A kind of vacuum chamber block type cold screen assembly for star simulator and vacuum chamber cold screen

Abstract

A kind of for stellarator vacuum chamber block type cold shield assembly and vacuum chamber cold shield, belong to the technical field of magnetic confinement nuclear fusion equipment.The present application includes vacuum chamber body, and the outer wall of vacuum chamber body is provided with block type cooling assembly, and block type cooling assembly includes several cooling blocks, cooling block includes cooling panel, and the outer wall of cooling panel is distributed with groove, the inner wall of groove is fixedly connected with several serpentine cooling pipe, and the opposite side of several cooling panels with vacuum chamber body is all laid with MLI insulating material layer, through evenly arranged serpentine cooling pipe, can realize the heat exchange of whole area uniform, guide heat along the preset efficient path directional transmission, to quickly remove radiation heat, effectively improve the overall heat shielding efficiency, reduce the operating load of low-temperature system, eliminate local flow dead zone or short circuit phenomenon simultaneously, ensure the consistency and reliability of the entire annular cold shield surface cooling intensity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic confinement nuclear fusion devices, in particular to a segmented cold screen assembly for a stellarator vacuum chamber and a vacuum chamber cold screen. BACKGROUND

[0002] A stellarator is a magnetic confinement device that uses a three-dimensional twisted magnetic field generated entirely by external complex coils to confine high-temperature plasma for controlled nuclear fusion. The confinement magnetic field of the stellarator is generated entirely by external non-planar coils designed with care. These coils are usually arranged in a modular manner to generate a three-dimensional twisted magnetic field configuration through current, thereby effectively confining the plasma without inducing a strong toroidal current in the plasma. The core design goal is to achieve steady-state (continuous) operation of the fusion reaction, which is considered a key ideal feature of future commercial fusion energy systems.

[0003] As an important magnetic confinement nuclear fusion experimental device, the inner wall of the vacuum chamber of the stellarator needs to withstand the high heat load generated during plasma operation. To ensure the stable operation of key components such as superconducting magnets in a low-temperature environment, a cold screen assembly is usually provided on the outer wall of the vacuum chamber to shield radiation heat and achieve efficient cooling.

[0004] However, traditional cold screens are usually designed in a monolithic or large block segmented manner, which is difficult to adapt to the complex ring-shaped and irregular profile of the stellarator vacuum chamber, resulting in a deviation between the cooling panels and the vacuum chamber wall surface. The cooling flow path is often a single path or locally concentrated arrangement, and the cooling medium is unevenly distributed in the flow field, which easily forms local heat exchange blind areas, resulting in uneven temperature distribution on the surface of the cold screen, small gaps in the contact interface, and significant contact thermal resistance. This results in the radiation heat of the vacuum chamber wall surface being unable to be quickly and fully transferred to the cooling medium, low heat exchange efficiency, insufficient heat shielding performance of the cold screen, and increased operating load of the low-temperature system. SUMMARY

[0005] The purpose of the present application is to solve the problems raised in the prior art, and a segmented cold screen assembly for a stellarator vacuum chamber and a vacuum chamber cold screen are proposed.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a segmented cold screen assembly for a stellarator vacuum chamber, comprising a vacuum chamber body, the outer wall of the vacuum chamber body is provided with a segmented cooling assembly, and the segmented cooling assembly comprises a plurality of cooling segments;

[0007] The cooling segment comprises a cooling panel, and a groove is formed in the outer wall of the cooling panel, a plurality of serpentine cooling pipes are fixedly connected to the inner wall of the groove, and an MLI thermal insulation material layer is arranged between the opposite sides of the plurality of cooling panels and the vacuum chamber body, and is installed on the outer wall of the vacuum chamber body through a fixing structure.

[0008] Further, the inner surface of the cooling panel is a curved surface matched with the curvature of the outer wall of the vacuum chamber body, made of brass or oxygen-free copper, and provided with channel grooves distributed in the whole area on the inner side for carrying high-efficiency cooling channels.

[0009] Further, the serpentine cooling pipes are embedded in the outer wall grooves of the cooling panel by brazing and connected with the outer wall grooves of the cooling panel by brazing, and the serpentine cooling pipes are composed of a plurality of serpentine cooling pipes arranged at equal intervals along the length and width directions of the cooling panel.

[0010] Further, the MLI insulation material layer is a multi-layered aluminized polyimide film superposition structure, and a fiber spacing layer is arranged between adjacent layers.

[0011] Further, the outer wall of the vacuum chamber body is provided with a plurality of sub-block installation stations, and the sub-block installation stations are spaced apart along the circumferential and polar directions of the outer surface of the vacuum chamber body, each sub-block installation station is provided with a positioning reference surface and a fixing hole, and the inner part of the vacuum chamber body is provided with a rib plate.

[0012] Further, the fixing structure includes a bolt assembly penetrating through the cooling panel and screwed into the fixing hole, and the bolt assembly includes a G10 sleeve made of low thermal conductivity material and a gasket.

[0013] Further, the gasket is made of polytetrafluoroethylene, and the bolt assembly further includes a hexagonal bolt.

[0014] Further, each cooling sub-block is provided with four fixing structures, and the fixing structures are distributed in a rectangular shape.

[0015] A vacuum chamber cold screen, characterized in that it comprises a plurality of a kind of sub-block type cold screen assembly for a stellarator vacuum chamber.

[0016] Compared with the prior art, the above-mentioned scheme has the following beneficial effects:

[0017] 1. The heat generated by the stellarator during operation is conducted on the cooling panel, and then uniformly distributed serpentine cooling pipes are used to achieve uniform heat exchange in the whole area, so that the heat is mainly transferred along the designed efficient path, and the radiant heat can be quickly and directionally removed, thereby significantly improving the overall heat shielding efficiency, reducing the operating load of the low-temperature system, eliminating local flow dead zones or short circuits, ensuring the consistency of the cooling strength of the entire cold screen annular surface, and finally achieving the goal of controlling the temperature deviation of the cooling panel in the whole area within ±2K.

[0018] The serpentine cooling pipe is embedded in the groove in advance and fixed by brazing, so that the micro gap existing in the traditional mechanical contact is completely eliminated, a seamless conduction path is formed, and the contact thermal resistance is greatly reduced.

[0019] 2. By controlling the depth of the hexagonal bolt, the compression degree between the bottom end of the G10 sleeve and the wall surface of the vacuum chamber body can be finely adjusted, so that the cooling panel is prevented from being deformed or damaged due to excessive stress, and the fine adjustment capability allows the operator to reserve a certain compensation gap for the thermal expansion and contraction during the operation of the stellar simulator, so that the thermal stress caused by the new heat exchange blind area due to deformation is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The overall view of the vacuum chamber and the cold shield according to the present application is shown in the figure.

[0021] Figure 2 The partial view of the vacuum chamber and the cold shield according to the present application is shown in the figure.

[0022] Figure 3 The partial exploded view of the vacuum chamber and the cold shield according to the present application is shown in the figure.

[0023] Figure 4 The block diagram of the cooling panel according to the present application is shown in the figure.

[0024] Figure 5 The sectional view of the fixing structure according to the present application is shown in the figure.

[0025] The marks in the figure are: 500, vacuum chamber body; 510, block installation station; 511, fixing hole; 520, rib plate; 800, block type cooling assembly; 810, cooling block; 811, cooling panel; 812, serpentine cooling pipe; 813, MLI thermal insulation material layer; 814, fixing structure; 8141, G10 sleeve; 8142, gasket; 8143, hexagonal bolt. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0027] In the description of the present application, it should be understood that the terms "upper", "lower", "top surface", "bottom surface" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the positions or elements referred to must have a particular orientation, be formed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only used to distinguish entities or operations from each other, and do not require or imply any actual relationship, order or relative importance between them.

[0028] Embodiment one, please refer to Figures 1-4 A kind of for star simulator vacuum chamber block type cold screen subassembly, including vacuum chamber body 500, the outer wall of vacuum chamber body 500 is provided with block type cooling assembly 800, and block type cooling assembly 800 includes several cooling blocks 810.

[0029] Cooling block 810 includes cooling panel 811, and the outer wall of cooling panel 811 is distributed with recess, and the inner wall of recess is fixedly connected with several serpentine cooling pipes 812, and the opposite sides of several cooling panels 811 with vacuum chamber body 500 are both paved with MLI heat insulation material layer 813, and are installed on the outer wall of vacuum chamber body 500 by fixed structure 814, the inner surface of cooling panel 811 is the curvature of the outer wall of vacuum chamber body 500, which is made of brass or oxygen-free copper, and the inner side is provided with a globally distributed channel slot for carrying high-efficiency cooling channel, and several cooling panels 811 are spliced to form a complete annular cooling surface along the ring direction.

[0030] Further, several serpentine cooling pipes 812 are embedded in the outer wall recess of cooling panel 811 by brazing, and are connected with the outer wall recess of cooling panel 811 by brazing, and the serpentine cooling pipe 812 is composed of a plurality of serpentine cooling pipes 812 arranged at equal intervals along the length and width directions of the cooling panel 811, the MLI heat insulation material layer 813 is a multi-layer aluminized polyimide film superposition structure, and a fiber spacing layer is arranged between adjacent layers, and the inside of the vacuum chamber body 500 is provided with a rib plate 520, and a cooling medium flow channel is formed in the inside of the vacuum chamber body 500 by the rib plate 520.

[0031] In the embodiment, the vacuum chamber body 500 is integrally formed by 3D printing, and the block mounting station 510 is pre-set on the outer wall to provide a positioning reference surface without splicing error, and during assembly, the multiple cooling panels 811 are aligned and mounted with the reference surface of the corresponding block mounting station 510, which ensures that the inner surface of all cooling blocks 810 after splicing is tightly fitted with the complex curved outer wall of the vacuum chamber, and eliminates the large-area air gap caused by traditional splicing error.

[0032] The multi-section parallel serpentine cooling channels are assembled to form the serpentine cooling pipe 812, which constitutes a uniform circulation route. Heat is conducted from the cooling panel 811 to the wall of the serpentine cooling pipe 812, which is seamlessly combined with the cooling panel 811. The MLI insulation layer 813 laid between the vacuum chamber body 500 and the cooling panel 811 can effectively ensure that the cooling panel 811 is attached to the inner wall of the vacuum chamber body 500 without a blind space, avoiding the formation of an air layer. The cooling medium flow channel in the vacuum chamber body 500 formed by the rib plate 520 circulates the cooling medium directly against the main plasma heat load, so that the body temperature of the vacuum chamber body 500 is effectively controlled at a relatively low and stable level.

[0033] When the stellarator is in operation, heat generated by the stellarator is transferred outward from the wall of the vacuum chamber body 500 by radiation and conduction, absorbed by the cooling panel 811 made of high-thermal-conductivity brass or oxygen-free copper, and flows into the cooling panel 811 from the external main pipeline. Inside each cooling block 810, the cooling medium is divided into multiple parallel serpentine cooling pipes 812 arranged at equal intervals in the length and width directions of the panel. The cooling medium uniformly flows through the surface area of the cooling panel 811, and is then rapidly removed by the cooling medium flowing in the pipes through convective heat exchange. The uniform arrangement achieves uniform heat exchange throughout the entire panel, and heat is mainly transferred along the designed efficient path, so that the radiant heat can be quickly and directionally removed, thereby significantly improving the overall heat shielding efficiency and reducing the operating load of the low-temperature system. This eliminates local flow dead zones or short circuits and ensures the consistency of the cooling strength of the entire cold screen annular surface, ultimately achieving the goal of controlling the temperature deviation of the entire cooling panel 811 within ±2K.

[0034] The serpentine cooling pipes 812 are pre-embedded in the grooves and fixed by brazing. This connection method completely eliminates the micro gaps existing in traditional mechanical contact, forms a seamless conduction path, and greatly reduces the contact thermal resistance.

[0035] Example Two, please refer to Figures 1-5 On the basis of Example One, in this embodiment, the outer wall of the vacuum chamber body 500 is provided with a plurality of block installation stations 510, which are spaced apart along the circumferential and polar directions of the outer surface of the vacuum chamber body 500. Each block installation station 510 is provided with a positioning reference surface and a fixing hole 511.

[0036] Further, the fixing structure 814 includes a bolt assembly passing through the cooling panel 811 and screwed into the fixing hole 511, the bolt assembly including a G10 sleeve 8141 made of low thermal conductivity material and a gasket 8142 made of polytetrafluoroethylene, and the bolt assembly further including a hexagonal bolt 8143, and four fixing structures 814 are arranged in a rectangular distribution corresponding to each cooling block 810.

[0037] In the embodiment, when assembling the cooling blocks 810, first, the cooling blocks 810 are sequentially placed on the positioning reference surface of the block mounting station 510, then the hexagonal bolt 8143 and the G10 sleeve 8141 are fixed together, the opening of the MLI thermal insulation material layer 813 of the cooling panel 811 is passed, and finally the hexagonal bolt 8143 is screwed into the fixing hole 511 of the block mounting station 510 at the outer wall of the vacuum chamber body 500 to complete the assembly, and in the process, the gasket 8142 is placed below the G10 sleeve 8141, and the gasket 8142 serves to isolate the surface of the cooling panel 811 from direct contact with the hexagonal bolt 8143 and utilizes the soft material characteristics to produce a certain sealing and stress buffering effect during tightening.

[0038] By controlling the depth of the hexagonal bolt 8143 screwed in, the compression degree between the bottom end of the G10 sleeve 8141 and the wall surface of the vacuum chamber body 500 can be fine-tuned to avoid deformation or damage of the cooling panel 811 due to excessive stress, and the fine-tuning capability allows the operator to reserve a certain compensation gap for the thermal expansion and contraction effect during the operation of the stellar simulator to avoid new heat exchange blind areas due to deformation to cause thermal stress to damage the components.

[0039] The working principle of the present application is as follows: when assembling, first, the cooling blocks 810 are sequentially placed on the positioning reference surface of the block mounting station 510, then the hexagonal bolt 8143 and the G10 sleeve 8141 are fixed together, the opening of the MLI thermal insulation material layer 813 of the cooling panel 811 is passed, and finally the hexagonal bolt 8143 is screwed into the fixing hole 511 of the block mounting station 510 at the outer wall of the vacuum chamber body 500 to complete the assembly, and in the process, the gasket 8142 is placed below the G10 sleeve 8141, and the gasket 8142 serves to isolate the surface of the cooling panel 811 from direct contact with the hexagonal bolt 8143 and utilizes the soft material characteristics to produce a certain sealing and stress buffering effect during tightening.

[0040] By controlling the depth of the hexagonal bolt 8143 screwed in, the compression degree between the bottom end of the G10 sleeve 8141 and the wall surface of the vacuum chamber body 500 can be fine-tuned to avoid deformation or damage of the cooling panel 811 due to excessive stress, and the fine-tuning capability allows the operator to reserve a certain compensation gap for the thermal expansion and contraction effect during the operation of the stellar simulator to avoid new heat exchange blind areas due to deformation to cause thermal stress to damage the components.

[0041] Through the assembly of the multiple parallel serpentine cooling channels, the serpentine cooling pipe 812 constitutes a uniform circulation route, heat is conducted from the cooling panel 811 to the wall of the serpentine cooling pipe 812 which is seamlessly combined with the cooling panel 811, and the uniform adhesion of the cooling panel 811 to the inner wall of the vacuum chamber body 500 is effectively ensured by the MLI insulation material layer 813 laid between the vacuum chamber body 500 and the cooling panel 811, so as to avoid the formation of an air layer, and the cooling medium flow channel in the vacuum chamber body 500 formed by the rib plate 520, the circulating cooling medium directly deals with the main plasma heat load, so that the body temperature of the vacuum chamber body 500 is effectively controlled at a relatively low and stable level;

[0042] After the star simulator works, the heat generated by the star simulator is transferred outward from the wall of the vacuum chamber body 500 by radiation and conduction, is absorbed by the cooling panel 811 made of high-thermal-conductivity brass or oxygen-free copper, flows into the cooling panel 811 from the external main pipeline, is branched into multiple parallel serpentine cooling pipes 812 which are arranged in a serpentine manner at equal intervals in the length and width directions of the panel, so that the cooling medium uniformly flows through the surface area of the cooling panel 811, and then is rapidly taken away by the cooling medium flowing in the pipes through convective heat exchange, so that the heat is mainly transferred along the designed efficient path, the radiant heat can be quickly and directionally removed, the overall heat shielding efficiency is significantly improved, the operation load of the low-temperature system is reduced, the local flow dead zone or short circuit is eliminated, the consistency of the cooling strength of the entire cold shield annular surface is ensured, and finally the goal of controlling the temperature deviation of the entire cooling panel 811 within ±2K is achieved.

[0043] The serpentine cooling pipe 812 is embedded in the groove in advance and fixed by brazing, so that the micro gaps existing in the traditional mechanical contact are completely eliminated, a seamless conduction path is formed, and the contact thermal resistance is greatly reduced.

[0044] It should be noted that the devices in the present application are common market devices, which can be selected according to the needs during specific use, and the circuit connection relationship of each device is a simple series and parallel connection circuit, and there is no innovation point in the circuit connection part, which can be easily realized by those skilled in the art and belongs to the prior art, and will not be described in detail.

[0045] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A modular cold shield assembly for a stellarator vacuum chamber, comprising a vacuum chamber body (500), characterized in that: The outer wall of the vacuum chamber body (500) is provided with a segmented cooling assembly (800), and the segmented cooling assembly (800) includes a plurality of cooling blocks (810); The cooling section (810) includes a cooling panel (811), and the outer wall of the cooling panel (811) is provided with grooves. The inner wall of the grooves is fixedly connected with a plurality of serpentine cooling pipes (812). MLI insulation material layer (813) is laid between the opposite sides of the cooling panels (811) and the vacuum chamber body (500), and is installed on the outer wall of the vacuum chamber body (500) by a fixing structure (814). The inner surface of the cooling panel (811) is a curved surface adapted to the curvature of the outer wall of the vacuum chamber body (500). Made of brass, the inner side is provided with channel grooves distributed throughout the entire area to support high-efficiency cooling channels. Several cooling panels (811) are spliced ​​together in the circumferential direction to form a complete annular cooling surface. Several serpentine cooling pipes (812) are brazed into the grooves on the outer wall of the cooling panel (811) and are connected to the grooves on the outer wall of the cooling panel (811) by brazing. The serpentine cooling pipes (812) are composed of multiple serpentine cooling pipes (812) arranged at equal intervals along the length and width of the cooling panel (811). By assembling, the multiple parallel serpentine cooling channels and serpentine cooling pipes (812) form a uniform circulation route. Heat is conducted from the cooling panel (811) to the wall of the serpentine cooling pipes (812) that are seamlessly connected to it. The MLI insulation material layer (813) laid between the vacuum chamber body (500) and the cooling panel (811) can effectively ensure that the cooling panel (811) and the inner wall of the vacuum chamber body (500) are in close contact without blind spots, avoiding the formation of air gaps. The cooling medium flow channel inside the vacuum chamber body (500) formed by the ribs (520) directly deals with the most important plasma heat load, so that the body temperature of the vacuum chamber body (500) is effectively controlled at a relatively low and stable level. When the stellarator is working, the heat it generates is transferred outward from the wall of the vacuum chamber body (500) through radiation and conduction. It is absorbed by the cooling panel (811) made of high thermal conductivity brass or oxygen-free copper. The cooling medium flows in from the external main pipeline and is diverted into multiple parallel serpentine cooling pipes (812) with equal spacing in the length and width of the panel inside each cooling section (810). This allows the cooling medium to flow evenly across the surface area of ​​the cooling panel (811). The cooling medium is then quickly carried away by the cooling medium flowing in the pipes through convection heat transfer. The uniform arrangement achieves uniform heat exchange throughout the entire area, allowing the heat to be transferred mainly along the designed efficient path. This enables the radiant heat to be removed quickly and directionally, thereby significantly improving the overall thermal shielding efficiency, reducing the operating load of the cryogenic system, eliminating local flow dead zones or short circuits, ensuring the consistency of the cooling intensity of the entire annular surface of the cold shield, and ultimately achieving the goal of controlling the temperature deviation of the entire cooling panel (811) within ±2K.

2. The segmented cold shield assembly for a stellarator vacuum chamber according to claim 1, characterized in that, The MLI insulation material layer (813) is a multilayer aluminum-plated polyimide film stacked structure with fiber spacer layers between adjacent layers.

3. A segmented cold shield assembly for a stellarator vacuum chamber according to claim 1, characterized in that, The outer wall of the vacuum chamber body (500) is provided with a number of segmented installation stations (510). The segmented installation stations (510) are distributed in a circumferential and polar direction along the outer surface of the vacuum chamber body (500). Each segmented installation station (510) is provided with a positioning reference surface and a fixing hole (511). The interior of the vacuum chamber body (500) is provided with stiffening plates (520), which form a cooling medium flow channel inside the vacuum chamber body (500).

4. A segmented cold shield assembly for a stellarator vacuum chamber according to claim 3, characterized in that, The fixing structure (814) includes a bolt assembly that passes through the cooling panel (811) and is screwed into the fixing hole (511), the bolt assembly including a G10 sleeve (8141) and a gasket (8142) made of a low thermal conductivity material.

5. A segmented cold shield assembly for a stellarator vacuum chamber according to claim 4, characterized in that, The gasket (8142) is made of polytetrafluoroethylene, and the bolt assembly also includes a hexagonal bolt (8143).

6. A segmented cold shield assembly for a stellarator vacuum chamber according to claim 5, characterized in that, Each of the cooling blocks (810) is provided with four fixed structures (814), which are arranged in a rectangular shape.

7. A vacuum chamber cooling shield, characterized in that, Includes multiple segmented cold shield assemblies for stellarator vacuum chambers according to any one of claims 1-6.

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