Guiding device suitable for hoisting reactor large piece of nuclear power station
By designing a guide device suitable for lifting large parts of reactors in nuclear power plants, the problems of extended overhaul time and safety risks caused by frequent replacement of guide devices in the prior art are solved, and the one-time lifting of the "three major parts" of nuclear power plants is realized, the maintenance process is optimized and the irradiation dose is reduced.
Patent Information
- Application Number
- CN202421630511.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-07-10
AI Technical Summary
During the overhaul of material replacement in nuclear power plants, existing guide devices need to be replaced frequently, resulting in repeated flushing, drainage, cleaning and hoisting operations of the pool, extending the overhaul time and increasing the irradiation dose of personnel and industrial safety risks.
A guide device suitable for lifting large parts of reactors in nuclear power plants is designed. The device includes guide columns, long rod spreaders and guide column key blocks. It can be installed in one go, achieving precise guidance on the removal and installation process of the pressure vessel top cover, upper stack inner members and lower stack inner members, avoiding flushing and drainage and other auxiliary work.
This guide device realizes one-time lifting of the "three major parts" of the nuclear power plant, shortens the time-consuming on-site overhaul of nuclear power, reduces the irradiation dose of operators, optimizes the maintenance process, and reduces the risks of industrial safety operation.
Smart Images
Figure CN222860991U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of nuclear power maintenance, in particular to a guiding device suitable for hoisting large reactor components in a nuclear power plant. Background Art
[0002] During the refueling overhaul of a nuclear power plant, the lifting of the reactor pressure vessel top cover, upper reactor internals and lower reactor internals are the most important equipment lifting operations in the nuclear island, and are known as the "three major pieces" lifting of the nuclear island. They are the key path for the overhaul of the nuclear island of a nuclear power plant.
[0003] During the first overhaul, ten-year overhaul or other special circumstances of a nuclear power unit, it is necessary to complete the disassembly and installation of the pressure vessel top cover, upper reactor internals and lower reactor internals at the same time. At present, two types of guide devices are used during the lifting of the three major parts. The first type is stored in the nuclear island refueling pool, which is a short guide device used for the disassembly and installation of the pressure vessel top cover and upper reactor internals; the other type is stored in the maintenance workshop and is temporarily transported into the nuclear island for installation, and is a long guide device used for the disassembly and installation of the lower reactor internals. If the lower reactor internals need to be disassembled and installed, the lower reactor internals hoisting guide device must be transported into the nuclear island after unloading is completed, and the pool must be drained and cleaned at the same time, the short guide device must be removed, the long guide device must be reinstalled, and the water level must be raised again to disassemble the lower reactor internals. After the upper and lower reactor internals are reinstalled, the short guide device for the upper reactor internals and pressure vessel top cover hoisting must be replaced after the pool is drained and cleaned again. Repeated flushing and drainage, pool cleaning and hoisting will extend the main line overhaul time, while increasing the radiation dose of personnel and the industrial safety risks of hoisting operations. Utility Model Content
[0004] The utility model aims to provide a guiding device suitable for hoisting large parts of a nuclear power plant reactor, which can realize hoisting the "three major parts" of the nuclear island using the same set of tools and shorten the time consumed for on-site overhaul of the nuclear power plant.
[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0006] A guide device suitable for lifting large parts of a nuclear power plant reactor comprises a guide column, wherein the guide column has a first connecting part, an intermediate column, and a second connecting part; a long rod hoist is connected above the first connecting part, and the length of the long rod hoist is greater than or equal to 800 mm; a disassembly hole is provided on the intermediate column for installing an operating handle; and a guide column key block is installed on the second connecting part.
[0007] In some embodiments, the bottom of the long rod hanger has an external thread, the first connecting portion has a connecting hole, the connecting hole has an internal thread, and the internal thread is adapted to the external thread.
[0008] In some embodiments, the first connecting portion has a length of 304 mm and a taper of 1.5°.
[0009] In some embodiments, the outer diameter of the intermediate cylinder is 155.4±0.25 mm and the straightness is 0.75 mm.
[0010] In some embodiments, the outer diameter of the second connecting portion is smaller than the outer diameter of the intermediate column, and the second connecting portion is the connecting portion between the guide column and the screw hole of the pressure vessel, which can ensure the verticality of the guide column.
[0011] In some embodiments, the disassembly hole is arranged horizontally and passes through the guide column.
[0012] In some embodiments, the length of the second connecting portion is 216 mm, and the guide column key block is installed by bolts.
[0013] In some embodiments, the guide column key block is a rectangular parallelepiped structure.
[0014] In some embodiments, the guide column key block is a rectangular parallelepiped structure, and the installation position is 175 mm away from the bottom surface of the guide column.
[0015] In some embodiments, the top of the long rod hanger has a circular connecting portion, the middle portion is a long rod structure, and the outer diameter of the long rod structure is not less than 20 mm.
[0016] Compared with the prior art, the guiding device for hoisting large nuclear power plant reactors provided by the utility model has the following beneficial effects:
[0017] The guiding device provided by the utility model can be installed once to realize precise guidance of the removal and installation process of the pressure vessel top cover, upper in-pile components and lower in-pile components, without the need for flushing and drainage and other necessary auxiliary work, effectively reducing the radiation dose of operators and optimizing the maintenance process. A single use can reduce the overhaul critical path by more than 20 hours.
[0018] The utility model utilizes a long-pole hoist for hoisting during disassembly and assembly, and is operated by personnel standing on the core auxiliary bridge, thereby avoiding the need for personnel to perform hooking and unhooking operations by climbing a ladder, thereby reducing the dosage of operators and the risk of industrial safety operations. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solution of the present utility model, the drawings required for the technical description are briefly introduced below.
[0020] Figure 1 A schematic diagram of the structure of a guide device for hoisting large reactor components in a nuclear power plant provided by the utility model;
[0021] Figure 2 A schematic diagram of the installation working condition of the long-pole sling provided by the utility model;
[0022] Figure 3 A schematic diagram of the guide for lifting the top cover of a pressure vessel provided by the utility model;
[0023] Figure 4 A schematic diagram of the lower internals entry / exit guide device provided by the utility model;
[0024] Figure 5 This is a schematic diagram of the lower internals provided by the utility model entering / leaving the pressure vessel.
[0025] Description of reference numerals:
[0026] 1. Long rod lifting fixture, 2. Guide column, 3. Disassembly and assembly hole, 4. Guide column key block, 5. Top cover triangular lifting fixture, 6. Pressure vessel top cover, 7. Pressure vessel, 8. Internal component lifting fixture, 9. Lower internal component, 10. Core auxiliary bridge of refueling pool, 11. Internal component pool, 12. Operating handle. DETAILED DESCRIPTION
[0027] The following is further explained in detail through specific implementation methods.
[0028] like Figure 1 As shown, the utility model provides a guiding device suitable for lifting large parts of a nuclear power plant reactor, comprising a long rod lifting device 1, a guide column 2, a disassembly hole 3, and a guide column key block 4. The guiding device is suitable for lifting and guiding the top cover of a nuclear power plant pressure vessel, upper internal components and lower internal components.
[0029] The long-pole hanger 1 is a long-pole structure as a whole, with a circular ring connection at the top, an external thread connection at the bottom, and a long-pole structure in the middle. The diameter of the long-pole hanger 1 is not less than 20 mm. The main function of the long-pole hanger 1 is to provide lifting for the installation and removal of the guide column 2. The top is connected to the ring hanger, and the bottom is screwed into the top of the guide column 2 through the external thread.
[0030] like Figure 2 As shown, in order to ensure that the operator can operate the lifting device on the core auxiliary bridge 10 of the refueling pool (above the internal component pool 11) to screw in and out the guide column 2, the length of the long rod lifting device 1 should be greater than or equal to 800 mm to achieve the disassembly, assembly and transportation of the guide column 2 between the screw hole of the pressure vessel 7 and the storage rack.
[0031] like Figure 1 As shown, the guide column 2 includes a first connection part, an intermediate column and a second connection part, and these three parts are welded into a whole. The first connection part is the upper connection part, which is used to connect the long rod hanger 1; the second connection part is the lower connection part, which is used to connect the screw hole of the pressure vessel. The guide column 2 is a hollow structure.
[0032] The first connection part has a conical transition section structure with a length of 304 mm and a taper of 1.5°. A connection hole is provided at the top of the first connection part, and an internal thread is provided in the connection hole. The internal thread is adapted to the external thread at the bottom of the long-pole sling 1, so as to threadably connect the long-pole sling 1 and the guide column 2.
[0033] The middle column is a column structure with an outer diameter of 155.4±0.25mm and a straightness of 0.75mm. The middle column is an effective guide section of the entire guide device. A disassembly hole 3 is also provided on the middle column, which is mainly used for the rotation operation when the guide column 2 is disassembled. The disassembly hole 3 is used to connect the operating handle 12.
[0034] The disassembly hole 3 is arranged horizontally (perpendicular to the axis of the guide column 2) and penetrates the guide column 2, so that the operating handle 12 can be inserted into the disassembly hole 3. The disassembly hole 3 is adapted to the operating handle 12, and the diameter of the disassembly hole 3 is 20-34 mm, and the diameter of the operating handle 12 is slightly smaller than the diameter of the disassembly hole 3.
[0035] The second connection part is a precision-machined installation section with a length of 216 mm, and a key block (i.e., guide column key block 4) is installed by bolts, which is mainly used for locking and fixing the guide device and the screw hole of the pressure vessel. The outer diameter of the second connection part is smaller than the outer diameter of the intermediate column, and its outer diameter is 109.95 mm.
[0036] An M20 threaded hole is provided at the bottom of the second connection portion, which is a process hole for processing the guide column and does not affect the use of the guide column.
[0037] The guide column key block 4 is a rectangular parallelepiped structure, and the installation position is 175 mm away from the bottom surface of the guide column.
[0038] like Figures 3 to 5 As shown, the lower internal component 9 is the longest and requires the largest guiding stroke. The shortest length of the guiding device must meet the disassembly and assembly guiding of the lower internal component 9. At the same time, after the installation is completed, the guiding device does not interfere with the ring rail of the triangular hanger above the pressure vessel top cover 6 (i.e., the top cover triangular hanger 5), so that one-time installation can be achieved and the lifting and guiding of the three major components can be met.
[0039] like Figure 3 As shown, the height h1 of the guide column mounting flange of the pressure vessel is 11027mm, the depth h2 of the guide column mounting hole is 216mm, and the height h3 of the ring rail above the pressure vessel top cover 6 is 19930mm. The maximum length of the guide device should not exceed 19930-11027+216=9119mm. When the overall length of the guide device does not exceed 9119mm, it can be installed in the flange hole of the pressure vessel.
[0040] like Figure 4As shown, the distance h4 from the upper surface of the flange of the lower internal component to the radial support at the bottom is 8240.52 mm, the height h5 from the support surface of the flange of the lower internal component in the pressure vessel 7 to the flange surface of the pressure vessel is 292 mm, and the distance h6 from the lower edge of the guide cylinder of the internal component hoist 8 to the upper surface of the flange of the lower internal component is 567 mm. The shortest length h7 of the guide device is not less than 8240.52-292+567+216=8731.52 mm, which can meet the lifting requirements of the lower internal component 9.
[0041] The total length of the guide device is controlled between 8731.52 mm and 9119 mm, which can simultaneously meet the lifting and guiding requirements of the reactor pressure vessel top cover 6, the upper internals and the lower internals 9, thereby ensuring the safety of the lifting.
[0042] The installation process of the guide device provided by the utility model is as follows:
[0043] like Figure 1 As shown, the guide device is mainly composed of a long rod hanger 1, a guide column 2, and a guide column key block 4. The guide column is installed as shown in the attached Figure 2 As shown, install the guide column key block 4 in the matching groove of the guide column 2, insert the operating handle 12 into the disassembly hole 3, use the long rod hanger 1 on the top of the guide device to install the guide device into the screw hole of the pressure vessel, use the operating handle 12 to rotate the guide device to lock the guide device and the screw hole of the pressure vessel to complete the installation of the guide column 2. After the installation is completed, manually remove the long rod hanger 1 on the mobile bridge refueling pool core auxiliary bridge 10, and the installation of the guide device is completed.
[0044] The installation and removal process of the guide device provided by the utility model for the pressure vessel top cover 6 and the upper and lower internal components is as follows:
[0045] Pressure vessel top cover 6 hoisting Figure 3 As shown, during the process of using the ring to lift the pressure vessel top cover, the pressure vessel top cover 6 moves upward along the guide column 2 to lift the pressure vessel top cover 6 away from the pressure vessel 7 or reinstall it.
[0046] The lower internal component 9 is hoisted as shown in Attachment 4. Figure 5 As shown, a ring hoist and a special hoist for in-pile components are used to hoist the in-pile components upward from the pressure vessel 7 along the direction of the guide column 2. During the hoisting process, the guide column 2 provides guidance for the in-pile component hoist 8. During the process of hoisting the upper and lower in-pile components out of the pressure vessel 7, the length of the guide section of the guide column 2 can ensure that the upper and lower in-pile components are moved out of the pressure vessel 7.
[0047] The process flow of the guide device provided by the utility model mainly includes:
[0048] (1) Install three bushings with a depth of 216 mm in the flange of the pressure vessel shell;
[0049] (2) Use the long-pole lifting device 1 to drop the guide device from the storage rack to the top of the pressure vessel top cover 6, pass it through the screw hole of the top cover flange, install the guide device into the screw hole bushing, and rotate and lock it;
[0050] (3) Install the top cover triangular hanger 5 on the pressure vessel top cover 6;
[0051] (4) by using the top cover triangular lifting device 5, the guide device directly lifts the pressure vessel top cover 6 away from the pressure vessel core;
[0052] (5) After the pool is flushed, the upper internals are directly lifted off the pressure vessel 7 by the internals lifting device 8 through the guide device;
[0053] (6) After unloading is completed, the lower internals 9 are directly lifted off the pressure vessel 7 by using the internals lifting device 8 through the guide device;
[0054] (7) After the low water level work is completed, the lower internals 9 are directly hoisted back to the pressure vessel 7 using the internals hoist 8 through the guide device;
[0055] (8) After loading is completed, the upper internals are hoisted back to the pressure vessel 7 using the internals hoist 8 through the guide device;
[0056] (9) After the pool is drained, the pressure vessel top cover 6 is directly hoisted back to the pressure vessel core using the top cover triangular hoist 5 through the guide device;
[0057] (10) Remove the top cover triangular hanger 5;
[0058] (11) Use the long rod sling 1 to connect the guide device and remove the guide device;
[0059] (12) Remove the main screw hole bushing.
[0060] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.
Claims
1. A guiding device suitable for hoisting large parts of a nuclear power plant reactor, characterized in that: The invention comprises a guide column (2), wherein the guide column (2) has a first connection part, an intermediate column body, and a second connection part; a long rod sling (1) is connected to the top of the first connection part; the length of the long rod sling (1) is greater than or equal to 800 mm; a disassembly hole (3) is provided on the intermediate column body for installing an operating handle (12); and a guide column key block (4) is installed on the second connection part.
2. The guiding device for hoisting large nuclear power plant reactors according to claim 1 is characterized in that: The bottom of the long-pole sling (1) has an external thread, the first connecting portion is provided with a connecting hole, the connecting hole is provided with an internal thread, and the internal thread is adapted to the external thread.
3. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The length of the first connecting portion is 304 mm, and the taper is 1.5°.
4. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The outer diameter of the intermediate cylinder is 155.4±0.25 mm, and the straightness is 0.75 mm.
5. The guiding device for hoisting large nuclear power plant reactors according to claim 4 is characterized in that: The outer diameter of the second connecting portion is smaller than the outer diameter of the intermediate cylinder.
6. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The disassembly hole (3) is arranged horizontally and passes through the guide column (2).
7. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The length of the second connecting portion is 216 mm, and the guide column key block (4) is installed by bolts.
8. The guiding device for hoisting large nuclear power plant reactors according to claim 1 or 7, characterized in that: The guide column key block (4) is a rectangular parallelepiped structure.
9. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The installation position of the guide column key block (4) is 175 mm away from the bottom surface of the guide column (2).
10. The guiding device for hoisting large nuclear power plant reactors according to claim 1, characterized in that: The top of the long rod hanger (1) is provided with a circular ring-shaped connecting portion, the middle portion is a long rod structure, and the outer diameter of the long rod structure is greater than or equal to 20 mm.