Simulation experiment device for reactor bottom of nuclear power reactor

Abstract

The invention belongs to the technical field of nuclear industry equipment maintenance, and particularly relates to a nuclear power reactor bottom simulation experiment device which comprises a pressure vessel wall, a plurality of replaceable flux tube assemblies, a plurality of fixed flux tubes and at least one supporting leg. At least one supporting leg is installed at the edge of the bottom end of the pressure vessel wall and used for supporting the pressure vessel wall. The replaceable flux pipe assemblies and the fixed flux pipes penetrate through the wall of the pressure container and are detachably installed on the wall of the pressure container. The top end of each replaceable flux tube assembly is provided with at least one quick release connector. The quick-release connector is used for being externally connected with machining equipment. The simulation experiment device for the reactor bottom of the nuclear power reactor is arranged for an experiment instead of being operated on a reactor site, so that the technical problems that the neutron flux measurement precision is seriously influenced and potential safety hazards of a unit are generated due to the fact that weld joints of existing neutron flux tubes are prone to deformation and cracking are solved.

Description

Technical Field

[0001] This application belongs to the field of nuclear industry equipment maintenance technology, specifically relating to a simulation experimental device for the bottom of a nuclear power reactor. Background Technology

[0002] The neutron flux tube in a nuclear power reactor is a crucial device for measuring neutron flux, essential for controlling the nuclear reaction process and ensuring stable operation. Typically, the neutron flux tube is installed at the bottom of the reactor pressure vessel (i.e., the reactor bottom). To ensure the sealing and stability of the reactor pressure vessel, the connection between the neutron flux tube and the reactor bottom is usually achieved by welding. However, because the weld seam of the neutron flux tube is periodically subjected to high temperatures, high radiation, and cyclic loads in boric acid water, defects such as cracks and porosity left over from the weld production process will amplify. Under cyclic external loads, the neutron flux tube weld seam will deform and crack, severely affecting the accuracy of neutron flux measurement and creating potential safety hazards for the unit. Summary of the Invention

[0003] In view of this, this application provides a simulation experimental device for the bottom of a nuclear power reactor. By setting up this simulation experimental device for the bottom of the nuclear power reactor, instead of operating on-site at the reactor, the technical problem of easy deformation and cracking of the weld of the existing neutron flux tube, which seriously affects the accuracy of neutron flux measurement and creates potential safety hazards for the unit, is solved.

[0004] This application provides a simulation experimental apparatus for the bottom of a nuclear power reactor. The apparatus includes a pressure vessel wall, multiple replaceable flow tube assemblies, multiple fixed flow tubes, and at least one support leg. The at least one support leg is installed at the bottom edge of the pressure vessel wall to provide support. The multiple replaceable flow tube assemblies and the multiple fixed flow tubes all penetrate the pressure vessel wall and are detachably installed therefrom. Each replaceable flow tube assembly has at least one quick-release interface at its top. The quick-release interface is used to connect external processing equipment.

[0005] In one specific embodiment of this application, the pressure vessel wall is provided with a plurality of square grooves corresponding to a plurality of replaceable flow tube assemblies, and the sidewalls of the square grooves are provided with positioning pin holes that match the positioning pins on the replaceable flow tube assemblies. Bolts are built into the bottom of the square grooves.

[0006] In one specific embodiment of this application, the replaceable flow tube assembly includes a replaceable flow tube and a base. The replaceable flow tube is mounted on the base, which is placed in a square groove on the pressure vessel wall and connected to the pressure vessel wall with bolts.

[0007] In one specific embodiment of this application, the replaceable flux tube assembly is designed with a threaded interface and a locating pin groove corresponding to the bottom assembly.

[0008] In one specific embodiment of this application, the top of the replaceable flux tube assembly is provided with a threaded hook.

[0009] In one specific embodiment of this application, the replaceable flux tube assembly employs a shoulder restraint and positioning mechanism.

[0010] In one specific embodiment of this application, multiple replaceable flux tube assemblies are of different sizes. And / or, multiple fixed flux tubes are of different sizes.

[0011] In one specific embodiment of this application, the number of replaceable flow tube assemblies is five. The five replaceable flow tube assemblies include a first replaceable flow tube assembly, a second replaceable flow tube assembly, a third replaceable flow tube assembly, a fourth replaceable flow tube assembly, and a fifth replaceable flow tube assembly. The second, third, fourth, and fifth replaceable flow tube assemblies are arranged side-by-side along the length of the pressure vessel wall. The first and second replaceable flow tube assemblies are arranged side-by-side along the width of the pressure vessel wall.

[0012] In one specific embodiment of this application, the number of fixed flow tubes is four. The four fixed flow tubes include a first fixed flow tube, a second fixed flow tube, a third fixed flow tube, and a fourth fixed flow tube. The first and second fixed flow tubes are arranged side-by-side along the width direction of the pressure vessel wall. The third and fourth fixed flow tubes are arranged side-by-side along the length direction of the pressure vessel wall.

[0013] In one specific embodiment of this application, the pressure vessel wall has a quadrilateral arc structure, and there are four support legs, which are evenly distributed at the four corners of the bottom of the pressure vessel wall.

[0014] The beneficial effects of the technical solution of this application are as follows: experiments are conducted by setting up a simulation experimental device at the bottom of the nuclear power reactor, rather than operating on-site at the reactor. The simulation experimental device at the bottom of the nuclear power reactor is modularly designed (e.g., divided into pressure vessel wall, multiple replaceable flow tube assemblies, multiple fixed flow tubes, and at least one support leg). Furthermore, by setting quick-release interfaces at the top of the replaceable flow tube assemblies and fixed flow tubes, various processing equipment can be connected externally, which is especially suitable for circumferential processing. This shortens reactor maintenance downtime and reduces radiation exposure for operators and economic losses. Attached Figure Description

[0015] Figure 1 The diagram shown is a structural schematic of a simulation experimental device for the bottom of a nuclear power reactor provided in at least one embodiment of this application.

[0016] Figure 2The figure shown is a dimensional diagram of a pressure vessel wall provided in at least one embodiment of this application.

[0017] Figure 3 The figure shown is a dimensional diagram of a replaceable flow tube and its base provided in at least one embodiment of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] At least one embodiment of this application provides a simulation experimental device for the bottom of a nuclear power reactor. This simulation experimental device simulates the bottom of a nuclear power reactor at a 1:1 scale and can simultaneously meet the experimental requirements for various testing and repair techniques of neutron flux tube welds.

[0020] like Figure 1 As shown, the simulation experimental device for the bottom of the nuclear power reactor includes a pressure vessel wall 1, multiple replaceable flow tube assemblies 2, multiple fixed flow tubes 3, and at least one support leg 4. At least one support leg is installed at the bottom edge of the pressure vessel wall to provide support. The multiple replaceable flow tube assemblies 2 and the multiple fixed flow tubes 3 all penetrate the pressure vessel wall 1 and are detachably installed from it. Each fixed flow tube 3 has at least one quick-release interface at its top. The quick-release interface is used to connect external processing equipment.

[0021] It should be noted that the bottom of the pressure vessel wall 1 can adopt a lightweight yet robust frame structure, which ensures overall stability while effectively reducing the overall weight, facilitating handling and installation. The fixed flux tube 3 is a neutron flux tube. The material, manufacturing process, and dimensions of the simulation experimental device at the bottom of the nuclear power reactor are consistent with those of the reactor bottom, and the relevant tests can directly reflect the actual working conditions. The fixed flux tube 3 can directly pass through the circular opening on the pressure vessel wall 1 and be welded to the pressure vessel wall 1. The processing equipment can be laser shock peening equipment, scanning inspection simulation test, etc., and this application embodiment does not specifically limit the processing equipment.

[0022] In this embodiment, the experiment is conducted by setting up a simulation experimental device at the bottom of the nuclear power reactor, rather than operating on-site at the reactor. The simulation experimental device at the bottom of the nuclear power reactor is modularly designed (e.g., divided into a pressure vessel wall 1, multiple replaceable flow tube assemblies 2, multiple fixed flow tubes 3, and at least one support leg 4). By setting quick-release interfaces at the top of the replaceable flow tube assemblies 2 and the fixed flow tubes 3, various processing equipment can be connected, which is especially suitable for circumferential processing. This shortens the reactor maintenance downtime and reduces the radiation levels of operators and economic losses.

[0023] In some embodiments, the simulation experimental device for the bottom of the nuclear power reactor can strictly follow the size ratio and outline of the real reactor bottom to ensure a one-to-one correspondence of all key parts (such as the orientation of the neutron flux tube, the shape of the weld, etc.) to achieve a high-precision simulation effect; it can also use the same or similar materials as the real reactor bottom to simulate its mechanical properties, corrosion resistance and thermal conductivity under actual working conditions.

[0024] In at least one embodiment of this application, the pressure vessel wall 1 is provided with a plurality of square grooves corresponding to a plurality of replaceable flow tube assemblies 2, and the sidewalls of the square grooves are provided with positioning pin holes that match the positioning pins on the replaceable flow tube assemblies 2. A bolt is built into the bottom of the square groove.

[0025] In this embodiment, a square groove is designed on the pressure vessel wall 1. The square design of the groove effectively restricts the rotational movement between components. Simultaneously, a high-strength bolt is built into the bottom of the square groove, facilitating precise alignment during installation and ensuring connection strength. Furthermore, positioning pin holes are added to the sidewalls of the square groove, which cooperate with the positioning pins on the replaceable flow tube assembly 2 to achieve precise positioning and rapid docking, thus improving the adaptability and stability of the pressure vessel wall.

[0026] In at least one embodiment of this application, the replaceable flow tube assembly 2 includes a replaceable flow tube and a base. The replaceable flow tube is mounted on the base, which is placed in a square groove on the pressure vessel wall 1 and connected to the pressure vessel wall with bolts.

[0027] For example, refer to Figure 2 E refers to the width of the base, see reference. Figure 3 D refers to the height of the replaceable flux tube in the simulation experimental device at the bottom of the nuclear power reactor, and F refers to the length of the base.

[0028] In at least one embodiment of this application, the replaceable flux tube assembly 2 is designed with a threaded interface and a locating pin groove corresponding to the stack bottom assembly. This ensures a seamless connection and stable connection between the replaceable flux tube assembly 2 and the stack bottom assembly.

[0029] In at least one embodiment of this application, the top of the replaceable flux tube assembly 2 is provided with a threaded hook. This facilitates lifting and disassembly.

[0030] In at least one embodiment of this application, the replaceable flux tube assembly 2 employs a shoulder restraint and positioning mechanism. This prevents the replaceable flux tube assembly 2 from shifting or loosening during use.

[0031] In the above embodiments, the replaceable flux tube assembly 2 and the stack bottom assembly adopt a precise transition fit design, which ensures both disassembly and tightness and sealing of the connection, making it easy to quickly replace different parts or adjust experimental conditions according to experimental needs.

[0032] In at least one embodiment of this application, the multiple replaceable flow tube assemblies 2 are of different sizes. The multiple fixed flow tubes 3 are of different sizes.

[0033] In at least one embodiment of this application, the number of the plurality of replaceable flux tube assemblies 2 is five. (See reference...) Figure 1 The five replaceable flow tube assemblies 2 include a first replaceable flow tube assembly 201, a second replaceable flow tube assembly 202, a third replaceable flow tube assembly 203, a fourth replaceable flow tube assembly 204, and a fifth replaceable flow tube assembly 205. The second replaceable flow tube assembly 202, the third replaceable flow tube assembly 203, the fourth replaceable flow tube assembly 204, and the fifth replaceable flow tube assembly 205 are arranged side-by-side along the length of the pressure vessel wall 1. The first replaceable flow tube assembly 201 and the second replaceable flow tube assembly 202 are arranged side-by-side along the width of the pressure vessel wall 1.

[0034] In at least one embodiment of this application, the number of the plurality of fixed flux tubes 3 is four. (See reference...) Figure 1 The four fixed flow tubes 3 include a first fixed flow tube 301, a second fixed flow tube 302, a third fixed flow tube 303, and a fourth fixed flow tube 304. The first fixed flow tube 301 and the second fixed flow tube 302 are arranged side by side along the width direction of the pressure vessel wall 1. The third fixed flow tube 303 and the fourth fixed flow tube 304 are arranged side by side along the length direction of the pressure vessel wall 1.

[0035] For example, the dimensions of pressure vessel wall 1 can be as follows: Figure 2 As shown, Figure 2 In the diagram, A refers to the horizontal width of the simulation experimental setup at the bottom of the nuclear power reactor. B refers to the horizontal length of the simulation experimental setup at the bottom of the nuclear power reactor.

[0036] Figure 2In this context, C0 refers to the horizontal distance between the center of the first replaceable flow tube assembly 201 and the shortest side of the pressure vessel wall 1 that is closest to the center in a straight line along the length of the pressure vessel wall 1, and the horizontal distance between the center of the second replaceable flow tube assembly 202 and the shortest side of the pressure vessel wall 1 that is closest to the center in a straight line along the length of the pressure vessel wall 1. C1 refers to the horizontal distance between the center of the second replaceable flow tube assembly 202 and the center of the third replaceable flow tube assembly 203, along the length of the pressure vessel wall 1. C4 refers to the horizontal distance between the center of the fourth replaceable flow tube assembly 204 and the center of the second replaceable flow tube assembly 202, along the length of the pressure vessel wall 1. C5 refers to the horizontal distance between the center of the fifth replaceable flow tube assembly 205 and the center of the second replaceable flow tube assembly 202, along the length of the pressure vessel wall 1; and the horizontal distance between the center of the fourth fixed flow tube 304 and the center of the second replaceable flow tube assembly 202. C7 refers to the horizontal distance between the center of any one of the second replaceable flow tube assembly 202, the third replaceable flow tube assembly 203, the fourth replaceable flow tube assembly 204, and the fifth replaceable flow tube assembly 205, which is closest to the long side of the pressure vessel wall 1 along the width direction. C8 refers to the horizontal distance between the center of the first replaceable flow tube assembly 201 and the long side of the pressure vessel wall 1, which is closest to the long side of the pressure vessel wall 1 along the width direction.

[0037] C2 refers to the horizontal distance between the center of the first fixed flow tube 301 and the center of the second replaceable flow tube assembly 202 along the length of the pressure vessel wall 1; and the horizontal distance between the center of the second fixed flow tube 302 and the center of the second replaceable flow tube assembly 202. C4 refers to the horizontal distance between the center of the third fixed flow tube 303 and the center of the second replaceable flow tube assembly 202 along the length of the pressure vessel wall 1. C6 refers to the horizontal distance between the center of the fourth fixed flow tube 304 and the center of the fifth replaceable flow tube assembly 205 along the width of the pressure vessel wall 1. C9 refers to the horizontal distance between the center of the second fixed flow tube 302 and the horizontal lines containing the second replaceable flow tube assembly 202, the third replaceable flow tube assembly 203, the fourth replaceable flow tube assembly 204, and the fifth replaceable flow tube assembly 205 along the width of the pressure vessel wall 1.

[0038] In at least one embodiment of this application, the pressure vessel wall 1 has a quadrilateral arc structure, and the number of multiple legs is 4, with the multiple legs evenly distributed at the four corners of the bottom end of the pressure vessel wall.

[0039] For example, refer to Figure 1 The four legs include the first leg 401, the second leg 402, the third leg 403, and the fourth leg 405.

[0040] The following detailed examples illustrate the specific implementation process of the simulation experimental device (or reactor bottom neutron flux tube simulator) applied to laser shock peening equipment and process verification, using specific embodiments.

[0041] Step 1: Preparation and Installation of Replaceable Flux Tube Assembly 2 1. First, conduct a comprehensive inspection of multiple replaceable flux tube assemblies (e.g., 201-205) to confirm that their materials, machining precision, and structural integrity meet design requirements. Prepare specialized tools and lifting equipment, ensuring all tools are in good working order. Based on the actual layout within the reactor and the density of flux tubes, select suitable unprocessed replaceable flux tube assemblies, ensuring that the assemblies have similar geometric dimensions, material properties, and surface conditions to the actual reactor flux tubes.

[0042] 2. Hoist the replaceable flux tube assembly 2 to the designated location. During hoisting, adjust the lifting points of the hoisting equipment to keep the assembly horizontal and stable. When the assembly approaches the installation position, slowly reduce the speed to ensure accurate positioning.

[0043] 3. Using a torque wrench or similar tool, tighten the connecting bolts and locating pins between the replaceable flow tube assembly 2 and the pressure vessel wall to the specified torque value. During tightening, pay attention to the tightening sequence and the uniformity of the tightening torque to prevent assembly deformation or leakage due to improper tightening. Simultaneously, check and confirm that all bolts and locating pins are correctly installed and securely tightened.

[0044] 4. After installation, conduct a comprehensive inspection and test on the replaceable flux tube assembly 2. Confirm that the installation quality of the assembly meets the design requirements, and that there are no loose parts, vibrations, or other abnormalities.

[0045] Step Two: Installation of Laser Shock Enhancement Equipment and Laser Shock Processing The laser shock peening equipment is installed directly above the flux tube. After confirming that the installation position and orientation of the laser shock peening equipment are correct, laser shock processing is carried out according to the predetermined laser shock process.

[0046] Step 3: Replacement of replaceable flux tube assembly 2 and verification of impact effect 1. Using a specialized tool, gradually loosen the connecting bolts between the replaceable flow tube assembly and the pressure vessel wall 1. Bolt removal must be performed in a specific sequence and with appropriate torque to prevent deformation or damage to the assembly due to uneven stress. Simultaneously, gently pull out the locating pin, ensuring it does not damage surrounding components during disassembly.

[0047] 2. Install the strength-tested special lifting lug into the internal threaded hole at the top of the flow tube. Use lifting equipment to smoothly lift the replaceable flow tube assembly 2, maintaining a uniform speed and avoiding sudden acceleration or deceleration. If the assembly gets stuck, gently tap the outside of the assembly to help it come out, but control the force and direction of the tapping.

[0048] 3. Replace the unprocessed replaceable flux tube assembly with a new one, change the parameters, and continue the experiment. Perform corresponding performance tests on the processed replaceable flux tube assembly to verify the laser shock peening effect.

[0049] Through detailed operation and precise control of the above steps, the working performance of laser shock strengthening equipment in complex environments and the strengthening effect of laser shock technology on simulated components can be evaluated more comprehensively and accurately.

[0050] It should be noted that the combination of the technical features in the embodiments of this application is not limited to the combination methods described in the embodiments of this application or the combination methods described in specific embodiments. All technical features described in this application can be freely combined or combined in any way, unless they contradict each other.

[0051] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that it includes the explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0052] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A simulation experimental apparatus for the bottom of a nuclear power reactor, characterized in that, Includes a pressure vessel wall, multiple replaceable flow tube assemblies, multiple stationary flow tubes, and at least one support leg. At least one support leg is installed at the bottom edge of the pressure vessel wall to support the pressure vessel wall; multiple replaceable flow tube assemblies and multiple fixed flow tubes penetrate the pressure vessel wall and are detachably installed from the pressure vessel wall; the top of the fixed flow tube is provided with at least one quick-release interface for connecting external processing equipment.

2. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The pressure vessel wall is provided with multiple square grooves corresponding to multiple replaceable flow tube assemblies. The side walls of the square grooves are provided with positioning pin holes that match the positioning pins on the replaceable flow tube assemblies. The bottom of the square grooves is equipped with built-in bolts.

3. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 2, characterized in that, The replaceable flow tube assembly includes a replaceable flow tube and a base. The replaceable flow tube is mounted on the base, which is placed in a square groove on the pressure vessel wall and connected to the pressure vessel wall with bolts.

4. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The replaceable flux tube assembly is designed with threaded interfaces and locating pin slots that correspond to the bottom assembly.

5. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The replaceable flux tube assembly has a threaded hook on top.

6. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The replaceable flux tube assembly employs a shoulder restraint and positioning mechanism.

7. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, Multiple replaceable flux tube assemblies are of different sizes, and / or multiple fixed flux tubes are of different sizes.

8. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The number of replaceable flow tube assemblies is five. The five replaceable flow tube assemblies include a first replaceable flow tube assembly, a second replaceable flow tube assembly, a third replaceable flow tube assembly, a fourth replaceable flow tube assembly, and a fifth replaceable flow tube assembly. The second replaceable flow tube assembly, the third replaceable flow tube assembly, the fourth replaceable flow tube assembly, and the fifth replaceable flow tube assembly are arranged side by side along the length of the pressure vessel wall, and the first replaceable flow tube assembly and the second replaceable flow tube assembly are arranged side by side along the width of the pressure vessel wall.

9. The simulation experimental apparatus for the bottom of a nuclear power reactor according to claim 1, characterized in that, The number of fixed flow tubes is four. The four fixed flow tubes include a first fixed flow tube, a second fixed flow tube, a third fixed flow tube, and a fourth fixed flow tube. The first and second fixed flow tubes are arranged side by side along the width direction of the pressure vessel wall, and the third and fourth fixed flow tubes are arranged side by side along the length direction of the pressure vessel wall.

10. A simulation experimental apparatus for the bottom of a nuclear power reactor according to any one of claims 1 to 9, characterized in that, The pressure vessel wall has a quadrilateral arc structure, and there are four support legs, which are evenly distributed at the four corners of the bottom of the pressure vessel wall.

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