A tool for removing stuck roller expansion tool heads of steam generator heat transfer tubes

Abstract

The present invention belongs to the technical field of nuclear power plant maintenance, and specifically relates to a tool for removing a stuck roller expansion tool head of a steam generator heat transfer tube. The present invention comprises: a T-type wrench, a cage extraction tool and a roller needle striking tool; when the roller expansion tool head structure is intact and undamaged, the T-type wrench is used to remove the roller expansion tool head; when the roller expansion tool head mandrel is broken but the cage is intact, the roller expansion tool head is removed using a cage extraction tool; when the roller expansion tool head mandrel is broken and the cage is damaged, the roller needle striking tool is used. The present invention is easy to operate, convenient for on-site application, improves work efficiency and reduces work time.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power plant maintenance, and in particular relates to a tool for removing a stuck roller expansion tool head of a steam generator heat transfer tube. Background Art

[0002] During the overhaul of nuclear power plant units, it is necessary to conduct eddy current inspection on the heat transfer tubes of horizontal steam generators and plug the heat transfer tubes that do not meet the acceptance requirements according to the inspection results. In accordance with the principle of radiation protection optimization, in order to avoid personnel entering the high radiation dose area inside the header, nuclear power plants at home and abroad generally use mechanical plugging equipment to remotely plug the heat transfer tubes.

[0003] The operation of mechanical plugging of heat transfer tubes includes two parts: rolling the heat transfer tube and plugging the heat transfer tube with a mechanical plug. The heat transfer tube rolling operation is to install a special roller expansion tool head with a diameter slightly larger than the inner wall of the heat transfer tube on the roller expansion manipulator to rotate inside the heat transfer tube to achieve the function of shaping and sizing the inner wall of the heat transfer tube. However, during the heat transfer tube rolling process, the roller expansion tool head may get stuck in the heat transfer tube due to reasons such as heat transfer tube deformation and equipment failure.

[0004] The roller expansion tool head includes a mandrel, 5 roller needles distributed around the center of the mandrel, a cage that fixes the mandrel and roller needles, and a bearing sleeve connected to the cage through a thread. The mandrel is divided into a functional part at the front end and a fixed part at the back half. The functional part is a nearly conical structure, that is, the diameter gradually increases from the end to the tail, while the fixed part at the back half is a cube structure used to fix with the roller tube manipulator; the roller needle is also a similar cone structure, but the diameter gradually decreases from the end to the tail of the roller needle. When the roller expansion tool is used, the pneumatic motor on the roller expansion manipulator drives the mandrel to drive the roller needle and the cage to rotate in the heat transfer tube. As the mandrel is fed during the rotation process, the roller needle on the cage will gradually expand outward to roll the inner wall of the heat transfer tube to achieve the purpose of shaping the inner wall of the heat transfer tube.

[0005] The roller expansion tool may get stuck in the heat transfer tube during use. The roller expansion tool head cannot be removed using conventional general tools or takes a long time to remove, which affects the equipment maintenance progress and causes a high radiation dose to the personnel. At the same time, the heat transfer tube sheet may be damaged during the removal of the roller expansion tool head.

[0006] In view of this situation, the present invention provides a tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool. Summary of the invention

[0007] The purpose of the present invention is to solve the problem that the roller expansion tool head may get stuck in the heat transfer tube due to deformation of the heat transfer tube, equipment failure, etc. during the heat transfer tube rolling process. The roller expansion tool head cannot be removed using conventional general tools or takes a long time to remove, which affects the equipment maintenance progress and causes a high radiation dose to the personnel. At the same time, the heat transfer tube sheet may be damaged during the removal of the roller expansion tool head. In view of this situation, the present invention provides a tool for removing the stuck roller expansion tool head of a steam generator heat transfer tube, which is easy to operate, convenient for on-site application, improves work efficiency, and reduces work time.

[0008] The technical solution adopted by the present invention is:

[0009] A tool for removing a stuck roller expansion tool head of a steam generator heat transfer tube comprises: a T-type wrench, a cage extraction tool and a roller needle striking tool; when the roller expansion tool head structure is intact and undamaged, the T-type wrench is used to remove the roller expansion tool head; when the core shaft of the roller expansion tool head is broken but the cage is intact, the roller expansion tool head is removed using the cage extraction tool; when the core shaft of the roller expansion tool head is broken and the cage is damaged, the roller needle striking tool is used.

[0010] The T-shaped wrench comprises a rotating handle and a connecting sleeve. The rotating handle is inserted into a through hole at the top of the connecting sleeve and is vertically connected to the connecting sleeve. A square hole is provided at the bottom of the connecting sleeve for connecting and fixing to a roller expansion tool head.

[0011] The cage extraction tool includes a rotating handle, a sliding hammer, a sliding hammer limit block and a threaded sleeve. The rotating handle is inserted into the through hole at the top of the threaded sleeve and is vertically connected to the threaded sleeve. The threaded sleeve is provided with a sliding hammer limit block, and the sliding hammer is sleeved on the threaded sleeve between the sliding hammer limit block and the rotating handle.

[0012] The roller needle knocking tool includes a sliding hammer, a sliding hammer limit block, a knocking needle locking nut, a knocking needle and a tool main rod. A sliding hammer limit block is provided in the middle of the tool main rod, a sliding hammer is sleeved between the top of the tool main rod and the sliding hammer limit block, a knocking needle is installed at the bottom end of the tool main rod, and the knocking needle locking nut is sleeved on the knocking needle.

[0013] The T-wrench connecting sleeve is inserted into the fixed part of the cube structure of the rear half of the roller expansion tool head, and then the T-wrench rotating handle is rotated in the opposite direction by manpower to drive the core shaft and the roller needle of the roller expansion tool head to rotate and eliminate the jamming. After the roller expansion tool head is loosened, it is taken out from the heat transfer tube.

[0014] Rotate the rotating handle of the cage extraction tool clockwise to connect the threaded sleeve at the front end with the thread at the end of the cage. After confirming that the thread is screwed to the bottom, use a sliding hammer to knock in the reverse direction so that the entire roller expansion tool head is subjected to an outward force, gradually eliminating the jamming between the roller expansion tool head and the inner wall of the heat transfer tube, and finally loosening and removing the roller expansion tool head in the heat transfer tube.

[0015] Before use, insert the tapping needle into the front fixing hole of the roller needle tapping tool, then tighten the tapping needle locking nut to fix the tapping needle, hold the roller needle tapping tool and place the front tapping needle against the end of one of the roller needles of the roller expansion tool head, use a sliding hammer to tap forward, and perform the above operations on the roller needles in turn until the jam between all roller needles and the core shaft is eliminated, then remove the core shaft, roller needle and remaining cage from the heat transfer tube in order, and finally confirm again that all the parts of the roller expansion tool head in the heat transfer tube have been removed.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention provides a tool for removing a stuck roller expansion tool head of a steam generator heat transfer tube, which can handle different stuck situations of the roller expansion tool head;

[0018] (2) The present invention provides a tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool, which is easy to operate and convenient for on-site application;

[0019] (3) The present invention provides a tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool, thereby improving operation efficiency and reducing operation time;

[0020] (4) The present invention provides a tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool, thereby reducing the radiation dose to personnel;

[0021] (5) The present invention provides a tool for removing a stuck head of a roller expansion tool for a steam generator heat transfer tube, which has a simple structure and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of a T-type wrench

[0023] Figure 2 Schematic diagram of the cage extraction tool

[0024] Figure 3 Schematic diagram of roller needle striking tool

[0025] In the figure: 1—rotating handle; 2—connecting sleeve; 3—rotating handle; 4—sliding hammer; 5—sliding hammer limit block; 6—threaded sleeve; 7—sliding hammer; 8—sliding hammer limit block; 9—tapping pin locking nut; 10—tapping pin; 11—tool main rod. DETAILED DESCRIPTION

[0026] The following is a further detailed description of a tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool provided by the present invention in conjunction with the accompanying drawings and specific embodiments.

[0027] The invention provides a tool for removing a stuck roller expansion tool head of a steam generator heat transfer tube, comprising a T-type wrench, a rotating cage extraction tool and a roller needle striking tool.

[0028] like Figure 1 As shown, the T-type wrench includes a rotating handle 1 and a connecting sleeve 2. The rotating handle 1 is inserted into the through hole at the top of the connecting sleeve 2 and is vertically connected to the connecting sleeve 2. A square hole is opened at the bottom end of the connecting sleeve 2 for connecting and fixing with the roller expansion tool head.

[0029] like Figure 2 As shown, the cage extraction tool includes a rotating handle 3, a sliding hammer 4, a sliding hammer limit block 5 and a threaded sleeve 6. The rotating handle 3 is inserted into the through hole at the top of the threaded sleeve 6 and is vertically connected to the threaded sleeve 6. The threaded sleeve 6 is provided with a sliding hammer limit block 5. The sliding hammer 4 is sleeved on the threaded sleeve 6 between the sliding hammer limit block 5 and the rotating handle 3.

[0030] like Figure 3 As shown, the roller needle tapping tool includes a sliding hammer 7, a sliding hammer limit block 8, a tapping needle locking nut 9, a tapping needle 10 and a tool main rod 11. A sliding hammer limit block 8 is provided in the middle of the tool main rod 11, a sliding hammer 7 is sleeved between the top of the tool main rod 11 and the sliding hammer limit block 8, a tapping needle 10 is installed at the bottom end of the tool main rod 11, and the tapping needle locking nut 9 is sleeved on the tapping needle 10.

[0031] The specific method of removing the roller expansion tool head is as follows:

[0032] When the roller expansion tool head is intact and undamaged, use a T-type wrench to remove the roller expansion tool head. The specific operation method is as follows: insert the T-type wrench connecting sleeve 2 into the fixed part of the cube structure of the rear half of the roller expansion tool head, and then rotate the T-type wrench rotating handle 1 in the opposite direction by manpower to drive the core shaft of the roller expansion tool head and the 5 roller needles to rotate and eliminate the jamming. After the roller expansion tool head is loosened, remove it from the heat transfer tube.

[0033] When the core shaft of the roller expansion tool head is broken but the cage is intact, use the cage extraction tool to remove the roller expansion tool head. The specific operation method is as follows: first, rotate the rotating handle of the cage extraction tool clockwise to connect the threaded sleeve 6 at the front end with the thread at the end of the cage. After confirming that the thread is screwed to the bottom, use the sliding hammer 4 to knock in the reverse direction so that the entire roller expansion tool head is subjected to an outward force, gradually eliminating the jamming between the roller expansion tool head and the inner wall of the heat transfer tube, and finally loosening and removing the roller expansion tool head in the heat transfer tube.

[0034] When the core shaft of the roller expansion tool head is broken and the cage is damaged, use the roller needle tapping tool. The specific operation method is as follows: Before use, insert the tapping needle 10 into the front fixing hole of the roller needle tapping tool, and then tighten the tapping needle locking nut 9 to fix the tapping needle. Hold the roller needle tapping tool and hold the front tapping needle 10 against the end of one of the roller needles of the roller expansion tool head, and use the sliding hammer 7 to tap forward. Perform the above operation on the 5 roller needles in turn until the jam between all roller needles and the core shaft is eliminated, and then remove the core shaft, roller needles and remaining cages from the heat transfer tube in order, and finally confirm again that all the parts of the roller expansion tool head in the heat transfer tube have been removed.

[0035] The above content uses the work of removing a stuck roller expansion tool head as an example to explain the method of using the tool provided by the present invention. The stuck removal tool provided by the present invention is not only suitable for the work of removing a stuck roller expansion tool head of a heat transfer tube of a steam generator in a nuclear power plant, but can also be applied to the work of removing a stuck roller expansion tool head of the same type of structure.

[0036] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or changes based on the technical scheme and inventive concept of the present invention should be covered within the protection scope of the present invention.

Claims

1. A tool for removing the stuck head of a steam generator heat transfer tube roller expansion tool, characterized in that: include: T-type wrench, cage extraction tool and roller needle striking tool; when the roller expansion tool head is in good structure and without damage, use the T-type wrench to remove the roller expansion tool head; when the roller expansion tool head mandrel is broken but the cage is intact, use the cage extraction tool to remove the roller expansion tool head; when the roller expansion tool head mandrel is broken and the cage is damaged, use the roller needle striking tool; The T-shaped wrench comprises a rotating handle and a connecting sleeve. The rotating handle is inserted into a through hole at the top of the connecting sleeve and vertically connected to the connecting sleeve. A square hole is opened at the bottom of the connecting sleeve for connecting and fixing with the roller expansion tool head. The cage extraction tool comprises a rotating handle, a sliding hammer, a sliding hammer stopper and a threaded sleeve. The rotating handle is inserted into the through hole at the top of the threaded sleeve and is vertically connected to the threaded sleeve. The threaded sleeve is provided with a sliding hammer stopper. The sliding hammer is sleeved on the threaded sleeve between the sliding hammer stopper and the rotating handle. The roller needle knocking tool includes a sliding hammer, a sliding hammer limit block, a knocking needle locking nut, a knocking needle and a tool main rod. A sliding hammer limit block is provided in the middle of the tool main rod, a sliding hammer is sleeved between the top of the tool main rod and the sliding hammer limit block, a knocking needle is installed at the bottom end of the tool main rod, and the knocking needle locking nut is sleeved on the knocking needle.

2. A tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool according to claim 1, characterized in that: Insert the T-wrench connecting sleeve into the fixed part of the cube structure of the rear half of the roller expansion tool head, and then rotate the T-wrench rotating handle in the opposite direction by manpower to drive the core shaft and roller needle of the roller expansion tool head to rotate and eliminate the jam. After the roller expansion tool head is loosened, take it out of the heat transfer tube.

3. A tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool according to claim 1, characterized in that: Rotate the rotating handle of the cage extraction tool clockwise to connect the threaded sleeve at the front end with the thread at the end of the cage. After confirming that the thread is screwed to the bottom, use a sliding hammer to knock in the reverse direction so that the entire roller expansion tool head is subjected to an outward force, gradually eliminating the jamming between the roller expansion tool head and the inner wall of the heat transfer tube, and finally loosening and removing the roller expansion tool head in the heat transfer tube.

4. A tool for removing a stuck head of a steam generator heat transfer tube roller expansion tool according to claim 1, characterized in that: Before use, insert the tapping needle into the front fixing hole of the roller needle tapping tool, then tighten the tapping needle locking nut to fix the tapping needle, hold the roller needle tapping tool and place the front tapping needle against the end of one of the roller needles of the roller expansion tool head, use a sliding hammer to tap forward, and perform the above operations on the roller needles in turn until the jam between all roller needles and the core shaft is eliminated, then remove the core shaft, roller needle and remaining cage from the heat transfer tube in order, and finally confirm again that all the parts of the roller expansion tool head in the heat transfer tube have been removed.

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