Automatic maintenance device for main sealing pair and main bolt of nuclear power main cooling pump

Abstract

The present application belongs to the technical field of nuclear power plant pump maintenance, and particularly relates to a nuclear power main cooling pump main sealing pair and main bolt automatic maintenance device. The device comprises a frame base, the frame base comprises a lower fixed platform and an upper rotary platform, the upper rotary platform is provided with a main bolt hole cleaning module, a main bolt hole air drying module, a main bolt hole polishing module, a main bolt hole oiling module, a hole flange face cleaning module, a main bolt hole inspection module, a sealing surface inspection module, a rotary body rotating motor and a sealing surface cleaning module through installation of supporting blocks or direct installation through bolts. The device has the beneficial effects that it is suitable for checking and cleaning the sealing surface defects of nuclear power plant main pumps of a certain size, and is suitable for cleaning, checking, maintaining and maintaining the main bolt holes. The device is precisely positioned through contact and non-contact, and the operation module is replaced in real time through intelligent equipment, so that the maintenance efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power plant pump maintenance technology, specifically relating to an automatic maintenance device for the main sealing pair and main bolts of a nuclear power plant main cooling pump. Background Technology

[0002] The main sealing surfaces and main bolts of the main pumps in nuclear power plants are crucial components of the primary loop radioactive boundary, making their maintenance extremely important. However, due to the high quality requirements for inspection of the main sealing surfaces and main bolt holes, the confined working space, and the high dose rate, maintenance work is labor-intensive, time-consuming, and exposes personnel to significant radiation exposure. Currently, the condition inspection of the main pump's main bolt thread holes and sealing surfaces involves two methods: either manual inspection using supports to mount inspection equipment, or using a crawler trolley to carry the inspection and maintenance equipment. These existing methods have the following problems:

[0003] (1) The manual maintenance method with the help of brackets is labor-intensive and has a low level of automation;

[0004] (2) The manual maintenance method with the aid of a support frame takes a long time and exposes personnel to a large amount of radiation.

[0005] (3) The manual inspection method with the help of a support frame is inconvenient and has a significant impact on the accuracy of the inspection work;

[0006] (4) The maintenance method using a crawler trolley has poor compatibility, cannot be used with multiple crawling devices, and has low work efficiency.

[0007] With increasingly stringent nuclear safety requirements, in order to improve the quality of maintenance work on the main sealing surfaces and threaded holes of the main pumps in nuclear power plants, reduce labor intensity, and lower the radiation dose to personnel, it is necessary to develop a new type of automatic maintenance device for the main sealing surfaces and main bolts of nuclear power plants. Summary of the Invention

[0008] The purpose of this invention is to provide an automatic maintenance device for the main sealing pair and main bolts of the main cooling pump in nuclear power plants, which can solve the problems of cleaning, drying, inspecting, polishing and oiling the main bolt holes of the main pump in nuclear power plants, as well as cleaning and inspecting the sealing surfaces.

[0009] The technical solution of the present invention is as follows: An automatic maintenance device for the main sealing pair and main bolts of a nuclear power plant main cooling pump includes a frame base. The frame base includes a lower fixed platform and an upper rotating platform. The outer layer of the frame base is provided with a shielding shell. The lower fixed platform is provided with a shielding grid inside. The upper rotating platform is also fitted with a slewing bearing. The upper rotating platform is equipped with a main bolt hole cleaning module, a main bolt hole drying module, a main bolt hole polishing module, a main bolt hole oiling module, a flange surface cleaning module, a main bolt hole inspection module, a sealing surface inspection module, a rotating motor, and a sealing surface cleaning module, which are installed on the upper rotating platform by means of support blocks or directly by bolts. The upper rotating platform is connected to the shielding device through the slewing bearing.

[0010] The main bolt hole cleaning module includes a first quick-change fixture, a first rotary motor, a first cleaning brush, a waste liquid suction pipe, a cleaning liquid supply pipe, and a first fixed base. The lower part of the first quick-change fixture is connected to the first fixed base with a hollow structure. The first rotary motor is installed inside the first fixed base. Two first cleaning brushes are symmetrically connected to the rotating shaft of the first rotary motor. The waste liquid suction pipe and the cleaning liquid supply pipe are also installed inside the first fixed base. The first cleaning brush is driven to rotate by the first rotary motor. The first cleaning brush rotates circumferentially around the threaded surface to achieve cleaning of the entire threaded surface.

[0011] The main bolt hole drying module includes a second quick-change fixture, a second fixed base, and a hot air gun. The two ends of the second fixed base are respectively connected to the second quick-change fixture and the hot air gun. The hot air gun realizes the heating and blowing action through the electrical contact of the mounting contacts of the second quick-change fixture.

[0012] The main bolt hole inspection module includes a third quick-change fixture, a camera, and a prism. The camera is connected to the third quick-change fixture, and the prism is located below the camera. During inspection, the prism is inserted into the threaded hole and rotates around the thread wall to export the thread image, which is then captured by the camera.

[0013] The main bolt hole polishing module includes a fourth quick-change fixture, a second rotary motor, a second cleaning brush, a negative pressure suction pipe, and a third fixed base. The fourth quick-change fixture is connected to the hollow third fixed base. The second rotary motor is housed inside the third fixed base. Two second cleaning brushes are connected to the shaft of the second rotary motor. The negative pressure suction pipe is also connected inside the third fixed base.

[0014] The main bolt hole oiling module includes a fifth quick-change fixture, a third rotary motor, felt wheels, an oil storage pipe, and a fourth fixed seat. The fifth quick-change fixture is connected to the hollow fourth fixed seat, and the third rotary motor is housed inside the fourth fixed seat. Two felt wheels are connected to the shaft of the third rotary motor, and the oil storage pipe is also connected to the fourth fixed seat. The felt wheels rotate around the threaded wall, and the oil squeezed out by the oil storage pipe is brushed onto the bolt hole wall by the felt wheels.

[0015] The sealing surface cleaning module includes a sixth quick-change fixture, a fourth rotary motor, a cleaning wheel, a belt drive, and a fifth fixed base. The sixth quick-change fixture is connected to the fifth fixed base with a frame structure. The fourth rotary motor is installed inside the fifth fixed base. The rotating shaft of the fourth rotary motor drives the cleaning wheel through the belt drive. The fourth rotary motor drives the cleaning wheel to rotate and the turntable to rotate, which in turn moves the sealing surface cleaning module on the sealing surface to clean the sealing surface.

[0016] The sealing surface inspection module includes a sixth fixed base, a line array camera, and a light source. The lower part of the sixth fixed base is connected to two line array cameras via a mounting bracket, and the light source is connected to the sixth fixed base via a mounting bracket. The light source is located between the two line array cameras. The line array camera detects damage and scratches on the sealing surface of the main pump.

[0017] The beneficial effects of this invention are as follows: The automatic inspection and maintenance device for the main sealing surface and main bolts of the nuclear power plant main pump has been verified through testing. Tests show that this device is suitable for inspecting and cleaning defects in the sealing surface of nuclear power plant main pumps of a certain size, and for cleaning, inspecting, and maintaining the main bolt holes. Precise positioning of the device is achieved through contact and non-contact technologies; and the efficiency of inspection and maintenance is improved through real-time replacement of operating modules using intelligent equipment. Compared with existing technologies, this invention, in addition to its inspection function, solves the problem of integrating multi-functional modules in small spaces, while also adding a shielding function, improving its applicability to large equipment. A single installation can cover all working areas, improving work efficiency. Attached Figure Description

[0018] Figure 1 A top view of an automatic maintenance device for the main sealing pair and main bolts of a nuclear power plant main cooling pump provided by the present invention;

[0019] Figure 2 This is a schematic diagram of the frame base (including the lower fixed platform with a shielded room);

[0020] Figure 3 This is a schematic diagram of the robotic arm's operating area;

[0021] Figure 4 Schematic diagram of the main bolt hole cleaning module;

[0022] Figure 5 Schematic diagram of the main bolt hole drying module;

[0023] Figure 6 Schematic diagram of the main bolt hole inspection module;

[0024] Figure 7 Schematic diagram of the main bolt hole polishing module;

[0025] Figure 8 Schematic diagram of the main bolt hole oiling module;

[0026] Figure 9 Schematic diagram of the sealing surface cleaning module;

[0027] Figure 10 This is a schematic diagram of the sealing surface inspection module;

[0028] Figure 11 This is a simplified flowchart of the automatic maintenance device operation process.

[0029] In the diagram: 9. Main bolt hole cleaning module; 10. Main bolt hole drying module; 11. Main bolt hole polishing module; 12. Main bolt hole oiling module; 13. Flange surface cleaning module; 14. Main bolt hole inspection module; 15. Sealing surface inspection module; 16. Rotating body rotary motor; 17. Sealing surface cleaning module; 18. Rotating bearing; 19. Shielding housing; 20. Shielding grid; 21. Rotating area of ​​the rotating body; 22. Robotic arm activity area; 23. First quick-change tooling; 24. First rotary motor; 25. First cleaning brush; 26. Waste liquid suction pipe; 27. Cleaning fluid supply pipe; 28. ... 1. Fixed base; 29. ​​Second quick-change fixture; 30. Second fixed base; 31. Hot air gun; 32. Third quick-change fixture; 33. Camera; 34. Prism; 35. Fourth quick-change fixture; 36. Second rotary motor; 37. Second cleaning brush; 38. Negative pressure suction pipe; 39. Third fixed base; 40. Fifth quick-change fixture; 41. Third rotary motor; 42. Felt wheel; 43. Oil reservoir pipe; 44. Fourth fixed base; 45. Sixth quick-change fixture; 46. Fourth rotary motor; 47. Cleaning wheel; 48. Belt drive; 49. Fifth fixed base; 50. Sixth fixed base; 51. Line scan camera; 52. Light source. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, the present invention provides an automatic maintenance device for the main sealing pair and main bolts of a nuclear power plant main cooling pump, including a frame base, as shown in the figure. Figure 2As shown, the frame base, comprising a lower fixed platform with a shielded chamber and an upper rotating platform, forms the physical foundation for the entire sealing surface and the main bolt hole operating equipment. It supports the entire equipment and provides positioning. Its outer layer is designed with a shielding shell 19, providing radiation protection for operators and equipment. The lower fixed platform is a circular platform, primarily made of austenitic stainless steel. In addition to a sufficient lead shielding layer poured inside, it provides good protection for personnel and equipment. An internal steel plate grid structure shielding grille 20 is also welded in, reinforcing its support. The lower fixed platform is designed with flexible sealing strips to prevent impurities and debris from mixing with each other or falling into the hydraulic components of the main pump during operation. The upper rotary platform is a circular platform with austenitic stainless steel as the main material. A rotary bearing 18 is also installed on the upper rotary platform. The upper rotary platform is equipped with a main bolt hole cleaning module 9, a main bolt hole drying module 10, a main bolt hole polishing module 11, a main bolt hole oiling module 12, a flange surface cleaning module 13, a main bolt hole inspection module 14, a sealing surface inspection module 15, a rotary motor 16, and a sealing surface cleaning module 17. The upper rotary platform is connected to the shielding device through the rotary bearing 18.

[0032] like Figure 4 As shown, the main bolt hole cleaning module includes a first quick-change fixture 23, a first rotary motor 24, a first cleaning brush 25, a waste liquid suction pipe 26, a cleaning liquid supply pipe 27, and a first fixed base 28. The lower part of the first quick-change fixture 23 is connected to a hollow first fixed base 28. The first rotary motor 24 is housed within the first fixed base 28. Two first cleaning brushes 25 are symmetrically connected to the rotating shaft of the first rotary motor 24. The waste liquid suction pipe 26 and the cleaning liquid supply pipe 27 are also installed within the first fixed base 28. The first cleaning brushes 25 are driven to rotate by the first rotary motor 24 and are pressed against the threaded surface. Simultaneously, driven by the sixth axis of the robot, the first cleaning brushes 25 rotate circumferentially around the threaded surface, achieving cleaning of the entire threaded surface. The first cleaning brushes 25 are made of nylon. The cleaning liquid supply pipe 27 is connected to a piston pump and a cylinder, allowing for intermittent injection of cleaning liquid into the main bolt hole. The first cleaning brushes 25 are immersed in the cleaning liquid, and the first rotary motor 24 drives the first cleaning brushes 25 to rotate, completing the cleaning of the bolt hole. After cleaning, the waste liquid is drawn back into the cleaning liquid storage tank through the waste liquid suction pipe 26. The storage tank is equipped with a filter screen to filter and recover impurities in the cleaning liquid so that the cleaning liquid can be recycled.

[0033] like Figure 5As shown, the main bolt hole drying module includes a second quick-change fixture 29, a second fixed base 30, and a hot air gun 31. The second fixed base 30 has the second quick-change fixture 29 and the hot air gun 31 connected to its two ends respectively. The hot air gun 31 achieves heating and blowing action through the electrical contact of the mounting contacts on the second quick-change fixture 29. The hot air gun 31 uses a high-power resistance heating wire and is equipped with an extended curved nozzle at its front end to facilitate airflow, allowing it to reach into the threaded hole and dry the threaded wall and bottom hole. Controlled by a robot, it can achieve multi-angle blowing.

[0034] like Figure 6 As shown, the main bolt hole inspection module includes a third quick-change fixture 32, a camera 33, and a prism 34. The camera 33 is connected to the third quick-change fixture 32, and the prism 34 is located below the camera 33. During inspection, the prism 34 is inserted into the threaded hole and rotates circumferentially around the thread wall under the control of a robot, exporting the thread image and then taking a picture with the camera. The thread quality is determined by comparing multiple frames.

[0035] After the camera takes a picture, it converts the optical image signal into a digital image signal and outputs it. Only one line of pixels is collected each time. The digital image signal is transmitted to the control part through network communication to complete the image stitching, analysis and processing and output, thereby judging the defect information of the bolt hole.

[0036] like Figure 7 As shown, the main bolt hole polishing module includes a fourth quick-change fixture 35, a second rotary motor 36, a second cleaning brush 37, a negative pressure suction pipe 38, and a third fixed base 39. The fourth quick-change fixture 35 is connected to a hollow third fixed base 39, which houses the second rotary motor 36. Two second cleaning brushes 37 are connected to the shaft of the second rotary motor 36. The negative pressure suction pipe 38 is also connected to the third fixed base 39. The polishing module is an important step in bolt hole cleaning. The polishing module and the cleaning module have the same design structure and movement. The difference is that two polishing brushes work simultaneously, which can shorten the polishing time. In addition, the polishing brushes are made of abrasive nylon.

[0037] like Figure 8 As shown, the main bolt hole oiling module includes a fifth quick-change fixture 40, a third rotary motor 41, felt wheels 42, an oil storage pipe 43, and a fourth fixed seat 44. The fifth quick-change fixture 40 is connected to a hollow fourth fixed seat 44, which houses the third rotary motor 41. Two felt wheels 42 are connected to the shaft of the third rotary motor 41. The oil storage pipe 43 is also connected to the fourth fixed seat 44. The felt wheels 42 rotate around the threaded wall, and the oil squeezed out by the oil storage pipe 43 is brushed onto the bolt hole wall through the felt wheels 42. When not in use, the central tube of the oil storage pipe 43 moves downward, the oil storage pipe and the hole of the central tube are misaligned, and the oil storage pipe stops discharging oil.

[0038] like Figure 9 As shown, the sealing surface cleaning module includes a sixth quick-change fixture 45, a fourth rotary motor 46, a cleaning wheel 47, a belt drive 48, and a fifth fixed base 49. The sixth quick-change fixture 45 is connected to the fifth fixed base 49 with a frame structure. The fourth rotary motor 46 is installed in the fifth fixed base 49. The rotating shaft of the fourth rotary motor 46 drives the cleaning wheel 47 through the belt drive 48. The sealing surface cleaning adopts a dry cleaning method. When in use, the robot grabs the sealing surface cleaning module and places it above the sealing surface. The fourth rotary motor 46 drives the cleaning wheel 47 to rotate and the turntable to rotate, which drives the sealing surface cleaning module to move on the sealing surface, thereby cleaning the sealing surface.

[0039] like Figure 10 As shown, the sealing surface inspection module includes a sixth fixed base 50, a line scan camera 51, and a light source 52. Two line scan cameras 51 are connected to the lower part of the sixth fixed base 50 via a mounting bracket. The light source 52 is connected to the sixth fixed base 50 via a mounting bracket, positioned between the two line scan cameras 51. The line scan cameras perform two functions: first, to detect damage and scratches on the main pump sealing surface. During sealing surface inspection, the camera is fixed on a rotating turntable, and the sealing surface inspection module moves across the sealing surface as the turntable rotates, performing a uniform scan of the sealing surface.

[0040] The robotic arm, model IRB1300-10 / 1.15, uses quick-change tooling and other components to pick up the aforementioned functional modules. A force sensor and quick-change module are installed at the end of the robotic arm to perform functions such as cleaning, drying, inspection, polishing, applying anti-seize agent, and cleaning and inspection of the main bolt holes. Simultaneously, the module provides real-time feedback on the force in the horizontal and vertical directions to prevent collisions. It inspects and repairs the main pump's main seals and main bolt holes. The robotic arm's reach area reaches a radius of 1150mm, and in conjunction with the upper rotating platform, it can operate on all main pump seals and main bolt holes. The robotic arm, mounted on the simulator, measures φ2450mm × 2798mm. Its operating radius is less than or equal to a 1420-pitch circle, with a positioning accuracy ≤1mm. The quick-change module has an effective load ≤10Kg, and the operating power supply voltage is 380V.

[0041] A laser reflection sensor is installed at the end of the robotic arm to scan the edge of the threaded hole multiple times, thereby confirming the position of the thread and the coaxiality of the robotic arm with the sealing surface of the main pump.

[0042] The device of this invention is easy to install, runs smoothly, is simple to operate, and has good environmental adaptability. This inspection and maintenance device utilizes a robotic arm to carry each functional module, rotating 360° along the main pump sealing surface. It can cover all main bolt thread holes and sealing surfaces in one go, completing all inspection work in a single installation, saving equipment installation time, improving inspection and maintenance efficiency, and exhibiting good operability. The rotating platform enables highly automated operation, which helps reduce operational difficulty and minimizes radiation exposure for workers. The platform has a high degree of integration; each functional module can be disassembled, stored, and maintained individually, or stored as a single unit, occupying minimal space in the nuclear facility building.

Claims

1. An automatic maintenance device for the main sealing pair and main bolts of a nuclear power plant main cooling pump, characterized in that: The system includes a frame base and a robotic arm. The frame base comprises a lower fixed platform and an upper rotating platform, both with an outer shielding shell. The lower fixed platform has a shielding grid inside, and the upper rotating platform is fitted with a slewing bearing. The upper rotating platform is equipped with a main bolt hole cleaning module, a main bolt hole drying module, a main bolt hole polishing module, a main bolt hole oiling module, a flange surface cleaning module, a main bolt hole inspection module, a sealing surface inspection module, a rotating motor, and a sealing surface cleaning module, either via support blocks or bolts. The upper rotating platform is connected to the shielding device via the slewing bearing. The robotic arm has a force sensor and a quick-change module at its end. The quick-change module picks up the main bolt hole cleaning module, main bolt hole drying module, main bolt hole polishing module, main bolt hole oiling module, flange surface cleaning module, main bolt hole inspection module, rotating motor, and sealing surface cleaning module, thus achieving the functions of cleaning, drying, inspecting, polishing, applying anti-seize agent, and cleaning the sealing surface of the main bolt holes.

2. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The main bolt hole cleaning module includes a first quick-change fixture, a first rotary motor, a first cleaning brush, a waste liquid suction pipe, a cleaning liquid supply pipe, and a first fixed base. The lower part of the first quick-change fixture is connected to the first fixed base with a hollow structure. The first rotary motor is installed inside the first fixed base. Two first cleaning brushes are symmetrically connected to the rotating shaft of the first rotary motor. The waste liquid suction pipe and the cleaning liquid supply pipe are also installed inside the first fixed base. The first cleaning brush is driven to rotate by the first rotary motor. The first cleaning brush rotates circumferentially around the threaded surface to achieve cleaning of the entire threaded surface.

3. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The main bolt hole drying module includes a second quick-change fixture, a second fixed base, and a hot air gun. The two ends of the second fixed base are respectively connected to the second quick-change fixture and the hot air gun. The hot air gun realizes the heating and blowing action through the electrical contact of the mounting contacts of the second quick-change fixture.

4. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The main bolt hole inspection module includes a third quick-change fixture, a camera, and a prism. The camera is connected to the third quick-change fixture, and the prism is located below the camera. During inspection, the prism is inserted into the threaded hole and rotates around the thread wall to export the thread image, which is then captured by the camera.

5. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The main bolt hole polishing module includes a fourth quick-change fixture, a second rotary motor, a second cleaning brush, a negative pressure suction pipe, and a third fixed base. The fourth quick-change fixture is connected to the hollow third fixed base. The second rotary motor is housed inside the third fixed base. Two second cleaning brushes are connected to the shaft of the second rotary motor. The negative pressure suction pipe is also connected inside the third fixed base.

6. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The main bolt hole oiling module includes a fifth quick-change fixture, a third rotary motor, felt wheels, an oil storage pipe, and a fourth fixed seat. The fifth quick-change fixture is connected to the hollow fourth fixed seat, and the third rotary motor is housed inside the fourth fixed seat. Two felt wheels are connected to the shaft of the third rotary motor, and the oil storage pipe is also connected to the fourth fixed seat. The felt wheels rotate around the threaded wall, and the oil squeezed out by the oil storage pipe is brushed onto the bolt hole wall by the felt wheels.

7. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The sealing surface cleaning module includes a sixth quick-change fixture, a fourth rotary motor, a cleaning wheel, a belt drive, and a fifth fixed base. The sixth quick-change fixture is connected to the fifth fixed base with a frame structure. The fourth rotary motor is installed inside the fifth fixed base. The rotating shaft of the fourth rotary motor drives the cleaning wheel through the belt drive. The fourth rotary motor drives the cleaning wheel to rotate and the turntable to rotate, which in turn moves the sealing surface cleaning module on the sealing surface to clean the sealing surface.

8. The automatic maintenance device for the main sealing pair and main bolts of the nuclear power plant main cooling pump as described in claim 1, characterized in that: The sealing surface inspection module includes a sixth fixed base, a line array camera, and a light source. The lower part of the sixth fixed base is connected to two line array cameras via a mounting bracket, and the light source is connected to the sixth fixed base via a mounting bracket. The light source is located between the two line array cameras. The line array camera detects damage and scratches on the sealing surface of the main pump.

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