Flexible lance for flushing a secondary side tube sheet of a nuclear power plant steam generator

Abstract

The application relates to a steam generator secondary side tube plate flushing flexible spray gun, which comprises a track assembly (3), a guide assembly (2) and a flexible spray gun (1); the track assembly (3) is installed between a 0-degree hand hole (9) and a 180-degree hand hole (91) of a steam generator, the guide assembly (2) is slidingly installed on the track assembly (3); the guide assembly (2) is loaded with the flexible spray gun (1), and the flexible spray gun (1) can move back and forth in the guide assembly (2). The steam generator secondary side tube plate flushing flexible spray gun of the application can stretch the flexible spray gun nozzle into the steam generator secondary side tube plate, and can perform close-range flushing on the hard or semi-hard sludge on the steam generator secondary side tube plate, so that the flushing effect and the flushing efficiency of the steam generator secondary side tube plate are improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant steam generator maintenance technology, and in particular to a flexible spray gun for flushing the secondary side tube sheet of a nuclear power plant steam generator. Background Technology

[0002] As a crucial piece of equipment in a nuclear power plant, the steam generator's primary function is as a heat exchanger. It transfers heat from the primary coolant in the reactor's primary loop to the secondary feedwater, producing saturated steam to drive the turbine and generate electricity. During operation, fouling gradually accumulates on the tube sheet, support plate, and heat transfer tubes at the bottom of the steam generator. This fouling not only reduces the heat transfer coefficient of the tubes, leading to unstable secondary water levels and pressure drops, but also causes corrosion and even leaks in the tubes, resulting in radioactive contamination of the secondary loop. Therefore, the secondary tube sheet of the steam generator must be flushed during each refueling cycle. Efficiently cleaning this fouling is essential for ensuring the long-term stable operation of the nuclear power plant.

[0003] Cleaning the secondary side tube sheet of a steam generator typically involves placing a spray gun in the central tube rack and injecting a high-pressure water jet into the space between the heat transfer tubes for long-distance rinsing. However, this method suffers from a significant decrease in the impact force of the high-pressure water jet as the spray distance increases, making it difficult to remove hard or partially hard sludge from the tube sheet. Therefore, a flexible cleaning spray gun is needed, with the nozzle extending deep into the space between the heat transfer tubes of the steam generator for close-range rinsing of hard or partially hard sludge on the secondary side tube sheet, thus improving the rinsing effect and efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a flexible spray gun for rinsing the secondary side tube sheet of a steam generator. The flexible spray gun nozzle is inserted into the space between the secondary side tube sheets of the steam generator to perform close-range rinsing of hard or semi-hard sludge on the secondary side tube sheet, thereby improving the rinsing effect and efficiency of the secondary side tube sheet of the steam generator.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A flexible spray gun for flushing the secondary tube sheet of a steam generator includes a track assembly, a guide assembly, and a flexible spray gun. The track assembly is installed between the 0° and 180° manholes of the steam generator. The guide assembly is installed on the track assembly and can move back and forth along the track assembly between the 0° and 180° manholes of the steam generator. The guide assembly carries the flexible spray gun, which can move back and forth inside the guide assembly. By sliding back and forth on the track assembly, the guide assembly drives the flexible spray gun to a designated position between the secondary tube sheets of the steam generator. By moving back and forth inside the guide assembly, the flexible spray gun can be inserted into any position between the secondary tube sheets of the steam generator.

[0007] Furthermore, the flexible spray gun includes a spray gun handle and a high-pressure water interface installed inside the guide assembly, a flexible metal strip and a spray gun nozzle installed outside the guide assembly, and a high-pressure water source; the spray gun handle is sequentially connected to the flexible metal strip and the spray gun nozzle; the high-pressure water interface is inside the spray gun handle and extends out of the spray gun handle away from the flexible metal strip; a capillary tube is provided inside the spray gun handle, and a nozzle is provided on the spray gun nozzle; one end of the capillary tube is connected to the high-pressure water interface, and the other end extends out of the spray gun handle, passes through the flexible metal strip, and is inserted into the spray gun nozzle to communicate with the nozzle; the high-pressure water source is connected to the capillary tube through the high-pressure water interface, and the capillary tube is clamped inside the flexible metal strip. High-pressure water in the high-pressure water source enters the capillary tube through the high-pressure water interface, and then is sprayed out through the nozzle to achieve the washing of hard or semi-hard sludge on the secondary side tube plate of the steam generator.

[0008] Furthermore, the high-pressure water source is threadedly connected to the high-pressure water interface.

[0009] Furthermore, the spray gun nozzle has a capillary mounting groove inside, which is connected to the interior of the flexible metal flat strip; the capillary is installed in the capillary mounting groove, with one end connected to the nozzle on the spray gun nozzle and the other end passing through the flexible metal flat strip and connected to the high-pressure water interface.

[0010] Furthermore, the flexible spray gun has multiple capillary tubes arranged in parallel and symmetrically inside, and multiple nozzles are symmetrically arranged vertically on the spray gun head. The spray gun head has multiple capillary tube mounting slots inside, and the number of capillary tubes, nozzles, and capillary tube mounting slots are matched one-to-one. Each capillary tube mounting slot is connected to the interior of the flexible metal flat strip. One end of a capillary tube is connected to a high-pressure water interface, and the other end extends out of the spray gun handle, passes through the flexible metal flat strip, and is installed in a capillary tube mounting slot in the spray gun head and connected to a nozzle. This ensures that the flexible spray gun is in a balanced state during the flushing of the secondary side tube sheet of the steam generator.

[0011] In one embodiment, the flexible spray gun has four capillary tubes arranged in parallel and symmetrically inside, and the spray gun head has four nozzles arranged symmetrically on the top and bottom, with four capillary tube mounting slots inside the spray gun head.

[0012] Furthermore, the flexible spray gun also includes a camera cable interface mounted on the spray gun handle, and a camera with illumination function mounted on the spray gun nozzle; the camera probe faces outward from the spray gun nozzle and is used to observe the process of the spray gun nozzle rinsing hard or semi-hard sludge on the secondary side tube plate of the steam generator, thus visualizing the rinsing of hard or semi-hard sludge on the secondary side tube plate of the steam generator; the camera cable is installed inside the spray gun nozzle, passes through the spray gun nozzle and the flexible metal flat strip in sequence, and is connected to the outside through the camera cable interface on the spray gun handle; the camera cable is clamped inside the flexible metal flat strip.

[0013] Furthermore, a camera mounting slot is provided on the end face of the spray gun nozzle, and a camera cable mounting slot is provided inside the spray gun nozzle. The camera cable mounting slot is connected to both the camera mounting slot and the interior of the flexible metal strip. The camera is installed in the camera mounting slot with its probe facing outwards from the spray gun nozzle. The camera cable is installed in the camera cable mounting slot, with its free end extending outwards from the spray gun nozzle and passing through the flexible metal strip before connecting to the outside via the camera cable interface on the spray gun handle.

[0014] Furthermore, the flexible metal flat strip is formed by riveting a first stainless steel thin strip and a second stainless steel thin strip together. Both the first and second stainless steel thin strips are "〔"-shaped stainless steel strips. Through holes are provided on both sides of the first and second stainless steel thin strips for riveting. A gap is left between the first and second stainless steel thin strips to allow the capillary tube and camera cable to pass through. Both the first and second stainless steel thin strips have strip-shaped holes with a distance from the edges in the vertical length direction. The purpose is to increase the flexibility of the flexible metal flat strip while maintaining a certain rigidity, so that it can be bent into the heat transfer tubes of the steam generator through the guide assembly.

[0015] Furthermore, one or more cameras are installed on the spray gun nozzle, and one or more camera cable mounting slots are provided inside the spray gun nozzle. The number of camera mounting slots, the number of cameras, and the number of camera cable mounting slots are matched one-to-one. Each camera cable mounting slot is connected to the interior of a flexible metal flat strip and another camera mounting slot. Each camera is installed in a camera mounting slot with its probe facing the front of the spray gun nozzle. Each camera cable is installed in a camera cable mounting slot, with its free end extending out of the spray gun nozzle, passing through the flexible metal flat strip, and then connecting to the outside through a cable interface on the spray gun handle.

[0016] Furthermore, the guide assembly includes a guide straight pipe section, a guide elbow, a suspension trolley, and a 0° handhole mounting bracket; the 0° handhole mounting bracket is provided with a through second square hole rotating shaft; one end of the guide straight pipe section is connected to the guide elbow, and the other end passes through the inside of the second square hole rotating shaft and extends out of the outside of the second square hole rotating shaft;

[0017] The suspended trolley is mounted on the track assembly and can slide on the track assembly; the lower end of the suspended trolley is connected to the guide straight pipe section through the first square hole rotating shaft; the lower end of the 0° handhole mounting bracket passes through the 0° handhole of the steam generator and is fixed to the track assembly;

[0018] The guide elbow extends outside the 0° handhole mounting bracket; the flexible spray gun is installed inside the guide elbow and the guide straight pipe section, and the flexible metal flat strip extends outside the guide elbow and the guide straight pipe section;

[0019] By pushing and pulling the guide straight pipe section on the 0° handhole mounting bracket, the suspension trolley is driven to move back and forth along the central pipe gallery of the steam generator, thereby driving the flexible spray gun to move back and forth along the central pipe gallery of the steam generator.

[0020] Once the guide elbow outlet is aligned with the secondary side of the steam generator where the tube sheet needs to be flushed, manually push the flexible spray gun into the interior of the secondary side tube sheet of the steam generator; by rotating the guide straight pipe section, drive the nozzle of the flexible spray gun to pitch, and adjust the distance between the nozzle of the flexible spray gun and the secondary side tube sheet of the steam generator.

[0021] Furthermore, the guide elbow is determined according to the arrangement of the secondary side tube sheet of the steam generator, and the bending angle of the guide elbow is between 0° and 90°.

[0022] Furthermore, the track assembly includes a wire rope, a support mechanism, a tensioning mechanism, and a fixed pulley; the support mechanism includes a second support mechanism installed on the 0° handhole of the steam generator and a first support mechanism installed on the 180° handhole of the steam generator;

[0023] The first support mechanism includes a first handhole connecting plate installed on the 180° handhole of the steam generator, a first support rod connected to the first handhole connecting plate, and a first fixing plate connected to the first support rod; both the first handhole connecting plate and the first fixing plate are provided with holes for steel wire ropes to pass through.

[0024] The second support mechanism includes a second handhole connecting plate installed on the 0° handhole of the steam generator, a second support rod connected to the second handhole connecting plate, and a second fixing plate connected to the second support rod; the second handhole connecting plate is provided with holes for the steel wire rope and the 0° handhole mounting bracket to pass through; the second fixing plate is provided with holes for the steel wire rope and the guide straight pipe section to pass through;

[0025] The lower end of the 0° handhole mounting bracket passes through the 0° handhole and the second handhole connecting plate of the steam generator and is fixed on the second handhole connecting plate. The guide straight pipe section extending out of the second square hole rotating shaft passes through the second fixing plate.

[0026] A fixed pulley is installed on the second fixed plate, and a tensioning mechanism is installed on the first fixed plate. The wire rope passes around the fixed pulley, and its two ends pass through the second fixed plate, the second handhole connecting plate, the 0° handhole of the steam generator, the central pipe gallery of the steam generator, the 180° handhole of the steam generator, the first handhole connecting plate, and the first fixed plate, and is then tensioned on the tensioning mechanism.

[0027] Furthermore, the second handhole connecting plate is connected to the 0° handhole screw of the steam generator; the second support rod is threaded to the second handhole connecting plate; the shaft seat of the fixed pulley is fixed to the second fixed plate; the first handhole connecting plate is connected to the 180° handhole screw of the steam generator; and the first support rod is threaded to the first handhole connecting plate.

[0028] Furthermore, the tensioning mechanism includes an adjusting block, two clamping buckles, two guide rods, a tensioning screw, and a thrust bearing; the two guide rods are symmetrically mounted on the first fixed plate; an adjusting block and a sliding block are installed between the two guide rods; the adjusting block is fixedly mounted on the guide rod, and the sliding block can slide along the guide rod; two clamping buckles are provided on the sliding block; the tensioning screw passes through the sliding block and is connected to the adjusting block through the thrust bearing, and the tensioning screw is threadedly connected to the sliding block; both ends of the wire rope pass through the adjusting block and the sliding block; the wire rope is pressed against the clamping buckles; by tightening the tensioning screw, the distance between the adjusting block and the sliding block is increased to achieve tensioning of the wire rope.

[0029] Beneficial technical effects of the present invention:

[0030] The flexible spray gun for flushing the secondary tube sheet of a steam generator of the present invention uses a flexible metal flat strip that has both flexibility and rigidity. It can bend and enter the space between the secondary tube sheets of the steam generator through a guide component installed on the track assembly. Then, by rotating the guide straight pipe section of the guide assembly, the flexible spray gun nozzle can be tilted at a certain angle, adjusting the distance between the flexible spray gun nozzle and the tube sheet of the secondary side of the steam generator that needs to be flushed, thereby improving the flushing effect of the secondary tube sheet of the steam generator. With the help of a camera, the flushing of sludge in the tube sheet of the steam generator can be visualized, thereby improving the flushing efficiency of the sludge in the tube sheet of the steam generator. Attached Figure Description

[0031] Figure 1 A 3D view of the installation of the flexible spray gun for flushing the secondary side tube sheet of the steam generator;

[0032] Figure 2 Top view of the installation of the flexible spray gun for flushing the secondary side tube sheet of the steam generator;

[0033] Figure 3 Schematic diagram of flexible spray gun installation;

[0034] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0035] Figure 5 This is a schematic diagram of a flexible spray gun structure;

[0036] Figure 6 This is a schematic diagram of the internal structure of a flexible spray gun;

[0037] Figure 7 for Figure 2 Enlarged diagram at point X;

[0038] Figure 8 for Figure 2 Enlarged view of point XII;

[0039] Figure 9 A schematic diagram showing the installation of the second support frame, wire rope, and fixed pulley;

[0040] Figure 10 A schematic diagram showing the installation of the first support frame, wire rope, and tensioning mechanism;

[0041] In the diagram, 1. Flexible spray gun; 2. Guide assembly; 3. Track assembly; 6. Fixed pulley; 7. Secondary side tube sheet of steam generator; 8. Secondary side heat transfer tube of steam generator; 9. 0° hand hole of steam generator; 91. 180° hand hole of steam generator; 10. High-pressure water interface; 11. Spray gun handle; 12. Camera cable interface; 13. Flexible metal flat strip; 14. Riveting through hole; 15. Spray gun nozzle; 16. Nozzle; 161. Camera mounting slot; 17. Capillary tube; 170. Capillary tube mounting slot; 171. First stainless steel sheet; 172. Second stainless steel sheet; 18. Camera cable; 181. Camera... 19. Camera cable mounting slot; 20. Strip hole; 21. Guide elbow; 22. Guide straight pipe section; 23. Suspension trolley; 24. First square hole rotating shaft; 35. First support mechanism; 36. First hand hole connecting plate; 37. First support rod; 38. First fixing plate; 39. Adjusting block; 30. Clamping buckle; 30. Sliding block; 31. Guide rod; 32. Tensioning screw; 33. Steel wire rope; 44. Thrust bearing; 45. Second support mechanism; 46. Second hand hole connecting plate; 47. Second support rod; 48. Second fixing plate; 49. Second square hole rotating shaft; 40. 0° hand hole mounting bracket; 200. Camera. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the description of this invention, it should be noted that the terms "left end", "right end", "front", "rear", "external", "internal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0045] See Figure 7 This embodiment provides a flexible spray gun for flushing the secondary tube sheet of a steam generator, including a track assembly 3, a guide assembly 2, and a flexible spray gun 1. The track assembly 3 is installed between the 0° manhole 9 and the 180° manhole 91 of the steam generator. The guide assembly 2 is installed on the track assembly 3 and can move back and forth along the track assembly 3 between the 0° manhole 9 and the 180° manhole 91 of the steam generator. The guide assembly 2 carries the flexible spray gun 1, which can move back and forth inside the guide assembly 2. By sliding the guide assembly 2 back and forth on the track assembly 3, the flexible spray gun 1 is driven to a designated position between the secondary tube sheets of the steam generator. By moving the flexible spray gun 1 back and forth inside the guide assembly 2, it can be inserted into any position between the secondary tube sheets of the steam generator.

[0046] See Figure 5In this embodiment, the flexible spray gun 1 includes a spray gun handle 11 and a high-pressure water interface 10 installed inside the guide assembly 2, a flexible metal flat strip 13 and a spray gun nozzle 15 installed outside the guide assembly 2, and a high-pressure water source; the spray gun handle 11 is sequentially connected to the flexible metal flat strip 13 and the spray gun nozzle 15; the high-pressure water interface 10 is inside the spray gun handle 11 and extends out of the spray gun handle 11 away from the flexible metal flat strip 13; a capillary tube 17 is provided inside the spray gun handle 11, and a nozzle 16 is provided on the spray gun nozzle 15; one end of the capillary tube 17 is connected to the high-pressure water interface 10, and the other end extends out of the spray gun handle 11, passes through the flexible metal flat strip 13, and is inserted into the spray gun nozzle 15 and connected to the nozzle 16; the high-pressure water source is connected to the capillary tube 17 through the high-pressure water interface 10, and the capillary tube 17 is clamped inside the flexible metal flat strip 13. High-pressure water from the high-pressure water source enters the capillary tube 17 through the high-pressure water interface 10, and then is sprayed out through the nozzle 16 to wash the hard or semi-hard sludge on the secondary side tube plate of the steam generator.

[0047] In this embodiment, the high-pressure water source is threadedly connected to the high-pressure water interface 10.

[0048] See Figure 6 In this embodiment, the spray gun nozzle 15 is provided with a capillary mounting groove 170 inside, and the capillary mounting groove 170 is connected to the interior of the flexible metal flat strip 13; the capillary 17 is installed in the capillary mounting groove 170, one end is connected to the nozzle 16 on the spray gun nozzle 15, and the other end passes through the flexible metal flat strip 13 and is connected to the high-pressure water interface 10.

[0049] In this embodiment, multiple capillary tubes 17 are arranged symmetrically in parallel inside the flexible spray gun 1, and multiple nozzles 16 are symmetrically arranged vertically on the spray gun head 15. Multiple capillary tube mounting slots 170 are provided inside the spray gun head 15. The number of capillary tubes 17, the number of nozzles 16, and the number of capillary tube mounting slots 170 are matched one-to-one. Each capillary tube mounting slot 170 is connected to the inside of the flexible metal flat strip 13. One end of a capillary tube is connected to the high-pressure water interface 10, and the other end extends out of the spray gun handle 11 and passes through the flexible metal flat strip 13 before being installed in a capillary tube mounting slot 170 of the spray gun head 15 and connected to a nozzle 16. This ensures that the flexible spray gun 1 is in a balanced state during the flushing of the secondary side tube sheet of the steam generator.

[0050] In this embodiment, four capillary tubes 17 are arranged in parallel and symmetrically inside the flexible spray gun 1, and four nozzles 16 are symmetrically arranged on the spray gun nozzle 15. Four capillary tube mounting grooves 170 are provided inside the spray gun nozzle 15.

[0051] In this embodiment, the flexible spray gun 1 further includes a camera cable interface mounted on the spray gun handle 11 and a camera 200 with illumination function mounted on the spray gun nozzle 15; the probe of the camera 200 faces outward from the spray gun nozzle 15 and is used to observe the process of the spray gun nozzle 15 rinsing the hard or semi-hard sludge on the secondary side tube plate of the steam generator, thereby realizing visualization of the rinsing of hard or semi-hard sludge on the secondary side tube plate of the steam generator; the camera cable 18 is installed inside the spray gun nozzle 15, passes through the spray gun nozzle 15 and the flexible metal flat strip 13 in sequence, and is connected to the outside through the camera cable interface on the spray gun handle 11; the camera cable 18 is clamped inside the flexible metal flat strip 13.

[0052] See Figure 5-6 In this embodiment, a camera mounting slot 161 is provided on the end face of the spray gun nozzle 15, and a camera cable mounting slot is provided inside the spray gun nozzle 15. The camera cable mounting slot 181 is connected to the camera mounting slot 161 and the flexible metal flat strip 13 respectively. The camera 200 is installed in the camera mounting slot 161, with the probe facing outward from the spray gun nozzle 15. The camera cable 18 is installed in the camera cable mounting slot 181, with its free end extending outward from the spray gun nozzle 15 and passing through the flexible metal flat strip 13 before connecting to the outside through the camera cable interface on the spray gun handle 11.

[0053] See Figure 5 In this embodiment, the flexible metal flat strip 13 is formed by riveting a first stainless steel thin strip 171 and a second stainless steel thin strip 172 together. Both the first stainless steel thin strip 171 and the second stainless steel thin strip 172 are "〔" shaped stainless steel strips. The two sides of the first stainless steel thin strip 171 and the second stainless steel thin strip 172 are respectively provided with through holes 14 for riveting. A gap is left between the first stainless steel thin strip 171 and the second stainless steel thin strip 172 for the capillary tube 17 and the camera cable 18 to pass through. The first stainless steel thin strip 171 and the second stainless steel thin strip 172 are both provided with strip-shaped holes 19 with a distance from the edge in the vertical length direction. The purpose is to increase the flexibility of the flexible metal flat strip 13, while keeping the flexible metal flat strip 13 with a certain rigidity. It can be bent into the heat transfer tube of the steam generator through the guide component 2.

[0054] See Figure 6In this embodiment, one or more cameras 200 are installed on the spray gun nozzle 15, and one or more camera cable mounting slots 181 are provided inside the spray gun nozzle 15. The number of camera mounting slots 161, the number of cameras 200, and the number of camera cable mounting slots 181 are matched one-to-one. One camera cable mounting slot 181 is connected to the inside of the flexible metal flat strip 13 and one camera mounting slot 161 respectively. One camera 200 is installed in one camera mounting slot 161, with the probe facing the front of the spray gun nozzle 15. One camera cable is installed in one camera cable mounting slot 181, with the free end extending out of the spray gun nozzle 15, passing through the flexible metal flat strip 13, and then connecting to the outside through the cable interface on the spray gun handle 11.

[0055] See Figure 3-4 In this embodiment, the guide assembly 2 includes a guide straight pipe section 21, a guide elbow 20, a suspension trolley 22, and a 0° handhole mounting bracket 45; the 0° handhole mounting bracket 45 is provided with a through second square hole rotating shaft 44; one end of the guide straight pipe section 21 is connected to the guide elbow 20, and the other end passes through the inside of the second square hole rotating shaft 44 and extends out of the outside of the second square hole rotating shaft 44;

[0056] The suspension trolley 22 is mounted on the track assembly 3 and can slide on the track assembly 3; the lower end of the suspension trolley 22 is connected to the guide straight pipe section 21 through the first square hole rotating shaft 23; the lower end of the 0° handhole mounting bracket 45 passes through the 0° handhole 9 of the steam generator and is fixed on the track assembly 3.

[0057] The guide elbow 20 extends outside the 0° handhole mounting bracket 45; the flexible spray gun 1 is installed inside the guide elbow 20 and the guide straight pipe section 21, and the flexible metal flat strip 13 extends outside the guide elbow 20 and the guide straight pipe section 21.

[0058] By pushing and pulling the guide straight pipe section 21 on the 0° handhole mounting bracket 45, the suspension trolley 22 is driven to move back and forth along the central pipe gallery of the steam generator, thereby driving the flexible spray gun 1 to move back and forth along the central pipe gallery of the steam generator.

[0059] When the outlet of the guide elbow 20 is aligned with the tube sheet between the secondary side of the steam generator that needs to be flushed, manually push the flexible spray gun 1 into the tube sheet between the secondary side of the steam generator; by rotating the guide straight pipe section 21, drive the spray gun nozzle 15 of the flexible spray gun 1 to perform pitching action, and adjust the distance between the spray gun nozzle 15 of the flexible spray gun 1 and the tube sheet between the secondary side of the steam generator.

[0060] In this embodiment, the guide elbow 20 is determined according to the arrangement of the secondary side tube sheet of the steam generator, and the bending angle of the guide elbow 20 is between 0° and 90°.

[0061] See Figure 9-10The track assembly 3 includes a wire rope 38, a support mechanism, a tensioning mechanism, and a fixed pulley 6; the support mechanism includes a second support mechanism 40 installed on the 0° handhole 9 of the steam generator and a first support mechanism 30 installed on the 180° handhole 91 of the steam generator.

[0062] The first support mechanism 30 includes a first handhole connecting plate 31 installed on the 180° handhole 91 of the steam generator, a first support rod 32 connected to the first handhole connecting plate 31, and a first fixing plate 33 connected to the first support rod 32; both the first handhole connecting plate 31 and the first fixing plate 33 are provided with holes for the steel wire rope 38 to pass through.

[0063] The second support mechanism 40 includes a second handhole connecting plate 41 mounted on the 0° handhole 9 of the steam generator, a second support rod 42 connected to the second handhole connecting plate 41, and a second fixing plate 43 connected to the second support rod 42; the second handhole connecting plate 41 is provided with holes for the steel wire rope 38 and the 0° handhole mounting bracket 45 to pass through; the second fixing plate 43 is provided with holes for the steel wire rope 38 and the guide straight pipe section 21 to pass through;

[0064] The lower end of the 0° handhole mounting bracket 45 passes through the 0° handhole 9 of the steam generator and the second handhole connecting plate 41 and is fixed on the second handhole connecting plate 41. The guide straight pipe section 21 extending out of the second square hole rotating shaft 44 passes through the second fixing plate 43.

[0065] A fixed pulley 6 is installed on the second fixed plate 43, and a tensioning mechanism is installed on the first fixed plate 33. The steel wire rope 38 passes around the fixed pulley 6, and its two ends pass through the second fixed plate 43, the second hand hole connecting plate 41, the steam generator 0° hand hole 9, the steam generator central pipe gallery, the steam generator 180° hand hole 91, the first hand hole connecting plate 31, and the first fixed plate 33, and is then tensioned on the tensioning mechanism.

[0066] In this embodiment, the second handhole connecting plate 41 is screwed to the 0° handhole 9 of the steam generator; the second support rod 42 is threaded to the second handhole connecting plate 41; the shaft seat of the fixed pulley 6 is fixed on the second fixed plate 43; the first handhole connecting plate 31 is screwed to the 180° handhole 91 of the steam generator; and the first support rod 32 is threaded to the first handhole connecting plate 31.

[0067] In this embodiment, the tensioning mechanism includes an adjusting block 34, two clamping buckles 35, two guide rods 36, a tensioning screw 37, and a thrust bearing 39. The two guide rods 36 are symmetrically mounted on the first fixed plate 33. An adjusting block 34 and a sliding block 351 are installed between the two guide rods 36. The adjusting block 34 is fixedly mounted on the guide rod 36, and the sliding block 351 can slide along the guide rod 36. Two clamping buckles 35 are provided on the sliding block 351. The tensioning screw 37 passes through the sliding block 351 and is connected to the adjusting block 34 through the thrust bearing 39. The tensioning screw 37 is threadedly connected to the sliding block 351. The two ends of the wire rope 38 pass through the adjusting block 34 and the sliding block 351. The wire rope 38 is pressed against the clamping buckles 35. By tightening the tensioning screw 37, the distance between the adjusting block 34 and the sliding block 351 is increased, thereby achieving the tensioning of the wire rope 38.

[0068] See Figure 1-2 The secondary side tube sheet flushing device of the steam generator in this embodiment is used to flush the secondary side tube sheet of the steam generator, including the following steps:

[0069] Step 1: Install track assembly 3 between 0° handhole 9 and 180° handhole 91 of the steam generator, and install guide assembly 2 on track assembly 3. The guide elbow 20 of guide assembly 2 is determined according to the secondary side tube plate of the steam generator.

[0070] Step 2: Insert the flexible spray gun 1 into the guide elbow 20 and guide straight pipe section 21 of the guide assembly 2, with the flexible metal flat strip 13 extending outside the guide elbow 20 and guide straight pipe section 21.

[0071] Step 3: By pushing and pulling the guide straight pipe section 21 on the 0° handhole mounting bracket 45, the suspension trolley 22 is driven to move back and forth along the central tube gallery of the steam generator, thereby driving the flexible spray gun 1 to move back and forth along the central tube gallery of the steam generator; when the outlet of the guide elbow 20 is aligned with the tube sheet space between the secondary side of the steam generator that needs to be flushed, the flexible spray gun 1 is manually pushed into the tube sheet space between the secondary side of the steam generator.

[0072] Step 4: High-pressure water from the high-pressure water source is pumped through the high-pressure water interface 10 into the capillary tube and then sprayed out through the nozzle 16 to flush the hard or semi-hard sludge on the secondary side tube plate of the steam generator.

[0073] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A flexible spray gun for flushing the secondary side tube sheet of a steam generator, characterized in that, The system includes a track assembly (3), a guide assembly (2), and a flexible spray gun (1). The track assembly (3) is installed between the 0° handhole (9) and the 180° handhole (91) of the steam generator. The guide assembly (2) is installed on the track assembly (3) and can move back and forth on the track assembly (3) between the 0° handhole (9) and the 180° handhole (91) of the steam generator. The guide assembly (2) carries the flexible spray gun (1), which can move back and forth inside the guide assembly (2). By sliding the guide assembly (2) back and forth on the track assembly (3), the flexible spray gun (1) is driven to reach the designated secondary side tube sheet of the steam generator. By moving the flexible spray gun (1) back and forth inside the guide assembly (2), it can be inserted into any position between the secondary side tube sheets of the steam generator. The guide assembly (2) includes a guide straight pipe section (21), a guide elbow (20), a suspension trolley (22), and a 0° handhole mounting bracket (45); the suspension trolley (22) is mounted on the track assembly (3) and can slide on the track assembly (3); the lower end of the suspension trolley (22) is connected to the guide straight pipe section (21) through a first square hole rotating shaft (23); the lower end of the 0° handhole mounting bracket (45) passes through the 0° handhole (9) of the steam generator and is fixed on the track assembly (3); The track assembly (3) includes a wire rope (38), a support mechanism, a tensioning mechanism, and a fixed pulley (6); the support mechanism includes a second support mechanism (40) installed on the 0° handhole (9) of the steam generator and a first support mechanism (30) installed on the 180° handhole (91) of the steam generator; The first support mechanism (30) includes a first handhole connecting plate (31) installed on the 180° handhole (91) of the steam generator, a first support rod (32) connected to the first handhole connecting plate (31), and a first fixing plate (33) connected to the first support rod (32); both the first handhole connecting plate (31) and the first fixing plate (33) are provided with holes for the steel wire rope (38) to pass through; The second support mechanism (40) includes a second handhole connecting plate (41) installed on the 0° handhole (9) of the steam generator, a second support rod (42) connected to the second handhole connecting plate (41), and a second fixing plate (43) connected to the second support rod (42); the second handhole connecting plate (41) is provided with holes for the steel wire rope (38) and the 0° handhole mounting bracket (45) to pass through; the second fixing plate (43) is provided with holes for the steel wire rope (38) and the guide straight pipe section (21) to pass through; The lower end of the 0° handhole mounting bracket (45) passes through the 0° handhole (9) of the steam generator and the second handhole connecting plate (41) and is fixed on the second handhole connecting plate (41). The guide straight pipe section (21) extending out of the second square hole rotating shaft (44) passes through the second fixing plate (43). A fixed pulley (6) is installed on the second fixed plate (43), and a tensioning mechanism is installed on the first fixed plate (33). The wire rope (38) passes around the fixed pulley (6), and its two ends pass through the second fixed plate (43), the second handhole connecting plate (41), the 0° handhole (9) of the steam generator, the central pipe gallery of the steam generator, the 180° handhole (91) of the steam generator, the first handhole connecting plate (31) and the first fixed plate (33) respectively, and is then tensioned on the tensioning mechanism.

2. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 1, characterized in that, The flexible spray gun (1) includes a spray gun handle (11) and a high-pressure water interface (10) installed inside the guide assembly (2), a flexible metal flat strip (13) and a spray gun nozzle (15) installed outside the guide assembly (2), and a high-pressure water source; the spray gun handle (11) is sequentially connected to the flexible metal flat strip (13) and the spray gun nozzle (15); the high-pressure water interface (10) is inside the spray gun handle (11) and extends out of the spray gun handle (11) away from the flexible metal flat strip (13); The spray gun handle (11) is provided with a capillary tube (17), and the spray gun nozzle (15) is provided with a nozzle (16); one end of the capillary tube (17) is connected to the high-pressure water interface (10), and the other end extends out of the spray gun handle (11), passes through the flexible metal flat strip (13), and is inserted into the spray gun nozzle (15) and connected to the nozzle (16); the high-pressure water source is connected to the capillary tube (17) through the high-pressure water interface (10), and the capillary tube (17) is clamped in the flexible metal flat strip (13).

3. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 2, characterized in that, The spray gun nozzle (15) is provided with a capillary mounting groove (170) inside, and the capillary mounting groove (170) is connected to the interior of the flexible metal flat strip (13); the capillary (17) is installed in the capillary mounting groove (170), one end of which is connected to the nozzle (16) on the spray gun nozzle (15), and the other end passes through the flexible metal flat strip (13) and is connected to the high-pressure water interface (10).

4. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 3, characterized in that, The flexible spray gun (1) has multiple capillary tubes (17) arranged in parallel and symmetrically inside. The spray gun nozzle (15) has multiple nozzles (16) arranged symmetrically on its upper and lower sides. The spray gun nozzle (15) has multiple capillary mounting slots (170) inside. The number of capillary tubes (17), the number of nozzles (16), and the number of capillary mounting slots (170) are matched one by one. Each capillary mounting slot (170) is connected to the interior of the flexible metal flat strip (13). One end of a capillary tube is connected to the high-pressure water interface (10), and the other end extends out of the spray gun handle (11) and passes through the flexible metal flat strip (13) before being installed in a capillary mounting slot (170) of the spray gun nozzle (15) and connected to a nozzle (16). This ensures that the flexible spray gun (1) is in a balanced state during the flushing of the secondary side tube sheet of the steam generator.

5. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 2, characterized in that, The flexible spray gun (1) also includes a camera cable interface installed on the spray gun handle (11) and a camera (200) with lighting function installed on the spray gun nozzle (15); the probe of the camera (200) faces outward from the spray gun nozzle (15); the camera cable (18) is installed inside the spray gun nozzle (15), passes through the spray gun nozzle (15) and the flexible metal flat strip (13) in sequence, and is connected to the outside through the camera cable interface on the spray gun handle (11); the camera cable (18) is clamped in the flexible metal flat strip (13).

6. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 5, characterized in that, A camera mounting slot (161) is provided on the end face of the spray gun nozzle (15), and a camera cable mounting slot (181) is provided inside the spray gun nozzle (15). The camera cable mounting slot (181) is connected to the camera mounting slot (161) and the flexible metal flat strip (13) respectively. The camera (200) is installed in the camera mounting slot (161), with the probe facing out of the spray gun nozzle (15). The camera cable (18) is installed in the camera cable mounting slot (181), with its free end extending out of the spray gun nozzle (15) and passing through the flexible metal flat strip (13) before connecting to the outside through the camera cable interface on the spray gun handle (11).

7. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 5, characterized in that, The flexible metal flat strip (13) is formed by riveting together a first stainless steel strip (171) and a second stainless steel strip (172). Both the first stainless steel strip (171) and the second stainless steel strip (172) are "〔" shaped stainless steel strips. The two sides of the first stainless steel strip (171) and the second stainless steel strip (172) are respectively provided with through holes (14) for riveting. A gap is left between the first stainless steel strip (171) and the second stainless steel strip (172) for the capillary tube (17) and the camera cable (18) to pass through. Both the first stainless steel strip (171) and the second stainless steel strip (172) have strip-shaped holes (19) with a distance from the edge in the vertical length direction.

8. The flexible spray gun for flushing the secondary side tube sheet of the steam generator according to claim 1, characterized in that, The 0° handhole mounting bracket (45) is provided with a through second square hole rotating shaft (44); one end of the guide straight pipe section (21) is connected to the guide elbow (20), and the other end passes through the inside of the second square hole rotating shaft (44) and extends out of the outside of the second square hole rotating shaft (44); The guide elbow (20) extends outside the 0° handhole mounting bracket (45); the flexible spray gun (1) is installed inside the guide elbow (20) and the guide straight pipe section (21), and the flexible metal flat strip (13) extends outside the guide elbow (20) and the guide straight pipe section (21); By pushing and pulling the guide straight pipe section (21) on the 0° handhole mounting bracket (45), the suspension trolley (22) is driven to move back and forth along the central pipe gallery of the steam generator, thereby driving the flexible spray gun (1) to move back and forth along the central pipe gallery of the steam generator. When the outlet of the guide elbow (20) is aligned with the tube sheet between the secondary side of the steam generator that needs to be flushed, manually push the flexible spray gun (1) into the tube sheet between the secondary side of the steam generator; by rotating the guide straight pipe section (21), drive the spray gun nozzle (15) of the flexible spray gun (1) to perform pitching action, and adjust the distance between the spray gun nozzle (15) of the flexible spray gun (1) and the tube sheet between the secondary side of the steam generator.

9. The flexible spray gun for flushing the secondary side tube sheet of a steam generator according to claim 8, characterized in that, The tensioning mechanism includes an adjusting block (34), two clamping buckles (35), two guide rods (36), a tensioning screw (37), and a thrust bearing (39); the two guide rods (36) are symmetrically mounted on the first fixed plate (33); the adjusting block (34) and the sliding block (351) are installed between the two guide rods (36); the adjusting block (34) is fixedly mounted on the guide rods (36), and the sliding block (351) can slide along the guide rods (36); two clamping buckles are provided on the sliding block (351). 35); The tensioning screw (37) passes through the sliding block (351) and is connected to the adjusting block (34) through the thrust bearing (39). The tensioning screw (37) and the sliding block (351) are threaded together. The two ends of the wire rope (38) pass through the adjusting block (34) and the sliding block (351). The wire rope (38) is pressed against the clamping buckle (35). The tensioning of the wire rope (38) is achieved by increasing the distance between the adjusting block (34) and the sliding block (351) by tightening the tensioning screw (37).

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