Embedded metal sealing ring dismounting device and method

Abstract

The invention belongs to the technical field of nuclear power reactor pressure vessel tools, and provides an embedded metal sealing ring dismantling device and method.The dismantling device comprises a tray, a plurality of stress pieces and an ejector rod; the multiple stress pieces are arranged at equal intervals in the circumferential direction of the tray. The side, facing the groove of the CRDM pipe base, of each stress piece is provided with an extending part, and each extending part is provided with a barb part protruding towards one side in the groove. When the embedded metal sealing ring is dismounted, the barb part of each stress piece corresponds to the part, protruding out of the groove, of the embedded metal sealing ring; the ejector rod is rotatably arranged in the center of the tray in a penetrating mode, and the tray can be driven to move in the axial direction by rotating the ejector rod. According to the method, the difficulty in dismantling the conical sealing ring embedded in the CRDM tube socket can be solved, the dismantling quality of the conical sealing ring embedded in the CRDM tube socket of the EPR type nuclear power reactor pressure vessel top cover can be guaranteed, and technical support is provided for safe operation of nuclear power.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power reactor pressure vessel tooling, and in particular relates to an embedded metal sealing ring removal device and method. Background Art

[0002] The sealing of the control rod drive mechanism tube seat (CRDM tube seat for short) of the pressure vessel top cover of the EPR type nuclear power reactor adopts a flange structure, which generally includes an upper flange and a flange interface set at the port of the CRDM tube seat. The upper flange and the CRDM tube seat are sealed by an inner and outer conical metal sealing ring structure to meet the sealing requirements of the CRDM tube seat. Among them, the inner and outer conical metal sealing rings between the upper flange and the CRDM tube seat are embedded structures. When the upper flange and the CRDM tube seat are sealed and assembled, the inner and outer conical sealing rings will be pressed tightly, causing the conical metal sealing rings to deform.

[0003] When it is necessary to remove the inner and outer conical metal sealing rings, due to the thin wall of the conical metal sealing ring and the strong plasticity of the stainless steel material, it is difficult to remove after being embedded in the sealing groove of the flange on the CRDM tube seat. The removal efficiency is low and it is easy to damage the groove sealing surface of the CRDM tube seat. The commonly used removal methods in the prior art include force removal method and processing removal method. Among them, the force removal method is to forcefully pull a certain cross section of the metal sealing ring to deform it so that it is separated from the CRDM tube seat groove; the processing removal method is to process the metal sealing ring to make it thinner so that the embedding force with the CRDM tube seat groove is reduced and separated. However, the above removal methods all have certain limitations. Due to limited space and small clamping force point surface, the strong removal method is easy to damage the CRDM tube seat groove sealing surface, and the local force is uneven during removal, which is easy to cause local extrusion of the CRDM tube seat groove sealing surface, resulting in squeeze damage to the sealing surface. The machining removal method is subject to the influence of equipment. Each CRDM tube seat needs to be individually processed and aligned, which is inconvenient to operate and has low efficiency. In addition, the metal sealing ring is easy to rotate after becoming thinner, and it may also scratch the sealing surface of the CRDM tube seat groove. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an embedded metal sealing ring removal device, which can solve the problem of removing the conical sealing ring embedded in the CRDM tube seat, which is beneficial to ensuring the removal quality of the embedded conical metal sealing ring of the CRDM tube seat of the top cover of the EPR reactor type nuclear power reactor pressure vessel, and provides technical support for the safe operation of nuclear power.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] An embedded metal sealing ring removal device comprises a tray, a plurality of force-bearing members and a push rod;

[0007] The plurality of force-bearing members are arranged at equal intervals along the circumferential direction of the tray; each of the force-bearing members is provided with a protruding portion that can extend to the groove on one side of the groove facing the groove of the CRDM tube seat, and the protruding portion is provided with a barb portion that protrudes toward one side of the groove; when the embedded metal sealing ring is removed, the barb portion of each of the force-bearing members corresponds to the portion of the embedded metal sealing ring that protrudes from the groove;

[0008] The push rod is rotatably arranged in the center of the tray, and rotating the push rod can cause the tray to move axially.

[0009] In a preferred embodiment of the present invention, the push rod is provided with an external thread structure; a threaded through hole is provided at the center of the tray; and the external thread structure cooperates with the threaded through hole.

[0010] Preferably, each of the force-bearing members is connected to the top surface of the tray, and one end of the force-bearing member away from the center of the tray radially extends out of the tray, and the protruding portion is located at the end of the force-bearing member away from the center of the tray.

[0011] Preferably, each of the force-bearing members is provided with an oblong first hole, and the length direction of the first hole extends radially; the tray is provided with a plurality of second holes that match the first holes of each of the force-bearing members;

[0012] A locking assembly is provided between each of the first holes and each of the second holes to lock and fix the force-bearing member on the tray.

[0013] Preferably, the locking assembly comprises a bolt and a nut; the bolt passes through the first hole and the second hole and is locked with the nut.

[0014] Preferably, a clamping platform is provided on one side of the force-bearing member close to the tray.

[0015] In a preferred embodiment of the present invention, a contact portion between the barb portion and the embedded metal sealing ring is provided with a rounded corner.

[0016] According to a preferred embodiment of the present invention, the outer side profile of the barb portion is arc-shaped and matches the groove.

[0017] Another object of the present invention is to provide a method for removing an embedded metal sealing ring using the above-mentioned removal device.

[0018] A method for removing an embedded metal sealing ring comprises the following steps:

[0019] S1. Remove the upper flange on the CRDM tube seat to expose the groove on the CRDM tube seat. At this time, the pressed embedded metal sealing ring is embedded and fastened on the CRDM tube seat.

[0020] S2. Install a plug in the hollow part of the CRDM tube seat. Using the hollow structure of the CRDM tube seat, place the plug in the hollow part, and the plug cannot move into the CRDM tube seat in the axial direction.

[0021] S3. Place the tray on the end face of the CRDM tube seat, allow the push rod to be supported on the plug, and adjust the radial position of each force-bearing member so that the barb portion of each force-bearing member is inserted into the groove of the CRDM tube seat and the barb portion abuts against the side of the groove, and lock and fix the position of each force-bearing member so that the barb portion corresponds to the part of the embedded metal sealing ring;

[0022] S4. Rotate the ejector rod to cause the tray and each force-bearing member to move axially upward synchronously; the barb portion of each force-bearing member hooks up the embedded metal sealing ring until it is completely separated from the CRDM pipe seat, and the removal is completed.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The embedded metal sealing ring removal method of the present invention solves the problem of removing the embedded conical metal sealing ring of the CRDM tube seat, ensures the installation and removal quality of the embedded conical metal sealing ring of the CRDM tube seat of the EPR reactor type nuclear power reactor pressure vessel top cover, and provides technical support for the safe operation of nuclear power. Specifically, during removal, each force-bearing member moves axially synchronously, so that the force of the barb part in contact with different positions of the embedded metal sealing ring remains balanced, and multiple points are in step, which is conducive to the smooth removal of the embedded metal sealing ring and reduces the impact of damage to it. The cooperation between the push rod and the tray can quickly complete the removal work by rotating the push rod. The operation is simple and convenient, and it is particularly suitable for the removal of the metal sealing ring on the CRDM tube seat, and it is highly specialized. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0026] Figure 1 Schematic diagram of the sealing structure between the upper flange and the CRDM pipe seat.

[0027] Figure 2 for Figure 1 A is an enlarged view of the middle image.

[0028] Figure 3 It is a top view of the embedded metal sealing ring removal device of the present invention.

[0029] Figure 4It is a side view of the embedded metal sealing ring removal device of the present invention.

[0030] Figure 5 for Figure 4 Side view of the load-bearing member in FIG.

[0031] Figure 6 It is a schematic diagram of assembling the embedded metal sealing ring removal device of the present invention on the CRDM tube seat.

[0032] Figure 7 for Figure 6 An enlarged view of B (the barb portion does not abut the side of the groove at this time).

[0033] in:

[0034] 1-upper flange, 2-CRDM pipe seat, 3-groove, 4-external sealing ring, 5-inner sealing ring, 6-tray, 7-top rod, 8-force bearing member, 9-extending part, 10-barb part, 11-card table, 12-first hole, 13-second hole. DETAILED DESCRIPTION

[0035] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention, and the embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] Example 1

[0038] See also Figure 1-Figure 7The embedded metal sealing ring on the CRDM tube seat 2 is only 1.25mm thick and conical, while the groove 3 on the CRDM tube seat 2 is 6.8mm wide. The embedded conical metal sealing ring is used once under the mutual compression of the upper flange 1 and the port of the CRDM tube seat 2. The conical metal sealing ring will be deeply embedded in the conical surface of the groove 3. The metal ring is generally made of austenitic stainless steel with high strength and toughness. After deformation, the metal sealing ring fits tightly with the sealing side, and the conical metal sealing ring only extends 0.5mm from the side of the groove 3. Therefore, if conventional strong demolition or processing demolition methods are used for demolition, it will be difficult to implement and easy to cause damage to the CRDM tube seat 2 and the metal sealing ring, especially the impact on the sealing surface.

[0039] This embodiment designs an embedded metal sealing ring removal device for the removal of the embedded metal sealing ring, including a tray 6, a plurality of force-bearing members 8 and a push rod 7. Among them, the plurality of force-bearing members 8 are arranged at equal intervals along the circumferential direction of the tray 6, and the equal spacing of the plurality of force-bearing members 8 is conducive to making the embedded metal sealing ring more uniformly stressed during removal, more easily detached from the CRDM tube seat 2, and preventing it from deforming as much as possible; preferably, this embodiment uses four force-bearing members 8. Furthermore, each force-bearing member 8 is provided with a protruding portion 9 that can extend to the groove 3 on one side of the groove 3 of the CRDM tube seat 2, and the protruding portion 9 is provided with a barb portion 10 that protrudes to one side of the groove 3; when removing the embedded metal sealing ring, the barb portion 10 of each force-bearing member 8 corresponds to the portion of the embedded metal sealing ring protruding from the groove 3. The push rod 7 of this embodiment can be rotatably penetrated in the center of the tray 6, and rotating the push rod 7 can cause the tray 6 to move axially.

[0040] Specifically, the embedded metal sealing ring removal device of this embodiment is used to remove the outer sealing ring 4 on the CRDM tube seat 2, so the barb portion 10 on the force-bearing member 8 protrudes radially outward. When the inner sealing ring 5 on the CRDM tube seat 2 is removed, the barb portion 10 on the force-bearing member 8 can be designed to protrude radially inward, so that it can correspond to the inner sealing ring 5. Furthermore, in theory, two barbs 10 can also be set on the force-bearing member 8, protruding radially inward and outward respectively, and these two barbs 10 correspond to the inner and outer sealing rings at the same time, so that they can be removed simultaneously.

[0041] Furthermore, in order to better realize the circumferential movement of the tray 6 and the multiple force-bearing members 8 driven by the push rod 7, the present embodiment is provided with an external thread structure on the push rod 7; a threaded through hole is provided at the center of the tray 6; and the external thread structure cooperates with the threaded through hole. The push rod 7 and the tray 6 are threadedly matched to realize the relative axial movement of the two. Specifically, the push rod 7 can be screwed to move axially downward, thereby using the threaded matching method to promote the tray 6 and the multiple force-bearing members 8 arranged on the tray 6 to move upward synchronously, and then the embedded metal sealing ring is pushed upward under the action of each barb 10, thereby separating it from the CRDM tube seat 2 and completing the removal work.

[0042] In addition, in addition to the threaded matching method, the push rod 7 and the tray 6 of this embodiment can also adopt the matching method of guide grooves and guide pillars to achieve relative axial movement of the two. For example, a guide groove that extends spirally along the peripheral wall of the push rod 7 can be provided on the outer wall of the push rod 7, a through hole is provided at the center of the tray 6, and a guide pillar is provided on the inner wall of the through hole, and the guide pillar is matched and embedded in the guide groove. In this way, by rotating the push rod 7, the tray 6 and the multiple force-bearing members 8 can be urged to move axially upward by utilizing the guiding matching of the guide groove and the guide pillar, thereby achieving the purpose of finally lifting the embedded metal sealing inner ring.

[0043] Furthermore, each force-bearing member 8 of the present embodiment is connected to the top surface of the tray 6, and the end of the force-bearing member 8 away from the center of the tray 6 radially extends out of the tray 6, and the extension portion 9 is located at the end of the force-bearing member 8 away from the center of the tray 6. The force-bearing member 8 is arranged on the top surface of the tray 6, which facilitates the assembly and adjustment of the force-bearing member 8 and the tray 6 and reduces the difficulty of assembly. At the same time, each force-bearing member 8 is provided with an oblong first hole 12, and the length direction of the first hole 12 extends radially; the tray 6 is provided with a plurality of second holes 13 that cooperate with the first holes 12 of each force-bearing member 8; a locking assembly is provided between each first hole 12 and each second hole 13 to lock and fix the force-bearing member 8 on the tray 6. The locking assembly of the present embodiment adopts bolts and nuts; the bolts pass through the first hole 12 and the second hole 13 and are locked with the nuts. Furthermore, the locking assembly can also adopt other embodiments in the prior art, mainly to be able to lock and fix the force-bearing member 8 and the tray 6.

[0044] In this embodiment, an oblong first hole 12 is provided on the force-bearing member 8, so that the force-bearing member 8 has a certain adjustment space in the radial direction, so that the position adjustment between each force-bearing member 8 is more flexible and convenient, which is conducive to accurately placing the hook portion 10 on the side wall of the groove 3 to ensure that it can correspond to the embedded metal sealing ring, which is conducive to improving the removal effect; and the radial extension distance of each force-bearing member 8 can be adjusted to adapt to embedded metal sealing rings of different radius sizes.

[0045] Furthermore, a clamping platform 11 is provided on one side of the force-bearing member 8 close to the tray 6. By providing the clamping platform 11, the force-bearing member 8 can be restricted and positioned when it is adjusted radially inward to the limit position. Furthermore, the side surface of the clamping platform 11 of this embodiment is arc-shaped, corresponding to the side surface of the circular tray 6, so that the matching degree is better.

[0046] The contact area between the barb portion 10 and the embedded metal sealing ring of this embodiment is provided with a rounded corner, such as Figure 5 Specifically, the upper and lower corners of the barb 10 in this embodiment are rounded, which can avoid the sharp corners of the barb 10 and the sealing ring and the side of the groove 3 from being squeezed and damaged, thereby protecting the integrity of the CRDM tube seat 2 structure and the sealing ring.

[0047] Furthermore, the outer side profile of the barb portion 10 of this embodiment is arc-shaped and matches the groove 3. In this way, the barb portion 10 can be better fitted against the inner side of the groove 3 during the removal process, and the barb portion 10 of each force-bearing member 8 can be more consistent with the corresponding part of the embedded metal sealing ring, thereby facilitating the increase of the contact area with the sealing ring, making the force more balanced, making removal easier, and protecting the original structure of the embedded metal sealing ring.

[0048] In addition, in order to make the overall structure of the device more coordinated and better fit with the CRDM tube seat 2, the tray 6 is also set to be circular in this embodiment.

[0049] This embodiment also provides a method for removing the embedded metal sealing ring using the above-mentioned removal device. Specifically, it includes the following steps:

[0050] S1. Remove the upper flange 1 on the CRDM tube base 2 to expose the groove 3 on the CRDM tube base 2. At this time, the pressed embedded metal sealing ring is embedded and fastened on the CRDM tube base 2.

[0051] S2. Install a plug in the hollow part of the CRDM tube socket 2; utilize the hollow structure of the CRDM tube socket 2 to place the plug in the hollow part, and the plug cannot move toward the inside of the CRDM tube socket 2 in the axial direction; specifically, the hollow structure of the CRDM tube socket 2 is provided with a clamping position, which can be used to prevent the plug from continuing to move axially inward after being placed in, and the plug provides support and leverage for the push rod 7 when it is removed.

[0052] S3, place the tray 6 on the end surface of the CRDM tube seat 2, let the push rod 7 support on the plug, and adjust the radial position of each force-bearing member 8 at the same time, so that the barb portion 10 of each force-bearing member 8 is inserted into the groove 3 of the CRDM tube seat 2 and the barb portion 10 abuts against the side of the groove 3, and each force-bearing member 8 is locked and fixed on the tray 6 by a locking assembly, and the barb portion 10 at this time corresponds to the part of the embedded metal sealing ring;

[0053] S4, rotating the ejector rod 7, causing the tray 6 and each force-bearing member 8 to move axially upward synchronously; the barb portion 10 of each force-bearing member 8 hooks up the embedded metal sealing ring until it is completely separated from the CRDM tube seat 2, and the removal is completed.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An embedded metal sealing ring removal device, characterized in that: It includes a tray, a plurality of load-bearing members and a top rod; The plurality of force-bearing members are arranged at equal intervals along the circumferential direction of the tray; each of the force-bearing members is provided with a protruding portion that can extend to the groove on one side of the groove facing the groove of the CRDM tube seat, and the protruding portion is provided with a barb portion that protrudes toward one side of the groove; when the embedded metal sealing ring is removed, the barb portion of each of the force-bearing members corresponds to the portion of the embedded metal sealing ring that protrudes from the groove; The push rod is rotatably arranged in the center of the tray, and rotating the push rod can cause the tray to move axially.

2. The embedded metal sealing ring removal device according to claim 1, characterized in that: The top rod is provided with an external thread structure; the center of the tray is provided with a threaded through hole; the external thread structure cooperates with the threaded through hole.

3. The embedded metal sealing ring removal device according to claim 1, characterized in that: Each of the force-bearing members is connected to the top surface of the tray, and one end of the force-bearing member away from the center of the tray radially extends out of the tray, and the protruding portion is located at the end of the force-bearing member away from the center of the tray.

4. The embedded metal sealing ring removal device according to claim 3, characterized in that: Each of the force-bearing members is provided with an oblong first hole, the length direction of which extends radially; the tray is provided with a plurality of second holes that match the first holes of each of the force-bearing members; A locking assembly is provided between each of the first holes and each of the second holes to lock and fix the force-bearing member on the tray.

5. The embedded metal sealing ring removal device according to claim 4, characterized in that: The locking assembly includes a bolt and a nut; the bolt passes through the first hole and the second hole and is locked with the nut.

6. The embedded metal sealing ring removal device according to claim 4, characterized in that: A clamping platform is provided on one side of the force bearing member close to the tray.

7. The embedded metal sealing ring removal device according to any one of claims 1 to 6, characterized in that: The contact portion between the barb portion and the embedded metal sealing ring is provided with a rounded corner.

8. The embedded metal sealing ring removal device according to any one of claims 1 to 6, characterized in that: The outer side profile of the barb portion is arc-shaped and matches the groove.

9. A method for removing an embedded metal sealing ring using the embedded metal sealing ring removal device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Remove the upper flange on the CRDM tube seat to expose the groove on the CRDM tube seat. At this time, the pressed embedded metal sealing ring is embedded and fastened on the CRDM tube seat. S2. Install a plug in the hollow part of the CRDM pipe socket; By utilizing the hollow structure of the CRDM tube seat, a plug is placed in the hollow portion, and the plug cannot move into the CRDM tube seat in the axial direction; S3. Place the tray on the end face of the CRDM tube seat, allow the push rod to be supported on the plug, and adjust the radial position of each force-bearing member so that the barb portion of each force-bearing member is inserted into the groove of the CRDM tube seat and the barb portion abuts against the side of the groove, and lock and fix the position of each force-bearing member so that the barb portion corresponds to the part of the embedded metal sealing ring; S4. Rotate the ejector rod to cause the tray and each force-bearing member to move axially upward synchronously; the barb portion of each force-bearing member hooks up the embedded metal sealing ring until it is completely separated from the CRDM pipe seat, and the removal is completed.

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