Superconducting conductor winding method and superconducting conductor

Abstract

The embodiment of the present application provides a superconducting conductor winding method and a superconducting conductor, wherein the superconducting conductor winding method comprises: inserting a superconducting stacked tape into a superconducting stacked tape slot of a conductor skeleton; after the superconducting stacked tape is inserted, twisting the conductor skeleton to obtain a twisted conductor skeleton; inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable, wherein the conductor skeleton shell includes at least one cooling channel; winding and curing the superconducting cable to obtain a superconducting conductor. By twisting the conductor skeleton after the superconducting stacked tape is inserted, the conductor space utilization rate is higher, and the engineering current density of the superconducting conductor is further improved. In addition, placing the cooling channel in the conductor skeleton shell improves the overall cooling effect of the superconducting conductor, and at the same time, it can also improve the overall current density of the superconducting conductor and reduce the flow resistance.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of high-temperature superconducting technology, and in particular to a superconducting conductor winding method and a superconducting conductor. Background Art

[0002] High-temperature superconducting tapes have high upper critical magnetic field strength, large critical current density and good mechanical properties. In addition, due to the limitation of the upper critical magnetic field of low-temperature superconducting tapes, the development of high-temperature superconductivity has attracted much attention. When winding large high-temperature superconducting coils, in order to reduce the coil inductance and increase the coil stability, high-temperature superconducting tapes are usually stacked and welded in parallel to form superconducting stacked cables. The stacking method of superconducting stacks is mainly the stacking welding method along the tangent direction of the high-temperature superconducting skeleton. The high-temperature superconducting cable manufactured in this way will generate a larger self-field as the number of layers of stacked high-temperature superconducting tapes increases. The existence of the self-field seriously affects the current carrying capacity and current density of the high-temperature superconductor, and will seriously affect the magnetic field distribution inside the cable and the safe and stable operation of the cable.

[0003] In a tokamak fusion device, the current change rate of the central solenoid (CS) magnet reaches tens of kiloamperes per second. In order to reduce the AC loss of the high-temperature superconducting CS magnet, a high-temperature superconducting cable with a transposition structure can be used. At present, an internal hollow channel can usually be constructed in the circular core skeleton, and a cooling medium flows through the internal hollow channel to evenly cool the magnet. However, if a small-aperture hollow channel is used, the cable flow resistance is too large, and the cooling medium can only be expensive superfluids; if the aperture of the hollow channel is increased, the strain of the external superconducting tape will increase when twisting and bending, reducing the bending radius of the cable. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a superconducting conductor winding method. One or more embodiments of the present application also relate to a superconducting conductor to solve the technical defects existing in the prior art.

[0005] According to a first aspect of an embodiment of the present application, a superconducting conductor winding method is provided, comprising: inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton; After the superconducting stacked tape is inserted, the conductor skeleton is twisted to obtain a twisted conductor skeleton; Inserting the twisted conductor skeleton into a skeleton channel of a conductor skeleton shell to obtain a superconducting cable, wherein the conductor skeleton shell includes at least one cooling channel; The superconducting cable is wound and solidified to obtain a superconducting conductor.

[0006] According to a second aspect of an embodiment of the present application, a superconducting conductor is provided, comprising a conductor skeleton and a conductor skeleton shell, wherein the conductor skeleton comprises a plurality of superconducting stacked tape slots, wherein superconducting stacked tapes are inserted into the plurality of superconducting stacked tape slots, and the conductor skeleton shell comprises a skeleton channel and at least one cooling channel, wherein the skeleton channel is used to insert a twisted conductor skeleton, and the cooling channel is used to fill cooling material, and the cooling material is used to cool the superconducting conductor.

[0007] A superconducting conductor winding method provided by an embodiment of the present application includes: inserting a superconducting stacked tape into a superconducting stacked tape slot of a conductor skeleton; after the superconducting stacked tape is inserted, twisting the conductor skeleton to obtain a twisted conductor skeleton; inserting the twisted conductor skeleton into a skeleton channel of a conductor skeleton shell to obtain a superconducting cable, wherein the conductor skeleton shell includes at least one cooling channel; winding and curing the superconducting cable to obtain a superconducting conductor. By twisting the conductor skeleton after the superconducting stacked tape is inserted, the conductor space utilization rate is higher, and the engineering current density of the superconducting conductor is further improved. In addition, placing the cooling channel in the conductor skeleton shell improves the overall cooling effect of the superconducting conductor, and at the same time, it can also improve the overall current density of the superconducting conductor and reduce the flow resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a flow chart of a superconducting conductor winding method provided by one embodiment of the present application; Figure 2 is a schematic cross-sectional view of a conductor skeleton provided by an embodiment of the present application; Figure 3 This is a schematic diagram of the structure of a conductor skeleton provided by an embodiment of the present application; Figure 4 It is a schematic diagram of the structure of a superconducting stacked tape provided by an embodiment of the present application; Figure 5 is a schematic diagram of a torsion pitch simulation result provided by an embodiment of the present application; Figure 6 This is a schematic diagram of the structure of a conductor skeleton housing provided by an embodiment of the present application; Figure 7 This is a schematic diagram of a simulation result of cold helium air flow resistance provided by an embodiment of the present application; Figure 8 is a schematic diagram of a superconducting cable provided by an embodiment of the present application; Fig. 9 This is a schematic diagram of a bending radius simulation result provided by an embodiment of the present application; Fig.10 is a schematic structural diagram of a superconducting conductor provided by an embodiment of the present application; Fig.11This is a schematic diagram of a conductor critical current simulation result provided by an embodiment of the present application. DETAILED DESCRIPTION

[0009] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0010] The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "one", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items. The term "at least one" in one or more embodiments of the present application refers to "one or more", and "multiple" refers to "two or more". The term "including" is an open description and should be understood as "including but not limited to", and may include other content on the basis of the content described.

[0011] It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0012] First, the terms involved in one or more embodiments of the present application are explained.

[0013] Tokamak: When electricity is supplied, a huge spiral magnetic field is generated inside the Tokamak, heating the plasma inside to a very high temperature to achieve the purpose of nuclear fusion.

[0014] Central solenoid: It is a key component in the tokamak device, mainly used to generate a strong magnetic field, which is essential for driving plasma current and maintaining plasma stability.

[0015] REBCO (Rare Earth Barium Copper Oxide) superconducting tape: is a high-temperature superconducting material based on rare earth barium copper oxide. The rare earth elements (RE, Rare Earth) here usually include yttrium (Y), gadolinium (Gd), samarium (Sm), europium (Eu), etc., among which yttrium is the most common, so REBCO sometimes specifically refers to yttrium barium copper oxide. REBCO superconducting tape has high-temperature superconductivity, high critical current density and good mechanical properties, and is suitable for various industrial applications.

[0016] Lay Length or Pitch of Twist (LP) is a physical quantity that measures the degree of twist, indicating the distance required to complete a full twist on a given length of material. For example, if a conductor skeleton rotates one circle (360 degrees) every time it advances 1 meter in the housing, then the twist pitch of the conductor skeleton is 1 meter.

[0017] Torsional Strain: refers to the degree of deformation produced inside an object, such as a wire, cable or structural member, when a torsional force is applied to it. Torsional strain is an important parameter for measuring how a material deforms under torque, and is crucial for evaluating the mechanical properties of materials and designing structures that can withstand specific loads.

[0018] Superconducting conductor: also known as superconducting material, refers to a superconductor that has two independent characteristics below a certain temperature, namely, absolute zero resistance and complete anti-magnetism. After a superconducting conductor fully enters the superconducting state, it will completely expel the external magnetic field from the body, that is, the equivalent anti-magnetic volume reaches a maximum of 100%, and the anti-magnetic susceptibility is -1.

[0019] In the present application, a superconducting conductor winding method is provided. The present application also relates to a superconducting conductor, which will be described in detail one by one in the following embodiments.

[0020] See also Figure 1 , Figure 1 A flow chart of a superconducting conductor winding method provided by an embodiment of the present application is shown, which specifically includes the following steps: Step 102: inserting the superconducting stacking tape into the superconducting stacking tape slot of the conductor skeleton.

[0021] It should be noted that the superconducting stacked tape refers to a composite structure consisting of multiple layers of superconducting tapes stacked. The superconducting stacked tape can be a square stacked tape. The superconducting stacked tape has high strength, good superconducting properties and adaptability to work in a strong magnetic field. Multiple layers of superconducting tapes are stacked together in the form of a "stack" to enhance the overall current carrying capacity of the superconducting stacked tape. The superconducting stacked tape can be a high-temperature superconducting material (such as REBCO superconducting tape).

[0022] The conductor skeleton refers to the basic structure used to support and fix the superconducting stacked strips. The conductor skeleton is usually made of non-magnetic materials (such as aluminum alloy, copper, etc.) to avoid interaction with the magnetic field generated by the superconductor. Preferably, since aluminum alloy has the advantage of low melting point, it can be continuously produced by extrusion process, and the electrical resistance of aluminum is slightly higher than that of copper, and the eddy current loss inside the conductor is lower. Therefore, the conductor skeleton is preferably made of aluminum alloy.

[0023] The superconducting stacking tape slot refers to a specially designed groove or channel on the conductor skeleton to accommodate and fix the superconducting stacking tape. The design of the superconducting stacking tape slot takes into account the size, shape and thermal expansion of the superconducting stacking tape after installation. By accurately placing the superconducting stacking tape in the superconducting stacking tape slot, it can ensure uniform current distribution, reduce energy loss, and improve the efficiency and stability of the entire superconducting magnet.

[0024] See also Figure 2 , Figure 2 A schematic cross-sectional view of a conductor skeleton provided in an embodiment of the present application is shown. The number of superconducting stacked tape slots included in the conductor skeleton can be three, four, five, six, etc., which is selected according to actual conditions, and the embodiment of the present application does not impose any limitation on this.

[0025] In one embodiment of the present application, the conductor skeleton further includes a quench detection channel; and before the above-mentioned winding and curing of the superconducting cable to obtain the superconducting conductor, the following steps may also be included: inserting an optical fiber in a quench detection channel; Winding and curing the superconducting cable to obtain a superconducting conductor may include the following steps: The superconducting cable inserted into the optical fiber is wound and solidified to obtain a superconducting conductor.

[0026] It should be noted that quench refers to the process in which a superconducting tape changes from its superconducting state to a normal resistance state. This process usually causes a large amount of energy to be released in the form of heat. If it cannot be detected and handled in time, it may cause damage to the equipment. Therefore, a quench detection channel can be set in the conductor skeleton. The quench detection channel refers to a path used to monitor whether a superconducting conductor has quenched. The quench detection channel can be the central aperture of the conductor skeleton. Optical fiber is a slender, flexible medium used for optical signal transmission, usually made of glass or plastic. Due to its excellent temperature sensing ability, anti-electromagnetic interference characteristics, long-distance monitoring capability and flexible installation method, optical fiber can be used as a quench detection tool.

[0027] By applying the solution of the embodiment of the present application and inserting an optical fiber into the quench detection channel, the excellent performance of the optical fiber can be utilized to achieve high-precision and rapid monitoring of the state of the superconducting conductor, thereby improving the safety and reliability of the entire superconducting conductor.

[0028] See also Figure 3 , Figure 3 A schematic structural diagram of a conductor skeleton provided in one embodiment of the present application is shown, wherein the conductor skeleton includes five identical superconducting stacked tape slots and a quench detection channel.

[0029] In one embodiment of the present application, before inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton, the superconducting stacked tape can be manufactured. That is, before inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton, the following steps can also be included: A plurality of superconducting tapes are stacked, and metal tapes are covered above and below the stack of the plurality of stacked superconducting tapes to obtain a superconducting stacked tape.

[0030] It should be noted that the metal tape can protect the stacked superconducting tape from being damaged when inserted into the superconducting stacking tape slot. Above the stack and below the stack refer to the positions where the multiple superconducting tapes after stacking are in contact with the superconducting stacking tape slot. The metal tape can be a variety of materials such as a thin copper tape, a thin stainless steel tape, a thin aluminum tape, a thin solder tape, etc., and is selected according to actual conditions. The embodiments of the present application do not impose any restrictions on this. If the thickness of the metal tape is too thick, the overall current density of the superconducting conductor will be reduced. If the thickness of the metal tape is too thin, the purpose of protecting the superconducting tape cannot be achieved. Therefore, two layers of thin metal tapes of the same thickness and width as the superconducting tape can be covered above and below the stack of the multiple superconducting tapes after stacking.

[0031] By applying the solution of the embodiment of the present application, metal tapes are covered above and below the stack of multiple superconducting tapes after stacking, thereby protecting the stacked superconducting tapes from damage when inserted into the superconducting stacking tape slots, making the superconducting conductor more stable.

[0032] In one embodiment of the present application, in addition to using a metal tape to protect the superconducting tape from being damaged, a solder wire may be used to fix the superconducting stacked tapes so as not to spread out. That is, before inserting the superconducting stacked tapes into the superconducting stacked tape slots of the conductor frame, the following steps may be included: Winding a solder wire around the outside of the superconducting stacked tape to obtain a fixed superconducting stacked tape; Inserting the superconducting stacking tape into the superconducting stacking tape slot of the conductor skeleton may include the following steps: The fixed superconducting stacking tapes are inserted into the superconducting stacking tape slots of the conductor skeleton.

[0033] It should be noted that solder wire is a metal alloy wire used for electronic welding, usually composed of tin and other metals (such as lead, silver, copper or bismuth). Since the conductor skeleton is subsequently immersed in liquid solder, the solder wire can be used here to fix the superconducting stacked strips, and the solder wire will also melt into the liquid solder.

[0034] By applying the solution of the embodiment of the present application, the solder wire is tightly wound on the outside of the superconducting stacked tape, which can ensure that the superconducting stacked tape is not easily scattered during the twisting process, and can also ensure that sufficient solder is provided for the superconducting stacked tape during the subsequent solder dipping process.

[0035] See also Figure 4 , Figure 4 A schematic structural diagram of a superconducting stacked tape provided by an embodiment of the present application is shown. Taking any one of the five square superconducting stacked tapes as an example, the middle of the superconducting stacked tape is 30 layers of 3 mm wide superconducting tapes, and the stack of 30 layers of 3 mm wide superconducting tapes is covered with two layers of thin copper tapes above and below, respectively, and multiple layers of solder wire are tightly wound on the outside of the superconducting stacked tape.

[0036] Step 104: After the superconducting stacked tape is inserted, the conductor skeleton is twisted to obtain a twisted conductor skeleton.

[0037] It should be noted that the conductor skeleton itself is straight. The superconducting stacked tapes are inserted into the superconducting stacked tape slots of the conductor skeleton. After the superconducting tape stacked tapes are placed in place, the conductor skeleton with the inserted superconducting stacked tapes is twisted as a whole. After the twisting, the superconducting tape stacked tapes are tilted as a whole. The tilted superconducting tape stacked tapes not only make the overall structure of the superconducting cable more compact, but also can cooperate with the sliding trend inside the tape in the subsequent preparation process of the superconducting conductor, which is safer.

[0038] The smaller the torsion pitch of the superconducting conductor, the lower the AC loss. However, torsion will cause torsional strain and damage the strip. Therefore, the torsion pitch cannot be too small. In the embodiment of the present application, in order to determine the minimum torsion pitch of the conductor skeleton, the conductor is simulated and calculated. The calculation results are shown in Figure 5 See Figure 5 , Figure 5 A schematic diagram of a torsion pitch simulation result provided by an embodiment of the present application is shown. Figure 5 The model on the left is to solder and dip the superconducting stacked tape into a whole, and then put it into the conductor frame. The simulation determines that when the torsion pitch is 2.2m, it is close to the critical stress of the superconducting stacked tape of 700MPa; Figure 5The model on the right is that the superconducting stacked tapes are not solder-impregnated as a whole. There is slippage between the superconducting stacked tapes. Each superconducting stacked tape is not constrained by the adjacent superconducting stacked tapes, and its torsion pitch can reach 0.3m. Therefore, in order to reduce the AC loss of the superconducting conductor and achieve a smaller torsion pitch, the superconducting stacked tapes can be kept slippable, and then the conductor skeleton is placed in the conductor skeleton for twisting before being impregnated. At the same time, in order to further protect the superconducting stacked tapes, in practical applications, the torsion pitch of the superconducting stacked tapes can be fixed at 0.5m.

[0039] Step 106: inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable, wherein the conductor skeleton shell includes at least one cooling channel.

[0040] It should be noted that the conductor skeleton shell refers to an outer protective layer or structure surrounding the conductor skeleton, which is intended to provide additional mechanical protection and support. The conductor skeleton shell can be square or circular. The conductor skeleton shell contains at least one cooling channel, which is used to conduct cooling materials (also referred to as cooling media) to provide a source of cold for the superconducting cable, thereby maintaining the operating temperature of the superconducting conductor. The cooling material includes but is not limited to liquid nitrogen, liquid helium, cold helium, etc., which are selected according to actual conditions, and the embodiments of the present application do not impose any restrictions on this. The skeleton channel refers to a specific channel in the conductor skeleton shell, which is used to accommodate and fix the twisted conductor skeleton to ensure its correct position and function. When the twisted conductor skeleton is inserted into the skeleton channel of the conductor skeleton shell, the formed assembly is called a superconducting cable. By removing the cooling channel from the conductor skeleton and placing it in the conductor skeleton shell, the overall current density of the superconducting cable can be improved.

[0041] See also Figure 6 , Figure 6 The schematic diagram of the structure of a conductor skeleton housing provided by an embodiment of the present application is shown. The conductor skeleton housing is a square housing, including a circular skeleton channel for placing the conductor skeleton. The conductor skeleton housing also includes a main cooling channel and two auxiliary cooling channels. The auxiliary cooling channels are used to assist the main cooling channel in cooling the superconducting stacked strips on the central conductor skeleton, so as to achieve a low temperature environment for normal flow of superconducting cables.

[0042] In one embodiment of the present application, the conductor skeleton shell may include only one main cooling channel, or may include only four auxiliary cooling channels located at the four corners of the conductor skeleton shell. The position and number of the cooling channels in the conductor skeleton shell are selected according to actual conditions, and the embodiment of the present application does not impose any limitations on this.

[0043] See also Figure 7 , Figure 7A schematic diagram of a cold helium air flow resistance simulation result provided by an embodiment of the present application is shown. Figure 7 From simulation calculations, it can be found that under the conditions of 20K and 5bar, a cold helium flow rate of 1g / s can meet the needs of tens of meters long superconducting cables, where K represents Kelvin and 5bar is equal to 500000 Pascal (Pa).

[0044] See also Figure 8 , Figure 8 FIG. 1 shows a schematic diagram of a superconducting cable provided by an embodiment of the present application. The twisted conductor skeleton (including superconducting stacked tapes) is placed in a conductor skeleton housing to form a superconducting cable. Figure 8 The cross-sectional utilization rate of the superconducting cable (superconducting stacked tape cross-sectional area / total superconducting cable cross-sectional area) can reach 21.4%.

[0045] In one embodiment of the present application, before inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton housing to obtain the superconducting cable, the following steps may also be included: Dipping the twisted conductor skeleton into liquid solder to obtain a dipped conductor skeleton; Inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable may include the following steps: The impregnated conductor skeleton is inserted into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable.

[0046] It should be noted that the process of dipping the twisted conductor frame into the liquid solder can be referred to as "tinning" or "dipping solder". Before dipping the twisted conductor frame into the liquid solder, it can be ensured that the twisted conductor frame is clean and free of grease, oxides or other contaminants to ensure that the solder can be evenly attached. Next, the solder material can be placed in an appropriate container and heated above its melting point to make it liquid. Then, the twisted conductor frame is carefully and slowly dipped into the liquid solder for a certain time to ensure that the solder can fully cover the required area. The speed and depth of dipping can be adjusted according to the specific application requirements. Finally, the twisted conductor frame is removed from the liquid solder and allowed to cool naturally or the formation of the solder layer is promoted by controlling the cooling rate. During the cooling process, the liquid solder solidifies and forms a uniform solder coating on the surface of the conductor frame.

[0047] By applying the solution of the embodiment of the present application, the superconducting cable has a smaller torsion pitch by twisting first and then dipping, thereby reducing the AC loss of the superconducting conductor.

[0048] Step 108: Winding and curing the superconducting cable to obtain a superconducting conductor.

[0049] It should be noted that when winding the superconducting cable, the superconducting cable can be wound into a spiral shape, a ring shape, etc. according to specific application requirements, and then cured to obtain a superconducting conductor.

[0050] In practical applications, when winding superconducting cables, the bending radius is an important parameter in the preparation of superconducting conductors. In order to obtain the minimum bending radius of superconducting conductors during the winding process, simulation calculations can be performed on superconducting conductors. The calculation results are shown in Fig. 9 See Fig. 9 , Fig. 9 A schematic diagram of a bending radius simulation result provided by an embodiment of the present application is shown. Fig. 9 The superconducting stacked tape model on the left is the whole after solder dipping, without twisting, and is close to the irreversible stress of the tape when the bending radius (rr, radius of rotation) is 0.35 meters. Fig. 9 The right side shows the calculation results of the bending strain on the superconducting stacked tape after twisting and bending. The calculation formulas are shown in the following formulas (1) to (3): (1) (2) (3) in, It represents the strain when there is no impregnation and perfect slip between the superconducting stacked tapes; It represents the strain when the superconducting stacked tapes are immersed and there is no slip. Indicates the bending radius, represents the torsion angle per unit length, represents the width distance from the central axis of the superconducting stacked tape, represents the distance to the center axis of the superconducting cable, represents the torsion angle, Indicates the torsion pitch. The minimum bending radius of the superconducting conductor is calculated to be 0.39m (critical strain 0.004) through the torsion pitch of the conductor skeleton of 0.5m. In order to further protect the conductor, in practical applications, the bending radius of the superconducting conductor is greater than or equal to the minimum bending radius of 0.39m, such as 0.44m. represents sine, represents cosine, represents tangent, Is a mathematical constant that represents the ratio of a circle's circumference to its diameter.

[0051] The superconducting conductor obtained by winding using the scheme of the embodiment of the present application refers to a stacked, twisted, and asked rectangular-shaped conductor. Therefore, the wound superconducting conductor can be called a STAR (Stacked Twisted Askew Rectangular-shaped) conductor, which has higher space utilization and can not only achieve transposition and high current density of superconducting tapes, but also has a smaller bending radius and smaller flow resistance.

[0052] In one embodiment of the present application, taking the winding shape of the superconducting cable as a spiral shape as an example, the above-mentioned winding and curing of the superconducting cable to obtain the superconducting conductor may include the following steps: Helically winding the superconducting cable to obtain a wound superconducting cable; The solidified material is filled into the skeleton channel of the superconducting cable after layer winding to obtain a superconducting conductor after the solidified material is solidified.

[0053] It should be noted that spiral layer winding refers to winding the superconducting cable in a spiral form according to a certain bending radius. Spiral layer winding helps to optimize the magnetic field distribution and improve the mechanical stability and current carrying capacity of the superconducting conductor. The superconducting cable after layer winding refers to the superconducting cable after spiral layer winding. Since the superconducting cable after layer winding has been processed by spiral layer winding, the superconducting cable after layer winding is a spiral superconducting cable. After completing the winding of the superconducting cable, in order to further enhance the stability of the superconducting cable structure after layer winding and protect the internal superconducting tape from physical damage or other environmental factors, the superconducting cable after layer winding can be cured. During curing, the skeleton channel of the superconducting cable after layer winding can be filled with curing material. The curing material includes but is not limited to epoxy resin, liquid solder, etc., which is selected according to the actual situation, and the embodiment of the present application does not make any limitation on this. The superconducting conductor after curing by the curing material refers to the filled curing material that hardens after appropriate treatment (such as heating curing) and forms a solid overall structure with the superconducting cable after layer winding. At this point, the superconducting conductor has a certain mechanical strength, thermal stability and electrical properties, and can be used to build high-efficiency superconducting devices such as magnets or power transmission lines.

[0054] For example, taking the solidifying material as liquid solder, after the superconducting cable is spirally wound, the wound superconducting cable can be heated as a whole, and the heated and melted liquid solder can be introduced into the skeleton channel. After the solder solidifies, the preparation of the superconducting conductor can be completed.

[0055] By applying the solution of the embodiment of the present application, the superconducting tape can be well protected by twisting first, bending then winding and then dipping, so that the superconducting conductor has a smaller torsion pitch and bending radius, thereby reducing the AC loss of the superconducting conductor and making the superconducting conductor more compact.

[0056] In one embodiment of the present application, after the superconducting cable is spirally wound, adjacent superconducting cable layers may cause current leakage or short circuit due to contact. In order to avoid this phenomenon, insulating materials may be covered between adjacent superconducting cables, that is, the superconducting cable after layer winding includes multiple cable layers. After the superconducting cable is spirally wound, the following steps may be further included: Between adjacent cable layers, there is covering insulation material.

[0057] It should be noted that insulating materials can also be called dielectric materials, which are materials that can prevent current from passing through electrical equipment. Insulating materials include but are not limited to insulating tapes (such as Teflon tapes, polyimide tapes), epoxy boards, and epoxy resin coatings. The selection is based on actual conditions, and the present application embodiment does not impose any limitation on this.

[0058] In practical applications, the method of covering the insulating material between adjacent cable layers can be selected according to the insulating material. For example, insulating tape can be pasted on the contact surface between adjacent cable layers, or epoxy resin paint can be sprayed on the contact surface between adjacent cable layers, or epoxy board can be placed between adjacent cable layers, etc.

[0059] By applying the solution of the embodiment of the present application, by covering the insulating material between adjacent cable layers, current leakage or short circuit caused by contact between adjacent superconducting cable layers can be effectively avoided, thereby ensuring the safety and reliability of the superconducting conductor.

[0060] See also Fig.10 , Fig.10 A schematic diagram of the structure of a superconducting conductor provided by an embodiment of the present application is shown, wherein the superconducting conductor comprises a conductor skeleton and a conductor skeleton shell, wherein the conductor skeleton comprises a plurality of superconducting stacked tape slots, wherein superconducting stacked tapes are inserted into the plurality of superconducting stacked tape slots, and the conductor skeleton shell comprises a skeleton channel and at least one cooling channel ( Fig.10 There are three in the figure), the skeleton channel is used to insert the twisted conductor skeleton, and the cooling channel is used to fill the cooling material, which is used to cool the superconducting conductor.

[0061] It should be noted that Fig.10The structural description of the superconducting conductor in is a structural description of a single-layer superconducting conductor, and the result of each layer of superconducting conductor is the same. The current carrying capacity of the superconducting conductor is provided by multiple superconducting stacked tapes inserted into the superconducting stacked tape slots, and the multiple superconducting stacked tapes are twisted and inclined. The superconducting stacked tape includes multiple superconducting tapes stacked together.

[0062] In one embodiment of the present application, thin metal tapes are covered above and below the stack of the stacked multiple superconducting tapes, and the thin metal tapes are used to protect the superconducting tapes from being damaged when inserted into the slots of the superconducting stacked tapes.

[0063] In one embodiment of the present application, solder wire is wound around the outside of the superconducting stacked tape, and the solder wire can ensure that the superconducting stacked tape is not easy to spread out during the twisting process.

[0064] In one embodiment of the present application, the conductor skeleton further includes a quench detection channel, and an optical fiber for quench detection of the superconducting conductor is inserted into the quench detection channel.

[0065] In one embodiment of the present application, the conductor skeleton shell is square. Setting the conductor skeleton shell in a square shape can more closely arrange multiple layers of superconducting cables in a limited space, and the square design can more conveniently fix the superconducting cables and reduce the difficulty of winding the superconducting conductor.

[0066] In one embodiment of the present application, the superconducting conductor includes a plurality of cable layers, and the cooling channel is located between adjacent cable layers.

[0067] It should be noted that the cooling channel between adjacent cable layers can be used to conduct cooling for two adjacent cable layers at the same time, so as to quickly reach a low temperature environment for normal flow of superconducting cables. In one embodiment of the present application, an insulating layer composed of insulating material is also included between adjacent cable layers, and the insulating layer is located between the layers of superconducting conductors. Exemplarily, the thickness of the conductor skeleton shell can be 15.88 mm, and the thickness of the insulating layer can be 0.12 mm.

[0068] By applying the solution of the embodiment of the present application, since the twisted conductor skeleton is inserted into the skeleton channel of the superconducting conductor, the superconducting conductor has a higher engineering current density. In addition, since the cooling channel is located in the conductor skeleton shell, the overall cooling effect of the superconducting conductor is high, and it has a higher current density and a lower flow resistance.

[0069] The above is a schematic scheme of a superconducting conductor of this embodiment. It should be noted that the technical scheme of the superconducting conductor and the technical scheme of the superconducting conductor winding method described above are of the same concept, and the details of the technical scheme of the superconducting conductor that are not described in detail can all be referred to the description of the technical scheme of the superconducting conductor winding method described above.

[0070] See also Fig.11 , Fig.11 FIG. 1 shows a schematic diagram of a conductor critical current simulation result provided by an embodiment of the present application. The critical current of the superconducting conductor is simulated and calculated under the condition of 77K self-field. The calculation results are shown in FIG. Fig.11 The critical current of a single superconducting tape under 77K self-field is 135A, and the critical current of the conductor can reach 8.1KA. Under the conditions of 20K and 8T background field, the critical current of the superconducting conductor is calculated to be 34.4kA. Therefore, the rated working current of the superconducting conductor can be set to 20.6kA, and the engineering current density can reach 98 A mm -2 .

[0071] The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0072] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present application are not limited by the described action sequence, because according to the embodiments of the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of the present application.

[0073] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The specification examples do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the embodiments of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the embodiments of the present application, so that those skilled in the art can understand and use the present application well. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A method for winding a superconducting conductor, characterized in that: include: inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton; After the superconducting stacked tape is inserted, twisting the conductor skeleton to obtain a twisted conductor skeleton; Inserting the twisted conductor skeleton into a skeleton channel of a conductor skeleton shell to obtain a superconducting cable, wherein the conductor skeleton shell includes at least one cooling channel; The superconducting cable is wound and cured to obtain a superconducting conductor.

2. The method according to claim 1, characterized in that The step of winding and curing the superconducting cable to obtain a superconducting conductor comprises: Helically winding the superconducting cable to obtain a wound superconducting cable; The solidified material is filled into the skeleton channel of the superconducting cable after the layer winding to obtain the superconducting conductor after the solidified material is solidified.

3. The method according to claim 2, characterized in that The layer-wound superconducting cable comprises a plurality of cable layers; After the superconducting cable is spirally wound to obtain the wound superconducting cable, the method further comprises: Between adjacent cable layers, insulating material is covered.

4. The method according to any one of claims 1 to 3, characterized in that: Before inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton shell to obtain the superconducting cable, the method further comprises: Dipping the twisted conductor skeleton into liquid solder to obtain a dipped conductor skeleton; The method of inserting the twisted conductor skeleton into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable comprises: The impregnated conductor skeleton is inserted into the skeleton channel of the conductor skeleton shell to obtain a superconducting cable.

5. The method according to any one of claims 1 to 3, characterized in that: Before inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton, the method further comprises: A plurality of superconducting tapes are stacked, and metal tapes are covered above and below the stack of the plurality of superconducting tapes to obtain the superconducting stacked tape.

6. The method according to any one of claims 1 to 3, characterized in that: Before inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton, the method further comprises: Winding a solder wire on the outside of the superconducting stacked tape to obtain a fixed superconducting stacked tape; The step of inserting the superconducting stacked tape into the superconducting stacked tape slot of the conductor skeleton comprises: The fixed superconducting stacked tapes are inserted into the superconducting stacked tape slots of the conductor skeleton.

7. The method according to any one of claims 1 to 3, characterized in that: The conductor skeleton also includes a quench detection channel; Before the superconducting cable is wound and solidified to obtain a superconducting conductor, the method further comprises: inserting an optical fiber into the quench detection channel; The step of winding and curing the superconducting cable to obtain a superconducting conductor comprises: The superconducting cable inserted into the optical fiber is wound and solidified to obtain a superconducting conductor.

8. A superconducting conductor, characterized in that: It includes a conductor skeleton and a conductor skeleton shell, the conductor skeleton includes a plurality of superconducting stacked tape slots, superconducting stacked tapes are inserted in the plurality of superconducting stacked tape slots, the conductor skeleton shell includes a skeleton channel and at least one cooling channel, the skeleton channel is used to insert the twisted conductor skeleton, the cooling channel is used to fill cooling material, and the cooling material is used to cool the superconducting conductor.

9. The superconducting conductor according to claim 8, characterized in that The superconducting conductor includes a plurality of cable layers, and the cooling channel is located between adjacent cable layers.

10. The superconducting conductor according to claim 8, characterized in that The conductor skeleton shell is square.

Images