A test apparatus and method for testing the vibration erosion of fuel rods.

Abstract

This invention provides a fuel rod vibration erosion test apparatus and method, relating to the field of fuel rod erosion testing technology. The apparatus includes a containment for holding an aqueous solution to simulate the water environment in a nuclear reactor; a test assembly disposed inside the containment for mounting the fuel rod to be tested; an electromagnetic drive assembly disposed on top of the test assembly, which applies an electromagnetic force to the fuel rod to drive it to move along a preset test trajectory; and a controller electrically connected to the electromagnetic drive assembly for controlling the magnitude and direction of the electromagnetic force output by the electromagnetic drive assembly. The electromagnetic drive assembly employs a non-contact drive, with no direct mechanical connection between the electromagnetic coil and the soft magnetic clamp, eliminating errors and damage caused by friction, wear, and transmission backlash between mechanical structures, enabling high-precision, long-life movement of the fuel rod under test.

Description

Technical Field

[0001] This invention relates to the field of fuel rod erosion testing technology, and in particular to a fuel rod vibration erosion test apparatus and its test method. Background Technology

[0002] Fuel rods are the core components of a nuclear reactor, used to support nuclear fuel pellets, initiate and maintain a controlled nuclear fission chain reaction, transfer fission heat, and prevent the leakage of radioactive materials. Therefore, the reliability of fuel rods directly determines the safety of reactor operation. However, complex fluid excitation within a nuclear reactor can induce multi-directional complex fretting erosion between the fuel rods and the positioning grid. This erosion continuously damages the structural integrity of the fuel rods, reducing their reliability and thus affecting the safety of the nuclear reactor. Therefore, fretting erosion testing devices are typically used to test the erosion of fuel rods and assess their reliability. Existing testing devices include mechanical drives, linear motor or voice coil motor drives, and hydraulic drives, which can achieve basic vibration simulation and wear testing, but still have many limitations: mechanical drives can only output fixed waveform vibrations and cannot simulate the complex motion trajectory of fuel rods; linear motor or voice coil motor drives restrict the degrees of freedom of fuel rod movement and are prone to cumulative errors; hydraulic drives, due to the compressibility of hydraulic fluid, are prone to load transfer lag, affecting the accuracy of test results. In addition, there are drawbacks such as inconvenient operation and maintenance, easy wear of mechanical drive components, and the risk of oil leakage in hydraulic drives.

[0003] Therefore, there is an urgent need for a vibration wear testing device and method with better performance. Summary of the Invention

[0004] The purpose of this invention is to address the above problems by providing a fuel rod vibration abrasion test apparatus and method.

[0005] In a first aspect, the present invention provides a fuel rod vibration abrasion test apparatus, comprising: A containment for containing an aqueous solution to simulate the aquatic environment in a nuclear reactor; A test assembly, disposed inside the housing, for mounting the fuel rod to be tested; An electromagnetic drive assembly is disposed on the top of the test assembly. The electromagnetic drive assembly is used to apply an electromagnetic force to the fuel rod under test to drive the fuel rod under test to move according to a preset test trajectory. A controller, electrically connected to the electromagnetic drive assembly, is used to control the magnitude and direction of the electromagnetic force output by the electromagnetic drive assembly.

[0006] According to the technical solutions provided in certain embodiments of the present invention, the test component includes: Mounting bracket, which is fixedly connected to the bottom of the receiving member; Multiple positioning components are arranged sequentially and at intervals along a first direction on the mounting frame, and the fuel rod to be tested passes through the multiple positioning components in sequence.

[0007] According to certain embodiments of the present invention, the electromagnetic drive assembly includes: An electromagnetic drive module is mounted on the top of the mounting bracket, and the electromagnetic drive module includes a plurality of electromagnetic coils distributed in a preset position. A soft magnetic clamp is used to install the soft magnetic clamp onto the top of the fuel rod to be tested, and cooperates with the electromagnetic drive module to output the electromagnetic force.

[0008] According to the technical solutions provided in certain embodiments of the present invention, the positioning component includes: A fixed frame is provided on the mounting bracket; A positioning plate is disposed inside the fixed frame, and the positioning plate is provided with mounting holes, through which the fuel rod to be tested passes; A limit adjustment assembly includes a shim and an adjusting member. The shim and the adjusting member are disposed opposite to each other on two parallel sidewalls of the fixed frame. The adjusting member can move relative to the fixed frame toward or away from the shim to cooperate with the shim to limit and fix the positioning plate.

[0009] According to certain embodiments of the present invention, the soft magnetic clamp includes: A soft magnet fixing component, wherein the soft magnet fixing component has an internal mounting cavity; An elastic locking sleeve is fitted onto the outer wall of the fuel rod to be tested. The elastic sleeve includes an elastic part and a locking part. The elastic part is conical, and the cross-sectional area of ​​the elastic part near the electromagnetic drive module is larger than the cross-sectional area of ​​the mounting cavity away from the electromagnetic drive module. This allows the elastic part to undergo elastic deformation under external force during installation to enter the mounting cavity, and after entering the mounting cavity, it fits against the inner wall of the mounting cavity under the action of elastic restoring force. A locking component is used to engage with the locking component after the elastic part enters the mounting cavity, thereby locking the fuel rod to be tested to the soft magnet fixing component.

[0010] According to the technical solutions provided in some embodiments of the present invention, the apparatus further includes: A sensor, mounted on the mounting bracket, is used to detect the real-time movement position of the fuel rod to be tested; the sensor is electrically connected to the controller, which is also used to adjust the current magnitude and direction of multiple electromagnetic coils according to the real-time movement position and the preset test trajectory.

[0011] According to the technical solutions provided in some embodiments of the present invention, the device further includes at least one adjustment mechanism, which is disposed on the inner wall of the mounting frame and fixedly connected to the mounting frame. The adjustment mechanism is slidably connected to the fixed frame of the positioning component and is used to adjust the spacing between adjacent positioning components to adapt to fuel rods of different lengths to be tested.

[0012] Secondly, the present invention provides an experimental method for the vibration abrasion of fuel rods, comprising: S1. Obtain the shape parameters of the preset test trajectory and the preset test frequency; S2. Obtain the maximum excitation current amplitude of the electromagnetic coil and the azimuth angle of each electromagnetic coil; S3. Calculate the orientation angle corresponding to the target position based on the shape parameters and the preset test frequency; the target position is the position where the fuel rod to be tested will reach at the next moment according to the preset test trajectory. S4. Calculate the magnitude and direction of the target current corresponding to each electromagnetic coil based on the direction angle corresponding to the target position, the maximum excitation current amplitude, and the azimuth angle of each electromagnetic coil; the target current is the current required to output the electromagnetic force needed to move the fuel rod under test to the target position. S5. Adjust the current of each electromagnetic coil according to the magnitude and direction of the target current, so that the fuel rod to be tested moves to the target position under the resultant force of the electromagnetic forces of each electromagnetic coil.

[0013] According to the technical solutions provided in some embodiments of the present invention, the method further includes: Obtain the actual position of the fuel rod under test detected by the sensor at the current moment; Calculate the error value between the actual position of the fuel rod under test at the current moment and the corresponding position on the preset test trajectory; The target current is corrected based on the error value.

[0014] According to the technical solutions provided in certain embodiments of the present invention, error correction is performed on the target current based on the error value, including: according to

[0015] Calculate the corrected target current; where, The corrected target current; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; This is the error value; This is the derivative of the error value with respect to time. This is the direction angle corresponding to the target position; This is the azimuth angle of the electromagnetic coil.

[0016] In summary, this invention provides a fuel rod vibration erosion experimental apparatus, comprising: a container for containing an aqueous solution to simulate the water environment in a nuclear reactor; a test assembly disposed inside the container for mounting the fuel rod to be tested; an electromagnetic drive assembly disposed on top of the test assembly, the electromagnetic drive assembly being used to apply an electromagnetic force to the fuel rod to be tested to drive it to move along a preset test trajectory; and a controller electrically connected to the electromagnetic drive assembly for controlling the magnitude and direction of the electromagnetic force output by the electromagnetic drive assembly. This invention simulates the complex multi-directional motion trajectory of the fuel rod under actual operating conditions by applying an electromagnetic force to the fuel rod under test in an aqueous environment using an electromagnetic drive assembly, driving the fuel rod to move along a preset test trajectory and generating erosion between it and the test assembly, thus completing a vibration erosion experiment of the fuel rod under actual operating conditions. Compared with existing technologies, the electromagnetic drive assembly of this invention employs non-contact drive, eliminating direct mechanical connection between the electromagnetic coil and the soft magnet. This eliminates friction, wear, and transmission backlash between mechanical components, enabling high-precision, long-life movement of the fuel rod under test. Furthermore, this drive method offers high flexibility; by changing the magnitude and direction of the drive current, movement along straight lines, arcs, ellipses, and even more complex trajectories can be achieved. In addition, the electromagnetic drive possesses high-frequency response characteristics and a fast response speed, making it more suitable for the actual high-frequency vibration conditions of fuel rods.

[0017] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this invention do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a fuel rod vibration abrasion test device provided in an embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of a fuel rod vibration abrasion test apparatus provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the test component provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the electromagnetic drive assembly provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the positioning component provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the soft magnetic clamp provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the layout of the electromagnetic coil provided in an embodiment of the present invention; Figure 8 A schematic flowchart of the experimental method for fuel rod vibration abrasion provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of an electromagnetic coil provided in an embodiment of the present invention.

[0020] The text labels in the image represent: 1. Receiving component; 2. Test assembly; 21. Mounting bracket; 211. First mounting plate; 212. Second mounting plate; 213. Third mounting plate; 22. Positioning assembly; 221. Fixing frame; 222. Positioning plate; 223. Gasket; 224. Adjusting component; 3. Electromagnetic drive assembly; 31. Electromagnetic drive module; 311. Electromagnetic coil; 312. Base plate; 32. Soft magnetic clamp; 321. Soft magnetic fixing component; 322. Elastic locking sleeve; 3221. Elastic part; 3222. Locking part; 323. Locking component; 4. Fuel rod to be tested; 5. Controller; 7. Adjusting mechanism. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. This description is merely illustrative and explanatory, and should not be construed as limiting the scope of protection of the present invention in any way. Specifically, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0023] As mentioned in the background section, in view of the problems in the prior art, this embodiment provides a fuel rod vibration erosion test apparatus, including: Container 1 is used to contain an aqueous solution to simulate the water environment in a nuclear reactor. Test component 2, which is located inside the housing 1, is used to install the fuel rod 4 to be tested; Electromagnetic drive component 3 is disposed on the top of test component 2. Electromagnetic drive component 3 is used to apply electromagnetic force to the fuel rod 4 under test to drive the fuel rod 4 under test to move according to a preset test trajectory. Controller 5 is electrically connected to electromagnetic drive assembly 3 and is used to control the magnitude and direction of the electromagnetic force output by electromagnetic drive assembly 3.

[0024] For details, please refer to Figure 1 and Figure 2 The housing 1 includes a sliding base, four side plates, and clamping components. The side plates are made of transparent acrylic glass with a wall thickness of 10mm, capable of withstanding pressure up to 1MPa. The four side plates are fixed to the base using rubber gaskets and bolts, and are connected to each other with sealant. Clamping components are installed on the outer sides of the four side plates to prevent bulging or cracking at the joints under test pressure, which could lead to leakage. The test assembly 2 is located inside the housing 1 and is used to mount the fuel rod 4 to be tested. The fuel rod 4 moves in a plane perpendicular to a first direction, abrading against the test assembly to achieve a vibration abrasion test. The first direction is... Figure 1 The electromagnetic drive assembly 3 is located on top of the test assembly 2. It applies an electromagnetic force to the fuel rod 4 under test to drive it along a preset test trajectory. The controller 5 is electrically connected to the electromagnetic drive assembly 3 and controls the magnitude and direction of the electromagnetic force output by the assembly.

[0025] Compared to existing technologies, the electromagnetic drive component used in this invention is a non-contact drive structure. There is no direct mechanical connection between the electromagnetic coil and the soft magnet, completely eliminating the friction, wear, and transmission backlash problems caused by mechanical connections. This allows the fuel rod under test to achieve high-precision, high-response speed, and long-life movement. Simultaneously, this drive method offers extremely high flexibility; simply adjusting the amplitude and direction of the drive current is sufficient to drive the fuel rod to complete linear, circular, elliptical, and even more complex trajectory movements. Furthermore, the inherent high-frequency response characteristics of electromagnetic drive result in even faster response speeds, better adapting to the high-frequency vibration requirements of the fuel rod under actual operating conditions.

[0026] In a preferred embodiment, test component 2 includes: Mounting bracket 21 is fixedly connected to the bottom of the receiving part 1; Multiple positioning components 22 are arranged sequentially and at intervals on the mounting frame 21 along the first direction, and the fuel rod 4 to be tested passes through the multiple positioning components 22 in sequence.

[0027] Specifically, such as Figure 3As shown, the mounting bracket 21 includes a first mounting plate 211, a second mounting plate 212, and a third mounting plate 213 that are perpendicular to each other. One end of each of the first mounting plate 211, the second mounting plate 212, and the third mounting plate 213 is fixedly connected to the bottom of the receiving member 1. The first mounting plate 211 extends along a second direction, and the second mounting plate 212 and the third mounting plate 213 are arranged parallel to each other and extend along a third direction. Multiple positioning components 22 are distributed sequentially at intervals along a first direction, and both ends of each positioning component 22 are connected to the second mounting plate 212 and the third mounting plate 213, respectively. The fuel rod 4 to be tested passes through multiple positioning components 22 sequentially, thereby achieving positioning of the fuel rod 4 to be tested. The first direction, the second direction, and the third direction are perpendicular to each other, and the first direction is... Figure 1 The middle X-axis direction, the second direction is Figure 1 In the Y-axis direction. In this embodiment, there are 3 positioning components 22, which correspond to the upper, middle and lower sections of the fuel rod 4 to be tested, respectively. This can suppress the bending and fluttering phenomenon that occurs when the fuel rod moves according to the preset test trajectory. However, the number of positioning components 22 can also be adjusted according to actual needs. For example, the number of positioning components 22 can be increased for a longer fuel rod 4 to be tested. No specific limitation is made here.

[0028] In a preferred embodiment, the electromagnetic drive assembly 3 includes: The electromagnetic drive module 31 is mounted on the top of the mounting bracket 21 and includes a plurality of electromagnetic coils 311 distributed in a preset position. The soft magnetic clamp 32 is used to install onto the top of the fuel rod 4 to be tested, and works with the electromagnetic drive module 31 to output electromagnetic force.

[0029] Specifically, such as Figure 4 and Figure 9 As shown, the electromagnetic drive module 31 includes a base plate 312 and eight electromagnetic coils 311 fixedly mounted thereon and distributed at preset positions. Figure 7(Ref. Nos. 1 to 8). The substrate 312 is mounted on the top of the mounting bracket 21 and is made of high-strength aluminum alloy. Its surface is anodized, which improves the structural strength and corrosion resistance of the substrate 312 and reduces the deformation of the substrate 312 during vibration, providing a stable mounting reference for the electromagnetic coils 311. Eight electromagnetic coils 311 are fixedly mounted on the side of the substrate 312 near the fuel rod 4 to be tested by bolts, and anti-slip insulating pads are provided between the electromagnetic coils 311 and the substrate 312 to avoid displacement deviation or loosening between the electromagnetic coils 311 and the substrate 312. In this embodiment, the preset position is arranged as follows: the eight electromagnetic coils 311 are evenly distributed on a circumference of radius R, the center of the circumference is O, the included angle between adjacent electromagnetic coils 311 is 45 degrees, and the line connecting the geometric center of each electromagnetic coil 311 to the center O is the circumferential radius R. The soft magnetic clamp 32 is a moving soft magnetic body made of soft magnetic material (such as electrical pure iron, silicon steel sheet, or amorphous or nanocrystalline soft magnetic alloy), which is mounted on the top of the fuel rod 4 to be tested. When the electromagnetic coil 311 is energized, it generates a magnetic field. This magnetic field changes accordingly with the magnitude and direction of the current in the electromagnetic coil 311. The soft magnetic clamp 32 is subjected to a synchronously changing electromagnetic force in this magnetic field (the magnitude and direction of the electromagnetic force change with the magnetic field), thereby driving the fuel rod 4 to move along a preset test trajectory. The electromagnetic force is either Lorentz force or magnetic reluctance.

[0030] In a preferred embodiment, the positioning component 22 includes: Fixed frame 221, fixed frame 221 is mounted on mounting bracket 21; Positioning plate 222 is set inside the fixed frame 221. The positioning plate 222 is provided with mounting holes, through which the fuel rod 4 to be tested passes. The limit adjustment assembly includes a shim 223 and an adjusting member 224. The shim 223 and the adjusting member 224 are disposed opposite to each other on two parallel side frames of the fixed frame 221. The adjusting member 224 can move relative to the fixed frame 221 toward or away from the shim 223 to cooperate with the shim 223 to limit and fix the positioning plate 222.

[0031] Specifically, such as Figure 3 and Figure 5As shown, the fixed frame 221 is mounted on the mounting bracket 21, and its two ends are fixedly connected to the second mounting plate 212 and the third mounting plate 213 respectively. The fixed connection can be welding or bolt connection, which is not specifically limited here. The positioning plate 222 is set inside the fixed frame 221, and the positioning plate 222 is provided with mounting holes, through which the fuel rod 4 to be tested passes. The limit adjustment assembly includes a gasket 223 and an adjusting member 224. The gasket 223 and the adjusting member 224 are arranged opposite to each other on two parallel side frames of the fixed frame 221. The gasket 223 is made of rubber and plays a role in buffering, vibration reduction and protection. On the one hand, it can absorb the energy generated by vibration, impact and other loads during the experiment, reduce the contact stress concentration between the positioning plate 222 and the fixed frame 221, thereby avoiding structural deformation; on the other hand, it can isolate the rigid contact between the two to prevent rigid friction damage to the surface of the positioning plate 222 and the fixed frame 221 caused by high-frequency vibration. In this embodiment, the adjusting member 224 adopts a threaded adjusting structure (such as an adjusting bolt), which is connected to the frame of the fixed frame 221 by a threaded engagement. It can be rotated to move relative to the fixed frame 221 towards or away from the shim 223. It cooperates with the shim 223 to limit and fix the positioning plate 222. There are two sets of shims 223 and adjusting members 224 to ensure that the positioning plate 222 does not shift or shake in the first and second directions during the experiment.

[0032] In a preferred embodiment, the soft magnet clamp 32 includes: The soft magnet fixing component 321 has an internal mounting cavity; The elastic locking sleeve 322 is sleeved on the outer wall of the fuel rod 4 to be tested. It includes an elastic part 3221 and a locking part 3222. The elastic part 3221 is conical, and the cross-sectional area of ​​the end of the elastic part 3221 near the electromagnetic drive module 31 is larger than the cross-sectional area of ​​the end of the mounting cavity away from the electromagnetic drive module 31, so that it can undergo elastic deformation under the action of external force during installation to enter the mounting cavity, and after entering the mounting cavity, it fits against the inner wall of the mounting cavity under the action of elastic restoring force. The locking member 323 is used to lock the fuel rod 4 to be tested and the soft magnet fixing member 321 after the elastic part 3221 enters the mounting cavity and cooperates with the locking part 3222.

[0033] Specifically, such as Figure 6As shown, the soft magnet fixing component 321 has an internal mounting cavity for accommodating and positioning the elastic locking sleeve 322. The elastic locking sleeve 322 is fitted onto the outer wall of the fuel rod 4 to be tested, and is composed of an elastic part 3221 and a locking part 3222. The elastic part 3221 is conical, with its cross-sectional area near the electromagnetic drive module 31 being larger than the cross-sectional area of ​​the mounting cavity away from the electromagnetic drive module 31. This allows the elastic part 3221 to undergo elastic deformation under external force during assembly, smoothly entering the mounting cavity, and then tightly fitting against the inner wall of the mounting cavity under its own elastic restoring force. This elastic conical structure of the elastic part 3221 can undergo radial contraction and expansion under external force, compensating for machining and assembly errors through elastic deformation, reducing the precision requirements of part machining, and simultaneously buffering the impact load generated by vibration, reducing stress concentration and damage to the fuel rod 4 to be tested. During assembly, as external force is applied, the elastic part 3221 contracts at the end near the electromagnetic drive module 31 until it can enter the mounting cavity through the opening at the end away from the electromagnetic drive module 31. After entering the mounting cavity, it expands under the action of elastic restoring force, thus tightly fitting against the inner wall of the mounting cavity. The locking member 323 cooperates with the locking part 3222 of the elastic locking sleeve 322. When the elastic part 3221 is fully inserted into the mounting cavity and fits against the inner wall, the force applied by the locking member 323 maintains the conical surface fit between the elastic part 3221 and the inner wall of the mounting cavity, locking the fuel rod 4 to be tested and the soft magnet fixing member 321. In this embodiment, the locking member 323 and the locking part 3222 are connected by threads, and reliable locking is achieved by thread preload. However, other connection methods with the same preload effect can also be used, and no specific limitation is made here.

[0034] In a preferred embodiment, the apparatus further includes: The sensor is mounted on the mounting bracket 21 and is used to detect the real-time movement position of the fuel rod 4 to be tested. The sensor is electrically connected to the controller 5, which is also used to adjust the magnitude and direction of the current of multiple electromagnetic coils 311 according to the real-time movement position and the preset test trajectory.

[0035] Specifically, in this embodiment, the sensing element includes a first sensor and a second sensor, both of which are laser displacement sensors and are respectively mounted on the first mounting plate 211 and the second mounting plate 212 by bolts, for detecting the real-time movement position of the fuel rod 4 under test in the first direction and the second direction, respectively. The axes of the detection heads of the first and second sensors are at the same height as the geometric center of the soft magnetic clamp 32 to ensure detection accuracy. The sensing element is electrically connected to the controller 5. The real-time movement position of the fuel rod 4 under test detected by the sensor 6 in the first and second directions is fed back to the controller 5. The controller 5 adjusts the current magnitude and direction of multiple electromagnetic coils 311 according to the real-time movement position and the preset test trajectory. The controller includes a central processing unit and a multi-channel power amplifier. The central processing unit adopts an industrial-grade PLC (Programmable Logic Controller) and communicates with the multi-channel power amplifier via an Ethernet interface (communication rate 100Mbps). The multi-channel power amplifier amplifies the control signal output by the central processing unit into a drive current adapted to the electromagnetic coils, and its output terminal is connected to each electromagnetic coil 311 through a shielded cable to make each electromagnetic coil 311 generate a corresponding magnetic field. In addition, shielded cables can be protected with metal corrugated pipes to avoid electromagnetic interference and the influence of the external environment on signal transmission, ensuring the stability and accuracy of the drive current output.

[0036] In a preferred embodiment, the device further includes at least one adjustment mechanism 7, which is disposed on the inner wall of the mounting frame 21 and fixedly connected to the mounting frame 21. The adjustment mechanism 7 is slidably connected to the fixing frame 221 of the positioning component 22 and is used to adjust the spacing between adjacent positioning components 22 to accommodate fuel rods 4 of different lengths to be tested.

[0037] Specifically, such as Figure 2 As shown, the device also includes at least one adjustment mechanism 7, which is disposed on the inner wall of the mounting frame 21 and fixedly connected to the mounting frame 21. The adjustment mechanism 7 is slidably connected to the fixed frame 221 of the positioning component 22. The adjustment mechanism 7 can adopt a structure of sliding rail and slider (or lead screw slide, guide rod, etc.), and the adjustment mechanism 7 is equipped with locking positioning components (such as locking bolts, elastic buckles, etc.). When the distance between adjacent positioning components 22 is adjusted to a position that adapts to the length of the fuel rod 4 to be tested, the relative position of the adjustment mechanism 7 and the fixed frame 221 is fixed by the locking positioning components to prevent the distance from loosening due to vibration during the experiment. The adjustment mechanism 7 can flexibly adjust the installation height of the positioning component 22 according to the actual length of the fuel rod 4 to be tested, adapting to the fuel rod size requirements of different specifications of nuclear fuel assemblies. There is no need to replace the positioning component 22 or modify the mounting frame 21; adaptation can be completed simply by sliding adjustment, simplifying the operation process and improving the versatility and practicality of the device.

[0038] This embodiment also provides an experimental method for the vibration abrasion of fuel rods, such as... Figure 8 As shown, it includes: S1. Obtain the shape parameters of the preset test trajectory and the preset test frequency; Specifically, the preset test frequency is determined in advance according to the test requirements. The shape parameters can be determined by the shape of the preset test trajectory. For example, when the preset test trajectory is a straight line, the shape parameter is the amplitude A; when the preset test trajectory is an ellipse, the shape parameters are the major axis dimension a and the minor axis dimension b; if the preset test trajectory is an arc or other complex curve, the shape parameters can correspond to the arc radius, curve curvature, and other shape parameters.

[0039] S2. Obtain the maximum excitation current amplitude of electromagnetic coil 311 and the azimuth angle of each electromagnetic coil 311; Specifically, the maximum excitation current amplitude of the electromagnetic coil 311 is the maximum current that the electromagnetic coil 311 can safely output, which determines the upper limit of the electromagnetic force generated by the electromagnetic coil 311. It is related to the number of turns, material, and specific structure of the electromagnetic coil 311. When the electromagnetic coil 311 is determined, its maximum excitation current amplitude is also determined accordingly. Based on... Figure 7 After determining the preset position of each electromagnetic coil 311, the azimuth angle of each electromagnetic coil 311 is also determined. In this embodiment, the numbering and azimuth angle of the electromagnetic coils 311 are as follows: As shown in Table 1: Table 1. Correspondence between the numbering and azimuth angle of the electromagnetic coils.

[0040] S3. Calculate the orientation angle corresponding to the target position based on the shape parameters and the preset test frequency; the target position is the position where the fuel rod 4 to be tested will reach at the next moment according to the preset test trajectory. Specifically, the preset test trajectory is a simulated motion path (which can be a straight line, circular arc, ellipse, or other complex trajectory) pre-set based on the motion characteristics of the fuel rod under test under actual nuclear reactor operating conditions. The fuel rod 4 under test reaches a spatial point at each moment, and all spatial points are sequentially connected to form a complete preset test trajectory. The target position is the next consecutive spatial point that the fuel rod 4 under test will reach along the preset test trajectory, based on its current position. Calculating the direction angle corresponding to the target position determines the direction of motion of the fuel rod from the current position to the target position. The direction angle corresponding to the target position needs to be calculated in conjunction with the shape parameters of the preset test trajectory and the preset test frequency.

[0041] For example, if the preset test trajectory is a straight line, the direction angle corresponding to the target position is calculated according to the following formula (1): Formula (1) in, This is the direction angle corresponding to the target position; Preset test frequency; For time.

[0042] For example, if the preset test trajectory is an ellipse, the direction angle corresponding to the target position is calculated according to the following formula (2): Formula (2) in, This is the direction angle corresponding to the target position; For time; The target position is located along the major axis. ; The target position is located along the minor axis. a represents the major axis dimension; b represents the minor axis dimension.

[0043] S4. Based on the direction angle corresponding to the target position, the maximum excitation current amplitude, and the azimuth angle of each electromagnetic coil 311, calculate the magnitude and direction of the target current corresponding to each electromagnetic coil 311; the target current is the current required to output the electromagnetic force required to move the fuel rod 4 under test to the target position. Specifically, based on the direction angle corresponding to the target position, the maximum excitation current amplitude, and the azimuth angle of each electromagnetic coil 311, the magnitude and direction of the target current corresponding to each electromagnetic coil 311 are calculated. This converts the electromagnetic force required to move the fuel rod 4 under test to the target position into current commands for each electromagnetic coil 311. The purpose is to independently control the magnitude and direction of the current of each electromagnetic coil 311 to energize each electromagnetic coil 311 and generate a magnetic field. This magnetic field is then generated in conjunction with the soft magnetic clamp 32 to produce a suitable electromagnetic force, ensuring that the fuel rod 4 under test can move stably along the preset trajectory. At the same time, this avoids coupling interference between different electromagnetic coils 311 and improves trajectory control accuracy.

[0044] The magnitude and direction of the target current corresponding to each electromagnetic coil 311 are calculated according to the following formula (3): Formula (3) in, The target current corresponding to each electromagnetic coil 311; This is the direction angle corresponding to the target position; The azimuth angle of the electromagnetic coil; This represents the maximum excitation current amplitude.

[0045] S5. Adjust the current of each electromagnetic coil 311 according to the magnitude and direction of the target current so that the fuel rod 4 to be tested moves to the target position under the resultant force of the electromagnetic forces of each electromagnetic coil 311.

[0046] Specifically, the target current corresponding to each electromagnetic coil 311 is when The electromagnetic force exerted by each electromagnetic coil 311 on the fuel rod 4 under test is calculated according to the following formula (4): Formula (4) in, Apply an electromagnetic force to each of the electromagnetic coils to the fuel rod under test; These are the calibration constants for each electromagnetic coil; The target current corresponding to each electromagnetic coil.

[0047] The value of is related to the number of turns, distance, core, and connection structure of the electromagnetic coil. After each electromagnetic coil is determined, The value of is also determined accordingly.

[0048] The resultant force of the electromagnetic force on the fuel rod to be tested needs to be calculated using the following formulas (5), (6) and (7): Formula (5) Formula (6) Formula (7) in, The sum of the components of the electromagnetic force exerted by each electromagnetic coil on the fuel rod under test in the first direction; This is the sum of the components of the electromagnetic force exerted by each electromagnetic coil on the fuel rod under test in the second direction; Apply an electromagnetic force to each of the electromagnetic coils to the fuel rod under test; The resultant force of the electromagnetic forces acting on the fuel rod to be tested; This is the azimuth angle of the electromagnetic coil.

[0049] Therefore, adjusting the current of each electromagnetic coil 311 according to the magnitude and direction of the target current converts the calculated target current into the actual output current of the electromagnetic coil 311, thereby generating a corresponding electromagnetic force so that the fuel rod 4 to be tested moves to the target position under the combined force of the electromagnetic forces of each electromagnetic coil 311.

[0050] In a preferred embodiment, the method further includes: Obtain the current actual position of the fuel rod 4 under test detected by the sensor; Calculate the error between the actual position of the fuel rod 4 under test at the current moment and the corresponding position on the preset test trajectory; The target current is corrected based on the error value.

[0051] Specifically, the coordinates of the actual position of the fuel rod 4 under test in the first direction at the current moment are detected by the first and second sensors of the sensing element, respectively. Coordinates of the actual position in the second direction .

[0052] The error between the actual position of the fuel rod 4 under test at the current moment and the corresponding position on the preset test trajectory is calculated according to the following formulas (8), (9), and (10): Formula (8) Formula (9) Formula (10) in, This is the error value; The error value between the actual position of the fuel rod under test in the first direction at the current moment and the corresponding position on the preset test trajectory; The error value between the actual position of the fuel rod under test in the first direction at the current moment and the corresponding position on the preset test trajectory; This represents the current position of the fuel rod to be tested in the first direction on the preset test trajectory; This represents the current position of the fuel rod to be tested in the first direction on the preset test trajectory.

[0053] For example, when the preset test trajectory is a straight line, and Calculate according to the following formulas (11) and (12): Formula (11) =0 formula (12) in, This represents the current position of the fuel rod to be tested in the first direction on the preset test trajectory; A represents the current position of the fuel rod under test in the first direction on the preset test trajectory; A is the amplitude. Preset test frequency; For time.

[0054] For example, when the preset test trajectory is an ellipse, and Calculate according to the following formulas (13) and (14): Formula (13) Formula (14) in, This represents the current position of the fuel rod to be tested in the first direction on the preset test trajectory; This represents the current position of the fuel rod to be tested in the first direction on the preset test trajectory; Preset test frequency; denoted as time; a represents the major axis dimension; b represents the minor axis dimension.

[0055] In a preferred embodiment, the corrected target current is calculated according to the following formula (15): Formula (15) in, The corrected target current; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; This is the error value; This is the derivative of the error value with respect to time. This is the direction angle corresponding to the target position; This is the azimuth angle of the electromagnetic coil.

[0056] Specifically, , , The data obtained through calibration experiments on the fuel rod vibration abrasion test device is stored in controller 5 and will not change due to different preset test trajectories.

[0057] The fuel rod vibration and erosion experimental apparatus provided by this invention adjusts the magnitude and direction of the electromagnetic force between the electromagnetic coil and the soft magnetic clamp by controlling the target current output to the electromagnetic coil. This causes the fuel rod under test to move along a preset test trajectory and erode with the test components, simulating the complex multi-directional motion trajectory of the fuel rod under actual working conditions, thus completing the vibration and erosion experiment of the fuel rod under actual working conditions. The electromagnetic drive component adopts a non-contact drive, with no direct mechanical connection between the electromagnetic coil and the soft magnetic body, eliminating friction, wear, and transmission backlash caused by mechanical connections, enabling high-precision and long-life movement of the fuel rod under test. Simultaneously, this drive method is highly flexible; by changing the magnitude and direction of the drive current, movement along straight lines, arcs, ellipses, and even more complex trajectories can be achieved. Furthermore, the electromagnetic drive has high-frequency response characteristics and fast response speed, making it more suitable for the actual working conditions of high-frequency vibration of fuel rods. The even distribution of the eight coils on the circumference ensures that the characteristics of the electromagnetic force in any direction in the plane are completely consistent, reducing coupling interference between different degrees of freedom of motion.

[0058] To facilitate understanding by those skilled in the art, the working process of the fuel rod vibration abrasion test apparatus provided by the present invention is as follows: An aqueous solution is injected into the container 1 to simulate the water environment of a nuclear reactor; the fuel rod 4 to be tested is installed on the test assembly 2; the soft magnetic clamp 32 is installed on the top of the fuel rod 4 to be tested; the controller 5 calculates the direction angle corresponding to the target position of the fuel rod 4 at the next moment according to the preset shape parameters and preset test frequency, and then calculates the target current magnitude and direction of each electromagnetic coil 311 based on the direction angle corresponding to the target position at the next moment, the maximum excitation current amplitude, and the azimuth angle of each electromagnetic coil 311; the controller 5 outputs the target current to each electromagnetic coil 311, and the electromagnetic coil 311 generates a magnetic field after being energized, which magnetizes the soft magnetic clamp 32 and interacts with it to generate an electromagnetic force that drives the soft magnetic clamp 32 to move the fuel rod 4 to be tested along the preset test trajectory, thereby generating abrasion between it and the test assembly 2. Meanwhile, the sensor detects the real-time movement position of the fuel rod 4 under test and feeds it back to the controller 5. The controller 5 adjusts the magnitude and direction of the target current in the multiple electromagnetic coils 311 according to the error value between the real-time movement position and the corresponding position on the preset test trajectory at that moment, so as to ensure that the fuel rod 4 under test moves along the preset test trajectory.

[0059] This invention employs electromagnetic drive to move the fuel rod under test along a preset test trajectory. Electromagnetic drive is a non-contact method; there is no direct mechanical connection between the electromagnetic coil of the electromagnetic drive component and the soft magnetic clamp, eliminating the detection errors caused by friction, wear, and transmission backlash in traditional transmission drive modes. This allows the fuel rod under test to move with high precision and a long lifespan. The electromagnetic drive component offers high driving flexibility; by changing the magnitude and direction of the current in the electromagnetic coil, complex trajectories such as straight lines and circular arcs can be achieved. Furthermore, its fast response speed adapts to the high-frequency vibration conditions of the fuel rod under test.

[0060] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A fuel rod vibration abrasion test apparatus, characterized in that, include: The container (1) is used to contain an aqueous solution to simulate the water environment in a nuclear reactor; Test component (2), which is disposed inside the housing (1) and is used to install the fuel rod (4) to be tested. An electromagnetic drive assembly (3) is disposed on the top of the test assembly (2). The electromagnetic drive assembly (3) is used to apply an electromagnetic force to the fuel rod (4) to be tested so as to drive the fuel rod (4) to move according to a preset test trajectory. The controller (5) is electrically connected to the electromagnetic drive assembly (3) and is used to control the magnitude and direction of the electromagnetic force output by the electromagnetic drive assembly (3).

2. The fuel rod vibration abrasion test apparatus according to claim 1, characterized in that, The test component (2) includes: Mounting bracket (21), which is fixedly connected to the bottom of the receiving member (1); Multiple positioning components (22) are arranged sequentially at intervals on the mounting frame (21) along a first direction, and the fuel rod (4) to be tested passes through the multiple positioning components (22) in sequence.

3. The fuel rod vibration abrasion test apparatus according to claim 2, characterized in that, The electromagnetic drive assembly (3) includes: An electromagnetic drive module (31) is mounted on the top of the mounting bracket (21), and the electromagnetic drive module (31) includes a plurality of electromagnetic coils (311) distributed in a preset position. A soft magnetic clamp (32) is used to be installed on the top of the fuel rod (4) to be tested, and cooperates with the electromagnetic drive module (31) to output the electromagnetic force.

4. The fuel rod vibration abrasion test apparatus according to claim 3, characterized in that, The positioning component (22) includes: A fixed frame (221) is disposed on the mounting bracket (21); Positioning plate (222), the positioning plate (222) is disposed inside the fixed frame (221), the positioning plate (222) is provided with mounting holes, and the fuel rod (4) to be tested passes through the mounting holes; The limiting adjustment assembly includes a gasket (223) and an adjusting member (224). The gasket (223) and the adjusting member (224) are disposed opposite to each other on two parallel sidewalls of the fixed frame (221). The adjusting member (224) can move relative to the fixed frame (221) towards or away from the gasket (223) to cooperate with the gasket (223) to limit and fix the positioning plate (222).

5. The fuel rod vibration abrasion test apparatus according to claim 4, characterized in that, The soft magnetic clamp (32) includes: A soft magnet fixing component (321) is provided with an installation cavity inside the soft magnet fixing component (321); The elastic locking sleeve (322) is sleeved on the outer wall of the fuel rod (4) to be tested. It includes an elastic part (3221) and a locking part (3222). The elastic part (3221) is conical, and the cross-sectional area of ​​the elastic part (3221) near the electromagnetic drive module (31) is larger than the cross-sectional area of ​​the mounting cavity away from the electromagnetic drive module (31) so that it can undergo elastic deformation under the action of external force during installation to enter the mounting cavity, and after entering the mounting cavity, it fits against the inner wall of the mounting cavity under the action of elastic restoring force. The locking member (323) is used to cooperate with the locking member (3222) after the elastic part (3221) enters the mounting cavity to lock the fuel rod (4) to be tested and the soft magnet fixing member (321).

6. The fuel rod vibration abrasion test apparatus according to claim 2, characterized in that, The device further includes: The sensor is mounted on the mounting bracket (21) and is used to detect the real-time movement position of the fuel rod (4) to be tested. The sensor is electrically connected to the controller (5), which is also used to adjust the current magnitude and direction of multiple electromagnetic coils (311) according to the real-time movement position and the preset test trajectory.

7. The fuel rod vibration abrasion test apparatus according to claim 4, characterized in that, The device further includes at least one adjustment mechanism (7), which is disposed on the inner wall of the mounting frame (21) and fixedly connected to the mounting frame (21). The adjustment mechanism (7) is slidably connected to the fixed frame (221) of the positioning component (22) and is used to adjust the spacing between adjacent positioning components (22) to accommodate fuel rods (4) of different lengths.

8. A test method for the vibration abrasion of fuel rods, characterized in that, The method is implemented using the fuel rod vibration abrasion test apparatus as described in any one of claims 1-7, and includes: S1. Obtain the shape parameters of the preset test trajectory and the preset test frequency; S2. Obtain the maximum excitation current amplitude of the electromagnetic coil (311) and the azimuth angle of each electromagnetic coil (311); S3. Calculate the orientation angle corresponding to the target position according to the shape parameters and the preset test frequency; the target position is the position that the fuel rod (4) to be tested will reach at the next moment according to the preset test trajectory; S4. Calculate the magnitude and direction of the target current corresponding to each electromagnetic coil (311) based on the direction angle corresponding to the target position, the maximum excitation current amplitude, and the azimuth angle of each electromagnetic coil (311); the target current is the current required to output the electromagnetic force required for the fuel rod (4) to move to the target position. S5. Adjust the current of each electromagnetic coil (311) according to the magnitude and direction of the target current so that the fuel rod (4) to be tested moves to the target position under the combined force of the electromagnetic forces of each electromagnetic coil (311).

9. The experimental method for the vibration abrasion of fuel rods according to claim 8, characterized in that, The method further includes: Obtain the actual position of the fuel rod (4) under test detected by the sensor at the current moment; Calculate the error between the actual position of the fuel rod (4) under test at the current moment and the corresponding position on the preset test trajectory; The target current is corrected based on the error value.

10. The experimental method for fuel rod vibration abrasion according to claim 9, characterized in that, Based on the error value, error correction is performed on the target current, including: according to Calculate the corrected target current; where, The corrected target current; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; This is the error value; This is the derivative of the error value with respect to time. This is the direction angle corresponding to the target position; This is the azimuth angle of the electromagnetic coil.

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