A superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process

Abstract

The present invention discloses a superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process. The superconducting coil includes a stack of multiple layers of sub-unit coils, each layer of sub-unit coils is provided with two coil joints, and the joints of adjacent layers are staggered to form a spirally ascending conductive structure. The stacking process is based on the leveling support platform, and the coil posture adjustment is achieved through replaceable fixtures: the coil is first fixed with the first fixture and the contour and joint position are detected, and the second fixture is replaced after passing the inspection; during hoisting, the characteristic line alignment technology is used to position the coil, and the contour is adjusted using a conformal tool or the circumferential adjustment device is used to fine-tune the angle to ensure precise alignment between layers; the circumferential adjustment device corrects the angle deviation through a telescopic column. This solution achieves assembly precision control of the superconducting coil stack through multi-level precision control, solves the problems of misalignment and poor conduction between large-sized coil layers, and improves the magnetic field uniformity and operational stability of the tokamak device.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear fusion superconducting coils, and in particular relates to a superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process. Background Art

[0002] The poloidal field coils (PF coils) in a tokamak are crucial components for controlling plasma configuration, stability, and current drive. They generate a magnetic field perpendicular to the toroidal direction of the plasma, forming a poloidal magnetic field. This, combined with the toroidal field generated by the toroidal field coils, creates a helical structure in the magnetic field lines, thereby confining the high-temperature plasma.

[0003] Due to space limitations, conventional superconducting coils cannot be wound indefinitely. Therefore, multiple layers of sub-unit coils must be stacked to form the final poloidal field coil. The stacked superconducting coils then undergo a subsequent vacuum pressure impregnation (VPI) process for integrated glue injection. This requires ensuring the stacking accuracy meets high standards and precision requirements. However, the large size (up to 10 meters in diameter) and heavy weight (tens or even hundreds of tons) of superconducting coils present significant challenges in achieving this precision. Summary of the Invention

[0004] The purpose of the present invention is to provide a superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process, so as to solve the problems in the prior art.

[0005] To this end, the present invention provides a superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process, comprising:

[0006] A superconducting coil is designed, comprising: a multi-layer subunit coil;

[0007] Coil connectors: Each sub-unit coil is provided with two coil connectors, and the coil connectors of two adjacent layers of sub-unit coils are connected in an interlaced manner, so that the current forms a spirally ascending conductive structure along the stacking direction.

[0008] As a preferred technical solution, the surface of the sub-unit coil is paved with at least one layer of glass fiber cloth.

[0009] A tokamak device is designed, comprising the superconducting coil described in any one of the above items.

[0010] A process for stacking superconducting coils according to any one of the above items is designed, comprising:

[0011] Leveling the support platform and marking characteristic lines on the support platform;

[0012] The sub-unit coil is fixed with a plurality of first clamps along the circumferential direction, and the sub-unit coil is lifted and kept in horizontal movement by the lifting fixture and placed on the support platform;

[0013] Measure the sub-unit coil contour and coil joint position. If they meet the preset requirements, proceed to the next step; if not, perform correction until the preset requirements are met.

[0014] Replacing the plurality of first clamps outside the subunit coils with second clamps, and connecting the hanger to the second clamps;

[0015] Using a hoist, the second fixture and the sub-unit coil are lifted by a preset distance, and the characteristic line on the sub-unit coil is compared with the characteristic line on the support platform. If there is a deviation, the sub-unit coil profile is adjusted using a conformal tool or the angle of the sub-unit coil is adjusted using a circumferential tool until the characteristic line of the sub-unit coil is aligned with the characteristic line of the support platform, and the coil is dropped to complete the stacking of the sub-unit coils.

[0016] Repeat the above steps until all sub-unit coils are stacked.

[0017] As a preferred technical solution, the step of circumferentially adjusting the subunit coils includes:

[0018] After the sub-unit coil is hoisted, the circumferential adjustment device provided on the support platform adjusts the column to abut against the main frame of the second fixture, and the circumferential rotation angle of the sub-unit coil is adjusted by controlling the extension length of the adjustment column.

[0019] As a preferred technical solution, after completing the hoisting of each layer of the sub-unit coils, the second clamp is removed;

[0020] The second clamp includes a clamp body clamped on the side and upper surface of the sub-unit coil, and a steel belt is arranged around the bottom of the clamp body, and the steel belt surrounds the lower surface of the sub-unit coil. When removing the second clamp, the steel belt is cut and pulled out.

[0021] As a preferred technical solution, after the second clamp is removed, the actual height of the superconducting coil is obtained using a measuring tool, and then glass cloth is laid, and the sub-unit coil is pressed to a preset height using a pressing tool.

[0022] As a preferred technical solution, the step of laying the glass cloth includes:

[0023] Clean the surface of the subunit coil and lay at least one layer of glass cloth until the thickness of the laid glass cloth is the same as the preset height requirement.

[0024] As a preferred technical solution, the step of adjusting the contour of the sub-unit coil by the conformal tool includes:

[0025] The position where the contour of the sub-unit coil deviates is determined, and the quick clamp in the shape-keeping tool at the position is pressed so that the pressure block at the end of the quick clamp squeezes the side surface of the sub-unit coil to adjust the contour.

[0026] As a preferred technical solution, a plurality of guide tools are provided along the circumferential outer edge of the support platform, and the guide tools are used to limit the falling position of the sub-unit coil.

[0027] Beneficial effects:

[0028] 1. The present invention provides a superconducting coil, a tokamak device utilizing the same, and a superconducting coil stacking process. A horizontally leveled support platform establishes a baseline, and a replaceable sub-unit coil fixture is used to achieve coil posture conversion. This technology combines profile detection with characteristic line alignment to ensure the positioning accuracy of the inter-layer sub-unit coils. Furthermore, a circumferential adjustment device uses telescopic adjustment columns to fine-tune the coil angle. A second fixture utilizes a removable steel belt at the bottom, compression compensation, and glass fiber cloth filling to achieve dynamic height compensation, enabling precise control of the assembly accuracy of multiple layers of superconducting coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a schematic structural diagram of the superconducting coil provided by the present invention.

[0031] Figure 2 The stacking process flow chart provided by the present invention.

[0032] Figure 3 This is a schematic structural diagram of the shape-preserving tool and the pressing tool in the stacking process provided by the present invention. DETAILED DESCRIPTION

[0033] The present invention may be more readily understood by referring to the following detailed description of preferred embodiments of the present invention and the included Examples. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. In the event of a conflict, the definitions in this specification shall prevail.

[0034] The present invention provides a superconducting coil, a tokamak device using the superconducting coil, and a superconducting coil stacking process, which solves the problem in the prior art that when stacking sub-unit coils of large-sized and heavy superconducting coils, the sub-unit coils between adjacent layers cannot be accurately aligned, affecting the accuracy of the superconducting coil stacking and the subsequent VPI process.

[0035] The technical concept of this invention lies in: first, establishing a reference through a horizontally leveled support platform, utilizing interchangeable sub-unit coil fixtures to achieve coil position conversion, and combining profile detection with characteristic line alignment technology to ensure the positioning accuracy of the sub-unit coils between layers. Furthermore, a circumferential adjustment device, using telescopic adjustment columns, fine-tunes the coil angle. Furthermore, a second fixture achieves dynamic height compensation using a removable steel belt at the bottom, compression compensation, and glass fiber cloth filling. This creates a closed-loop control system of "lifting-testing-adjustment-tightening," enabling precise control of the assembly of multiple layers of superconducting coils.

[0036] like Figure 1 As shown, a superconducting coil 100 includes multiple layers of sub-unit coils 110. Each layer of sub-unit coils 110 is a pancake-shaped structure formed by winding. A connector is provided at each end of each sub-unit coil 110. It can be understood that the sub-unit coils 110 are wound from a linear superconducting conductor, so the sub-unit coils 110 have two ends. To ensure that two adjacent layers of sub-unit coils 110 can be connected, coil connectors 120 are required at both ends of a single layer of sub-unit coils 110. The coil connectors 120 of two adjacent layers of sub-unit coils 110 are staggered, allowing the current to form a spirally ascending conductive structure along the stacking direction.

[0037] The present application also provides a tokamak device, which includes the above-mentioned superconducting coil 100, wherein there is more than one superconducting coil 100, and multiple superconducting coils 100 can be provided as needed to meet actual needs.

[0038] refer to Figure 2 , a stacking process of a superconducting coil 100, comprising:

[0039] The support platform 300 is leveled and a characteristic line is marked on the support platform 300. Before leveling the support platform 300, the support platform 300 needs to be installed. In some embodiments, the support platform 300 includes multiple lifting platforms that form a circle to support the superconducting coil 100. The entire support platform 300 is equipped with a wireless touch screen, which can control the lifting and lowering of any lifting platform.

[0040] Optionally, each lifting platform includes a support frame with a servo lift mounted at the bottom of the support frame and a pad mounted on the surface of the support frame. The support frame and the servo lift are connected by screws to prevent damage to the servo lift from large lateral forces applied to the coils during the correction process. In some embodiments, by adjusting the installation position of the lift screws, the stacking requirements of superconducting coils 100 of different sizes can be accommodated.

[0041] The leveling of the support platform 300 can be determined by a laser tracker, and characteristic lines can be marked on the support platform 300. Specifically, an easily observable longitudinal line, such as a red characteristic line, can be marked at a visible position on the side of the support frame.

[0042] In summary, the lifting platform provides a stacking work area for the superconducting coil 100, and the liftable design provides a reference surface for stacking, providing a basis for controlling tolerances in subsequent dimensional measurements, while also meeting the need to disassemble the fixture for subsequent insulation wrapping.

[0043] The sub-unit coil 110 is fixed with a plurality of first clamps 200 along the circumference, and the sub-unit coil 110 is hoisted horizontally by the hoist, and is guided by the guide mechanism to be accurately positioned on the support platform 300. Specifically, Figure 1 As shown, the first clamp 200 includes four clamps on the upper, lower, left and right sides, and the clamps can be fixed by bolts. The gap between the upper and lower clamps can be adjusted according to the number of layers of the sub-unit coil 110 to meet the needs. For example, when the first clamp 200 is clamping a single sub-unit coil 110 as described above, the gap between the upper and lower clamps can be adjusted to match the thickness of the single-layer coil. Before hoisting, the wire rope of the hoist is connected to the first clamp 200. The entire sub-unit coil 110 is kept horizontal by the basket screws on the hoist. It is hoisted to the top of the stacking platform, that is, the support platform 300, and a guide mechanism is provided on the outer circumference of the support platform 300. By adjusting the sub-unit coil 110, it slowly descends within the range of the guide structure until it falls on the support platform 300 or on multiple pads on the upper surface of the sub-unit coil 110 of the next layer. Preferably, the pads are G10 pads.

[0044] Optionally, the guide mechanism is installed about 2 mm from the outer contour of the coil, that is, a 2 mm gap is retained between the guide mechanism and the coil to avoid friction damage.

[0045] Measure the contour of the sub-unit coil 110 and the position of the coil connector 120. If the preset requirements are met, proceed to the next step; if not, perform correction until the preset requirements are met. Specifically, the contour correction of the sub-unit coil 110 can be performed as follows: Figure 3The correction is performed using the conformal tool 400 shown. The conformal tool 400 comprises a base 410, a quick-action clamp 460, and a pressure block 420. By tightening the quick-action clamp 460, the pressure block 420 applies pressure to the outer contour of the subunit coil 110, adjusting its contour and achieving correction. The coil connector 120 can be corrected along its circumference using the tool.

[0046] Optionally, the pressing block 420 is a G10 block. G10 is a composite material made of glass fiber cloth and epoxy resin through high temperature and high pressure lamination, which has the advantages of high strength, insulation, temperature resistance, corrosion resistance, lightness and machinability.

[0047] The multiple first clamps 200 outside the sub-unit coil 110 are replaced with second clamps, and the hoist is connected to the second clamp. The first clamp 200 is a traditional clamp. If the traditional clamp is used to lift the sub-unit coil 110 and place it on the upper surface of the next layer of sub-unit coil 110, the clamp cannot be removed, affecting the normal stacking of the superconducting coil 100. By replacing the first clamp 200 with a second clamp, the second clamp includes a main frame, and a steel belt is arranged around the bottom of the main frame. During lifting, the steel belt is wrapped around the lifted sub-unit coil 110. After the stacking is completed, the steel belt is cut and pulled out from one end. This effectively solves the problem that the traditional clamp cannot be removed after stacking is completed and cannot meet the stacking requirements.

[0048] Use a hoist to lift the second fixture and the sub-unit coil 110 by a preset distance, and compare the characteristic line on the sub-unit coil 110 with the characteristic line on the support platform 300. If there is a deviation, adjust the contour of the sub-unit coil 110 using the conformal tool 400 or adjust the angle of the sub-unit coil 110 using the circumferential tool until the characteristic line of the sub-unit coil 110 is aligned with the characteristic line of the support platform 300. Then, drop the coil to complete the stacking of the sub-unit coils 110.

[0049] Among them, the step of circumferentially adjusting the sub-unit coil 110 includes, after the sub-unit coil 110 is lifted, adjusting the column of the circumferential adjustment device provided on the support platform 300 to abut against the main frame of the second clamp, and adjusting the circumferential rotation angle of the sub-unit coil 110 by controlling the extension length of the adjustment column, so that the characteristic line on the sub-unit coil 110 is aligned with the support line on the next layer of sub-coil unit or the support platform 300. Specifically, whether it is aligned can be determined by a laser tracker.

[0050] The above steps are repeated until all sub-unit coils 110 are stacked.

[0051] Optionally, after the second clamp is removed, the glass cloth is laid after obtaining the actual height of the superconducting coil 100 using a measuring tool, and the sub-unit coil 110 is pressed to a preset height by using a pressing tool. It should be noted that the above is a case where the measured height is greater than or equal to the preset height. In another case, when the measured height is less than the preset height, the glass cloth can be laid directly without the need for a pressing tool. The step of laying the glass cloth on each layer of the sub-unit coil 110 includes: cleaning the surface of the sub-unit coil 110, and laying at least one layer of glass cloth until the thickness of the laid glass cloth is the same as the preset height requirement. Due to the weight of the sub-unit coil 110, the overall height of the coil after stacking is less than the preset height. However, since the subsequent VPI mold is manufactured in advance according to the preset dimensions, this will cause a large gap between the sub-unit coil 110 and the VPI mold. During the glue injection process, this gap will form a pure glue area, resulting in poor mechanical properties of the superconducting coil 100 after VPI, thereby affecting the superconducting performance of the entire superconducting coil 100 and even causing huge losses.

[0052] By laying the glass fiber cloth, on the one hand, it can achieve an insulating effect, and on the other hand, it can also compensate for the height difference between the preset height and the actual height, avoid the generation of a pure glue area, and improve the superconducting performance of the superconducting coil 100.

[0053] like Figure 3 As shown, optionally, a clamping tool is provided above the shape-preserving tool 400. The clamping tool includes a horizontal plate 440 placed horizontally above the coil. A threaded hole is provided at the center of the horizontal plate 440. A screw is threadedly connected to the threaded hole. The lower end of the threaded screw 430 is connected to a clamping plate 450. The clamping tool can be used to limit the height of the coil to maintain the shape and can also assist in determining whether the laying thickness of the glass fiber cloth between the sub-unit coils 110 is reasonable. Optionally, a tightening head is reserved at the upper end of the threaded screw 430, and the clamping plate 450 can be quickly lowered using a screw gun.

[0054] Optionally, the pressing plate 450 is a G10 plate. G10 is a composite material made of glass fiber cloth and epoxy resin through high temperature and high pressure lamination. It has the advantages of high strength, insulation, temperature resistance, corrosion resistance, lightness and machinability.

[0055] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A superconducting coil stacking process, characterized in that: The superconducting coil comprises: a multi-layer sub-unit coil; Coil connectors: Each sub-unit coil is provided with two coil connectors, and the coil connectors of two adjacent layers of sub-unit coils are staggered so that the current forms a spirally ascending conductive structure along the stacking direction; The stacking process includes: Leveling the support platform and marking characteristic lines on the support platform; The sub-unit coil is fixed with a plurality of first clamps along the circumferential direction, and the sub-unit coil is lifted and kept in horizontal movement by the lifting fixture and placed on the support platform; Measure the sub-unit coil contour and coil joint position. If they meet the preset requirements, proceed to the next step; if not, perform correction until the preset requirements are met. Replacing the plurality of first clamps outside the subunit coils with second clamps, and connecting the hanger to the second clamps; Using a hoist, the second fixture and the sub-unit coil are lifted by a preset distance, and the characteristic line on the sub-unit coil is compared with the characteristic line on the support platform. If there is a deviation, the sub-unit coil profile is adjusted using a conformal tool or the angle of the sub-unit coil is adjusted using a circumferential tool until the characteristic line of the sub-unit coil is aligned with the characteristic line of the support platform, and the coil is dropped to complete the stacking of the sub-unit coils. Repeat the above steps until all sub-unit coils are stacked.

2. The superconducting coil stacking process according to claim 1, characterized in that: The surface of the subunit coil is paved with at least one layer of glass fiber cloth.

3. The superconducting coil stacking process according to claim 1, characterized in that: The step of circumferentially adjusting the subunit coils includes: After the sub-unit coil is hoisted, the circumferential adjustment device provided on the support platform adjusts the column to abut against the main frame of the second fixture, and the circumferential rotation angle of the sub-unit coil is adjusted by controlling the extension length of the adjustment column.

4. The superconducting coil stacking process according to claim 1, characterized in that: After completing the hoisting of each layer of the sub-unit coils, removing the second clamp; The second clamp includes a clamp body clamped on the side and upper surface of the sub-unit coil, and a steel belt is arranged around the bottom of the clamp body, and the steel belt surrounds the lower surface of the sub-unit coil. When removing the second clamp, the steel belt is cut and pulled out.

5. The superconducting coil stacking process according to claim 4, characterized in that: After the second clamp is removed, the actual height of the superconducting coil is obtained using a measuring tool, and then glass cloth is laid. The subunit coil is pressed to a preset height using a pressing tool.

6. The superconducting coil stacking process according to claim 5, characterized in that: The steps of laying the glass cloth include: Clean the surface of the subunit coil and lay at least one layer of glass cloth until the thickness of the laid glass cloth is the same as the preset height requirement.

7. The superconducting coil stacking process according to claim 1, characterized in that: The step of adjusting the contour of the sub-unit coil by the conformal tool includes: The position where the contour of the sub-unit coil deviates is determined, and the quick clamp in the shape-keeping tool at the position is pressed so that the pressure block at the end of the quick clamp squeezes the side surface of the sub-unit coil to adjust the contour.

8. The superconducting coil stacking process according to claim 1, characterized in that: A plurality of guide tools are provided along the circumferential outer edge of the support platform, and the guide tools are used to limit the falling position of the sub-unit coil.

9. A tokamak device, characterized in that: The invention comprises the superconducting coil as claimed in claim 1.

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