Fuel rod vibration characteristic experimental device

Abstract

The utility model discloses a fuel rod vibration characteristic experiment device which comprises a fuel rod simulation piece, a plurality of grillwork fixing assemblies, an excitation system and a dynamic monitoring assembly. The plurality of grillwork fixing assemblies are arranged at intervals along the length direction of the fuel rod simulation piece, and the fuel rod simulation piece is fixed on one side of the supporting base; the grillwork fixing assembly comprises a grillwork support connected with the supporting foundation, a grillwork and a connecting assembly, wherein two adjacent side edges of the grillwork abut against the grillwork support, and the connecting assembly is matched with grillwork holes in the two adjacent side edges of the grillwork and enables the grillwork to be connected to the grillwork support. And the fuel rod simulation piece is connected to the grillwork hole in the middle area of each grillwork in a penetrating manner. According to the fuel rod vibration characteristic experiment device, the fuel rod simulation piece is fixed on the supporting base through the plurality of grillwork fixing assemblies, the fixed boundary of the fuel rod can be simulated so as to carry out a fuel rod vibration characteristic experiment, the natural vibration frequency, the vibration damping ratio and the vibration mode of the fuel rod can be obtained, and the result is reliable.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel rod vibration characteristic experiments, in particular to a fuel rod vibration characteristic experiment device. Background Art

[0002] In a pressurized water reactor core, fuel rods are subjected to vibrations caused by the excitation mechanisms of the reactor coolant axial flow and the core lateral flow. These vibrations induce relative reciprocating motion at the contact points between the fuel rod cladding and the grid springs or rigid convexities. Long-term reciprocating motion and friction cause abrasion of the fuel rod cladding, which may lead to nuclear fuel leakage. In order to reduce the vibration abrasion of fuel rods, it is necessary to conduct experimental research on the vibration characteristics of fuel rods. In order to simulate the fixed boundary conditions of the fuel rods in the reactor core and ensure the reliability of the experimental results, it is necessary to design corresponding experimental fixtures. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a fuel rod vibration characteristic test device with reliable results.

[0004] The technical solution adopted by the utility model to solve the technical problem is: to provide a fuel rod vibration characteristics experimental device, including a fuel rod dummy, a plurality of grid fixing components, an excitation system for providing an external excitation load to the fuel rod dummy, and a dynamic monitoring component for monitoring the lateral response signal of the fuel rod dummy during vibration;

[0005] Several of the grid fixing assemblies are arranged at intervals along the length direction of the fuel rod simulation to fix the fuel rod simulation on one side of the support base; each of the grid fixing assemblies includes a grid support connected to the support base, a grid with two adjacent side edges abutting the grid support, and a connecting assembly that cooperates with the grid holes on the two adjacent side edges of the grid and connects the grid to the grid support; the fuel rod simulation is inserted into the grid holes in the middle area of ​​each of the grids.

[0006] In some embodiments, the connection assembly includes a first grid fixing plate, a second grid fixing plate, and a plurality of cladding simulation segments; the plurality of cladding simulation segments are distributed and inserted into the grid holes on two adjacent sides of the grid;

[0007] The first grid fixing plate is connected to the grid support and extends to fit into a grid hole on one side of the grid. The first locking assembly is passed through the first grid fixing plate and the cladding simulation section to lock the cladding simulation section to the first grid fixing plate.

[0008] The second grid fixing plate is connected to the grid support and extends to fit into the grid hole on the other adjacent side of the grid. It is passed through the second grid fixing plate and the cladding simulation section through a second locking assembly to lock the cladding simulation section and the second grid fixing plate.

[0009] In some embodiments, the first grid fixing plate includes a first plate body for being matched and connected to the grid support, and a plurality of first branches extending outward from one side of the first plate body, each first branch portion being matched with a grid hole and a cladding simulation section, and a first connection hole for the first locking assembly to pass through is provided on the first branch portion.

[0010] In some embodiments, the second grid fixing plate includes a second plate body for being matched with and connected to the grid support, and a plurality of second branches extending outward from one side of the second plate body, each of the second branches being matched with a grid hole and a cladding simulation segment, and a second connection hole for the second locking assembly to pass through is provided on the second branch.

[0011] In some embodiments, the first branch portion is cross-shaped; the second branch portion is cross-shaped.

[0012] In some embodiments, the grid support has a right-angle area, the grid is arranged in the right-angle area, and the grid abuts against the two inner side surfaces of the right-angle area with two adjacent side edges; the lower ends of the two inner side surfaces of the right-angle area are respectively provided with protruding support parts for supporting the bottom of the grid and connecting with the cladding simulation segment inserted in the grid.

[0013] In some embodiments, the grid support includes a first support portion and a second support portion, the second support portion is vertically connected to the first support portion, and the right-angle area is defined therebetween; the adjacent connected side surfaces of the first support portion and the second support portion form two inner side surfaces of the right-angle area.

[0014] In some embodiments, the cladding simulation segment is a rod segment with a diameter consistent with that of the fuel rod simulation member; and locking holes extending axially inward are respectively provided on opposite end surfaces of the cladding simulation segment.

[0015] In some embodiments, the dynamic monitoring assembly includes a plurality of dynamic sensors; the plurality of dynamic sensors are arranged on the support base at intervals along the length direction of the fuel rod simulation.

[0016] In some embodiments, the fuel rod vibration characteristics experimental device further includes a clamping hoop provided on the fuel rod simulation member, and the clamping hoop is connected to the end of the excitation rod of the excitation system.

[0017] In some embodiments, the fuel rod vibration characteristics experimental device further includes the supporting base.

[0018] The beneficial effects of the present invention are as follows: the fuel rod simulation is fixed to the supporting foundation by a plurality of grid fixing assemblies, which can simulate the fuel rod fixing boundary to carry out the fuel rod vibration characteristic experiment, so as to obtain the natural vibration frequency, vibration damping ratio and vibration mode of the fuel rod. The results are reliable and can be used to verify the fuel rod vibration analysis model. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0020] Figure 1 This is a structural diagram of a fuel rod vibration characteristics experimental device according to an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 Side view of the fuel rod vibration characteristics experimental device shown;

[0022] Figure 3 yes Figure 1 A top view of a grid fixing assembly in the fuel rod vibration characteristics experimental device shown;

[0023] Figure 4 yes Figure 3 A schematic structural diagram of a grid support in the grid fixing assembly shown;

[0024] Figure 5 yes Figure 4 a side view of the illustrated grid support;

[0025] Figure 6 yes Figure 3 A schematic structural diagram of the cladding simulation section in the grid fixing assembly shown;

[0026] Figure 7 yes Figure 3 A schematic structural diagram of the first grid fixing plate in the grid fixing assembly shown;

[0027] Figure 8 yes Figure 3 A schematic structural diagram of the second grid fixing plate in the grid fixing assembly shown. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings.

[0029] like Figure 1-Figure 2As shown, a fuel rod vibration characteristic experimental device according to an embodiment of the present invention may include a support base 100 , a fuel rod simulation 200 , a plurality of grid fixing assemblies 300 , an excitation system 400 , and a dynamic monitoring assembly.

[0030] The fuel rod dummy 200 is secured to the support base 100 via several grid-mounted assemblies 300. The excitation system 400 provides external excitation loads to the fuel rod dummy 200, and the dynamic monitoring assembly monitors the lateral response signals of the fuel rod dummy 200 during vibration. These signals are transmitted to a connected measurement and control system, which then calculates and analyzes the natural vibration frequency, damping ratio, and mode shape of the fuel rod dummy 200.

[0031] Among them, the support base 100 serves as the supporting part of the entire experimental device. It can be a bracket structure or a solid support plate or other structures. The overall length (height) is greater than the length (height) of the fuel rod simulation part 200, providing a stable support for the experimental installation of the fuel rod simulation part 200.

[0032] Fuel rod dummy 200 is designed based on the fuel rods to be tested for vibration characteristics. The length, diameter, and material of the cladding of the fuel rod dummy are tailored to the actual fuel rods. The pellets within the fuel rod dummy 200 are also designed based on the pellets within the actual fuel rods; the pellets do not need to be made of the same material as the actual pellets.

[0033] Several grid fixing assemblies 300 are arranged at intervals along the length (and height) of the fuel rod dummy 200 to secure the fuel rod dummy 200 to one side of the support base 100. The number and distribution of grid fixing assemblies 300 are determined based on the number and distribution of grids in the actual core where the fuel rods are located.

[0034] In some embodiments, all grid fixing components 300 have the same composition and structure.

[0035] refer to Figure 1 and Figure 3Taking a grid fixing assembly 300 as an example, the grid fixing assembly 300 may further include a grid support 10, a grid 20, and a connecting assembly. The grid support 10 is used to connect to the support base 100, so that the grid fixing assembly 300 is fixed to the support base 100; the connection between the grid support 10 and the support base 100 can be achieved by bolts or other fasteners. The grid 20 is positioned on the grid support 10 with two adjacent side edges abutting the grid support 10. The connecting assembly cooperates with the grid holes on the two adjacent side edges of the grid 20 to connect the grid 20 to the grid support 10. The fuel rod dummy 200 is connected to the grid holes in the central area of ​​each grid 20. The connecting assembly is connected between the two side edges of the grid 20 and the grid support 10, forming the fixed boundary of the fuel rod dummy 200, thereby simulating the actual fuel rod fixed boundary.

[0036] Specifically, if Figure 3-Figure 5 As shown, the grid 20 is a square grid with two adjacent sides connected at right angles. To this end, the grid support 10 has a right-angle area 101, and the grid 20 is arranged in the right-angle area 101, with the grid 20 abutting the two inner side surfaces of the right-angle area 101 with two adjacent side edges.

[0037] The grid support 10 has a certain height, which is preferably greater than or equal to the height of the grid 20 , so that the entire grid 20 can be accommodated in the right-angle area 101 .

[0038] The grid support 10 may further structurally include a first support portion 11 and a second support portion 12, wherein the second support portion 12 is vertically connected to the first support portion 11, defining a right-angle area 101 therebetween; the adjacent connected sides of the first support portion 11 and the second support portion 12 form two inner sides of the right-angle area 101.

[0039] Taking the example of a vertically positioned grid support 10, the connecting assembly is located on the top surface of the grid support 10, connecting between the top surface of the grid support 10 and the grid 20. To position the grid 20 within the right-angle region 101, protruding support portions 13 are provided at the lower ends of the two inner side surfaces of the right-angle region 101 for supporting the bottom of the grid 20. Two support portions 13 are provided: one protruding from a side surface of the first support portion 11, and the other protruding from a side surface of the second support portion 12. Each support portion 13 can be a side panel connected to or integrally formed with the grid support 10.

[0040] The connection assembly may further include a first grid fixing plate 31, a second grid fixing plate 32, and a plurality of cladding simulation segments 30. The plurality of cladding simulation segments 30 are distributed and interspersed in the grid holes on two adjacent sides of the grid 20 abutting the grid support 10, with each cladding simulation segment 30 accommodated in one grid hole. The first grid fixing plate 31 is connected to the grid support 10 and extends to fit into the grid hole on one side of the grid 20. A first locking assembly is passed through the first grid fixing plate 31 and the cladding simulation segment 30 to lock the cladding simulation segment 30 to the first grid fixing plate 31. Similarly to the first grid fixing plate 31, the second grid fixing plate 32 is connected to the grid support 10 and extends to fit into the grid hole on the other adjacent side of the grid 20. A second locking assembly is passed through the second grid fixing plate 32 and the cladding simulation segment 30 to lock the cladding simulation segment 30 to the second grid fixing plate 32.

[0041] In conjunction with the structure of the grid support 10 and the arrangement of its support portion 13, the grid 20 is positioned within the right-angled region 101 of the grid support 10. The first grid fixing plate 31 is connected to the top surface of the first support portion 11 and extends above the grid 20. The first locking assembly locks the cladding simulation segment 30 to the first grid fixing plate 31, while also locking the cladding simulation segment 30 and the grid 20 to the grid support 10. The second grid fixing plate 32 is connected to the top surface of the second support portion 12 and extends above the grid 20. The second locking assembly locks the cladding simulation segment 30 to the second grid fixing plate 32, while also locking the cladding simulation segment 30 and the grid 20 to the grid support 10.

[0042] Furthermore, the bottom of the grid 20 is supported on two support portions 13. By locking the cladding simulation segments 30 to the support portions 13, the grid 20 can also be locked to the support portions 13. To this end, each support portion 13 can be provided with a connection hole 131 for connecting a locking assembly. A third locking assembly is connected through the support portion 13 and the cladding simulation segment 30 to lock the cladding simulation segment 30 to the support portion 13. The connection hole 131 on each support portion 13 can be a plurality of single holes, the same number as the cladding simulation segments 30, or a single elongated hole, the length of which is sufficient to lock all the cladding simulation segments 30 within the side grid holes of the grid 20.

[0043] The grid 20 is set according to the actual grid. Figure 2 In the illustrated embodiment, the grid 20 has 5 x 5 grid holes. The two sides of the grid 20 that abut the right-angled region 101 have five grid holes on one side and four grid holes on the other side. The grid holes at the diagonal corners of the two sides are shared. Therefore, the grid holes on one side can accommodate five cladding dummy segments 30, while the grid holes on the other side can accommodate four cladding dummy segments 30.

[0044] The cladding simulation section 30 is a rod section with the same diameter as the fuel rod simulation 200. The cladding simulation section 30 is distributed on both sides of the grid 20, forming a fixed boundary of the fuel rod simulation 200, simulating the fixed boundary outside the fuel rod in the actual core. Figure 6 As shown, to cooperate with the locking assembly, the opposite end surfaces of the cladding simulation segment 30 are respectively provided with locking holes 301 extending axially inward. Within the right-angle region 101, the cladding simulation segment 30 is vertically accommodated in the grid holes on both sides of the grid 20. The locking hole at the upper end of the cladding simulation segment 30 on one side is used to cooperate with the first locking assembly, the locking hole at the upper end of the cladding simulation segment 30 on the other side is used to cooperate with the second locking assembly, and the locking holes at one end of all the cladding simulation segments 30 are used to cooperate with the third locking assembly.

[0045] In some embodiments, reference Figure 4 and Figure 7 The first grid fixing plate 31 includes a first plate body 311 for mating with the grid support 10, and a plurality of first branches 312 extending outward from one side of the first plate body 311. The first plate body 311 is mated to the top surface of the first support portion 11. The first plate body 311 and the top surface of the first support portion 11 are provided with relatively connected locking holes for the insertion of locking components such as bolts. The first branches 312 correspond to the side of the first plate body 311 facing the grid 20. Each first branch 312 is mated to a grid hole and a cladding simulation section 30 on the corresponding side of the grid 20. The first branches 312 are provided with first connection holes 313 for the insertion of the first locking component.

[0046] Preferably, each first branch portion 312 is cross-shaped.

[0047] In some embodiments, reference Figure 4 and Figure 8 The second grid fixing plate 32 includes a second plate body 321 for mating with the grid support 10, and a plurality of second branches 322 extending outward from one side of the second plate body 321. The second plate body 321 is mated to the top surface of the second support portion 12. The second plate body 321 and the top surface of the second support portion 12 are provided with mutually communicating locking holes for the insertion of locking components such as bolts. The second branches 322 correspond to the side of the second plate body 321 facing the grid 20. Each second branch 322 is mated to a grid hole and a cladding simulation section 30, and each second branch 322 is provided with a second connection hole 323 for the insertion of a second locking component.

[0048] Preferably, the second branch portion 322 is cross-shaped.

[0049] In some embodiments, the cladding simulation segment 30 may also be fixed within the grid 20 by means of external straps.

[0050] Another example Figure 1 As shown, the dynamic monitoring assembly is used to monitor the lateral response signal of the fuel rod dummy 200 during vibration, and may further include a plurality of dynamic sensors 500. The plurality of dynamic sensors 500 are arranged on the support base 100 at intervals along the length direction (also the height direction) of the fuel rod dummy 200.

[0051] Preferably, a plurality of dynamic sensors 500 are distributed between every two adjacent groups of connection assemblies corresponding to the fuel rod simulation pieces 200 .

[0052] The dynamic sensor 500 may be a dynamic acceleration sensor, which is installed in a contact manner on the fuel rod dummy 200. The dynamic sensor 500 may also be a dynamic displacement sensor, which is installed in a contact or non-contact manner depending on the specific type of the dynamic displacement sensor.

[0053] The excitation system 400 connects the end of its excitation rod to the fuel rod dummy 200, providing an external excitation load to the fuel rod dummy 200. To this end, a clamp 201 may be fixed to the fuel rod dummy 200, connecting the clamp 201 to the end of the excitation rod of the excitation system 400. The clamp 201 is preferably fixed in the middle of the fuel rod dummy 200 in the axial direction.

[0054] This utility model is suitable for vibration characteristic testing of fuel rods of various reactor types. It can simulate fixed boundary conditions of fuel rods, conduct fuel rod vibration characteristic experiments, and verify the fuel rod vibration analysis model. The experimental results are consistent with those calculated by the fuel rod vibration analysis model. Based on the obtained fuel rod vibration modal response parameters, corresponding measures can be taken to reduce vibration abrasion between the fuel rod cladding and the grid springs or rigid convex.

[0055] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fuel rod vibration characteristics test device, characterized in that: It includes a fuel rod dummy, several grid fixing components, an excitation system for providing an external excitation load to the fuel rod dummy, and a dynamic monitoring component for monitoring the lateral response signal of the fuel rod dummy during vibration; Several of the grid fixing assemblies are arranged at intervals along the length direction of the fuel rod simulation to fix the fuel rod simulation on one side of the support base; each of the grid fixing assemblies includes a grid support connected to the support base, a grid with two adjacent side edges abutting the grid support, and a connecting assembly that cooperates with the grid holes on the two adjacent side edges of the grid and connects the grid to the grid support; the fuel rod simulation is inserted into the grid holes in the middle area of ​​each of the grids.

2. The fuel rod vibration characteristics test device according to claim 1, characterized in that: The connection assembly includes a first grid fixing plate, a second grid fixing plate and a plurality of cladding simulation segments; A plurality of cladding simulation segments are distributed and inserted into the grid holes on two adjacent sides of the grid; The first grid fixing plate is connected to the grid support and extends to fit into a grid hole on one side of the grid. The first locking assembly is passed through the first grid fixing plate and the cladding simulation section to lock the cladding simulation section to the first grid fixing plate. The second grid fixing plate is connected to the grid support and extends to fit into the grid hole on the other adjacent side of the grid. It is passed through the second grid fixing plate and the cladding simulation section through a second locking assembly to lock the cladding simulation section and the second grid fixing plate.

3. The fuel rod vibration characteristics test device according to claim 2, characterized in that: The first grid fixing plate includes a first plate body for being connected to the grid support, and a plurality of first branches extending outward from one side of the first plate body, each first branch being matched with a grid hole and a cladding simulation section, and a first connection hole for the first locking assembly to pass through is provided on the first branch; The second grid fixing plate includes a second plate body for being matched with and connected to the grid support, and a plurality of second branches extending outward from one side of the second plate body. Each of the second branches is matched with a grid hole and a cladding simulation section, and a second connection hole for the second locking assembly to pass through is provided on the second branch.

4. The fuel rod vibration characteristics test device according to claim 3, characterized in that: The first branch portion is in a cross shape; the second branch portion is in a cross shape.

5. The fuel rod vibration characteristics test device according to claim 2, characterized in that: The grid support has a right-angle area, and the grid is arranged in the right-angle area. The grid abuts the two inner side surfaces of the right-angle area with two adjacent side edges; the lower ends of the two inner side surfaces of the right-angle area are respectively provided with protruding support parts for supporting the bottom of the grid and connecting with the cladding simulation section inserted in the grid.

6. The fuel rod vibration characteristics test device according to claim 5, characterized in that: The grid support includes a first support portion and a second support portion, the second support portion is vertically connected to the first support portion, and the right angle area is defined therebetween; the adjacent connected side surfaces of the first support portion and the second support portion form two inner side surfaces of the right angle area.

7. The fuel rod vibration characteristics test device according to claim 2, characterized in that: The cladding simulation section is a rod section with a diameter consistent with that of the fuel rod simulation member; the opposite end surfaces of the cladding simulation section are respectively provided with locking holes extending axially inward.

8. The fuel rod vibration characteristics test device according to any one of claims 1 to 7, characterized in that: The dynamic monitoring assembly includes a plurality of dynamic sensors; the plurality of dynamic sensors are arranged on the support base at intervals along the length direction of the fuel rod simulation.

9. The fuel rod vibration characteristics test device according to any one of claims 1 to 7, characterized in that: The fuel rod vibration characteristic experimental device further includes a clamping hoop provided on the fuel rod simulation piece, and the clamping hoop is connected to the end of the excitation rod of the excitation system.

10. The fuel rod vibration characteristics test device according to any one of claims 1 to 7, characterized in that: The fuel rod vibration characteristics experimental device also includes the supporting base.

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