An experimental device and simulation method for eccentric rod drop of reactor control rods

Abstract

The present invention provides an experimental device and a simulation method for the eccentric dropping of a reactor control rod. The experimental device includes a support frame, a leveling plate, a guide tube, an air bearing, a control rod, a clamping mechanism, an air circuit unit, and a measuring unit. The leveling plate is horizontally arranged, and the inner support frame is vertically fixed on the upper part of the leveling plate. The guide tube is vertically installed on the top surface of the leveling plate. The air bearing is installed on the upper part of the guide tube. The control rod is vertically installed on the upper part of the air bearing. The clamping mechanism is arranged on the top of the support frame. The air circuit unit and the measuring unit are located outside the support frame and are connected to the air bearing through a supply pipeline. The present invention can study the dropping process, dropping time, pore water pressure, flow field, hydrodynamic characteristics, and dropping impact force of the reactor control rod. The air bearing is used to achieve precise positioning, especially suitable for the simulation of the eccentric dropping of the control rod, as well as the study of problems such as fluid-structure interaction during the falling of flexible structures. It is beneficial to the analysis of the eccentric dropping process and mechanism, and the results can provide a scientific basis for engineers to design and install control rod drive mechanisms, etc.

Description

Technical Field

[0001] The present invention relates to the fields of nuclear engineering, ocean engineering technology, etc., and particularly relates to a reactor control rod eccentric dropping rod experimental device and a simulation method. Background Technique

[0002] Control rods are made of materials such as boron and cadmium that are easy to absorb neutrons. When a loss-of-coolant accident or earthquake occurs, the control rod assembly is released and quickly inserted into the reactor core under its own gravity to shut down the reactor, preventing the accident from expanding. As a safety shutdown device, the dropping problem of the control rod assembly is of crucial importance. If the dropping time is too long, or there is a situation such as rod jamming during the dropping process, it will trigger extremely serious nuclear accidents. Therefore, the research on the control rod dropping process is very important. Usually, guide tubes made of stainless steel or zirconium-4 alloy are used to guide the movement of the control rod, and there is coolant in the guide tube. On the one hand, the gap between the guide tube and the control rod is extremely small, resulting in a large blocking effect; on the other hand, due to manufacturing and installation deviations, the axes of the control rod and the guide tube are usually misaligned, or there is an eccentric effect, which will affect the dropping process of the control rod and the impact force of the dropping rod; under seismic conditions, the influence of guide tube vibration and the collision and friction between the guide tube and the control rod also need to be considered. Therefore, simulating the eccentric dropping of the control rod in the laboratory has important engineering value and scientific significance.

[0003] Due to the extremely small gap between the guide tube and the control rod, even a slight deviation between the control rod axis and the guide tube axis will cause a sharp change in the eccentricity, and it is very difficult to adjust and control the eccentricity. Summary of the Invention

[0004] To solve the technical problems existing in the above background technique, the present invention provides a reactor control rod eccentric dropping rod experimental device and a simulation method, which can accurately adjust and control the eccentricity and can accurately, efficiently and conveniently realize the simulation of eccentric dropping of the rod.

[0005] To solve the above technical problems, a reactor control rod eccentric drop rod experimental device provided by the present invention includes a support frame, a leveling plate, a guide tube, an air bearing, a control rod, a clamping mechanism, an air circuit unit, and a measurement unit; the leveling plate is horizontally arranged, and the inner support frame is vertically and fixedly installed on the upper part of the leveling plate; the guide tube is vertically installed on the top surface of the leveling plate; the air bearing is installed on the upper part of the guide tube; the control rod is vertically installed on the upper part of the air bearing; the clamping mechanism is arranged on the top of the support frame; the air circuit unit and the measurement unit are located outside the support frame and are connected to the air bearing through an air supply pipeline; the measurement unit includes a measurement terminal and a high-speed mobile tracking camera measurement instrument, a wire displacement sensor, an impact force sensor, a pore water pressure sensor, and a particle image velocimetry instrument connected to the measurement terminal through a data cable; the high-speed mobile tracking camera measurement instrument is installed outside the experimental device; the wire displacement sensor is installed on the top of the support frame; the impact force sensor and the pore water pressure sensor are installed at the bottom end of the guide tube; the particle image velocimetry instrument is installed outside the experimental device.

[0006] For the reactor control rod eccentric drop rod experimental device, where: the air bearing is located inside the middle section of the support frame, and it includes an air bearing sleeve mounting seat, an air bearing sleeve, an air bearing sleeve fixing plate, and an air bearing sleeve mounting flange; the lower part of the air bearing sleeve mounting seat is installed with the air bearing sleeve mounting flange and is fixedly installed on the top of the guide tube through the air bearing sleeve mounting flange; the air bearing sleeves are installed on the inner sides of the upper and lower ends of the air bearing sleeve mounting seat; the air bearing sleeve fixing plate is horizontally installed on the upper part of the air bearing sleeve mounting seat and is fixedly connected to the support frame at both ends.

[0007] For the reactor control rod eccentric drop rod experimental device, where: the lower part of the air bearing sleeve mounting seat is also provided with an air inlet and a drain port.

[0008] For the reactor control rod eccentric drop rod experimental device, where: the air circuit unit includes an air pump and the air supply pipeline; the air pump is connected to the air bearing sleeve through the air supply pipeline.

[0009] For the reactor control rod eccentric drop rod experimental device, where: the control rod is located inside the upper end of the support frame, and it includes a control rod main body and a clamping sling; the lower end of the control rod main body passes through the air bearing sleeve fixing plate and is inserted into the inner side of the air bearing sleeve, and the upper end of the control rod main body extends above the top of the support frame and the extending end is installed with the clamping sling; the control rod main body can move up and down in the air bearing sleeve.

[0010] The experimental device for eccentric rod drop of the reactor control rod, wherein: the leveling plate includes a first leveling plate arranged horizontally and a second leveling plate fixedly installed in the center of the top surface of the first leveling plate in a matching manner; threaded holes for the leveling plate are vertically and correspondingly opened along the circumferential edge area of the second leveling plate, and the levelness of the second leveling plate can be adjusted by screwing a screw rod into the threaded holes for the leveling plate.

[0011] The experimental device for eccentric rod drop of the reactor control rod, wherein: the guide tube is located inside the support frame and includes a guide tube main body, a position adjustment plate fixedly installed horizontally at the bottom end of the guide tube main body, and a fixing plate fixedly installed horizontally at the top end of the guide tube main body; the position adjustment plate is fixedly installed on the top surface of the second leveling plate, and vertically penetrating chutes are symmetrically opened in the relative two side areas of the position adjustment plate; the position adjustment plate can be slid back and forth through the chutes to adjust its lateral position on the second leveling plate.

[0012] The experimental device for eccentric rod drop of the reactor control rod, wherein: the clamping mechanism includes a mounting plate, a moving guide rail, a slider, a clamping plate, a servo motor, and a position induction switch; the mounting plate is fixedly installed on the top of the support frame in a matching manner; the moving guide rail is fixedly installed on the top surface of the mounting plate in a matching manner; the slider is slidably installed on the moving guide rail in a matching manner; the clamping plate is fixedly installed on the slider in a matching manner; the servo motor is installed at one end of the moving guide rail in a matching manner, and its power output end is connected to the slider through a lead screw nut pair in a matching manner; the position induction switch is installed on the moving guide rail in a matching manner.

[0013] A method for simulating eccentric rod drop of a reactor control rod, based on the above experimental device for eccentric rod drop of the reactor control rod, mainly includes the following steps:

[0014] (1) Adjust the level of the leveling plate of the experimental device, and adjust so that the guide tube, air bearing, and control rod of the experimental device are kept vertical.

[0015] (2) Apply more than one known and determined displacement value to the control rod of the experimental device, record the corresponding voltage value of the pull rope displacement sensor of the measurement unit of the experimental device, and then determine the calibration coefficient of the pull rope displacement sensor according to the displacement value and the voltage value.

[0016] (3) Calibrate the high-speed mobile tracking camera measuring instrument of the experimental device.

[0017] (4) Adjust the horizontal position of the guide tube of the experimental device so that the distance between the guide tube of the experimental device and the control rod of the experimental device reaches the experimental predetermined eccentricity. After lifting the control rod of the experimental device to a predetermined height, clamp it through the clamping mechanism of the experimental device.

[0018] (5) Add experimental fluid into the guide tube of the experimental device until it reaches a predetermined height. Loosen the clamping mechanism of the experimental device to release the control rod of the experimental device and let it fall vertically. Synchronously measure the falling process of the control rod of the experimental device, pore water pressure, impact force when the control rod touches the bottom, and flow field structure.

[0019] (6) For the seismic condition, install the experimental device on the shaking table, adjust the vibration parameters of the shaking table, and repeat the aforementioned steps (4) and (5) to simulate the seismic condition.

[0020] In the method for simulating the eccentric dropping of the reactor control rod, in step (2), determining the calibration coefficient of the wire displacement sensor according to the displacement value and voltage value specifically means: fitting the displacement value and voltage value to obtain the calibration coefficient of the wire displacement sensor.

[0021] Adopting the above technical solution, the present invention has the following beneficial effects:

[0022] The experimental device and simulation method for the eccentric dropping of the reactor control rod of the present invention can accurately adjust two parameters of the blockage rate and eccentricity, study the dropping process of the reactor control rod, dropping time, pore water pressure, flow field, hydrodynamic characteristics, and dropping impact force, use an air-floating bushing to achieve precise positioning, and are especially suitable for simulating the eccentric dropping of the control rod and studying problems such as fluid-structure interaction of the flexible structure falling, which is beneficial to the analysis of the eccentric dropping process and mechanism, and the results can provide a scientific basis for engineers to design and install control rod drive mechanisms, etc. Description of the Drawings

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic diagram of the overall structure of the experimental device for the eccentric dropping of the reactor control rod of the present invention;

[0025] Figure 2 It is a top view of the leveling plate of the experimental device for the eccentric dropping of the reactor control rod of the present invention;

[0026] Figure 3 It is a front view of the leveling plate of the experimental device for the eccentric dropping of the reactor control rod of the present invention;

[0027] Figure 4 It is a front view of the guide tube of the experimental device for the eccentric dropping of the reactor control rod of the present invention;

[0028] Figure 5 It is the upward view of the guide tube of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0029] Figure 6 It is the front view of the air bearing of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0030] Figure 7 It is the left view of the air bearing of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0031] Figure 8 It is the top view of the air bearing of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0032] Figure 9 It is the front view of the clamping mechanism of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0033] Figure 10 It is the top view of the clamping mechanism of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0034] Figure 11 It is the left view of the clamping mechanism of the experimental device for the eccentric rod dropping of the reactor control rod of the present invention;

[0035] Figure 12 It is the flow chart of the simulation method for the eccentric rod dropping of the reactor control rod of the present invention. Detailed implementation manners

[0036] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "inside", "above", "below", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The following further explains and illustrates the present invention in combination with specific embodiments.

[0040] As Figure 1 shown, the experimental device for eccentric rod dropping of the reactor control rod of the present invention includes a support frame 1, a leveling plate 2, a guide tube 3, an air bearing 4, a control rod 5, a clamping mechanism 6, an air circuit unit 7, and a measurement unit 8.

[0041] The support frame 1 is a rectangular frame structure, which includes columns 11, cross beams 12, a top plate 13, and top screw rods 14. Among them, the columns 11 are four vertical and rectangularly distributed columns, all made of columnar aluminum profiles. The cross beams 12 are horizontally connected between the middle sections of the four columns 11, specifically including four first cross beams 121 and three second cross beams 122 located above the four first cross beams 121; threaded holes of the cross beams are horizontally and throughly opened in the middle sections of the four first cross beams 121. The top plate 13 is also a square plate structure and is horizontally and fixedly installed at the top ends of the four columns 11, and a through hole is vertically and throughly opened from the center of the top surface. There are four top screw rods 14, which respectively pass horizontally through the threaded holes in the middle sections of the four first cross beams 121.

[0042] As Figures 2 to 3 shown, the leveling plate 2 is horizontally installed at the bottom end of the support frame 1, and it includes a first leveling plate 21 and a second leveling plate 22 horizontally and fixedly arranged at the center of the top surface of the first leveling plate 21. The first leveling plate 21 is a square leveling plate, which is installed on a self-leveling floor or a vibrating table to ensure its levelness; the four columns 11 of the support frame 1 are respectively vertically and fixedly arranged at the four corners of the top surface of the first leveling plate 21; a set of first assembly holes 211 for installing the columns 11 are provided at the four corners of the first leveling plate 21, and a plurality of second assembly holes 212 (the second assembly holes 212 are used to fix the first leveling plate 21 on a self-leveling floor or a vibrating table) are arranged along the outer circumference of the second leveling plate 22. The second leveling plate 22 is a circular leveling plate, and leveling plate threaded holes 221 are vertically opened along the peripheral edge area, and a plurality of third assembly holes 222 for installing the guide tube 3 are provided in the central area; in this embodiment, the leveling plate threaded holes 221 are 8 threaded holes at a 45° angle, and screws can be screwed into the leveling plate threaded holes 221 to further adjust the levelness of the second leveling plate 22 to ensure levelness. The leveling plate 2 is installed on a vibrating table, and the simulation of rod dropping under seismic conditions can be realized.

[0043] As shown Figures 4 to 5 in the figure, the guiding tube 3 is vertically installed on the top surface of the second adjusting plate 22 of the adjusting plate 2 and is located inside the support frame 1. The guiding tube 3 includes a guiding tube main body 31, a position adjusting plate 32 horizontally fixed at the bottom end of the guiding tube main body 31, and a fixing plate 33 horizontally fixed at the top end of the guiding tube main body 31. The position adjusting plate 32 is a square plate structure and is fixedly installed at the center of the top surface of the second adjusting plate 22 of the adjusting plate 2. Two vertically penetrating sliding grooves 321 are symmetrically formed in the opposite side regions of the position adjusting plate 32; the position adjusting plate 32 can slide back and forth on the second adjusting plate 22 through the two sliding grooves 321 to adjust the horizontal position. The guiding tube 3 can move horizontally on the adjusting plate 2 through the two sliding grooves 321. Once the horizontal position of the guiding tube 3 is adjusted, the centering state or the eccentric state between the guiding tubes 3 is controlled, and the eccentricity of the eccentric state is constant, so that centering or eccentricity can be accurately controlled. The control rod 5 can change the material to adjust the weight and stiffness. The guiding tube 3 can adjust the blockage rate by changing the inner diameter. The guiding tube 3 adjusts the eccentricity by changing the horizontal position.

[0044] In this embodiment, the guiding tube main body 31 is made of acrylic or stainless steel. Due to the transparency of acrylic, it is convenient to measure the falling process of the falling rod non-contact with a high-speed mobile tracking camera measuring instrument.

[0045] As shown Figures 6 to 8 in the figure, the air floating bearing 4 is installed on the upper part of the fixing plate 33 of the guiding tube 3 and is located inside the middle section of the support frame 1. The air floating bearing 4 includes an air floating bushing mounting seat 41, an air floating bushing 42, an air floating bushing fixing plate 43, and an air floating bushing mounting flange 44. An air floating bushing mounting flange 44 is installed at the lower part of the air floating bushing mounting seat 41 and is fixedly installed on the top of the fixing plate 33 of the guiding tube 3 through the air floating bushing mounting flange 44. An air inlet 411 and a drain outlet 412 are also provided at the lower part of the air floating bushing mounting seat 41. There are two air floating bushings 42, which are respectively installed on the inner sides of the upper and lower ends of the air floating bushing mounting seat 41. The air floating bushing fixing plate 43 is horizontally installed on the upper part of the air floating bushing mounting seat 41. The bottom of the middle section is fixed to the upper part of the air floating bushing mounting seat 41, and the two ends are respectively fixed to the upper parts of the middle sections of the two second cross beams 122 on the opposite sides of the middle section of the support frame 1; the entire air floating bearing 4 can be installed on the second cross beam 122 of the support frame 1 through the air floating bushing fixing plate 43.

[0046] The control rod 5 is vertically installed at the upper part of the air bearing 4 and is located inside the upper end of the support frame 1. It includes a control rod main body 51 and a clamping sling 52. The lower end of the control rod main body 51 moves downward through the middle of the air bearing sleeve fixing plate 43 of the air bearing 4 and then inserts into the inner side of the air bearing sleeve 42 of the air bearing 4. The upper end of the control rod main body 51 moves through the top plate 13 of the support frame 1 and extends upward above the top plate 13. The control rod main body 51 can move up and down within the air bearing sleeve 42. The clamping sling 52 is screwed tightly to one end of the control rod main body 51 that extends upward above the top plate 13. The gap between the control rod 5 and the air bearing 4 is only a few micrometers, so the control rod 5 will not have lateral displacement. After adjusting vertically, the control rod 5 can fall vertically. The control rod main body 51 can adjust its own weight and stiffness by changing the material.

[0047] As Figures 9 to 11 shown, the clamping mechanism 6 is arranged at the center of the top surface of the top plate 13 of the support frame 1. It includes a mounting plate 61, a moving guide rail 62, a slider 63, a clamping plate 64, a servo motor 65 and a position sensing switch 66.

[0048] The mounting plate 61 is fixedly installed at the center of the top surface of the top plate 13 of the support frame 1.

[0049] The moving guide rail 62 is fixedly installed on the mounting plate 61. It includes a main moving guide rail 621 and a secondary moving guide rail 622 that are arranged in parallel and symmetrically on the top surface of the mounting plate 61.

[0050] The slider 63 is slidably installed on the moving guide rail 62. It has a pair and is respectively slidably installed at both ends of the secondary moving guide rail 622.

[0051] The clamping plate 64 is fixedly installed on the slider 63. It includes a first clamping plate 641 and a second clamping plate 642. One end of the bottom of the first clamping plate 641 is slidably installed on the upper part of one end of the main moving guide rail 621, and the other end is fixed to the upper part of the slider 63 at one end of the secondary moving guide rail 622. One end of the bottom of the second clamping plate 642 is slidably installed on the upper part of the other end of the main moving guide rail 621, and the other end is fixed to the upper part of the slider 63 at the other end of the secondary moving guide rail 622.

[0052] The servo motor 65 is installed at one end of the main moving guide rail 621. Its power output end is connected to the sliders 63 at both ends of the secondary moving guide rail 622 through a lead screw nut pair. The clamping mechanism 6 can use the servo motor 65 to grasp and release the control rod 5, achieving no delay and accurately measuring the rod dropping process.

[0053] The position sensing switch 66 has a pair and is respectively and correspondingly installed on the outer sides of the middle section guide rail and the guide rail near one end of the servo motor 65 of the main moving guide rail 621, used to limit the movement range of the clamping plate 64. The clamping mechanism 6 is installed on the top plate 13 of the support frame 1 through the mounting plate 61.

[0054] The gas circuit unit 7 includes an air pump 71 and an air supply pipeline 72; the air pump 71 is connected to the air bearing sleeve 42 of the air bearing 4 through the air supply pipeline 72 to supply high-pressure gas to the air bearing 4. The high-pressure gas generated by the air pump 71 forms an air film between the air bearing sleeve 42 and the control rod main body 51, so that there is no contact between the air bearing 4 and the control rod 5, and no additional resistance is brought.

[0055] The measurement unit 8 includes a measurement terminal 81, a high-speed mobile tracking camera measuring instrument 82, a wire rope displacement sensor 83, an impact force sensor 84, a pore water pressure sensor 85, and a particle image velocimetry instrument 86. Among them, the measurement terminal 81 has a data acquisition card, and the data acquisition card is respectively connected to the high-speed mobile tracking camera measuring instrument 82, the wire rope displacement sensor 83, the impact force sensor 84, the pore water pressure sensor 85, and the particle image velocimetry instrument 86 through data lines. The high-speed mobile tracking camera measuring instrument 82 is erected outside the experimental device; the wire rope displacement sensor 83 is installed on the top of the top plate 13 of the support frame 1; the impact force sensor 84 and the pore water pressure sensor 85 are installed on the position adjustment plate 32 at the bottom end of the guide pipe 3; the particle image velocimetry instrument 86 is erected outside the experimental device.

[0056] As Figure 12 shown, the method for simulating eccentric rod dropping of the reactor control rod of the present invention specifically includes the following steps:

[0057] S001. Adjust the leveling plate 2 to be horizontal, and adjust so that the guide pipe 3, the air bearing 4, and the control rod 5 are vertical;

[0058] S002. Apply multiple known and definite displacement values to the control rod 5, and record the corresponding voltage values of the wire rope displacement sensor 83. Determine the calibration coefficient of the wire rope displacement sensor 83 according to the displacement values and the voltage values;

[0059] S003. Calibrate the high-speed mobile tracking camera measuring instrument 82;

[0060] S004. Adjust the horizontal position of the guide pipe so that the distance between the guide pipe 3 and the control rod 5 reaches the experimental predetermined eccentricity, lift the control rod 5 to a predetermined height and clamp it through the clamping mechanism 6;

[0061] S005. Add water or other experimental fluids into the guide tube 3 to a predetermined height, release the clamping mechanism 6 to release the control rod 5 so that it falls vertically, and synchronously measure the falling process of the control rod 5, pore water pressure, impact force of the control rod 5 hitting the bottom, and flow field structure;

[0062] S006. For the seismic condition, install the experimental device on the shaking table, adjust the vibration parameters of the shaking table (including parameters such as frequency, amplitude, acceleration, etc.), and repeat the aforementioned steps S004 and S005 to simulate the seismic condition.

[0063] In the above step S002, the calibration coefficient of the rope displacement sensor 83 is determined according to the displacement value and voltage value. Specifically, the displacement value and voltage value are fitted (that is, the one-to-one correspondence between displacement and voltage is established by using the least square method) to obtain the calibration coefficient of the rope displacement sensor 83.

[0064] Among them, the image data of the falling position of the control rod measured by the high-speed mobile tracking camera measuring instrument 82, the time history data of the falling of the control rod measured by the rope displacement sensor 83, the impact force data measured by the impact force sensor 84, the pore water pressure data measured by the pore water pressure sensor 85, and the flow field data measured by the particle image velocimetry 86 are all synchronously measured through the self-developed fluid-structure-soil coupling multi-physical parameter synchronous test and real-time monitoring system, which is convenient for fluid-structure coupling analysis.

[0065] In the above step S006, installing the experimental device on the shaking table can study the simulation of the falling rod under various seismic conditions.

[0066] To illustrate the eccentric falling rod simulation method of the reactor control rod of the present invention, as Figure 7 shown, the following embodiments are provided:

[0067] Embodiment 1

[0068] The eccentric falling rod simulation method of the reactor control rod in Embodiment 1 of the present invention specifically includes the following steps:

[0069] S101. Install the leveling plate 2 on the self-leveling ground, adjust the leveling plate 2 to be horizontal, and adjust so that the guide tube 3, air bearing 4, and control rod 5 are vertical;

[0070] S102. Apply multiple known determined displacement values to the control rod 5, record the corresponding voltage values of the rope displacement sensor 83, and determine the calibration coefficient of the rope displacement sensor 83 according to the displacement value and voltage value;

[0071] S103. Calibrate the high-speed mobile tracking camera measuring instrument 82, and its basic operations are as follows: a. Use a standard calibration plate, place it at different positions and angles in front of the high-speed mobile tracking camera measuring instrument 82, and take pictures; b. Calibrate the high-speed mobile tracking camera measuring instrument 82 using the above-mentioned pictures.

[0072] S104. Adjust the horizontal position of the guide tube 3 so that the distance between the guide tube 3 and the control rod 5 reaches the predetermined eccentricity of the experiment, lift the control rod 5 to the predetermined height and clamp it through the clamping mechanism 6.

[0073] S105. Add water or other experimental fluids to the guide tube 3 to the predetermined height, loosen the clamping mechanism 6 to release the control rod 5 so that it falls vertically, and synchronously measure the falling process of the control rod 5, the pore water pressure, the impact force of the control rod 5 hitting the bottom, and the flow field structure.

[0074] Embodiment 2

[0075] The method for simulating the eccentric dropping of the reactor control rod in Embodiment 2 of the present invention specifically includes the following steps:

[0076] S201. Install the leveling plate 2 on the vibration table, adjust the leveling plate 2 to be horizontal, and adjust so that the guide tube 3, the air floating bearing 4, and the control rod 5 are vertical. [[ID=1,]]

[0077] S202. Apply multiple known determined displacement values to the control rod 5, and record the corresponding voltage values of the rope displacement sensor 83. Determine the calibration coefficient of the rope displacement sensor 83 according to the displacement values and the voltage values.

[0078] S203. Calibrate the high-speed mobile tracking camera measuring instrument 82, and its basic operations are as follows: a. Use a standard calibration plate, place it at different positions and angles in front of the high-speed mobile tracking camera measuring instrument 82, and take pictures; b. Calibrate the high-speed mobile tracking camera measuring instrument 82 using the above-mentioned pictures.

[0079] S204. Adjust the horizontal position of the guide tube 3 so that the distance between the guide tube 3 and the control rod 5 reaches the predetermined eccentricity of the experiment, lift the control rod 5 to the predetermined height and clamp it through the clamping mechanism 6.

[0080] S205. Add water or other experimental fluids to the guide tube 3 to the predetermined height.

[0081] S206. Adjust parameters such as the frequency, amplitude, and acceleration of the vibration table.

[0082] S207. Loosen the clamping mechanism 6 to release the control rod 5 so that it falls vertically, and synchronously measure the falling process of the control rod 5, the pore water pressure, the impact force of the control rod 5 hitting the bottom, and the flow field structure.

[0083] The present invention can study the process of the reactor control rod dropping, the dropping time, the pore water pressure, the flow field, the hydrodynamic characteristics, and the dropping impact force of the control rod. It can accurately adjust and control the eccentricity, realizing the simulation of eccentric rod dropping. The results can provide a scientific basis for engineers to design and install control rod drive mechanisms, etc.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An experimental device for eccentric rod drop of a reactor control rod, characterized in that : The experimental device includes a support frame, a leveling plate, a guide tube, an air bearing, a control rod, a clamping mechanism, an air circuit unit, and a measurement unit; The leveling plate is horizontally arranged, and the support frame is vertically and fixedly installed on the upper part of the leveling plate in a matching manner; the guide tube is vertically installed on the top surface of the leveling plate in a matching manner; the air bearing is installed on the upper part of the guide tube in a matching manner; the control rod is vertically installed on the upper part of the air bearing in a matching manner; the clamping mechanism is arranged on the top of the support frame in a matching manner; the air circuit unit and the measurement unit are located outside the support frame and are connected to the air bearing through an air supply pipeline; The measurement unit includes a measurement terminal and a high-speed mobile tracking camera measuring instrument, a wire displacement sensor, an impact force sensor, a pore water pressure sensor, and a particle image velocimetry instrument connected to the measurement terminal through a data line; the high-speed mobile tracking camera measuring instrument is installed outside the experimental device; the wire displacement sensor is installed on the top of the support frame in a matching manner; the impact force sensor and the pore water pressure sensor are installed at the bottom end of the guide tube in a matching manner; the particle image velocimetry instrument is installed outside the experimental device; The air bearing is located inside the middle section of the support frame and includes an air bearing sleeve mounting seat, an air bearing sleeve, an air bearing sleeve fixing plate, and an air bearing sleeve mounting flange; The lower part of the air bearing sleeve mounting seat is provided with the air bearing sleeve mounting flange and is fixedly installed on the top of the guide tube through the air bearing sleeve mounting flange; the air bearing sleeves are installed on the inner sides of the upper and lower ends of the air bearing sleeve mounting seat in a matching manner; the air bearing sleeve fixing plate is horizontally installed on the upper part of the air bearing sleeve mounting seat and is fixedly connected to the support frame at both ends; The leveling plate includes a first leveling plate arranged horizontally and a second leveling plate horizontally and fixedly installed at the center of the top surface of the first leveling plate in a matching manner; the second leveling plate is also vertically provided with leveling plate threaded holes along the circumferential edge area, and the levelness of the second leveling plate can be adjusted by screwing a screw rod into the leveling plate threaded holes; The guide tube is located inside the support frame and includes a guide tube main body, a position adjustment plate horizontally and fixedly fixed at the bottom end of the guide tube main body, and a fixing plate horizontally and fixedly fixed at the top end of the guide tube main body; the position adjustment plate is fixedly installed on the top surface of the second leveling plate, and through grooves vertically penetrating are symmetrically opened in the relative two side areas of the position adjustment plate; the position adjustment plate can be slid back and forth to adjust its lateral position on the second leveling plate through the through grooves.

2. The experimental device for eccentric rod drop of the reactor control rod according to claim 1, characterized in that : The lower part of the air bearing sleeve mounting seat is also provided with an air inlet and a drain outlet.

3. The reactor control rod eccentric drop rod experimental device according to claim 1, characterized in that : The air circuit unit includes an air pump and the air supply pipeline; the air pump is connected to the air bearing sleeve through the air supply pipeline.

4. The reactor control rod eccentric drop rod experimental device according to claim 1, characterized in that: The control rod is located inside the upper end of the support frame and includes a control rod body and a clamping sling; the lower end of the control rod body passes through the air-floating bushing fixing plate and then inserts into the inner side of the air-floating bushing; the upper end of the control rod body extends above the top of the support frame and a clamping sling is installed in a matching manner at the extending end; the control rod body can move up and down within the air-floating bushing.

5. The experimental device for eccentric rod drop of the reactor control rod according to claim 1, characterized in that: The clamping mechanism includes a mounting plate, a moving guide rail, a slider, a clamping plate, a servo motor and a position induction switch; the mounting plate is fixedly installed on the top of the support frame in a matching manner; the moving guide rail is fixedly installed on the top surface of the mounting plate in a matching manner; the slider is slidably installed on the moving guide rail in a matching manner; the clamping plate is fixedly installed on the slider in a matching manner; the servo motor is installed at one end of the moving guide rail in a matching manner, and its power output end is connected to the slider in a matching manner through a lead screw-nut pair; the position induction switch is installed on the moving guide rail in a matching manner.

6. A simulation method for eccentric rod drop of a reactor control rod, based on the reactor control rod eccentric rod drop experimental device according to any one of claims 1 to 5 above, characterized in that, The simulation method mainly includes the following steps: (1) Adjust the leveling plate of the experimental device to be horizontal, and adjust so that the guide tube, the air-floating bearing and the control rod of the experimental device are kept vertical; (2) Apply multiple known definite displacement values to the control rod of the experimental device, record the corresponding voltage values of the wire displacement sensor of the measurement unit of the experimental device, and then determine the calibration coefficient of the wire displacement sensor according to the displacement values and the voltage values; (3) Calibrate the high-speed mobile tracking camera measuring instrument of the experimental device; (4) Adjust the horizontal position of the guide tube of the experimental device so that the distance between the guide tube and the control rod of the experimental device reaches the predetermined eccentricity of the experiment. After lifting the control rod of the experimental device to a predetermined height, clamp it through the clamping mechanism of the experimental device; (5) Add experimental fluid to the guide tube of the experimental device until it reaches the predetermined height, loosen the clamping mechanism of the experimental device to release the control rod of the experimental device and let it fall vertically, and synchronously measure the falling process of the control rod of the experimental device, the pore water pressure, the impact force of the control rod hitting the bottom and the flow field structure; (6) For the earthquake condition, install the experimental device on the shaking table, adjust the vibration parameters of the shaking table, and repeat the above steps (4) and (5) to simulate the earthquake condition.

7. The eccentric rod-drop simulation method of the reactor control rod according to claim 6, characterized in that In the step (2), determining the calibration coefficient of the wire displacement sensor according to the displacement values and the voltage values specifically means: fitting the displacement values and the voltage values to obtain the calibration coefficient of the wire displacement sensor.

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