Nuclear reactor pressure vessel top cover deflation pipe inspection device

Abstract

The invention relates to the technical field of nuclear power auxiliary inspection devices, in particular to a nuclear reactor pressure vessel top cover deflation pipe inspection device which comprises a carrying moving vehicle provided with Mecanum wheels, and further comprises an inspection part, an inspection part and a control part, and the inspection part comprises a double-shaft mechanical arm installed on the carrying moving vehicle through a plane moving assembly; a plurality of sections of lifting pipes are mounted on the double-shaft mechanical arm through a power source in a lifting manner; an inspection unit is detachably mounted at the outer end of the raising pipe; according to the device, automatic inspection can be achieved, the inspection position and angle can be adjusted, positioning inspection can be rapidly achieved, the inspection efficiency and accuracy are greatly improved, manual intervention is reduced, and the risk that the human body is irradiated by radioactive rays is reduced; according to the device, modularization is achieved, the number of parts of the whole equipment is reduced, the weight of the parts of the whole equipment is reduced, the portability and operation convenience of the equipment are greatly improved, the transportation and assembly difficulty is lowered, and the operation efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear power auxiliary inspection devices, specifically to an inspection device for the vent pipe of the top cover of a nuclear reactor pressure vessel. Background Technology

[0002] The top cover of a nuclear reactor pressure vessel is a critical pressure-bearing boundary that encloses the reactor core. Its main functions are to seal the reactor coolant, maintain stable internal pressure, and prevent the leakage of radioactive materials. As an important component of the top cover, the vent pipe plays a crucial role in releasing gases accumulated inside the top cover (such as hydrogen and steam generated during operation), directly affecting the pressure control capability and sealing integrity of the top cover.

[0003] From a safety perspective, failure of the vent pipe (such as blockage, cracking, or corrosion) can lead to the following risks: If the vent pipe is blocked, the pressure inside the top cover cannot be released normally, which may exceed the design limit and cause leakage at the top cover sealing surface. At the same time, the blockage of the vent pipe will affect the gas replacement efficiency during top cover maintenance, prolong downtime, and increase operation and maintenance costs. If the crack in the vent pipe penetrates the wall thickness, radioactive materials in the reactor coolant will leak through the vent pipe, threatening the plant environment and personnel safety. Therefore, pre-service inspection and in-service inspection of the vent pipe are key links that are mandatory requirements of nuclear power regulations. Their purpose is to detect defects in the vent pipe in a timely manner and ensure its functional integrity.

[0004] Currently, most vent pipe inspections rely on visual inspection or manual handheld endoscope inspection. However, these methods have significant drawbacks: high risk of personnel exposure, insufficient accuracy and efficiency, and low degree of automation, which cannot meet the requirements of modern nuclear power for inspection accuracy and safety. Therefore, in order to solve the above-mentioned defects and meet the inspection requirements, we propose a nuclear reactor pressure vessel top cover vent pipe inspection device. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings mentioned in the background section and to provide an inspection device for the vent pipe of the top cover of a nuclear reactor pressure vessel.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A device for inspecting the vent pipe of a nuclear reactor pressure vessel top cover includes a mobile transport vehicle equipped with Mecanum wheels, and further includes: The inspection unit includes a dual-axis robotic arm mounted on the transport vehicle via a planar movement assembly, and the dual-axis robotic arm is equipped with multiple lifting sections via a power source. The outer end of the lifting pipe is detachably equipped with an inspection unit for internal inspection, which is inserted into the vent pipe of the top cover.

[0007] Preferably, the planar moving component includes an X-axis guide rail mounted on the transport vehicle along the horizontal X-axis direction, and an X-axis moving plate is slidably mounted on the X-axis guide rail; The X-axis movable plate is equipped with a Y-axis guide rail along the Y-axis direction of the horizontal plane, and the Y-axis movable plate is slidably mounted on the Y-axis guide rail.

[0008] Preferably, the dual-axis robotic arm includes a rotating arm rotatably mounted on the Y-axis moving plate along the horizontal plane, and a pitching arm is rotatably mounted on the rotating arm; The pitch arm rotation surface is perpendicular to the Y-axis moving plate surface.

[0009] Preferably, a mounting frame is detachably mounted on the pitch arm, and a lifting cylinder as a power source is detachably mounted inside the mounting frame.

[0010] Preferably, the multiple sections of the lifting tube are detachably connected by an internally threaded sleeve.

[0011] Preferably, the inspection unit is either an endoscope probe or an ultrasonic flaw detector probe that can be inserted into the vent pipe of the top cover.

[0012] Preferably, the rotating arm is located at the center of the Y-axis moving plate, and a centering camera is coaxially mounted at the top of the rotating arm. The centering camera is used to align and position the inspection unit with the vent pipe of the top cover.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The nuclear reactor pressure vessel top cover vent pipe inspection device can realize automated inspection, adjust the inspection position and angle, and quickly realize positioning inspection, which greatly improves the efficiency and accuracy of inspection, reduces manual intervention, and reduces the risk of human exposure to radioactive rays. 2. This device is modular, which simplifies the number and weight of the overall equipment, greatly improves the portability and ease of operation, reduces the difficulty of transportation and assembly, and improves operating efficiency. Attached Figure Description

[0014] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is one of the schematic diagrams of the overall structure of the present invention; Figure 2 This is the second schematic diagram of the overall structure of the present invention; Figure 3 This is the third schematic diagram of the overall structure of the present invention; Figure 4This is a schematic diagram of the centering process of the centering camera in this invention.

[0015] The meanings of the labels in the diagram are as follows: 1. Transport vehicle; 11. Mecanum wheel; 2. X-axis moving plate; 3. Y-axis moving plate; 4. X-axis guide rail; 5. Y-axis guide rail; 6. Dual-axis robotic arm; 61. Rotary arm; 62. Pitch arm; 7. Mounting frame; 8. Lifting cylinder; 9. Lifting tube; 10. Endoscopic probe. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-4 The present invention will describe the above technical solution in detail through the following embodiments: The nuclear reactor pressure vessel top cover vent pipe inspection device of this embodiment includes a transport vehicle 1 equipped with Mecanum wheels 11. The Mecanum wheels 11 can move flexibly to achieve stability control. Specifically, in order to achieve the positioning and alignment function, this application is designed with an inspection unit.

[0018] The inspection unit includes a dual-axis robotic arm 6 mounted on a transport vehicle 1 via a planar motion assembly. The planar motion assembly includes an X-axis guide rail 4 mounted on the transport vehicle 1 along the horizontal X-axis direction. An X-axis moving plate 2 is slidably mounted on the X-axis guide rail 4 via a drive motor. Similarly, a Y-axis guide rail 5 along the horizontal Y-axis direction is mounted on the X-axis moving plate 2. A Y-axis moving plate 3 is slidably mounted on the Y-axis guide rail 5 via a drive motor. A rotating arm 61 of the dual-axis robotic arm 6 is rotatably mounted on the Y-axis moving plate 3. The rotating arm 61 can rotate 360° in the horizontal plane, facilitating observation of the entire inside of the tube. A pitch arm 62 with its rotation surface perpendicular to the surface of the Y-axis moving plate 3 is rotatably mounted on the rotating arm 61. The pitch arm 62 can be placed horizontally for easy access to the device and is used to realize the pitch movement of the robotic arm, thereby realizing the lifting movement of the video inspection device. In this embodiment, the planar motion assembly is moved along the horizontal X-axis and horizontal Y-axis via a drive motor, and the total stroke is set to 200 mm per axis.

[0019] In this embodiment, a mounting bracket 7 is detachably installed on the pitch arm 62. A lifting cylinder 8 is detachably installed inside the mounting bracket 7 as a power source. A lifting tube 9 is coaxially installed on the output shaft of the lifting cylinder 8. In order to meet different inspection height requirements, several lifting tubes 9 can be threadedly installed and removed. With the lifting cylinder 8, the endoscopic probe 10 installed at the top of the lifting tube 9 can be inserted into the vent pipe of the top cover. In other embodiments, the probe can be replaced, such as an ultrasonic flaw detection probe.

[0020] Considering the need for alignment, this embodiment sets the rotating arm 61 at the center of the transport vehicle 1, and a centering camera is coaxially mounted at the top of the rotating arm 61. The centering camera is used to achieve alignment and positioning of the inspection unit and the vent pipe of the top cover. Specifically, the crosshair at the center of the centering camera's image is used as a calibration reference, and the characteristic position of the vent pipe hole on the top cover is identified and matched by the image processing algorithm, thereby achieving precise visual positioning of the device.

[0021] Reference Appendix Figure 4 The power and signal interfaces on the trolley are connected via cable connectors to provide power and control signal paths for the entire device. The mobile trolley 1 and the dual-axis robotic arm 6 are connected via independent power and signal interfaces to enable the trolley to supply power and transmit control commands to the dual-axis robotic arm 6. This part belongs to the existing mature motion control program, so it will not be explained in detail. A PoE network cable is installed for the centering camera to realize the data transmission and power supply of the centering camera.

[0022] The centering camera collects images of the top cover surface in real time during the device's movement and performs image preprocessing. Through a dynamic feature recognition algorithm, it continuously tracks the visual features of the venting pipe hole on the top cover, completes coordinate transformation, and calculates its real-time spatial pose deviation relative to the device. This deviation data is fed back to the control system to generate motion compensation commands, providing real-time visual guidance for the subsequent precise positioning of the venting pipe by the dual-axis robotic arm 6 and the planar movement component.

[0023] The specific positioning method is as follows: the real-time acquired images are first subjected to local adaptive histogram equalization to eliminate the interference of uneven illumination. Then, Gaussian filtering and median filtering are cascaded to suppress image noise. The sub-pixel-level edge features of the vent hole are enhanced by the DBSCAN and K-means++ hybrid clustering algorithm, thus establishing a robust input foundation for the recognition process.

[0024] The system accurately locates the center of the hole based on sub-pixel-level edge detection. By analyzing the contour curvature distribution and radial gradient features, and combining a pre-trained template matching algorithm, it achieves millisecond-level feature recognition. The extracted 2D center coordinates are input into the perspective projection model and mapped to 3D coordinates in the robotic arm's base coordinate system based on the camera's intrinsic and extrinsic calibration data. Based on the principle of minimizing reprojection error, the system calculates the deviation vector between the theoretical coordinates and the actual recognition coordinates in real time, outputting translation error (Δx, Δy) and rotation error (Δθ). This deviation data drives the control system to generate displacement command coordinates (X, Y) for the planar moving component and rotation compensation for the end of the dual-axis robotic arm 6. This drives the planar moving component to its final position (X, Y) and simultaneously drives the dual-axis robotic arm 6 to rotate until the center of the image captured by the endoscope probe 10 is dynamically aligned with the center of the vent hole. Through the above closed-loop adjustment mechanism, the coaxial calibration of the endoscope probe 10 and the center of the target vent hole is finally achieved, establishing a precise spatial reference for the safe insertion of the endoscope probe 10.

[0025] After precise positioning, the endoscope probe 10 at the top is inserted into the vent tube of the top cover. In this embodiment, the lens of the endoscope probe 10 has a built-in LED light source, which provides uniform illumination during the inspection process, ensuring high-definition imaging of the inner wall structure of the vent tube, thereby ensuring the accuracy and efficiency of the internal video inspection. At the same time, the slow extension and retraction operation also ensures the safety of the video inspection device. Through the above structural design and cooperation, the device of the present invention can realize automated and intelligent inspection of the vent tube of the top cover, significantly improving inspection efficiency and reliability.

[0026] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A nuclear reactor pressure vessel head vent tube inspection device comprising a mobile carrier cart (1) fitted with a Mecanum wheel (11), characterized in that: Also include: Inspection unit, comprising a double-axis mechanical arm (6) installed on the carrying mobile vehicle (1) through a plane moving assembly, a plurality of high-lift pipes (9) are installed on the double-axis mechanical arm (6) through a power source lifting; The outer end of the high-lift pipe (9) is detachably installed with an inspection unit for inserting into the top cover gas pipe for internal inspection.

2. The nuclear reactor vessel head vent tube inspection apparatus of claim 1, wherein: The plane moving assembly comprises an X-direction guide rail (4) installed on the carrying mobile vehicle (1) along the horizontal plane X-axis direction, and an X-direction moving plate (2) is slidably installed on the X-direction guide rail (4); The X-direction moving plate (2) is provided with a Y-direction guide rail (5) along the horizontal plane Y-axis direction, and a Y-direction moving plate (3) is slidably installed on the Y-direction guide rail (5).

3. The nuclear reactor vessel head vent tube inspection apparatus of claim 2, wherein: The double-axis mechanical arm (6) comprises a rotating arm (61) installed on the Y-direction moving plate (3) along the horizontal plane, and a pitch arm (62) is rotatably installed on the rotating arm (61); The pitch arm (62) is rotatably installed on the rotating arm (61).

4. The nuclear reactor vessel head vent tube inspection apparatus of claim 3, wherein: The pitch arm (62) is detachably installed with a mounting bracket (7), and a lifting cylinder (8) is detachably installed in the mounting bracket (7) as a power source.

5. The nuclear reactor vessel head vent tube inspection apparatus of claim 1, wherein: The plurality of high-lift pipes (9) are detachably connected through an internal threaded sleeve.

6. The nuclear reactor vessel head vent tube inspection apparatus of claim 1, wherein: The inspection unit adopts any one of an endoscopic probe (10) capable of being inserted into the top cover gas pipe and an ultrasonic flaw detection probe.

7. The nuclear reactor vessel head vent tube inspection apparatus of claim 3, wherein: The rotating arm (61) is arranged at the center position of the Y-direction moving plate (3), and a centering camera is coaxially installed at the top end of the rotating arm (61), which is used for realizing the alignment positioning of the inspection unit and the top cover gas pipe.

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