper tube seat and a lower tube seat. A plurality of guide tubes are inserted into a grid element of the positioning grid from top to bottom. The upper end of the guide tube is fixedly connected to the upper tube seat, and the lower end of the guide tube is fixedly connected to the lower tube seat. The upper tube seat adopts the upper tube seat of the above-mentioned design structure; any one of the above-mentioned guide tube connecting tubes is used to connect the guide tube and the upper tube seat; the grid element of the positioning grid is a four-sided cylinder, and upper slots are respectively provided on the four faces of the grid element for matching with plug-in plug-in, and the plug-in includes a clamping portion and a plug-in portion.

[0013] As a preferred solution: the plug-in is an angle plug-in, which includes a clamping portion and two plug-in portions, wherein the two plug-in portions are perpendicular to each other, and the clamping portion is arranged between the two plug-in portions.

[0014] As a preferred solution: the plug-in is an edge plug-in, which includes two clamping parts and three plug-in parts, the three plug-in parts are in a T shape, and the clamping parts are respectively arranged at a right angle between every two plug-in parts.

[0015] As a preferred solution: the plug-in is a channel plug-in, which includes three clamping parts and four plug-in parts, the four plug-in parts are in a cross shape, and the clamping part is arranged between every two plug-in parts.

[0016] As a preferred solution: the plug-in is an intermediate plug-in, which includes four clamping parts and four plug-in parts, the four plug-in parts are in a cross shape, and the clamping part is arranged between every two plug-in parts.

[0017] The beneficial effects of the present invention are:

[0018] (1) The guide tube connecting tube and the upper tube seat matched therewith of the present invention have simple structure and convenient installation, and effectively overcome the problem that the connection mechanism between the guide tube and the upper tube seat in the prior art is easy to loosen, thereby significantly improving the safety and reliability of the fuel assembly;

[0019] (2) The design of the positioning grid of the fuel assembly skeleton of the present invention is not only applicable to common rod-shaped fuel assemblies, but also to fuel elements with a larger outer diameter, such as annular fuel elements, so that the coolant and the fuel element can be more fully contacted, the fuel element can be horizontally positioned, and a certain stirring effect can be produced on the coolant;

[0020] (3) The fuel assembly skeleton of the present invention uses plug-ins to clamp and support the fuel elements, which significantly enhances the overall rigidity and simplifies the processing procedures of the support parts of the positioning grid, thereby reducing the processing difficulty;

[0021] (4) In the fuel assembly skeleton of the present invention, a gap is provided between the side surface of the plug-in plug-in portion and the side surface of the grid element, so that the clamping force value range of the clamping portion is increased, which can meet the working requirements under different conditions;

[0022] (5) The fuel assembly skeleton of the present invention can avoid the problem of welding dissimilar materials when the grid element and the plug-in are made of different materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the connection relationship between the guide tube and the upper tube seat in the prior art;

[0024] Figure 2 for Figure 1 A partial enlarged view of

[0025] Figure 3 This is a schematic diagram of a guide pipe connecting pipe structure of the present invention;

[0026] Figure 4 It is a schematic diagram of the tube base structure of an upper tube base of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the spacer grid in the fuel assembly skeleton of the present invention;

[0028] Figure 6 For angular plugin intention;

[0029] Figure 7 This is a schematic diagram of the edge plug-in;

[0030] Figure 8 This is a schematic diagram of the intermediate plug-in.

[0031] In the figure, 1-upper tube seat, 2-expansion structure, 3-connection structure, 4-guide tube, 5-guide tube connecting tube, 6-protrusion, 7-slide groove, 8-spring, 9-block, 10-depression, 11-upper end surface of tube seat, 12-lower end surface of tube seat, 13-guide tube channel, 14-positioning grid element, 15-clamping part, 16-plug-in part, 17-corner plug-in, 18-side plug-in, 19-channel plug-in, 20-middle plug-in, 21-plug-in, 22-outer strip, 23-guide wing. DETAILED DESCRIPTION

[0032] The following is a detailed description of a guide tube connecting tube and an upper tube seat of the present invention in conjunction with the accompanying drawings and embodiments.

[0033] Example 1

[0034] like Figure 3 As shown, the guide tube connecting tube 5 in this embodiment is a hollow cylinder with open upper and lower end faces, whose inner diameter matches the outer diameter of the guide tube 4, and the lower part of the guide tube connecting tube 5 is expanded to the outside of the guide tube 4; the upper part of the guide tube connecting tube 5 is provided with a plurality of protrusions 6 along the circumferential direction.

[0035] like Figure 4 As shown, the upper tube seat 1 in this embodiment includes a compression spring 8 and a tube seat, and the compression spring 8 is fixed on the top of the tube seat. A plurality of slide grooves 7 are arranged at the inner wall of the channel where the tube seat needs to be connected to the guide tube 4, and the starting end of the slide groove 7 is located at the channel opening of the lower end face of the tube seat, and the end of the slide groove 7 is closed inside the tube seat; a spring 8 is arranged at the end of the slide groove 7, and a block 9 is connected in front of the spring 8, and a depression 10 is arranged under the block 9 of the slide groove 7; the number and width of the slide grooves 7 match the protrusion 6 of the guide tube connection tube 5.

[0036] The guide tube connecting tube 5 with the guide tube 4 expanded at the lower part has its protrusion 6 inserted into the upper tube seat 1 along the slide groove 7 of the upper tube seat 1; during this process, the protrusion 6 of the guide tube connecting tube 5 first presses the blocking block 9 toward the spring 8 and falls into the recess 10 below the blocking block 9; thereafter, the blocking block 9 returns to its original position under the action of the spring 8, blocking the protrusion 6 that falls into the recess 10, thereby realizing the fixed connection between the guide tube 4 and the upper tube seat 1.

[0037] Example 2

[0038] The guide tube connecting tube 5 in this embodiment is evenly provided with two or three protrusions 6 along the circumferential direction. The protrusions 6 may be in the shape of a cuboid or a cylinder.

[0039] Example 3

[0040] A fuel assembly skeleton in this embodiment includes a guide tube 4, a spacer grid, an upper tube seat 1 and a lower tube seat. A plurality of guide tubes 4 penetrate the grid element of the spacer grid from top to bottom. The upper end of the guide tube 4 is fixedly connected to the upper tube seat 1, and the lower end of the guide tube 4 is fixedly connected to the lower tube seat. The guide tube 4 and the upper tube seat 14 are connected using the guide tube and upper tube seat connection structure in any of the above embodiments. Figure 5-Figure 8 As shown, the grid element 14 of the spacer grid is a four-sided cylinder, and upper slots are respectively provided on the four faces of the grid element 14 for mating with the plug-in 21 . The plug-in 21 includes a clamping portion 15 and a plug-in portion 16 . The clamping portion 15 protrudes toward the inner side of the grid element 14 .

[0041] The plug-in 10 includes a corner plug-in 17, a side plug-in 18, a channel plug-in 19 and a middle plug-in 20. The corner plug-in 17 includes a clamping portion 15 and two plug-in portions 16, wherein the two plug-in portions 16 are perpendicular to each other, and the clamping portion 15 is arranged between the two plug-in portions 16. The side plug-in 18 includes two clamping portions 15 and three plug-in portions 16, wherein the three plug-in portions 16 are in a T-shape, and the clamping portions 15 are respectively arranged at right angles between every two plug-in portions 16. The channel plug-in 19 includes three clamping portions 15 and four plug-in portions 16, wherein the four plug-in portions 16 are in a cross shape, and the clamping portion 15 is arranged between every two plug-in portions 16. The middle plug-in 20 includes four clamping portions 15 and four plug-in portions 16, wherein the four plug-in portions 16 are in a cross shape, and the clamping portion 15 is arranged between every two plug-in portions 16.

Claims

1. A fuel assembly skeleton, comprising a guide tube (4), a positioning grid, an upper tube seat (1) and a lower tube seat, wherein a plurality of guide tubes (4) penetrate the grid element of the positioning grid from top to bottom, the upper end of the guide tube (4) is fixedly connected to the upper tube seat (1), the lower end of the guide tube (4) is fixedly connected to the lower tube seat, and the guide tube connecting tube connects the guide tube (4) and the upper tube seat (1); the guide tube connecting tube is a hollow cylinder with open upper and lower end faces, and its inner diameter matches the outer diameter of the guide tube (4); the lower part of the guide tube connecting tube (5) is expanded and connected to the outside of the guide tube (4), characterized in that: The guide tube connecting tube (5) is evenly provided with 2 or 3 protrusions (6) along the circumferential direction; the protrusions (6) of the guide tube connecting tube (5) are rectangular or cylindrical; the upper tube seat comprises a clamping spring and a tube seat, and the clamping spring is fixed above the tube seat; a plurality of slide grooves (7) are provided at the inner wall of the channel where the tube seat needs to be connected to the guide tube (4), the starting end of the slide groove (7) is located at the channel opening of the lower end face of the tube seat, and the end of the slide groove (7) is closed inside the tube seat; a spring (8) is provided at the end of the slide groove (7), a blocking block (9) is connected in front of the spring (8), and a depression (10) is provided below the blocking block (9) on the slide groove (7); the number and width of the slide grooves (7) are the same as those of the guide tube The projection (6) of the connecting tube (5) matches; the guide tube connecting tube (5) with the guide tube (4) is expanded at the lower part of the upper tube seat, and its projection (6) is inserted into the upper tube seat (1) along the slide groove (7) of the upper tube seat (1); in this process, the projection (6) of the guiding tube connecting tube (5) first presses the blocking block (9) toward the spring (8) and falls into the recess (10) below the blocking block (9); thereafter, the blocking block (9) returns to its original position under the action of the spring (8) and blocks the projection (6) falling into the recess (10); the grid element of the positioning grid is a four-sided cylinder, and upper slots are respectively provided on the four faces of the grid element for matching the plug-in plug-in, and the plug-in includes a clamping portion and a plug-in portion.

2. A fuel assembly skeleton according to claim 1, characterized in that: The plug-in unit is an angle plug-in unit, which comprises a clamping portion and two plug-in portions, wherein the two plug-in portions are perpendicular to each other, and the clamping portion is arranged between the two plug-in portions.

3. A fuel assembly skeleton according to claim 1, characterized in that: The plug-in is a side plug-in, which comprises two clamping parts and three plug-in parts, the three plug-in parts are in a T-shape, and the clamping parts are respectively arranged at right angles between every two plug-in parts.

4. A fuel assembly skeleton according to claim 1, characterized in that: The plug-in is a channel plug-in, which comprises three clamping parts and four plug-in parts. The four plug-in parts are in a cross shape, and the clamping part is arranged between every two plug-in parts.

5. A fuel assembly skeleton according to claim 1, characterized in that: The plug-in is a middle plug-in, which comprises four clamping parts and four plug-in parts. The four plug-in parts are in a cross shape, and the clamping part is arranged between every two plug-in parts.

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