Horizontal steam generator plugging bolt protection cover and its dismounting tool

Abstract

The present application belongs to the field of mechanical device and transportation technology, and particularly relates to a horizontal steam generator blocking plate bolt protection cover and a dismounting tool thereof. The present application comprises four split type protection covers, which are installed in cooperation to cover all the collecting pipe blocking plate bolts. The dismounting tool comprises two connecting rods, the two ends of which are provided with pin controls, two connecting rods one and two are connected through short screw tail cylindrical pins to form a self-locking rhombus block, one corner of the self-locking rhombus block is connected with the bottom of a long rod through a long screw tail cylindrical pin, and the other symmetrical corner is connected with one end of a steel wire rope through a short screw tail cylindrical pin, the steel wire rope is inserted into the long rod, a gravity rod is installed on the steel wire rope, and the other end of the steel wire rope is provided with a handle. The present application prevents the steam generator collecting pipe blocking plate bolts from being damaged, or being jammed and stuck due to foreign matters entering the threaded connection of the blocking plate bolts, thereby avoiding the influence on the key path of nuclear island maintenance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical devices and transportation technology, and particularly relates to a horizontal steam generator blocking plate bolt protective cover and a dismounting tool thereof. BACKGROUND

[0002] The steam generator is one of the important devices of a nuclear power plant, and its function is to transfer the heat of the primary coolant to the secondary loop feed water to heat it into steam.

[0003] During the disassembly overhaul of a horizontal steam generator of a certain nuclear power plant, eddy current detection needs to be performed on the heat transfer pipes of the steam generator. Before the eddy current detection, a special long rod tool needs to be used to install the blocking plate in the blocking plate groove at the bottom of the collecting pipe, which is 5 meters away from the collecting pipe opening of the steam generator, so as to isolate the steam generator from the primary loop pipeline and ensure that the eddy current detection of the heat transfer pipes of the steam generator does not affect the water level rise of the primary loop.

[0004] The blocking plate of the steam generator collecting pipe contains 12 special fastening bolts with a specification of M20. In order to facilitate the identification of the matching condition of the blocking plate bolt and the long rod tool for dismounting the blocking plate at the collecting pipe opening, special marks need to be set on the head of the bolt, and therefore the screw thread of the screw rod of the bolt needs to be 2-3 threads higher than the nut.

[0005] During the eddy current detection of the heat transfer pipes, there is a risk of bumping the blocking plate and the blocking plate bolt, and the rust residues, boron crystals and other contaminants brought out of the heat transfer pipes by the eddy current probe during the eddy current detection process will fall into the threaded connection part of the blocking plate bolt of the collecting pipe, thereby causing the blocking plate bolt to be frequently stuck during dismounting. If the steam generator blocking plate bolt is stuck and cannot be removed smoothly, the dismounting work of the entire blocking plate will be delayed; if the sticking is serious, personnel need to enter the inside of the collecting pipe to perform the dismounting operation of the nut, which greatly increases the radiation dose and industrial safety risk of the personnel. When the steam generator blocking plate bolt is stuck, if the defect cannot be quickly treated within a limited time, it will directly affect the main line progress.

[0006] In view of the above problems, maintenance personnel try to use rubber pads and other foreign matter prevention tools to protect the blocking plate bolt, but because the collecting pipe opening of the steam generator is smaller than the diameter of the blocking plate, the rubber pads and other foreign matter prevention tools will fall off and fall into the threaded connection part of the blocking plate bolt during the removal process, thereby causing the blocking plate bolt to be stuck, and the problem of the blocking plate bolt being stuck cannot be fundamentally solved. SUMMARY

[0007] The present application aims to provide a horizontal steam generator blocking plate bolt protective cover and a dismounting tool thereof, which are simple in structure and easy to operate.

[0008] The technical scheme adopted by the present application is as follows:

[0009] The horizontal steam generator blocking plate bolt protective cover comprises four split protective covers, which are installed in cooperation to cover all the collecting pipe blocking plate bolts.

[0010] The split protective cover comprises a front cover plate, a rear cover plate, side plates, and a top plate.

[0011] The rear cover plate is a circular arc plate with a central angle of 90°.

[0012] A circular hole is arranged at the center of the front cover plate and the rear cover plate.

[0013] A circular hole is arranged at the center of the top plate.

[0014] The dismounting tool of the horizontal steam generator blocking plate bolt protective cover comprises a long rod, a connecting rod one, a connecting rod two, a short screw tail cylindrical pin, a long screw tail cylindrical pin, a gravity rod, a steel wire rope, a handle, and pin holes are arranged at the two ends of the connecting rod one and the connecting rod two.

[0015] The long rod is divided into several segments, each segment has the same length, and the segments are connected through threads.

[0016] The connecting rod one, the connecting rod two, and the steel wire rope are assembled at the end of the bottom rod of the long rod through the short screw tail cylindrical pin, the long screw tail cylindrical pin, and a nut, and the gravity rod is sleeved on the steel wire rope to form a self-locking rhombus block.

[0017] The steel wire rope passes through the other segments of the long rod in sequence, the segments of the long rod are connected through the threads arranged at the ends of the rods, and the handle is installed at the top end of the steel wire rope.

[0018] The guarantee short screw tail cylindrical pin, long screw tail cylindrical pin, the joint has a certain rotation space, the gravity rod guarantees the reliable opening of the self-locking rhombus block when being put into place and loosening the steel wire rope.

[0019] Compared with the prior art, the present application has the beneficial effects that:

[0020] (1) The present application provides a horizontal steam generator baffle plate bolt protective cover and its dismounting tool, which can prevent the vortex detection equipment from colliding and damaging the steam generator baffle plate bolt during vortex detection of the steam generator.

[0021] (2) The present application provides a horizontal steam generator baffle plate bolt protective cover and its dismounting tool, which can effectively prevent the dirt brought by vortex detection of the heat pipe from entering the threaded connection part of the steam generator baffle plate bolt, avoid the baffle plate bolt from being stuck, ensure the smooth progress of the baffle plate removal work of the steam generator, and ensure the main line progress.

[0022] (3) The present application provides a horizontal steam generator baffle plate bolt protective cover and its dismounting tool, the long rod tool is connected with the baffle plate bolt protective cover through a self-locking rhombus module, the connection is safe, reliable, convenient and fast, the protective cover can be smoothly taken out after being tilted, and the installation of the baffle plate protective cover does not affect the normal use of the vortex detection device in the collecting pipe.

[0023] (4) The present application provides a horizontal steam generator baffle plate bolt protective cover, each set of baffle plate bolt protective cover is composed of four split protective covers, which can smoothly enter and exit the steam generator collecting pipe opening, and can effectively ensure that the protective cover does not deviate during the dismounting process using a single dismounting tool; the long rod of the special tool is divided into multiple sections and connected through threads, which meets the limitation of small space on site and is convenient to store.

[0024] (5) The present application provides a dismounting tool for a horizontal steam generator baffle plate bolt protective cover, which can realize the completion of the work at the collecting pipe opening by personnel, avoid the entry of personnel into the collecting pipe to cause large-dose exposure, and does not affect the normal use of the vortex detection device in the collecting pipe. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a front view of the horizontal steam generator baffle plate bolt protective cover provided by the present application.

[0026] Figure 2 It is a left view of the horizontal steam generator baffle plate bolt protective cover provided by the present application.

[0027] Figure 3 It is a plan view of the horizontal steam generator baffle plate bolt protective cover provided by the present application.

[0028] Figure 4 It is a front view of the dismounting tool for the horizontal steam generator baffle plate bolt protective cover.

[0029] Figure 5 Left view of the tool for disassembling and assembling the bolt guard of this type of horizontal steam generator;

[0030] In the diagram: 1-Front cover plate, 2-Rear cover plate, 3-Side plate, 4-Top plate, 5-Long rod, 6-Connecting rod one, 7-Connecting rod two, 8-Short threaded cylindrical pin, 9-Long threaded cylindrical pin, 10-Nut, 11-Gravity rod, 12-Wire rope, 13-Handle. Detailed Implementation

[0031] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a protective cover for the plug bolts of a horizontal steam generator and its disassembly and assembly tools.

[0032] like Figures 1 to 3 As shown, this invention provides a protective cover for the plug bolts of a horizontal steam generator, comprising four separate protective covers. These four separate protective covers are installed together to completely cover the plug bolts of the manifold. Taking one as an example, it includes a front cover plate 1, a rear cover plate 2, side plates 3, and a top plate 4. The front cover plate 1 is a rectangular plate with side plates 3 welded to both sides. The rear cover plate 2 is an arc plate with a central angle of 90°, welded to the two side plates 3. The top plate 4 is welded to the top. The connections are made using MMA manual welding. The circular holes on the front cover plate 1 allow for easy removal using specialized tools even if the protective cover tipps over. The rear cover plate 2 has the same design.

[0033] like Figure 4 and Figure 5 As shown, the tool for disassembling and assembling the bolt guard of this horizontal steam generator includes a long rod 5, two connecting rods 6, two connecting rods 7, three short threaded cylindrical pins 8, four long threaded cylindrical pins 9, four nuts 10, a gravity rod 11, a steel wire rope 12 (5m in length), and a handle 13. The long rod 5 is divided into five sections, each 1m long, and the sections are connected by threads. The bottom end of the long rod 5 has a rectangular groove and a fixing hole for the long threaded cylindrical pin 9.

[0034] Connecting rod 1 (6), connecting rod 2 (7), and wire rope 12 are assembled at the end of the bottommost rod of long rod 5 using short threaded cylindrical pins (8), long threaded cylindrical pins (9), and nuts (10, 4 in total). A gravity rod (11) is fitted onto the wire rope 12 to form a self-locking diamond block. The wire rope 12 is then passed through the other four sections of long rod 5 in sequence, connecting the five sections of long rod 5 together using threaded joints at the ends of the rods. A handle (13) is installed at the top of the wire rope 12. After assembly, a certain amount of rotation space should be ensured at the cylindrical pin connection points, and the gravity rod (11) should ensure that the self-locking diamond block reliably opens when lowered into position and the wire rope 12 is released.

[0035] The specific steps are as follows:

[0036] I. Installation of the baffle bolt protective cover:

[0037] 1. Adjust the handle 13 to tighten the wire rope 12, and keep the self-locking diamond block in the retracted state.

[0038] 2. Slowly put the long rod of the special tool into the round hole on the top plate 4 of the baffle bolt protective cover, and tighten the wire rope 12 during the process to keep the self-locking diamond block in the retracted state.

[0039] 3. Stop when the long rod of the special tool is inserted into the top hole of the baffle bolt protective cover by about 65 mm (to ensure that the self-locking diamond block of the special tool is below the top plate of the baffle bolt protective cover, and there is enough space for the self-locking diamond block to expand; at the same time, the bottom of the long rod of the special tool 5 will not knock the baffle of the steam generator), and slowly loosen the wire rope 12 to make the self-locking diamond block of the special tool open due to the weight and the action of the gravity rod 11.

[0040] 4. Hold the top of the long rod 5 of the special tool, and personnel can install the baffle bolt protective cover of the steam generator at the steam generator header, and the process should be slow and cannot knock the heat transfer tube or the header wall.

[0041] 5. After the baffle bolt protective cover of the steam generator is installed at the specified position, slightly lower the long rod 5 until it is inserted into the top hole of the baffle bolt protective cover by about 65 mm.

[0042] 6. Adjust the handle to tighten the wire rope 12, retract the self-locking diamond block, and slowly move the long rod 5 upward to remove the entire special tool from the baffle bolt protective cover of the steam generator.

[0043] 7. Use the same method to install the four bolt protective covers in turn to cover all the baffle bolt of the header.

[0044] 8. The installation of the baffle bolt protective cover of the steam generator is completed.

[0045] II. Removal of the baffle bolt protective cover:

[0046] 1. Adjust the handle 13 to tighten the wire rope 12, and keep the self-locking diamond block in the retracted state.

[0047] 2. Slowly put the long rod 5 of the special tool into the round hole on the top plate 4 of the baffle bolt protective cover, and tighten the wire rope 12 during the process to keep the self-locking diamond block in the retracted state.

[0048] 3. Stop when the long rod 5 of the special tool is inserted into the top hole of the baffle bolt protective cover by about 65 mm (to avoid knocking the baffle of the steam generator), and slowly loosen the wire rope 12 to make the self-locking diamond block of the special tool open due to the weight and the action of the gravity rod 11.

[0049] 4. Slowly take out the special tool and the shield as a whole, and slightly lower the long rod 5 when the steam generator plug plate bolt shield reaches the designated position.

[0050] 5. Tighten the steel wire rope 12, collect the self-locking diamond blocks, take out the special tool, and clean the special tool and the steam generator plug plate bolt shield.

[0051] 6. Use the same method to sequentially remove the four bolt shields installed on the collector pipe plug plate;

[0052] 7. The steam generator plug plate bolt shield removal work is completed.

[0053] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art should be covered within the protection scope of the present application according to the technical solution and the inventive concept of the present application, and the equivalent replacement or change of the present application within the technical range disclosed by the present application.

Claims

1. A horizontal steam generator tie rod guard characterized by: The application relates to a four-piece split protective cover which is installed in cooperation and covers all the bolt holes of the collecting pipe blocking plate, wherein the split protective cover comprises a front cover plate (1), a rear cover plate (2), side plates (3) and a top plate (4), the front cover plate (1) is a rectangular plate, the side plates (3) are welded on the two sides of the front cover plate (1), the rear cover plate (2) is an arc plate which is welded with the two side plates (3), and the top plate (4) is welded on the top and is connected by MMA manual welding; the rear cover plate (2) is an arc plate with a central angle of 90 degrees; the front cover plate (1) and the rear cover plate (2) are provided with round holes at the centers; the top plate (4) is provided with a round hole at the center; the round hole of the front cover plate (1) can be used for smoothly taking out the protective cover by using special tools when the protective cover is tilted.

2. The PFP for a horizontal steam generator as set forth in claim 1, characterized by: The special tool comprises a long rod (5), a connecting rod one (6), a connecting rod two (7), a short screw tail cylindrical pin (8), a long screw tail cylindrical pin (9), a gravity rod (11), a steel wire rope (12) and a handle (13), the two ends of the connecting rod one (6) and the connecting rod two (7) are provided with pin controls, the two connecting rod ones (6) and the two connecting rod twos (7) form a self-locking rhombus block through the short screw tail cylindrical pin (8), one corner of the self-locking rhombus block is connected with the bottom of the long rod (5) through the long screw tail cylindrical pin (9), and the other symmetrical corner is connected with one end of the steel wire rope (12) through the short screw tail cylindrical pin (8), the steel wire rope (12) penetrates into the long rod (5), the gravity rod (11) is installed on the steel wire rope (12), and the other end of the steel wire rope (12) is provided with the handle (13).

3. The PFP for a horizontal steam generator as set forth in claim 2, characterized by: The long rod (5) is divided into several sections, each section has the same length, and the sections are connected through threads, and the end of the bottom rod of the long rod (5) is provided with a rectangular groove and a fixing hole of the long screw tail cylindrical pin (9).

4. The PFP for a horizontal steam generator as set forth in claim 3, characterized in that: The connecting rod one (6), the connecting rod two (7) and the steel wire rope (12) are assembled at the end of the bottom rod of the long rod (5) through the short screw tail cylindrical pin (8), the long screw tail cylindrical pin (9) and a nut (10), the gravity rod (11) is sleeved on the steel wire rope (12), and a self-locking rhombus block is formed.

5. The PFP for a horizontal steam generator as set forth in claim 3, characterized in that: The steel wire rope (12) penetrates through other sections of the long rod (5) in sequence, the sections of the long rod (5) are connected through thread pairs arranged at the ends of the rods, and the handle (13) is installed at the top end of the steel wire rope (12).

6. The PFP for a horizontal steam generator as set forth in claim 5, characterized in that: The short screw tail cylindrical pin (8), the long screw tail cylindrical pin (9) and the connecting part have a certain rotating space, and the gravity rod (11) ensures that the self-locking rhombus block can be reliably opened when being lowered into place and the steel wire rope (12) is loosened.

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