Thread protector for a throttling assembly of a high temperature gas cooled reactor steam generator

Abstract

The application discloses a kind of high temperature gas cooled reactor steam generator throttle component thread protection devices, it is characterized in that, including the positioning block for with the detachable connection of the throttle component end, and clamping piece and protection piece are set on positioning block, the clamping piece is elastic piece, for the end of the throttle component is releasably clamped and fixed with the positioning block;The protection piece is tungsten steel sheet, for shielding the outer thread of throttle component, to isolate the influence of welding process to outer thread.The high temperature gas cooled reactor steam generator throttle component thread protection device disclosed in the application is easy to operate, fundamentally protects the throttle component thread, improves operation efficiency.

Description

Technical Field

[0001] This invention relates to a thread protection device for a throttling assembly of a high-temperature gas-cooled reactor steam generator, belonging to the field of nuclear power equipment manufacturing technology. Background Technology

[0002] The high-temperature gas-cooled reactor steam generator is a core heat exchange device in advanced fourth-generation nuclear power units. During operation, cooling water enters numerous heat exchange tubes from the tube sheet at the bottom of the steam generator. Heated by high-temperature helium circulating inside the equipment, it forms high-temperature steam, which eventually flows out from the upper tube sheet to drive the turbine to generate electricity.

[0003] In order to precisely control the inlet water flow into each heat exchange tube, after the steam generator equipment is manufactured as a whole, it needs to be placed vertically and operated by the operator from the bottom end cap to install the throttling component 2 at the end of each heat exchange tube 6 at the tube sheet 7. Figure 8 , Figure 9 The installation structure of the throttling assembly is shown. The inner wall of the heat exchange tube is machined with internal threads, and the external threads of the throttling assembly are screwed into the tube hole to mate with them. It needs to be pre-tightened according to the preset torque requirements. Subsequently, an anti-loosening sleeve 3 is fitted onto the outside of the throttling assembly, and all the throttling assemblies are structurally fixed together by a common positioning plate 4 to ensure that the throttling assembly will not loosen or be damaged due to fluid impact during subsequent operation.

[0004] During installation, after the positioning plate is in place, it needs to be evenly welded to each anti-loosening sleeve 3 at four circumferential positions. Then, nuts 5 are screwed into the throttling components at designated locations to secure them to the throttling components as a whole.

[0005] In actual manufacturing, the tube sheet end has up to 665 heat exchange tubes and corresponding throttling components. According to design requirements, 49 of these throttling component locations require additional reinforcement with nuts. At these nut locations, short anti-loosening sleeves 32 are used, with a height lower than the upper surface of the positioning hole plate. Correspondingly, the positioning hole plate has weld grooves of a certain depth for these short anti-loosening sleeves 32. The installation process requires first butt welding the short anti-loosening sleeves 32 to the positioning hole plate within the grooves, and then screwing the nuts into the throttling components.

[0006] like Figure 10As shown, for other locations where no nuts are installed, the anti-loosening sleeve used is a long anti-loosening sleeve with a height higher than the upper surface of the positioning hole plate, forming a long anti-loosening sleeve welding structure H1 with the positioning hole plate. This welding position is far from the thread of the throttling component and has a good operating field of vision, making the welding relatively easy. However, there are significant technical challenges when welding the short anti-loosening sleeve to the short anti-loosening sleeve welding structure H2 of the positioning hole plate. This weld is located in the groove of the positioning hole plate, and its edge is extremely close to the external thread of the throttling component, with an actual distance of only about 2.8 mm. When performing this welding process, the operator is in an overhead welding position, with a limited operating angle and narrow welding space, making it difficult to precisely control the width of the weld pool. Even when using a fine welding wire with a diameter of only φ1 mm for manual tungsten inert gas welding, the minimum width of the weld pool that the operator can control is usually only 3~4 mm. Therefore, during the welding process, the molten pool is very likely to stick to the threads of the throttling component. The high-temperature electric arc and molten pool can easily cause melting and burning of the precision threads. Once the threads are damaged, they cannot be reused, resulting in the scrapping of the entire expensive nickel-based alloy throttling component with extremely high machining precision requirements, causing huge economic losses and project delays.

[0007] Therefore, it is necessary to conduct in-depth research on the thread protection of the throttling assembly of the steam generator in the high-temperature gas-cooled reactor of nuclear power products during the welding process in order to solve the above problems. Summary of the Invention

[0008] To overcome the above problems, in-depth research was conducted, and a thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator was proposed. The device includes a positioning block 11 for detachable connection to the end of the throttling assembly, and a clamping member 12 and a protective member 13 disposed on the positioning block 11. The clamping member 12 is an elastic member, used to releasably clamp and fix the positioning block 11 to the end of the throttling assembly; The protective component 13 is a tungsten carbide sheet used to shield the external threads of the throttling assembly to isolate the welding process from the influence of the external threads.

[0009] In a preferred embodiment, the positioning block 11 has a mounting slot 111, the outline of which is adapted to the outer contour of the throttling assembly end.

[0010] In a preferred embodiment, a protective positioning step 112 is further provided on the positioning block 11 to provide a flat support surface for supporting the protective component 13.

[0011] In a preferred embodiment, there are two positioning steps 112, which are symmetrically arranged on both sides of the positioning block 11. The distance between the supporting surfaces of the two positioning steps matches the outer diameter of the external thread of the throttling component, so that after the device is installed, the protective member fixed on the positioning step 112 can be close to the crest of the thread.

[0012] In a preferred embodiment, the clamping member 12 is an elastic clamp.

[0013] In a preferred embodiment, at least one welding notch 131 is designed on the edge portion of the protective member 13, the welding notch 131 being a notch recessed inward from the edge of the protective member 13.

[0014] In a preferred embodiment, the positioning block is filled by welding at the welding notch 131. The molten welding wire metal fills the notch and fuses with the positioning block base material. The plug weld metal body 132 formed after cooling and solidification firmly rivets the tungsten sheet to the positioning block.

[0015] In a preferred embodiment, the thickness of the protective element 13 is 0.2-0.4 mm.

[0016] This invention also discloses a method for installing a throttling assembly in a high-temperature gas-cooled reactor steam generator, using one of the aforementioned thread protection devices for the throttling assembly of a high-temperature gas-cooled reactor steam generator, comprising the following steps: S1. At the nozzle of each heat exchange tube 6 at the end of the tube sheet 7, install a throttling assembly 2 and an anti-loosening sleeve, wherein the anti-loosening sleeve includes a long anti-loosening sleeve 31 and a short anti-loosening sleeve 32, and weld the long anti-loosening sleeve 31 to the positioning hole plate. S2. For short anti-loosening sleeves 32 that require welding, weld them after installing the throttling component thread protection device 1 on the corresponding throttling component 2. S3. After removing the thread protection device of the throttling component, install a nut at the end of the throttling component 2.

[0017] In a preferred embodiment, S2 includes the following sub-steps: S21. Align the mounting slot 111 of the throttling component thread protection device 1 with the end of the throttling component 2 and push it upward, so that the clamping member 12 clamps the throttling component thread protection device 1 on the throttling component 2, and the protection member 13 is located between the welding area of ​​the short anti-loosening sleeve 32 and the external thread of the throttling component 2. S22. Weld the short anti-loosening sleeve 32 to the side near the protective component 13 to fix the short anti-loosening sleeve 32 to the positioning hole plate, and complete the first welding. S23. Rotate the thread protection device 1 of the throttling component 90 degrees and weld the short anti-loosening sleeve 32 to the side near the protective part 13 to complete the second welding.

[0018] The beneficial effects of this invention include: (1) By using high-temperature resistant and anti-adhesion thin tungsten sheets as an isolation barrier, the welding pool and arc heat that are only 2.8 mm away from the external thread of the throttling component are effectively blocked, thus fundamentally avoiding the problem of thread damage caused by weld pool adhesion or heat effect. (2) It has a compact structure and is easy to assemble and disassemble. It can quickly clamp and disassemble with the end of the throttling component through the clamping parts. It is easy to operate and does not require additional tools, which improves the efficiency of on-site operation. (3) It has good process compatibility and does not require any changes to the original welding process, welding materials or operating procedures. It can be used as an additional auxiliary tooling and is easy to promote and apply in the existing production process. Attached Figure Description

[0019] Figure 1 A schematic diagram of the thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 2 A schematic diagram of the thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 3 A schematic diagram of the protective component of the thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 4 A schematic diagram of the positioning block structure of the thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 5 A schematic diagram of the installation of a thread protection device for a throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 6 A schematic diagram of the installation of a thread protection device for a throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention is shown. Figure 7 A rear-view view showing the installation of the thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to a preferred embodiment of the present invention. Figure 8 A schematic diagram of the throttling assembly, fixtures, and heat exchange tube installation structure of a high-temperature gas-cooled reactor steam generator is shown. Figure 9 A schematic diagram of the throttling assembly, fixtures, and heat exchange tube installation structure of a high-temperature gas-cooled reactor steam generator is shown. Figure 10This diagram shows the throttling assembly, fixtures, and heat exchange tube installation structure of a high-temperature gas-cooled reactor steam generator.

[0020] Symbol Explanation 1-Throttling component thread protection device; 2-Throttling components; 3- Anti-loosening sleeve; 4-Positioning hole plate; 5-Nuts; 6-Heat exchange tube; 7-Tube sheet; 11-Location block; 12-Clamping component; 13-Protective components; 31-Long anti-loosening sleeve; 32-Short anti-loosening sleeve; 111 - Installing card slot; 112 - Positioning step; 131 - Welding notch; 132 - Plug weld metal body; H1 - Long anti-loosening sleeve welding structure; H2 - Short anti-loosening sleeve welding structure. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0022] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0023] According to the present invention, a thread protection device for a throttling assembly in a high-temperature gas-cooled reactor steam generator is provided to protect the external threads of the throttling assembly inserted into the heat exchange tube when a short anti-loosening sleeve is welded to a positioning orifice plate. Figure 1 As shown, the device includes a positioning block 11 for detachable connection to the end of the throttling assembly, and a clamping member 12 and a protective member 13 disposed on the positioning block 11. The clamping member 12 is an elastic member, used to releasably clamp and fix the positioning block 11 to the end of the throttling assembly; The protective component 13 is a tungsten carbide sheet used to shield the external threads of the throttling assembly to isolate the welding process from the influence of the external threads.

[0024] In a preferred embodiment, such as Figure 3The positioning block 11 has a mounting slot 111, the outline of which is adapted to the outer outline of the end of the throttling component, so that the positioning block 11 can be quickly inserted into the end of the throttling component.

[0025] Preferably, a protective positioning step 112 is also provided on the positioning block 11 to provide a flat support surface to support the protective component 13.

[0026] More preferably, there are two positioning steps 112, symmetrically arranged on both sides of the positioning block 11. The distance between the support surfaces of the two positioning steps matches the outer diameter of the external thread of the throttling component, so that after the device is installed, the protective part fixed on the positioning step 112 can be close to the crest of the thread, providing effective isolation, while avoiding scratch damage to the thread when inserting or removing the device.

[0027] In a preferred embodiment, the clamping member 12 is at least a pair of elastic clamping pieces, preferably made of spring steel or stainless steel sheet. Each clamping piece has a fixed end and a free end. The fixed end is fixed to the side of the positioning block by spot welding, riveting or threaded connection, etc., and the free end is bent or tilted inward so that an opening is formed between the free ends of the two opposite clamping pieces.

[0028] Furthermore, the minimum spacing of this opening in its natural state, i.e., the clamping distance, is designed to be smaller than the diameter of the end of the throttling assembly, such as... Figure 2 As shown. When the positioning block is inserted along the end of the throttling assembly, the sidewall of the end forces the free ends of the two clamping plates to elastically deform and open outward. The opened clamping plates then generate a continuous elastic clamping force pointing inward, thereby firmly clamping the entire device onto the throttling assembly, as shown. Figure 5 As shown.

[0029] Tungsten steel has a high melting point and does not fuse or adhere to other metals, making it commonly used as the tip of a welding torch. In this invention, tungsten steel is used as a protective component to effectively block the temperature of the molten pool and the high-temperature arc, thereby isolating the welding process from the external threads of the throttling assembly. Figure 6 , Figure 7 As shown.

[0030] However, tungsten steel is brittle and cannot be machined or withstand external forces, otherwise it will break. Fixing it to the positioning block is a challenge, as traditional bonding or welding methods cannot achieve this.

[0031] In a preferred embodiment, such as Figure 4As shown, at least one welding notch 131 is designed on the edge portion of the protective member 13. The welding notch 131 is a notch that is recessed inward from the edge of the protective member 13, such as a rectangular notch, a semi-circular notch, or a V-shaped notch.

[0032] According to the present invention, the positioning block is filled by welding at the welding notch 131 using a welding torch. The molten welding wire metal fills the notch and fuses with the positioning block base material. The plug weld metal body 132 formed after cooling and solidification acts as a "rivet" to firmly rivet the tungsten sheet to the positioning block. This fixing method does not apply destructive stress to the tungsten sheet itself, and the fixing structure is compact and does not increase the radial or axial dimensions of the device, ensuring its applicability in confined spaces. It completely avoids applying any mechanical stress (such as clamping or pressing) to the tungsten sheet that may cause it to break. At the same time, it does not require additional screws, pressure plates or other fixing parts, making the entire device more integrated and more compact.

[0033] In a preferred embodiment, the thickness of the protective element 13 is 0.2-0.4 mm, preferably 0.3 mm. This thickness is selected empirically and can effectively block the temperature of the molten pool and the high-temperature arc. It makes full use of its high melting point and anti-adhesion physical properties, allowing it to be inserted into a narrow gap of only 2.8 mm to form an effective physical barrier. This ensures that when working in a narrow space, the device itself will not obstruct the welding field of vision or interfere with the operating angle of the welding torch.

[0034] According to the present invention, the outer contour of the protective member 13 can be precisely processed by wire cutting process, and the whole is rectangular or other shapes that are easy to install, preferably rectangular.

[0035] Furthermore, there are two protective components 13, which are respectively disposed on two protective component positioning steps 112.

[0036] This invention also discloses a method for installing a throttling assembly in a high-temperature gas-cooled reactor steam generator, comprising the following steps: S1. At the nozzle of each heat exchange tube 6 at the end of the tube sheet 7, install a throttling assembly 2 and an anti-loosening sleeve, wherein the anti-loosening sleeve includes a long anti-loosening sleeve 31 and a short anti-loosening sleeve 32, and weld the long anti-loosening sleeve 31 to the positioning hole plate. S2. For short anti-loosening sleeves 32 that require welding, weld them after installing the throttling component thread protection device 1 on the corresponding throttling component 2. S3. After removing the thread protection device of the throttling component, install a nut at the end of the throttling component 2.

[0037] S2 includes the following sub-steps: S21. Align the mounting slot 111 of the throttling component thread protection device 1 with the end of the throttling component 2 and push it upward, so that the clamping member 12 clamps the throttling component thread protection device 1 on the throttling component 2. At this time, the protection member 13 is located between the welding area of ​​the short anti-loosening sleeve 32 and the external thread of the throttling component 2. S22. Weld the short anti-loosening sleeve 32 to the side near the protective component 13 to fix the short anti-loosening sleeve 32 to the positioning hole plate, and complete the first welding. S23. Rotate the thread protection device 1 of the throttling component 90 degrees and weld the short anti-loosening sleeve 32 to the side near the protective part 13 to complete the second welding.

[0038] According to the present invention, in S21, during the process of pushing in the thread protection device 1 of the throttling component, the end sidewall of the throttling component 2 will squeeze the free ends of the clamping members 12 on both sides of the positioning block 11, forcing them to undergo elastic deformation and open outward.

[0039] When the mounting slot 111 of the positioning block 11 is fully engaged with the end of the throttling component 2, the clamping parts 12 on both sides are reset under their own elastic force, thereby firmly clamping the end of the throttling component 2 and completing the installation and fixing of the thread protection device 1 of the throttling component.

[0040] At this time, the relative positional relationship between the thread protection device 1 of the throttling component and the component to be welded is as follows: the positioning block 11 is attached to the end of the throttling component 2; the protective member 13 fixed on both sides of the positioning block 11 has its inner side adjacent to or slightly in contact with the external thread of the throttling component 2, while its outer side abuts against the end face of the short anti-loosening sleeve 32. Thus, the protective member 13 establishes a physical isolation barrier between the area to be welded between the short anti-loosening sleeve 32 and the positioning hole plate 4 and the external thread of the throttling component 2 in the first circumferential direction.

[0041] In S22, during the welding process, the high temperature heat generated by the welding arc and the molten pool formed are effectively blocked by the protective component 13 located between it and the thread. Because the protective component 13 has an extremely high melting point and anti-metal adhesion properties, the molten pool will not melt through it, nor will it pass through the isolation barrier and adhere to or cause thermal damage to the external thread of the throttling component 2.

[0042] In step S23, after the welding of the two seams in the first direction is completed, the operator holds the installed thread protection device 1 of the throttling component and applies a certain rotational force to overcome the clamping friction of the clamping member 12, rotating the entire device 90 degrees. During the rotation and after it is in place, the thread protection device 1 of the throttling component remains firmly clamped to the end of the throttling component 2 by the clamping member 12. At this time, the positions of the two protective members 13 on both sides change accordingly, moving to the second direction which is basically perpendicular to the first direction.

[0043] In step S3, after the weld has completely cooled, the operator pulls the thread protection device 1 of the throttling component downwards, causing the throttling component 2 to elastically open again, thereby removing the entire device from the throttling component 2. At this point, all four circumferential welds of the short anti-loosening sleeve 32 and the positioning hole plate have been safely and reliably welded, and the external thread of the throttling component 2 has not been damaged.

[0044] Finally, the operator takes a nut, screws it onto the end thread of the welded throttling component 2, and tightens it to the specified torque to complete the final fixation of the throttling component 2 at this position.

[0045] The above method solves a key technical problem in the manufacturing process of high-temperature gas-cooled reactor steam generators without changing the original welding process or affecting the operating space and field of vision, effectively ensuring the manufacturing quality of expensive throttling components and the overall operational safety of the equipment.

[0046] In the description of this invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. A thread protection device for a throttling assembly of a high-temperature gas-cooled reactor steam generator, characterized in that, It includes a positioning block (11) for detachable connection with the end of the throttling assembly, and a clamping member (12) and a protective member (13) disposed on the positioning block (11). The clamping member (12) is an elastic member used to releasably clamp and fix the positioning block (11) to the end of the throttling assembly; The protective component (13) is a tungsten carbide sheet used to shield the external thread of the throttling assembly to isolate the influence of the welding process on the external thread.

2. The thread protection device for the throttling assembly of the high-temperature gas-cooled reactor steam generator according to claim 1, characterized in that, The positioning block (11) has a mounting slot (111) whose outline shape is adapted to the outer outline of the throttling component end.

3. The thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 1, characterized in that, A protective element positioning step (112) is also provided on the positioning block (11) to provide a flat support surface to support the protective element (13).

4. The thread protection device for the throttling assembly of the high-temperature gas-cooled reactor steam generator according to claim 3, characterized in that, The positioning step (112) has two, which are symmetrically arranged on both sides of the positioning block (11). The distance between the support surfaces of the two positioning steps matches the outer diameter of the external thread of the throttling component, so that after the device is installed, the protective part fixed on the positioning step (112) can be close to the top of the thread.

5. The thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 1, characterized in that, The clamping element (12) is an elastic clamp.

6. The thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 1, characterized in that, At least one welding notch (131) is designed on the edge portion of the protective member (13), the welding notch (131) being a notch recessed inward from the edge of the protective member (13).

7. The thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 6, characterized in that, The positioning block is filled by welding at the welding notch (131). The molten welding wire metal fills the notch and fuses with the positioning block base material. The plug weld metal body (132) formed after cooling and solidification firmly rivets the tungsten sheet to the positioning block.

8. The thread protection device for the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 1, characterized in that, The thickness of the protective component (13) is 0.2-0.4 mm.

9. A method for installing a throttling assembly in a high-temperature gas-cooled reactor steam generator, using the thread protection device for the throttling assembly as described in any one of claims 1-8, comprising the following steps: S1. At the nozzle of each heat exchange tube (6) at the end of the tube sheet (7), install a throttling assembly (2) and an anti-loosening sleeve, wherein the anti-loosening sleeve includes a long anti-loosening sleeve (31) and a short anti-loosening sleeve (32), and weld the long anti-loosening sleeve (31) to the positioning hole plate. S2. For short anti-loosening sleeves (32) that require welding, welding is performed after installing the thread protection device (1) of the throttling component on the corresponding throttling component (2). S3. After removing the thread protection device of the throttling component, install a nut at the end of the throttling component 2.

10. The method for installing the throttling assembly of a high-temperature gas-cooled reactor steam generator according to claim 9, characterized in that, S2 includes the following sub-steps: S21. Align the mounting slot (111) of the throttling component thread protection device (1) with the end of the throttling component (2) and push it upward so that the clamping member (12) clamps the throttling component thread protection device (1) on the throttling component (2) and the protection member (13) is located between the welding area of ​​the short anti-loosening sleeve (32) and the external thread of the throttling component (2). S22. Weld the short anti-loosening sleeve (32) to the side near the protective part (13) so that the short anti-loosening sleeve (32) is welded and fixed to the positioning hole plate, and the first welding is completed. S23. Rotate the thread protection device (1) of the throttling component (90 degrees) and weld the short anti-loosening sleeve (32) close to the protective part (13) to complete the second welding.

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