Neutron shielding block mounting structure and mounting method in fusion reactor vacuum chamber sector joint area

Abstract

The application provides a kind of installation structure and installation method of neutron shielding block in fusion reactor vacuum chamber sector joint area, belongs to nuclear fusion reactor installation technical field, the two sides of vacuum chamber edge rib plate are connected with vacuum chamber inner shell and outer shell respectively, and the gap between the butt joint side of adjacent two vacuum chamber outer shells is fixed with outer shell splice plate;Positioning block is fixed on the surface of outer shell splice plate towards the gap side of two vacuum chamber inner shells, the end of positioning block away from outer shell splice plate is fixed with shielding block assembly, shielding block includes inner and outer two layers of shielding block, and bushing washer is arranged between the two shielding blocks;After fastening screw is axially passed through two layers of shielding block and bushing washer, it is screwed into the end face of positioning block in threaded cooperation;The two sides of inner layer shielding block are integrally provided with wing fins fixed with two vacuum chamber edge rib plates respectively.The application can meet simple and quick assembly under narrow space, and still can complete the installation of joint area neutron shielding block under large assembly error of vacuum chamber sector.

Description

Technical Field

[0001] This invention belongs to the field of fusion reactor installation technology, and more specifically, it relates to an installation structure and method for a neutron shielding block in the joint area of ​​a fusion reactor vacuum chamber sector. Background Technology

[0002] The vacuum chamber is a core component of a tokamak fusion device. It provides a high-quality vacuum environment for plasma operation, supports internal components, and bears loads during both normal and abnormal plasma operation. During device operation, the vacuum chamber is exposed to a large amount of neutron radiation; therefore, a neutron shielding structure needs to be designed within it. Currently, there is considerable research on in-wall shielding (IWS) for fusion reactor devices, but research on field joint shielding is scarce. How to simply and reliably install field joint shielding within the confined space of the field joint is a crucial step in the loop-closing of the nuclear fusion device.

[0003] Currently, some fusion reactors use interlocking plates welded together at the seams between vacuum chamber sectors. Neutron shielding blocks are installed between these inner and outer shell interlocking plates. Some fusion reactors employ a modular design for the neutron shielding blocks in the seam area. This structure divides the neutron shielding block into three equal-width parts. Each part consists of at least three layers of shielding blocks pre-assembled using bolts and washers. A groove is then cut into the outermost shielding block, and the three parts are fixed together as a single unit using external brackets and screws, which is then installed in the seam area between the vacuum chamber sectors. This modular structure, with its small size, can accommodate installation in the confined space of the vacuum chamber seam area. However, it places extremely stringent requirements on the custom manufacturing of the shielding blocks and external brackets, and also imposes strict requirements on the tolerances between the shielding blocks, making manufacturing and installation very difficult.

[0004] After the outer shell splicing plates are welded together, the shielding blocks in the fusion reactor seam area are installed between the outer shell splicing plates in the vacuum chamber sector. Some fusion reactors use threaded holes in the vacuum chamber stiffeners on both sides of the seam area to install mounting brackets. The shielding block assembly is then installed onto the stiffeners on both sides of the vacuum chamber using brackets and screws. This method can fix the shielding blocks in the seam area. However, when assembling the two sectors of the fusion reactor vacuum chamber, the tolerances introduced during manufacturing and on-site assembly will inevitably lead to assembly errors between the two sectors. Furthermore, the shrinkage deformation caused by welding the inner and outer shell splicing plates to the vacuum chamber shell during the seam area can cause misalignment at the edges of the vacuum chamber sector. Once the stiffeners on both sides are misaligned, the mounting holes of the brackets will shift, leading to bracket breakage and loosening or breakage of the mounting bolts inside the shielding block assembly. In addition, each shielding block consists of at least three layers, is heavy, cannot be installed manually, and relies entirely on mechanical connections using brackets and bolts. This places high demands on the functionality of the installation tools, resulting in long tool development cycles and high costs.

[0005] Therefore, it is evident that some fusion reactor vacuum chamber sectors are joined using splicing plates. These plates, along with the stiffening ribs on both sides of the vacuum chamber sectors, form joint areas. The neutron shielding blocks in these joint areas are installed inside the vacuum chamber after the outer shell is welded but before the inner shell. Some fusion reactor vacuum chambers can reach heights of over ten meters and weigh nearly a hundred tons. During manufacturing, errors in the edge contours of the vacuum chamber sector segments are inevitable, leading to misalignment at the sector joint areas during assembly. Furthermore, in some fusion reactors with a shell thickness of 40mm (such as ITER), welding shrinkage during the welding of the inner and outer shell splicing plates can also cause deformation of the stiffening ribs on both sides of the vacuum chamber sectors.

[0006] Furthermore, due to assembly logic and space limitations, some compact fusion reactors can only be welded on one side inside the vacuum chamber. Therefore, the neutron shielding block in the joint area needs to be installed between the two inner stiffening plates of the vacuum chamber through the gap in the inner shell. The extremely limited installation space in some compact fusion reactors greatly restricts the structural design of the neutron shielding block in the joint area.

[0007] Because there are no supports or mounting points inside the seam area of ​​the fusion reactor vacuum chamber, the neutron shielding blocks in the seam area are mounted on the stiffening plates or splicing plates on both sides of the vacuum chamber with a designed support structure. Some fusion reactors, such as ITER, pre-machine threaded holes on the stiffening plates on both sides during vacuum chamber manufacturing. During installation, these threaded holes and a custom-made support frame are used to fix the neutron shielding blocks in the seam area. However, the installation and welding of the vacuum chamber sectors can cause misalignment of the stiffening plates on both sides of the seam area, leading to displacement of the support mounting holes. This can result in risks such as the shielding blocks being unable to be installed, the mounting bracket breaking, or the internal mounting bolts of the shielding block assembly becoming loose or broken.

[0008] Among the existing technical solutions currently known, only Wang Yan's "Design and Virtual Assembly of FJ Neutron Shielding Layer" demonstrates the structural design and installation method of the neutron shielding block in the seam area of ​​ITER. However, its component structure is complex, the installation steps are numerous and the tolerance requirements are strict. Furthermore, the structure and installation method in this solution do not take into account the errors caused by assembly and welding. Therefore, there is currently a lack of structural design and installation methods for neutron shielding blocks in the seam area in China. Summary of the Invention

[0009] In view of the current state of the technology mentioned in the background, and in order to overcome the corresponding defects in the prior art, the present invention specifically discloses an installation structure and method for neutron shielding blocks in the joint area of ​​a fusion reactor vacuum chamber sector. This method can meet the assembly requirements in the extremely narrow space of the vacuum chamber joint area, and is simple and easy to process. It enables the installation of neutron shielding blocks in the joint area to be completed even when the shielding blocks have large assembly errors in the vacuum chamber sector.

[0010] To overcome the deficiencies of the existing technology, those skilled in the art provide the following technical solutions:

[0011] A neutron shielding block installation structure for the joint area of ​​a fusion reactor vacuum chamber sector includes two vacuum chamber edge stiffeners located between the inner and outer shells of the vacuum chamber, with each side of the edge stiffeners connected to the inner and outer shells respectively. An outer shell splicing plate is fixed in the gap between the mating sides of two adjacent outer shells to connect the two vacuum chamber shells. A positioning block is fixed on the surface of the outer shell splicing plate facing the gap between the two inner shells, and a shielding block assembly is fixed to the end of the positioning block away from the outer shell splicing plate. The shielding block includes an outer shielding block and an inner shielding block that face each other and are parallel to each other, with a bushing washer between the two shielding blocks to separate them. A fastening screw is also included, which axially passes through the two shielding blocks and the bushing washer, and then threaded into the end face of the positioning block. Wings are integrally formed on both sides of the inner shielding block for fixed connection with the two vacuum chamber edge stiffeners.

[0012] Furthermore, the bushing gasket includes a cylindrical body and an annular portion coaxially fixed to the outside of the body.

[0013] Furthermore, the main body and the annular portion are integrally formed, and the main body, excluding both ends of the annular portion, is vertically inserted into the outer shielding block and the inner shielding block, respectively. The end of the positioning block with a threaded hole is inserted into the outer shielding block. The inner shielding block includes a second shielding block and a first shielding block. Both the second and first shielding blocks have an L-shaped recessed platform structure on one side. The stepped surfaces of the two recessed platforms fit together to achieve the assembly and splicing of the second and first shielding blocks, and the fastening screws pass vertically through the recessed platform structures. The second and first shielding blocks each have wings on the side facing away from the recessed platform structure.

[0014] Meanwhile, this invention also proposes an installation method for a neutron shielding block installation structure in the joint area of ​​a fusion reactor vacuum chamber sector, which mainly involves the following steps:

[0015] S1. First, install the outer shell splicing plate: Set the two vacuum chamber sectors on both sides of the joint area of ​​the vacuum chamber sector to be staggered, and set the stagger to 20mm. Place the outer shell splicing plate between the two vacuum chamber sectors, and then weld and fix it to the side of the corresponding vacuum chamber outer shell respectively.

[0016] S2. Customize the positioning block according to the measurement data. The positioning block has threaded holes for installing the fastening screws and a welding bevel is machined. Weld one end of the positioning block to the outer shell splicing plate through the gap between the inner and outer shells of the vacuum chamber.

[0017] S3. Place the outer shielding block at an angle into the joint area, and after aligning it inside the joint area, install it onto the positioning block. Leave gaps between the outer shielding block and the splicing plate and the vacuum chamber edge stiffeners on both sides.

[0018] S4. Install one end of the bushing washer onto the outer shielding block;

[0019] S5. Place the inner shielding block on the bushing washer and spot weld its wings on both sides to the edge stiffener of the vacuum chamber.

[0020] S6. Use screws to fix the inner shielding block to the positioning block, thereby realizing the installation and fixing of the inner and outer shielding blocks and completing the installation of a row of shielding blocks.

[0021] S7. Weld the two edges on one side of the wing to the edge stiffeners of the two vacuum chambers to complete the reinforcement and fixation.

[0022] Preferably, the spacing between the edge stiffeners of the two vacuum chambers is 260mm, the spacing between the outer shell of the vacuum chamber and the inner shell of the vacuum chamber is 110mm, and the width of the joint area between the two inner shells of the vacuum chamber is 180mm.

[0023] Preferably, when a welding bevel is made on the positioning block, the bevel angle is not less than 45° and the bevel depth is 8~10mm; the thickness of the bushing gasket is 5mm, and the length of the bushing at both ends outside the gasket is not less than 5mm.

[0024] Preferredly, when setting the two vacuum chamber sectors on both sides of the joint area of ​​the vacuum chamber sector with staggered edges, a staggered clamping mechanism is used. The staggered clamping mechanism includes: a first clamping arm assembly and a second clamping arm assembly for clamping the outer shells of two adjacent vacuum chambers respectively. The second clamping arm assembly is axially slidably installed inside the first clamping arm assembly, and a core column perpendicular to it is fixed on the first clamping arm. A ring sleeve is coaxially rotatably installed on the core column. A threaded sleeve is radially fixed on the cylindrical surface of the ring sleeve. A lead screw is coaxially threaded into the free end of the threaded sleeve. The lead screw has a length direction with Scale dimension lines; In use, first use the two clamping arm assemblies to clamp the two adjacent vacuum chamber shells, and fix the first clamping arm assembly in place. Screw the lead screw out of the threaded sleeve until the top end contacts the concave side of the first vacuum chamber shell near the joint area. Then continue to rotate the threaded sleeve, and after the end of the lead screw leaves the first vacuum chamber shell, continue to screw the lead screw outward by a length of t. Then continue to rotate the threaded sleeve and slide it to the concave side of the second vacuum chamber shell, pushing the second vacuum chamber shell and the second clamping arm assembly to slide into place together. At this time, fix the two clamping arm assemblies.

[0025] Preferably, both clamping arm assemblies include a hydraulic cylinder, a piston rod, an outer pressure block, an inner pressure block, and a mounting base. The hydraulic cylinder is mounted on one end of the mounting base. The piston rod extends and retracts axially under the drive of the hydraulic cylinder. The piston rod is L-shaped, and the inner pressure block is fixed to the end of the piston rod. The outer pressure block is fixedly mounted on the bottom of the hydraulic cylinder. When the piston rod retracts into the hydraulic cylinder, it pulls the inner pressure block towards the outer pressure block, thereby clamping the vacuum chamber shell. One end of the lead screw is screwed into the threaded sleeve and connected to the threaded sleeve through a pressure spring, and the pressure spring is always in a compressed state. A groove is provided along the length direction on the surface of the lead screw, and the scale dimension line is at the bottom of the groove. A threaded shaft hole is provided in the core column, and a locking bolt is screwed into the threaded shaft hole to axially press the ring and fix the threaded sleeve.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention allows for the on-site machining of custom-made fixing blocks after the vacuum chamber outer shell is welded, based on the installation conditions of the joint area. These blocks are then beveled and welded to the outer shell splicing plate. Simultaneously, a groove is cut into the first shielding block for positioning and installation. The inner shielding block in the joint area adopts a split structure. While ensuring sufficient installation space in the joint area, the inner and outer shielding blocks are positioned with a gap using a gasket with a flange bushing (i.e., a bushing gasket). Finally, they are connected inside the vacuum chamber using fastening screws. The structure is easy to manufacture and the installation method is simple, requiring only common tools. Furthermore, wings are designed on the sides of the inner shielding block. After all shielding blocks are installed, the wings are welded to the vacuum chamber stiffeners on both sides of the joint area to further strengthen the fixed connection between the shielding block and the vacuum chamber.

[0028] More specifically, this invention addresses the assembly and welding errors inherent in the vacuum chamber sector sections, denoted as t millimeters. Positioning blocks are welded to the outer shell splicing plate in the vacuum chamber seam area. These positioning blocks can be machined on-site based on measurement results to ensure the mounting holes are aligned with the centerline of the seam area. This serves as the positioning of the outer shielding blocks and the fixation of the entire shielding block assembly. The inner shielding blocks are positioned using bushing washers, and fins are spot-welded for fixation. The entire assembly is then secured with fastening screws, and finally, the fins are corner-welded to the stiffening plate, completing the installation of one row of shielding blocks.

[0029] Compared to the traditional ITER, the requirements for measurement, processing, and precision are greatly reduced. The fixing points for the neutron shielding block are selected on the splicing plate of the vacuum chamber shell. The mounting blocks can be machined and adapted on-site, allowing the installation of the neutron shielding block in the joint area to be completed even with large errors in on-site vacuum chamber sector installation and welding. In addition, since the fixing points are on the outer shell splicing plate, the welding shrinkage during subsequent welding (inner shell welding) has minimal impact on it, reducing the deformation of the edge stiffeners of the vacuum chamber on both sides.

[0030] Other functions and features of the present invention will be described in detail in the following embodiments to provide a full understanding of the concept of the present invention and to enable its practical application in production. Attached Figure Description

[0031] Figure 1 This is a diagram showing the installation structure of the neutron shielding block in this invention.

[0032] Figure 2 A partial top view of the installation structure of the neutron shielding block when the misalignment is extremely small;

[0033] Figure 3 An exploded view of the neutron shielding block;

[0034] Figure 4 This is a schematic diagram of the offset edge of the vacuum chamber sector (with the inner and outer shells of the vacuum chamber offset accordingly) in the preferred embodiment;

[0035] Figure 5 The welding bevel form for the positioning block;

[0036] Figure 6 A top view schematic diagram of the assembly relationship of the neutron shielding block components in the joint area;

[0037] Figure 7 A cross-sectional schematic diagram of the assembly structure of the neutron shielding block assembly in the joint area;

[0038] Figure 8 This is a simplified top view of the misaligned clamping mechanism;

[0039] Figure 9 A schematic diagram illustrating the staggered installation of vacuum chamber sectors using a staggered clamping mechanism;

[0040] Figure 10 This is a side view of the mounting base;

[0041] Figure 11 for Figure 9 Enlarged view at point M;

[0042] Figure 12 This is a simplified three-dimensional structural diagram of a sector section of a vacuum chamber.

[0043] As shown in the figure, the vacuum chamber outer shell 1, the vacuum chamber inner shell 2, the outer shell splicing plate 3, the vacuum chamber edge stiffener 4, the neutron shielding block in the joint area 5, the outer shielding block 501, the inner shielding block 502, the first shielding block 50201, the second shielding block 50202, the vacuum chamber inner shell gap 6, the positioning block 7, the threaded hole 701, the fastening screw 8, the bushing washer 9, the wing 10, the screw hole 11, the spring washer 12, the fixing hole 13, the welding bevel 14, the fillet weld 15, the ring sleeve 16, the core column 17, the threaded sleeve 18, the lead screw 19, the inner pressure block 20, the piston rod 21, the outer pressure block 22, the hydraulic cylinder 23, the mounting base 24, the locking bolt 25, and the pressure spring 26. Detailed Implementation

[0044] Based on the accompanying drawings and the following description, the technical solutions in the embodiments of the present invention can be clearly and completely described. However, it should be understood that the embodiments mentioned herein are merely one or several specific methods of the present invention, and not all implementation structures or method steps.

[0045] In this embodiment, when installing the neutron shielding block in the joint area of ​​a compact fusion reactor vacuum chamber sector, the main installation logic is as follows: Between the vacuum chamber sectors of the fusion reactor, there is an area composed of a vacuum chamber interior, an outer shell, vacuum chamber edge stiffeners 4, and a splicing plate for the outer shell 1. The neutron shielding block 5 in the joint area is finally installed after the outer shell splicing plate 3 is welded, through the gap 6 between the inner and outer shells of the vacuum chamber, i.e., the gap between the two inner and outer shells 2. It should be noted that in this embodiment, if... Figures 1-2 The outer shell 1 of the vacuum chamber appears to be inside the inner shell 2 of the vacuum chamber, but it is named "outer shell" because the structure of the vacuum chamber sector is as follows: Figure 12 As shown, both the inner and outer shells of the vacuum chamber are arc-shaped. Therefore, relative to a certain vacuum chamber sector, the outer shell 1 is on the outside, hence the industry term "outer shell." Specifically, depending on the location of the vacuum chamber, the number of layers of the neutron shielding block 5 in the joint area varies. Taking the high-field side of the vacuum chamber as an example, in this embodiment, the outer shielding block 501 in the joint area neutron shielding block installation structure of a compact fusion reactor vacuum chamber sector is an integral structure with fixing holes 13 on its back for positioning the shielding block assembly. To meet the installation requirements in confined spaces, such as... Figure 1 , Figure 3 and Figure 6 The inner shielding block 502, located in the innermost layer, has a split structure; such as Figure 3 A screw hole 11 is provided on the inner shielding block 502 to accommodate the fastening screw 8, and as shown... Figure 3 On both sides of the inner shielding block 502, there are wings 10 for welding and fixing. In actual manufacturing, the inner shielding block 502 is as follows... Figure 3 and Figure 6 As shown, it includes a second shielding block 50202 and a first shielding block 50201. Both the second shielding block 50202 and the first shielding block 50201 have an L-shaped recessed platform structure on one side. The stepped surfaces of the two recessed platforms fit together, thereby enabling the assembly and splicing of the second shielding block 50202 and the first shielding block 50201. Moreover, the fastening screw 8 passes vertically through the recessed platform structure, that is, the fastening screw 8 is optimally located on the aforementioned center line. Correspondingly, the second shielding block 50202 and the first shielding block 50201 each have wings 10 on the side away from the recessed platform structure.

[0046] Specifically, the installation method of the neutron shielding block mounting structure in the joint area of ​​the vacuum chamber sector of the compact fusion reactor in this embodiment is as follows: Figure 4Considering the inevitable assembly and welding errors between vacuum chamber sectors, and assuming a pre-set error of t, it is best to set the misalignment of the vacuum chamber sectors on both sides of the joint area to t=20mm during actual installation and welding. This means that in the two opposing vacuum chamber shells 1 on both sides of the joint area, the misalignment of the first vacuum chamber shell 1 beyond the other vacuum chamber shell 1 is 20mm, i.e., they are not on the same circumference. For example, the misalignment of the mating side of one vacuum chamber shell 1 beyond the mating side of the other vacuum chamber shell 1 is 20mm. As for the shell splicing plate 3 between the two vacuum chamber shells 1, it can be customized based on reverse engineering measurements, ideally ensuring that the bevels used for welding on both sides of the vacuum chamber shell 1 are consistent.

[0047] Based on the above installation structure and method, when setting the two vacuum chamber sectors on both sides of the joint area of ​​the vacuum chamber sector, this embodiment recommends using a staggered clamping mechanism. This staggered clamping mechanism mainly includes: a first clamping arm assembly and a second clamping arm assembly for clamping the outer shells 1 of two adjacent vacuum chambers respectively. The second clamping arm assembly is axially slidably installed inside the first clamping arm assembly, and the two are at a certain angle to each other. Moreover, a core column 17 perpendicular to the first clamping arm is fixed on the first clamping arm. Figure 8 As shown, a ring 16 is coaxially rotatably mounted on the outside of the core column 17. A threaded sleeve 18 is radially fixed on the cylindrical surface of this ring 16. A lead screw 19 is coaxially threaded into the free end of the threaded sleeve 18. The lead screw 19 can be screwed into or out of the threaded sleeve 18. Furthermore, a scale line is provided on the lead screw 19 along its length to indicate the length of the lead screw 19 extending outwards. In practical use, two adjacent vacuum chamber shells 1 can be clamped together using two clamping arm assemblies. The first clamping arm assembly is fixed in place, while the second clamping arm assembly can slide relative to the first clamping arm assembly. Unscrew the lead screw 19 from the threaded sleeve 18 until its tip contacts the concave side of the first vacuum chamber shell near the joint area. Then continue rotating the threaded sleeve 18, for example, counterclockwise to an angle so that the end of the lead screw 19 leaves the first vacuum chamber shell. Continue unscrewing the lead screw 19 outwards by a length of t millimeters. Then continue rotating the threaded sleeve 18, for example, counterclockwise, until it slides to the concave side of the second vacuum chamber shell, i.e. Figure 9 As shown, when the screw 19 slides onto the concave side, it naturally pushes the second vacuum chamber shell and the second clamping arm assembly into place together, thus achieving the required misalignment amount of t millimeters for welding installation. At this point, the second clamping arm assembly is also fixed. Specifically, depending on the site conditions, it can be installed and fixed using methods such as tripods. For example, the first clamping arm assembly can be fixed to the ground in the construction area using tripods. Furthermore, to facilitate a smoother slide of the lead screw 19 onto the concave side of the second vacuum chamber shell, a chamfer can be made at the end of the lead screw 19, for example, a chamfer on the right side of the end of the lead screw 19.

[0048] For more details, please refer to [link / reference]. Figure 8 The two clamping arm assemblies described above each include a hydraulic cylinder 23, a piston rod 21, an outer pressure block 22, an inner pressure block 20, and a mounting base 24. The hydraulic cylinder 23 is mounted on one end of the mounting base 24. The piston rod 21 extends and retracts axially under the drive of the hydraulic cylinder 23; that is, the piston rod 21 is the main shaft for the extension and retraction of the hydraulic cylinder 23. The piston rod 21 is machined into an L-shape so that after passing over the corresponding vacuum chamber outer shell 1, the inner pressure block 20 is fixed at its downward-extending end, while the outer pressure block 22 is fixedly mounted on the bottom of the hydraulic cylinder 23. During installation, the hydraulic cylinder 23 is positioned where the outer pressure block 22 is against the concave side of the vacuum chamber outer shell 1. When the piston rod 21 retracts into the hydraulic cylinder 23, it pulls the inner pressure block 20 towards the outer pressure block 22, thereby clamping the vacuum chamber outer shell 1. Figure 11 One end of the lead screw 19, screwed into the threaded sleeve 18, is connected to the threaded sleeve 18 via a pressure spring 26. The pressure spring 26 is always compressed, thus maintaining a relatively stable position for the lead screw 19 and preventing it from easily rotating and stretching or shortening. A groove (not shown in the figure) is provided along the length of the lead screw 19, with a graduation line at the bottom of the groove to avoid the problem of graduation lines being inconvenient to set on the thread teeth. To fix the second clamping arm assembly to the first clamping arm assembly during final installation, it can be done as follows... Figure 10 As shown, the core post 17 has a threaded shaft hole, into which a locking bolt 25 is screwed to axially press the end face of the ring sleeve 16, thereby fixing the threaded sleeve 18, and in particular, fixing the mounting base 24 of the two clamping arm assemblies, so that the two mounting bases 24 become one.

[0049] In practice, after the welding of the splicing plates of the vacuum chamber shell 1 is completed, a positioning block 7 is customized and installed. A threaded hole 701 is drilled in the positioning block 7, and the axis of the threaded hole 701 is kept as close as possible to the center line of the vacuum chamber joint area. More specifically, a welding bevel 14 is drilled in the positioning block 7, and the welding bevel 14 is in the form of... Figure 5 As shown, based on the actual welding state of the outer shell splicing plate 3 on site, it can be considered that the welded outer shell splicing plate 3 may have some offset, for example, it is not strictly... Figure 2 If the ideal position is shown, the positioning block 7 can be machined on-site to ensure that the positioning block 7, or the aforementioned threaded hole 701, is on the center line of the joint area, and finally the positioning block 7 is welded to the outer shell splicing plate 3.

[0050] Continue to combine Figures 6-7 The installation of the neutron shielding block structure, as shown, mainly includes the following steps:

[0051] (1) The positioning block 7 is customized according to the measurement data. Specifically, the misalignment can be preset to t mm, and the outer shell splicing plate 3 is tilted to process the bevel of the end face of the positioning block 7. The above-mentioned threaded hole 701 for installation is opened on the positioning block 7, and the end of the positioning block 7 is machined to form the required welding bevel 14. Then, through the gap between two adjacent vacuum inner shells 2, one end of the positioning block 7 is welded to the outer shell splicing plate 3.

[0052] (2) Place the outer shielding block 501 at an angle into the joint area so that it can be smoothly placed into the joint area, and then install it onto the positioning block 7 after it is straightened. There are gaps between the outer shielding block 501 and the outer shell splicing plate 3 and the vacuum chamber edge stiffeners 4 on both sides.

[0053] (3) Install the washer with bushing on the outer shielding block 501, that is, insert one end of the washer with bushing into the fixing hole 13 on the outer shielding block 501.

[0054] (4) Place the inner shielding block 502 onto the bushing washer and spot weld the wings 10 on both sides of it to the edge stiffener 4 of the vacuum chamber. It should be noted that, in the specific manufacturing process, for the combined inner shielding block 502, the first shielding block 50201 of the inner shielding block 502 can be moved to the position where it is spliced ​​with the second shielding block 50202, and the spliced ​​inner shielding block 502 can be placed onto the bushing washer, i.e., the bushing washer 9. Then spot weld the wings 10 on both sides to fix the inner shielding block 502.

[0055] (5) Use fastening screws 8 to fix the innermost shielding block 502 onto the positioning block 7, thus completing the installation of a row of shielding blocks.

[0056] (6) Finally, the wing 10 is corner welded to the stiffening plates on both sides to complete the reinforcement and further improve the welding firmness.

[0057] In the above embodiments, as a compact fusion reactor, the spacing between the edge stiffeners 4 of the two vacuum chambers can be 260mm, the spacing between the outer shell 1 and the inner shell 2 of the vacuum chamber can be 110mm, and the width of the joint area between the two inner shells 2 of the vacuum chamber can be 180mm. When the welding bevel 14 is opened on the positioning block 7, the bevel angle is not less than 45°, and the bevel depth is 8~10mm. The thickness of the washer portion of the bushing gasket 9 is 5mm, that is, the thickness of the annular portion in the aforementioned embodiment is 5mm, and the length of the two ends of the bushing outside the gasket is not less than 5mm.

[0058] This invention is not limited to the field covered by this embodiment. Some well-known structures or principles have not been further described. However, those skilled in the art can theoretically know all the well-known technologies in this field prior to the application date or priority date, and can fully master all the prior art in this field. They also have the means and ability to apply these prior art in practical design. Under the technical guidance provided in this application, those skilled in the art can more comprehensively improve and implement this invention by combining their own capabilities. Furthermore, it should be noted that although the text and graphics of the above embodiments have shown specific implementation scenarios of the invention, those skilled in the art can make various obvious extensions and expansions to these embodiments without departing from the design concept of the invention, forming different embodiments. However, this does not affect the fact that the scope of protection of the invention is covered and embodied by the technical features of this claim and equivalent technical features.

Claims

1. A neutron shielding block installation structure for the joint area of ​​a sector section in a fusion reactor vacuum chamber, characterized in that, The system includes two vacuum chamber edge ribs (4) located between the inner shell (2) and the outer shell (1) of the vacuum chamber. The two sides of the vacuum chamber edge ribs (4) are connected to the inner shell (2) and the outer shell, respectively. An outer shell splicing plate (3) is fixed in the gap between the mating sides of the two adjacent outer shells (1) to connect the two outer shells (1). A positioning block (7) is fixed on the surface of the outer shell splicing plate (3) facing the gap (6) between the two inner shells. A shielding block assembly is fixed at one end of the positioning block (7) away from the outer shell splicing plate (3). The shielding block includes an outer shielding block (501) and an inner shielding block (502) that are facing each other and parallel to each other. A bushing gasket (9) is provided between the two shielding blocks to separate the two shielding blocks. It also includes a fastening screw (8), which passes axially through the two shielding blocks and the bushing washer (9) and is screwed into the end face of the positioning block (7) in a threaded fit; the inner shielding block (502) has wings (10) integrally formed on both sides, and the wings (10) are used to be fixedly connected to the two vacuum chamber edge stiffeners (4); The inner shielding block (502) includes a second shielding block (50202) and a first shielding block (50201). Both the second shielding block (50202) and the first shielding block (50201) have an L-shaped recessed platform structure on one side. The stepped surfaces of the two recessed platforms fit together to achieve the assembly and splicing of the second shielding block (50202) and the first shielding block (50201). The fastening screw (8) passes vertically through the recessed platform structure. The second shielding block (50202) and the first shielding block (50201) each have the wing (10) on the side away from the recessed platform structure.

2. The neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 1, characterized in that, The bushing gasket (9) includes a cylindrical body and an annular portion coaxially fixed to the outside of the body.

3. The neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 2, characterized in that, The main body and the annular portion are integrally formed, and the main body outside the two ends of the annular portion is vertically inserted into the outer shielding block (501) and the inner shielding block (502), respectively.

4. The neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 1, characterized in that, The positioning block (7) with a threaded hole (701) at one end is inserted into the outer shielding block (501).

5. An installation method for a neutron shielding block installation structure in the joint area of ​​a fusion reactor vacuum chamber sector as described in any one of claims 1-4, characterized in that, Follow these steps: S1. First install the outer shell splicing plate (3): Set the two vacuum chamber sectors on both sides of the joint area of ​​the vacuum chamber sector to be staggered, and set the stagger to 20mm. Place the outer shell splicing plate (3) between the two vacuum chamber outer shells (1) of the two vacuum chamber sectors, and then weld and fix it to the side of the corresponding vacuum chamber outer shell (1). S2. Based on the measurement data, a positioning block (7) is customized. A threaded hole (701) for installing the fastening screw (8) is opened on the positioning block (7), and a welding bevel (14) is machined. One end of the positioning block (7) is welded to the outer shell splicing plate (3) through the gap (6) between the inner and outer shells of the vacuum chamber. S3. Place the outer shielding block (501) into the joint area at an angle, and after aligning it inside the joint area, install it onto the positioning block (7). There are gaps between the outer shielding block (501) and the splicing plate and the vacuum chamber edge stiffeners (4) on both sides. S4. Install one end of the bushing washer (9) onto the outer shielding block (501); S5. Place the inner shielding block (502) on the bushing washer (9) and spot weld its wings (10) on both sides to the vacuum chamber edge stiffener (4). S6. Use screws to fix the inner shielding block (502) onto the positioning block (7) to achieve the installation and fixation of the inner and outer shielding blocks and complete the installation of a row of shielding blocks. S7. Weld the two edges on one side of the wing (10) to the edge stiffeners (4) of the two vacuum chambers to complete the reinforcement and fixation.

6. The installation method of the neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 5, characterized in that, The spacing between the edge stiffeners (4) of the two vacuum chambers is 260mm, the spacing between the outer shell (1) of the vacuum chamber and the inner shell (2) of the vacuum chamber is 110mm, and the width of the joint area between the two inner shells (2) of the vacuum chamber is 180mm.

7. The installation method of the neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 5, characterized in that, When a welding bevel (14) is made on the positioning block (7), the bevel angle is not less than 45° and the bevel depth is 8~10mm; the thickness of the bushing washer (9) is 5mm and the length of the bushing at both ends outside the washer is not less than 5mm.

8. The installation method of the neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 5, characterized in that, When setting the two vacuum chamber sectors on both sides of the joint area of ​​the vacuum chamber sector, a staggered clamping mechanism is used. The staggered clamping mechanism includes: a first clamping arm assembly and a second clamping arm assembly for clamping the outer shells (1) of two adjacent vacuum chambers respectively. The second clamping arm assembly is axially slidably installed in the first clamping arm assembly, and a core column (17) perpendicular to it is fixed on the first clamping arm. A ring sleeve (16) is coaxially rotatably installed on the core column (17). A threaded sleeve (18) is radially fixed on the cylindrical surface of the ring sleeve (16). A screw rod (19) is coaxially threaded into the free end of the threaded sleeve (18). A scale line is provided on the screw rod (19) along the length direction. In use, first use the two clamping arm assemblies to clamp the two adjacent vacuum chamber shells (1) and fix the first clamping arm assembly. Screw the lead screw (19) out of the threaded sleeve (18) until the top end contacts the part of the concave side of the first vacuum chamber shell near the joint area. Then continue to rotate the threaded sleeve (18), and after the end of the lead screw (19) leaves the first vacuum chamber shell, continue to screw the lead screw (19) outward, and the screwing length is t mm. Then continue to rotate the threaded sleeve (18) and slide it to the concave side of the second vacuum chamber shell, push the second vacuum chamber shell and the second clamping arm assembly to slide into place together. At this time, fix the second clamping arm assembly as well.

9. The installation method of the neutron shielding block installation structure in the joint area of ​​the fusion reactor vacuum chamber sector as described in claim 8, characterized in that, Both clamping arm assemblies include a hydraulic cylinder (23), a piston rod (21), an outer pressure block (22), an inner pressure block (20), and a mounting base (24). The hydraulic cylinder (23) is mounted on one end of the mounting base (24). The piston rod (21) extends and retracts axially under the drive of the hydraulic cylinder (23). The piston rod (21) is L-shaped. The inner pressure block (20) is fixed to the end of the piston rod (21). The outer pressure block (22) is fixedly mounted on the bottom of the hydraulic cylinder (23). When the piston rod (21) retracts into the hydraulic cylinder (23), it moves the inner pressure block (20) toward the outer pressure block (22), thereby clamping the vacuum chamber shell (1). One end of the lead screw (19) is screwed into the threaded sleeve (18) and connected to the threaded sleeve (18) through a pressure spring (26), and the pressure spring (26) is always in a compressed state; a groove is provided on the surface of the lead screw (19) along the length direction, and the scale dimension line is at the bottom of the groove; a threaded shaft hole is provided in the core column (17), and a locking bolt (25) is screwed into the threaded shaft hole to axially press the ring (16) and fix the threaded sleeve (18).

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