JP7541557B2 - Superconducting wire, its manufacturing method, and superconducting cable including the superconducting wire - Google Patents

Description

One embodiment of the present invention relates to a superconducting wire, a manufacturing method thereof, and a superconducting cable including the superconducting wire.

By using a conductive wire having a superconductor in a power cable, it becomes possible to transmit a large current with low loss compared to existing power cables that are mainly made of copper. Such a superconducting cable has a core material (former) for carrying a coolant such as liquid nitrogen, and has one or more superconducting layers around the former. Each superconducting layer is composed of multiple superconducting tapes wound in a spiral shape (see Patent Documents 1 to 3).

JP 2015-162367 A JP 2016-4612 A JP 2020-114088 A

One of the embodiments of the present invention aims to provide a superconducting wire having a new structure, a manufacturing method thereof, and a superconducting cable including said superconducting wire. Alternatively, one of the embodiments of the present invention aims to provide a formless superconducting wire with high cooling efficiency, a manufacturing method thereof, and a superconducting cable including said superconducting wire.

One embodiment of the present invention is a superconducting wire. The superconducting wire includes a superconducting tape spirally wound to form a tubular shape, an insulating tape having a plurality of openings spirally wound on the superconducting tape, and a reinforcing layer covering an outer surface of the insulating tape and including a resin. A portion of the resin is located in the gaps between adjacent superconducting tapes.

One embodiment of the present invention is a superconducting cable comprising at least one superconducting wire, an internal cooling tube surrounding the at least one superconducting wire, and an external cooling tube surrounding the internal cooling tube. The at least one superconducting wire comprises a superconducting tape spirally wound to form a tubular shape, an insulating tape having a plurality of openings spirally wound on the superconducting tape, and a reinforcing layer covering an outer surface of the insulating tape and including a resin. A portion of the resin is located in the gaps between adjacent superconducting tapes.

One embodiment of the present invention is a method for manufacturing a superconducting wire. The method includes the steps of spirally winding a superconducting tape onto a core, spirally winding an insulating tape having a plurality of openings onto the plurality of superconducting tapes, applying a resin to the outer surface of the insulating tape, and curing the resin.

FIG. 1 is a schematic perspective view of a superconducting wire according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting tape included in the superconducting wire according to the embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting wire according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting wire according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting wire according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting wire according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting cable according to an embodiment of the present invention. FIG. 2 is a schematic end view of a superconducting cable according to an embodiment of the present invention. 3 is a flowchart of a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic side views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic side views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic side views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic end views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic side views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic end views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic side views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic end views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention. 1A to 1C are schematic end views illustrating a method for manufacturing a superconducting wire according to an embodiment of the present invention.

Each embodiment of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in various forms without departing from the spirit of the invention, and should not be interpreted as being limited to the description of the embodiments exemplified below.

In the drawings, the width, thickness, shape, etc. of each part may be shown diagrammatically compared to the actual embodiment in order to make the explanation clearer, but this is merely an example and does not limit the interpretation of the present invention. In this specification and each figure, elements having the same function as those explained in the previous figures may be given the same reference numerals and duplicate explanations may be omitted. This reference numeral is used to collectively represent multiple identical or similar structures, and a hyphen and a natural number are added after the reference numeral when representing each of these individually. In addition, a lowercase alphabet may be added after the reference numeral when indicating part of a structure.

The following describes a superconducting wire according to one embodiment of the present invention, a method for manufacturing the same, and a superconducting cable including the superconducting wire.

1. Structure of the superconducting wire FIG. 1A shows a schematic side view of a superconducting wire 100 according to one embodiment of the present invention. As shown in FIG. 1A, the superconducting wire 100 basically includes a superconducting tape 102, an insulating tape 106 provided to surround the superconducting tape 102, and a reinforcing layer 104 provided to surround the insulating tape 106. The superconducting wire 100 may have a straight shape without bending from one end to the other end as shown in FIG. 1A, or may be curved overall (not shown). Alternatively, the superconducting wire 100 may have a plurality of straight portions extending in different directions so as to have one or a plurality of bending points. In the following description, for convenience, the direction in which the superconducting wire 100 extends is defined as the x direction, and the directions perpendicular to the x direction and perpendicular to each other are defined as the y direction and the z direction. There is no restriction on the length (length in the x direction) of the superconducting wire 100. There is no restriction on the outer diameter (length in the z direction in the drawing) of the superconducting wire 100. The above configuration will be described below.

(1) Superconducting Tape The superconducting tape 102 is wound in a spiral shape to form a tube shape. In the superconducting wire 100, there is no restriction on the number of superconducting tapes 102 constituting the superconducting tape layer, and the number may be, for example, 10 or more, as long as it is at least one. In the example shown in FIG. 1A, a single superconducting tape layer in the superconducting wire 100 is formed using a plurality of superconducting tapes 102, and each of the plurality of superconducting tapes 102 has a spiral shape, and the spiral winding direction is the same. In addition, the pitch and radius of the spiral are the same or substantially the same between the plurality of superconducting tapes 102. As shown in FIG. 1A, there is a gap between adjacent superconducting tapes 102, and the adjacent superconducting tapes 102 do not directly contact each other. The width of the gap (i.e., the distance between adjacent superconducting tapes 102) may be appropriately adjusted within a range of 500 μm to 5 mm. In the example shown in FIG. 1A, a single superconducting tape layer is provided using a plurality of superconducting tapes 102, but two superconducting tapes 102 may be provided in layers.

FIG. 1B shows an example of a schematic diagram of an end face of the superconducting tape 102. As shown in FIG. 1B, the superconducting tape 102 can include a substrate 110, an intermediate layer 112 on the substrate 110, a superconducting layer 114 on the intermediate layer 112, and a protective layer 116 on the superconducting layer 114. The substrate 110 includes a metal, and examples of the substrate include a metal substrate or an alloy substrate including iron, nickel, molybdenum, chromium, molybdenum, and the like. Examples of the alloy include stainless steel, invar, and inconel. The intermediate layer 112 can be configured as a laminate of a plurality of oxides with controlled crystal orientation, and examples of the oxide include CeO ₂ , LaMnO ₃ , MgO, Y ₂ O ₃ , and Gd ₂ Zr ₂ O _7. The superconducting layer 114 is a film including an oxide-based superconductor containing Y, Ba, Cu, and O, and forms a conductive path of the superconducting tape 102. The protective layer 116 is a thin film containing a metal such as copper or silver. The thickness of the superconducting tape 102 is, for example, 100 μm or more and 500 μm or less. The superconducting tape 102 may be wound so that the protective layer 116 is disposed inside the tubular shape, or conversely, may be wound so that the protective layer 116 is disposed outside the tubular shape. As will be described later, the superconducting wire 100 can be cooled by supplying liquid nitrogen to the inside of the tubular shape formed by the superconducting tape 102. For this reason, it is preferable that the superconducting tape 102 is wound so that the protective layer 116 side having high thermal conductivity is in contact with liquid nitrogen, that is, so that the protective layer 116 is disposed inside the tubular shape.

The above-mentioned superconducting tape 102 is a tape in which an yttrium-based superconductor is formed, but a tape containing a bismuth-based superconductor containing Bi, Sr, Ca, Cu, and O may also be used as the superconducting tape 102. In this case, although not shown, the superconducting tape 102 may have a structure in which, for example, filaments of a bismuth-based superconductor are disposed in an alloy containing silver. Note that the structure of the superconducting tape 102 shown in FIG. 1B is one example and is not limited thereto, and the superconducting tape 102 constituting the superconducting wire 100 may be a known superconducting tape.

(2) Insulating Tape The insulating tape 106 is formed by winding a tape-shaped insulating base material in a spiral shape, and is fixed to the superconducting tape 102 by a reinforcing layer 104 described later. The insulating base material is a cloth made of glass fiber or polymeric fibers such as polyimide, polyamide, polyester, polyethylene, and polypropylene, and therefore, as described later, the insulating tape has a plurality of openings due to gaps in the fibers. The insulating tape 106 may be, but is not limited to, a glass tape. The insulating tape 106 may have a thickness of, for example, 1 mm or less before being wound on the superconducting tape 102.

The insulating tape 106 is arranged in a spiral shape so as to surround the superconducting tape 102. In addition, it is preferable to wind the insulating tape 106 so that a part of the insulating tape 106 contacts another part or an overlapping part is formed when the insulating tape 106 goes around the outside of the tube shape formed by the superconducting tape 102, so as not to form a gap in the longitudinal direction of the superconducting wire 100. In other words, it is preferable to wind the insulating tape 106 so that the spiral pitch of the insulating tape 106 is equal to or less than the width of the insulating tape 106. For example, the insulating tape 106 can be wound in a so-called 1/2 lap winding, in which the insulating tape 106 is wound with half the tape width overlapping each other. By forming the insulating tape 106 in this way, the strength of the superconducting wire 100 can be increased. Note that the insulating tape 106 after winding is formed to have a predetermined thickness according to the insulation performance required for the superconducting wire 100 (or for the superconducting cable described later).

(3) Reinforcement layer The reinforcement layer 104 is a cured resin, and by exhibiting a certain strength after curing, the superconducting wire 100 can be made to stand on its own. Here, being independent means that the shape is maintained without depending on the arrangement direction even without using a support member (e.g., a former). There is no restriction on the structure of the resin, and for example, epoxy resin, acrylic resin, urethane resin, diallyl phthalate resin, phenolic resin, etc. can be used. The resin may be thermosetting or photosetting, or may be a so-called two-liquid resin in which two types of liquid are mixed and cured at room temperature. Preferably, a thermosetting epoxy resin is used, which is inexpensive and has a relatively high curing speed. For example, as the resin used for the reinforcement layer 104, an epoxy resin-based adhesive, a two-liquid mixture type that is made by mixing a base agent containing an oligomer having multiple epoxy groups in the molecule and a curing agent containing a crosslinking agent and curing at room temperature, can be used. The amount of resin used in the reinforcing layer 104 should be just the amount needed to fix the insulating tape 106 and position the resin in the gap between adjacent superconducting tapes, and the thickness of the reinforcing layer 104 formed is not particularly limited. However, if the reinforcing layer 104 is required to have the insulating performance of the superconducting wire 100, it may be formed thicker by using more resin than the amount needed.

Here, as shown in a schematic diagram of an end face in a yz plane perpendicular to the x direction (FIG. 1C), the insulating tape 106 is provided on the superconducting tape 102 (i.e., on the outer surface of the superconducting tape 102, on the outer circumference of the tube shape formed by the superconducting tape 102), and contacts the superconducting tape 102 and the reinforcing layer 104. Also, as shown in an enlarged view (FIG. 2A) of region _R1 in FIG. 1C, a part of the reinforcing layer 104, i.e., a part of the resin (e.g., the resin of the epoxy resin adhesive) contained in the reinforcing layer 104, is also present in the gap between the adjacent superconducting tapes 102 wound in a spiral shape. Therefore, the side surfaces of the superconducting tapes 102 can also be fixed to each other by the reinforcing layer 104, and the strength of the superconducting wire 100 can be further increased. Note that, as shown in FIGS. 2B and 2C, a part of the resin of the reinforcing layer 104 may further cover the whole or a part of the inner surface of the superconducting tape 102.

As described above, the superconducting wire 100 has the outer surface of the spirally wound superconducting tape 102 fixed with the insulating tape 106, and the outer surface of the insulating tape 106 is covered with the reinforcing layer 104. A part of the resin of the reinforcing layer 104 is also present in the gap between the adjacent superconducting tapes 102, so that the sides of the superconducting tapes 102 can be fixed together. Therefore, the superconducting wire 100 can not only have a self-supporting strength, but also will not be damaged even if liquid nitrogen is poured inside. Because of such characteristics, as described below, in a superconducting cable including the superconducting wire 100, it is not necessary to place a former for pouring liquid nitrogen. This feature makes it possible to form the superconducting cable thinner (reducing the diameter) and contributes to reducing the manufacturing cost by reducing the number of parts. In order to improve the mechanical strength of the superconducting wire 100, a further reinforcing layer may be provided on the outer periphery of the reinforcing layer 104. In addition, when the superconducting wire 100 is used at a voltage of 3300 V or more, a semiconducting layer may be provided on the outside of the superconducting tape 102, and then the insulating tape 106 and the reinforcing layer 104 may be provided on the outside of the semiconducting layer. The semiconducting layer may be configured so that the insulating tape 106 and the reinforcing layer 104 of the embodiment each contain carbon or the like.

2. Superconducting Cable One embodiment of the present invention is a superconducting cable including at least one superconducting wire 100. A superconducting cable may include a plurality of superconducting wires 100. Schematic yz end views of superconducting cables 120, 121 according to one embodiment of the present invention are shown in Figures 3A and 3B, respectively. In these figures, for ease of viewing, each superconducting wire 100 is shown with the superconducting tape 102, the insulating tape 106, and the reinforcing layer 104 integrated together.

The superconducting cable 120 shown in FIG. 3A is a three-phase coaxial superconducting cable having three superconducting wires 100 of different sizes (first superconducting wire 100-1A, second superconducting wire 100-2A, third superconducting wire 100-3A) arranged concentrically. The first superconducting wire 100-1A (e.g., U phase) is inserted and arranged within the second superconducting wire 100-2A (e.g., V phase), and the second superconducting wire 100-2A (e.g., V phase) is inserted and arranged within the third superconducting wire 100-3A (e.g., W phase). An insulating layer 122 for establishing electrical insulation is provided between adjacent superconducting wires 100 and on the outside of the outermost third superconducting wire 100-3A (e.g., W phase). In the superconducting cable 120 shown in FIG. 3A, an insulating layer 122 is provided, but if the insulating strength of the superconducting cable 120 is sufficient with the insulating performance of the superconducting wire 100, the insulating layer 122 may not be provided. Note that the superconducting cable having a concentric shape may be provided with superconducting wires forming three phases, for example, U-phase, V-phase, and W-phase, in one superconducting cable, and all of the superconducting wires of the three phases may not be strictly coaxial. The insulating layer 122 may adopt a structure in which insulating paper such as polypropylene semi-synthetic paper, other plastic laminated paper, craft paper, or plastic tape is wound in layers, and may be formed by extrusion of an insulating material. A shielding layer 124 formed by winding the superconducting tape 102 in a spiral shape may be arranged on the outside of the outermost insulating layer 122. Note that the shielding layer 124 may be omitted when not used at high voltage, specifically when used as a superconducting cable of a voltage class of less than 3300V. In addition, when used as a superconducting cable for a voltage class of 3300 V or more, a semiconducting layer (not shown) may be provided on the outside of the insulating layer 122 so as to be in contact with the inside of the shielding layer 124. This semiconducting layer may be made of a material known as a semiconducting layer for superconducting cables.

On the outside of the three superconducting wires 100 (outside the shielding layer 124 in FIG. 3A), an internal cooling pipe 126 that surrounds the third superconducting wire 100-3A (surrounding the shielding layer 124 in FIG. 3A) and an external cooling pipe 128 that surrounds the internal cooling pipe 126 are provided. The internal cooling pipe 126 and the external cooling pipe 128 may be corrugated pipes containing aluminum, for example. A reduced pressure is maintained between the internal cooling pipe 126 and the external cooling pipe 128, thereby suppressing the rise in temperature of the liquid nitrogen flowing in the superconducting cable 120. The liquid nitrogen is supplied to the internal space 100a formed by the first superconducting wire 100-1A and the space between the shielding layer 124 and the internal cooling pipe 126.

In the superconducting cable 121 shown in Figure 3B, unlike the concentric superconducting cable 120 shown in Figure 3A, multiple superconducting wires 100 are arranged within a shielding layer 124. The example shown in Figure 3B shows the structure of a three-phase (three-core) superconducting cable 121 in which three superconducting wires 100 (first superconducting wire 100-1B, second superconducting wire 100-2B, third superconducting wire 100-3B) of similar sizes are arranged within one superconducting cable 121. Each of the three superconducting wires 100 (first superconducting wire 100-1B, second superconducting wire 100-2B, third superconducting wire 100-3B) may not be of the same size, but may be of different sizes. In FIG. 3B, the superconducting wires 100 (first superconducting wire 100-1B, second superconducting wire 100-2B, third superconducting wire 100-3B) are arranged so that their central axes are located at the vertices of an equilateral triangle, but the arrangement is not limited as long as the central axes of the superconducting wires 100 are located at different positions. Although not shown in FIG. 3B, an insulating layer for insulating the superconducting wires 100 may be provided around each superconducting wire 100. In addition, as an optional configuration, a spacer 132 for physically isolating the superconducting wires 100 may be arranged as shown in FIG. 3B, or the spacer 132 may be omitted. If the spacer 132 is not present, it is desirable to have a structure in which the superconducting wires 100-1B, 100-2B, and 100-3B are in contact with each other.

The other configurations are the same as those of the superconducting cable 120, and an insulating layer 122 is provided to surround the multiple (three in FIG. 3B) superconducting wires 100, and a shielding layer 124 is provided to surround the insulating layer 122, as well as an internal cooling tube 126 and an external cooling tube 128 that surround the multiple superconducting wires (surrounding the shielding layer 124 in FIG. 3B). In the superconducting cable 121 shown in FIG. 3B, the insulating layer 122 is provided, but if the insulating performance of the superconducting wire 100 is sufficient to provide the insulating strength of the superconducting cable 121, the insulating layer 122 may not be provided. If the insulating layer 122 is not provided in the superconducting cable 121, a pressing tape is wound around the outer circumference of the three superconducting wires 100. In addition, the shielding layer 124 may be omitted when not used at high voltage, specifically when used as a superconducting cable of a voltage class of less than 3300V. In addition, when the cable is used as a superconducting cable of a voltage class of 3300V or more, a semiconducting layer (not shown) may be provided on the outside of the insulating layer 122 so as to contact the inside of the shielding layer 124. This semiconducting layer may be formed of a material known as a semiconducting layer for a superconducting cable. Liquid nitrogen can be flowed between the internal space 100a formed by each superconducting wire 100, the shielding layer 124, and the internal cooling pipe 126, and liquid nitrogen can also be flowed inside the insulating layer 122. When liquid nitrogen is flowed, for example, in the superconducting cable 120 shown in FIG. 3A, the internal space 100a can be used as the forward path and the space between the shielding layer 124 and the internal cooling pipe 126 can be used as the return path, and in the superconducting cable 121 shown in FIG. 3B, the internal space 100a can be used as the forward path and the space inside the insulating layer 122, outside each superconducting wire 100, and the space between the shielding layer 124 and the internal cooling pipe 126 can be used as the return path. If the insulating layer 122 and the shielding layer 124 are not provided, the entire outside of each superconducting wire 100 (the inside of the pressure tape on the outside of the superconducting wire 100, and between the pressure tape and the internal cooling pipe 126) can be used as a return path. This allows for highly efficient cooling.

As described above, in the superconducting cables 120 and 121, the liquid nitrogen for cooling the superconducting wire 100 flows inside the tube-shaped portion formed by the superconducting tapes 102 that constitute each superconducting wire 100, and can cool the superconducting tapes 102 directly or through the resin of the reinforcing layer 104. Therefore, the superconducting wire 100 can be cooled more efficiently, and even slight temperature increases during current flow can be reliably suppressed. Furthermore, since the insulating tape 106 and the reinforcing layer 104 give the superconducting wire 100 sufficient strength to stand on its own, there is no need to form a former for flowing liquid nitrogen inside the superconducting wire 100. This contributes to a reduction in the number of parts and manufacturing costs, and also enables the superconducting cable to be made smaller in diameter.

3. Method for Manufacturing Superconducting Wire An example of a method for manufacturing the superconducting wire 100 will be described with reference to the flow chart of Fig. 4 and the schematic diagrams of Figs. 5A to 7C.

First, prepare a core 130 for winding the superconducting tape 102 in a spiral shape (FIG. 5A). The core 130 has a cylindrical or tubular shape with a circular or substantially circular end face in the yz plane, and is, for example, a metal, glass, or resin rod or tube. The core 130 only needs to have a strength that does not substantially deform, or may be configured to undergo plastic or elastic deformation. Alternatively, a spiral core may be used in combination. The spiral core is formed by connecting multiple ribbons, and is a jig that is wound up in a spiral shape to form a tube shape, and can be deformed from the tube shape to a linear shape by unwinding it from the end. For example, in order to maintain the spiral core in a straight line, a straight rod may be passed through the inside of the spiral core, and the rod and the spiral core may be used in combination to form the core 130. Note that a pipe may be used as the straight rod. Also, a spiral tube may be wrapped around the outer circumference of a straight rod (or pipe) without using a spiral core. A spiral tube is a member that is generally used to organize and bundle wiring by wrapping it around electric wires, cables, cords, etc. Spiral tubes can be made from plastics such as nylon, polyethylene, and fluororesin. Spiral tubes are made from ribbons that are formed in a helical shape, but unlike spiral cores, the ribbons are not connected to each other and have elasticity.

After this, a release material 134 is provided on the surface of the core 130 (FIG. 5B), and then the superconducting tape 102 is wound in a spiral shape around the core 130 (on which the release material 134 is provided) (FIG. 5C). A predetermined number of superconducting tapes 102 are used, arranged at a predetermined pitch, and wound while applying a predetermined tension so that the superconducting surfaces are located inside and do not come into contact with each other. As shown in FIG. 5B, the release material 134 may be formed by winding a tape containing a fluorine-based resin such as polytetrafluoroethylene (PTFE) in a spiral shape around the core 130, or may be formed by applying, for example, silicone oil, a surfactant, a fluorine-based resin, or the like. The release material 134 does not have to be provided (or applied) on the surface of the core 130, but the use of the release material 134 makes it easier to remove the core 130, which will be described later.

Figure 5D shows a schematic diagram of the yz end surface when the superconducting tape 102 is wound. As shown in Figure 5D, the superconducting tape 102 is wound around the outer circumference of the core 130 directly or via a release material 134 so that there is a gap 102a between adjacent superconducting tapes 102. Through the process up to this point, a tubular shape is formed by the superconducting tape 102.

Subsequently, the insulating tape 106 (e.g., glass tape) is wound in a spiral shape on the superconducting tape 102 (FIGS. 6A and 6B). As described above, in order to provide the superconducting wire 100 with strength that allows it to stand on its own, it is preferable to wind the insulating tape 106 so that the pitch of the spiral structure formed by the insulating tape 106 is equal to or less than the width of the insulating tape 106. For example, as shown in the enlarged view of region _R2 in FIG. 6A, the insulating tape 106 is wound so that an overlapping portion 106c is formed between a part 106a and another part 106b of the insulating tape 106. For example, the insulating tape 106 may be wound in a so-called 1/2 lap winding in which the insulating tape 106 is wound so as to overlap half of the tape width.

After this, the resin constituting the reinforcing layer 104 is applied to the outer surface of the insulating tape 106 (FIGS. 7A and 7B). As shown in the enlarged view of region _R3 in FIG. 6A, the insulating tape 106 has a plurality of openings 106d which are gaps between the fibers constituting the base material. Therefore, the resin before hardening (resin mixed with a base agent and a hardener when a two-liquid mixed epoxy adhesive is used) permeates the superconducting tape 102 side from the openings 106d of the insulating tape 106 and spreads between the adjacent superconducting tapes 102. Furthermore, the resin before hardening can spread into the gap between the superconducting tape 102 and the core 130 and/or the gap between the release material 134 and the core 130 due to the capillary phenomenon. Therefore, as shown in FIG. 2B and FIG. 2C, a part of the resin contained in the reinforcing layer 104 can be located between the adjacent superconducting tapes 102 or on a part or the entire inner surface of the superconducting tape 102.

Then, the resin is cured to form the reinforcing layer 104. At this time, the uncured resin may be covered with a protective tape 136 to hold the uncured resin on the insulating tape 106 so as not to drip (FIG. 7C). The protective tape 136 may be formed of a tape containing a polymer such as polyvinyl chloride, polyvinylidene chloride, or polyethylene. For example, a commercially available polyvinyl chloride tape may be used. There are no limitations on the thickness of the protective tape 136, as long as it is capable of holding the uncured resin on the insulating tape 106 so as not to drip.

After the resin has hardened, the protective tape 136 and the core 130 are successively removed (if the release material 134 is formed from tape, the release material 134 is also removed), to obtain the superconducting wire 100.

When manufacturing a curved superconducting wire 100, the superconducting tape 102 is wound around a straight core 130 capable of plastic deformation, the core 130 is then curved, and the insulating tape 106 is then wound around the superconducting tape 102, and a resin (e.g., adhesive) that will become the reinforcing layer 104 is applied onto the insulating tape 106. After that, the protective tape 136 is further wound around the superconducting wire 100, and the resin is hardened to form the reinforcing layer 104. The protective tape 136 is then removed to obtain the curved superconducting wire 100.

In order to prevent further deformation of the core 130 when it is removed, it is preferable to use a plastically deformable flexible tube and a spiral tube assembled to surround the flexible tube in a spiral shape as the core 130. In this case, the release material 134 may be formed on the spiral tube. By removing the flexible tube after the resin has hardened and then releasing the spiral shape of the spiral tube, it is possible to prevent the application of a force that would further deform the superconducting wire 100. As a result, the curved shape before the resin hardened is maintained.

Specifically, a spiral tube is wound around the outer periphery of a curved flexible tube (e.g., a plastic hose) that can be plastically deformed, and a core 130 is prepared. A tape as a release material 134 is wound around the outer periphery of the core 130 (e.g., the outer periphery of the spiral tube), for example, with 1/2 wrap. Note that the release material 134 does not have to be formed on the core 130, but using the release material 134 makes it easier to remove the core 130. Here, the core 130 is made straight, and a predetermined number of superconducting tapes 102 are arranged at a predetermined pitch, and while applying a predetermined tension, the superconducting surfaces are positioned inside and are wound so as not to come into contact with each other. After winding the superconducting tape 102, the core 130 is returned to a curved state. Then, an insulating tape 106 (e.g., a glass tape) is wound around the superconducting tape 102 in a spiral shape, for example, with 1/2 wrap. The resin of the reinforcing layer 104 (e.g., an epoxy resin adhesive) is thinly applied to the entire length and circumference of the insulating tape 106. To hold the uncured resin of the reinforcing layer 104 on the insulating tape 106, a protective tape 136 (e.g., a polyvinyl chloride tape) is wrapped around and covered with the uncured resin. When the resin of the reinforcing layer 104 hardens, the insulating tape 106 is fixed in place. After the resin of the reinforcing layer 104 hardens, the protective tape 136, core 130, release material 134, and spiral tube are sequentially removed to produce a curved superconducting wire 100.

The superconducting tape 102 is flexible enough that it cannot stand on its own. However, by applying the manufacturing method described above, it is possible to manufacture a superconducting wire 100 that can maintain the tubular shape formed by the superconducting tape 102 and has the strength to allow liquid nitrogen to flow inside. Therefore, by implementing the present invention, it is possible to provide a small-diameter formless superconducting wire with high cooling efficiency, and a superconducting cable including this superconducting wire.

The above-described embodiments of the present invention may be combined as appropriate to the extent that they are not mutually inconsistent. In addition, a display device according to any of the embodiments may be combined as appropriate by a person skilled in the art to add or remove components or modify the design, or to add or omit processes or modify conditions, and this is also included in the scope of the present invention as long as it satisfies the gist of the present invention.

Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, if they are clear from the description in this specification or can be easily predicted by a person skilled in the art, they are naturally understood to be brought about by the present invention.

100: Superconducting wire, 100-1A, 100-1B: First superconducting wire, 100-2A, 100-2B: Second superconducting wire, 100-3A, 100-3B: Third superconducting wire, 102: Superconducting tape, 104: Reinforcing layer, 106: Insulating tape, 106a: Part of insulating tape, 106b: Part of insulating tape, 106c: Overlapped portion, 106d: Opening, 110: Substrate, 112: Intermediate layer, 114: Superconducting layer, 116: Protective layer, 120: Superconducting cable, 121: Superconducting cable, 122: Insulating layer, 124: Shielding layer, 126: Internal cooling tube, 128: External cooling tube, 130: Core, 132: Spacer, 134: Release material, 136: Protective tape

Claims (14)

a superconducting tape spirally wound to form a tubular shape;
an insulating tape having a plurality of openings and wound in a spiral shape on the superconducting tape; and a reinforcing layer covering an outer surface of the insulating tape and containing a resin,
A superconducting wire, wherein a portion of the resin is located in a gap between adjacent superconducting tapes. The superconducting wire according to claim 1, wherein another portion of the resin is located on the inner surface of at least a portion of the superconducting tape. The superconducting wire of claim 1, wherein the insulating tape contains glass fibers. The superconducting wire of claim 1, wherein the tubular shape is curved. At least one superconducting wire;
an inner cooling tube surrounding the at least one superconducting wire; and an outer cooling tube surrounding the inner cooling tube,
The at least one superconducting wire comprises:
a superconducting tape spirally wound to form a tubular shape;
an insulating tape having a plurality of openings and wound in a spiral shape on the superconducting tape; and a reinforcing layer covering an outer surface of the insulating tape and containing a resin,
A superconducting cable, wherein a portion of the resin is located in a gap between adjacent superconducting tapes. The superconducting cable according to claim 5, wherein the tube shape is curved. The superconducting cable of claim 5, configured so that liquid nitrogen flows through the tubular shape so as to contact the inner surface of the superconducting tape. the at least one superconducting wire includes a plurality of superconducting wires of different sizes;
The superconducting cable according to claim 5 , wherein each of the plurality of superconducting wires is arranged concentrically. the at least one superconducting wire comprises a plurality of superconducting wires;
6. The superconducting cable according to claim 5, wherein the plurality of superconducting wires are arranged in the internal cooling pipe such that the central axes of the superconducting wires are positioned at different positions. winding the superconducting tape in a spiral shape onto a core;
spirally winding an insulating tape having a plurality of openings onto the superconducting tape;
A method for manufacturing a superconducting wire, comprising: applying a resin to an outer surface of the insulating tape; and curing the resin. The method for producing a superconducting wire according to claim 10, further comprising forming a release material on the core before winding the superconducting tape around the core. A curved core is used as the core,
Before winding the superconducting tape on the core,
Straightening the core, or
The method for producing a superconducting wire according to claim 10, further comprising forming a release material on the core and then straightening the core. The method for manufacturing a superconducting wire according to claim 12, further comprising bending the core after winding the superconducting tape onto the core and before winding the insulating tape onto the superconducting tape. The method for manufacturing a superconducting wire according to claim 10, further comprising wrapping a protective tape over the resin before curing the resin.

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