Device and method for cleaning inner wall of small-diameter tube holes in nuclear power evaporator

Abstract

The present invention discloses an inner wall cleaning device and method for small-diameter pipe holes in a nuclear power evaporator. In the device, a scouring pad is penetrated and fixed by a hand drill bolt, and two pressing blocks are provided to further compress and fix the scouring pad, so that the scouring pad and the hand drill bolt are fixed as one. The hand drill bolt and the connecting rod are then fixed by a connecting pipe, and an anti-collision block is added to the connecting rod, so that the device can be extended into the small-diameter pipe hole to be cleaned under the drive of a hand electric drill to perform a cleaning operation, and can ensure that the small-diameter pipe hole will not be scratched while eliminating rust spots. The device has the characteristics of simple structure, convenient operation, high safety, low manufacturing cost and strong versatility, and greatly improves the cleaning efficiency and product quality.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power equipment manufacturing, in particular to a cleaning and care technology for small-diameter tube holes on an evaporator, and specifically to an inner wall cleaning device and method for small-diameter tube holes in a nuclear power evaporator. Background Art

[0002] The tube sheet components of the evaporator in the current nuclear power project are made of 16MND5 or 18MND5 materials, and the tube sheet contains 8000-20000 tube holes, and the inner diameter of these tube holes ranges from Φ15mm to Φ23mm. Although the evaporator tube sheet components are cleaned and protected after the tube hole processing stage, they are limited by the manufacturing process, manufacturing cycle and air humidity of the nuclear power project. The inner wall of the tube hole that is static for a long time gradually produces an oxidation reaction with the air. As time goes by, the thin floating rust on the inner wall of the tube hole will gradually turn into rust spots and firmly adhere to the inner wall of the tube hole.

[0003] Before using the tube sheet assembly of the evaporator, all the tube holes need to be thoroughly cleaned and the cleaning requirements should be met, such as no discoloration after wiping and no rust spots after visual inspection. According to the previous cleaning methods, the tube holes are cleaned by wiping with non-woven fabric or grinding with graphite ball head.

[0004] The non-woven fabric wiping method needs to be used in conjunction with acetone, and should be performed when the floating rust on the inner wall of the pipe hole has just formed. When wiping, insert the non-woven fabric into the pipe hole and clean it repeatedly until the floating rust is removed. Since propanol is a toxic and harmful chemical, long-term use will cause dizziness, nausea, and fatigue to the human body. The operator must wear a gas mask and protective gloves during use, which causes great inconvenience to the operator during the cleaning process of the pipe hole, thereby increasing the cleaning time.

[0005] Graphite ball head grinding is often used for stubborn rust or impurities on the inner wall of pipe holes. When in use, the graphite ball head, extension rod and hand drill are connected in sequence, and the graphite ball head is driven by the hand drill to rotate at high speed to remove the stubborn rust on the pipe wall; but due to the material of the graphite ball head, it is easy to cause scratches or size deviations on the pipe hole when removing rust, which causes the size re-inspection of the inner diameter of the pipe hole, greatly prolonging the cleaning cycle.

[0006] In summary, under the premise of ensuring the quality of the evaporator tube sheet assembly, maximizing the efficiency of tube hole cleaning, avoiding damage to the tube wall during the cleaning process, and reducing the physical harm of hazardous chemicals to operators have become urgent issues to be solved in the nuclear power manufacturing process. Summary of the invention

[0007] In order to overcome the above problems, the inventors have conducted intensive research and designed a device and method for cleaning the inner wall of small-diameter pipe holes in nuclear power evaporators. In the device, a scouring pad is penetrated and fixed by a hand drill bolt, and two pressure blocks are provided to further compress and fix the scouring pad, so that the scouring pad and the hand drill bolt are fixed as one, and then the hand drill bolt and the connecting rod are fixed by a connecting pipe, and an anti-collision block is added to the connecting rod, so that the device can be driven by a hand electric drill to extend into the small-diameter pipe hole to be cleaned for cleaning operations, and can eliminate rust spots while ensuring that the small-diameter pipe hole will not be scratched. It has the characteristics of simple structure, easy operation, high safety, low manufacturing cost and strong versatility, which greatly improves the cleaning efficiency and product quality, thereby completing the present invention.

[0008] Specifically, the purpose of the present invention is to provide a device for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator.

[0009] The device comprises a hand drill bolt 1, a scouring pad 3 and a connecting rod 6;

[0010] The scouring pad 3 and the connecting rod 6 are fixed together by the hand drill bolt 1, so that the scouring pad 3 can be inserted into the small-diameter tube hole to clean the inner wall thereof.

[0011] The device further comprises a pressing block 2 located on one side of the scouring pad 3 and a pressing block 2 4 located on the other side of the scouring pad 3, and the hand drill bolt 1 passes through the pressing block 2, the scouring pad 3 and the pressing block 2 4 in sequence;

[0012] The scouring pad 3 is squeezed and fixed by the pressing block 1 2 and the pressing block 2 4 to prevent the scouring pad 3 from moving during the cleaning process.

[0013] The pressing block 2 includes an integrated large end cylinder 21 and a small end cylinder 22.

[0014] A through hole is provided on the pressing block 1 2 for the hand drill bolt 1 to pass through.

[0015] A through hole is provided on the pressing block 4 for the hand drill bolt 1 to pass through.

[0016] A groove 41 capable of accommodating the small end cylinder 22 is provided on the end of the pressing block 2 4 adjacent to the scouring pad 3.

[0017] The scouring pad 3 is pressed into and fixed in the groove 41 through the small end cylinder 22 .

[0018] The hand drill bolt 1 includes, from one end to the other end, a top cap 11, a bare rod portion 12, a threaded portion 13, a conical portion 14 and a drill portion 15;

[0019] The drill-shaped portion 15 is used to drill a hole in the scouring pad 3, thereby driving the conical portion 14 and the threaded portion 13 to pass through the scouring pad 3 in sequence, and finally fixing the scouring pad 3 and the pressing block 1 2 and the pressing block 2 4 on the polished rod portion 12.

[0020] The device further comprises a connecting pipe 5 and a connecting rod 6.

[0021] The conical portion 14 and the drill-shaped portion 15 are accommodated by the connecting pipe 5, and the pressure block 1 2, the scouring pad 3 and the pressure block 2 4 are clamped and fixed by the connecting pipe 5 and the top cap 11;

[0022] The connecting rod 6 and the hand drill bolt 1 are fixed by the connecting pipe 5, so that the connecting rod 6 can drive the hand drill bolt 1 and the scouring pad 3 thereon to perform cleaning operations inside the small-diameter pipe hole.

[0023] The connecting rod 6 is in the shape of a long rod, one end of which is a threaded end 61 with an external thread.

[0024] The connecting pipe 5 is cylindrical, and an internal thread matching with the threaded portion 13 is formed on the inner wall of the upper end 51 of the connecting pipe 5 , and an internal thread matching with the threaded end 61 is formed on the inner wall of the lower end 52 of the connecting pipe 5 .

[0025] The device further comprises an anti-collision block 7 sleeved on the connecting rod 6;

[0026] By fixing the anti-collision block 7 at a specific position of the connecting rod 6, it is prevented that the connecting rod 6 and the inner wall of the small-diameter pipe hole are scratched during the cleaning operation.

[0027] The anti-collision block 7 is cylindrical, and a through hole with an inner diameter substantially consistent with the outer diameter of the connecting rod 6 is provided along its axial direction.

[0028] A threaded hole 71 penetrating to the through hole is provided on the side of the anti-collision block 7 along its radial direction;

[0029] The anti-collision block 7 is fixed on the connecting rod 6 by an anti-threading screw 8 which can be screwed into the threaded hole 71 .

[0030] The present invention also provides a method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator.

[0031] The method is realized by the inner wall cleaning device of the small-diameter tube hole in the nuclear power evaporator described above;

[0032] Preferably, the method comprises the following steps:

[0033] Step 1, assembling an inner wall cleaning device for small-diameter tube holes in a nuclear power evaporator;

[0034] Step 2, after connecting the connecting rod 6 to the hand drill, insert the inner wall cleaning device into the small-diameter pipe hole, and control the scouring pad 3 on the inner wall cleaning device to reciprocate at least once along the length direction of the small-diameter pipe hole;

[0035] Step 3, clean the small-diameter tube holes one by one, and replace the scouring pad 3 regularly.

[0036] Wherein, the step 1 includes the following sub-steps:

[0037] Sub-step 1, set the pressing block 2 on the hand drill bolt 1, and make the large end cylinder 21 abut against the top cap 11;

[0038] Sub-step 2, controlling the hand drill bolt 1 to rotate and penetrate the scouring pad 3;

[0039] Sub-step 3, sleeve the second pressing block 4 onto the hand drill bolt 1;

[0040] Sub-step 4, screwing the connecting tube 5 onto the threaded portion 13, and pressing the pressing block 2 4 through the connecting tube 5, so that the small end cylinder 22 and the scouring pad 3 are pressed into the groove 41;

[0041] Sub-step 5, screwing the connecting rod 6 onto the connecting pipe 5;

[0042] Sub-step 6, fixing the anti-collision block 7 on the connecting rod 6 through the anti-threading screw 8.

[0043] The beneficial effects of the present invention include:

[0044] (1) According to the device and method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator provided by the present invention, a scouring pad is used to clean stubborn floating rust, and the scouring pad is penetrated and fixed by a hand drill bolt, thereby ensuring that the stubborn floating rust can be completely removed and the selected scouring pad will not scratch the small-diameter tube hole;

[0045] (2) According to the device and method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator provided by the present invention, two pressing blocks are selected to further clamp and fix the scouring pad, thereby improving the firmness of the scouring pad in the axial direction of the small-diameter tube hole, thereby improving the cleaning effect;

[0046] (3) According to the device and method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator provided by the present invention, the device can be used in conjunction with a hand-held electric drill, and the hand-held electric drill is used to provide rotation, and then the device is manually controlled to move up and down in the small-diameter tube hole, so that a small-diameter tube hole can be cleaned quickly and conveniently, which is particularly suitable for working conditions where a large number of tube holes need to be cleaned;

[0047] (4) The inner wall cleaning device for small-diameter tube holes in nuclear power evaporators provided by the present invention has a simple structure, is easy to operate, has strong versatility, and is suitable for large-scale production. Hand-drilled bolts, connecting pipes, and connecting rods can all be processed and manufactured using waste heat exchange tubes, and the production cost is low.

[0048] (5) The method for cleaning the inner wall of small-diameter tube holes in nuclear power evaporators provided by the present invention greatly shortens the cleaning cycle of the inner wall of small-diameter tube holes, avoids scratches on the tube walls, and greatly improves product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram showing the overall structure of an inner wall cleaning device for a small-diameter tube hole in a nuclear power evaporator in a preferred embodiment of the present application is shown;

[0050] Figure 2 An exploded view of an inner wall cleaning device for a small-diameter tube hole in a nuclear power evaporator in a preferred embodiment of the present application is shown;

[0051] Figure 3 A schematic diagram showing the structure of a hand drill bolt in a preferred embodiment of the present application is shown;

[0052] Figure 4 A schematic diagram showing the structure of a pressing block 1 in a preferred embodiment of the present application is shown;

[0053] Figure 5 A schematic diagram showing the structure of a pressing block 2 in a preferred embodiment of the present application is shown;

[0054] Figure 6 A schematic diagram showing the structure of a connecting pipe in a preferred embodiment of the present application is shown;

[0055] Figure 7 A schematic structural diagram of a connecting rod in a preferred embodiment of the present application is shown;

[0056] Figure 8 A schematic diagram showing the structure of an anti-collision block in a preferred embodiment of the present application is shown;

[0057] Fig. 9 A schematic diagram of the structure of the anti-threading top wire in a preferred embodiment of the present application is shown;

[0058] Fig.10 A schematic structural diagram of a nuclear power evaporator tube plate to be cleaned in the present application is shown.

[0059] Reference numerals

[0060] 1-Hand drill bolt

[0061] 11-Top Hat

[0062] 12- Bare Rod

[0063] 13-Threaded part

[0064] 14-cone

[0065] 15-Drill

[0066] 2-Block one

[0067] 21-Big end cylinder

[0068] 22- small end cylinder

[0069] 3- Scouring pad

[0070] 4-Block II

[0071] 41-Groove

[0072] 5-Connecting pipe

[0073] 51-Top

[0074] 52-lower end

[0075] 6-Connecting rod

[0076] 61-Threaded end

[0077] 7- Anti-collision block

[0078] 71-Threaded hole

[0079] 8- Anti-threading

[0080] 9-Nuclear power evaporator tube sheet DETAILED DESCRIPTION

[0081] The present invention will be further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present invention will become more clear and distinct.

[0082] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0083] According to the present invention, a device for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator is provided. Figure 1 and Figure 2 As shown in , the device includes a hand drill bolt 1, a scouring pad 3 and a connecting rod 6;

[0084] The scouring pad 3 and the connecting rod 6 are fixed by the hand drill bolt 1, so that the device forms an integrated structure, and the scouring pad 3 can be controlled to extend into the small-diameter tube hole to clean the inner wall thereof by clamping the connecting rod 6. The connecting rod 6 can be controlled to move up and down, and can also rotate while moving up and down, thereby improving the cleaning effect and cleaning efficiency.

[0085] In a preferred embodiment, Figure 3 As shown in the figure, the hand drill bolt 1 is in a "T" shape as a whole, and is formed by integrated machining, and includes, from one end to the other end, a top cap 11, a smooth rod portion 12, a threaded portion 13, a conical portion 14 and a drill portion 15; the integrated hand drill bolt 1 can improve the installation and replacement efficiency of the scouring pad, and can moderately ensure the assembly quality near the scouring pad, just meeting the cleaning requirements of the inner wall of the pipe hole.

[0086] The drill-shaped portion 15 is used to drill a hole in the scouring pad 3, thereby driving the conical portion 14 and the threaded portion 13 to pass through the scouring pad 3 in sequence, and finally fixing the scouring pad 3 and the pressing block 1 2 and the pressing block 2 4 on the polished rod portion 12.

[0087] The top cap 11 is cylindrical, with a mesh-like side surface, a through hole with a diameter of 10 mm in the middle, and a smooth transition at the top edge; preferably, the top of the top cap 11 is a smooth curve without edges and corners.

[0088] Further preferably, the side surface texture of the top cap 11 is m0.5, so as to play an anti-slip role during use.

[0089] The polished rod portion 12 is a smooth straight rod segment, which is a semi-polished or polished surface with a roughness Ra less than 3.2; more preferably, the outer surface of the polished rod portion 12 is a polished surface with a roughness Ra less than 1.6.

[0090] The pressing block 1 2 , the scouring pad 3 and the pressing block 2 4 are all compressed and fixed on the polished rod portion 12 .

[0091] The thread of the screw part 13 is M8, the thread length is 10mm, the rod diameter is 8mm, and the rod length is 15mm.

[0092] The outer surface of the conical portion 14 is a cone-like shape; it is used for transition between the threaded portion 13 and the drill-shaped portion 15 so that the scouring pad can smoothly penetrate into the smooth rod portion 12.

[0093] Preferably, the outer surface of the conical portion 14 is smooth with a roughness Ra less than 1.6, the diameter of the large end face is the same as the rod diameter of the screw portion 13, and the top cone angle is 70-80°, which is convenient for penetrating the scouring pad and expanding the hole of the scouring pad.

[0094] The outer surface of the drill-shaped portion 15 is a twist drill structure, with a drill head diameter of 6mm, a blade length of 20mm, and a blade angle of 135° at the end. The drill-shaped portion 15 is used to drill through and install the scouring pad. The specific process is: align the drill-shaped portion 15 with the center of the scouring pad 3, directly rotate the top cap 11 or insert a wooden rod or other straight rod into the top cap 11 to increase the grip and rotation force, so that the drill-shaped portion 15 passes through the scouring pad 3, and then the hole diameter of the scouring pad 3 is enlarged through the conical portion 14 area, and smoothly passes through the screw portion 13 to enter the smooth rod portion 12, and fits with the pressing block 2.

[0095] The diameter of the shank of the drill-shaped portion 14 is the same as the diameter of the small-mouth end of the cone-shaped portion 13 .

[0096] In a preferred embodiment, the device further comprises a pressing block 2 located on one side of the scouring pad 3 and a pressing block 2 4 located on the other side of the scouring pad 3, and the hand drill bolt 1 passes through the pressing block 2, the scouring pad 3 and the pressing block 2 4 in sequence;

[0097] The scouring pad 3 is squeezed and fixed by the pressing block 1 2 and the pressing block 2 4 to prevent the scouring pad 3 from moving along the axial direction of the small-diameter tube hole during the cleaning process.

[0098] Preferably, the pressing block 2 is made of nylon, which can meet the strength requirements and ensure that the small-diameter pipe hole will not be scratched.

[0099] Preferably, the cross section of the pressing block 2 is in a convex shape, such as Figure 4 As shown in FIG. 1 , the pressing block 2 includes an integrated large end cylinder 21 and a small end cylinder 22.

[0100] A through hole is provided on the pressing block 1 2 for the hand drill bolt 1 to pass through.

[0101] A through hole is provided on the pressing block 4 for the hand drill bolt 1 to pass through.

[0102] A groove 41 capable of accommodating the small end cylinder 22 is provided on the end of the pressing block 2 4 adjacent to the scouring pad 3.

[0103] The scouring pad 3 is pressed into and fixed in the groove 41 through the small end cylinder 22 .

[0104] Specifically, the outer diameter of the large end cylinder of the pressing block 2 is larger than the outer diameter of the top cap 11 of the hand drill bolt to ensure that the top cap 11 will not hit the inner wall of the small-diameter pipe hole when the cleaning device is running at high speed.

[0105] The outer diameter of the pressing block 2 and the pressing block 4 is determined according to the inner diameter of the small-diameter tube hole to be cleaned. Preferably, the outer diameter of the pressing block 2 and the pressing block 4 is controlled within the range of 14mm-22mm to ensure that it is slightly smaller than the inner diameter of the small-diameter tube hole.

[0106] The diameter of the through hole on the pressing block 1 2 and the pressing block 2 4 is larger than the outer diameter of the polished rod portion 12. Preferably, the difference between the diameter of the through hole on the pressing block 2 and the pressing block 2 4 and the outer diameter of the polished rod portion 12 is less than 4 mm. Such a setting can facilitate the hand drill bolt 1 to pass through the pressing block, and can also reduce the range of movement of the hand drill bolt 1 in the through hole of the pressing block, so that the cleaning device as a whole is more stable and reliable.

[0107] Preferably, if Figure 5 As shown in , according to a preferred embodiment of the present invention, the second pressing block 4 is made of nylon, and the cross-section of the second pressing block 4 is in a "concave" shape. Preferably, the outer diameter of the second pressing block 4 is the same as the outer diameter of the first pressing block.

[0108] Preferably, the inner diameter of the groove 41 of the pressing block 2 4 is larger than the outer diameter of the large end cylinder 21 of the pressing block 1 2, and the difference in diameter is not less than 8 mm. In the present application, preferably, the pressing block 1 and the pressing block 2 are both made of nylon 1010 produced by Qinhuangdao Shengze Machinery Equipment Co., Ltd.

[0109] In a preferred embodiment, the scouring pad 3 is a common industrial scouring pad with a thickness of 10-15 mm, and preferably a particle size of 400# or 500#. In this application, the 3M scouring pad of Qinhuangdao Lingxin Trading Co., Ltd. is selected. The applicant has found that in order to achieve rapid cleaning of tens of thousands of tube holes, the time efficiency ratio of selecting scouring pad as the main cleaning specimen is the highest, which can meet the requirements of efficiency and precision in tube sheet processing.

[0110] In a preferred embodiment, Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown in FIG. , the device further includes a connecting pipe 5 and a connecting rod 6.

[0111] The conical portion 14 and the drill-shaped portion 15 are accommodated by the connecting pipe 5 to prevent the drill-shaped portion 15 from scratching the small-diameter pipe hole, and the pressure block 1 2, the scouring pad 3 and the pressure block 2 4 are clamped and fixed by the connecting pipe 5 and the top cap 11;

[0112] The connecting rod 6 and the hand drill bolt 1 are fixed by the connecting pipe 5, so that the connecting rod 6 can drive the hand drill bolt 1 and the scouring pad 3 thereon to perform cleaning operations inside the small-diameter pipe hole.

[0113] Preferably, the connecting rod 6 is in the shape of a long rod, one end of which is a threaded end 61 with an external thread; preferably, the connecting rod 6 can be manufactured in a length of 300mm-500mm according to the depth of the small-diameter tube hole of the evaporator tube plate assembly, and can be selected for use according to the specific hole depth.

[0114] The connecting pipe 5 is cylindrical, and an internal thread matching with the threaded portion 13 is formed on the inner wall of the upper end 51 of the connecting pipe 5 , and an internal thread matching with the threaded end 61 is formed on the inner wall of the lower end 52 of the connecting pipe 5 .

[0115] Preferably, the length of the connecting pipe 5 is 70-80 mm, more preferably 70 mm, to ensure that the overall weight of the device is reduced while meeting the requirements of use, making the entire device lighter and easier to clean in a small space.

[0116] In a preferred embodiment, Figure 1 , Figure 2 and Figure 8 As shown in , the device also includes an anti-collision block 7 sleeved on the connecting rod 6;

[0117] By fixing the anti-collision block 7 at a specific position of the connecting rod 6, it is prevented that the connecting rod 6 and the inner wall of the small-diameter pipe hole are scratched during the cleaning operation.

[0118] Preferably, the anti-collision block 7 is cylindrical, and a through hole with an inner diameter basically consistent with the outer diameter of the connecting rod 6 is opened along its axial direction to reduce the movable space of the connecting rod 6 in the through hole of the anti-collision block 7; preferably, the outer diameter of the anti-collision block 7 is the same as the outer diameter of the pressure block 1 and the pressure block 2.

[0119] Preferably, the length of the anti-collision block 7 is selected to be 100 mm, so as to ensure that when a long connecting rod 6 is used, the connecting rod 6 will not hit the inner wall of the tube hole, thereby improving the overall safety of the device.

[0120] Preferably, a threaded hole 71 penetrating to the through hole is provided on the side of the anti-collision block 7 along its radial direction;

[0121] The anti-collision block 7 is fixed on the connecting rod 6 by an anti-threading screw 8 which can be screwed into the threaded hole 71 .

[0122] Preferably in the present application, the anti-collision block 7 is made of nylon material model nylon 1010 produced by Qinhuangdao Shengze Machinery Equipment Co., Ltd.

[0123] Preferably, the anti-stringing screw 8 is an external thread structure with an internal hexagonal groove at the upper end. After the anti-collision block 7 is inserted into the connecting rod 6, the anti-stringing screw 8 is rotated by an internal hexagonal tool so that the lower end surface of the anti-stringing screw 8 is pressed against the surface of the connecting rod 6, thereby fixing the anti-collision block 7 at any position of the connecting rod 6.

[0124] Preferably, the overall height of the anti-threading screw 8 shall not be greater than the wall thickness of the anti-collision block 7 to prevent the anti-threading screw 8 from being too long and scratching the inner wall of the pipe hole.

[0125] In the present application, the coaxiality of the hand drill bolt 1, the pressure block 1 2, the scouring pad 3, the pressure block 2 4, the connecting pipe 5, the connecting rod 6, and the anti-collision block 7 are all the same.

[0126] The present application also provides a method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator, which is implemented by the inner wall cleaning device for the small-diameter tube hole in a nuclear power evaporator described above;

[0127] Preferably, the method comprises the following steps:

[0128] Step 1: Assemble the inner wall cleaning device of the small-diameter tube holes in the nuclear power evaporator. The assembly process takes 4 minutes.

[0129] Step 2, after connecting the connecting rod 6 to the electric drill, drive the inner wall cleaning device to rotate through the electric drill, insert the inner wall cleaning device into the small-diameter pipe hole, and control the scouring pad 3 on the inner wall cleaning device to move back and forth at least once along the length direction of the small-diameter pipe hole; during the reciprocating process, the rotating scouring pad can complete the cleaning operation of the inner wall of the small-diameter pipe hole. When the depth of the small-diameter pipe hole is 500mm, the cleaning operation of each small-diameter pipe hole takes 6-10 seconds.

[0130] Step 3, clean the small-diameter tube holes one by one, and replace the scouring pad 3 regularly, wherein the scouring pad is replaced every 20 minutes of continuous work, that is, the scouring pad is replaced after cleaning about 150-200 tube holes, and each replacement of the scouring pad takes 3 minutes.

[0131] Take a small nuclear power evaporator tube sheet 9 with about 2000 tube holes as an example. The nuclear power evaporator tube sheet is made of 16MND5 and its appearance structure is as follows: Fig.10 As shown in , when cleaning the tube holes on the tube sheet of the nuclear power evaporator, due to the large number of tube holes and the distance between two adjacent tube holes being less than the tube hole diameter, the traditional cleaning equipment cannot be used; the cleaning device provided by this application is selected and the above method is used to clean the tube sheet, and the cleaning work of all the tube holes is completed in less than 6 hours, and after inspection one by one, no scratches on the inner wall of the tube hole, excessive hole diameter, and visual unqualified problems are found. Based on this, for the nuclear power evaporator tube sheet with 20,000 tube holes, since the tube sheet is larger, it can allow multiple people to clean at the same time, and 5 operators are selected accordingly. The inner wall cleaning method of small-diameter tube holes in the nuclear power evaporator in this application can complete all tube hole cleaning work within 12 hours, which can meet the requirements of nuclear power equipment for cleaning time and cleaning quality.

[0132] Preferably, step 1 includes the following sub-steps:

[0133] Sub-step 1, set the pressing block 2 on the hand drill bolt 1, and make the large end cylinder 21 abut against the top cap 11;

[0134] Sub-step 2, controlling the hand drill bolt 1 to rotate and penetrate the scouring pad 3;

[0135] Sub-step 3, sleeve the second pressing block 4 onto the hand drill bolt 1;

[0136] Sub-step 4, screwing the connecting tube 5 onto the threaded portion 13, and pressing the pressing block 2 4 through the connecting tube 5, so that the small end cylinder 22 and the scouring pad 3 are pressed into the groove 41;

[0137] Sub-step 5, screwing the connecting rod 6 onto the connecting pipe 5;

[0138] Sub-step 6, fixing the anti-collision block 7 on the connecting rod 6 through the anti-threading screw 8.

[0139] In the sub-step 2, the drill-shaped portion 15 is aligned with the center of the scouring pad 3, and a straight rod is inserted into the top cap 11 to manually screw the hand drill bolt 1, so that the drill-shaped portion 15 passes through the scouring pad 3, and then the aperture of the scouring pad 3 is enlarged through the conical portion 14 area, so that the scouring pad passes through the screw portion 13 and enters the smooth rod portion 12, and fits with the pressing block 2.

[0140] The present invention has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, the present invention may be subjected to a variety of substitutions and improvements, all of which fall within the scope of protection of the present invention.

Claims

1. A device for cleaning the inner wall of small-caliber tube holes in a nuclear power evaporator, characterized in that: The device comprises a hand drill bolt (1), a scouring pad (3) and a connecting rod (6); The scouring pad (3) and the connecting rod (6) are fixed by a hand drill bolt (1), so that the scouring pad (3) can be inserted into the small-diameter tube hole to clean the inner wall thereof; The device also includes a pressing block 1 (2) located on one side of the scouring pad (3) and a pressing block 2 (4) located on the other side of the scouring pad (3), and the hand drill bolt (1) passes through the pressing block 1 (2), the scouring pad (3) and the pressing block 2 (4) in sequence; The scouring pad (3) is squeezed and fixed by pressing block 1 (2) and pressing block 2 (4) to prevent the scouring pad (3) from moving during the cleaning process; The pressing block 1 (2) comprises an integrated large end cylinder (21) and a small end cylinder (22), A through hole is provided on the pressing block (2) for the hand drill bolt (1) to pass through. A through hole is provided on the second pressing block (4) for the hand drill bolt (1) to pass through. A groove (41) capable of accommodating the small-end cylinder (22) is provided on one end of the pressing block (4) adjacent to the scouring pad (3). The scouring pad (3) is pressed into and fixed in the groove (41) through the small end cylinder (22).

2. The inner wall cleaning device for small-diameter tube holes in nuclear power evaporators according to claim 1 is characterized in that: The hand drill bolt (1) comprises, from one end to the other end, a top cap (11), a smooth rod portion (12), a threaded portion (13), a conical portion (14) and a drill portion (15); The drill-shaped portion (15) is used to drill a hole in the scouring pad (3), thereby driving the conical portion (14) and the threaded portion (13) to pass through the scouring pad (3) in sequence, and finally fixing the scouring pad (3) and the pressing block 1 (2) and the pressing block 2 (4) on the polished rod portion (12).

3. The inner wall cleaning device for small-diameter tube holes in nuclear power evaporator according to claim 2 is characterized in that: The device also includes a connecting pipe (5) and a connecting rod (6). The conical portion (14) and the drill-shaped portion (15) are accommodated by the connecting pipe (5), and the pressure block 1 (2), the scouring pad (3) and the pressure block 2 (4) are clamped and fixed by the connecting pipe (5) and the top cap (11); The connecting rod (6) and the hand drill bolt (1) are fixed by the connecting pipe (5), so that the connecting rod (6) can drive the hand drill bolt (1) and the scouring pad (3) thereon to perform cleaning operations inside the small-diameter pipe hole.

4. The inner wall cleaning device for small-diameter tube holes in nuclear power evaporators according to claim 3 is characterized in that: The connecting rod (6) is in the shape of a long rod, one end of which is a threaded end (61) with an external thread. The connecting tube (5) is cylindrical, and an internal thread matching the threaded portion (13) is provided on the inner wall of the upper end (51) of the connecting tube (5), and an internal thread matching the threaded end (61) is provided on the inner wall of the lower end (52) of the connecting tube (5).

5. A method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator, characterized in that: The method is implemented by the inner wall cleaning device for small-diameter tube holes in nuclear power evaporators as described in claim 3 or 4; The method comprises the following steps: Step 1, assembling an inner wall cleaning device for small-diameter tube holes in a nuclear power evaporator; Step 2, after connecting the connecting rod (6) to the hand drill, insert the inner wall cleaning device into the small-diameter pipe hole, and control the scouring pad (3) on the inner wall cleaning device to reciprocate at least once along the length direction of the small-diameter pipe hole; Step 3, cleaning the small-diameter tube holes one by one, and regularly replacing the scouring pad (3).

6. The method for cleaning the inner wall of a small-diameter tube hole in a nuclear power evaporator according to claim 5, characterized in that: The step 1 includes the following sub-steps: Sub-step 1, sleeve the pressing block 1 (2) onto the hand drill bolt (1), and make the large end cylinder (21) abut against the top cap (11); Sub-step 2, controlling the hand drill bolt (1) to rotate and penetrate the scouring pad (3); Sub-step 3, sleeve the second pressing block (4) onto the hand drill bolt (1); Sub-step 4, screwing the connecting tube (5) onto the threaded portion (13), and pressing the second pressing block (4) through the connecting tube (5), so that the small end cylinder (22) and the scouring pad (3) are pressed into the groove (41); Sub-step 5, screwing the connecting rod (6) onto the connecting pipe (5); Sub-step 6, fixing the anti-collision block (7) on the connecting rod (6) through the anti-threading screw (8).

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