Nuclear reactor vessel bottom penetration hole pitch measuring device and method

Abstract

The application belongs to the technical field of in-service plant maintenance of pressurized water reactor nuclear power units, and discloses a device and a method for measuring the hole distance of a bottom penetration of a nuclear reactor pressure vessel, wherein the device comprises a power transmission system, a motion system, a measuring system and a long rod connecting system; the linear module of the motion system is connected with the gear shaft of the power transmission system and is provided with an encoder cabin; a screw rod is arranged in the linear module and is connected with a sliding block; the measuring system comprises a measuring module cavity, a measuring module mounting plate, a measuring module adapter plate, a cable sealing module and a pumping assembly; and the measuring module adapter plate is connected with the sliding block; and the method utilizes the device to measure the hole distance. The application can measure the hole distance of the bottom penetration of the nuclear reactor pressure vessel under the harsh environment of high radiation and water, so as to realize the regular monitoring of the hole distance data of the bottom penetration of the pressure vessel.

Description

Technical Field

[0001] This application belongs to the field of maintenance technology for in-service pressurized water reactor nuclear power plants, and particularly relates to a device and method for measuring the hole spacing of the bottom penetration of a nuclear reactor pressure vessel. Background Technology

[0002] Nuclear power generation utilizes the heat released from the self-sustaining chain fission reaction of nuclear fuel to generate electricity. After the initial criticality of a pressurized water reactor nuclear power plant, the nuclear fuel assemblies, primary loop system, and equipment are highly radioactive, making the maintenance environment extremely harsh. Maintenance personnel cannot approach them normally, and conventional methods cannot be used for maintenance operations.

[0003] Nuclear power plant pressure vessels and other primary loop equipment are exposed to high radiation environments for extended periods, necessitating regular condition monitoring. Currently, measuring devices are needed to detect equipment characteristics, providing reliable and fundamental data support for equipment maintenance. As a critical and sensitive non-replaceable component of the primary loop, the nuclear reactor pressure vessel operates in extremely harsh environments, particularly its bottom penetrations. With the increasing operational lifespan of nuclear power units, there is a need to develop a measuring device for the bottom penetrations of nuclear reactor pressure vessels. Summary of the Invention

[0004] The purpose of this application is to provide a device and method for measuring the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel, which can measure the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel in a harsh underwater environment with high radiation, thereby enabling regular monitoring of the hole spacing data of the bottom penetrations of the pressure vessel.

[0005] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application provides a device for measuring the hole spacing of the bottom penetration section of a nuclear reactor pressure vessel, characterized in that it includes: A power transmission system has a gearbox, in which a first gear shaft and a second gear shaft are arranged and meshed through gears for transmission. The second gear shaft is connected to a motor via a transition shaft. The motion system has a linear module, one end of which is connected to the first gear shaft, and the other end is equipped with an encoder housing. A lead screw is arranged inside the linear module, and the lead screw is connected to a slider. A measurement system has a sealed measurement module cavity and a measurement module cavity cover. A measurement module mounting plate is provided on the side of the measurement module cavity. The measurement module mounting plate is connected to a measurement module adapter plate, and the measurement module adapter plate is connected to the slider. A long rod connection system having a rotatably connected long rod sleeve and a long rod sleeve seat, the long rod sleeve being used to mount the long rod.

[0006] As one possible implementation, the motor is mounted on a motor mount, which is positioned and fixedly mounted on the motor housing cover via a flange.

[0007] As one possible approach, the motor is housed within a motor compartment, and the motor compartment and the motor compartment cover are coaxially mounted and statically sealed.

[0008] As one possible implementation, the adapter shaft is coaxially mounted with the motor housing, with one end of the adapter shaft mounted at the front end of the motor and the other end mounted inside the second gear shaft and arranged coaxially.

[0009] As one possible implementation, the encoder compartment is equipped with a coupling and an encoder, the coupling connecting the encoder and the lead screw.

[0010] As one feasible approach, an encoder compartment cover is installed at one end of the encoder compartment, and a sealing adapter is provided at the other end. The sealing adapter and the linear module form a static seal by installing a sealing ring.

[0011] As one feasible approach, the encoder housing is provided with an air inlet and a cable outlet. An air nozzle is installed in the air inlet and is limited by the flange of the air inlet. The air nozzle is then pressed tightly with an air nozzle clamping nut. A third cable sealing module is installed on the cable outlet.

[0012] As one possible implementation, a Hall effect sensor and an electrical box are mounted on the side of the linear module; the number of sliders is two, one of which is equipped with a magnet holder with a magnet.

[0013] As one possible implementation, a second cable sealing module is mounted on the measuring module mounting plate, and an air inflator is mounted on the measuring module cavity.

[0014] Secondly, this application provides a method for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel, employing the aforementioned device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel, including: Step 1: Use an underwater long rod to lower the hole spacing measuring device at the bottom of the nuclear reactor pressure vessel to a suitable height inside the pressure vessel and keep it relatively fixed; Step 2: Operate the measurement system to the measurement position via the industrial control computer. The measurement fields of the two binocular measurement modules respectively cover the bottom of the pressure vessel through-hole component being measured. Step 3: Use two binocular measurement modules to collect point cloud data of the penetrating component at the bottom of a single pressure vessel; Step 4: Unify the spatial coordinates of the cloud data collected by the two binocular measurement modules, remove noise, and generate point cloud data of the tested penetrating component at the bottom of the pressure vessel. Step 5: Measure the point cloud data of the tested through-hole component at the bottom of the pressure vessel to obtain its shape and dimensions.

[0015] Compared with the prior art, the device and method for measuring the hole spacing of the bottom penetration of the nuclear reactor pressure vessel provided in this application have the following advantages: This application enables the measurement of the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel in harsh underwater environments with high radiation, thereby achieving regular monitoring of the hole spacing data of the bottom penetrations of the pressure vessel.

[0016] This application designs an underwater binocular measurement module based on the principle of binocular measurement to realize aperture size measurement in a small field of view area.

[0017] Furthermore, this application utilizes two underwater binocular measurement modules, combined with a linear motion mechanism and displacement sensors such as encoders (which can adjust the distance between the two underwater binocular measurement modules and accurately feedback the distance), to achieve aperture size measurement within a large field of view. Attached Figure Description

[0018] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the technical description will be briefly introduced below.

[0019] Figure 1 Axonometric drawing of the hole spacing measuring device for the bottom penetration of a nuclear reactor pressure vessel provided in this application; Figure 2 A partial sectional view of the power input portion provided in this application; Figure 3 The isometric drawing of the motion system provided for this application; Figure 4 This application provides a cross-sectional view of the encoder mounting in the power transmission system. Figure 5 Axonometric drawing of the measurement system provided in this application; Figure 6 A flowchart illustrating the method for measuring the hole spacing at the bottom of the nuclear reactor pressure vessel provided in this application.

[0020] Explanation of reference numerals in the attached figures: 1. Gearbox; 2. Gearbox cover; 3. Gear; 4. First gear shaft; 5. Motor compartment cover; 6. Second gear shaft; 7. Adapter shaft; 8. Motor base; 9. Motor compartment; 10. Motor compartment rear cover; 11. First cable sealing module; 12. Linear module; 13. Long rod sleeve; 14. Long rod sleeve seat; 15. Electrical box; 16. Encoder compartment; 17. Slider; 18. Hall effect sensor; 19. Magnet seat; 20. Measurement module cavity cover; 21. Measurement module cavity; 22. Measurement module adapter plate; 23. Second cable sealing module; 24. Measurement module mounting plate; 25. Air inflator assembly; 26. Sealing adapter; 27. Coupling; 28. Encoder; 29. ​​Encoder compartment cover; 30. Air nozzle; 31. Air nozzle clamping nut; 32. Third cable sealing module. Detailed Implementation

[0021] The following detailed description provides further details on specific implementation methods.

[0022] like Figures 1 to 5 As shown, this application provides a device for measuring the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel, including a power transmission system, a motion system, a measurement system, and a long rod connection system. This device can measure the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel in harsh underwater environments with high radiation, thereby enabling periodic monitoring of the hole spacing data.

[0023] like Figure 2 As shown, the power transmission system includes a motor compartment 9, a first cable sealing module 11, a motor compartment cover 5, a motor compartment rear cover 10, a motor, a motor base 8, a transfer shaft 7, a gear 3, a gearbox 1, a gearbox cover 2, a first gear shaft 4, and a second gear shaft 6.

[0024] The motor compartment 9 is a thin-walled rotating structure. The motor compartment 9 and the motor compartment cover 5 are coaxially mounted and statically sealed, providing a sealed environment for the motor and other electrical equipment. The motor is mounted on the motor mount 8, which is positioned relative to the motor via a motor flange. The motor mount 8 is positioned and fixedly mounted on the motor compartment cover 5 via a flange.

[0025] The adapter shaft 7 is coaxially mounted with the motor compartment 9. One end of the adapter shaft 7 is mounted at the front end of the motor, and the other end is mounted inside the second gear shaft 6, arranged coaxially with the second gear shaft 6.

[0026] The gearbox 1 contains two identical gears 3, which are coaxially mounted to the first gear shaft 4 and the second gear shaft 6, respectively. Figure 2 As shown, the left gear 3 is mounted on the first gear shaft 4, and the right gear 3 is mounted on the second gear shaft 6. The left gear 3 and the right gear 3 mesh.

[0027] The first gear shaft 4 is positioned by a shoulder and a bearing on the gearbox 1. The gearbox cover 2 is mounted on the upper part of the gearbox 1 and is positioned by a bearing on the gearbox cover 2. Similarly, the second gear shaft 6 is positioned by a shoulder and a bearing on the gearbox 1, and is positioned by a bearing on the gearbox cover 2.

[0028] Preferably, both the gearbox 1 and the gearbox cover 2 adopt a hollow structure to reduce weight.

[0029] Preferably, gear 3 adopts a hollow structure to reduce weight.

[0030] like Figure 3 As shown, the motion system includes a linear module 12, an encoder compartment 16, an encoder compartment cover 29, an encoder 28, a third cable sealing module 32, a coupling 27, a sealing adapter 26, an air nozzle 30, an air nozzle clamping nut 31, a Hall effect sensor 18, a slider 17, an electrical box 15, a magnet base 19, and a magnet.

[0031] The linear module 12 is a linear module suitable for the underwater environment of nuclear reactors. The structure of the linear module 12 suitable for underwater environments is similar to that of general modules, but each part is mechanically and materially waterproofed, making it suitable for underwater environments.

[0032] The lead screw inside the linear module 12 is a left- or right-handed ball screw, which is connected to two sliders 17. When the lead screw rotates, the sliders 17 can move simultaneously in the same direction or in opposite directions. The two sliders 17 are arranged symmetrically with respect to the center plane of the lead screw.

[0033] The end of the linear module 12 (e.g.) Figure 3 The front end (as shown) is equipped with an encoder housing 16, and the other end of the linear module 12 is connected to the first gear shaft 4 and fixed to the gearbox 1. The first gear shaft 4 and the lead screw are connected and driven by a coupling.

[0034] like Figure 3 As shown, the Hall effect sensor 18 is mounted on the side (left side) of the linear module 12. Two sliders 17 of the linear module 12 are mounted on its bottom. A magnet holder 19 is mounted on one of the sliders 17, and a magnet is provided on the magnet holder 19. The magnet is fixed to the magnet holder 19, for example, by screws. An electrical box 15 is mounted on the right side of the linear module 12. The purpose of the electrical box 15 is to process motor control signals, reduce the number of cables above and below water, and make the equipment simpler.

[0035] like Figure 4As shown, the encoder compartment 16 houses a coupling 27 and an encoder 28. An encoder compartment cover 29 is mounted at the front end, and a sealing adapter 26 is located at the rear end, fixed to the base. The encoder compartment 16 and the encoder 28 are positioned and mounted via the flange of the encoder 28. The coupling 27 connects the encoder 28 to the lead screw of the linear module 12 (the front end of the coupling 27 connects to the encoder 28, and the rear end connects to the lead screw of the linear module 12). The sealing adapter 26 forms a static seal with the linear module 12 through the installation of a sealing ring, and a dynamic seal with the lead screw of the linear module 12.

[0036] The encoder housing 29 is designed with an air inlet and a cable outlet. An air nozzle 30 is installed in the air inlet and is limited by the flange of the air inlet. The air nozzle 30 is pressed by the air nozzle clamping nut 31. A third cable sealing module 32 is installed on the cable outlet for sealing the cable.

[0037] like Figure 5 As shown, the measurement system includes two binocular measurement modules. Each binocular measurement module has a measurement module cavity 21, a measurement module cavity cover 20, a measurement module mounting plate 24, a measurement module adapter plate 22, a second cable sealing module 23, and an air inflator 25. The air inflator 25 is existing technology and is directly installed via threads. Its function is to inflate the module and balance the pressure generated underwater. The measurement module cavity 21 and the measurement module cavity cover 20 form a sealed environment through a hydrostatic sealing ring. The measurement module mounting plate 24 is installed on the side of the binocular measurement module and is fixed to the measurement module adapter plate 22 with screws. The slider 17 has a pre-drilled threaded hole for installing the measurement module adapter plate 22.

[0038] This application employs a second cable sealing module 23 to prevent cable bending. The second cable sealing module 23 is mounted on the measurement module mounting plate 24, and the air inflator 25 is mounted on the measurement module cavity 21.

[0039] Preferably, the two binocular measurement modules are installed at intervals below the linear module 12.

[0040] like Figure 1 and Figure 3 As shown, a long rod connection system is installed on the upper part of the linear module 12 for connecting with long rods used in the field. The long rod connection system includes a long rod sleeve 13 and a long rod sleeve seat 14. A pin hole is provided on the upper part of the long rod sleeve 13. After the long rod is inserted into the long rod sleeve 13, a locking pin passes through the pin hole to fix the long rod to the long rod sleeve 13. The bottom of the long rod sleeve 13 has a double-cut arc surface, and through holes are machined on the double-cut surfaces.

[0041] The long rod sleeve seat 14 has a groove cut in the middle. The left end of the groove is a threaded hole, and the right end is a screw through hole. The double-cut surface of the long rod sleeve 13 is nested into the groove of the long rod sleeve seat 14. The angle between the long rod and the linear module 12 is adjusted by tightening or loosening the bolt. When the bolt is loosened, the long rod sleeve 13 and the long rod sleeve seat 14 can rotate relative to each other. When the bolt is tightened, the long rod sleeve 13 and the long rod sleeve seat 14 cannot rotate relative to each other.

[0042] Furthermore, based on the aforementioned device for measuring the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel, this application also provides a method for measuring the hole spacing of the bottom penetrations of a nuclear reactor pressure vessel, such as... Figure 6 As shown, it includes the following steps: Step 1: Use an underwater long pole to transport the hole spacing measuring device at the bottom of the nuclear reactor pressure vessel to a suitable height inside the pressure vessel (the location to be measured) and keep it relatively fixed (if necessary, lifting equipment and hoisting tools can be used). Step 2: Operate the measurement system to a suitable position using an industrial control computer. The measurement fields of the two measurement systems can respectively cover (achieved by controlling the movement of the motor) the bottom of the pressure vessel to be measured through the penetrating part. Step 3: Use two measurement systems to collect point cloud data of the penetrating component at the bottom of a single pressure vessel; Step 4: Unify the spatial coordinates of the cloud data collected by the two measurement systems above, remove noise, and generate point cloud data of the tested penetrating component at the bottom of the pressure vessel. Step 5: Measure the point cloud data of the penetrated part at the bottom of the pressure vessel using software (equipped with a control box, which has the corresponding software installed) to obtain the shape and position dimensions.

[0043] Before using this device and implementing the above method, the following prerequisites must be met: (1) Visual inspection: Inspect and confirm that the fasteners are securely connected and that there are no abnormalities in their appearance; (2) Equipment connection: Check and confirm that the power cord and all cables are connected correctly and reliably; (3) System startup: Check and confirm that all functions and parameters are normal (including but not limited to: barometer, depth gauge, thermometer, etc.); (4) Functional check: Check and confirm that all functions are normal; (5) Equipment calibration: The equipment accuracy calibration has been completed; (6) On-site conditions: On-site ventilation and lighting are normal, the on-site radiation monitoring system is running continuously, and the conditions for equipment hoisting and use are met.

[0044] The above description is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A device for measuring the hole spacing of the bottom penetration section of a nuclear reactor pressure vessel, characterized in that, include: The power transmission system has a gearbox (1), in which a first gear shaft (4) and a second gear shaft (6) are arranged and meshed through a gear (3). The second gear shaft (6) is connected to a motor through a transfer shaft (7). The motion system has a linear module (12), one end of which is connected to the first gear shaft (4), and the other end is equipped with an encoder housing (16). A lead screw is arranged inside the linear module (12), and the lead screw is connected to a slider (17). The measurement system includes two binocular measurement modules, each of which has a sealed measurement module cavity (21) and a measurement module cavity cover (20). The side of the measurement module cavity (21) is provided with a measurement module mounting plate (24), which is connected to a measurement module adapter plate (22). The measurement module adapter plate (22) is connected to the slider (17). The long rod connection system has a rotatably connected long rod sleeve (13) and long rod sleeve seat (14), the long rod sleeve (13) being used to mount the long rod.

2. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 1, characterized in that, The motor is mounted on a motor mount (8), and the motor mount (8) is positioned and fixedly mounted on the motor mount (5) by the flange of the motor housing cover (5).

3. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 2, characterized in that, The motor is located inside the motor compartment (9), and the motor compartment (9) and the motor compartment cover (5) are coaxially installed and statically sealed.

4. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 3, characterized in that, The adapter shaft (7) is coaxially mounted with the motor housing (9). One end of the adapter shaft (7) is mounted on the front end of the motor, and the other end is mounted inside the second gear shaft (6) and arranged coaxially.

5. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 1, characterized in that, The encoder compartment (16) is equipped with a coupling (27) and an encoder (28), and the coupling (27) connects the encoder (28) and the lead screw.

6. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 1, characterized in that, The encoder compartment (16) has an encoder compartment cover (29) installed at one end and a sealing adapter (26) at the other end. The sealing adapter (26) and the linear module (12) form a static pressure seal by installing a sealing ring.

7. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 6, characterized in that, The encoder housing (29) is provided with an air inlet and a cable outlet. An air nozzle (30) is installed in the air inlet and is limited by the flange of the air inlet. The air nozzle (30) is pressed by the air nozzle clamping nut (31). A third cable sealing module (32) is installed on the cable outlet.

8. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 1, characterized in that, The side of the linear module (12) is equipped with a Hall sensor (18) and an electrical box (15); there are two sliders (17), one of which is equipped with a magnet seat (19) and a magnet is provided on the magnet seat (19).

9. The device for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel according to claim 1, characterized in that, A second cable sealing module (23) is installed on the measuring module mounting plate (24), and an air pumping component (25) is installed on the measuring module cavity (21).

10. A method for measuring the hole spacing of the bottom penetration member of a nuclear reactor pressure vessel, characterized in that, The device for measuring the hole spacing of the bottom penetration of a nuclear reactor pressure vessel according to any one of claims 1 to 9 includes: Step 1: Use an underwater long rod to lower the hole spacing measuring device at the bottom of the nuclear reactor pressure vessel to a suitable height inside the pressure vessel and keep it relatively fixed; Step 2: Operate the measurement system to the measurement position via the industrial control computer. The measurement fields of the two binocular measurement modules respectively cover the bottom of the pressure vessel through-hole component being measured. Step 3: Use two binocular measurement modules to collect point cloud data of the penetrating component at the bottom of a single pressure vessel; Step 4: Unify the spatial coordinates of the point cloud data collected by the two binocular measurement modules, remove noise, and generate point cloud data of the tested penetrating component at the bottom of the pressure vessel. Step 5: Measure the point cloud data of the tested through-hole component at the bottom of the pressure vessel to obtain its shape and dimensions.

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