Pipeline electric spark demolition and repair equipment and pipeline electric spark demolition and repair method

Abstract

The present invention provides a pipeline electric spark removal and repair device and a pipeline electric spark removal and repair method. The pipeline electric spark removal and repair device includes a radial motion structure, a circumferential motion structure, an axial motion structure, a quick-release connection structure, a working structure, and a lifting support platform. The working structure includes a cutting and grinding assembly or a grinding and quick-release repair electrode. The cutting and grinding assembly is used to grind and remove the material of the upper end of the thermal insulation sleeve. The cutting and grinding and quick-release repair electrode of the thermal insulation sleeve is used to polish and repair the inner wall of the CRDM tube seat that is worn. The present invention solves the problem of difficulty in removing and cutting the thermal insulation sleeve and repairing the inner wall of the CRDM tube seat by using the cutting and grinding assembly and the grinding and quick-release repair electrode. It also avoids the structural damage to the CRDM tube seat caused by conventional cutting methods.

Description

Technical Field

[0001] The present invention relates to a technology in the field of nuclear power plant pipeline demolition and repair, specifically, to a pipeline electric spark demolition and repair device and a pipeline electric spark demolition and repair method, and more particularly, to a narrow and long pipeline electric spark demolition and repair device and method with a novel composite electrode. Background Art

[0002] The safe construction and development of nuclear power is of great significance to my country's energy development and nuclear industry development. The construction and development of nuclear power equipment is crucial for ensuring national energy needs, protecting energy security, safeguarding the ecological environment, achieving power supply structure reform, and achieving sustainable development in the power generation industry. The nuclear reactor pressure vessel, a sealed container that houses the nuclear reactor and withstands its immense operating pressures, is a crucial component of nuclear power generation. To ensure the safe, efficient, and reliable operation of nuclear power plants, regular inspection, removal, and replacement of the thermal insulation sleeves within the pressure vessel are crucial. Repair of the inner wall of the control rod drive mechanism (CRDM) sockets is particularly important. The thermal insulation sleeves are shaped pipes with large ends and a narrow middle, sealed at the top. Therefore, removal can only be performed from within the reactor vessel, entering the thermal insulation sleeve from the bottom up and destructively separating the large "bowl-shaped" end caps at the top to achieve pipe removal. Because the insulation sleeve is typically suspended vertically, its inner wall diameter is only 60-70 mm. The lower end is 1.7-1.8 meters above the ground, while the upper bowl-shaped end is approximately 3.6 meters above the ground. Furthermore, the internal pipe is fluid, with radial clearance and axial movement. Under these conditions, how to remove the sleeve without damaging the inner wall of the CRDM socket after the machining platform reaches the machining position inside the insulation sleeve, and how to repair the inner wall of the CRDM socket, are urgent challenges.

[0003] Currently, depending on different needs, the main methods for cutting pipes include laser cutting, water jet cutting, electrospark machining (EDM), and conventional mechanical cutting. Laser cutting is clean, efficient, and highly controllable, but it lacks precise penetration testing, making it difficult to avoid structural damage to the CRDM pipe socket. Water jet cutting uses high-pressure water flow to impart high-speed impact force to abrasive particles, enabling collision cutting of pipes. However, the water jet cannot be stopped immediately after penetrating the pipe, inevitably causing structural damage to the CRDM pipe socket. Furthermore, the impact of the high-pressure water jet on the inner wall of the pipe can cause the non-fixed pipe to vibrate, affecting machining accuracy. Conventional mechanical machining methods are difficult to operate within narrow and non-fixed pipes.

[0004] Patent document CN 113843517 A discloses a laser cutting industrial robot for pipe cutting and a cutting method thereof. The robot comprises a housing with a support mechanism disposed in the middle of the housing, an adjustment mechanism disposed in the middle of one sidewall of the housing, a cutting device disposed at the top of the adjustment mechanism, a drive mechanism disposed on each of the bottom sidewalls of the housing, and a control panel disposed eccentrically on one sidewall of the housing. The drive mechanism is configured as a power source for the housing to climb within the pipe. However, this solution still relies on a laser cutting method, making it difficult to avoid structural damage to the CRDM pipe socket. Summary of the Invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a pipeline electric spark demolition and repair device and a pipeline electric spark demolition and repair method.

[0006] According to the present invention, a pipeline electric spark removal and repair device includes a radial motion structure, a circumferential motion structure, an axial motion structure, a quick-release connection structure, a working structure, a lifting support platform, a first shell, and a second shell;

[0007] The axial motion structure is connected to the lifting support platform, the circumferential motion structure is installed on the lifting support platform, the radial motion structure is installed on the circumferential motion structure, the quick-release connection structure is installed on the radial motion structure, and the working structure is detachably installed on the quick-release connection structure;

[0008] The axial motion structure can drive the lifting support platform to drive the circumferential motion structure to move axially, the circumferential motion structure can drive the radial motion structure to rotate axially around the circumferential motion structure, and the radial motion structure can drive the quick-release connection structure to cause the working structure to move radially along the radial motion structure;

[0009] The quick-release connection structure includes a working platform and a quick-release electrode holder. The working platform is mounted on the radial motion structure, and the quick-release electrode holder is mounted on the working platform. The working structure is detachably mounted on the quick-release electrode holder.

[0010] The working structure includes a cutting and grinding assembly and a grinding and quick-release repair electrode; the cutting and grinding assembly is used to grind and remove the material of the upper end of the insulation sleeve and cut the insulation sleeve; the grinding and quick-release repair electrode is used to polish and repair the worn inner wall of the CRDM tube seat.

[0011] The cutting and grinding assembly includes a cutting and grinding composite quick-release electrode, an electrode push rod mounting plate, and a telescopic electrode block; the cutting and grinding composite quick-release electrode is detachably mounted on the quick-release electrode holder, the electrode push rod mounting plate and the telescopic electrode block are mounted on the cutting and grinding composite quick-release electrode, the electrode push rod is mounted on the electrode push rod mounting plate, and the electrode push rod is connected to the telescopic electrode block, and can drive the telescopic electrode block to move;

[0012] The grinding quick-release repair electrode is detachably mounted on the quick-release electrode holder;

[0013] The axial motion structure is installed in the first shell, the second shell is sleeved on the outside of the lifting support platform, and the first shell is tightly connected to the second shell;

[0014] Preferably, the axial motion structure comprises a composite electric linear transmission device;

[0015] The composite electric linear transmission device is connected to the lifting support platform, and the composite electric linear transmission device can drive the lifting support platform to move along the axial direction.

[0016] Preferably, the circumferential motion structure includes a servo motor and a processing module protective shell; the processing module protective shell is installed on the lifting support platform, the main shaft of the servo motor is connected to the shaft of the processing module protective shell, and the servo motor can drive the processing module protective shell to rotate along the axial direction around the lifting support platform;

[0017] Preferably, the radial motion structure includes a disc feed track, a feed motor, and a disc feed slide; the disc feed track is installed on the circumferential motion structure, the feed motor is fastened to one side of the disc feed track, and the disc feed slide is slidably installed on the other side of the disc feed track, and the feed motor converts the rotational motion of the feed motor into the feed motion of the disc feed slide along the diameter direction of the disc feed track through a transmission mechanism.

[0018] Preferably, it also includes a supporting structure, which is installed in the first shell; the supporting structure is an inflatable shaft structure, and the key bar of the inflatable shaft can extend out of the first shell to support the inner wall of the insulation sleeve.

[0019] Preferably, it further comprises a hydraulic push rod, wherein the hydraulic push rod is connected to the first housing.

[0020] Preferably, it further comprises a water collecting support plate, wherein the water collecting support plate is installed between the first housing and the hydraulic push rod.

[0021] According to a pipeline electric spark removal and repair method provided by the present invention, the pipeline electric spark removal and repair device is used, and the following steps are also included

[0022] S1. Confirm that the working structure on the pipeline EDM demolition and repair equipment is a cutting and grinding component;

[0023] S2. Place the pipeline EDM removal and repair equipment inside the thermal insulation sleeve, and position the cutting and grinding composite quick-release electrode to the processing station through the composite electric linear transmission device and the feed motor;

[0024] S3. The electrode push rod drives the telescopic electrode block on the cutting and grinding composite quick-release electrode to move to the outermost end, performs low-voltage edge contact on the lower surface of the telescopic electrode block to obtain the initial processing position, and then removes the material of the upper end of the insulation sleeve.

[0025] S4, the electrode push rod drives the telescopic electrode block on the cutting and grinding composite quick-release electrode to move to the innermost end;

[0026] S5: The cutting and grinding composite quick-release electrode is moved to the pipe segment cutting position through the composite electric linear transmission device and the feed motor. The initial processing position is obtained by low-voltage edge contact on the circumferential fan-shaped side of the cutting and grinding composite quick-release electrode. The straight pipe of the insulation sleeve is divided into two sections by electric spark rotary grinding. Then this step is repeated to cut the remaining part of the pipe into several pieces and drag it away from the original position to take out the cut pipe.

[0027] S6: Remove the pipeline electric spark removal and repair equipment from the CRDM tube holder, remove the cutting and grinding assembly, install the grinding quick-release repair electrode on the electrode holder, and place the grinding quick-release repair electrode back into the CRDM tube holder through the feed composite electric linear transmission device and the feed motor, and position the grinding quick-release repair electrode to the specified position.

[0028] S7: The special-shaped grinding surface of the quick-release repair electrode is ground to the edge, and the worn inner wall of the CRDM tube seat is polished and repaired through a low-energy electric spark rotary grinding process, axial rotation and radial micro-feeding through a composite electric linear transmission device and feed motor, laying the foundation for the subsequent installation of a new insulation sleeve.

[0029] Preferably, in step S3, removing the material of the upper end of the thermal insulation sleeve comprises the following steps:

[0030] S3.1. Driven by the composite electric linear drive, the tube is fed downward in the axial direction and subjected to electric spark rotary grinding to completely remove the material from the upper end of the thermal insulation sleeve until the processing is completed;

[0031] Preferably, in step S3, removing the material from the upper end of the thermal insulation sleeve comprises the following steps:

[0032] S3.1. The electrode push rod drives the telescopic electrode block on the cutting and grinding composite quick-release electrode to its outermost end. A low-voltage edge contact is performed on the lower surface of the telescopic electrode block to obtain the initial machining position. The telescopic electrode block is driven axially downward by the composite electric linear drive device. The cutting and grinding assembly performs electric spark forming machining to cut a groove on the upper end of the thermal insulation sleeve. After cutting a groove, the electrode returns to the initial position and is driven by the servo motor to rotate an angle to cut the next groove.

[0033] S3.2. After the last groove is cut, the servo motor drives the side of the telescopic electrode block to perform low-pressure edge contact, and the cutting and grinding assembly performs electrospark forming processing. The upper end of the insulation sleeve and the straight pipe are separated along the circumferential rotation feed, and the upper end of the insulation sleeve is divided into several removable fragments. Compared with the existing technology, the present invention has the following advantages:

[0034] 1. The present invention utilizes a cutting and grinding assembly and a grinding quick-release repair electrode to solve the difficulties in removing and cutting the thermal insulation sleeve and repairing the inner wall of the CRDM tube seat. It also avoids structural damage to the CRDM tube seat caused by conventional cutting methods.

[0035] 2. The present invention facilitates the replacement of electrodes, improves work efficiency, reduces the complexity of device operation and maintenance, and enhances the reliability of device use through the detachable and quick-release design of the quick-release electrode holder, the grinding quick-release repair electrode, and the cutting and grinding components.

[0036] 3. The present invention uses the design of the supporting structure to keep the pipeline EDM removal and repair equipment and the insulation sleeve relatively fixed, avoiding the shaking of the slender pipeline during processing, causing over-processing and damage to other parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0038] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 It is a partial exploded schematic diagram of the internal structure of the present invention;

[0040] Figure 3 This is a schematic diagram of step S2 of the pipeline electric spark removal and repair method of the present invention;

[0041] Figure 4 Schematic diagram of step S3.1 of strategy A of the pipeline electric spark demolition and repair method of the present invention

[0042] Figure 5Schematic diagram of step S4 of the pipeline electric spark removal and repair method of the present invention

[0043] Figure 6 Schematic diagram of step S5 of the pipeline electric spark removal and repair method of the present invention

[0044] Figure 7 Schematic diagram of step S6 of the pipeline electric spark removal and repair method of the present invention

[0045] Figure 8 Schematic diagram of step S7 of the pipeline electric spark removal and repair method of the present invention

[0046] Figure 9 Schematic diagram of step S3.1 of strategy B of the pipeline electric spark demolition and repair method of the present invention

[0047] Figure 10 Schematic diagram of step S3.2 of strategy B of the pipeline electric spark demolition and repair method of the present invention

[0048] The figure shows:

[0049] DETAILED DESCRIPTION

[0050] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0051] The present invention provides a pipeline electric spark removal and repair device, which is mainly used in narrow and long pipelines, and the present invention mainly works and is used inside narrow and long pipelines. Figure 1 Figure 2 As shown, the pipeline electric spark removal and repair equipment includes a radial motion structure, a circumferential motion structure, an axial motion structure, a quick-release connection structure, a working structure, a lifting support platform 5, a first shell 3, a second shell 4 and a top support structure 26, a hydraulic push rod 1, and a water collection support plate 2;

[0052] The axial motion structure is connected to the lifting support platform 5, the circumferential motion structure is installed on the lifting support platform 5, the radial motion structure is installed on the circumferential motion structure, the quick-release connection structure is installed on the radial motion structure, and the working structure is detachably installed on the quick-release connection structure;

[0053] The axial motion structure can drive the lifting support platform 5 to drive the circumferential motion structure to move axially, the circumferential motion structure can drive the radial motion structure to rotate around the axial direction of the circumferential motion structure, and the radial motion structure can drive the quick-release connection structure to make the working structure move radially along the radial motion structure;

[0054] The quick-release connection structure includes a working platform 20 and a quick-release electrode holder 8. The working platform 20 is mounted on the radial motion structure, the quick-release electrode holder 8 is mounted on the working platform 20, and the working structure is detachably mounted on the quick-release electrode holder 8.

[0055] like Figure 2 and Figure 8 As shown, the working structure includes a cutting and grinding assembly and a grinding quick-release repair electrode 25; the cutting and grinding assembly is used to grind away the material of the upper end of the insulation sleeve 10 and cut the insulation sleeve 10; the grinding quick-release repair electrode 25 is used to polish and repair the inner wall of the CRDM tube seat 24 that is worn.

[0056] like Figure 2 As shown, the cutting and grinding assembly includes a cutting and grinding composite quick-release electrode 9, an electrode push rod mounting plate 22, and a telescopic electrode block 23; the cutting and grinding composite quick-release electrode 9 is detachably mounted on the quick-release electrode holder 8, the electrode push rod mounting plate 22 and the telescopic electrode block 23 are mounted on the cutting and grinding composite quick-release electrode 9, the electrode push rod 21 is mounted on the electrode push rod mounting plate 22, and the electrode push rod 21 is connected to the telescopic electrode block 23, and can drive the telescopic electrode block 23 to move; the cutting and grinding composite quick-release electrode 9 is a composite electrode for electric spark grinding and electric spark forming cutting, and the electrode block used for electric spark forming cutting, namely the telescopic electrode block 23, is telescopic, and the telescopic electrode block and the main body of the composite electrode have matching sliding grooves. At the same time, the electrode push rod 21 is used to control the movement of the electrode along the track, solving the problem that the space inside the pipe is too small to process the upper end of the thermal insulation sleeve. In a preferred embodiment, the cutting and grinding composite quick-release electrode 9 also has an electrode penetration detection function, and the electrode penetration detection function determines whether it is penetrated by voltage and current signals.

[0057] The grinding quick-release repair electrode 25 is removably mounted on the quick-release electrode holder 8. This electrode is a profiled electrode that repairs the worn inner wall of the CRDM tube holder 24 through micro-feed electric spark profile grinding. Only one of the grinding quick-release repair electrode 25 and the cutting-grinding composite quick-release electrode 9 can be installed on the quick-release electrode holder 8 at a time. The operator can select whether to install the grinding quick-release repair electrode 25 or the cutting-grinding composite quick-release electrode 9 on the quick-release electrode holder 8 based on actual needs.

[0058] In a preferred embodiment, the cutting and grinding assembly and the grinding quick-release repair electrode 25 are both designed as plug-in quick-release structures, which facilitates the rapid replacement of electrodes in mechanical equipment. The cutting and grinding composite quick-release electrode 9 and the grinding quick-release repair electrode 25 are both graphite (or copper) electrodes. The size of the cutting and grinding composite quick-release electrode 9 and the grinding quick-release repair electrode 25 is determined by factors such as pipeline size, pipeline material, and electrode discharge. The graphite (or copper) electrode is subjected to wire cutting and milling processes to be processed into the required size. The processing polarity of electric spark grinding and electric spark forming cutting is positive. Figure 1 、 Figure 2 As shown, the axial motion structure is installed in the first shell 3, the second shell 4 is sleeved on the outside of the lifting support platform 5, and the first shell 3 and the second shell 4 are fastened together;

[0059] The axial motion structure includes a composite electric linear transmission device 11, the motor shaft of which does not rotate; the axial motion structure is responsible for the movement of the pipeline electric spark removal and repair equipment along the axial direction.

[0060] The composite electric linear transmission device 11 is connected to the lifting support platform 5. Preferably, the axial motion structure further includes a lifting support platform coupling 12. The composite electric linear transmission device 11 is connected to the lifting support platform 5 through the lifting support platform coupling 12. The composite electric linear transmission device 11 can drive the lifting support platform 5 to move axially.

[0061] The circumferential motion structure is responsible for the circumferential rotation of the pipeline EDM demolition and repair equipment. Figure 1 、 Figure 2 As shown, the circumferential motion structure includes a servo motor 6 and a processing module protective shell 7; the processing module protective shell 7 is installed on the lifting support platform 5 and can move with the axial movement of the lifting support platform 5. The servo motor 6 is installed on the lifting support platform 5, and the main shaft of the servo motor 6 is connected to the shaft of the processing module protective shell 7. The servo motor 6 can drive the processing module protective shell 7 to rotate around the axial direction of the lifting support platform 5. In a preferred example, the pipeline electric spark removal and repair equipment also includes a working platform coupling 13 and a bearing 14. The main shaft of the servo motor 6 is connected to the shaft of the processing module protective shell 7 through the working platform coupling 13 to realize the rotational movement of the processing module protective shell 7; the bearing 14 is installed on the lifting support platform 5, and the shaft of the processing module protective shell 7 passes through the inner ring of the bearing 14 and is connected to the working platform coupling 13. The bearing 14 is used to reduce wear and resistance and increase support stiffness.

[0062] like Figure 1 、 Figure 2As shown, the radial motion structure includes a disc feed track 16, a feed motor 15, and a disc feed slide 17; the working platform 20 is mounted on the disc feed slide 17, and the disc feed track 16 is mounted on the circumferential motion structure. Specifically, the disc feed track 16 is mounted on one end of the processing module protective shell 7. The feed motor 15 is firmly mounted on one side of the disc feed track 16, and the feed motor 15 is hidden in the processing module protective shell 7, and the disc feed slide 17 is slidably mounted on the other side of the disc feed track 16. The disc feed slide 17 is slidably mounted on the disc feed track 16, and the feed motor 15 converts the rotational motion of the feed motor 15 into the feeding motion of the disc feed slide 17 along the diameter direction of the disc feed track 16 through a transmission mechanism; that is, the radial motion of the working platform 20 mounted on the disc feed slide 17. In a preferred embodiment, the transmission mechanism includes a meshing rack 18 and a gear 19; the rack 18 is mounted on the disc feed slide 17, and the gear 19 is mounted on the output shaft of the feed motor 15. The radial motion structure is responsible for the radial feeding of the pipeline EDM demolition and repair equipment.

[0063] like Figure 1 、 Figure 2 As shown, the supporting structure 26 is installed in the first shell 3; the supporting structure 26 is a pneumatic shaft structure, and the key bar of the pneumatic shaft can extend out of the first shell 3 to support the inner wall of the thermal insulation sleeve 10. Specifically, the operator can control the supporting structure 26 to extend the key bar of the pneumatic shaft structure out of the first shell 3 to support the inner wall of the thermal insulation sleeve 10 after moving to the specified position, so that the pipeline electric spark removal and repair equipment and the thermal insulation sleeve remain relatively fixed, avoiding the slender pipeline from shaking during processing, causing over-processing and damage to other components. The supporting structure 26 is responsible for fixed support and maintaining relative prohibition with the pipeline, avoiding shaking and movement of the pipeline and falling after the pipeline is cut.

[0064] like Figure 1 As shown, the hydraulic push rod 1 is connected to the first housing 3. Specifically, one end of the hydraulic push rod 1 is connected to the first housing 3, and the other end is connected to the external device. When the length of the CRDM pipe seat 24 is very long and the axial stroke of the composite electric linear transmission device 11 is insufficient, the hydraulic push rod 1 pipeline electric spark removal and repair equipment can achieve contactless movement in the insulation sleeve 10 under the action of the hydraulic push rod 1. It is worth noting that the insulation sleeve 10 is only a part of the pipeline in the main working area. Figure 1 As shown, the water collecting support plate 2 is installed between the first housing 3 and the hydraulic push rod 1 .

[0065] In a preferred embodiment, the pipeline EDM removal and repair equipment is mounted on a specific mobile device, comprising an omnidirectional AGV and a multi-stage folding lift. The omnidirectional AGV carries the entire equipment, moving and positioning it on the ground, while the multi-stage folding lift delivers the equipment to a designated location within the pipeline. The equipment is mounted on a workbench on the multi-stage folding lift, enabling contactless lifting to its working position.

[0066] like Figures 3 to 10 As shown, the present invention also provides a pipeline electric spark demolition and repair device. It is worth noting that the application scenario of the present invention is the same as the application scenario of the background technology, which is as follows: the thermal insulation sleeve 10 has a head 110 and a straight pipe portion 111. The length of the straight pipe portion 111 is very long, preferably 1.7 meters. The length of the CRDM pipe seat 24 is also very long. The thermal insulation sleeve 10 is installed as a whole in the CRDM pipe seat 24. The end of the CRDM pipe seat 24 is fixedly connected to the wall of the nuclear reactor pressure vessel. Figures 3 to 10 In each step diagram, the dashed line without arrows is the axis of the pipeline electric spark demolition and repair equipment, and the solid line with arrows is the actual movement direction.

[0067] The pipeline electric spark removal and repair method further includes the following steps:

[0068] S1. Confirm that the working structure on the pipeline EDM demolition and repair equipment is a cutting and grinding component;

[0069] S2, such as Figure 3 As shown, the pipeline electric spark removal and repair equipment is placed inside the thermal insulation sleeve 10, and the cutting and grinding composite quick-release electrode 9 is positioned to the processing station through the composite electric linear transmission device 11 and the feed motor 15; the processing station is in the head 110.

[0070] S3: The electrode push rod 21 drives the telescopic electrode block 23 on the cutting and grinding composite quick-release electrode 9 to move to the outermost end. The lower surface of the telescopic electrode block 23 is subjected to low-voltage edge contact to obtain the initial processing position, and then the material at the upper end of the thermal insulation sleeve 10 is removed. Specifically, the material in the head 110 is removed.

[0071] S4, such as Figure 5 As shown, the electrode push rod 21 drives the telescopic electrode block 23 on the cutting and grinding composite quick-release electrode 9 to move to the innermost end;

[0072] S5: If Figure 6As shown, the composite electric linear drive 11 and feed motor 15 are used to move the cutting and grinding composite quick-release electrode 9 to the pipe segment cutting position, which is located at the straight pipe portion 111. The initial machining position is obtained by performing low-voltage edge contact on the circumferential sector side of the cutting and grinding composite quick-release electrode 9. Then, electric spark rotary grinding is performed to divide the straight pipe portion 111 of the insulating sleeve 10 into two sections. This step is then repeated to cut the remaining portion of the straight pipe portion 111 into several pieces, which are then dragged away from the original position to remove the cut insulating sleeve 10. Preferably, the process for removing the thermal insulation sleeve 10 is as follows: After the thermal insulation sleeve 10 is cut, specifically, the straight pipe portion 111 after the cut is still held stationary relative to the pipe EDM repair and demolition equipment by the support structure 26. At this point, the EDM repair and demolition equipment is removed from under the CRDM tube holder 24 by gravity and manpower. Simultaneously, the thermal insulation sleeve 10 and the EDM repair and demolition equipment are removed from the CRDM tube holder. The significance of segmented cutting in this step is that, generally, the straight pipe portion 111 of the thermal insulation sleeve 10 is very long, making it difficult to remove. However, cutting the long pipe into several shorter pieces facilitates removal.

[0073] S6: As Figure 7 As shown, the pipeline electric spark removal and repair equipment is withdrawn from the CRDM tube seat 24, and the cutting and grinding assembly is removed. Preferably, the mounting pin on the quick-release electrode seat 8 is removed by external mechanical equipment. The grinding quick-release repair electrode 25 is installed on the quick-release electrode seat 8. Preferably, the forked mounting groove on the grinding quick-release repair electrode 25 is aligned with the mounting groove on the quick-release electrode seat 8 and then the mounting pin is installed to fix it. Then, the grinding quick-release repair electrode 25 is placed into the CRDM tube seat 24 again by feeding the composite electric linear transmission device 11 and the feed motor 15, and the grinding quick-release repair electrode 25 is positioned to the designated position. Specifically, the designated position CRDM tube seat 24 is a relatively spacious position, that is, the position that was damaged in S3 and needs to be repaired.

[0074] S7: As Figure 8 As shown, the special-shaped grinding surface of the quick-release repair electrode 25 is ground to the edge, and the worn inner wall of the tube seat is polished and repaired through a low-energy electric spark rotary grinding process, axial rotation and radial micro-feeding are performed by the composite electric linear transmission device 11 and the feed motor 15, laying the foundation for the subsequent installation of a new insulation sleeve.

[0075] In the pipeline electric spark removal and repair method, in step S3, there are two different strategies for removing the material of the upper end of the thermal insulation sleeve 10. Strategy A includes the following steps: Figure 4As shown, S3.1, driven by the composite electric linear transmission device 11, the heat insulating sleeve 10 is fed downward along the axial direction and subjected to electric spark rotary grinding to completely remove the material of the upper end thereof until the processing is completed; the heat insulating sleeve 10 is located inside the pipe.

[0076] Strategy B includes the following steps: Figure 9 、 Figure 10 As shown, S3.1, the electrode push rod 21 drives the telescopic electrode block 23 on the cutting and grinding composite quick-release electrode 9 to feed and move to the outermost end, and a low-voltage edge contact is performed through the lower surface of the telescopic electrode block to obtain the initial processing position, and the telescopic electrode block 23 is driven axially downward by the composite electric linear transmission device 11, and electrospark forming processing is performed through the cutting and grinding assembly to cut a groove on the upper end of the insulation sleeve 10. After cutting a groove, it returns to the initial position and is driven by the servo motor 6 to rotate an angle to cut the next groove; S3.2, after cutting the last groove, a low-voltage edge contact is performed through the side of the telescopic electrode block 23 under the drive of the servo motor 6, and electrospark forming processing is performed through the cutting and grinding assembly. The upper end of the insulation sleeve 10 and the straight pipe are divided and separated along the circumferential rotation feed, and the upper end of the insulation sleeve 10 is divided into several removable fragments.

[0077] It is worth noting that the operator controls the different discharge amounts on the cutting and grinding composite quick-release electrode 9 according to the different discharge energies required for removing the material of the thermal insulation sleeve 10 and cutting the straight pipe portion 111, so as to achieve the function of the cutting and grinding composite quick-release electrode 9 being used for both removing materials and cutting pipes. Generally speaking, in the process of removing the material of the thermal insulation sleeve 10, the discharge energy required for the cutting and grinding composite quick-release electrode 9 is less than the discharge energy required for cutting the pipe.

[0078] In a preferred embodiment, whether removing material, cutting pipes, or repairing pipes, a flowing working fluid, deionized water, can be introduced through an external conduit. This working fluid, at a constant pressure, is directed to the machining interface via an external pipe to flush debris generated by the EDM process. The wastewater, laden with debris, flows along the wall and ultimately converges into the water collection support disc 2 on the mobile positioning composite mechanism. It is worth noting that the feed motor 15 is mounted on the disc feed track 16 and concealed within the machining module protective housing 7 precisely to prevent it from being affected by the working fluid.

[0079] The inventors discovered that electrospark machining is a non-contact machining method without macroscopic forces. At the same time, it can determine whether the CRDM tube seat has been penetrated by the discharge signal of the electrode penetration detector, thereby avoiding structural damage to the CRDM tube seat. It is a relatively reliable method. However, electrospark machining will still cause a certain degree of wear on the inner wall of the CRDM tube seat. Therefore, after removing the thermal insulation sleeve 10 in the CRDM tube seat, the inner wall of the CRDM tube seat still needs to be repaired. To this end, the present invention proposes a pipeline electrospark removal and repair device, which mainly uses a cutting and grinding component or a grinding quick-release repair electrode 25 to solve the problem of removing the thermal insulation sleeve 10 and repairing the worn part of the CRDM tube seat. The pipeline electrospark removal and repair method provided by the present invention adopts two strategies to remove the material of the upper end of the thermal insulation sleeve 10. Strategy 1: Using a telescopic electrode, the upper end is completely removed by grinding from top to bottom using a rotary EDM process. Strategy 2: Using a telescopic electrode, a cutting and grinding assembly is used to perform a die-spark EDM process, creating several vertical grooves in the bowl-shaped upper end of the insulation sleeve. The upper end is then cut into several fragments using a die-spark EDM process using the telescopic electrode and removed. After the destructive removal of the upper end material, the separated straight pipe is selectively cut into sections. After cutting, the separated straight pipe section 111 is removed. After the insulation sleeve is removed, the grinding quick-release repair electrode is replaced. Preferably, the grinding quick-release repair electrode can be remotely replaced using an external manipulator or other device. The electrode is moved to the appropriate position to reduce the overall radial dimension and enter the pipe. The damaged inner wall surface of the CRDM pipe socket is then repaired using rotary EDM. The present invention uses a quick-release, composite design to achieve damage-free insulation sleeve removal and pipe socket inner wall repair after a single positioning and two pipe entries. The present invention solves the problem of removing the thermal insulation sleeve in a narrow pipeline without damaging the CRDM tube seat, and quickly replaces the electrode through a quick-release design, while achieving the tasks of removing the thermal insulation sleeve and quickly repairing the inner wall of the CRDM tube seat.

[0080] This invention comprehensively addresses the existing challenges of removing the insulation sleeves in nuclear reactor pressure vessels and repairing the inner wall of the CRDM tube socket. By utilizing non-contact EDM and using electrical signals to determine contact and penetration, it effectively addresses the difficulty of segmented removal of vertically suspended, non-fixed pipes with large ends and a narrow center. This effectively prevents damage to the inner wall of the CRDM tube socket caused by over-machining. Furthermore, the design of a composite quick-release electrode facilitates electrode replacement and improves work efficiency.

[0081] The present invention has significant improvements: after the equipment is positioned at the designated working position, the pipe can be fixed by the supporting structure 26, so as to avoid the shaking of the slender pipe during processing and the damage to the equipment and other components caused by the pipe falling after the pipe is cut. The axial, circumferential and radial movements can be respectively achieved through the composite electric linear transmission device 11, the servo motor 6 and the feed motor 15, thereby meeting the requirements of the motion trajectory of the electric spark machining. The present invention can also realize the rapid replacement of electrodes through the quick-release design of the plug-in grooves on the quick-release electrode holder 8, the cutting and grinding composite quick-release electrode 9 and the grinding quick-release repair electrode 25, and realize the segmented removal of the thermal insulation sleeve and the repair of the inner wall of the CRDM pipe holder by using the cutting and grinding composite quick-release electrode 9 and the grinding quick-release repair electrode 25.

[0082] Compared with the prior art, the performance indicators of the present invention are improved in that: the characteristics of electric spark grinding and electric spark forming are comprehensively utilized, and the characteristics of whether there is contact and penetration can be used to accurately control the processing volume. By using the new composite electrode designed by the present invention, the problem of difficult segmented dismantling of vertically suspended, non-fixed pipes with large ends and a slender middle is solved, and electric spark machining is realized in a small space, avoiding damage to the inner wall surface of the CRDM tube seat due to over-machining. After the insulation sleeve is removed, the inner wall surface of the CRDM tube seat is repaired by electric spark profiling grinding. In addition, a quick-release structure of the electrode is designed to make electrode replacement more convenient and quick, save auxiliary time, and improve processing efficiency and processing accuracy to a certain extent, while reducing the probability of damage to other non-currently processed parts.

[0083] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0084] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A pipeline electric spark demolition and repair equipment, characterized in that: It comprises a radial motion structure, a circumferential motion structure, an axial motion structure, a quick-release connection structure, a working structure, a lifting support platform (5), a first shell (3), and a second shell (4); The axial motion structure is connected to the lifting support platform (5), the circumferential motion structure is mounted on the lifting support platform (5), the radial motion structure is mounted on the circumferential motion structure, the quick-release connection structure is mounted on the radial motion structure, and the working structure is detachably mounted on the quick-release connection structure; The axial motion structure can drive the lifting support platform (5) to drive the circumferential motion structure to move axially, the circumferential motion structure can drive the radial motion structure to rotate around the axial direction of the circumferential motion structure, and the radial motion structure can drive the quick-release connection structure to cause the working structure to move radially along the radial motion structure; The quick-release connection structure comprises a working platform (20) and a quick-release electrode seat (8); the working platform (20) is mounted on the radial motion structure, and the quick-release electrode seat (8) is mounted on the working platform (20); the working structure is detachably mounted on the quick-release electrode seat (8); The working structure includes a cutting and grinding assembly and a grinding and quick-release repair electrode (25); the cutting and grinding assembly is used to remove material from the upper end of the thermal insulation sleeve (10) and cut the thermal insulation sleeve (10); the grinding and quick-release repair electrode (25) is used to polish and repair the inner wall of the CRDM tube seat (24) that is worn; The cutting and grinding assembly comprises a cutting and grinding composite quick-detachable electrode (9), an electrode push rod mounting plate (22), and a telescopic electrode block (23); the cutting and grinding composite quick-detachable electrode (9) is detachably mounted on the quick-detachable electrode holder (8), the electrode push rod mounting plate (22) and the telescopic electrode block (23) are mounted on the cutting and grinding composite quick-detachable electrode (9), the electrode push rod (21) is mounted on the electrode push rod mounting plate (22), and the electrode push rod (21) is connected to the telescopic electrode block (23) and can drive the telescopic electrode block (23) to move; The grinding quick-release repair electrode (25) is detachably mounted on the quick-release electrode holder (8); The axial motion structure is installed in the first shell (3), the second shell (4) is sleeved on the outside of the lifting support platform (5), and the first shell (3) and the second shell (4) are tightly connected; Only one of the grinding quick-release repair electrode (25) and the cutting and grinding composite quick-release electrode (9) is installed on the quick-release electrode seat (8) at the same time.

2. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: The axial motion structure includes a composite electric linear transmission device (11); The composite electric linear transmission device (11) is connected to the lifting support platform (5), and the composite electric linear transmission device (11) can drive the lifting support platform (5) to move axially.

3. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: The circumferential motion structure includes a servo motor (6) and a processing module protective shell (7); the processing module protective shell (7) is installed on the lifting support platform (5), the main shaft of the servo motor (6) is connected to the shaft of the processing module protective shell (7), and the servo motor (6) can drive the processing module protective shell (7) to rotate around the axial direction of the lifting support platform (5).

4. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: The radial motion structure comprises a disc feed track (16), a feed motor (15), and a disc feed slide (17); the disc feed track (16) is mounted on the circumferential motion structure, the feed motor (15) is fixedly mounted on one side of the disc feed track (16), and the disc feed slide (17) is slidably mounted on the other side of the disc feed track (16); the feed motor (15) converts the rotational motion of the feed motor (15) into a feeding motion of the disc feed slide (17) along the diameter direction of the disc feed track (16) through a transmission mechanism.

5. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: It also includes a supporting structure (26), which is installed in the first shell (3); the supporting structure (26) is an air shaft structure, and the key bar of the air shaft structure can extend out of the first shell (3) to support the inner wall of the thermal insulation sleeve (10).

6. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: It also includes a hydraulic push rod (1), which is connected to the first housing (3).

7. The pipeline electric spark demolition and repair equipment according to claim 1 is characterized in that: It also includes a water collection support plate (2), which is installed between the first housing (3) and the hydraulic push rod (1).

8. A pipeline electric spark removal and repair method, characterized in that: The pipeline electric spark demolition and repair equipment according to any one of claims 1 to 7 further comprises the following steps: S1. Confirm that the working structure on the pipeline EDM demolition and repair equipment is a cutting and grinding component; S2, placing the pipeline electric spark removal and repair equipment into the interior of the thermal insulation sleeve (10), and positioning the cutting and grinding composite quick-release electrode (9) to the processing station through the composite electric linear transmission device (11) and the feed motor (15); S3, the electrode push rod (21) drives the telescopic electrode block (23) on the cutting and grinding composite quick-release electrode (9) to feed and move to the outermost end, performs low-voltage edge contact on the lower surface of the telescopic electrode block (23) to obtain the initial processing position, and then removes the material of the upper end of the thermal insulation sleeve (10); S4, the electrode push rod (21) drives the telescopic electrode block (23) on the cutting and grinding composite quick-release electrode (9) to move to the innermost end; S5, moving the cutting and grinding composite quick-release electrode (9) to the pipe segment cutting position through the composite electric linear transmission device (11) and the feed motor (15), obtaining the processing initial position by performing low-voltage edge contact on the circumferential fan-shaped side surface of the cutting and grinding composite quick-release electrode (9), performing electric spark rotary grinding to divide the straight pipe of the insulation sleeve (10) into two sections, and then repeating this step to cut the remaining part of the pipe into several pieces and drag it away from the original position, and take out the cut pipe; S6, withdrawing the pipeline electric spark removal and repair equipment from the CRDM tube holder (24), removing the cutting and grinding assembly, installing the grinding quick-release repair electrode (25) on the electrode holder (8), and placing the grinding quick-release repair electrode (25) back into the CRDM tube holder (24) through the feed composite electric linear transmission device (11) and the feed motor (15), and positioning the grinding quick-release repair electrode (25) to a designated position; S7. The special-shaped grinding surface of the quick-release repair electrode (25) is ground to the edge, and the worn inner wall of the CRDM tube seat (24) is polished and repaired by a low-energy electric spark rotary grinding process, axial rotation and radial micro-feeding are performed by a composite electric linear transmission device (11) and a feed motor (15), laying the foundation for the subsequent installation of a new insulation sleeve.

9. The pipeline electric spark removal and repair method according to claim 8, characterized in that: In step S3, the removal of the material from the upper end of the thermal insulation sleeve (10) comprises the following steps: S3.

1. Driven by the composite electric linear transmission device (11), the device is fed downwardly in the axial direction to perform electric spark rotary grinding to completely remove the material of the upper end of the thermal insulation sleeve (10) until the processing is completed.

10. The pipeline electric spark removal and repair method according to claim 8, characterized in that: In step S3, the removal of the material from the upper end of the thermal insulation sleeve (10) comprises the following steps: S3.1, the electrode push rod (21) drives the telescopic electrode block (23) on the cutting and grinding composite quick-release electrode (9) to feed and move to the outermost end, and obtains the initial processing position by performing low-voltage edge contact on the lower surface of the telescopic electrode block. The telescopic electrode block (23) is driven axially downward by the composite electric linear transmission device (11), and the cutting and grinding assembly is used to perform electric spark forming processing to cut a groove on the upper end of the thermal insulation sleeve (10). After cutting a groove, the electrode returns to the initial position and is rotated by an angle under the drive of the servo motor (6) to cut the next groove. S3.

2. After the last groove is cut, the servo motor (6) drives the side of the telescopic electrode block (23) to perform low-pressure edge contact, and the cutting and grinding assembly performs electrospark forming processing, and the upper end of the thermal insulation sleeve (10) and the straight pipe are divided and separated along the circumferential rotation feed, and the upper end of the thermal insulation sleeve (10) is divided into a plurality of removable fragments.

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