A high-temperature superconducting coil winding method containing an inner joint and a superconducting hybrid magnet

Abstract

The present invention discloses a method for winding a high-temperature superconducting coil containing an inner joint and a superconducting hybrid magnet, belonging to the technical field of superconducting magnets. The method comprises providing a cylindrical skeleton with an insulating winding surface and correspondingly providing a clamping mechanism and a heating mechanism capable of performing heat welding on the ends of the strip. The clamping mechanism and the heating mechanism are used to complete the heat welding between the ends of two strips not covered with an insulation layer, thereby enabling multiple strips not covered with an insulation layer to be wound sequentially on the insulating winding surface of the cylindrical skeleton to obtain a high-temperature superconducting coil containing an inner joint. The coil winding method of the present invention has simple steps and convenient operation, can meet the needs of winding the same magnet coil with different strips, quickly obtains a superconducting hybrid coil containing an inner joint, fully ensures the structural reliability of the strip winding process, meets the needs of different applications and testing, and ensures the engineering current density and thermal stability of the superconducting hybrid coil, thus having good practical and economic value.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting magnets, and in particular relates to a method for winding a high-temperature superconducting coil containing an inner joint and a superconducting hybrid magnet. Background Art

[0002] High-temperature superconducting magnets have broad application prospects in the fields of electric power industry, magnetic levitation transportation, basic physics research, and medical research due to their high critical temperature, high upper critical magnetic field, excellent mechanical properties and current carrying capacity.

[0003] Typically, superconducting magnets consist of multiple superconducting coils, each typically wound with a superconducting tape coated with an insulating layer. To ensure high-temperature superconducting magnets have a good current-carrying capacity, the superconducting coils are typically wound with a single, highly uniform superconducting tape. However, whether it's the first-generation high-temperature superconducting tape based primarily on bismuth, the second-generation high-temperature superconducting tape based primarily on yttrium, or the newer high-temperature superconducting tape represented by magnesium diboride, producing a single superconducting tape with long lengths, high current-carrying uniformity, and structural integrity significantly increases the complexity and cost of the tape manufacturing process.

[0004] Furthermore, the practice of using a single long strip to wind superconducting coils does not allow for high utilization of the shorter strips, hindering the cost reduction of superconducting magnets and hindering their further application. Although the use of superconducting joint manufacturing processes to weld long, highly uniform strips can somewhat reduce the need for long strips in magnets, the joint resistance and mechanical strength will be affected by the weld material, and parameters such as the length of the joint area and the weld thickness will also limit the performance of the long strips.

[0005] Furthermore, due to the manufacturing process and material properties, the quench propagation rate of high-temperature superconducting tapes is slow. The presence of the insulating layer significantly reduces the heat transfer efficiency between the strips, resulting in poor thermal stability of the superconducting magnet. This also increases the outer diameter of the superconducting magnet and reduces the operating current density. When special operating conditions such as localized hot spots or localized quenching occur, the heat inside the magnet cannot be effectively transferred from the interior to the cooling medium, resulting in an increased temperature rise. In severe cases, the entire magnet can be quenched or even damaged. Summary of the Invention

[0006] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a method for winding a high-temperature superconducting coil containing an inner joint and a superconducting hybrid magnet, which can effectively realize the application of short strips in the magnet manufacturing process, reduce the impact of strip welding on the magnet performance, and ensure the reliability and stability of the magnet during use.

[0007] To achieve the above object, one aspect of the present invention provides a method for winding a high-temperature superconducting coil containing an inner connector, which comprises the following steps:

[0008] (1) Preparing a first strip and a second strip without an insulating layer, and a cylindrical skeleton with an insulating winding surface;

[0009] (2) fixing the head end of the first strip on the insulating winding surface of the cylindrical skeleton, and winding the first strip on the cylindrical skeleton until the first strip is about to be wound to the end;

[0010] (3) A clamping mechanism and a heating mechanism are provided corresponding to the end welding process of the two strips, and solder is prepared;

[0011] (4) Aligning the end of the first strip with the beginning of the second strip in the strip thickness direction, and placing the solder between the two strips to form a portion to be welded; thereafter, clamping the portion to be welded by a clamping mechanism, and assembling the clamping mechanism to a heating mechanism, and completing the heating welding of the ends of the two strips by the heating mechanism;

[0012] (5) Continue winding the end of the first tape and the second tape on the cylindrical skeleton until the second tape is wound to the end, completing the tape winding and obtaining a high-temperature superconducting coil containing an inner joint.

[0013] As a further improvement of the present invention, in process (1), the width of the first strip is the same as that of the second strip;

[0014] and / or

[0015] The first strip and the second strip have different thicknesses, different critical currents, different mechanical strengths and / or different bending radii.

[0016] As a further improvement of the present invention, in process (1), the cylindrical skeleton is made of a low-temperature resistant insulating material; or, the cylindrical skeleton is made of a stainless steel material and an insulating treatment is performed on its surface.

[0017] As a further improvement of the present invention, in process (2), a plurality of buckles are provided corresponding to the first strip coil formed after the first strip is wound; and / or, in process (5), after the winding of all strips is completed, a plurality of buckles are provided on the cylindrical skeleton corresponding to the mixed strip coil formed after the winding of all strips; and

[0018] The buckle is arranged along the radial direction of the cylindrical frame, one end of which is clamped on the inner wall surface of the cylindrical frame, and the other end passes over the corresponding coil formed by winding the outer circumference of the cylindrical frame and is clamped on the outermost strip of the coil.

[0019] As a further improvement of the present invention, in process (3), the solder is a low-temperature solder having a melting point between 70°C and 150°C.

[0020] As a further improvement of the present invention, in process (3), the clamping mechanism includes a first cover plate and a second cover plate, and the heating mechanism is a heating table that can be used to place the two cover plates;

[0021] The heating temperature of the heating table is 100°C~250°C; the width of the two cover plates is 4~5 times the width of the two strips, the thickness is 1.5~3 cm, and the length is 2~3 times the length of the strip area to be welded.

[0022] As a further improvement of the present invention, the clamping mechanism includes two metal clamping blocks arranged opposite to each other, a heating device arranged corresponding to the two metal clamping blocks, and a plurality of pressure members arranged on the heating device;

[0023] The heating device is formed with a receiving cavity having two ends passing through it, and the width of the receiving cavity corresponds to the width of the metal clamping block, so that the two stacked metal clamping blocks can be correspondingly embedded in the receiving cavity; and

[0024] One end of the pressure piece is arranged opposite to the top of the stacked metal clamps, and the other end thereof is movably connected to the heating device. The pressure piece can be adjusted to apply clamping force to the stacked metal clamps, so that the two strips clamped between the two metal clamps can be continuously applied with uniform force by several pressure pieces during the welding process.

[0025] As a further improvement of the present invention, in process (4), before forming the portion to be welded, a process of setting the solder on the welding surfaces of the two strips is also carried out:

[0026] The end of the first strip and the beginning of the second strip are placed on a heating mechanism with the surfaces to be welded facing upward, and the heating mechanism performs initial heating on the two strips; solder is placed on the two surfaces to be welded, and heating is stopped after the solder on the two surfaces to be welded is completely melted; after the solder on the surfaces of the two strips cools and solidifies, the surfaces to be welded on the two strips respectively covered with solder are aligned and stacked to form the parts to be welded.

[0027] As a further improvement of the present invention, in process (4), before the welding ends of the two strips are aligned, a deoxidation treatment is performed on the end faces of the two ends facing each other, and the deoxidation treatment process is completed using phosphoric acid.

[0028] Another aspect of the present invention provides a superconducting hybrid magnet containing an inner joint, which includes a frame and a plurality of high-temperature superconducting coils assembled on the frame; at least one of the plurality of high-temperature superconducting coils is wound using the method for winding a high-temperature superconducting coil containing an inner joint.

[0029] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0030] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0031] (1) The method for winding a high-temperature superconducting coil containing an inner joint of the present invention comprises providing a cylindrical skeleton with an insulating winding surface and correspondingly providing a clamping mechanism and a heating mechanism capable of performing heating and welding of the ends of the strip, and utilizing the clamping mechanism and the heating mechanism to complete heating and welding between the ends of two strips without insulation layer coating, thereby achieving winding of multiple strips without insulation layer coating on the insulating winding surface of the cylindrical skeleton in sequence to obtain a high-temperature superconducting coil containing an inner joint; utilizing the method of the present invention, the rational utilization of shorter strips can be effectively achieved, the utilization rate of the strips can be improved, the winding requirements of the magnet coil faced in special circumstances when the length of a certain strip is insufficient, and the performance stability of the strip after being wound into a magnet can be fully guaranteed.

[0032] (2) The method for winding a high-temperature superconducting coil containing an inner joint of the present invention effectively ensures the reliability of the magnet coil after the strip is wound by optimizing the material and setting form of the cylindrical skeleton and correspondingly designing the structural form of the clamping mechanism and the heating mechanism, simplifies the welding process between different strips, ensures the welding quality of the strips, and improves the flexibility and functional stability of the magnet coil winding.

[0033] (3) The superconducting hybrid magnet of the present invention comprises a frame and a plurality of high-temperature superconducting coils assembled on the frame, and the frame comprises at least one high-temperature superconducting coil wound by the high-temperature superconducting coil winding method of the present invention. The preferred design of the high-temperature superconducting coil makes the structure of the magnet compact and the performance stable, which can effectively improve the utilization rate of the strip and the economy of the superconducting magnet, and improve the engineering current density and thermal stability of the superconducting magnet, reduce the current carrying performance attenuation caused by strip damage, and fully ensure the comprehensive performance of the magnet.

[0034] (4) The method for winding a high-temperature superconducting coil containing an inner joint in the present invention has simple steps and convenient operation. It can meet the needs of winding the same magnet coil with different tapes, quickly obtain a superconducting hybrid coil containing an inner joint, fully ensure the structural reliability of the tape winding process, meet different application and testing requirements, ensure the engineering current density and thermal stability of the superconducting hybrid coil, and have good practical value and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 1 is a flow chart of a method for winding a high-temperature superconducting coil including an inner connector according to an embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of winding a first tape in a high-temperature superconducting coil winding method according to an embodiment of the present invention;

[0038] Figure 3 2 is a schematic diagram of the high-temperature superconducting coil winding method according to an embodiment of the present invention when the first tape is wound;

[0039] Figure 4 1 is a schematic structural diagram of a clamping mechanism and a heating mechanism for strip welding in one embodiment of the present invention;

[0040] Figure 5 、 Figure 6 is a schematic structural diagram of a clamping mechanism and a heating mechanism in another embodiment of the present invention;

[0041] Figure 7 3 is a schematic diagram of the coil structure when the second strip is wound in an embodiment of the present invention.

[0042] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0043] 1. First strip; 2. Second strip; 3. Cylindrical frame; 4. Buckle; 5. First cover; 6. Second cover; 7. Solder; 8. Heating table; 9. Metal clamp; 10. Heating device; 11. Pressurizing piece. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0045] In the description of the present invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0049] Example:

[0050] The high-temperature superconducting coil winding method in the preferred embodiment is mainly used for winding a high-temperature superconducting coil containing an inner joint, so as to obtain a high-temperature superconducting coil with a certain overcurrent capacity and self-protection capability.

[0051] like Figure 1As shown in , the method for winding a high-temperature superconducting coil containing an inner connector in a preferred embodiment of the present invention includes the following steps:

[0052] (1) Prepare the materials, namely, a first strip material 1 without an insulation layer, a second strip material 2, and a cylindrical skeleton 3 with an insulating winding surface;

[0053] Specifically, the preferred embodiment uses uninsulated first and second strips 1 and 2 because removing the insulating layer increases the magnet's engineering current density, making the magnet structure more compact. Furthermore, the wound strips directly contact each other through the metal layer, resulting in faster heat transfer and improved thermal stability. Furthermore, because excess current within the strips can be diverted to adjacent strips through the metal contact layer, the magnet possesses a certain level of overcurrent resistance and self-protection capabilities, resulting in even better performance.

[0054] Furthermore, the coil winding method in the preferred embodiment does not have strict requirements on the uniformity of the tape. It can use high-temperature or low-temperature superconducting tapes with different current-carrying properties, mechanical strength and manufacturing processes to make joints according to application requirements, and then wind superconducting hybrid coils.

[0055] In actual material preparation, the widths of the first tape 1 without an insulating layer and the second tape 2 are preferably kept consistent. At the same time, superconducting tapes with different thicknesses, different critical currents, and different mechanical strengths can be selected according to application requirements.

[0056] For example, in a specific preferred embodiment, the first tape 1 used for winding the inner coil is a superconducting tape with a small bending radius, while the second tape 2 used for winding the outer coil is a superconducting tape with a large bending radius.

[0057] In another specific preferred embodiment, the thickness of the second strip 2 is greater than the thickness of the first strip 1 .

[0058] In more detail, the cylindrical skeleton 3 in the preferred embodiment is preferably cylindrical, and the circumferential surface of the cylinder for winding the first strip 1 is an insulating surface.

[0059] Further preferably, the cylindrical skeleton 3 is made of a low-temperature resistant insulating material, such as epoxy resin, ceramic or aluminum nitride material; or, the cylindrical skeleton 3 is made of a stainless steel material and its surface is subjected to insulation treatment.

[0060] (2) Fixing the head end of the first strip 1 on the insulating winding surface of the cylindrical skeleton 3, and winding the first strip 1 on the cylindrical skeleton 3 until the first strip 1 is about to be wound to the end;

[0061] In actual configuration, a driving device, such as a reduction motor, is provided corresponding to the winding of the cylindrical skeleton 3 . The driving device is used to drive the cylindrical skeleton 3 to rotate, thereby completing the winding process of the first strip 1 .

[0062] In more detail, in the preferred embodiment, the running speed of the first strip 1 is 0.1 m / min.

[0063] Of course, it is understandable that, according to the requirements of the setting, the winding of the first strip 1 can also be completed by other means and equipment, such as setting a tape reel to carry out the winding of the first strip 1.

[0064] By winding the first strip 1 on the cylindrical frame 3, a wound first coil can be formed on the outer periphery of the cylindrical frame 3, such as Figure 2 As shown in .

[0065] More preferably, after the winding of the first strip 1 is completed, the corresponding first coil is also provided with a plurality of clips 4, which are preferably arranged along the radial direction of the cylindrical skeleton 3, with one end clipped onto the inner wall surface of the cylindrical skeleton 3, and the other end passing over the first coil on the outer periphery of the cylindrical skeleton 3 and clipped onto the outermost strip of the first coil.

[0066] For example, in Figure 3 In the preferred embodiment shown in , the number of buckles 4 provided is 8, which are arranged at intervals in the circumferential direction. The buckles 4 are further preferably arranged at equal intervals in the circumferential direction, thereby ensuring the reliability of the winding state of each area position in the circumferential direction of the first coil.

[0067] Further preferably, during actual winding, the unwound end length of the first strip 1 is preferably not less than 50 mm, so as to facilitate subsequent strip processing steps and thereby meet the requirements of subsequent strip welding.

[0068] (3) A clamping mechanism and a heating mechanism are provided corresponding to the end welding process of the two strips, and solder 7 is prepared;

[0069] In a preferred embodiment, solder 7 is preferably a low-temperature solder with a melting point between 70°C and 150°C, such as Wood's metal with a melting point of 100°C. Low-temperature solder is chosen because its low melting point minimizes the current-carrying performance of the superconducting tape during heat treatment. Furthermore, low-temperature solder residue is minimal, preventing excessive joint resistance from being caused by excessive solder thickness in the joint area.

[0070] During the actual welding operation, the amount of solder 7 used should be enough to completely cover the surface of one side of the two strips without dripping. If there is excessive solder, it is preferred to use a scraper to scrape the excess solder 7 to the edges of the two strips, and then use a solder sucker to absorb the excess solder 7.

[0071] Furthermore, the clamping mechanism in the preferred embodiment is used to clamp and fix the ends of the two strips with the solder 7 provided between their end faces, ensuring that the two strip ends and the solder 7 can remain in alignment after the end alignment is completed.

[0072] Correspondingly, the heating mechanism is provided corresponding to the clamping mechanism, and is used to heat the two strips to be welded, thereby melting the solder 7 between the two strips, thereby completing the welding of the two strips.

[0073] In a specific preferred embodiment, the clamping mechanism is preferably as follows Figure 4 The two cover plates shown in the figure are the first cover plate 5 and the second cover plate 6; accordingly, the heating mechanism is a heating table 8 provided corresponding to the two cover plates, and the heating temperature is preferably 100°C to 250°C.

[0074] During the final welding, the first cover plate 5 is set on the heating table 8. Through the combination of the heating table 8 and the two cover plates, after the two cover plates complete the clamping setting of the two strips, the heating table 8 can heat and increase the temperature accordingly, thereby realizing the melting of the solder 7 and the welding of the ends of the two strips.

[0075] More preferably, the two cover plates are preferably copper cover plates, which have high thermal conductivity and can fully utilize the heat released by the heating platform 8 to accurately complete the melting and welding process of the solder 7 and ensure the welding quality of the low-temperature solder.

[0076] In actual use, the time for heating and welding using the heating stage 8 is preferably 30s to 90s.

[0077] Further preferably, the two cover plates are of the same size and preferably have a rectangular plate structure, with a width of 4 to 5 times the width of the strip, a thickness of 1.5 to 3 cm, and a length of 2 to 3 times the length of the strip area to be welded.

[0078] In another specific preferred embodiment, the clamping mechanism and the heating mechanism are combined to form a hot pressing mechanism, which is arranged in the form of Figure 5 、 Figure 6 As shown in , it includes two metal clamping blocks 9 arranged opposite to each other, a heating device 10 arranged corresponding to the two metal clamping blocks 9, and a plurality of pressurizing members 11 arranged on the heating device 10.

[0079] Specifically, the heating device 10 in this embodiment has a cavitation cavity extending through both ends, into which the strip to be heated can be inserted and placed. In practice, the width of the cavity preferably corresponds to the width of the metal clamps 9, so that the two stacked metal clamps 9 can fit into the cavities. Furthermore, a pressure member 11 has one end positioned directly opposite the tops of the stacked metal clamps 9, while its other end is movably connected to the heating device 10. Adjustment of the pressure member 11 allows it to apply a clamping force to the stacked metal clamps 9.

[0080] Correspondingly, the first strip 1 and the second strip 2 with overlapping ends and solder 7 provided therebetween can be placed just between the two metal clamps 9, and during the welding process of the two strips, a plurality of pressure members 11 continuously apply a uniform force to the two strips to ensure the uniformity of the distribution of the welding material between the two strips and improve the welding effect of the strips.

[0081] During actual operation, the pressure member 11 uniformly applies a force of 1 MPa to 10 MPa.

[0082] After the strips are heated and welded, a cooling mechanism, such as a hair dryer, may be further preferably provided. The cooling mechanism can be used to achieve rapid cooling of the clamping mechanism and the welding portion of the two strips.

[0083] (4) Align the end of the first strip 1 and the beginning of the second strip 2 in the strip thickness direction, and place solder 7 between the two strips to form a portion to be welded; thereafter, the portion to be welded is clamped by a clamping mechanism, and the clamping mechanism is assembled to a heating mechanism, and the heating mechanism completes the heating welding of the ends of the two strips;

[0084] Furthermore, in actual operation, it is preferred that before forming the portion to be welded, a process of setting the solder 7 on the welding surfaces of the two strips is also performed:

[0085] The end of the first strip 1 and the beginning of the second strip 2 are placed on a heating mechanism with the surfaces to be welded facing upward, and the heating mechanism performs initial heating on the two strips; solder 7 is placed on the two surfaces to be welded, and heating is stopped after the solder on the two surfaces to be welded is completely melted; after the solder on the surfaces of the two strips cools and solidifies, the surfaces to be welded on the two strips, respectively covered with solder 7, are aligned and stacked to form the parts to be welded.

[0086] It is understood that after the solder 7 is applied to the two surfaces to be welded, the excess solder 7 can be scraped off to ensure accuracy in the subsequent alignment of the two strips. Furthermore, after the secondary heating and welding of the two strips after alignment, the excess solder 7 can be scraped off to ensure the cleanliness of the welded area.

[0087] Furthermore, during actual welding, before the two strip ends are stacked, the ends facing each other are preferably subjected to a deoxidation treatment, and it is further preferred to remove the oxide layer on the end surfaces of the strips to be welded by using an appropriate amount of phosphoric acid.

[0088] More preferably, the lengths of the first strip 1 and the second strip 2 subjected to the oxidation layer removal treatment are preferably the same.

[0089] (5) Continue winding the end of the first strip 1 and the second strip 2 on the cylindrical skeleton 3 until the second strip 2 is wound to the end, completing the winding of a single single-piece coil and obtaining a high-temperature superconducting coil with an inner joint.

[0090] In actual operation, after the winding of the second strip 2 is completed, the third, fourth, ... Nth strips (N is greater than 2) can be wound as needed, thereby obtaining a single-piece coil containing multiple (more than 2) sections of strips.

[0091] In addition, after all the strips are wound, it is further preferred to set a number of buckles 4 on the cylindrical frame 3 corresponding to the wound coils, such as Figure 7 As shown in , this ensures the stability of the coils formed after each strip is wound.

[0092] The aforementioned method for winding a high-temperature superconducting coil with an inner joint allows for combining superconducting tapes of varying current carrying capacities and mechanical strengths, meeting requirements such as high-field critical current testing, optimal thermal stability design, and optimal structural stability design. Furthermore, the aforementioned method is particularly suitable for testing new tapes. Because the production volume of new tapes may be extremely low, it is difficult to wind a complete coil, making it difficult to test the current carrying capacity and mechanical properties of coils wound with new superconducting tapes. In such cases, the method of the preferred embodiment allows for the winding of a mixture of new tapes and other types of tapes, thereby completing the testing process.

[0093] As another aspect of the present invention, a superconducting hybrid magnet containing an inner joint is provided, which includes a frame and a plurality of high-temperature superconducting coils assembled on the frame; and at least one of the plurality of high-temperature superconducting coils is wound using the aforementioned method for winding a high-temperature superconducting coil containing an inner joint.

[0094] The method in the preferred embodiment is described in detail below through a specific embodiment, which relates to an yttrium barium copper oxide (YBCO)-iron selenium tellurium (FeSeTe) hybrid magnet and a winding method thereof, comprising the following steps:

[0095] (1) Prepare a FeSeTe strip without an insulating layer, a YBCO strip without an insulating layer, and an insulating skeleton made of epoxy resin;

[0096] Specifically, the FeSeTe strip has a length of 0.5 m, a width of 5 mm, and a thickness of 0.15 mm; the YBCO strip has a length of 2.5 m, a width of 5 mm, and a thickness of 0.1 mm.

[0097] Correspondingly, the length of the insulating frame is 10 mm, the inner diameter is 25 mm, and the outer diameter is 30 mm, that is, the wall thickness of the insulating frame is 5 mm.

[0098] (2) Fix the head end of the FeSeTe strip on the outer wall of the insulating frame, and assemble the insulating frame on the rotating output shaft of the reduction motor. Control the FeSeTe strip to be wound at a speed of 0.1 m / min until the FeSeTe strip is wound to the tail end;

[0099] Afterwards, the power supply of the reduction motor is turned off, and a number of clips are used to fix the coil wound by the FeSeTe strip around the outer periphery of the insulation frame.

[0100] (3) Prepare two copper plates as the clamping mechanism for welding the two strips, and set up heating tables corresponding to the two copper plates;

[0101] In actual operation, the two copper plates have the same size, 50 mm in width, 150 mm in length, and 10 mm in thickness.

[0102] (4) Use a small amount of phosphoric acid to remove the surface oxide layer on the end of the FeSeTe strip and the beginning of the YBCO strip, and remove the oxide layer on the end surface of the two strips to be welded; in actual operation, the length of the end surface of the two strips where the oxide layer is removed is 40 mm;

[0103] The surface-treated FeSeTe strip and YBCO strip are placed on the heating table 8 respectively, with the end faces after the oxidation layer treatment facing upwards. Then, a small amount of low-temperature solder is placed on both end faces. The heating table 8 is used to heat each strip until the low-temperature solder is completely melted. After that, the heating of the heating table 8 is stopped, so that the melted low-temperature solder solidifies and is evenly coated on the end faces to be welded of the two strips.

[0104] Next, the first copper plate, the end of the FeSeTe strip coated with low-temperature solder, the beginning of the YBCO strip coated with low-temperature solder, and the second copper plate are stacked on heating table 8 in this order, with the ends of the strips, the oxide layers removed, aligned and held between the two copper plates. Heating table 8 is then controlled to perform a secondary heating of the two strips stacked between the two copper plates, completing the end welding of the two strips. Heating table 8 is then deactivated, and the welded portion of the two strips is allowed to cool, completing the end welding of the two strips.

[0105] After welding is completed, it is further preferred to scrape off the welding material that overflows from the welding portion of the two strips.

[0106] In this embodiment, the model of low-temperature solder selected is preferably HT100 Wood's alloy, which has a melting point of 100°C; the working temperature of the heating table 8 is controlled to 125°C, the initial heating time is 30s, the secondary heating time is 40s, and the cooling time after welding is completed is preferably 10min.

[0107] (5) Remove the clips on the insulating frame used to fix the 6 wound coils, and continue to wind the YBCO tape until its end, to obtain a high-temperature superconducting coil made of two tapes and with an internal joint, thereby meeting the testing requirements of FeSeTe tape or YBCO tape.

[0108] The method for winding a high-temperature superconducting coil containing an inner joint in the present invention has simple steps and convenient operation. It can meet the needs of winding the same magnet coil with different tapes, quickly obtain a superconducting hybrid coil containing an inner joint, fully ensure the structural reliability of the tape winding process, meet different application and testing requirements, ensure the engineering current density and thermal stability of the superconducting hybrid coil, and has good practical and economic value.

[0109] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 method for winding a high-temperature superconducting coil containing an inner connector, characterized in that: The process includes the following: (1) Preparing a first strip and a second strip without an insulating layer, and a cylindrical skeleton with an insulating winding surface; (2) fixing the head end of the first strip on the insulating winding surface of the cylindrical skeleton, and winding the first strip on the cylindrical skeleton until the first strip is about to be wound to the end; (3) A clamping mechanism and a heating mechanism are provided corresponding to the end welding process of the two strips, and solder is prepared; (4) Aligning the end of the first strip with the beginning of the second strip in the strip thickness direction, and placing the solder between the two strips to form a portion to be welded; thereafter, clamping the portion to be welded by a clamping mechanism, and assembling the clamping mechanism to a heating mechanism, and completing the heating welding of the ends of the two strips by the heating mechanism; (5) Continue winding the end of the first tape and the second tape on the cylindrical skeleton until the second tape is wound to the end, completing the tape winding and obtaining a high-temperature superconducting coil containing an inner joint.

2. The method for winding a high-temperature superconducting coil containing an inner connector according to claim 1, characterized in that: In process (1), the first strip and the second strip have the same width; and / or The first strip and the second strip have different thicknesses, different critical currents, different mechanical strengths and / or different bending radii.

3. The method for winding a high-temperature superconducting coil containing an inner connector according to claim 1, characterized in that: In process (1), the cylindrical frame is made of low-temperature resistant insulating material; or, the cylindrical frame is made of stainless steel and its surface is subjected to insulation treatment.

4. The method for winding a high-temperature superconducting coil containing an inner connector according to any one of claims 1 to 3, characterized in that: In process (2), a plurality of buckles are provided on the first strip coil formed after the first strip is wound; and / or, in process (5), after the winding of all strips is completed, a plurality of buckles are provided on the cylindrical skeleton corresponding to the mixed strip coil formed after the winding of all strips; and The buckle is arranged along the radial direction of the cylindrical frame, one end of which is clamped on the inner wall surface of the cylindrical frame, and the other end passes over the corresponding coil formed by winding the outer circumference of the cylindrical frame and is clamped on the outermost strip of the coil.

5. The method for winding a high-temperature superconducting coil containing an inner connector according to any one of claims 1 to 3, characterized in that: In process (3), the solder is a low-temperature solder having a melting point between 70°C and 150°C.

6. The method for winding a high-temperature superconducting coil containing an inner connector according to claim 5, characterized in that: In process (3), the clamping mechanism includes a first cover plate and a second cover plate, and the heating mechanism is a heating table that can be used to place the two cover plates; The heating temperature of the heating table is 100°C~250°C; the width of the two cover plates is 4~5 times the width of the two strips, the thickness is 1.5~3 cm, and the length is 2~3 times the length of the strip area to be welded.

7. The method for winding a high-temperature superconducting coil containing an inner connector according to claim 5, characterized in that: The clamping mechanism includes two metal clamping blocks arranged opposite to each other, a heating device arranged corresponding to the two metal clamping blocks, and a plurality of pressure members arranged on the heating device; The heating device is formed with a receiving cavity having two ends passing through it, and the width of the receiving cavity corresponds to the width of the metal clamping block, so that the two stacked metal clamping blocks can be correspondingly embedded in the receiving cavity; and One end of the pressure piece is arranged opposite to the top of the stacked metal clamps, and the other end thereof is movably connected to the heating device. The pressure piece can be adjusted to apply clamping force to the stacked metal clamps, so that the two strips clamped between the two metal clamps can be continuously applied with uniform force by several pressure pieces during the welding process.

8. The method for winding a high-temperature superconducting coil containing an inner connector according to any one of claims 1 to 3, 6, and 7, characterized in that: In process (4), before forming the portion to be welded, a process of setting the solder on the welding surfaces of the two strips is also carried out: The end of the first strip and the beginning of the second strip are placed on a heating mechanism with the surfaces to be welded facing upward, and the heating mechanism performs initial heating on the two strips; solder is placed on the two surfaces to be welded, and heating is stopped after the solder on the two surfaces to be welded is completely melted; after the solder on the surfaces of the two strips cools and solidifies, the surfaces to be welded on the two strips respectively covered with solder are aligned and stacked to form the parts to be welded.

9. The method for winding a high-temperature superconducting coil containing an inner connector according to claim 8, characterized in that: In process (4), before the welding ends of the two strips are aligned, the two surfaces to be welded are subjected to a deoxidation treatment, wherein the deoxidation treatment is performed using phosphoric acid.

10. A superconducting hybrid magnet with an inner joint, comprising a frame and a plurality of high-temperature superconducting coils assembled on the frame; characterized in that: At least one of the plurality of high-temperature superconducting coils is wound using the method for winding a high-temperature superconducting coil containing an inner joint according to any one of claims 1 to 9.

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