A test piece clamping unit and a multi-layer reinstallable irradiation test assembly

Abstract

The present invention relates to the field of research reactor irradiation technology, and provides a test piece clamping unit and a multi-layer removable irradiation test assembly. The clamping unit includes an upper clamping member; a lower clamping member, which is symmetrically arranged with the upper clamping member and has the same structure as the upper clamping member, both of which are provided with cooling channels and a plurality of first clamping blind holes for clamping the ends of the test piece, the side walls of the first clamping blind holes are provided with a first elastic member for providing a radial preload, and the bottoms of the first clamping blind holes are provided with a second elastic member for providing an axial preload; a plurality of pull rods, one end of which is passed through the upper clamping member and the other end is passed through the lower clamping member; and a plurality of fixing rings connected to the two ends of the pull rods for limiting the upper clamping member and the lower clamping member from moving away from each other. The present invention not only enables batch loading of test pieces, but also ensures that each test piece has radial and axial preload.

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 a fuel assembly. Prior to engineering applications, fuel assemblies must undergo in-pile irradiation testing and performance testing to comprehensively evaluate their radiation resistance, providing key experimental data and performance verification for design and development. Depending on the stage of fuel assembly development, varying degrees of in-pile irradiation testing are required. Generally, the final verification step is an assembly-level irradiation test to verify the fuel assembly's structural strength, thermal performance, hydraulic performance, compatibility, operability, radiation resistance, and corrosion resistance, among other properties. This provides reliable operational data for engineering applications.

[0003] The irradiation test assembly is generally a scaled-down fuel assembly. In a research reactor, the fuel element serves as a test piece and needs to be clamped and fixed by a clamping unit to ensure high temperature and high pressure, flow-induced vibration, flow velocity matching and other requirements during the test. For example, the patent document with publication number "CN110580961A" provides a clamping and fixing method for a rod-shaped test piece to meet the above requirements. However, this existing technology 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 irradiation 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 member is symmetrically arranged with the upper end clamping member 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 members for providing radial preload, and the bottoms of the first clamping blind holes are provided with second elastic members 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 both ends of the pull rod and are used to limit the upper end clamping piece and the lower end 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 side walls of the clamping through hole and the second clamping blind hole are provided with the first elastic part, and the bottom of the second clamping blind hole is provided with the second elastic part.

[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 on the end of the second elastic member that contacts the test piece.

[0014] The present invention also provides a multi-layer reinstallable irradiation test assembly, including the clamping unit described in any one of the above items, and also including 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 holes can limit the rotation of the center rod and reserve a gap as the cooling channel.

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

[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 each side surface 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 center rod on which the clamping unit is sleeved is defined as a mounting section, a limiting boss is provided above the mounting section, and a cross-section of the limiting boss perpendicular to the axis is a polygonal structure, and the center rod is a polished 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 support step for supporting the lock core. The distance between the limiting boss and the support 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 support 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 pressing 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. 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 from moving away from each other. 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. 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 loads, and the second elastic part provides an axial preload force for the test piece to buffer axial vibration and impact loads. It can be seen that compared with the prior art, the present invention is not only capable of loading test pieces in batches, but also ensures 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 following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any 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 Schematic diagram of the structure of the upper clamping part Figure 1 ;

[0027] Figure 4 Schematic diagram of the structure 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 cross-sectional view;

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

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

[0034] Figure 11 for Figure 10 Enlarged view of point D;

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

[0036] Figure 13 Front view of the center pole;

[0037] Figure 14 This is the main view of the upper tube seat;

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

[0039] Figure 16 This is the main view of the lock cylinder;

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

[0041] Figure 18 It is a structural diagram of the pressing seat;

[0042] Figure 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- support step, 402- lock core, 403- pressing 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 as the upper clamping member. 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, the present embodiment has five first clamping blind holes 1021, that is, one clamping unit can clamp five test pieces.

[0047] Reference again Figure 2 A first elastic member 106 is provided on the sidewall of the first blind clamping hole 1021. This member provides radial preload for the test piece, elastically supporting and positioning it in the radial direction. It also serves to buffer radial vibration and impact loads, dampening flow-induced vibrations of the test piece caused by the hydraulic scouring of the circuit. Optionally, a leaf spring is used for the first elastic member 106 in this embodiment. Leaf springs can be categorized as straight or curved based on their shape. This embodiment utilizes a curved leaf spring, which can be secured via resistance welding or laser welding.

[0048] A second elastic member 107 is installed at the bottom of the first blind clamping hole 1021. This member provides axial preload for the test piece, buffering axial vibration and impact loads, and dampening flow-induced vibrations generated by the test piece under the hydraulic pressure of the circuit. Alternatively, a disc spring can be used as the second elastic member 107 in this embodiment. Furthermore, due to the high stiffness of disc springs, a gasket is installed on the end of the second elastic member 107 that contacts the test piece to prevent damage to the end of the test piece caused by localized point contact.

[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. A fixing ring 105 is connected to both ends of the pull rod to prevent 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 via a thread. As an option, this embodiment provides three pull rods in a 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. 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. The intermediate clamping members 108 are also provided with two second clamping blind holes 1082 and three clamping through holes 1081. Thus, the clamping unit has a total of four layers. Three long test pieces 700 are positioned between the upper clamping member 102 and the lower clamping member 101. The three long test pieces 700 pass through the clamping through holes 1081 of the intermediate clamping members 108. 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 pull rods in Example 2 and Example 1 should be different. Specifically, the pull rod in Example 2 is longer than the pull rod in Example 1. For ease of understanding, the pull rod in Example 2 is defined as a long pull rod 104, and the pull rod in Example 1 is defined as a short pull rod 103.

[0056] Example 3

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

[0058] As an option, this embodiment includes four clamping units according to Example 1 and one clamping unit according to Example 2. For ease of description, the clamping units according to Example 1 are defined as short clamping units 100, and the clamping units according to Example 2 are defined as long clamping units 150. The four short clamping units 100 have four layers and are loaded with twenty short test pieces 600. The long clamping unit 150 also has four layers and is loaded with eight short test pieces 600 and three long test pieces 700. The test assembly provided in this embodiment has a total of eight layers and is loaded with twenty-eight short test pieces 600 and three long test pieces 700. It should be understood that in other embodiments, different numbers of clamping units according to the two aforementioned embodiments may be selected depending on the number of short test pieces 600 and long test pieces 700 to be loaded. Alternatively, the clamping units provided in the two aforementioned embodiments may be used to load all short test pieces 600, all long test pieces 700, or a mixture of both types of test pieces.

[0059] The lower tube seat 300 is fixedly connected (for example, 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 installation orders can also be used.

[0060] refer to Figure 3 、 Figure 4 and Figure 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 cross-section of the part 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 part of the center rod 200 on which the clamping unit is mounted is defined as the mounting section 201. As an option, the cross-section of the mounting section 201 perpendicular to the axis in this embodiment 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] Furthermore, one or more holes are provided near the edges of the upper and lower clamping members 102 and 101 as cooling channels. For ease of understanding and description, the cooling channel in 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. Alternatively, two second cooling channels 1024 are provided in this embodiment. Furthermore, 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 tightly, and are in flexible contact with the center rod 200, which plays a role in reducing vibration.

[0063] The locking member 400 is provided at the upper end of the center rod 200 and is used to lock the clamping unit. Figure 11 , Figures 13-18 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 support step 4011 for supporting the lock core 402. The distance between the limiting boss 202 and the support step 4011 is equal to the length of the lock core 402. 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). 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 support step 4011, it is rotated to the target angle. 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 polygonal (as an option, this embodiment also has a regular pentagonal structure). The interior of the compression seat 403 is provided with a stepped anti-rotation hole. The small diameter section 4031 of the stepped anti-rotation hole cooperates with the limiting boss 202, and the large diameter section 4032 of the stepped anti-rotation hole cooperates with the lock core 402. In this way, the compression seat 403 cannot rotate relative to the center rod 200, and the lock core 402 cannot rotate relative to the compression seat 403, thereby achieving a locking function. Furthermore, in actual application, a locking nut (not shown) can also be provided on the compression seat 403, and the locking nut is threadedly connected to the center rod 200 to limit the axial position of the compression 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. Figure 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 merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A multi-layer reinstallable irradiation test assembly, comprising a plurality of test piece clamping units, the test piece clamping units comprising an upper clamping piece, a lower clamping piece, a plurality of pull rods and a plurality of fixing rings, the lower clamping piece and the upper clamping piece are symmetrically arranged and have the same structure, both of which are provided with a cooling channel and a plurality of first clamping blind holes for clamping the end of the test piece, the side wall of the first clamping blind hole is provided with a first elastic piece for providing a radial preload, and the bottom of the first clamping blind hole is provided with a second elastic piece for providing an axial preload; one end of the pull rod is passed through the upper clamping piece, and the other end is passed through the lower clamping piece; the fixing ring is connected to both ends of the pull rod, for limiting the upper clamping piece and the lower clamping piece from moving away from each other; it is characterized in that, The test assembly further includes: a center rod, a lower tube seat and a locking component, wherein the lower tube seat is fixedly connected to the lower end of the center rod, the clamping unit is sequentially sleeved on the center rod and supported by the lower tube seat, and the locking component is provided at the upper end of the center rod for locking the clamping unit; The upper clamping piece and the lower clamping piece are provided with mounting holes in their centers. The section of the center rod where the clamping unit is sleeved is a polygonal structure perpendicular to the axis. The mounting holes can limit the rotation of the center rod and reserve a gap as the cooling channel. The locking component includes an upper tube seat, a lock core and a pressing seat; the part of the center rod on which the clamping unit is mounted is defined as an installation section, and a limiting boss is provided above the installation section, and the cross-section of the limiting boss perpendicular to the axis is a polygonal structure, and the center rod is a light rod section between the installation section and the limiting boss; the upper tube seat is mounted on the installation section and is internally provided with a support step for supporting the lock core, and the distance between the limiting boss and the support step is equal to the length of the lock core, and the lock core is internally provided with an inner hole that can cooperate with the limiting boss. After the lock core is inserted into the support step, it is rotated to the 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 the interior of the pressing seat is provided with a step anti-rotation hole, 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.

2. The multi-layer reinstallable radiation test assembly according to claim 1, characterized in that: The clamping unit also includes several intermediate clamping parts, which are provided with clamping through holes at the positions corresponding to the first clamping blind holes or second clamping blind holes at both ends, and at least one clamping through hole is provided on the intermediate clamping parts, and the side walls of the clamping through hole and the second clamping blind hole are provided with the first elastic part, and the bottom of the second clamping blind hole is provided with the second elastic part.

3. The multi-layer reinstallable radiation test assembly 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 multi-layer reinstallable radiation test assembly according to claim 1 or 2, characterized in that: A gasket is provided at one end of the second elastic member that contacts the test member.

5. The multi-layer reinstallable radiation test assembly according to claim 1, 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 channels.

6. The multi-layer reinstallable radiation test assembly according to claim 1, 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 central rod.

7. The multi-layer reinstallable radiation test assembly according to claim 1, characterized in that: In each of the clamping units, a mixing plate is provided at the lower end of the lower clamping piece.

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