Test piece clamping unit and multi-layer remountable irradiation test assembly

Abstract

The invention relates to the technical field of research reactor irradiation, and provides a test piece clamping unit and a multi-layer remountable irradiation test assembly, the clamping unit comprises an upper end clamping piece; the lower end clamping piece and the upper end clamping piece are symmetrically arranged and are completely the same in structure, the lower end clamping piece and the upper end clamping piece are each provided with a cooling channel and a plurality of first clamping blind holes used for clamping the end of a tested piece, and first elastic pieces used for providing radial pre-tightening force are arranged on the side walls of the first clamping blind holes; the bottom of the first clamping blind hole is provided with a second elastic piece used for providing axial pre-tightening force. One end of each pull rod penetrates through the upper end clamping piece, and the other end of each pull rod penetrates through the lower end clamping piece; the fixing rings are connected to the two ends of the pull rod and used for limiting the upper end clamping piece and the lower end clamping piece to be away from each other. According to the invention, the test pieces can be loaded in batches, and each test piece is ensured to have radial pretightening force and axial pretightening force.

Description

Technical Field

[0001] The present invention relates to the field of research reactor irradiation technology, and in particular to a test piece clamping unit and a multi-layer reinstallable irradiation test assembly. Background Art

[0002] Fuel elements are the smallest components of fuel assemblies. Before the fuel assemblies are used in engineering, they must be subjected to in-pile irradiation tests and performance tests to comprehensively evaluate their radiation resistance and provide key experimental data and performance verification basis for design and development. Depending on the stage of fuel assembly development, different levels of in-pile irradiation tests are required. Generally, the last step of verification is the component-level irradiation test to verify the structural strength, thermal performance, hydraulic performance, compatibility, operability, radiation resistance, corrosion resistance, etc. of the fuel assemblies, obtain reliable operation data, and provide a basis for engineering applications.

[0003] The irradiation test assembly is generally a scaled-down fuel assembly. In the research reactor, the fuel element is used as a test piece and needs to be clamped and fixed by a clamping unit to ensure the requirements of high temperature and high pressure, flow-induced vibration, flow velocity matching, etc. during the test. For example, the patent document with the publication number "CN110580961A" provides a clamping and fixing method for a rod-shaped test piece to meet the above requirements. However, this prior art can only be applied to the clamping and fixing of a single test piece, and cannot be applied to batch loading of test pieces. Summary of the invention

[0004] The object of the present invention is to provide a test piece clamping unit and a multi-layer reinstallable radiation test assembly to solve the above-mentioned defects of the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] A test piece clamping unit, comprising:

[0007] Upper clamping member;

[0008] The lower end clamping piece is symmetrically arranged with the upper end clamping piece and has the same structure. Both are provided with cooling channels and a plurality of first clamping blind holes for clamping the end of the test piece. The side walls of the first clamping blind holes are provided with first elastic pieces for providing radial preload, and the bottoms of the first clamping blind holes are provided with second elastic pieces for providing axial preload;

[0009] A plurality of pull rods, one end of which is passed through the upper clamping member, and the other end of which is passed through the lower clamping member; and

[0010] A plurality of fixing rings are connected to the two ends of the pull rod and are used to limit the upper clamping piece and the lower clamping piece from moving away from each other.

[0011] Optionally, the clamping unit also includes a plurality of intermediate clamping parts, the intermediate clamping parts are provided with clamping through holes at the positions corresponding to the first clamping blind holes or second clamping blind holes are provided at both ends, and at least one clamping through hole is provided on the intermediate clamping parts, the first elastic part is provided on the side walls of the clamping through hole and the second clamping blind hole, and the second elastic part is provided on the bottom of the second clamping blind hole.

[0012] Optionally, the first elastic member is a leaf spring, and the second elastic member is a disc spring.

[0013] Optionally, a gasket is provided at one end of the second elastic member contacting the test piece.

[0014] The present invention also provides a multi-layer reinstallable irradiation test assembly, comprising a clamping unit as described in any one of the above items, and also comprising a center rod, a lower tube seat and a locking component. The lower tube seat is fixedly connected to the lower end of the center rod, and the clamping unit is sequentially sleeved on the center rod and supported by the lower tube seat. The locking component is arranged at the upper end of the center rod for locking the clamping unit.

[0015] Optionally, mounting holes are provided in the centers of the upper clamping piece and the lower clamping piece, and the cross-section of the part of the center rod on which the clamping unit is sleeved is a polygonal structure perpendicular to the axis. The mounting hole can limit the rotation of the center rod and a gap is reserved as the cooling channel.

[0016] Optionally, the upper clamping piece and the lower clamping piece are provided with one or more holes near the edges as the cooling channel.

[0017] Optionally, the end of the mounting hole of the upper clamping member and / or the end of the mounting hole of the lower clamping member are provided with clips that fit with the side surfaces of the center rod.

[0018] Optionally, the locking component includes an upper tube seat, a lock core and a pressing seat; the portion of the central rod sleeved with the clamping unit is defined as a mounting section, a limiting boss is provided above the mounting section, a cross section of the limiting boss perpendicular to the axis is a polygonal structure, and the central rod is a bare rod section between the mounting section and the limiting boss;

[0019] The upper tube seat is sleeved on the mounting section and is provided with a supporting step for supporting the lock core. The distance between the limiting boss and the supporting step is equal to the length of the lock core. The lock core is provided with an inner hole that can cooperate with the limiting boss. After the lock core is inserted into the supporting step, it is rotated to a target angle so that the limiting boss limits the axial displacement of the lock core and the clamping unit.

[0020] The cross section of the lock core perpendicular to the axis is a polygonal structure, and a step anti-rotation hole is provided inside the clamping seat. The small diameter section of the step anti-rotation hole cooperates with the limiting boss, and the large diameter section of the step anti-rotation hole cooperates with the lock core.

[0021] Optionally, in each of the clamping units, a mixing plate is provided at the lower end of the lower end clamping piece.

[0022] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, the upper clamping part and the lower clamping part are supported by a pull rod, and after the two ends of the pull rod are connected to the fixing ring, the upper clamping part and the lower clamping part are restricted to move away from each other, and the two ends of the test piece are inserted into the first clamping blind holes on the upper clamping part and the lower clamping part, and each clamping unit can load multiple test pieces; at the same time, the first elastic part provides a radial preload force for the test piece to buffer radial vibration and impact load, and the second elastic part provides an axial preload force for the test piece to buffer axial vibration and impact load. It can be seen that compared with the prior art, the present invention can not only load test pieces in batches, but also ensure that each test piece has radial preload force and axial preload force. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore 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.

[0024] Figure 1 A front view of a test piece clamping unit provided in Example 1;

[0025] Figure 2 for Figure 1 AA section view;

[0026] Figure 3 The structure diagram of the upper clamping part Figure 1 ;

[0027] Figure 4 The structure diagram of the upper clamping part Figure 2 ;

[0028] Figure 5 A front view of a test piece clamping unit provided in Example 2;

[0029] Figure 6 for Figure 5 BB cross-sectional view;

[0030] Figure 7 is a top view of the intermediate clamping member;

[0031] Figure 8 for Figure 7 CC section view;

[0032] Fig. 9A front view of a multi-layer reinstallable irradiation test assembly provided in Example 3;

[0033] Fig.10 A cross-sectional view of a multi-layer reinstallable radiation test assembly provided in Example 3;

[0034] Fig.11 for Fig.10 The enlarged view of point D;

[0035] Fig.12 for Fig.11 EE cross-sectional view;

[0036] Fig.13 Front view of the center pole;

[0037] Fig.14 It is the front view of the upper tube seat;

[0038] Fig.15 for Fig.14 FF cross-sectional view;

[0039] Fig.16 It is the front view of the lock cylinder;

[0040] Fig.17 for Fig.16 GG cross-sectional view;

[0041] Fig.18 It is a structural schematic diagram of the pressing seat;

[0042] Fig.19 This is the main view of the mixing plate;

[0043] Icon: 100-short clamping unit, 150-long clamping unit, 101-lower clamping piece, 102-upper clamping piece, 1021-first clamping blind hole, 1022-mounting hole, 1023-first cooling channel, 1024-second cooling channel, 103-short pull rod, 104-long pull rod, 105-fixing ring, 106-first elastic piece, 107-second elastic piece, 108-middle clamping piece, 108 1- clamping through hole, 1082- second clamping blind hole, 109- clip, 200- center rod, 201- mounting section, 202- limiting boss, 300- lower tube seat, 400- locking component, 401- upper tube seat, 4011- supporting step, 402- lock core, 403- clamping seat, 4031- small diameter section, 4032- large diameter section, 500- mixing plate, 600- short test piece, 700- long test piece. DETAILED DESCRIPTION

[0044] Example 1

[0045] refer to Figure 1 and Figure 2This embodiment provides a test piece clamping unit, including an upper clamping piece 102 , a lower clamping piece 101 , a plurality of pull rods and a plurality of fixing rings 105 .

[0046] The upper clamping member 102 is arranged symmetrically with the upper clamping member and has the same structure. Figure 3 and Figure 4 Both are provided with cooling channels and a plurality of first clamping blind holes 1021 for clamping the ends of the test pieces. As an option, five first clamping blind holes 1021 are provided in this embodiment, that is, one clamping unit can clamp five test pieces.

[0047] Reference again Figure 2 The side wall of the first clamping blind hole 1021 is provided with a first elastic member 106, which provides radial preload for the test piece, realizes radial elastic support and positioning of the test piece, and is used to buffer radial vibration and impact load, and buffer flow-induced vibration of the test piece under the hydraulic flushing of the circuit. As an option, the first elastic member 106 of this embodiment selects a leaf spring, which can be divided into a straight leaf spring and a bent leaf spring according to the shape. This embodiment uses a bent leaf spring, which can be fixed by resistance welding or laser welding.

[0048] A second elastic member 107 is provided at the bottom of the first clamping blind hole 1021. The second elastic member 107 provides an axial preload for the test piece, and is used to buffer axial vibration and impact load, and buffer the flow-induced vibration of the test piece under the hydraulic flushing of the circuit. As an option, the second elastic member 107 of this embodiment is a disc spring. Furthermore, since the disc spring has a large stiffness, in order to prevent local point contact from causing damage to the end of the test piece, a gasket is provided at the end of the second elastic member 107 that contacts the test piece.

[0049] One end of the pull rod is inserted into the upper clamping member 102, and the other end is inserted into the lower clamping member 101. The fixing ring 105 is connected to both ends of the pull rod to limit the upper clamping member 102 and the lower clamping member 101 from moving away from each other. In this embodiment, the fixing ring 105 is connected to the pull rod by a thread. As an option, in this embodiment, three pull rods are provided in one clamping unit. The three pull rods and the corresponding fixing rings 105 jointly support the upper clamping member 102 and the lower clamping member 101. The space between the upper clamping member 102 and the lower clamping member 101 is used to load the test piece.

[0050] Example 2

[0051] refer to Figure 5-Figure 8In this embodiment, based on the first embodiment, the clamping unit further includes a plurality of intermediate clamping members 108. The intermediate clamping members 108 are provided with clamping through holes 1081 at positions corresponding to the first clamping blind holes 1021, or second clamping blind holes 1082 are provided at both ends of the positions corresponding to the first clamping blind holes 1021, and there is at least one clamping through hole 1081 on the intermediate clamping member 108. In this way, it is convenient to load two test pieces of different lengths, which are defined as short test pieces 600 and long test pieces 700 for the convenience of description. In the first embodiment, the intermediate clamping members 108 are not required, and the clamping unit is entirely loaded with short test pieces 600.

[0052] As an option, in one clamping unit of this embodiment, three intermediate clamping members 108 are further provided between the upper clamping member 102 and the lower clamping member 101, and two second clamping blind holes 1082 and three clamping through holes 1081 are provided on the intermediate clamping member 108. In this way, the clamping unit has four layers in total, three long test pieces 700 are provided between the upper clamping member 102 and the lower clamping member 101, and the three long test pieces 700 pass through the clamping through holes 1081 of the intermediate clamping member 108, and short test pieces 600 are loaded between the upper clamping member 102 and the adjacent intermediate clamping member 108, between the intermediate clamping member 108 and the adjacent intermediate clamping member 108, and between the lower clamping member 101 and the adjacent intermediate clamping member 108. In this embodiment, one clamping unit can load eight short test pieces 600 and three long test pieces 700.

[0053] Those skilled in the art should understand that the number of clamping through holes 1081 and second clamping blind holes 1082 on the intermediate clamping member 108 may also be changed according to actual conditions. For example, in some embodiments, all of the intermediate clamping member 108 are clamping through holes 1081, and all of the clamping units are used to load the long test piece 700.

[0054] Similarly, the side walls of the clamping through hole 1081 and the second clamping blind hole 1082 on the middle clamping member 108 are provided with a first elastic member 106, and the bottom of the second clamping blind hole 1082 is provided with a second elastic member 107. In actual application, the first elastic member 106 can be provided on the side walls at both ends of the clamping through hole 1081.

[0055] In addition, it is easy to understand that the lengths of the tie rods in Example 2 and Example 1 should be different. Specifically, the tie rod in Example 2 is longer than the tie rod in Example 1. For ease of understanding, the tie rod in Example 2 is defined as a long tie rod 104, and the tie rod in Example 1 is defined as a short tie rod 103.

[0056] Example 3

[0057] refer to Fig. 9 and Fig.10This embodiment provides a multi-layer reinstallable radiation test assembly, which includes a center rod 200, a lower tube seat 300 and a locking component 400 based on a plurality of clamping units.

[0058] As an option, this embodiment includes four clamping units provided in the first embodiment and one clamping unit provided in the second embodiment. For the convenience of description, the clamping unit provided in the first embodiment is defined as a short clamping unit 100, and the clamping unit provided in the second embodiment is defined as a long clamping unit 150. The four short clamping units 100 have four layers in total and are loaded with twenty short test pieces 600. The one long clamping unit 150 also has four layers and is loaded with eight short test pieces 600 and three long test pieces 700. Therefore, the test assembly provided in this embodiment has eight layers in total and is loaded with twenty-eight short test pieces 600 and three long test pieces 700. It should be understood that in other embodiments, of course, different numbers of clamping units provided in the above two embodiments can be selected according to the different numbers of short test pieces 600 and long test pieces 700 to be loaded, or different from the clamping units provided in the above two embodiments, all short test pieces 600 can be loaded, all long test pieces 700 can be loaded, or both types of test pieces can be loaded.

[0059] The lower tube seat 300 is fixedly connected (e.g., welded) to the lower end of the center rod 200, and the clamping units are sequentially sleeved on the center rod 200 and supported by the lower tube seat 300. For example, four short clamping units 100 are placed first, and then the long clamping unit 150 is placed. Of course, other orders of placement are also possible.

[0060] refer to Figure 3 , Figure 4 and Fig.12 In this embodiment, a mounting hole 1022 is provided in the center of the upper clamping member 102 and the lower clamping member 101. The section of the center rod 200 on which the clamping unit is mounted is a polygonal structure perpendicular to the axis. The mounting hole 1022 can limit the rotation of the center rod 200 and reserve a gap as a cooling channel. The section of the center rod 200 on which the clamping unit is mounted is defined as a mounting section 201. As an option, the section of the mounting section 201 in this embodiment that is perpendicular to the axis is a regular pentagonal structure. On this basis, the mounting hole 1022 in this embodiment includes five arcs, each of which is tangent to the corresponding side of the mounting section 201. In this way, the rotation of the center rod 200 is limited and a gap is left as a cooling channel.

[0061] Further, one or more holes are provided near the edges of the upper clamping member 102 and the lower clamping member 101 as cooling channels. For ease of understanding and description, the cooling channel at the center is defined as the first cooling channel 1023, and the cooling channel near the edge is defined as the second cooling channel 1024. As an option, two second cooling channels 1024 are provided in this embodiment. In addition, it should be understood that the middle clamping member 108 should also be provided with corresponding cooling channels.

[0062] In this embodiment, the end of the mounting hole 1022 of the upper clamping member 102 is provided with a clip 109 (such as Figure 4 As shown), it is easy to understand that the clips 109 have a certain elasticity, and all the clips 109 together hold the mounting section 201 of the center rod 200 and flexibly contact with the center rod 200 to reduce vibration.

[0063] The locking member 400 is disposed at the upper end of the center rod 200 and is used to lock the clamping unit. Fig.11 , Figure 13-Figure 18 In this embodiment, the locking component 400 includes an upper tube seat 401, a lock core 402 and a pressing seat 403. A limiting boss 202 is provided above the mounting section 201 of the center rod 200. The center rod 200 is a bare rod section between the mounting section 201 and the limiting boss 202.

[0064] The upper tube seat 401 is sleeved on the mounting section 201, that is, the upper tube seat 401 is provided with a hole that cooperates with the mounting section 201, and the interior of the upper tube seat 401 is provided with a supporting step 4011 for supporting the lock core 402, and the distance between the limiting boss 202 and the supporting step 4011 is equal to the length of the lock core 402, and the cross-section of the limiting boss 202 perpendicular to the axis is a polygonal structure (as an option, this embodiment is a regular pentagonal structure), and the interior of the lock core 402 is provided with an inner hole that can cooperate with the limiting boss 202. After the lock core 402 is inserted into the supporting step 4011, it is rotated to the target angle, and under the action of the limiting boss 202, the axial displacement of the lock core 402 and the clamping unit is limited.

[0065] The cross section of the lock core 402 perpendicular to the axis is also a polygonal structure (as an option, this embodiment is also a regular pentagonal structure), and a step anti-rotation hole is provided inside the pressing seat 403. The small diameter section 4031 of the step anti-rotation hole cooperates with the limiting boss 202, and the large diameter section 4032 of the step anti-rotation hole cooperates with the lock core 402. In this way, the pressing seat 403 cannot rotate relative to the center rod 200, and the lock core 402 cannot rotate relative to the pressing seat 403, thereby achieving a locking function. Furthermore, in actual applications, a locking nut (not shown) can also be provided on the pressing seat 403, and the locking nut is connected to the center rod 200 by threads, thereby limiting the axial position of the pressing seat 403.

[0066] In addition, it should be understood that the upper tube seat 401, the pressing seat 403 and the lower tube seat 300 should all be provided with corresponding holes as cooling channels.

[0067] In this embodiment, in each clamping unit, a mixing plate 500 is provided at the lower end of the lower clamping member 101. Fig.19 As shown, the mixing plate 500 of each clamping unit is provided with the same number of flow channels to redistribute the flow, ensure the consistency of the flow entering each clamping unit, stir the coolant between layers to reduce the cross flow caused by different cross sections, and reduce the lateral impact that the flow-induced vibration may cause to the test piece.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test piece clamping unit, characterized in that: include: Upper clamping member; The lower end clamping piece is symmetrically arranged with the upper end clamping piece and has the same structure. Both are provided with cooling channels and a plurality of first clamping blind holes for clamping the end of the test piece. The side walls of the first clamping blind holes are provided with first elastic pieces for providing radial preload, and the bottoms of the first clamping blind holes are provided with second elastic pieces for providing axial preload; A plurality of pull rods, one end of which is passed through the upper clamping member, and the other end of which is passed through the lower clamping member; and A plurality of fixing rings are connected to the two ends of the pull rod and are used to limit the upper clamping piece and the lower clamping piece from moving away from each other.

2. The test piece clamping unit according to claim 1, characterized in that: The clamping unit also includes a plurality of intermediate clamping parts, wherein the intermediate clamping parts are provided with clamping through holes at positions corresponding to the first clamping blind holes or second clamping blind holes are provided at both ends, and at least one clamping through hole is provided on the intermediate clamping parts, and the first elastic part is provided on the side walls of the clamping through hole and the second clamping blind hole, and the second elastic part is provided on the bottom of the second clamping blind hole.

3. The test piece clamping unit according to claim 1 or 2, characterized in that: The first elastic member is a leaf spring, and the second elastic member is a disc spring.

4. The test piece clamping unit according to claim 1 or 2, characterized in that: A gasket is provided at one end of the second elastic member contacting the test member.

5. A multi-layer reinstallable irradiation test assembly, comprising a plurality of clamping units according to any one of claims 1 to 4, characterized in that: It also includes a center rod, a lower tube seat and a locking component. The lower tube seat is fixedly connected to the lower end of the center rod. The clamping units are sequentially sleeved on the center rod and supported by the lower tube seat. The locking component is arranged at the upper end of the center rod for locking the clamping units.

6. The multi-layer reinstallable radiation test assembly according to claim 5, characterized in that: The upper clamping piece and the lower clamping piece are provided with mounting holes in the center, and the cross section of the part of the center rod where the clamping unit is sleeved is perpendicular to the axis and has a polygonal structure. The mounting hole can limit the rotation of the center rod and a gap is reserved as the cooling channel.

7. The multi-layer reinstallable radiation test assembly according to claim 6, characterized in that: One or more holes are provided near the edges of the upper clamping piece and the lower clamping piece as the cooling channel.

8. The multi-layer reinstallable radiation test assembly according to claim 6, characterized in that: The end of the mounting hole of the upper clamping piece and / or the end of the mounting hole of the lower clamping piece are provided with clips that fit with each side surface of the center rod.

9. The multi-layer reinstallable radiation test assembly according to claim 5, characterized in that: The locking component includes an upper tube seat, a lock core and a pressing seat; the portion of the central rod sleeved with the clamping unit is defined as a mounting section, a limiting boss is provided above the mounting section, and the cross section of the limiting boss perpendicular to the axis is a polygonal structure, and the central rod is a bare rod section between the mounting section and the limiting boss; The upper tube seat is sleeved on the mounting section and is provided with a supporting step for supporting the lock core. The distance between the limiting boss and the supporting step is equal to the length of the lock core. The lock core is provided with an inner hole that can cooperate with the limiting boss. After the lock core is inserted into the supporting step, it is rotated to a target angle so that the limiting boss limits the axial displacement of the lock core and the clamping unit. The cross section of the lock core perpendicular to the axis is a polygonal structure, and a step anti-rotation hole is provided inside the clamping seat. The small diameter section of the step anti-rotation hole cooperates with the limiting boss, and the large diameter section of the step anti-rotation hole cooperates with the lock core.

10. The multi-layer reinstallable radiation test assembly according to claim 5, characterized in that: In each of the clamping units, a mixing plate is provided at the lower end of the lower clamping member.

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