System and method for measuring underwater size of heavy water reactor fuel rod bundle

Abstract

The invention relates to the technical field of fuel rod bundle underwater size measurement, and provides a heavy water reactor fuel rod bundle underwater size measurement system and method. The heavy water reactor fuel rod bundle underwater dimension measurement system comprises a supporting platform; a rotary positioning mechanism; a three-dimensional moving mechanism; the first underwater measurement camera is used for collecting an overall image of the fuel rod bundle and an image of a single fuel element; the camera measurement calibration platform comprises a rod bundle measurement calibration plate and an element measurement calibration plate; the first reflector assembly is used for reflecting the image of the first end plate to the first underwater measurement camera; the camera movement module comprises two module guide rails and a camera bracket capable of sliding along the module guide rails; the second underwater measurement camera is used for acquiring an image of the second end plate; and the second reflector assembly is used for reflecting the image of the second end plate to the second underwater measurement camera. Fuel rod bundle image acquisition and splicing can be completed through the mobile platform and the underwater camera, the detection speed is high, and the measurement precision is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel bundle underwater size measurement, in particular to a heavy water reactor fuel bundle underwater size measurement system and method. BACKGROUND

[0002] CANDU type heavy water reactor nuclear power plant is a pressure tube type reactor core, using heavy water as moderator and coolant, using natural uranium as fuel, adopting non-stop refueling, and having very high economic efficiency and additional application value. The fuel bundle is a core fuel component of the CANDU type heavy water reactor, which has a simple and compact structure.

[0003] After the heavy water reactor fuel bundle is discharged from the reactor, the length of the fuel bundle, the bending degree of the fuel bundle, the length of the fuel element, the spacing between the fuel elements, and the diameter of the end plate need to be measured underwater in time. These data are important basis for performance analysis of the fuel bundle after discharge from the reactor, and performance analysis and evaluation is a key link for research and development of heavy water reactor fuel zirconium materials and new cladding materials.

[0004] Therefore, how to realize underwater accurate measurement of the length of the fuel bundle, the bending degree of the fuel bundle, the length of the fuel element, the spacing between the fuel elements, and the diameter of the end plate has become a technical challenge to be solved. SUMMARY

[0005] In order to solve the above technical problems of underwater accurate measurement of the length of the fuel bundle, the bending degree of the fuel bundle, the length of the fuel element, the spacing between the fuel elements, and the diameter of the end plate, the first aspect of the present application provides a heavy water reactor fuel bundle underwater size measurement system.

[0006] The second aspect of the present application further provides a heavy water reactor fuel bundle underwater size measurement method.

[0007] In view of the above, the first aspect of the present application provides a heavy water reactor fuel bundle underwater size measurement system, the fuel bundle comprising a plurality of fuel elements and first and second end plates arranged at both ends of the fuel elements, the heavy water reactor fuel bundle underwater size measurement system comprising: a support platform; a rotating positioning mechanism arranged on the support platform and used for clamping and driving the fuel bundle to rotate; a three-dimensional moving mechanism arranged on the support platform; a first underwater measurement camera arranged on the three-dimensional moving mechanism and driven by the three-dimensional moving mechanism to move in a three-dimensional space, and used for collecting an overall image of the fuel bundle and an image of a single fuel element; a camera measurement calibration platform arranged on the support platform and comprising a bundle measurement calibration plate and an element measurement calibration plate; a first mirror assembly arranged on the support platform and used for reflecting an image of the first end plate to the first underwater measurement camera; a camera movement module arranged on the support platform and comprising two module guide rails and a camera support that can slide along the module guide rails; a second underwater measurement camera arranged on the camera support and used for collecting an image of the second end plate; and a second mirror assembly arranged on the camera support and used for reflecting the image of the second end plate to the second underwater measurement camera.

[0008] In combination with the first aspect, in some implementable manners, the camera movement module further comprises: a connecting bottom plate and a lead screw transmission mechanism; the connecting bottom plate is arranged on the support platform, and the two module guide rails are arranged side by side on two sides of the connecting bottom plate; the lead screw transmission mechanism comprises a lead screw, a lead screw support, an underwater motor and a lead screw nut, the lead screw support is arranged on the connecting bottom plate, one end of the lead screw is connected with the underwater motor through a shaft coupling, the other end of the lead screw is supported by the lead screw support, the lead screw is located between the two module guide rails, the lead screw nut is connected with the camera support, and the camera support is in sliding fit with the module guide rails through a module sliding block.

[0009] In combination with the first aspect, in some implementable manners, the first mirror assembly comprises: a mirror support arranged on the support platform; and an end plate mirror embedded in the mirror support at a preset angle.

[0010] In combination with the first aspect, in some implementable manners, the camera measurement calibration platform further comprises: a mounting leg arranged on the support platform, and the bundle measurement calibration plate is arranged on the mounting leg and fixed by a pressing plate; and a support seat arranged on the pressing plate, and the element measurement calibration plate is arranged on the support seat and fixed by a pressing strip.

[0011] In combination with the first aspect, in some implementable manners, the upper surface of the bundle measurement calibration plate is provided with a black-and-white checkered pattern, and the upper surface height of the bundle measurement calibration plate is flush with the center line of the fuel bundle; and the upper surface of the element measurement calibration plate is provided with a black-and-white checkered pattern, and the upper surface height of the element measurement calibration plate is flush with the center line of the top fuel element of the fuel bundle.

[0012] The second aspect of the application provides a method for measuring the underwater size of a heavy water reactor fuel rod bundle, which adopts the underwater heavy water reactor fuel rod bundle size measurement system according to any one of the preceding aspects, and includes the following steps: fixing the fuel rod bundle on an underwater rotating station; driving the first underwater measurement camera to move to the calibration plate area for camera calibration to obtain a pixel conversion coefficient; rotating the fuel rod bundle to a first angle, driving the first underwater measurement camera to move along the axial direction of the fuel rod bundle, and segmentally collecting rod bundle overall images; splicing and edge extraction are performed based on the segmented images to calculate the length and curvature of the fuel rod bundle at the first angle; the fuel rod bundle is rotated to a plurality of different angles, and the above image collection and calculation steps are repeated to complete multi-angle size measurement; the first underwater measurement camera is driven to move to the calibration plate area for re-calibration of the calibration plate; for each fuel element of the outer circle of the fuel rod bundle, the rod bundle is rotated in turn and the first underwater measurement camera is driven to move along the axial direction of the element, and single fuel element images are segmentally collected to calculate the length and spacing of each fuel element; the first end plate image of the fuel rod bundle is reflected to the first underwater measurement camera through the first mirror assembly for image collection and diameter measurement; the second end plate image of the fuel rod bundle is reflected to the second underwater measurement camera through the second mirror assembly for image collection and diameter measurement.

[0013] In combination with the second aspect, in some implementable manners, driving the first underwater measurement camera to move to the calibration plate area for camera calibration to obtain a pixel conversion coefficient includes: driving the first underwater measurement camera to move above the rod bundle measurement calibration plate; adjusting the height of the first underwater measurement camera so that the field of view thereof completely covers the rod bundle measurement calibration plate; collecting an image of the rod bundle measurement calibration plate, performing correction processing on the image, and calculating to obtain a pixel conversion coefficient to complete rod bundle measurement calibration.

[0014] In combination with the second aspect, in some implementable manners, driving the first underwater measurement camera to move to the calibration plate area for re-calibration of the calibration plate includes: driving the first underwater measurement camera to move above the element measurement calibration plate; adjusting the height of the first underwater measurement camera so that the field of view of the first underwater measurement camera completely covers the element measurement calibration plate; collecting an image of the element measurement calibration plate, performing image correction processing, and calculating to obtain a pixel conversion coefficient to complete calibration for fuel element measurement.

[0015] In combination with the second aspect, in some implementable manners, the fuel rod bundle first end plate image is reflected to the first underwater measurement camera by the first mirror assembly, image acquisition and diameter measurement are performed, and the following steps are included: starting the rotary positioning mechanism, clamping and positioning the fuel rod bundle, and then releasing the two end positionings; starting the three-dimensional movement mechanism, moving the first underwater measurement camera to be directly above the end plate mirror, so that the first underwater measurement camera picture covers the entire fuel rod bundle first end plate; starting the first underwater measurement camera software system, completing the fuel rod bundle first end plate image acquisition and edge extraction; operating the first underwater measurement camera software system, completing the fuel rod bundle first end plate appearance inspection and diameter measurement.

[0016] In combination with the second aspect, in some implementable manners, the fuel rod bundle second end plate image is reflected to the second underwater measurement camera by the second mirror assembly, image acquisition and diameter measurement are performed, and the following steps are included: driving the second underwater measurement camera to move horizontally, so that its field of view covers the second end plate of the fuel rod bundle; acquiring the reflected image of the second end plate and performing edge extraction processing; based on the extracted edge features, completing the appearance inspection and diameter measurement of the second end plate.

[0017] Compared with the related art, the present application has the following technical effects: The heavy water reactor fuel rod bundle underwater size measurement system and process method provided by the present application can complete fuel rod bundle image acquisition and splicing by using a mobile platform and an underwater camera, and then complete size measurement by edge extraction and pixel conversion, so that the detection speed is fast, the measurement precision is high, the image can be traced back at any time, the system is highly automated and integrated, and operation is convenient and fast.

[0018] Specifically, underwater photographing and image acquisition of the fuel rod bundle at any angle surface and two side end plates can be implemented; accurate movement positioning of the underwater camera can be implemented, and seamless splicing of the acquired images can be completed by segmented photographing at the accurate positions; photographing and image acquisition of the two side end plates of the fuel rod bundle can be completed by the two underwater cameras through the mirror form; length measurement and bending degree measurement of the fuel rod bundle at any angle can be implemented; length measurement and spacing measurement of the 18 fuel elements of the outer circle of the fuel rod bundle can be implemented; appearance inspection and diameter measurement of the two side end plates of the fuel rod bundle can be implemented.

[0019] Additional aspects and advantages of the present application will become apparent from the following description part, or be understood by practicing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 A structure schematic diagram of a heavy water reactor fuel rod bundle underwater size measurement system in one embodiment of the present application is shown. Figure 2 A structural schematic diagram of an underwater inspection platform in an embodiment of the present application is shown; Figure 3 A structural schematic diagram of a first underwater measurement camera in an embodiment of the present application is shown; Figure 4 A structural schematic diagram of a camera movement module in an embodiment of the present application is shown; Figure 5 A structural schematic diagram of a camera measurement calibration platform in an embodiment of the present application is shown; Figure 6 A structural schematic diagram of a first mirror assembly in an embodiment of the present application is shown; Figure 7 A structural schematic diagram of a fuel rod bundle in an embodiment of the present application is shown; Figure 8 A structural schematic diagram of a second end plate of a fuel rod bundle in an embodiment of the present application is shown; Figure 9 A structural schematic diagram of a rotary positioning mechanism in an embodiment of the present application is shown; Figure 10 A structural schematic diagram of a rotary positioning mechanism in an embodiment of the present application is shown; Figure 11 A structural schematic diagram of a rotary positioning mechanism in an embodiment of the present application is shown; Figure 12 A structural schematic diagram of a rotary positioning mechanism in an embodiment of the present application is shown; Figure 13 A structural schematic diagram of a rod bundle measurement process flow in an embodiment of the present application is shown; Figure 14 A structural schematic diagram of an end plate measurement process flow in an embodiment of the present application is shown; Figure 15 A structural schematic diagram of a heavy water reactor fuel rod bundle underwater size measurement method in an embodiment of the present application is shown.

[0021] Wherein, Figures 1 to 12 The correspondence between the reference signs and the component names in the accompanying drawings is as follows: 1 underwater inspection platform, 2 mounting support, 3 first underwater measurement camera, 4 camera movement module, 5 second underwater measurement camera, 6 camera measurement calibration platform, 7 first mirror assembly, 8 fuel rod bundle; 101 three-dimensional movement mechanism, 102 rotary positioning mechanism, 103 support platform; 301 servo motor, 302 worm box, 303 first worm, 304 first turbine, 305 first universal joint, 306 first transmission rod, 307 second universal joint, 308 second transmission rod, 309 bottom plate, 310 third universal joint, 311 second worm, 312 worm seat, 313 second turbine, 314 fourth universal joint, 315 turbine seat, 316 first special-shaped worm, 317 second special-shaped worm, 318 fuel rod bundle support, 319 underwater DC motor, 320 shaft coupling, 321 transmission screw, 322 transmission nut, 323 screw support, 324 connecting rod, 325 pressing connecting rod, 326 pressing disc, 327 first tension and pressure sensor, 328 limiting rod, 329 rod bundle limiting block support, 330 square head, 331 gear, 332 gear screw, 333 rod bundle limiting block, 334 limiting block sliding shaft; 401 connecting bottom plate, 402 module guide rail, 403 module sliding block, 404 motion support plate, 405 underwater motor, 406 shaft coupling, 407 lead screw, 408 lead screw support, 409 camera support, 410 end plate mirror; 601 installation leg, 602 rod bundle measurement calibration plate, 603 pressing plate, 604 support seat, 605 element measurement calibration plate, 606 pressing strip; 701 mirror support, 702 end plate mirror, 703 mirror pressing strip; 801 fuel element, 802 support pad, 803 second end plate. DETAILED DESCRIPTION

[0022] In order to enable the above-mentioned purposes, features and advantages of the present application to be more clearly understood, the present application will be further described below with reference to the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0023] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0024] The following refers to Figures 1 to 15 The heavy water reactor fuel rod bundle underwater size measurement system and measurement method according to some embodiments of the present application are described.

[0025] As Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8As shown, the first aspect of the present application provides a heavy water reactor fuel bundle underwater size measurement system, the fuel bundle 8 includes a plurality of fuel elements 801 and first and second end plates 803 arranged at both ends of the fuel elements 801, and the heavy water reactor fuel bundle underwater size measurement system comprises: a support platform 103; a rotary positioning mechanism 102 arranged on the support platform 103 and used for clamping and driving the fuel bundle 8 to rotate; a three-dimensional movement mechanism 101 arranged on the support platform 103; a first underwater measurement camera 3 arranged on the three-dimensional movement mechanism 101 and driven by the three-dimensional movement mechanism 101 to move in a three-dimensional space, and used for collecting overall images of the fuel bundle 8 and images of single fuel elements 801; a camera measurement calibration platform 6 arranged on the support platform 103 and comprising a bundle measurement calibration plate 602 and an element measurement calibration plate 605; a first mirror assembly 7 arranged on the support platform 103 and used for reflecting images of the first end plate to the first underwater measurement camera 3; a camera movement module 4 arranged on the support platform 103 and comprising two module guide rails 402 and a camera bracket 409 which can slide along the module guide rails 402; a second underwater measurement camera 5 arranged on the camera bracket 409 and used for collecting images of the second end plate 803; and a second mirror assembly arranged on the camera bracket 409 and used for reflecting images of the second end plate 803 to the second underwater measurement camera 5.

[0026] The heavy water reactor fuel bundle underwater size measurement system provided by the present application comprises the support platform 103, the rotary positioning mechanism 102, the three-dimensional movement mechanism 101, the first underwater measurement camera 3, the camera measurement calibration platform 6, the first mirror assembly 7, the camera movement module 4, the second underwater measurement camera 5 and the second mirror assembly.

[0027] By arranging the first underwater measurement camera 3 to collect overall images of the fuel bundle 8 and images of single fuel elements 801, and the second underwater measurement camera 5 to collect images of the second end plate 803, and by arranging the first and second mirror assemblies to reflect images of the first and second end plates 803 to corresponding cameras respectively, information of different parts of the fuel bundle 8 can be comprehensively obtained, underwater accurate measurement of multiple key dimensions such as the length of the fuel bundle 8, the curvature of the fuel bundle 8, the length of the fuel elements 801, the spacing between the fuel elements 801, and the diameter of the end plate can be realized, and the problem that the traditional method is difficult to comprehensively and accurately measure can be effectively solved.

[0028] The rotary positioning mechanism 102 can clamp and drive the fuel bundle 8 to rotate, the three-dimensional movement mechanism 101 can drive the first underwater measurement camera 3 to move in a three-dimensional space, and the camera bracket 409 can slide along the module guide rails 402, so that the measurement system has high flexibility and adjustability, can flexibly adjust the measurement position and angle according to different measurement requirements and the actual state of the fuel bundle 8, and ensures the accuracy and reliability of the measurement data.

[0029] The camera measurement calibration platform 6 is provided with a rod bundle measurement calibration plate 602 and an element measurement calibration plate 605, and can accurately calibrate the measurement camera, eliminate the influence of the camera itself and the measurement environment on the measurement results, further improve the measurement accuracy and stability, and ensure the accuracy and consistency of the measurement data.

[0030] The first underwater measurement camera 3 and the second underwater measurement camera 5 are provided with image processing software, and the segmented images can be spliced.

[0031] As Figure 9 , Figure 10 , Figure 11 and Figure 12As shown, the rotating positioning mechanism 102 comprises a rotating shaft waterproof servo motor 301, a worm box 302, a first worm 303, a first worm wheel 304, a first universal joint 305, a first transmission rod 306, a second universal joint 307, a second transmission rod 308, a bottom plate 309, a third universal joint 310, a second worm 311, a worm shaft 312, a second worm wheel 313, a fourth universal joint 314, a worm wheel seat 315, a first special-shaped worm 316, a second special-shaped worm 317, a fuel rod bundle support 318, an underwater DC motor 319, a shaft coupling 320, a transmission screw 321, a transmission nut 322, a screw support 323, a connecting rod 324, a pressing connecting rod 325, a pressing disc 326, a first tension and pressure sensor 327, a limiting rod 328, a rod bundle limiting block support 329, a square head 330, a gear 331, a gear screw 332, a rod bundle limiting block 333, and a limiting block sliding shaft 334. The rotating shaft waterproof servo motor 301 is connected to the first worm 303 through a shaft coupling and is installed on the worm box 302. The worm box 302 drives the first worm 303 to rotate in the worm box 302, and the first worm wheel 304 is engaged with the first worm 303. One end of the first transmission rod 306 is connected to the first worm wheel 304 through the first universal joint 305, and the other end is connected to the second worm 311 through the third universal joint 310. The second worm 311 is installed in the worm shaft 312 and is engaged with the second worm wheel 313. The second worm wheel 313 is connected to the second special-shaped worm 317 through a transmission key, and the other end of the second special-shaped worm 317 is connected to the first special-shaped worm 316 through the fourth universal joint 314. The two special-shaped worm wheels are supported by the worm wheel seat 315, and the worm wheel seat 315 is installed on the fuel rod bundle support 318 through screws. One end of the second transmission rod 308 is connected to the second worm 311 through the second universal joint 307, and the other end is connected to the symmetrically installed special-shaped worm wheel combination. The two fuel rod bundle supports 318 are symmetrically installed on the bottom plate 309. When the rotating shaft waterproof servo motor 301 rotates, the symmetrically installed special-shaped worm wheels, the first special-shaped worm 316, and the second special-shaped worm 317 are simultaneously rotated through worm and worm wheel engagement transmission and two universal joint transmission rods. The first special-shaped worm 316 and the second special-shaped worm 317 are engaged with the support pad 802 in the fuel rod bundle 8, driving the fuel rod bundle 8 to rotate around the shaft center. The underwater DC motor 319 is connected to one end of the transmission screw 321 through the shaft coupling 320, the other end of the transmission screw 321 is supported on the screw support 323, the transmission nut 322 is engaged on the transmission screw 321 and is connected to the pressing connecting rod 325 through a hinge, the middle of the pressing connecting rod 325 is connected to the connecting rod 324 through a hinge, the pressing disc 326 is installed on the first tension and pressure sensor 327 through screws, the first tension and pressure sensor 327 is installed on the pressing connecting rod 325 through screws at the bottom, and the limiting rod 328 is installed on both sides of the screw support 323.When the underwater DC motor 319 rotates, it can drive the pressing connecting rod 325 to make pitching motion, so as to realize clamping and loosening of one side end plate of the fuel rod bundle 8 by the pressing disc 326, the first tensile and compressive force sensor 327 feeds back the pressure value in real time when clamping, and the system stops running when the pressure exceeds the limit value, thereby playing a protection role. When the pressing disc 326 is loosened, the limiting rod 328 plays a limiting role to prevent the connecting rod mechanism from reaching the dead point position. The rod bundle limiting block 333 is sleeved on the limiting block sliding shaft 334 and the gear screw rod 332, the lower gear of the gear screw rod 332 is engaged with the gear 331, the limiting block sliding shaft 334 and the gear screw rod 332 are supported on the rod bundle limiting block support 329, the square head 330 is connected with the gear 331 through a key, and when the square head 330 is rotated through a sleeve tool, the rod bundle limiting block 333 can be lifted. When the rod bundle limiting block 333 is lifted, the rod bundle limiting block 333 clamps one side end plate of the fuel rod bundle 8, and the other side end plate is limited by the rod bundle limiting block 333, and the limiting is cancelled after the rod bundle limiting block 333 is lowered.

[0032] The three-dimensional moving mechanism 101 includes an X-axis moving module, a Y-axis moving module and a Z-axis moving module, and realizes independent and flexible movement in three orthogonal directions. The equipment installed thereon can be accurately positioned in three-dimensional space, meets the demand of detecting different positions of the fuel rod bundle, and is more convenient and accurate in horizontal and vertical movement adjustment, thereby improving the flexibility of operation and the comprehensiveness of detection.

[0033] The underwater size measurement system for the heavy water reactor fuel rod bundle provided in the application is designed for underwater environment, and each component can normally work underwater, thereby overcoming the difficulty caused by the complex underwater environment to measurement, and providing a reliable technical means for size measurement of the heavy water reactor fuel rod bundle 8 in underwater state. The three-dimensional moving mechanism 101, the first underwater measurement camera 3 and the second underwater measurement camera 5 can complete image acquisition and splicing of the fuel rod bundle 8, and then size measurement is completed through edge extraction and pixel conversion, the detection speed is fast, the measurement precision is high, the image can be traced back at any time, the system is high in automation and integration degree, and the operation is convenient and fast.

[0034] As Figure 4As shown, in some embodiments provided in the present application, the camera motion module 4 further comprises a connecting base plate 401 and a lead screw transmission mechanism. The connecting base plate 401 is arranged on the support platform 103, and two module guide rails 402 are arranged side by side on both sides of the connecting base plate 401. The lead screw transmission mechanism comprises a lead screw 407, a lead screw support 408, an underwater motor 405 and a lead screw nut. The lead screw support 408 is arranged on the connecting base plate 401. One end of the lead screw 407 is connected to the underwater motor 405 through a shaft coupling 406, and the other end of the lead screw 407 is supported by the lead screw support 408. The lead screw 407 is located between the two module guide rails 402. The lead screw nut is connected to a camera bracket 409, and the camera bracket 409 is slidably connected to the module guide rail 402 through a module slider 403.

[0035] In this embodiment, the camera motion module 4 further comprises a connecting base plate 401 and a lead screw transmission mechanism. The cooperation of the lead screw 407 and the lead screw nut can accurately convert the rotary motion of the underwater motor 405 into linear motion, thereby driving the camera bracket 409 to make accurate linear displacement along the module guide rail 402. The accurate transmission mode of the lead screw transmission mechanism enables the second underwater measurement camera 5 to accurately reach the preset measurement position, ensuring the position accuracy of collecting the image of the second end plate 803, and thereby improving the accuracy of measuring the size of the fuel rod bundle 8.

[0036] The lead screw support 408 plays a stabilizing support role for the lead screw 407, reducing the vibration and deformation of the lead screw 407 during transmission. At the same time, the camera bracket 409 is slidably connected to the module guide rail 402 through the module slider 403, which not only ensures the smoothness of the movement of the camera bracket 409, but also effectively limits the movement direction, so that the camera bracket 409 remains stable during movement, avoiding affecting the imaging quality and measurement accuracy of the second underwater measurement camera 5 due to shaking or deviation.

[0037] The two module guide rails 402 are arranged side by side on both sides of the connecting base plate 401, and the lead screw 407 is located between the two module guide rails 402. This layout makes full use of the space, making the entire camera motion module 4 compact in structure and reasonable in layout. By controlling the operation of the underwater motor 405, the position of the camera bracket 409 can be easily adjusted, thereby changing the shooting position of the second underwater measurement camera 5. This enables the measurement system to adapt to fuel rod bundles 8 of different sizes and shapes, as well as different measurement requirements.

[0038] The connecting bottom plate 401 firmly sets the entire camera movement module 4 on the support platform 103, enhancing the stability of the module under water. Under the action of external forces such as water flow and pressure under water, the connecting bottom plate 401 can effectively resist the influence of these external forces, ensuring that the relative positions between the components of the module remain unchanged, so that the second underwater measuring camera 5 can work stably and continuously collect high-quality image data, providing a reliable basis for the size measurement of the fuel rod bundle 8.

[0039] As shown in Figure 6 In some embodiments provided by the present application, the first mirror assembly 7 includes: a mirror support 701 arranged on the support platform 103; and an end plate mirror 702 embedded in the mirror support 701 at a preset angle.

[0040] In this embodiment, the first mirror assembly 7 includes the mirror support 701 and the end plate mirror 702. The mirror support 701 is stably arranged on the support platform 103, providing reliable support for the end plate mirror 702, ensuring that it remains stable in position in a complex underwater environment and is not displaced due to water flow impact or equipment vibration, thereby guaranteeing the stability and accuracy of the reflected image. The end plate mirror 702 is embedded in the mirror support 701 at a preset angle, which can accurately reflect the image of the first end plate to the first underwater measuring camera 3, so that the camera can obtain a clear image without directly facing the end plate, optimizing the camera layout and saving underwater space. The preset angle can be 45 degrees.

[0041] The first mirror assembly 7 has a simple structure, is easy to install and maintain, reduces the overall complexity and cost of the system, and improves the reliability and durability of the system, which is helpful for long-term stable operation under water and provides strong support for accurate measurement of the related dimensions of the fuel rod bundle 8.

[0042] The second mirror assembly has a structure similar to that of the first mirror assembly 7.

[0043] As shown in Figure 5 In some embodiments provided by the present application, the camera measurement calibration platform 6 further includes: a mounting leg 601 arranged on the support platform 103, a rod bundle measurement calibration plate 602 arranged on the mounting leg 601 and fixed by a pressing plate 603; a support seat 604 arranged on the pressing plate 603, and an element measurement calibration plate 605 arranged on the support seat 604 and fixed by a pressing strip 606.

[0044] In this embodiment, the camera measurement calibration platform 6 further comprises a mounting leg 601 and a support base 604. The mounting leg 601 stably sets the rod bundle measurement calibration plate 602 on the support platform 103, providing reliable foundation support for the rod bundle measurement calibration plate 602, ensuring that it remains fixed in position in a complex measurement environment and does not shift or sway due to external interference, thereby ensuring the accuracy and stability of the calibration data.

[0045] The rod bundle measurement calibration plate 602 is fixed by a pressing plate 603. This simple and reliable fixing method can effectively prevent the calibration plate from loosening and is convenient for installation and removal. When the calibration plate needs to be maintained, replaced, or adjusted, the operator can quickly and conveniently complete the operation, improving work efficiency.

[0046] The support base 604 is provided on the pressing plate 603, and the component measurement calibration plate 605 is provided on the support base 604 and fixed by a pressing strip 606. The support base 604 can adjust the height and angle of the component measurement calibration plate 605 according to actual measurement needs, so that it better matches the measurement scene, improving the accuracy and flexibility of measurement. The fixing method of the pressing strip 606 ensures that the component measurement calibration plate 605 does not shift during measurement, ensuring the reliability of the measurement data.

[0047] The camera measurement calibration platform 6 has a reasonable structure, is convenient to install, and has high stability, and can provide an accurate calibration reference for the underwater visual detection system, effectively improving the accuracy and reliability of the size measurement of the fuel rod bundle 8.

[0048] In some embodiments provided in the present application, the upper surface of the rod bundle measurement calibration plate 602 is provided with a black and white grid pattern, and the upper surface height of the rod bundle measurement calibration plate 602 is flush with the center line of the fuel rod bundle 8. The upper surface of the component measurement calibration plate 605 is provided with a black and white grid pattern, and the upper surface height of the component measurement calibration plate 605 is flush with the center line of the top fuel component 801 of the fuel rod bundle 8.

[0049] In this embodiment, the upper surfaces of the rod bundle measurement calibration plate 602 and the component measurement calibration plate 605 are both provided with black and white grid patterns. Such patterns have high contrast and can provide clear and explicit feature points for the camera, facilitating accurate identification and positioning of the camera, effectively improving the accuracy of measurement calibration, and reducing measurement errors.

[0050] The upper surface height of the rod bundle measurement calibration plate 602 is flush with the center line of the fuel rod bundle 8, so that the camera can operate at the same angle and height reference as the measurement of the overall size of the fuel rod bundle 8 when collecting images for calibration, ensuring the consistency and reliability of the measurement data.

[0051] The element measurement calibration plate 605 is flush with the center line of the top fuel element 801 of the fuel rod bundle 8, so that the camera has an accurate reference height when measuring the dimensions of a single fuel element 801, and the position and size information of the element can be accurately obtained. Through cooperation, the size of the fuel rod bundle 8 and its elements can be comprehensively and accurately measured, thereby providing a solid guarantee for subsequent accurate measurement.

[0052] As shown in Figure 15 The second aspect of the present application provides a method for underwater size measurement of a heavy water reactor fuel rod bundle, which uses the underwater size measurement system of any one of the above embodiments, and includes the following steps: S202: fixing the fuel rod bundle to the underwater rotating station; S204: driving the first underwater measurement camera to move to the calibration plate area for camera calibration to obtain the pixel conversion coefficient; S206: rotating the fuel rod bundle to a first angle, driving the first underwater measurement camera to move along the axial direction of the fuel rod bundle, and segmenting to collect the overall image of the rod bundle; S208: based on the segmented images, performing splicing and edge extraction, and calculating the length and curvature of the fuel rod bundle at the first angle; S210: rotating the fuel rod bundle to a plurality of different angles, repeating the above image collection and calculation steps, and completing multi-angle size measurement; S212: driving the first underwater measurement camera to move to the calibration plate area for re-calibration of the calibration plate; S214: for each fuel element of the outer circle of the fuel rod bundle, rotating the rod bundle and driving the first underwater measurement camera to move along the axial direction of the element, segmenting to collect the image of a single fuel element, and calculating the length and spacing of each fuel element; S216: reflecting the first end plate image of the fuel rod bundle to the first underwater measurement camera through the first mirror assembly, and performing image collection and diameter measurement; S218: reflecting the second end plate image of the fuel rod bundle to the second underwater measurement camera through the second mirror assembly, and performing image collection and diameter measurement.

[0053] The method for underwater size measurement of a heavy water reactor fuel rod bundle provided by the present application can fix the fuel rod bundle to the underwater rotating station, and drive the first underwater measurement camera to perform multi-step operations, first calibrate to obtain the pixel conversion coefficient, then segment to collect the overall image of the rod bundle and splice to extract the edge, so as to accurately calculate the length and curvature of the fuel rod bundle at the first angle. Repeated measurement at a plurality of different angles can comprehensively grasp the size information of the rod bundle, reduce measurement error, and improve the reliability of the results. Among them, any one fuel element in the fuel rod bundle is marked as a first fuel element, the fuel rod bundle is rotated, and when the first fuel element reaches the position directly above, the angle at which the fuel rod bundle is located is the first angle.

[0054] For each fuel element outside the outer circle of the fuel rod bundle, the rod bundle is rotated in turn and the camera is driven to collect single element image in segments, which can accurately calculate the length and spacing of each fuel element, and meet the fine measurement demand of individual fuel element size.

[0055] The first mirror assembly and the second mirror assembly are used to reflect the images of the two end plates of the fuel rod bundle to the corresponding cameras for collection and diameter measurement, without the need for the cameras to directly face the end plates, which optimizes the camera layout, saves underwater space, and ensures the accuracy and stability of the measurement.

[0056] The method provided by the application first calibrates the camera to ensure the accuracy of the measurement reference, and then gradually carries out various size measurement work. The measurement accuracy is further ensured by recalibrating as needed at different measurement stages. The entire measurement method adapts to the complex underwater environment and can provide comprehensive, accurate and reliable size data support for quality detection, safety evaluation and the like of the heavy water reactor fuel rod bundle.

[0057] In some embodiments provided by the application, the first underwater measurement camera is driven to move above the rod bundle measurement calibration plate for camera calibration to obtain a pixel conversion coefficient, including the following steps: driving the first underwater measurement camera to move above the rod bundle measurement calibration plate; adjusting the height of the first underwater measurement camera to make its field of view completely cover the rod bundle measurement calibration plate; collecting an image of the rod bundle measurement calibration plate, correcting the image, and calculating a pixel conversion coefficient to complete the rod bundle measurement calibration.

[0058] In this embodiment, the first underwater measurement camera is precisely moved above the rod bundle measurement calibration plate, which lays a foundation for subsequent accurate calibration, ensures the correct starting position of the calibration operation, and avoids affecting the calibration accuracy due to position deviation.

[0059] Adjusting the height of the camera to make the field of view completely cover the calibration plate fully considers the differences between different measurement scenarios and camera performance. By flexibly adjusting the height, various actual situations can be adapted to, and it is ensured that all feature information on the calibration plate can be completely collected by the camera, so that the calibration data is more comprehensive and representative.

[0060] After collecting the image of the calibration plate, the correction processing can effectively eliminate the interference factors such as distortion and noise in the image, improve the image quality, and further improve the accuracy of the calibration result. Finally, the pixel conversion coefficient is calculated to complete the rod bundle measurement calibration. This coefficient can accurately convert the pixel size in the image into the actual physical size, provides a reliable conversion basis for subsequent accurate measurement of the length, curvature and other size parameters of the fuel rod bundle, helps to improve the measurement accuracy and reliability of the entire underwater size measurement system, and ensures that the measurement result can truly reflect the actual situation of the fuel rod bundle.

[0061] In some embodiments provided in the present application, driving the first underwater measurement camera to move to the region of the calibration plate to re-calibrate the calibration plate comprises the following steps: driving the first underwater measurement camera to move above the element measurement calibration plate; adjusting the height of the first underwater measurement camera to make the field of view of the first underwater measurement camera completely cover the element measurement calibration plate; collecting the image of the element measurement calibration plate, performing image correction processing, and calculating to obtain a pixel conversion coefficient, and completing the calibration for fuel element measurement.

[0062] In this embodiment, the first underwater measurement camera is accurately moved above the element measurement calibration plate, providing an accurate starting position for subsequent operations, ensuring that the calibration process starts from the correct reference point, effectively avoiding the problem of inaccurate calibration data due to position deviation, and laying a good foundation for accurate measurement of the size of the fuel element.

[0063] Secondly, it is flexible to adjust to various scenarios. The height of the camera is adjusted to make the field of view completely cover the element measurement calibration plate, which fully considers the complexity and diversity of the actual measurement environment. It can be flexibly adjusted according to different situations to ensure that all key features on the calibration plate can be clearly captured by the camera, making the calibration data more comprehensive and representative, and enhancing the reliability of the calibration results.

[0064] Finally, the correction processing improves the calibration accuracy. After collecting the image, the correction processing can eliminate the interference factors such as distortion and noise in the image, and improve the image quality. On this basis, the pixel conversion coefficient obtained is more accurate, which can accurately convert the image pixel size to the actual physical size, and then improve the accuracy of the length and spacing of the fuel element, and ensure that the measurement result truly reflects the actual state of the fuel element.

[0065] In some embodiments provided in the present application, the first end plate image of the fuel rod bundle is reflected to the first underwater measurement camera through the first mirror assembly for image acquisition and diameter measurement, comprising the following steps: starting the rotating positioning mechanism, clamping and positioning the fuel rod bundle, and then releasing the two end positionings; starting the three-dimensional movement mechanism, moving the first underwater measurement camera to the position directly above the end plate mirror, so that the picture of the first underwater measurement camera covers the entire first end plate of the fuel rod bundle; starting the software system of the first underwater measurement camera to complete the image acquisition and edge extraction of the first end plate of the fuel rod bundle; operating the software system of the first underwater measurement camera to complete the appearance inspection and diameter measurement of the first end plate of the fuel rod bundle.

[0066] In this embodiment, the rotating positioning mechanism is started and clamped and positioned, which can effectively fix the fuel rod bundle to prevent displacement due to water flow impact or self-shaking during the measurement process, ensuring the stability of the measurement. Releasing the two end positionings provides convenience for subsequent possible fine adjustment operations, making the measurement process more flexible.

[0067] The three-dimensional moving mechanism is started to precisely move the first underwater measuring camera to the right above the end plate mirror, and to ensure that the camera picture covers the entire first end plate. This operation makes full use of the space, and through precise positioning and movement control, the camera can obtain the end plate image at the best angle and range, avoiding the image information missing caused by incomplete shooting range or poor angle, and providing a high-quality image basis for accurate measurement.

[0068] The first underwater measuring camera software system is started to complete image acquisition and edge extraction, which can quickly and accurately obtain the contour information of the end plate, providing key data for subsequent appearance inspection and diameter measurement. Operating the software system for appearance inspection can timely find defects, damages and other problems on the surface of the end plate, ensuring the quality and safety of the fuel rod bundle. The diameter measurement function can accurately obtain the size parameters of the end plate, providing important data support for the assembly, operation and other aspects of the fuel rod bundle, and helping to improve the operation stability and safety of the entire heavy water reactor system.

[0069] In some embodiments provided in the application, the second end plate image of the fuel rod bundle is reflected to the second underwater measuring camera through the second mirror assembly for image acquisition and diameter measurement, including the following steps: driving the second underwater measuring camera to move horizontally so that its field of view covers the second end plate of the fuel rod bundle; acquiring the reflected image of the second end plate and performing edge extraction processing; based on the extracted edge features, completing the appearance inspection and diameter measurement of the second end plate.

[0070] In this embodiment, in terms of camera positioning, the second underwater measuring camera is driven to move horizontally so that its field of view covers the second end plate. This horizontal movement is simple to operate and accurate in positioning. By accurately controlling the movement distance and direction, the camera can be quickly adjusted to the appropriate position, ensuring that the end plate is completely within the field of view, and avoiding the missing of image information caused by inaccurate positioning, thereby laying a foundation for subsequent accurate measurement.

[0071] In the image acquisition and processing link, the reflected image of the second end plate is acquired and edge extraction processing is performed. The use of reflected imaging ingeniously solves the problem that the camera cannot directly shoot the end plate, saving underwater space and equipment layout difficulty. The edge extraction technology can accurately identify the contour boundary of the end plate, effectively remove noise and interference information in the image, and obtain clear and accurate edge features, greatly improving the image quality.

[0072] In the measurement application, based on the extracted edge features, the appearance inspection and diameter measurement are completed, which can quickly find defects such as scratches, cracks and deformation on the surface of the end plate, ensuring the quality and safety of the fuel rod bundle. At the same time, the accurate edge data provides a reliable basis for diameter measurement, which can accurately calculate the diameter size of the end plate, providing important parameters for the assembly, operation monitoring and other aspects of the fuel rod bundle, and helping to improve the stability and reliability of the entire heavy water reactor system.

[0073] As Figures 1 to 15 shown, in specific embodiments, the present application provides a heavy water reactor fuel bundle underwater size measurement system and measurement method, taking heavy water reactor fuel bundle 8 as the inspection object, measuring the length of the fuel bundle 8, the curvature of the fuel bundle 8, the length of the fuel element 801, the spacing between the fuel elements 801, and the diameter of the end plate. The fuel bundle 8 is composed of fuel elements 801, support pads 802, and end plates. The support pads 802 are welded to the surfaces of the 18 fuel elements 801 on the outer circle of the fuel bundle 8, and the fuel elements 801 are connected and fixed to the end plates on both sides by end resistance welding. The heavy water reactor fuel bundle underwater size measurement system includes an underwater inspection platform 1, a mounting support 2, a first underwater measurement camera 3, a camera motion module 4, a second underwater measurement camera 5, a camera measurement calibration platform 6, a first mirror assembly 7, a second mirror assembly, and a fuel bundle 8.

[0074] The underwater inspection platform 1 includes a three-dimensional movement mechanism 101, a rotary positioning mechanism 102, and a support platform 103. The three-dimensional movement mechanism 101 and the rotary positioning mechanism 102 are installed on the plane of the support platform 103 by fastening screws, respectively. The three-dimensional movement mechanism 101 provides X / Y / Z three-direction walking and positioning for the first underwater measurement camera 3, and the rotary positioning mechanism 102 provides rotation and angle positioning for the fuel bundle 8. The two mechanisms are independent and do not interfere with each other.

[0075] The mounting support 2 is installed on the three-dimensional movement mechanism 101 by fastening screws, and the first underwater measurement camera 3 is vertically connected to the mounting support 2 by a flange and is fixed by screws. The three-dimensional movement mechanism 101 can drive the first underwater measurement camera 3 to walk and position in X / Y / Z three directions, covering the range of the camera measurement calibration platform 6 and the fuel bundle 8.

[0076] The camera motion module 4 includes a connecting base plate 401, a module guide rail 402, a module sliding block 403, a motion support plate 404, an underwater motor 405, a shaft coupling 406, a lead screw 407, a lead screw support 408, a camera support 409, and an end plate mirror 410. The connecting base plate 401 is installed on the support platform 103 through the waist-shaped holes on both sides and using fastening screws, the two module guide rails 402 are symmetrically installed on both sides of the connecting base plate 401 through fastening screws, and the two module sliding blocks 403 slide in the two module guide rails 402 respectively. One end of the lead screw 407 is connected with the underwater motor 405 through the shaft coupling 406, and the other end is supported by the lead screw support 408. The top surface of the lead screw nut on the lead screw 407 is connected with the bottom plate of the camera support 409 through screws, and the bottom plate of the camera support 409 is connected with the module sliding blocks 403 through screws on both sides. The end plate mirror 410 is embedded in the camera support 409 at an angle of 45 degrees. The second underwater measuring camera 5 is vertically connected with the camera support 409 through a flange and is fixed by screws. When the underwater motor 405 rotates, it can drive the second underwater measuring camera 5 to move and position horizontally. The end plate mirror 410 can reflect the image of the second end plate 803 of the fuel rod bundle 8 into the second underwater measuring camera 5.

[0077] The camera measurement calibration platform 6 includes an installation leg 601, a rod bundle measurement calibration plate 602, a pressing plate 603, a support seat 604, an element measurement calibration plate 605, and a pressing strip 606. The installation leg 601 is connected with the support platform 103 through the waist-shaped hole at the bottom and is fixed by screws. The rod bundle measurement calibration plate 602 is placed on the installation leg 601 and is tightly fixed by the pressing plates 603 on both sides. The upper surface of the rod bundle measurement calibration plate 602 is a black and white square pattern, and the height of the upper surface of the rod bundle measurement calibration plate 602 is flush with the center line of the fuel rod bundle 8. When the first underwater measuring camera 3 measures the length and curvature of the fuel rod bundle 8, the rod bundle measurement calibration plate 602 is used to calibrate the first underwater measuring camera 3, calculate the pixel conversion coefficient, and perform image correction. The support seat 604 is installed on one side of the pressing plate 603 of the rod bundle measurement calibration plate 602 through screws. The element measurement calibration plate 605 is placed on the support seat 604 and is tightly fixed by the pressing strips 606 on both sides. The upper surface of the element measurement calibration plate 605 is a black and white square pattern, and the height of the upper surface of the element measurement calibration plate 605 is flush with the center line of the fuel elements 801 at the top of the fuel rod bundle 8. When the first underwater measuring camera 3 measures the length and spacing of the fuel elements 801, the element measurement calibration plate 605 is used to calibrate the first underwater measuring camera 3, calculate the pixel conversion coefficient, and perform image correction.

[0078] The first mirror assembly comprises a mirror bracket 701, an end plate mirror 702, and a mirror pressing strip 703. The mirror bracket 701 is connected to the support platform 103 through a bottom waist hole and is fixed by screw mounting. The end plate mirror 702 is embedded in the mirror bracket 701 at an angle of 45 degrees and is tightly fixed by the mirror pressing strips 703 on both sides. The end plate mirror 702 can reflect the image of the first end plate of the fuel rod bundle 8 into the first underwater measurement camera 3.

[0079] The fuel rod bundle underwater size measurement method comprises two parts: a rod bundle measurement process and an end plate measurement process.

[0080] As shown in Figure 13 , the rod bundle measurement process comprises the following steps: (1) Place the fuel rod bundle on the rotating positioning mechanism inspection station; (2) Start the rotating positioning mechanism to clamp and position the fuel rod bundle; (3) Start the three-dimensional movement mechanism, adjust the X / Y value, so that the first underwater measurement camera reaches the position directly above the rod bundle measurement calibration plate, and then adjust the Z value, so that the image of the first underwater measurement camera covers the entire rod bundle measurement calibration plate; (4) Start the first underwater measurement camera software system, collect the image of the rod bundle measurement calibration plate and correct the image, and at the same time calculate the pixel conversion coefficient, complete the rod bundle measurement calibration; (5) Start the rotating positioning mechanism to rotate the fuel rod bundle to the 0-degree position; (6) Start the three-dimensional movement mechanism to move the first underwater measurement camera to the position where the center line of the fuel rod bundle is located in the center of the camera image, and then complete the segmented photographing and collection of the fuel rod bundle along the axial direction of the fuel rod bundle; (7) Start the first underwater measurement camera software system to complete the image splicing and edge extraction of the segmented fuel rod bundle; (8) Operate the first underwater measurement camera software system to complete the length measurement of the fuel rod bundle at this angle; (9) Operate the first underwater measurement camera software system to complete the curvature measurement of the fuel rod bundle at this angle; (10) Repeat steps (5) to (9), rotate the fuel rod bundle by 90 degrees each time, and complete the length and curvature measurement of the fuel rod bundle at four angles; (11) Start the three-dimensional movement mechanism, adjust the X / Y value, so that the first underwater measurement camera reaches the position directly above the element measurement calibration plate, and then adjust the Z value, so that the image of the first underwater measurement camera covers the entire element measurement calibration plate; (12) Start the first underwater measurement camera software system to collect the image of the element measurement calibration plate and correct the image, and at the same time calculate the pixel conversion coefficient, complete the element measurement calibration; (13) Start the three-dimensional moving mechanism, move the first underwater measuring camera to the center line of the fuel element in the middle of the camera screen, and then complete the whole segmented photographing and collection of the fuel element along the axial direction of the fuel element; (14) Start the first underwater measuring camera software system to complete the image splicing and edge extraction of the fuel element segments; (15) Operate the first underwater measuring camera software system to complete the length measurement of the fuel element; (16) Operate the first underwater measuring camera software system to complete the fuel element spacing measurement; (17) Start the rotating positioning mechanism to rotate the fuel rod bundle by 20 degrees; (18) Repeat steps (12) to (17), and the fuel rod bundle is rotated by 20 degrees each time to complete the length and spacing measurement of the 18 fuel elements in the outer circle of the fuel rod bundle; (19) Start the rotating positioning mechanism to loosen the clamping and limit, and then grasp the fuel rod bundle away from the rotating positioning mechanism inspection station.

[0081] As shown in Figure 14 , the end plate measurement process includes the following steps: (1) Place the fuel rod bundle on the rotating positioning mechanism inspection station; (2) Start the rotating positioning mechanism to clamp and limit the fuel rod bundle, and then loosen the two end limits; (3) Start the three-dimensional moving mechanism to move the first underwater measuring camera to the top of the end plate mirror, so that the first underwater measuring camera screen covers the entire first end plate of the fuel rod bundle; (4) Start the first underwater measuring camera software system to complete the image collection and edge extraction of the first end plate of the fuel rod bundle; (5) Operate the first underwater measuring camera software system to complete the appearance inspection and diameter measurement of the first end plate of the fuel rod bundle; (6) Start the underwater motor of the camera motion module to move the second underwater measuring camera horizontally to cover the entire second end plate of the fuel rod bundle; (7) Start the second underwater measuring camera software system to complete the image collection and edge extraction of the second end plate of the fuel rod bundle; (8) Operate the second underwater measuring camera software system to complete the appearance inspection and diameter measurement of the second end plate of the fuel rod bundle; (9) Grasp the fuel rod bundle away from the rotating positioning mechanism inspection station.

[0082] Specific embodiment (one): fuel rod bundle measurement: Step one: Place the fuel rod bundle on the rotating positioning mechanism inspection station; Step two: Start the rotating positioning mechanism to clamp and limit the fuel rod bundle; Step three: start the three-dimensional moving mechanism, adjust the X / Y value, so that the first underwater measuring camera reaches the position directly above the rod bundle measurement calibration board, and then adjust the Z value, so that the first underwater measuring camera picture covers the entire rod bundle measurement calibration board; Step four: start the first underwater measuring camera software system, collect the rod bundle measurement calibration board image and correct the image, and calculate the pixel conversion coefficient, complete the rod bundle measurement calibration; Step five: start the rotating positioning mechanism, rotate the fuel rod bundle to 0 degree position; Step six: start the three-dimensional moving mechanism, move the first underwater measuring camera to the fuel rod bundle center line in the camera picture, and then complete the whole segmented photographing collection of the fuel rod bundle along the axial direction of the fuel rod bundle; Step seven: start the first underwater measuring camera software system, complete the fuel rod bundle segmented image stitching and edge extraction; Step eight: operate the first underwater measuring camera software system, complete the length measurement of the fuel rod bundle at this angle; Step nine: operate the first underwater measuring camera software system, complete the curvature measurement of the fuel rod bundle at this angle; Step ten: repeat steps five to nine, rotate the fuel rod bundle by 90 degrees each time, complete the length and curvature measurement of the fuel rod bundle at four angles; Step eleven: start the three-dimensional moving mechanism, adjust the X / Y value, so that the first underwater measuring camera reaches the position directly above the component measurement calibration board, and then adjust the Z value, so that the first underwater measuring camera picture covers the entire component measurement calibration board; Step twelve: start the first underwater measuring camera software system, collect the component measurement calibration board image and correct the image, and calculate the pixel conversion coefficient, complete the component measurement calibration; Step thirteen: start the three-dimensional moving mechanism, move the first underwater measuring camera to the fuel component center line in the camera picture, and then complete the whole segmented photographing collection of the fuel component along the axial direction of the fuel component; Step fourteen: start the first underwater measuring camera software system, complete the fuel component segmented image stitching and edge extraction; Step fifteen: operate the first underwater measuring camera software system, complete the fuel component length measurement; Step sixteen: operate the first underwater measuring camera software system, complete the fuel component spacing measurement; Step seventeen: start the rotating positioning mechanism, rotate the fuel rod bundle by 20 degrees; Step eighteen: repeat steps twelve to seventeen, rotate the fuel rod bundle by 20 degrees each time, complete the length and spacing measurement of the 18 fuel components in the outer circle of the fuel rod bundle; Step nineteen: start the rotary positioning mechanism, loosen the clamping limit, and pick up the fuel rod bundle from the rotary positioning mechanism inspection station.

[0083] Specific embodiment (two): rod bundle end plate measurement Step one: place the fuel rod bundle gripper on the rotary positioning mechanism inspection station; Step two: start the rotary positioning mechanism, clamp the fuel rod bundle, and loosen the two end limits; Step three: start the three-dimensional movement mechanism, move the first underwater measurement camera to the top of the end plate mirror, so that the first underwater measurement camera covers the entire fuel rod bundle first end plate; Step four: start the first underwater measurement camera software system to complete the fuel rod bundle first end plate image acquisition and edge extraction; Step five: operate the first underwater measurement camera software system to complete the fuel rod bundle first end plate appearance inspection and diameter measurement; Step six: start the underwater motor of the camera movement module to move the second underwater measurement camera horizontally to cover the entire fuel rod bundle second end plate; Step seven: start the second underwater measurement camera software system to complete the fuel rod bundle second end plate image acquisition and edge extraction; Step eight: operate the second underwater measurement camera software system to complete the fuel rod bundle second end plate appearance inspection and diameter measurement; Step nine: pick up the fuel rod bundle from the rotary positioning mechanism inspection station.

[0084] In the present application, the term "a plurality of" refers to two or more, unless otherwise explicitly limited. The terms "mounting", "connected", "connection", "fixed" and the like should be interpreted broadly, for example, "connection" can be fixed connection, or detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0085] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "specific embodiment" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The above descriptions are only the preferred embodiments of the present application, and are not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A heavy water reactor fuel bundle underwater dimensional measurement system, the fuel bundle comprising a plurality of fuel elements and first and second end plates disposed at opposite ends of the fuel elements, characterized by, The heavy water reactor fuel bundle underwater size measurement system comprises: a support platform; a rotary positioning mechanism arranged on the support platform and used for clamping and driving the fuel bundle to rotate; a three-dimensional movement mechanism arranged on the support platform; a first underwater measurement camera arranged on the three-dimensional movement mechanism and driven by the three-dimensional movement mechanism to move in a three-dimensional space, and used for collecting overall images of the fuel bundle and images of single fuel element; a camera measurement calibration platform arranged on the support platform and comprising a bundle measurement calibration plate and an element measurement calibration plate; a first mirror assembly arranged on the support platform and used for reflecting images of the first end plate to the first underwater measurement camera; a camera movement module arranged on the support platform and comprising two module guide rails and a camera support capable of sliding along the module guide rails; a second underwater measurement camera arranged on the camera support and used for collecting images of the second end plate; a second mirror assembly arranged on the camera support and used for reflecting images of the second end plate to the second underwater measurement camera.

2. The heavy water reactor fuel bundle underwater dimensional measurement system of claim 1, wherein, The camera movement module further comprises a connecting bottom plate and a lead screw transmission mechanism. The connecting bottom plate is arranged on the support platform, and the two module guide rails are arranged side by side on two sides of the connecting bottom plate. The lead screw transmission mechanism comprises a lead screw, a lead screw support, an underwater motor and a lead screw nut. The lead screw support is arranged on the connecting bottom plate. One end of the lead screw is connected to the underwater motor through a shaft coupling. The other end of the lead screw is supported by the lead screw support. The lead screw is located between the two module guide rails. The lead screw nut is connected to the camera support. The camera support is slidingly matched with the module guide rails through a module sliding block.

3. The heavy water reactor fuel bundle underwater dimensional measurement system of claim 1, wherein, The first mirror assembly comprises: a mirror support arranged on the support platform; an end plate mirror embedded in the mirror support at a preset angle.

4. The heavy water reactor fuel bundle underwater dimensional measurement system of claim 1, wherein, The camera measurement calibration platform further comprises: a mounting leg arranged on the support platform. The bundle measurement calibration plate is arranged on the mounting leg and fixed by a pressing plate. a support seat arranged on the pressing plate. The element measurement calibration plate is arranged on the support seat and fixed by a pressing strip.

5. The heavy water reactor fuel bundle underwater size measurement system according to claim 1, wherein a black and white grid pattern is arranged on the upper surface of the bundle measurement calibration plate. The upper surface of the bundle measurement calibration plate is flush with the center line of the fuel bundle. a black and white grid pattern is arranged on the upper surface of the element measurement calibration plate. The upper surface of the element measurement calibration plate is flush with the center line of the top fuel element of the fuel bundle.

6. A method for measuring the underwater dimensions of a heavy water reactor fuel bundle, characterized in that, The heavy water reactor fuel bundle underwater size measurement system according to any one of claims 1 to 5 comprises the following steps: fixing the fuel bundle on an underwater rotating station; driving the first underwater measurement camera to move to the calibration plate area for camera calibration and obtaining pixel conversion coefficients; rotating the fuel bundle to a first angle and driving the first underwater measurement camera to move along the fuel bundle axis to collect segmented overall images of the fuel bundle; Based on the segmented image, the image is spliced and the edge is extracted, and the length and the bending degree of the fuel rod bundle at the first angle are calculated; The fuel rod bundle is rotated to different angles, and the above image acquisition and calculation steps are repeated to complete the multi-angle size measurement; The first underwater measurement camera is driven to move to the calibration plate area for re-calibration of the calibration plate; For each fuel element of the outer circle of the fuel rod bundle, the rod bundle is rotated in turn and the first underwater measurement camera is driven to move along the element axial direction to segmentally acquire single fuel element images, and the length and spacing of each fuel element are calculated; The first end plate image of the fuel rod bundle is reflected to the first underwater measurement camera through the first mirror assembly for image acquisition and diameter measurement; The second end plate image of the fuel rod bundle is reflected to the second underwater measurement camera through the second mirror assembly for image acquisition and diameter measurement.

7. The method of claim 6, wherein, The first underwater measurement camera is driven to move to the calibration plate area for camera calibration to obtain pixel conversion coefficients, comprising: The first underwater measurement camera is driven to move above the rod bundle measurement calibration plate; The height of the first underwater measurement camera is adjusted to make its field of view completely cover the rod bundle measurement calibration plate; The image of the rod bundle measurement calibration plate is acquired, the image is corrected, and the pixel conversion coefficient is calculated to complete the rod bundle measurement calibration.

8. The method of claim 6, wherein the method further comprises: The first underwater measurement camera is driven to move to the calibration plate area for re-calibration of the calibration plate, comprising: The first underwater measurement camera is driven to move above the element measurement calibration plate; The height of the first underwater measurement camera is adjusted to make its field of view completely cover the element measurement calibration plate; The image of the element measurement calibration plate is acquired, the image is corrected, and the pixel conversion coefficient is calculated to complete the calibration for fuel element measurement.

9. The method of claim 6, wherein, The first end plate image of the fuel rod bundle is reflected to the first underwater measurement camera through the first mirror assembly for image acquisition and diameter measurement, comprising the following steps: Start the rotary positioning mechanism, clamp and position the fuel rod bundle, and then release the two end positionings; Start the three-dimensional movement mechanism, move the first underwater measurement camera to the exact position above the end plate mirror, and make the first underwater measurement camera image cover the entire first end plate of the fuel rod bundle; Start the first underwater measurement camera software system to complete the image acquisition and edge extraction of the first end plate of the fuel rod bundle; Operate the first underwater measurement camera software system to complete the appearance inspection and diameter measurement of the first end plate of the fuel rod bundle.

10. The method of claim 6, wherein, The second end plate image of the fuel rod bundle is reflected to the second underwater measurement camera through the second mirror assembly for image acquisition and diameter measurement, comprising the following steps: Drive the second underwater measurement camera to move horizontally to make its field of view cover the second end plate of the fuel rod bundle; Acquire the reflected image of the second end plate and perform edge extraction processing; Based on the extracted edge features, the appearance inspection and diameter measurement of the second end plate are completed.

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