Reactor pressure vessel inspection equipment and methods

Abstract

This invention discloses a reactor pressure vessel inspection device and method. The reactor pressure vessel inspection device includes a support frame, a lifting mechanism mounted on the support frame, a rotating mechanism mounted on the lower part of the lifting mechanism facing the vessel body, a nozzle scanning arm mounted below the rotating mechanism, and two multi-degree-of-freedom robotic arm probe frames. The lifting mechanism is movable relative to the support frame, driving the rotating mechanism and its nozzle scanning arm and multi-degree-of-freedom robotic arm probe frames to move up and down along the central axis of the vessel body. The rotating mechanism drives the nozzle scanning arm and multi-degree-of-freedom robotic arm probe frames to rotate. This invention uses two multi-degree-of-freedom robotic arm probe frames to cooperate with the nozzle scanning arm to perform inspection work on the reactor pressure vessel. The multi-degree-of-freedom robotic arm probe frames and the nozzle scanning arm can scan synchronously and in parallel, reducing inspection time, improving work efficiency, and greatly reducing the critical path time for nuclear power plant overhauls.

Description

Technical Field

[0001] This invention relates to the field of in-service inspection technology for nuclear power equipment, and in particular to an inspection device and method for reactor pressure vessels. Background Technology

[0002] The most critical component of a nuclear power plant is the reactor pressure vessel, located at the center of the reactor building. It secures, supports, and encloses the reactor core and all internal components. Inside, the nuclear fuel undergoes a chain reaction of fission under neutron irradiation. The reactor pressure vessel is also the only large, non-replaceable component throughout the entire lifespan of the nuclear power plant. During normal operation, it withstands high temperatures, high pressures, and extremely high levels of radioactivity. To ensure the safety of the nuclear reactor pressure vessel, it is necessary to conduct regular non-destructive testing to identify potential structural damage, assess its safety status, and determine whether remedial measures are required.

[0003] The in-service inspection specifications and guidelines for nuclear power plants mandate non-destructive testing (NDT) for welds, bolt holes, weld overlays, and the base metal in the high-flux neutron region of the reactor pressure vessel. They also specify pre-service and in-service inspections of the pressure vessel, to be conducted before commissioning and at regular intervals. The results of these inspections serve as crucial evidence for analyzing and evaluating the pressure vessel's operational status and extending its lifespan. Even after unit shutdown, the reactor pressure vessel retains high levels of radioactivity due to the presence of activation products, making full-range, long-term manual inspection impossible. Therefore, safe and reliable automated inspection equipment is an essential element for reactor pressure vessel inspection. Furthermore, reactor pressure vessel inspection has always been a critical part of nuclear power plant overhauls; inspection efficiency is paramount, directly impacting the overhaul schedule and the unit's power generation efficiency.

[0004] Existing reactor pressure vessel inspection devices fall into several categories. The first type consists of large inspection devices with multiple probe mounts installed in a fixed position on the reactor pressure vessel. However, due to the dispersed nature of the inspected locations, inspections often involve a single ultrasonic probe mount sequentially scanning the reactor pressure vessel's shell butt welds, bottom head butt welds, shell weld overlay, nozzle-to-shell welds, safety end welds, and inner rounded corner areas of the nozzles. The second type utilizes multi-degree-of-freedom general-purpose robotic arms, but these have limited load capacity and require frequent repositioning and probe mount changes to sequentially inspect multiple locations on the reactor pressure vessel, resulting in numerous changes and low inspection efficiency. The third type comprises specialized inspection devices designed for nozzles, flange faces, and shell welds. Each device inspects one type of object, and the number of different types of equipment significantly increases the complexity of on-site installation, transportation, and use. All of these existing inspection devices severely limit the efficiency of reactor pressure vessel inspections and increase the workload and risk of human error for on-site operators. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an improved reactor pressure vessel inspection device and a reactor pressure vessel inspection method.

[0006] The technical solution adopted by the present invention to solve its technical problem is: to provide a reactor pressure vessel inspection device, including a support frame for mounting on the flange surface of the cylinder of the pressure vessel, a lifting mechanism mounted on the support frame and coaxial with the cylinder, a rotating mechanism mounted on the lifting mechanism facing the lower part of the cylinder, a pipe scanning arm mounted below the rotating mechanism, and two multi-degree-of-freedom robotic arm probe frames.

[0007] The lifting mechanism is movable relative to the support frame, driving the rotating mechanism and the tube scanning arm and multi-degree-of-freedom robotic arm probe frame on it to move up and down along the central axis of the cylinder; the rotating mechanism is used to drive the tube scanning arm and multi-degree-of-freedom robotic arm probe frame to rotate around the central axis of the cylinder; the tube scanning arm and the two multi-degree-of-freedom robotic arm probe frames are used to perform synchronous parallel scanning of the cylinder.

[0008] In some embodiments, the support frame includes four support legs for standing upright on the flange surface of the cylinder, and a connecting bracket connected between the four support legs and capable of spanning across the flange surface of the cylinder.

[0009] The four support legs are distributed circumferentially along the flange surface, wherein the two support legs located at diagonal positions are respectively used to cooperate with the guide posts on the flange surface.

[0010] In some embodiments, the lifting mechanism includes a lifting column that is perpendicular to the connecting bracket and passes through the connecting bracket;

[0011] The two ends of the lifting column are located on the upper and lower sides of the connecting bracket, respectively. The rotating mechanism is installed on the lower end of the lifting column located on the lower side of the connecting bracket. The lower end of the lifting column is retractable, which drives the rotating mechanism to move up and down.

[0012] In some embodiments, the rotating mechanism includes a support plate, a hollow cable carrier, a torque motor with an absolute encoder, a connecting cylinder, and a rotating disk.

[0013] The cable carrier and the connecting cylinder are connected to opposite sides of the support plate, and the support plate has a through hole connecting the cable carrier and the connecting cylinder; the end of the cable carrier away from the support plate is fixedly connected to the lifting column; the rotating disk is sleeved on the outer periphery of the connecting cylinder and can rotate relative to the connecting cylinder; the torque motor is set on the support plate, connected to and drives the rotating disk to rotate;

[0014] The rotating disk is provided with a number of spaced mounting holes for mounting the tube scanning arm and the multi-degree-of-freedom robotic arm probe frame under the rotating disk.

[0015] In some embodiments, at least one side of the cable carrier is provided with a cable hole communicating with its internal space.

[0016] The support plate is provided with a connection unit integrating several connectors. The connecting cables of the tube scanning arm and the multi-degree-of-freedom robotic arm probe frame pass through the cable tray and are connected to the connectors of the connection unit.

[0017] In some embodiments, the reactor pressure vessel inspection equipment further includes a cable winding winch mounted on the lifting mechanism. The lifting end of the cable winding winch is provided with a cable rack for suspending cables. External connecting cables are suspended on the cable rack, with one end connected to the connector of the connecting unit and the other end used for external control system connection.

[0018] In some embodiments, the multi-degree-of-freedom robotic arm probe holder includes a six-degree-of-freedom robotic arm and a probe holder;

[0019] The six-degree-of-freedom robotic arm is mounted below the rotating mechanism with its first joint parallel to the central axis of the cylinder and through a first quick-release structure. The probe holder is detachably mounted on the sixth joint of the six-degree-of-freedom robotic arm away from the rotating mechanism through a second quick-release structure.

[0020] In some embodiments, the first quick-release structure includes a positioning post disposed on the first joint of the six-degree-of-freedom robotic arm, a positioning hole adapted to the positioning post and disposed on the rotating mechanism, a positioning pin protruding from the first joint and located on at least one side of the positioning post, a pin hole disposed on the rotating mechanism and located on at least one side of the positioning hole, and a locking member; the positioning post is inserted into the positioning hole from one side and fitted into the positioning hole, while the positioning pin is fitted into the pin hole, and the locking member is inserted into the positioning hole from the other side and fastened to the positioning post.

[0021] In some embodiments, the second quick-assembly structure includes a first connecting seat disposed on the sixth joint of the six-degree-of-freedom robotic arm, a second connecting seat disposed on the probe holder, and a docking assembly;

[0022] The first connecting seat is provided with an axially connected mating hole and a screw hole; the second connecting seat is provided with a mating post on one side that is adapted to the mating hole, and the second connecting seat is also provided with a central channel that extends through the mating post. The mating assembly is inserted into the central channel and can move and rotate axially relative to the central channel; the mating assembly includes an axially connected rotating operating part and a screw.

[0023] When the first connecting seat and the second connecting seat are mated, the mating post is engaged in the mating hole, and the mating assembly rotates with the screw facing the screw hole, so that the screw is engaged in the screw hole, thereby fixing the first connecting seat and the second connecting seat together.

[0024] In some embodiments, the probe holder includes a protective cover, a probe support, and a plurality of probe assemblies; each probe assembly includes an ultrasonic probe having at least two degrees of freedom of motion.

[0025] One end of the protective cover is open, and the probe support fits inside the open end of the protective cover to close the open end; and the probe support is provided with a plurality of channel holes that pass through the opposite ends of the probe support and communicate with the internal space of the protective cover; one of the channel holes is used to insert a probe assembly, and the probe assembly can move back and forth along the channel hole relative to the protective cover and the probe support in the direction of entering and exiting the protective cover.

[0026] In some embodiments, the probe assembly further includes a probe slide and a probe frame, wherein a first end of the probe slide passes through the channel hole and moves back and forth along the channel hole; the probe frame is rotatably disposed on the second end of the probe slide, and the ultrasound probe is disposed on the probe frame and is rotatable relative to the probe frame.

[0027] In some embodiments, the probe assembly further includes a constant force spring; the constant force spring is disposed at the first end of the probe slide rod and connected to the probe support, so that the probe slide rod has a constant tendency force to move in the direction of the outer side of the protective cover.

[0028] The present invention also provides a method for inspecting a reactor pressure vessel, using the above-mentioned reactor pressure vessel inspection equipment, the method comprising the following steps:

[0029] S1. Install the reactor pressure vessel inspection equipment on the flange face of the pressure vessel body;

[0030] S2. The lifting mechanism of the reactor pressure vessel inspection equipment is activated, and the pipe scanning arm and the two multi-degree-of-freedom robotic arm probe frames are lowered to the position to be scanned inside the cylinder.

[0031] S3. The tube scanning arm and the two multi-degree-of-freedom robotic arm probe frames perform synchronous and parallel scanning.

[0032] The scanning positions of the pipe inspection arm include at least one of the following: the safety end weld of the inlet pipe, the safety end weld of the outlet pipe, the extended section of the inner rounded corner of the inlet pipe, the extended section of the inner rounded corner of the outlet pipe, the pipe side of the weld connecting the inlet pipe and the cylinder, the pipe side of the weld connecting the outlet pipe and the cylinder, the weld overlay of the inlet pipe, the weld overlay of the outlet pipe, the inner rounded corner of the inlet pipe, and the inner rounded corner of the outlet pipe.

[0033] The scanning positions of the multi-degree-of-freedom robotic arm probe frame include at least one of the following: the weld between the inlet pipe and the cylinder on the cylinder side; the weld between the outlet pipe and the cylinder on the cylinder side; the inner radius of the outlet; the circumferential weld of the cylinder; the circumferential weld of the bottom head; and the high-throughput zone of the reactor core.

[0034] The beneficial effects of this invention are as follows: By setting up two multi-degree-of-freedom robotic arm probe frames and a pipe scanning arm to cooperate in scanning the reactor pressure vessel, the multi-degree-of-freedom robotic arm probe frames and the pipe scanning arm can scan synchronously and in parallel, reducing scanning time, improving work efficiency, and greatly reducing the critical path time for nuclear power plant overhauls. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0036] Figure 1 This is a schematic diagram of the structure of a reactor pressure vessel inspection device according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the lifting mechanism and rotating mechanism in a reactor pressure vessel inspection device according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the rotating mechanism in a reactor pressure vessel inspection device according to an embodiment of the present invention;

[0039] Figure 4 yes Figure 3 A schematic cross-sectional view of the rotating mechanism shown.

[0040] Figure 5 This is a schematic diagram of the reactor pressure vessel inspection equipment according to an embodiment of the present invention after removing the support frame and lifting mechanism;

[0041] Figure 6 yes Figure 5 Schematic diagram of the structure of the central tube scanning arm;

[0042] Figure 7 yes Figure 5 A schematic diagram of the probe frame of a multi-degree-of-freedom robotic arm;

[0043] Figure 8 This is a schematic diagram (partial cross-section) of the cooperation structure between the probe holder and the rotating disk of a multi-degree-of-freedom robotic arm;

[0044] Figure 9 This is a schematic diagram of an embodiment of the probe holder in the multi-degree-of-freedom robotic arm probe holder of the present invention;

[0045] Figure 10 yes Figure 9 The diagram shows the structure of the probe holder after the protective cover has been removed.

[0046] Figure 11 yes Figure 10 A schematic diagram of the structure of the probe assembly;

[0047] Figure 12 This is a schematic diagram of the reactor pressure vessel inspection equipment in the cylinder according to an embodiment of the present invention (the support frame and lifting mechanism are omitted). Detailed Implementation

[0048] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0049] The reactor pressure vessel inspection equipment of the present invention is used to perform non-destructive testing on the welds, bolt holes, weld overlays, and base metal of the neutron high flux region of the reactor pressure vessel.

[0050] like Figure 1As shown, a reactor pressure vessel inspection device according to an embodiment of the present invention may include a support frame 10, a lifting mechanism 20 mounted on the support frame 10, a rotating mechanism 30 mounted on the lifting mechanism 20, a pipe inspection arm 40 mounted on the rotating mechanism 30, and two multi-degree-of-freedom robotic arm probe frames 50.

[0051] The support frame 10 is installed on the flange face of the pressure vessel (RPV) shell to achieve stable positioning of the entire equipment on the shell. The lifting mechanism 20 is suspended on the shell by being mounted on the support frame 10 and is coaxial with the shell, allowing it to move up and down relative to the support frame 10 and the shell along the central axis of the shell. The rotating mechanism 30 is installed on the lower part of the lifting mechanism 20 facing the shell, allowing it to move up and down with the lifting mechanism 20 and rotate relative to it. The pipe scanning arm 40 and two multi-degree-of-freedom robotic arm probe holders 50 are used for synchronous and parallel scanning of the shell. The pipe scanning arm 40 and the two multi-degree-of-freedom robotic arm probe holders 50 are respectively installed below the rotating mechanism 30, moving up and down and rotating with the rotating mechanism 30 to ensure thorough scanning of the area to be scanned.

[0052] Specifically, the support frame 10 may structurally include a connecting bracket 11 and four support legs 12. The four support legs 12 are respectively used to stand upright on the flange surface of the cylinder. The connecting bracket 11 is connected between the four support legs 12 and can span across the flange surface of the cylinder. Each support leg 12 has a support sleeve 13 at its lower part, and the support sleeve 13 can be sleeved and engaged with the guide post on the flange surface.

[0053] When the support frame 10 is placed on the flange face of the cylinder, the four support legs 12 are distributed circumferentially along the flange face. Two of the support legs 12 located at opposite corners are respectively engaged with the guide posts on the flange face through the support sleeves 13. The other two support legs 12 can be connected to the flange holes on the flange face through their respective support sleeves 13, and can be further locked with bolts.

[0054] In a preferred embodiment, the connecting bracket 11 of the support frame 10 is I-shaped, and the four free ends located around the perimeter are respectively used to connect the support legs 12.

[0055] The lifting mechanism 20 is vertically connected to the support bracket 11, and the central axis of the lifting mechanism 20 is coaxial with the central axis of the cylinder. The support bracket 11 may be provided with a bracket hole to cooperate with the lifting mechanism 20.

[0056] Furthermore, if Figure 1 and Figure 2As shown, the lifting mechanism 20 may include a lifting column 21, which is vertically connected to the connecting bracket 11 and passes through the connecting bracket 11. One end (upper end) of the lifting column 21 is located on the upper side of the connecting bracket 11, and the other end (lower end) is located on the lower side of the connecting bracket 11 and faces the inside of the cylinder.

[0057] The lower end of the lifting column 21 can be provided with several sleeves that are sequentially connected. By the relative extension or retraction of the sleeves, the lower end of the lifting column 21 can move up and down through extension and retraction. The rotating mechanism 30 is installed at the lower end of the lifting column 21 and can move up and down relative to the support frame 10 and the cylinder as the lower end of the lifting column 21 extends and retracts.

[0058] Corresponding to the extension and retraction of the lower end of the lifting column 21, the lifting mechanism 20 further includes a winch mechanism 22 connected thereto, which pulls up or lowers the sleeve at the lower end of the lifting column 21, so that the lower end of the lifting column 21 performs an extension and retraction action.

[0059] The rotating mechanism 30 is mounted on the lower end of the lifting column 21, which is located below the connecting bracket 11. In some embodiments, the rotating mechanism 30 includes a rotating disk 31, which can be driven to rotate by a motor or the like. The rotating disk 31 has a plurality of spaced mounting holes for mounting the tube scanning arm 40 and the multi-degree-of-freedom robotic arm probe holder 50 below the rotating disk 31. For example, the plurality of mounting holes are evenly spaced along the circumference of the rotating disk 31. The tube scanning arm 40 can be parallel to the diameter of the rotating disk 31 and laterally connected to the lower part of the rotating disk 31 by engaging with two mounting holes at 180°. The two multi-degree-of-freedom robotic arm probe holders 50 can be connected to the lower part of the rotating disk 31 by engaging with mounting holes located on both sides of the tube scanning arm 40, and are located on opposite sides of the tube scanning arm 40.

[0060] Furthermore, such as Figures 2 to 4 As shown, the rotating mechanism 30 also includes a support plate 32, a hollow cable carrier 33, a torque motor 34 with an absolute encoder, and a connecting cylinder 35. The cable carrier 33 and the connecting cylinder 35 are connected to opposite sides of the support plate 32, and the support plate 32 is provided with a through hole 320 to connect the cable carrier 33 and the connecting cylinder 35; the end of the cable carrier 33 away from the support plate 32 is fixedly connected to the lifting column 21, so that the cable carrier 33, the support plate 32, and the connecting cylinder 35 are fixedly connected to the lower end of the lifting column 21.

[0061] The upper end of the cable carrier 33 can be connected to or integrally formed with a cylindrical column 331 for fixed connection with the lifting column 21. The cable carrier 33 is a hollow shell structure, and the internal space can be used for cable passage and accommodation. At least one side of the cable carrier 33 is provided with a cable passage hole 330 communicating with its internal space for cable entry and exit. The rotating disk 31 is sleeved on the outer periphery of the connecting cylinder 35 and can rotate relative to the connecting cylinder 35. The torque motor 34 is mounted on the support plate 32, connected to and driving the rotating disk 31 to rotate.

[0062] At least one bearing 36 is fitted between the rotating disk 31 and the connecting cylinder 35 to reduce the coefficient of friction between the rotating disk 31 and the connecting cylinder 35.

[0063] The torque motor 34 can be connected to and drive the rotating disk 31 to rotate via gears, etc. The torque motor 34 is equipped with an absolute encoder, which is used to pick up and feed back the rotation angle and rotation speed information of the torque motor 34. The remote control system receives the above information and can process it to obtain the rotation angle and rotation speed of the rotating disk 31, thereby monitoring the rotation angle and speed of the scanning arm 40 and the multi-degree-of-freedom robotic arm probe frame 50 during scanning.

[0064] Furthermore, the support plate 32 is equipped with a connection unit 37 integrating several connectors. The connecting cables of the tube scanning arm 40 and the multi-degree-of-freedom robotic arm probe frame 50 pass through the cable tray 33 and are connected to the connectors of the connection unit 37. The connection unit 37 is then connected to the control system via connecting cables, realizing the connection between the tube scanning arm 40 and the multi-degree-of-freedom robotic arm probe frame 50 and the control system for monitoring, power supply, etc.

[0065] The cable carrier 33 in the rotating mechanism 30 prevents the connecting cables of the inspection arm 40 and the multi-degree-of-freedom robotic arm probe frame 50 from becoming tangled or pulled as the rotating disk 31 rotates. The rotating disk 31 is an open disc structure without a sealed space. After the rotating mechanism 30 operates inside the pressure vessel, the coolant inside the pressure vessel will not accumulate in the rotating disk 31, cable carrier 33, or other structures, and the accumulation of radioactive materials within them will also be avoided or reduced.

[0066] Corresponding to the external connection of the connecting cable on the connecting unit 37, the reactor pressure vessel inspection equipment also includes a cable winding winch 60 mounted on the lifting mechanism 20. (Reference) Figure 1The cable winding winch 60 can be fixed to the lifting column 21 or the winch mechanism 22. The lifting end of the cable winding winch 60 is equipped with a cable rack 61 for suspending cables. External connecting cables are suspended on the cable rack 61, with one end connected to the connector of the connecting unit 37 and the other end used for connecting to the external control system. The cable winding winch 60 and its cable rack 61 make cable arrangement more convenient, and as the lower end of the lifting column 21 extends and retracts, the cable winding winch 60 can simultaneously wind and unwind the cable, preventing tangling and pulling problems.

[0067] Combination Figure 3 , Figure 5 and Figure 6 The tube scanning arm 40 is installed below the rotary disk 31 in the diameter direction, and the two multi-degree-of-freedom robotic arm probe frames 50 are respectively located on both sides of the tube scanning arm 40 and installed below the rotary disk 31.

[0068] The scanning arm 40 may further include a scanning robotic arm 41 mounted below the rotary disk 31, a rotating part 42 rotatably mounted at one end of the scanning robotic arm 41, and a plurality of scanning components 43 disposed on the rotating part 42. The scanning robotic arm 41 may move back and forth relative to the rotary disk 31 in the radial direction of the pressure vessel's cylinder, thereby driving the rotating part 42 and the scanning components 43 at its end to move back and forth in the radial direction.

[0069] The reciprocating movement of the scanning robotic arm 41 can be achieved through telescopic movement. The scanning robotic arm 41 can be fixed below the rotating disk 31 by at least one suspension bracket 44 engaging with a mounting hole. The rotating part 42 at the end of the scanning robotic arm 41 can rotate via a motor or other driving component. Preferably, a plurality of scanning components 43 can be distributed circumferentially on the outer peripheral surface of the rotating part 42. The scanning components 43 may include a camera, a ranging probe, etc.

[0070] like Figure 5 As shown, the multi-degree-of-freedom robotic arm probe holder 50 may further include a six-degree-of-freedom robotic arm 51 (also known as a six-axis robotic arm) and a probe holder 52.

[0071] The six-degree-of-freedom robotic arm 51 is mounted below the rotating mechanism 30 (rotating disk 31) with its first joint 511 parallel to the central axis of the pressure vessel and through the first quick-release structure. The probe holder 52 is detachably mounted on the sixth joint 516 of the six-degree-of-freedom robotic arm 51 away from the rotating mechanism 30 through the second quick-release structure.

[0072] The first quick-assembly structure facilitates rapid assembly and disassembly of the six-DOF robotic arm 51 within the RPV water tank; the second quick-assembly structure facilitates rapid assembly and disassembly of the probe holder 52 from the six-DOF robotic arm 51 within the RPV water tank. These quick-assembly and disassembly operations can be completed in one step, without requiring the equipment to be submerged in water, thus enabling all RPV inspection items to be performed. The inspection of the connecting pipe sections, which accounts for 70% of the inspection workload, is completed by the connecting pipe scanning arm 40 and the multi-DOF robotic arm probe holder 50, and both can be inspected simultaneously, significantly reducing inspection time and improving work efficiency.

[0073] refer to Figure 7 and Figure 8 In some embodiments, the first quick-release structure includes a positioning post 101, a positioning hole 102 adapted to the positioning post 101, a positioning pin 103, a pin hole 104 adapted to the positioning pin 103, and a locking member 105, etc.

[0074] The positioning post 101 is mounted on the first joint 511 of the six-degree-of-freedom robotic arm 51, and the positioning hole 102 is mounted on the rotary disk 31 of the rotating mechanism 30. When the six-degree-of-freedom robotic arm 51 is docked with the rotary disk 31, the positioning post 101 is inserted into the positioning hole 102. The positioning post 101 is also provided with a screw hole 106 for engaging with the locking member 105. The positioning hole 102 is realized by the mounting hole on the rotary disk 31.

[0075] The positioning pin 103 protrudes from the first joint 511 and is located on at least one side of the positioning post 101. The positioning pin 103 is smaller than the positioning post 101 in both height and diameter, and is mainly used for alignment before the positioning post 101 and the positioning hole 102 are connected. The pin hole 104 is provided on the rotating disk 31 and is located on at least one side of the positioning hole 102, for the insertion of the positioning pin 103.

[0076] When the six-degree-of-freedom robotic arm 51 is docked with the rotary table 31, the positioning pin 103 is first aligned with the pin hole 104 to confirm the installation direction of the six-degree-of-freedom robotic arm 51. The positioning post 101 is inserted into the positioning hole 102 from one side and fits into the positioning hole 102, while the positioning pin 103 fits into the pin hole 104. The locking member 105 is inserted into the screw hole 106 of the positioning post 101 from the other side of the positioning hole 102 and fastened. The locking member 105 can be, but is not limited to, a bolt.

[0077] refer to Figure 8 and Figure 9 In some embodiments, the second quick-assembly structure includes a first connecting seat 210 disposed on the sixth joint 516 of the six-degree-of-freedom robotic arm 51, a second connecting seat 220 disposed on the probe holder 52, and a docking assembly.

[0078] The first connecting seat 210 is provided with an axially connected mating hole 211 and a screw hole 212; the inner diameter of the mating hole 211 is larger than that of the screw hole 212, and the mating hole 211 passes through one end of the first connecting seat 210, while the screw hole 212 passes through the opposite end of the first connecting seat 210.

[0079] The second connecting seat 220 has a mating post 221 on one side that is adapted to the mating hole 211. The second connecting seat 220 also has a central channel 222 that extends through the mating post 221. The central channel 222 includes a first channel extending through the second connecting seat 220 and a second channel extending through the mating post 221. A boss is provided at the connection between the first channel and the second channel. The mating assembly is inserted into the central channel 222 and can move and rotate axially relative to the central channel 222.

[0080] The docking assembly may specifically include an axially connected rotating operating part 223 and a screw 224. The diameter of the rotating operating part 223 is larger than the diameter of the screw 224, and the rotating operating part 223 can engage with a first channel of the central channel 222, entering and exiting the first channel. The screw 224 can pass through the first channel and the second channel, moving back and forth in the central channel 222 as the rotating operating part 223 enters and exits the first channel. The end of the screw 224 away from the rotating operating part 223 is confined within the second channel by engaging with a boss. When the rotating operating part 223 moves back and forth along the axial direction of the central channel 222, the end of the screw 224 can extend out of the second channel or retract into the second channel.

[0081] When the first connecting seat 210 and the second connecting seat 220 are mated, the mating post 221 is inserted into the mating hole 211, and the mating assembly has the screw 224 facing the screw hole 212 of the first connecting seat 210. At this time, the initial mating of the first connecting seat 210 and the second connecting seat 220 can be completed. By rotating the rotating operating part 223, the screw 224 is locked in the screw hole 212. At the same time, with the rotation of the rotating operating part 223 and the engagement of the screw 224 and the screw hole 212, the rotation is converted into the axial movement of the connecting assembly until the screw 224 is locked in the screw hole 212, thus fixing the first connecting seat 210 and the second connecting seat 220 together.

[0082] In the second quick-assembly structure, the rotating operating part 223 is a cylindrical structure with an internal concave-convex structure for cooperating with the operating end of the long rod tool, so that the operator can enter the RPV water tank from outside the pressure vessel through the long rod tool to quickly assemble and disassemble the probe frame 52 on the six-degree-of-freedom robotic arm 51.

[0083] The probe holder 52 can be implemented using existing technology. Alternatively, to reduce the workload of on-site foreign object prevention, and thus reduce the time and radiation dose to personnel caused by foreign object prevention inspections, the probe holder 52 can be a probe holder with foreign object prevention function.

[0084] like Figures 9-11 As shown, the probe holder 52 includes a protective cover 1, a probe support 2, and several probe assemblies 3; each probe assembly 3 includes at least two ultrasonic probes 300 with two degrees of freedom of motion.

[0085] One end of the protective cover 1 is open, and the probe support 2 is fitted inside the open end of the protective cover 1 to close the open end. Furthermore, the probe support 2 is provided with a plurality of channel holes 201 that penetrate through opposite ends of the probe support 2 and communicate with the internal space of the protective cover 1; one channel hole 201 is used to insert a probe assembly 3, and the probe assembly 3 can move back and forth along the channel hole 201 relative to the protective cover 1 and the probe support 2 in the direction of entering and exiting the protective cover 1.

[0086] On the probe support 2, several channel holes 201 are arranged along the length of the probe support 2, and can form one row, two rows or more.

[0087] The probe support 2 is preferably detachably fitted to the open end of the protective cover 1, which facilitates the disassembly, replacement, and maintenance of the probe assembly 3.

[0088] Each probe assembly 3 may include an ultrasonic probe 300, a probe slide bar 301, and a probe frame 302. The probe slide bar 301 has a first end and a second end, the first end of which passes through a channel hole 201 and can move back and forth along the channel hole 201 in the direction of entering and exiting the protective cover 1. The probe frame 302 is rotatably mounted on the second end of the probe slide bar 301 by means of a rotating component or the like, and the ultrasonic probe 300 is mounted on the probe frame 302 by a rotating shaft or the like and can rotate relative to the probe frame 302.

[0089] by Figure 9 and Figure 10 The probe holder 52 is positioned with the ultrasonic probe 300 facing upwards. The probe slide bar 301 can move up and down relative to the protective cover 1 and the probe support 2, which in turn causes the probe frame 302 and the ultrasonic probe 300 on its second end to move up and down as well.

[0090] A limiting pin 202 can also be provided between the probe slide rod 301 and the probe support 2 to constrain the movement stroke of the probe slide rod 301. The limiting pin 202 is fixed inside the probe support 2 and passes through or is fitted at one end into the limiting groove 304 opened on the probe slide rod 301. When the probe slide rod 301 moves up and down in the channel hole 201, the limiting pin 202 also moves in the limiting groove 304. When the limiting pin abuts against the upper or lower end of the limiting groove 304, it restricts the probe slide rod 301 from continuing to move in the current direction, thereby achieving the effect of constraining the movement stroke of the probe slide rod 301.

[0091] The rotation direction of the probe frame 302 relative to the probe slide bar 301 is perpendicular to the rotation direction of the ultrasonic probe 300 relative to the probe frame 302. The rotation of the probe frame 302 also causes the ultrasonic probe 300 to rotate relative to the probe slide bar 301, giving the ultrasonic probe 300 two perpendicularly orthogonal rotational degrees of freedom on the probe slide bar 301, ensuring close contact between the ultrasonic probe 300 and the area to be scanned. Combined with the back-and-forth movement of the probe slide bar 301, the ultrasonic probe 300 has three degrees of freedom.

[0092] The probe assembly 3 also includes a constant force spring 303; the constant force spring 303 is disposed at the first end of the probe slide rod 301 and connected to the probe support 2, so that the probe slide rod 301 has a constant tendency force to move outward in the direction of the protective cover 1.

[0093] In the aforementioned probe holder 52, a protective cover 1 is provided to form a covered space to accommodate the probe support 2 and the lower structure of the probe assembly 3, thereby reducing the number of exposed external parts and thus reducing the difficulty of preventing foreign objects from entering.

[0094] The protective cover 1 has a bracket on its side for connecting to the six-degree-of-freedom robotic arm 51, and the second connecting seat 220 of the second quick-release structure is disposed on the bracket.

[0095] The reactor pressure vessel inspection method implemented by the reactor pressure vessel inspection equipment of the present invention is described in reference to... Figure 1 and Figure 12 The inspection method may include the following steps:

[0096] S1. Install the reactor pressure vessel inspection equipment on the flange face of the pressure vessel body 400.

[0097] S2. The lifting mechanism 20 of the reactor pressure vessel inspection equipment is activated, lowering the pipe scanning arm 40 and the two multi-degree-of-freedom robotic arm probe frames 50 to the position to be scanned inside the cylinder 400.

[0098] S3, the receiver scanning arm 40 and the two multi-degree-of-freedom robotic arm probe frames 50 perform synchronous parallel scanning.

[0099] The areas to be inspected within the pressure vessel's shell 400 include: the flange threaded hole at the top flange face of the shell, the flange ligament area, the weld connecting the flange and the nozzle section (S / C200 circumferential weld), the weld connecting the inlet nozzle and the shell (inlet SET-IN weld), the weld at the safety end of the inlet nozzle (nozzle and safety end, safety end and main pipeline), the extended section of the inner rounded corner of the inlet nozzle, the weld at the safety end of the outlet nozzle (nozzle and safety end, safety end and main pipeline), the extended section of the inner rounded corner of the outlet nozzle, the weld connecting the outlet nozzle and the shell (outlet SET-IN weld), the inner rounded corner of the outlet (R19 inner rounded corner), the circumferential weld between the nozzle section and the shell section (S / C201 circumferential weld), the high-flux area of ​​the core, the circumferential weld between the shell section and the shell section (S / C202 circumferential weld), and the circumferential weld of the bottom head (S / C204 weld), etc.

[0100] The scanning positions of the pipe inspection arm 40 include at least one of the following: the safety end weld of the inlet pipe, the safety end weld of the outlet pipe, the weld connecting the safety end to the main pipe, the extended section of the inner rounded corner of the inlet pipe, the extended section of the inner rounded corner of the outlet pipe, the pipe side of the weld connecting the inlet pipe to the cylinder, the pipe side of the weld connecting the outlet pipe to the cylinder, the weld overlay of the inlet pipe, the weld overlay of the outlet pipe, the inner rounded corner of the inlet pipe (excluding R19 inner rounded corner), and the inner rounded corner of the outlet pipe (excluding R19 inner rounded corner).

[0101] The scanning positions of the multi-degree-of-freedom robotic arm probe frame 50 include at least one of the following: the weld between the inlet nozzle and the cylinder on the cylinder side; the weld between the outlet nozzle and the cylinder on the cylinder side; the inner radius of the outlet (R19 inner radius); the circumferential weld of the cylinder; the circumferential weld of the bottom head; the high-throughput zone of the core; the flange threaded hole; and the flange ligament zone.

[0102] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A reactor pressure vessel inspection device, characterized in that, It includes a support frame for mounting on the flange face of the cylinder of a pressure vessel, a lifting mechanism mounted on the support frame and coaxial with the cylinder, a rotating mechanism mounted on the lifting mechanism facing the lower part of the cylinder, a pipe scanning arm mounted below the rotating mechanism, and two multi-degree-of-freedom robotic arm probe frames. The lifting mechanism is movable relative to the support frame, driving the rotating mechanism and its mounted tube scanning arm and multi-degree-of-freedom robotic arm probe frame to move up and down along the central axis of the cylinder; the rotating mechanism is used to drive the tube scanning arm and multi-degree-of-freedom robotic arm probe frame to rotate around the central axis of the cylinder; the tube scanning arm and the two multi-degree-of-freedom robotic arm probe frames are used to perform synchronous parallel scanning of the cylinder; The support frame includes four support legs for standing upright on the flange surface of the cylinder, and a connecting bracket connecting the four support legs and spanning across the flange surface of the cylinder; the four support legs are distributed circumferentially along the flange surface, wherein the two support legs located at diagonal positions are respectively used to cooperate with guide posts on the flange surface. The lifting mechanism includes a lifting column that passes through the connecting bracket perpendicularly; the two ends of the lifting column are located on the upper and lower sides of the connecting bracket, respectively; the rotating mechanism is installed on the lower end of the lifting column located on the lower side of the connecting bracket; the lower end of the lifting column is retractable, driving the rotating mechanism to move up and down.

2. The reactor pressure vessel inspection equipment according to claim 1, characterized in that, The rotating mechanism includes a support plate, a hollow cable carrier, a torque motor with an absolute encoder, a connecting cylinder, and a rotating disk. The cable carrier and the connecting cylinder are connected to opposite sides of the support plate, and the support plate has a through hole connecting the cable carrier and the connecting cylinder; the end of the cable carrier away from the support plate is fixedly connected to the lifting column; the rotating disk is sleeved on the outer periphery of the connecting cylinder and can rotate relative to the connecting cylinder; the torque motor is set on the support plate, connected to and drives the rotating disk to rotate; The rotating disk is provided with a number of spaced mounting holes for mounting the tube scanning arm and the multi-degree-of-freedom robotic arm probe frame under the rotating disk.

3. The reactor pressure vessel inspection equipment according to claim 2, characterized in that, At least one side of the cable carrier is provided with a cable-carrying hole that communicates with its internal space. The support plate is provided with a connection unit integrating several connectors. The connecting cables of the tube scanning arm and the multi-degree-of-freedom robotic arm probe frame pass through the cable tray and are connected to the connectors of the connection unit.

4. The reactor pressure vessel inspection equipment according to claim 3, characterized in that, The reactor pressure vessel inspection equipment also includes a cable winding winch mounted on the lifting mechanism. The lifting end of the cable winding winch is provided with a cable rack for suspending cables. External connecting cables are suspended on the cable rack, with one end connected to the connector of the connecting unit and the other end used for external control system connection.

5. The reactor pressure vessel inspection equipment according to claim 1, characterized in that, The multi-degree-of-freedom robotic arm probe holder includes a six-degree-of-freedom robotic arm and a probe holder; The six-degree-of-freedom robotic arm is mounted below the rotating mechanism with its first joint parallel to the central axis of the cylinder and through a first quick-release structure. The probe holder is detachably mounted on the sixth joint of the six-degree-of-freedom robotic arm away from the rotating mechanism through a second quick-release structure.

6. The reactor pressure vessel inspection equipment according to claim 5, characterized in that, The first quick-assembly structure includes a positioning post disposed on the first joint of the six-degree-of-freedom robotic arm, a positioning hole adapted to the positioning post and disposed on the rotating mechanism, a positioning pin protruding from the first joint and located on at least one side of the positioning post, a pin hole disposed on the rotating mechanism and located on at least one side of the positioning hole, and a locking member; the positioning post is inserted into the positioning hole from one side and fitted into the positioning hole, while the positioning pin is fitted into the pin hole, and the locking member is inserted into the positioning hole from the other side and fastened to the positioning post.

7. The reactor pressure vessel inspection equipment according to claim 5, characterized in that, The second quick-assembly structure includes a first connecting seat disposed on the sixth joint of the six-degree-of-freedom robotic arm, a second connecting seat disposed on the probe frame, and a docking assembly; The first connecting seat is provided with an axially connected mating hole and a screw hole; the second connecting seat is provided with a mating post on one side that is adapted to the mating hole, and the second connecting seat is also provided with a central channel that extends through the mating post. The mating assembly is inserted into the central channel and can move and rotate axially relative to the central channel; the mating assembly includes an axially connected rotating operating part and a screw. When the first connecting seat and the second connecting seat are mated, the mating post is engaged in the mating hole, and the mating assembly rotates with the screw facing the screw hole, so that the screw is engaged in the screw hole, thereby fixing the first connecting seat and the second connecting seat together.

8. The reactor pressure vessel inspection equipment according to claim 5, characterized in that, The probe holder includes a protective cover, a probe support, and several probe assemblies; each probe assembly includes an ultrasonic probe with at least two degrees of freedom of motion. One end of the protective cover is open, and the probe support fits inside the open end of the protective cover to close the open end; and the probe support is provided with a plurality of channel holes that pass through the opposite ends of the probe support and communicate with the internal space of the protective cover; one of the channel holes is used to insert a probe assembly, and the probe assembly can move back and forth along the channel hole relative to the protective cover and the probe support in the direction of entering and exiting the protective cover.

9. The reactor pressure vessel inspection equipment according to claim 8, characterized in that, The probe assembly further includes a probe slide rod and a probe frame. A first end of the probe slide rod passes through the channel hole and moves back and forth along the channel hole. The probe frame is rotatably mounted on a second end of the probe slide rod. The ultrasound probe is mounted on the probe frame and is rotatable relative to the probe frame. And / or... The probe assembly also includes a constant force spring; the constant force spring is disposed at the first end of the probe slide rod and connected to the probe support, so that the probe slide rod has a constant tendency force to move outward in the direction of the protective cover.

10. The reactor pressure vessel inspection equipment according to any one of claims 1-9, characterized in that, The tube scanning arm includes a scanning robotic arm mounted below the rotating mechanism and capable of reciprocating radially relative to the rotating mechanism in the cylinder, a rotating part rotatably mounted at one end of the scanning robotic arm, and a plurality of scanning components disposed on the rotating part.

11. A method for inspecting a reactor pressure vessel, characterized in that, The reactor pressure vessel inspection method using the reactor pressure vessel inspection equipment according to any one of claims 1-10 includes the following steps: S1. Install the reactor pressure vessel inspection equipment on the flange face of the pressure vessel body; S2. The lifting mechanism of the reactor pressure vessel inspection equipment is activated, and the pipe scanning arm and the two multi-degree-of-freedom robotic arm probe frames are lowered to the position to be scanned inside the cylinder. S3. The tube scanning arm and the two multi-degree-of-freedom robotic arm probe frames perform synchronous and parallel scanning. The scanning positions of the pipe inspection arm include at least one of the following: the safety end weld of the inlet pipe, the safety end weld of the outlet pipe, the extended section of the inner rounded corner of the inlet pipe, the extended section of the inner rounded corner of the outlet pipe, the pipe side of the weld connecting the inlet pipe and the cylinder, the pipe side of the weld connecting the outlet pipe and the cylinder, the weld overlay of the inlet pipe, the weld overlay of the outlet pipe, the inner rounded corner of the inlet pipe, and the inner rounded corner of the outlet pipe. The scanning positions of the multi-degree-of-freedom robotic arm probe frame include at least one of the following: the weld between the inlet pipe and the cylinder on the cylinder side; the weld between the outlet pipe and the cylinder on the cylinder side; the inner radius of the outlet; the circumferential weld of the cylinder; the circumferential weld of the bottom head; and the high-throughput zone of the reactor core.

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