A manufacturing method of a nuclear island main equipment supporting lug

Abstract

The application discloses a manufacturing method of a nuclear island main equipment supporting bracket, and comprises the following steps: S1, opening a welding groove; S2, temporarily connecting a bottom plate with another bottom plate; S3, preliminarily fixing a first rib plate on the bottom plate by means of manual welding; then, preliminarily fixing another first rib plate on another bottom plate; S4, fixing the first rib plate on the bottom plate and fixing the other first rib plate on the other bottom plate by means of automatic welding; S5, positioning and fixing a second rib plate on the corresponding bottom plate, and temporarily connecting the set first rib plate and the set second rib plate by means of a clamping plate; then, fixing the set second rib plate on the set bottom plate by means of manual welding and automatic welding; and S6, fixing the first rib plate and the second rib plate on the bottom plate. The application can effectively control the welding deformation of the supporting bracket and improve the manufacturing quality of the supporting bracket.

Description

Technical Field

[0001] This invention belongs to the field of structural welding deformation control technology, specifically relating to a method for manufacturing a support lug for the main equipment of a nuclear island. Background Technology

[0002] Support trusses are important supporting components for the main equipment of the nuclear island (such as reactor pressure vessels, steam generators, pressurizers, main pumps, etc.). They directly bear the static load (such as their own weight) and dynamic load of the main equipment of the nuclear island and transfer these loads to the foundation or supporting structure of the plant. This prevents deformation or damage caused by uneven stress on the main equipment of the nuclear island. They are an indispensable part of the high reliability of nuclear power plants, and their reliability is directly related to the operational safety of nuclear power plants.

[0003] Typically, a support truss comprises a base plate, a first stiffening plate, and a second stiffening plate. The support truss is assembled by welding. Because the first and second stiffening plates are ultra-thick forged plates, the welding deformation of the stiffening plates is difficult to control due to the large amount of filler material on one side during welding. After the support truss is assembled, the spacing between the first and second stiffening plates is prone to exceeding tolerances. Furthermore, when the first and second stiffening plates are simultaneously welded to the base plate, the large heat input to the base plate makes welding deformation difficult to control, and the flatness of the base plate is prone to exceeding tolerances after welding. Currently, there is a lack of a manufacturing method for the support truss of the main equipment in the nuclear island to effectively control the welding deformation of the support truss and improve its manufacturing quality. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a method for manufacturing a support truss for the main equipment of a nuclear island, which can effectively control the welding deformation of the support truss and improve the manufacturing quality of the support truss.

[0005] The present invention adopts the following technical solution: A method for manufacturing a support lug for a main nuclear island device, wherein the support lug includes a base plate, a first stiffener plate, and a second stiffener plate; and a fixing assembly for temporarily fixing the support lug includes a connecting plate and a clamping plate. The manufacturing method includes the following steps: S1. For the connection points where the base plate, the first stiffening plate, and the second stiffening plate need to be connected, make welding bevels; S2. Temporarily connect one of the base plates to the other base plate using the connecting plate to ensure that the surfaces of the base plates are in contact with each other; S3. The first stiffening plate is positioned and fixed on the base plate by spot welding. Then, the first stiffening plate is initially fixed on the base plate by manual welding. Then, the assembly unit is flipped over, and another first stiffener plate is positioned and fixed on another base plate by spot welding. Then, the first stiffener plate is initially fixed on the other base plate by manual welding. S4. Using an automatic welding method, one of the first stiffening plates is fixed to one of the base plates, and another of the first stiffening plates is fixed to another of the base plates; S5. The second stiffening plate is positioned and fixed on the corresponding base plate by spot welding, and the first stiffening plate and the second stiffening plate are temporarily connected together by the clamping plate to ensure that the distance between the first stiffening plate and the second stiffening plate meets the design requirements. The second stiffening plate is initially fixed to the base plate by manual welding. Then, the second stiffening plate is fixed to the base plate by automatic welding. S6. Complete the fixing of the first stiffening plate and the second stiffening plate to the base plate.

[0006] Furthermore, in step S1, the first stiffening plate has a first double-sided bevel for welding to the bottom plate; the first stiffening plate has a first single-sided bevel for welding to the reactor pressure vessel cylinder. The second stiffening plate has a second single-sided bevel for welding to the bottom plate; the second stiffening plate has a third single-sided bevel for welding to the reactor pressure vessel shell. The base plate has a fourth single-sided bevel for welding connection with the reactor pressure vessel cylinder.

[0007] Furthermore, the first double-sided bevel adopts a V-shaped bevel with blunt edges and double-sided variable angles; The first single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The second single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The third single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The fourth single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle.

[0008] Further, in step S3, the initial welding and fixing of the first stiffening plate and the base plate includes the following steps: A1. The first stiffening plate is positioned and fixed on the base plate by spot welding at one side bevel of the first stiffening plate. A2. On the other side of the bevel of the first stiffening plate, the first stiffening plate is initially welded and fixed to the base plate by manual welding. A3. Clean the root from the bevel on one side of the first stiffening plate, and then, using manual welding, initially weld and fix the first stiffening plate to the base plate at the bevel on one side. A4. The first stiffening plate is initially welded and fixed onto the base plate.

[0009] Furthermore, in step S3, after the first stiffening plate is spot-welded and fixed onto the base plate, the following steps are also included: B1. Mark several corresponding points on the first stiffening plate near the bevel and on the base plate; at the same time, it is necessary to ensure that the distance between the points on the first stiffening plate is equal or that the distance between the points on the base plate is equal. B2. Next, welding is performed at the bevel of the first stiffening plate. During the welding process, the distance between the points is monitored, and the welding process of the first stiffening plate is adjusted by the change in the distance between the points.

[0010] Furthermore, in step B2, welding is performed simultaneously at one bevel position of the first stiffener plate and another bevel position of the first stiffener plate.

[0011] Furthermore, the spacing between the first stiffener and the second stiffener is controlled at 458mm ± 0.8mm.

[0012] Furthermore, in step S5, the second single-sided bevel of the second stiffener is arranged facing outwards; After the second stiffening plate is spot-welded and fixed, and after the second stiffening plate is limited and fixed using the clamping plate, several corresponding points are marked on the second stiffening plate near the bevel and on the base plate; at the same time, it is necessary to ensure that the distance between the points on the second stiffening plate is equal or that the distance between the points on the base plate is equal. Then, the second stiffener was welded and fixed to the base plate by first manual welding and then automatic welding. Then, before removing the connecting plate and the clamping plate, the support ear bracket is heat-treated; After heat treatment, the inner weld position between the second stiffener and the base plate is cleaned. After cleaning the inner welding position between the second stiffening plate and the base plate, the inner welding position between the second stiffening plate and the base plate is welded by hand. Finally, the second stiffening plate is welded and fixed on the base plate.

[0013] Furthermore, the manual welding is manual argon arc welding; the automatic welding is submerged arc welding.

[0014] Furthermore, the manufacturing method, after step S6, further includes the following steps: S7. Remove the connecting plate used to connect one of the base plates to the other base plate to obtain an independent support ear; S8. Spot weld and fix the support lugs to the reactor pressure vessel cylinder; Then, several corresponding points are marked on the base plate and the reactor pressure vessel cylinder; Then, the first stiffening plate, the second stiffening plate, and the bottom plate were welded and fixed to the reactor pressure vessel cylinder by first manual welding and then automatic welding. Then, before removing the card plate, the support ear bracket is heat-treated; Then, remove the clamping plate connecting the first stiffener and the second stiffener; Next, the inner welding positions between the first stiffening plate and the reactor pressure vessel cylinder are cleaned, the inner welding positions between the second stiffening plate and the reactor pressure vessel cylinder are cleaned, and the inner welding positions between the bottom plate and the reactor pressure vessel cylinder are cleaned. After these inner welding positions are cleaned, they are welded manually. Finally, the first stiffening plate, the second stiffening plate, and the bottom plate are welded and fixed to the reactor pressure vessel cylinder.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: A method for manufacturing a support lug for a nuclear island main equipment includes a connecting plate that temporarily connects one base plate to another. This effectively controls welding deformation caused by welding a first stiffener to the base plate or by welding a second stiffener to the base plate, thus preventing excessive flatness tolerances of the base plate. The method also uses a clamping plate to temporarily connect a designated first stiffener and a designated second stiffener, effectively controlling welding deformation caused by welding either the first or second stiffener to the base plate, and helping to avoid excessive spacing between the first and second stiffeners. In step S3, by first initially welding a first stiffener to one base plate and then initially welding another first stiffener to another base plate, the method utilizes the counter-deformation effect of the subsequent welding of the second first stiffener to control welding deformation caused by welding a first stiffener to the base plate. Similarly, the second stiffener can also be controlled using this method. This invention effectively controls welding deformation of the support lug and improves the manufacturing quality of the support lug. This invention enables the rapid fabrication of two support earpieces through steps S1 to S6, thereby improving the fabrication efficiency of the support earpieces. Attached Figure Description

[0016] The technology of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a top view of the supporting ear bracket; Figure 2 This is the left view of the supporting ear bracket; Figure 3 This is a schematic elevation view of the first and second stiffening plates pre-fixed to the base plate; Figure 4 yes Figure 3 A magnified view of the area at point T (showing the first double-sided bevel); Figure 5 yes Figure 3 A magnified view of the area at point X (representing the second single-sided bevel); Figure 6 This is a diagram of the pallet; Figure 7 This is a schematic elevation view of two support lugs assembled together; Figure 8 This is a left view of the two support lugs assembled together; Figure 9 This is a schematic diagram showing one base plate temporarily connected "back to back" to another during the manufacturing process of the support frame. Figure 9 The left side of the dashed line is a left view of the two base plates placed on the support platform; Figure 9 (The area to the right of the dashed line is a front view of the two base plates placed on the support platform.) Figure 10This is a schematic diagram of the initial connection between the first stiffening plate and the base plate during the fabrication of the support frame. Figure 10 The left side of the dashed line is the left view of the designed assembly unit placed on the support platform; Figure 10 (The area to the right of the dashed line is a front view of the assembled unit placed on the support platform.) Figure 11 This is a schematic diagram of the horizontal automatic welding of the base plate and the first stiffening plate during the manufacturing process of the support bracket. Figure 11 The left side of the dashed line is the left view of the designed assembly unit placed on the support platform; Figure 11 (The area to the right of the dashed line is a front view of the assembled unit placed on the support platform.) Figure 12 This is a schematic diagram of the horizontal connection between the base plate and the second stiffening plate during the manufacturing process of the support frame. Figure 12 The left side of the dashed line is the left view of the designed assembly unit placed on the support platform; Figure 12 (The area to the right of the dashed line is a front view of the assembled unit placed on the support platform.) Figure 13 This is a schematic diagram of the vertical automatic welding of the base plate and the second stiffening plate during the manufacturing process of the support bracket. Figure 13 The left side of the dashed line is the left view of the designed assembly unit placed on the support platform; Figure 13 (The area to the right of the dashed line is a front view of the assembled unit placed on the support platform.) Figure 14 This is a schematic diagram showing the support lugs pre-fixed to the outer wall of the reactor pressure vessel cylinder; Figure 15 This is a top view of the support brackets fixed to the outer wall of the reactor pressure vessel. Figure 16 This is a partial schematic diagram showing the support lugs fixed to the outer wall of the reactor pressure vessel. Figure 17 yes Figure 16 The left view.

[0017] Figure label: 1-Supporting ear bracket; 11-Base plate; A-One of the base plates; B-Another of the base plates; 12-First stiffener; C-One of the first stiffeners; D-Another of the first stiffeners; 13-Second stiffener; Y-One of the second stiffeners; Z-Another of the second stiffeners; E-Spacing; 2-Fixing component; 21-Connecting plate; 22-Clamping plate; 221-Opening; 23-Supporting plate; 31 - First double-sided bevel; F - One-sided bevel; G - The other-sided bevel; 32 - First single-sided bevel; H - Schematic diagram of the outward orientation of the first single-sided bevel; J - Schematic diagram of the inward orientation of the first stiffening plate; 33 - Second single-sided bevel; K - Schematic diagram of the outward orientation of the second single-sided bevel; L - Schematic diagram of the inward orientation of the second stiffening plate; 34 - Third single-sided bevel; M - Schematic diagram of the outward orientation of the third single-sided bevel; 35 - Fourth single-sided bevel; N - Schematic diagram of the outward orientation of the fourth single-sided bevel; P - Schematic diagram of the inward orientation of the base plate; Q - Obtuse edge; R - 50° angle; S - 5° angle; T - First enlarged partial icon number; X - Second enlarged partial icon number; 4-Hanging lugs; 5-Supporting platform; 6-Submerged arc automatic welding equipment; 7-Musketeers; 8-Reactor pressure vessel shell. Detailed Implementation

[0018] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The same reference numerals used throughout the accompanying drawings indicate the same or similar parts.

[0019] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "up," "down," "left," and "right" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.

[0020] Reference Figures 1 to 13 A method for manufacturing a support lug for a main equipment in a nuclear island, wherein the support lug 1 includes a base plate 11, a first stiffener 12, and a second stiffener 13; and a fixing assembly 2 for temporarily fixing the support lug 1 includes a connecting plate 21 and a clamping plate 22. The manufacturing method includes the following steps: S1. For the connection points where the base plate 11, the first stiffening plate 12 and the second stiffening plate 13 need to be connected, make welding bevels; S2. One of the base plates A and another base plate B are temporarily connected together by the connecting plate 21 to ensure that the base plates A and B are in mutual contact. The connecting plate 21 temporarily connects the base plates A and B. When the first stiffener 12 and the second stiffener 13 are welded to the base plate 11, the welding input is large. This design of the present invention can reduce the welding deformation of the base plate 11. S3. The first stiffening plate C is positioned and fixed on the base plate A by spot welding. Then, the first stiffening plate is initially fixed on the base plate A by manual welding. Next, the combined unit (the combined unit, such as a unit composed of "two base plates + connecting plate + one first stiffener") is flipped over, and then the other first stiffener D is positioned and fixed on the other base plate B by spot welding. Then, the first stiffener is initially fixed on the other base plate B by manual welding. Among them, the positions of "one first stiffener C" and "another first stiffener D" are compared with each other and are relatively staggered. This design is also an important technical means for controlling welding deformation in this invention (the "another first stiffener D" is welded later, which has a counter-deformation effect and helps to offset the welding deformation caused by the welding of "one first stiffener C" to the base plate). It also helps to quickly realize the production of two support ear brackets 1 and improves the production efficiency of support ear brackets 1. S4. Using automatic welding, one first stiffening plate C is fixed to one base plate A, and another first stiffening plate D is fixed to another base plate B; S5. The second stiffening plate 13 is positioned and fixed on the corresponding base plate 11 by spot welding, and the first stiffening plate 12 and the second stiffening plate 13 are temporarily connected together by the clamping plate 22 to ensure that the distance between the first stiffening plate 12 and the second stiffening plate 13 meets the design requirements. The second stiffening plate 13 is initially fixed to the base plate 11 by manual welding. Then, the second stiffening plate 13 is fixed to the base plate 11 by automatic welding. Among them, the positions of "one second stiffener Y" and "another second stiffener Z" are compared with each other and are relatively staggered. This design is also an important technical means for controlling welding deformation in this invention ("another second stiffener Z" is welded later and has a reverse deformation effect, which helps to offset the welding deformation caused by welding "one second stiffener Y" to the bottom plate). S6. Complete the fixing of the first stiffening plate 12 and the second stiffening plate 13 onto the base plate 11.

[0021] In one embodiment, in step S1, reference is made to... Figure 3 and Figure 4 The first stiffening plate 12 has a first double-sided bevel 31 for welding to the base plate 11. The first double-sided bevel 31 is designed as such because the first stiffening plate 12 is fixed to the base plate 11 before the second stiffening plate 13, and the welding operation space of the first stiffening plate 12 is not restricted by the second stiffening plate 13. When welding the first stiffening plate 12, manual argon arc welding can be used. First, a root pass is made at the other bevel G, and after a weld thickness of 10mm to 15mm, the root pass is cleaned at one bevel F (i.e., root pass on the reverse side of the weld). Then, manual argon arc welding is used to make a root pass at the same bevel F, and a weld thickness of 19mm to 21mm is made. After the weld heights on both sides of the bevel are the same, submerged arc welding is used to alternately and symmetrically weld the two sides of the bevel, ensuring that the heat input on both sides of the bevel is the same, effectively avoiding deformation of the first stiffening plate 12 due to different heat inputs. (Refer to...) Figure 1 and Figure 16 The first stiffener 12 has a first single-sided bevel 32 for welding connection with the outer wall of the reactor pressure vessel cylinder 8. Reference Figure 3 and Figure 5 The second stiffening plate 13 has a second single-sided bevel 33 for welding connection with the base plate 11; refer to Figure 1 and Figure 16 The second stiffener 13 has a third single-sided bevel 34 for welding connection with the outer wall of the reactor pressure vessel cylinder 8; Reference Figure 1 , Figure 2 , Figure 16 and Figure 17 The base plate 11 has a fourth single-sided bevel 35 for welding connection with the outer wall of the reactor pressure vessel cylinder 8.

[0022] In one embodiment, refer to Figure 3 and Figure 4 The first double-sided bevel 31 adopts a V-shaped bevel with a blunt edge and variable angle on both sides; preferably, the root of the first double-sided bevel 31 has a blunt edge Q of 1mm to 2mm, which is conducive to achieving full penetration welding at the root of the bevel; the first double-sided bevel 31 is symmetrical on both sides (combined with...) Figure 4 The diagram shows "one side bevel F" and "the other side bevel G," indicating "double-sided symmetry of the bevel." Each bevel has a 50° angle and a 5° angle (note: the 50° angle and the 5° angle constitute a variable angle bevel); the 50° angle is referenced... Figure 4As shown by R in the figure; 5° reference angle. Figure 4 As shown by S in the figure; Reference Figure 1 The first single-sided bevel 32 adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; preferably, the root of the first single-sided bevel 32 has a blunt edge of 1mm to 2mm, which is conducive to achieving full penetration welding at the root of the bevel; the first single-sided bevel 32 has a 50° angle and a 5° angle (Note: the 50° angle and the 5° angle constitute a variable angle bevel). Reference Figure 3 and Figure 5 The second single-sided bevel 33 adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; preferably, the root of the second single-sided bevel 33 has a blunt edge Q of 1mm to 2mm, which is conducive to achieving full penetration welding at the root of the bevel; the second single-sided bevel 33 has a 50° angle and a 5° angle (Note: the 50° angle and the 5° angle constitute a variable angle bevel); wherein, the 50° angle refers to... Figure 5 As shown by R in the figure; 5° reference angle. Figure 5 As shown by S in the figure; Reference Figure 1 The third single-sided bevel 34 adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; preferably, the root of the third single-sided bevel 34 has a blunt edge of 1mm to 2mm, which is conducive to achieving full penetration welding at the root of the bevel; the third single-sided bevel 34 has a 50° angle and a 5° angle (Note: the 50° angle and the 5° angle constitute a variable angle bevel). Reference Figure 17 The fourth single-sided bevel 35 adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; preferably, the root of the fourth single-sided bevel 35 has a blunt edge of 1mm to 2mm, which is conducive to achieving full penetration welding at the root of the bevel; the fourth single-sided bevel 35 has a 50° angle and a 5° angle (Note: the 50° angle and the 5° angle constitute a variable angle bevel).

[0023] Combination Figure 3 , Figure 4 , Figure 9 and Figure 10 To understand this, in one embodiment, step S3 involves the preliminary welding and fixing of the first stiffening plate 12 to the base plate 11, which includes the following steps: A1. The first stiffening plate 12 is positioned and fixed on the base plate 11 by spot welding at the bevel F on one side of the first stiffening plate 12. A2. On the other side of the bevel G of the first stiffening plate 12, the first stiffening plate 12 is initially welded and fixed to the base plate 11 by manual welding. A3. Clean the root from the bevel F on one side of the first stiffening plate 12, and then, by manual welding, fix the first stiffening plate 12 to the base plate 11. A4. The first stiffening plate 12 is initially welded and fixed onto the base plate 11.

[0024] When initially welding "one of the first stiffening plates C" onto "one of the base plates A", steps A1 to A4 can be used; similarly, when initially welding "another of the first stiffening plates D" onto "another of the base plates B", steps A1 to A4 can be used.

[0025] In one embodiment, after spot welding and fixing the first stiffening plate 12 onto the base plate 11 in step S3, the following steps are also included: B1. Mark several corresponding points on the first stiffening plate 12 near the bevel and on the base plate 11; at the same time, it is necessary to ensure that the distance between the points on the first stiffening plate 12 is equal or that the distance between the points on the base plate 11 is equal. B2. Then, welding is performed at the bevel of the first stiffening plate 12. During the welding process, the distance between the points is monitored, and the welding process of the first stiffening plate 12 is adjusted by the change in the distance between the points.

[0026] Specifically, after the first stiffening plate 12 and the base plate 11 are spot-welded and fixed, four points are marked on the first stiffening plate 12 near the bevel and on the base plate 11. At the same time, it is necessary to ensure that the distance between the four points on the first stiffening plate 12 is equal or that the distance between the four points on the base plate 11 is equal. This design is conducive to monitoring the welding deformation of the first stiffening plate 12 during the welding process. When the distance between the four points on the first stiffening plate 12 is not equal, the side with the larger distance between the two points should be welded to achieve welding deformation control.

[0027] Reference Figures 9 to 13 In one embodiment, the connecting plate 21 is provided with a lifting lug 4. When the set assembly unit needs to be turned over, the lifting lug 4 is used to help the set assembly unit turn over. Here, the "set assembly unit" refers to the unit formed by timely combination of corresponding components during the assembly process of the support frame 1 (assembly unit: such as a unit composed of "two base plates + connecting plate + first stiffening plate"; assembly unit: such as a unit composed of "two base plates + connecting plate + two first stiffening plates + second stiffening plate").

[0028] Reference Figures 9 to 13In one embodiment, the set assembly unit is placed on a set support platform 5; the support platform 5 (such as a stand) is used to support the assembly unit.

[0029] Reference Figure 11 In one embodiment, in step B2, welding (submerged arc welding) is performed simultaneously at the bevel position of one first stiffener C and the bevel position of another first stiffener D.

[0030] Combination Figure 3 and Figure 11 In one embodiment, the combined unit consisting of "two base plates 11 + connecting plate 21 + lifting lug 4 + two first stiffening plates 12" is placed on the support platform 5. The fixing component 2 for temporarily fixing the support lug 1 also includes a support plate 23. The lower end of the support plate 23 is connected to the support platform 5, and the upper end is connected to the first stiffening plate 12. This allows the first stiffening plate 12 to be placed "horizontally" on the support platform 5, which is beneficial for the submerged arc welding equipment 6 to perform submerged arc welding on the first stiffening plate 12. This also helps to avoid excessive welding deformation of the first stiffening plate 12 during the welding process. Furthermore, the "horizontal" placement of the first stiffening plate 12 on the support platform 5 facilitates the simultaneous submerged arc welding of "one first stiffening plate C" and "another first stiffening plate D", improving manufacturing efficiency. Preferably, after the first stiffening plate 12 is welded and fixed on the base plate 11, the first stiffening plate 12 and the base plate 11 can be heat-treated using a torch 7.

[0031] Combination Figure 3 To understand this, in one embodiment, the distance E between the first stiffener 12 and the second stiffener 13 is controlled at 458mm ± 0.8mm. In one embodiment, taking one of the support lugs 1 as the research object, it is required that after the first stiffener 12 and the second stiffener 13 are welded to the base plate 11, the distance E between the first stiffener 12 and the second stiffener 13 is 458mm ± 0.8mm (where 0.8mm is the error), and the flatness error of the base plate 11 is required to be 0.1mm.

[0032] Combination Figure 3 , Figure 5 and Figure 7 To understand this, in one embodiment, in step S5, the second single-sided bevel 33 of the second stiffening plate 13 is arranged outward (wherein, in conjunction with...) Figure 3 (Understanding K in the context) After the second stiffening plate 13 is spot-welded and fixed, and after the second stiffening plate 13 is limited and fixed using the clamping plate 22, several corresponding points are marked on the second stiffening plate 13 near the bevel and on the base plate 11. At the same time, it is necessary to ensure that the distance between the points on the second stiffening plate 13 is equal or that the distance between the points on the base plate 11 is equal. Specifically, after the second stiffening plate 13 is spot-welded and fixed to the base plate 11, at least three clamping plates 22 are used to temporarily connect the first stiffening plate 12 and the second stiffening plate 13 together. The clamping plate 22 is beneficial to control the distance E between the first stiffening plate 12 and the second stiffening plate 13 to 458mm ± 0.8mm. Then, the second stiffener 13 is welded and fixed to the base plate 11 by manual welding and then by automatic welding. Specifically, the root pass is first made by manual argon arc welding at the second single-sided bevel 33, and after the weld thickness is 10mm to 15mm, the weld is completed by submerged arc automatic welding. The second single-sided bevel 33 is a single-sided bevel facing outwards. After welding, the second single-sided bevel 33 has a counter-deformation effect (caused by welding), which helps to offset the welding deformation caused by the welding of the first stiffener 12 onto the base plate 11. This design is also an important means for improving the manufacturing quality of the support lug 1. Furthermore, the outward orientation of the second single-sided bevel 33 provides sufficient operating space for the welding equipment. The outward orientation of the second single-sided bevel 33 also lays the groundwork for cleaning the inner welding position (in conjunction with...). Figure 7 (The L in the text refers to the inner welding position). Subsequently, before removing the connecting plate 21 and the clamping plate 22, the support ear bracket 1 is subjected to heat treatment (see reference). Figure 13 For example, the flame generated by the torch 7 is used to heat the support lug 1 to eliminate the welding residual stress between the first stiffener 12 and the base plate 11, and to eliminate the welding residual stress between the second stiffener 13 and the base plate 11; preferably, this heat treatment is also beneficial to improving the microstructure and properties of the welded joint, improving the plasticity of the weld metal, reducing the hardness of the heat-affected zone, and improving the fracture toughness and fatigue strength. After heat treatment, the inner weld position between the second stiffening plate 13 and the base plate 11 is cleaned (combined with...). Figure 7 (The L in the text refers to the inner welding position); root cleaning usually refers to removing welds with welding defects at the root. After cleaning the inner welding position between the second stiffening plate 13 and the base plate 11, the inner welding position between the second stiffening plate 13 and the base plate 11 is welded by hand. Finally, the second stiffening plate 13 is welded and fixed to the base plate 11.

[0033] Combination Figure 3 and Figure 7 To understand this, in one embodiment, specifically, the two support lugs 1 have a total of two second stiffeners 13 (e.g., "one second stiffener Y" and "another second stiffener Z"). The "one second stiffener Y" can be welded first, and then the "combined unit" can be flipped over before welding the "another second stiffener Z". Unlike the two "first stiffeners 12", the two "second stiffeners 13" cannot be welded simultaneously (submerged arc welding). The two "second stiffeners 13" are welded in a sequential order (both are overhead welding operations). During the process, the "combined unit" is flipped over as needed to avoid overhead welding of one of the second stiffeners 13, thereby improving the weld quality.

[0034] Combination Figure 3 , Figure 6 and Figure 7 In one embodiment, the card plate 22 is a "mountain" shaped card plate, and the opening of the "mountain" shaped card plate is used for limiting connection with the corresponding rib plate. Specifically, one opening 221 of the "mountain" shaped card plate is limited and connected to the first rib plate 12, and the other opening 221 of the "mountain" shaped card plate is limited and connected to the second rib plate 13. Preferably, after the "mountain" shaped card plate is limited and connected to the first rib plate 12 and the second rib plate 13 respectively, the "mountain" shaped card plate is also spot welded to the first rib plate 12 and the second rib plate 13 for fixation. When removing the "mountain" shaped card plate later, the weld points can be cut off.

[0035] Combination Figure 7 , Figure 14 , Figure 15 , Figure 16 and Figure 17 To understand this, in one embodiment, the manufacturing method, after step S6, further includes the following step: S7. Remove the connecting plate 21 used to connect one of the base plates A and the other base plate B to obtain the independent support lug 1; wherein, since the support lug 1 still needs to be welded to the outer wall of the reactor pressure vessel cylinder 8, a "mountain" shaped clamping plate is still needed to control welding deformation, so the "mountain" shaped clamping plate between the first stiffener 12 and the second stiffener 13 (Note: used as an anti-deformation tooling) is not removed for the time being; S8. Spot weld and fix the support lug 1 to the outer wall of the reactor pressure vessel cylinder 8; Subsequently, several corresponding points are marked on the base plate 11 and the outer wall of the reactor pressure vessel cylinder 8. For example, two points are marked on the base plate 11 and the outer wall of the reactor pressure vessel cylinder 8 respectively. When the first stiffener 12 and the second stiffener 13 are welded to the outer wall of the reactor pressure vessel cylinder 8, these points can facilitate people to monitor the deformation of the base plate 11. Subsequently, the first stiffening plate 12, the second stiffening plate 13, and the base plate 11 were welded and fixed to the reactor pressure vessel cylinder 8 using both manual and automatic welding methods; wherein, the first single-sided bevel 32 is also arranged facing outwards (in conjunction with...). Figure 1 and Figure 16 (Understanding H in the text), the third single-sided bevel 34 is also arranged relatively outwards (in conjunction with...) Figure 1 and Figure 16 (Understanding M in the text), the fourth single-sided bevel 35 is also arranged relatively outwards (in conjunction with...) Figure 17 (Understanding N in the original text); specifically, firstly, "using manual argon arc welding, a root pass is made at the first single-sided bevel 32, with a weld thickness of 10mm to 15mm, to initially connect the first stiffening plate 12 to the outer wall of the reactor pressure vessel cylinder 8"; secondly, "using manual argon arc welding, a root pass is made at the third single-sided bevel 34, with a weld thickness of 10mm to 15mm, to initially connect the second stiffening plate 13 to the outer wall of the reactor pressure vessel cylinder 8"; then, "using manual argon arc welding, a root pass is made at the fourth single-sided bevel 35, with a weld thickness of 20mm to 25mm, to initially connect the base plate 11 to the outer wall of the reactor pressure vessel cylinder 8". After "connecting", the first stiffening plate 12 is then "welded to the outer wall of the reactor pressure vessel cylinder 8 using submerged arc automatic welding", the second stiffening plate 13 is then "welded to the outer wall of the reactor pressure vessel cylinder 8 using submerged arc automatic welding", and the bottom plate 11 is then "welded to the outer wall of the reactor pressure vessel cylinder 8 using submerged arc automatic welding". This welding process is an important technical means for controlling welding deformation in this invention. It can prevent the weld between the bottom plate 11 and the outer wall of the reactor pressure vessel cylinder 8 from cracking due to the large welding heat input when automatically welding the first stiffening plate 12, the second stiffening plate 13 and the outer wall of the reactor pressure vessel cylinder 8. Subsequently, before removing the clamping plate 22, the supporting lug 1 is heat-treated to eliminate residual welding stress between the first stiffening plate 12 and the reactor pressure vessel cylinder 8, to eliminate residual welding stress between the second stiffening plate 13 and the reactor pressure vessel cylinder 8, and to eliminate residual welding stress between the bottom plate 11 and the reactor pressure vessel cylinder 8. Preferably, this heat treatment also helps to improve the microstructure and properties of the weld joint, improve the plasticity of the weld metal, reduce the hardness of the heat-affected zone, and improve the fracture toughness and fatigue strength. Then, the clamping plate 22 connecting the first stiffening plate 12 and the second stiffening plate 13 is removed; Subsequently, the inner weld positions between the first stiffening plate 12 and the reactor pressure vessel cylinder 8 are cleaned, the inner weld positions between the second stiffening plate 13 and the reactor pressure vessel cylinder 8 are cleaned, and the inner weld positions between the bottom plate 11 and the reactor pressure vessel cylinder 8 are cleaned (in conjunction with...). Figure 17 (Understanding P in the text) Clean the root; after cleaning the root of these inner welding positions, perform welding on these inner welding positions by manual welding. Finally, the first stiffening plate 12, the second stiffening plate 13, and the bottom plate 11 are welded and fixed to the reactor pressure vessel cylinder 8.

[0036] In one embodiment, the manual welding is manual argon arc welding; the automatic welding is submerged arc welding (performed by submerged arc welding equipment 6). The welding of the first stiffener 12 to the base plate 11, the welding of the second stiffener 13 to the base plate 11, the welding of the first stiffener 12 to the reactor pressure vessel cylinder 8, the welding of the second stiffener 13 to the reactor pressure vessel cylinder 8, and the welding of the base plate 11 to the reactor pressure vessel cylinder 8 can be performed by first using manual argon arc welding (for the root pass) and then using submerged arc welding (note: the main welding mode). The submerged arc welding of this invention is beneficial for improving welding efficiency. If the weld between the first stiffening plate 12 and the base plate 11 is defined as the first weld, the weld between the second stiffening plate 13 and the base plate 11 is defined as the second weld, the weld between the first stiffening plate 12 and the reactor pressure vessel cylinder 8 is defined as the third weld, the weld between the second stiffening plate 13 and the reactor pressure vessel cylinder 8 is defined as the fourth weld, and the weld between the base plate 11 and the reactor pressure vessel cylinder 8 is defined as the fifth weld, then 80% of the five welds in this invention can be welded using submerged arc welding, which greatly improves the welding efficiency (Note: Submerged arc welding efficiency is higher than manual argon arc welding efficiency), and the use of submerged arc welding can improve the welding quality of the weld.

[0037] In one embodiment, after the support lug 1 is welded and fixed to the reactor pressure vessel cylinder 8, taking one support lug 1 as the research object, the distance between the first stiffener 12 and the second stiffener 13 is required to be 458mm ± 0.8mm (where 0.8mm is the error), and the flatness error of the base plate 11 is required to be 0.1mm.

[0038] In one embodiment, the maximum thickness of the base plate 11 is 274 mm; the thickness of the first stiffening plate 12 and the second stiffening plate 13 is 134 mm (belonging to ultra-thick forged plates); the wall thickness of the reactor pressure vessel cylinder 8 is 240 mm; the base plate 11, the first stiffening plate 12, and the second stiffening plate 13 are all "SA-508-3 steel", where "SA" indicates that this is part of the ASME standard, specifically the material standard in the ASME Boiler and Pressure Vessel Code (BPVC); "508" indicates the specific material standard number, namely the ASME SA-508 standard; and "3" indicates the specific grade of the steel.

[0039] This invention discloses a method for manufacturing a support lug for the main equipment of a nuclear island. Steps S1 to S6 improve the welding efficiency and quality of the support lug; steps S7 to S8 improve the welding quality of fixing the support lug to the reactor pressure vessel cylinder. The invention effectively solves the problem of difficult-to-control welding deformation during the welding of the support lug. This method effectively improves the production quality of the product (support lug + reactor pressure vessel cylinder) and increases the manufacturing efficiency of the product.

[0040] Other aspects of the manufacturing method of the main equipment support bracket for the nuclear island described in this invention can be found in the prior art and will not be repeated here.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for manufacturing a support bracket for the main equipment of a nuclear island, characterized in that, The support bracket includes a base plate, a first stiffening plate, and a second stiffening plate; the fixing components for temporarily fixing the support bracket include a connecting plate and a clamping plate; The manufacturing method includes the following steps: S1. Welding bevels are made for the base plate, the first stiffening plate and the second stiffening plate; In step S1, the first stiffening plate has a first double-sided bevel for welding to the bottom plate; the first stiffening plate has a first single-sided bevel for welding to the reactor pressure vessel shell. The second stiffening plate has a second single-sided bevel for welding to the bottom plate; the second stiffening plate has a third single-sided bevel for welding to the reactor pressure vessel shell. The base plate is provided with a fourth single-sided bevel for welding connection with the reactor pressure vessel cylinder. S2. Temporarily connect one of the base plates to the other base plate using the connecting plate to ensure that the surfaces of the base plates are in contact with each other; S3. The first stiffening plate is positioned and fixed on the base plate by spot welding. Then, the first stiffening plate is initially fixed on the base plate by manual welding. Then, the assembly unit is flipped over, and another first stiffener plate is positioned and fixed on another base plate by spot welding. Then, the first stiffener plate is initially fixed on the other base plate by manual welding. S4. Using an automatic welding method, one of the first stiffening plates is fixed to one of the base plates, and another of the first stiffening plates is fixed to another of the base plates; S5. The second stiffening plate is positioned and fixed on the corresponding base plate by spot welding, and the first stiffening plate and the second stiffening plate are temporarily connected together by the clamping plate to ensure that the distance between the first stiffening plate and the second stiffening plate meets the design requirements. The second stiffening plate is initially fixed to the base plate by manual welding. Then, the second stiffening plate is fixed to the base plate by automatic welding. S6. Complete the fixing of the first stiffening plate and the second stiffening plate to the base plate.

2. The method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 1, characterized in that, The first double-sided bevel adopts a V-shaped bevel with blunt edges and variable angles on both sides; The first single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The second single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The third single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle; The fourth single-sided bevel adopts a V-shaped bevel with a blunt edge and a single-sided variable angle.

3. The method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 1, characterized in that, In step S3, the initial welding and fixing of the first stiffening plate and the base plate includes the following steps: A1. The first stiffening plate is positioned and fixed on the base plate by spot welding at one side bevel of the first stiffening plate. A2. On the other side of the bevel of the first stiffening plate, the first stiffening plate is initially welded and fixed to the base plate by manual welding. A3. Clean the root from the bevel on one side of the first stiffening plate, and then, using manual welding, initially weld and fix the first stiffening plate to the base plate at the bevel on one side. A4. The first stiffening plate is initially welded and fixed onto the base plate.

4. A method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 3, characterized in that, In step S3, after the first stiffening plate is spot-welded and fixed onto the base plate, the following steps are also included: B1. Mark several corresponding points on the first stiffening plate near the bevel and on the base plate; at the same time, it is necessary to ensure that the distance between the points on the first stiffening plate is equal or that the distance between the points on the base plate is equal. B2. Next, welding is performed at the bevel of the first stiffening plate. During the welding process, the distance between the points is monitored, and the welding process of the first stiffening plate is adjusted by the change in the distance between the points.

5. A method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 4, characterized in that, In step B2, welding is performed simultaneously at one bevel position of the first stiffener plate and another bevel position of the first stiffener plate.

6. A method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 1, characterized in that, The spacing between the first stiffener and the second stiffener is controlled at 458mm ± 0.8mm.

7. A method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 1, characterized in that, In step S5, the second single-sided bevel of the second stiffener is arranged facing outwards; After the second stiffening plate is spot-welded and fixed, and after the second stiffening plate is limited and fixed using the clamping plate, several corresponding points are marked on the second stiffening plate near the bevel and on the base plate; at the same time, it is necessary to ensure that the distance between the points on the second stiffening plate is equal or that the distance between the points on the base plate is equal. Then, the second stiffener was welded and fixed to the base plate by first manual welding and then automatic welding. Then, before removing the connecting plate and the clamping plate, the support ear bracket is heat-treated; After heat treatment, the inner weld position between the second stiffener and the base plate is cleaned. After cleaning the inner welding position between the second stiffening plate and the base plate, the inner welding position between the second stiffening plate and the base plate is welded by hand. Finally, the second stiffening plate is welded and fixed on the base plate.

8. A method for manufacturing a support bracket for the main equipment of a nuclear island according to claim 1, characterized in that, The manual welding is manual argon arc welding; the automatic welding is submerged arc welding.

9. A method for manufacturing a support bracket for the main equipment of a nuclear island according to any one of claims 1 to 8, characterized in that, Following step S6, the following steps are also included: S7. Remove the connecting plate used to connect one of the base plates to the other base plate to obtain an independent support ear; S8. Spot weld and fix the support lugs to the reactor pressure vessel cylinder; Then, several corresponding points are marked on the base plate and the reactor pressure vessel cylinder; Then, the first stiffening plate, the second stiffening plate, and the bottom plate were welded and fixed to the reactor pressure vessel cylinder by first manual welding and then automatic welding. Then, before removing the card plate, the support ear bracket is heat-treated; Then, remove the clamping plate connecting the first stiffener and the second stiffener; Next, the inner welding positions between the first stiffening plate and the reactor pressure vessel cylinder are cleaned, the inner welding positions between the second stiffening plate and the reactor pressure vessel cylinder are cleaned, and the inner welding positions between the bottom plate and the reactor pressure vessel cylinder are cleaned. After these inner welding positions are cleaned, they are welded manually. Finally, the first stiffening plate, the second stiffening plate, and the bottom plate are welded and fixed to the reactor pressure vessel cylinder.

Images