Device and method for relieving remote expansion of cushion block locking cap of heat insulation sleeve

Abstract

The invention belongs to the technical field of nuclear power, and particularly relates to a device and method for relieving remote expansion of a cushion block locking cap of a heat insulation sleeve. Comprising a locking cap expansion device and a long rod, the long rod is used for remote operation above a pool, and the locking cap expansion device comprises a positioning pin, a positioning cylinder, a clamping gripper, an aligning and screwing operation head, an expansion head and a pressing expansion operation head. The device has the beneficial effects that a long-distance long rod is adopted to operate screwing positioning alignment and pressing expansion, and remote operation of locking of the cushion block locking cap is achieved. A special device integrating positioning of an expansion tool, screwing positioning of an expansion head, clamping and fixing and pressing expansion is adopted, underwater remote expansion integrated operation of the relieving cushion block locking cap is achieved, and the process steps are simplified.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear power, and particularly relates to a device and method for remote expansion of a lock cap of a spacer block of a spacer sleeve. BACKGROUND

[0002] The spacer sleeve is a component of a control rod drive mechanism, and is installed in a CRDM pipe seat on a top cover of a pressure vessel in a suspended manner. The installation mode is radial gap fit and axial unconstrained. During operation of the unit, the spacer sleeve is affected by vibration caused by flow of a primary loop medium, which causes impact and abrasion at a joint between an upper end of the spacer sleeve and a flange of the CRDM pipe seat, and causes the spacer sleeve to drop in height. With the increase of the operation time, the abrasion of the upper end of the spacer sleeve causes the spacer sleeve to drop in position, and if not intervened, the spacer sleeve will drop in position more and more, and finally the whole spacer sleeve will drop after the upper end is completely abraded.

[0003] At present, in the nuclear power industry, a common relief scheme is to install a relief spacer block on a top cover plate of a control rod guide tube of an upper in-core component. The spacer block is composed of a cone and a flange, the flange has three groups of uniformly distributed bolts and lock caps, and the flange has two evenly distributed positioning holes. The positioning of the spacer block relies on the cooperation of the positioning holes and anti-rotation pins on the top cover plate of the guide tube, and the fixation of the spacer block relies on the fastening of the three groups of bolts, and the anti-loosening is achieved by the lock caps matched with the bolts.

[0004] Since the contact dose of the guide tube is about 15 mSv / h, boracic acid water needs to be used for shielding, so the installation of the spacer block on the upper end surface of the guide tube needs to be performed underwater. The guide tube is immersed in boracic acid water (boracic acid water concentration 2400-2500 ppm), and an operator stands on an auxiliary bridge above the water pool to perform remote operation. SUMMARY

[0005] The purpose of the present application is to provide a device and method for remote expansion of a lock cap of a spacer block of a spacer sleeve, which can realize the positioning of an expansion tool, the positioning of an expansion head, clamping and fixation, and downward expansion in one body, and is used for underwater remote expansion of the lock cap of the spacer block.

[0006] The technical scheme of the present application is as follows: a device for remote expansion of a lock cap of a spacer block of a spacer sleeve, comprising a lock cap expansion device and a long rod, the long rod is used for remote operation above a water pool, and the lock cap expansion device comprises a positioning pin, a positioning cylinder, a clamping claw, an alignment and screwing operation head, an expansion head and a downward expansion operation head.

[0007] The positioning pin is in the shape of a cylinder with a tapered head, which is inserted into the mounting process hole on the flange of the cushion block, cooperates with the positioning cylinder, and realizes the positioning of the locking cap expansion device on the cushion block.

[0008] The positioning cylinder is located at the center of the locking cap expansion device, is inserted into the center hole of the guide cylinder upper cover plate through the center hole of the cushion block, and plays a centering role.

[0009] The clamping gripper has three, which are evenly installed on the positioning cylinder through a pin shaft, can rotate around the pin shaft, and realize the fixation with the cushion block.

[0010] The clamping and releasing of the clamping gripper are realized through the clamping gripper driving rod and the clamping cylinder. When the lower part of the clamping cylinder is supplied with gas, the clamping gripper driving rod moves upward, contacts through the wedge surface of the gripper, drives the gripper to fold and release; when the upper part of the clamping cylinder is supplied with gas, the clamping gripper driving rod moves downward, contacts through the wedge surface of the gripper, drives the gripper to be spread open, and realizes the clamping and fixation with the inner tapered surface of the cushion block.

[0011] The upper end of the alignment screwing operation head is a tapered outer square structure, which cooperates with the inner square of the long rod, and plays a role of rotating the expansion head.

[0012] The expansion head includes a positioning hexagonal head and a notch column. The positioning hexagonal head realizes expansion and contraction through the action of the upper spring force. The positioning hexagonal head cooperates with the inner hexagonal of the bolt. Through the positional relationship of the components of the expansion head, the notch column is positioned with the bolt notch.

[0013] The downward expansion operation head is a rotating component, which is driven to rotate by the long rod. The lower end is a screw pair, which drives the pressure plate to move up and down through the rotation of the screw rod. When moving downward, the downward rotating expansion head is pressed, the notch column is pressed to deform the locking cap to the bolt notch, and the locking is realized.

[0014] A method for relieving the remote expansion of the locking cap of the cushion block of the heat insulation sleeve, comprising the following steps: Step 1: Lower the locking cap expansion device, determine the position of the locking cap expansion device by cooperating the positioning pin with the positioning hole on the flange of the cushion block and cooperating the positioning cylinder with the center hole of the cushion block; Step 2: Observe the position of the positioning hexagonal head of the expansion head and the bolt head notch, align the screwing operation head by rotating the long rod, and align the notch column with the bolt head notch; Step 3: Lower the locking cap expansion device so that it is completely seated on the cushion block; Step 4: Supply gas to the cylinder to drive the clamping gripper driving rod to move downward, so that the clamping gripper is clamped and fixed with the cushion block; Step 5: the long rod is screwed down to press the expansion operation head, the driving nut pair is pressed to align the screwing operation head, and then the gap column is extruded to deform the locking cap, which is embedded into the gap of the bolt head to prevent loosening.

[0015] The present application has the advantages that the long rod operation is used to screw, position, align and press down and expand, the long distance operation of the pad locking cap is realized, the positioning, expansion head screwing positioning, clamping and fixing and down pressing expansion are integrated into one device by using the expansion tool, the underwater long distance expansion integrated operation of the pad locking cap is realized, and the process steps are simplified. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a pad composition diagram; Figure 2 is a locking cap expansion mechanism structure diagram; Figure 3 is a locking cap expansion mechanism installation diagram; Figure 4 is a locking cap expansion mechanism operation diagram; Figure 5 is a clamping installation diagram; Figure 6 is a down pressing expansion diagram; Figure 7 is an expansion head structure diagram.

[0017] In the figure: 1, pad; 12, bolt; 11, locking cap; 2, locking cap expansion device; 3, long rod; 21, positioning pin; 22, positioning cylinder; 23, clamping claw; 24, aligning screwing operation head; 25, expansion head; 26, down pressing expansion operation head; 27, disc; 28, down pressing nut; 231, clamping claw driving rod; 232, clamping cylinder; 251, positioning hex head; 252, gap column; 253, pressing spring. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0019] In order to solve the problem of wear and tear of the heat insulation sleeve during the power operation of the nuclear reactor, a special pad is designed, which is installed on the upper part of the control rod guide tube of the upper internal component corresponding to the position of the heat insulation sleeve, supports the heat insulation sleeve, separates the end head from the pipe seat to avoid the end head from colliding with the CRDM pipe seat, and increases the positioning of the lower part of the horn to reduce the radial vibration and wear.

[0020] The relief pad is fixed on the cover plate of the guide cylinder by three bolts. Since reliable mechanical anti-loosening locking structure needs to be provided for the internal components of the reactor, the three bolts are provided with a mature locking cap anti-loosening design. One side of the locking cap is fixed with the pad, and the other side is fixed with the bolt to prevent loosening. The locking cap is fixed with the bolt by means of three notches formed in the head of the bolt, and the locking cap is deformed and expanded into the notches to prevent rotation. The expansion of the locking cap needs to be operated remotely underwater after the pad bolt is tightened.

[0021] The present application provides a device and method for remotely expanding the locking cap of the relief pad of the thermal insulation sleeve. 1) For the installation and positioning of the expansion tool, the positioning cylinder and the center hole of the pad, the positioning pin and the process installation hole on the pad are matched to achieve positioning.

[0022] 2) For the positioning of the expansion head, the bolt and the locking cap in the circumferential direction, the head of the expansion head is designed as an external hexagonal structure, and the external hexagonal structure is inserted into the internal hexagonal hole of the bolt by rotating the long rod to position the expansion head.

[0023] 3) For the expansion of the locking cap, three cylinders are matched with the three notches of the bolt head to deform the locking cap by extrusion.

[0024] 4) For the problem of the pressure of the extrusion, a nut and screw pair structure is used, and the nut is driven downward by rotating the operating rod to drive the deformation of the locking cap.

[0025] As shown in Figure 1 , the pad 1 that needs to be locked and prevented from loosening is composed of a bolt 12 and a locking cap 11. The present application is to lock and prevent loosening of the locking cap 11 and the bolt 12.

[0026] A device for remotely expanding the locking cap of the relief pad of the thermal insulation sleeve includes a locking cap expansion device 2 and a long rod 3, wherein the long rod 3 is used for remote operation of personnel above the water pool.

[0027] The locking cap expansion device 2 is used to lock the locking cap 11 and the bolt 12 after the installation of the pad 1. The use scenario of the locking cap expansion device 2 is that the pad 1 has been fastened with the bolt 12, and only the locking cap 11 is not locked. The function of the locking cap expansion device 2 is to remotely lock the locking cap 11.

[0028] As shown in Figure 2 , the locking cap expansion device 2 includes a positioning pin 21, a positioning cylinder 22, a clamping claw 23, an alignment and screwing operation head 24, an expansion head 25, a downward expansion operation head 26, a disc 27, and a downward nut 28.

[0029] The positioning pin 21 is fixed on the disc 27, and the positioning cylinder 22 is a central component of the locking cap expansion device 2. The positioning pin 21 and the positioning cylinder 22 are matched with the flange process hole and the central hole of the gasket 1 respectively, and play a positioning role.

[0030] The three clamping claws 23 are fixed on the positioning cylinder 22 through the pin shaft and can rotate around the pin shaft.

[0031] The alignment screwing operation head 24 is composed of three parts which are evenly arranged on the disc 27. The three parts are not constrained in the hole and can rotate through the long rod 3 or move up and down between the pressing nut 28 and the disc 27.

[0032] The expansion head 25 is fixed at the lower end of the alignment screwing operation head 24 and is a direct functional component of the locking operation. The expansion head 25 can rotate and move up and down with the alignment screwing operation head 24.

[0033] The pressing expansion operation head 26 is fixed on the disc 27 through the support seat and can rotate under the drive of the long rod 3. The lower end of the pressing expansion operation head 26 is a threaded column structure which cooperates with the pressing nut 28 to form a threaded pair. When the pressing expansion operation head 26 rotates, the pressing nut 28 moves up and down, driving the expansion head 25 to move down, thereby realizing the expansion of the locking cap 11.

[0034] The positioning pin 21 is a tapered head guide cylinder which is fixed on the disc 27 of the entire device. The function of the positioning pin 21 is to be inserted into the installation process hole on the flange of the gasket 1 and cooperate with the positioning cylinder 22 to realize the positioning of the locking cap expansion device 2 on the gasket 1.

[0035] The positioning cylinder 22 is located at the center of the locking cap expansion device 2 and is inserted into the central hole of the guide cylinder upper cover plate through the central hole of the gasket 1, thereby playing a centering role.

[0036] The three clamping claws 23 are evenly arranged on the positioning cylinder 22 through the pin shaft and can rotate around the pin shaft to realize the fixation with the gasket. The clamping and releasing of the clamping claws 23 are realized by the clamping claw driving rod 231 and the clamping cylinder 232. When the lower part of the clamping cylinder 232 is supplied with gas, the clamping claw driving rod 231 moves up, drives the clamping claw 23 to close and release through the wedge surface contact of the clamping claw. When the upper part of the clamping cylinder 232 is supplied with gas, the clamping claw driving rod 231 moves down, drives the clamping claw 23 to be opened through the wedge surface contact of the clamping claw, thereby realizing the clamping fixation with the inner tapered surface of the gasket.

[0037] The three clamping claws 23 are fixed on the positioning cylinder 22 through the pin shaft and can rotate around the pin shaft. The clamping cylinder 232 is fixed on the upper end of the positioning cylinder 22 and is connected with the clamping claw driving rod 231 through the cylinder piston, thereby forming an integral body. The lower end of the clamping claw driving rod 231 is in contact with the wedge-shaped surface of the clamping claw 23, and the opening and closing of the clamping claw are realized through the wedge surface contact.

[0038] The alignment screwing operation head 24 is a tapered outer square structure at the upper end, matched with the inner square of the long rod 3, to rotate the expansion head 25.

[0039] The alignment screwing operation head 24 is installed on the disc 27 by three, without constraint in the hole, and can rotate through the long rod 3 or move up and down between the pressing nut 28 and the disc 27.

[0040] The expansion head 25 is a direct key function component of the locking cap expansion device 2, composed of a positioning hex head 251, an opening column 252 and a pressing spring 253. The positioning hex head 251 is limited to axial movement only by the key groove in the installation hole, and the pressing spring 253 provides downward pressure to maintain the cooperation between the positioning hex head 251 and the inner hex groove of the bolt 12. The positioning hex head 251 can be extended and retracted by the action of the spring force at the top, and cooperates with the inner hex of the bolt 12 to realize the positioning of the opening column 252 and the opening of the bolt 12 through the positional relationship of the components of the expansion head 25.

[0041] The downward expansion operation head 26 is a rotating component driven to rotate by the long rod 3, and its lower end is a threaded pair that drives the pressing plate to move up and down by rotating the screw rod. When moving downward, it presses the rotating expansion head 25, and the opening column 252 presses to drive the locking cap 11 to deform towards the opening of the bolt 12, achieving locking.

[0042] A method for relieving the locking cap of the heat insulation sleeve cushion pad by remote expansion, comprising the following steps: Step 1: Lower the locking cap expansion device 2, and determine the position of the locking cap expansion device 2 by cooperating the positioning pin 21 with the positioning hole on the flange of the cushion pad and cooperating the positioning cylinder 22 with the center hole of the cushion pad. Step 2: Observe the position of the positioning hex head 251 of the expansion head 25 and the opening of the head of the bolt 12, and align the opening column 252 with the opening of the head of the bolt 12 by rotating the alignment screwing operation head 24 through the long rod 3. Step 3: Lower the locking cap expansion device 2 so that it is completely seated on the cushion pad.

[0043] Step 4: Supply air to the air cylinder 232 to drive the clamping gripper drive rod 231 to move downward, so that the clamping gripper 23 is clamped and fixed with the cushion pad 1.

[0044] Step 5: Rotate the downward expansion operation head 26 by screwing the long rod 3, drive the nut pair to press the alignment screwing operation head 24, thereby press the expansion head 25, and further press the locking cap 11 to deform through the opening column 252, so that it is embedded into the opening of the head of the bolt 12, achieving the function of expansion and anti-loosening.

Claims

1. A device for relieving the remote expansion of a spacer locking cap of a thermal insulation sleeve, characterized by: It includes a locking cap expansion device and a long rod. The long rod is used for remote operation above the pool. The locking cap expansion device includes a positioning pin, a positioning cylinder, a clamping claw, an alignment and screwing operating head, an expansion head and a downward pressing expansion operating head.

2. A device for remotely tightening a thermal insulation sleeve to relieve a spacer lock cap according to claim 1, characterized in that: The positioning pin is cylindrical with a cone head guide, inserted into the installation process hole on the pad flange, and cooperates with the positioning cylinder to realize the positioning of the locking cap expansion device on the pad.

3. The device for remotely tightening the locking cap of a heat-insulating sleeve to relieve the spacer according to claim 1, characterized in that: The positioning cylinder is located at the center of the locking cap expansion device and is inserted into the center hole of the guide cylinder upper cover through the center hole of the cushion block to play a centering role.

4. The device for remotely tightening a heat-insulating sleeve to relieve a spacer lock cap according to claim 1, characterized in that: There are three clamping claws, which are evenly installed on the positioning cylinder through pins and can rotate around the pins to achieve fixation with the pad.

5. A device for remotely tightening a heat-insulating sleeve to relieve a spacer lock cap according to claim 4, characterized in that: The clamping and releasing of the clamping claw are realized by the clamping claw driving rod and the clamping cylinder. When air is supplied from the lower part of the clamping cylinder, the clamping claw driving rod moves upward, and the wedge-shaped surface of the clamping claw contacts and drives the clamping claw to retract and release; when air is supplied from the upper part of the clamping cylinder, the clamping claw driving rod moves downward, and the wedge-shaped surface of the clamping claw contacts and drives the clamping claw to be stretched, thereby achieving clamping and fixation with the inner conical surface of the pad.

6. The device for remotely tightening a heat-insulating sleeve to relieve a spacer locking cap according to claim 1, characterized in that: The upper end of the alignment and screwing operating head is a tapered outer square structure, which cooperates with the inner square of the long rod to play the role of a rotating tightening head.

7. The device for remotely tightening the locking cap of a heat-insulating sleeve to relieve the spacer according to claim 1, characterized in that: The expansion head includes a positioning hexagonal head and a notch column. The positioning hexagonal head is extended and retracted by the action of the upper spring force. The positioning hexagonal head cooperates with the inner hexagon of the bolt. The positioning of the notch column and the bolt notch is achieved through the positional relationship of the components of the expansion head.

8. A device for remotely tightening a heat-insulating sleeve to relieve a spacer lock cap according to claim 7, characterized in that: The downward pressure and expansion operating head is a rotating component, which is driven to rotate by a long rod. The lower end of the head is a threaded pair, which drives the pressure plate to move up and down by rotating the screw. When moving downward, the rotating expansion head is pressed down, and the notch column is pressed down to drive the locking cap to deform toward the notch of the bolt to achieve locking.

9. A method for relieving remote expansion of a spacer locking cap for a thermal insulation sleeve, characterized in that: The steps include: Step 1: Lower the locking cap expansion device and determine the position of the locking cap expansion device by matching the positioning pin with the positioning hole on the pad flange and the positioning cylinder with the center hole of the pad; Step 2: Observe the position of the positioning hexagonal head of the expansion head and the notch of the bolt head, and use the long rod to rotate and align the screw operating head so that the notch column is aligned with the notch of the bolt head; Step 3: Tighten the locking cap at the bottom to make it completely seated on the pad; Step 4: Supply air to the cylinder to drive the clamping claw drive rod to move downward, so that the clamping claw and the pad are clamped and fixed; Step 5: Use the long rod to screw down the expansion and tightening operating head, drive the nut pair down to align with the screwing operating head and press it down to tighten, and then squeeze the locking cap through the notch column to deform it and embed it into the notch of the bolt head, thereby expanding and preventing it from loosening.

Images