CN114999730A - Large-current high-temperature superconducting conductor based on center skeleton of stranded cable structure - Google Patents

Abstract

The invention discloses a large-current high-temperature superconducting conductor based on a central framework of a stranded cable structure. The conductor structure includes: the cable comprises a full-cable central framework, a plurality of high-temperature superconducting sub-cables, a full-cable protective wrapping and a metal armor, wherein the full-cable central framework is formed by a metal cable formed by multi-stage stranded cables or a perforated stainless steel pipe or a perforated copper pipe or a spiral structure wound by stainless steel narrow strips. The high-temperature superconducting sub-cable is respectively of the following structures from inside to outside: the high-temperature superconducting tape comprises a sub-cable central framework, a sub-cable central framework wrapping, and a high-temperature superconducting tape and a sub-cable wrapping. The sub-cable central skeleton is formed by metal strand wires through multi-stage stranding; and the high-temperature superconducting strip is wound on the center skeleton of the sub-cable. The invention has compact structure, the conductor has self-supporting function and high current carrying capacity in high field, and can reduce the alternating current loss of the conductor, improve the flexibility of the conductor and enhance the cooling capacity of the conductor, thereby improving the stability margin and the operation reliability of the high-temperature superconducting conductor.

Description

Large-current high-temperature superconducting conductor based on central framework of stranded cable structure

Technical Field

The invention belongs to the technical field of high-temperature superconduction, and particularly relates to a structural design of a large-current high-temperature superconducting conductor based on a central framework of a stranded cable structure.

Background

Superconducting materials refer to conductors that have zero electrical resistance at a certain temperature. The superconducting coil prepared by using the superconducting material has the advantages of high efficiency, low loss, high transmission current density, large irreversible field and the like, so the superconducting coil has a huge application prospect in the field of electric power. With the increase in human productivity and living standards, the demand for energy has increased, with the production of nuclear energy using nuclear fusion being widely focused and studied as a cleaner and more reliable means. The final goal of nuclear energy generation by nuclear fusion is to realize controllable nuclear fusion, and the most possible way to realize the goal is to apply restraint to high-temperature fusion fuel by means of magnetic field, namely, magnetic restraint fusion. In a magnetic confinement fusion device, in order to ensure that high-parameter plasma can safely and stably operate, a superconducting magnet made of superconducting materials is required to generate a strong magnetic field with a specific configuration to confine the high-parameter plasma. Since Dr.Ennesian in 1911 discovered that the resistance of mercury is almost zero at 4.2K or less, he then tried to obtain a strong magnetic field by using a coil made of superconducting material lead (which has superconducting properties at 7.2K), but even at 4.2K, the coil was found to lose superconductivity after generating a magnetic field of 0.055T, because the critical magnetic field of the pure metal superconductor found earlier was low. It is shown that when a strong magnetic field is obtained by the superconducting magnet, the superconducting material selected by the magnet needs to have a higher critical magnetic field, so that the high-temperature superconducting material has great application potential in the next generation of fusion demonstration reactor magnets.

In recent years, the most notable of high-temperature superconducting materials are bismuth-Based (BSCCO) prepared by a bismuth-strontium-calcium-copper oxide powder tube-filling method and superconductors made of rare earth barium-copper oxide (REBCO), which are first-generation and second-generation high-temperature superconducting materials respectively. However, since the superconducting performance of the first generation of high temperature superconducting materials is limited by the irreversible field with a lower magnitude, the second generation of high temperature superconducting materials have the advantages of high current carrying capacity at a higher temperature and a higher irreversible field value compared with the first generation of high temperature superconducting materials. In the fusion device, because the superconducting magnet is in a complex transient electromagnetic environment, the performance requirement on the magnet is higher, and therefore, the high-temperature superconducting conductor can meet the performance requirement by designing a proper structure of the high-temperature superconducting conductor, so that the safety and stability of the superconducting magnet in long-term work are ensured.

Disclosure of Invention

The invention aims to provide a large-current high-temperature superconducting conductor based on a central framework of a stranded cable structure, which has high current carrying capacity and low alternating current loss in a high field while ensuring a compact structure, and can improve the flexibility of the conductor and enhance the cooling capacity of the conductor, thereby improving the stability margin and the operation reliability of the high-temperature superconducting conductor.

In order to achieve the purpose, the invention provides the following technical scheme:

a large-current high-temperature superconducting conductor based on a stranded cable structure central framework comprises a full cable central framework, a plurality of high-temperature superconducting sub-cables wound on the full cable central framework, a full cable protection wrapping and a metal armor wrapping the outermost sides of the plurality of high-temperature superconducting sub-cables; the central skeleton of the whole cable is a metal cable formed by multi-stage stranded cables, a spiral pipe wound by a stainless steel band, a perforated stainless steel pipe or a perforated copper pipe, and the surface of a folded yarn in the metal cable is plated with a high-resistance layer material; the plurality of high-temperature superconducting sub-cables consist of sub-cable central frameworks, sub-cable central framework wrapping, high-temperature superconducting strips and sub-cable wrapping; the central skeleton of the sub-cable is formed by metal strand wires through multi-stage stranding, and the surfaces of the metal strand wires are plated with high-resistance layer materials; the sub-cable central framework is wrapped by a metal belt and wound on the sub-cable central framework; the multilayer high-temperature superconducting strip is wound on the outer side of the wrapping of the sub-cable central framework; the sub-cables are wrapped into metal strips and arranged on the outer sides of the high-temperature superconducting strips.

Further, after the high-temperature superconducting sub-cable is fixed on the central framework of the whole cable through a stranded cable, the outermost layer of the high-temperature superconducting sub-cable is covered with the whole cable, and then the high-temperature superconducting sub-cable penetrates into the metal armor.

Further, the high-resistance layer material may be nickel, chromium or tin.

Further, the metal belt wrapped by the sub-cable is a stainless steel belt or a copper belt, the copper belt is plated with a high-resistance layer material, and the high-resistance layer material is nickel, chromium or tin.

Compared with the prior art, the invention has the beneficial effects that:

the invention aims to provide a large-current high-temperature superconducting conductor based on a stranded cable structure central framework, which can control the size of alternating current loss and provide a stable matrix for the conductor due to the adoption of the central framework made of metal stranded wire multistage stranded cables and the selection of a high-resistance layer material and the thickness of the surface of the metal stranded wire, so that the high-temperature superconducting conductor can operate in alternating current or a changing magnetic field; meanwhile, the flexibility of the high-temperature superconducting conductor can be improved by the central framework made of the metal stranded wire multistage stranded cable; the porosity of the framework can be adjusted by selecting metal strands with different diameters and the pitch of the stranded cables; the wrapping structures of the full-cable central framework and the sub-cable central framework can improve the degradation of superconducting performance caused by stress strain, and can control the resistance between the sub-cables by selecting the thicknesses of different metal strip materials or different coating materials and different coating materials, so that the alternating current loss is further controlled, and the stability margin and the working reliability of the high-temperature superconducting conductor are improved.

Drawings

FIG. 1 is a schematic view of the overall structure of a high-current high-temperature superconducting conductor according to an embodiment of the present invention;

FIG. 2 is a schematic view of a high temperature superconducting sub-cable according to an embodiment of the present invention;

in the figure: 1. a full cable central skeleton; 2. a high temperature superconducting sub-cable; 3. full cable protection wrap; 4. a metal armor; 5. a sub-cable central skeleton; 6. wrapping the central skeleton of the sub-cable; 7. a high temperature superconducting tape; 8. and (5) wrapping the sub-cables.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in figures 1 and 2, the large-current high-temperature superconducting conductor based on the stranded cable structure central framework comprises a full-cable central framework 1, high-temperature superconducting sub-cables 2 wound on the full-cable central framework 1, full-cable protective wraps 3 and metal armors 4 wound on the outermost sides of the high-temperature superconducting sub-cables 2. The high-temperature superconducting sub-cable 2 mainly comprises a sub-cable central framework 5, a sub-cable central framework wrapping 6, a plurality of layers of high-temperature superconducting strips 7 and a sub-cable wrapping 8. The sub cable center framework wrapping 6 is a metal belt and is wound on the sub cable center framework 5; the multilayer high-temperature superconducting tape 7 is wound on the outer side of the sub-cable central skeleton wrapping 6; the sub-cable wrapping 8 is a metal belt and is arranged on the outer side of the high-temperature superconducting strip 7.

As shown in fig. 1, the full cable central skeleton 1 is composed of a metal cable formed by multi-stage twisted cables, a spiral pipe wound by stainless steel bands, a perforated stainless steel pipe or a copper pipe, so as to stabilize the cable structure. The metal cable can be used as a stable matrix, and the porosity between the metal cables can be adjusted by selecting the metal strands with different diameters and the torque of the stranded cable to be used as a channel of a coolant. The high-temperature superconducting sub-cable 2 is twisted on the full-cable central framework 1, and the current carrying capacity of the high-temperature superconducting conductor can be improved by adopting a plurality of high-temperature superconducting sub-cables; then, the whole-cable protection wrapping 3 is implemented on the outermost layer of the high-temperature superconducting sub-cables 2 so as to fix the sub-cables and protect the sub-cables during cable penetration, and meanwhile, the resistance among the sub-cables can be controlled by selecting different metal strip materials and the thicknesses thereof or plating high-resistance layer materials on the surfaces of the metal strip materials, because the resistances of different metal thin strip materials and thicknesses, different high-resistance layer materials and thicknesses are different; the full cable is then threaded into the metal armor 4 so that the high temperature superconducting conductor has good self-support and a pressure vessel to provide coolant.

As shown in fig. 2, the sub-cable central skeleton 5 of the high-temperature superconducting sub-cable 2 is formed by metal strands through multi-stage stranding, the alternating current loss can be controlled by selecting different stranding torques and adjusting the high-resistance layer material and the thickness of the surface of the metal strands by an electroplating process, the metal cables can also be used as a stable matrix, gaps among the metal cables can also be used as channels of a coolant, and the porosity among the metal strands can be adjusted by selecting the metal strands with different diameters and the stranding torques. The sub-cable central skeleton wrapping 6 adopts a metal belt, such as: a stainless steel belt or a copper belt plated with a high-resistance layer material and the like are wound on the sub-cable central skeleton 5, so that the surface of the sub-cable central skeleton 5 can be smoothed, and the damage or strain to a high-temperature superconducting strip can be avoided or reduced; then, winding a plurality of layers of high-temperature superconducting tapes 7 on the sub-cable central skeleton wrap 6, and increasing the number of the tapes to enhance the current carrying capacity of the conductor; and then, winding the sub-cables 8 on the multi-layer high-temperature superconducting tape 7, and controlling the resistance among the sub-cables by selecting different metal thin strip materials and thicknesses and selecting different coating materials and thicknesses. The metal belt refers to a stainless steel belt or a copper belt and the like adopted by various wrapping layers; the coating material and the thickness thereof refer to a high-resistance layer material coated on the surface of the wrapping strip or the metal strand through an electroplating process, such as: nickel, chromium or tin, the thickness of which can be controlled by the electroplating process.

The foregoing is merely exemplary and illustrative of the present invention and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the scope of the invention as defined in the following claims.

Claims (4)

1. A large-current high-temperature superconducting conductor based on a center skeleton of a stranded cable structure is characterized in that: the cable comprises a full-cable central framework (1), a plurality of high-temperature superconducting sub-cables (2) wound on the full-cable central framework (1), a full-cable protective wrapping (3) wrapped on the outer sides of the plurality of high-temperature superconducting sub-cables (2) and a metal armor (4); the central skeleton (1) of the whole cable is a metal cable made of multi-stage stranded cables, a spiral pipe wound by stainless steel bands, a perforated stainless steel pipe or a perforated copper pipe, and the surface of a folded yarn in the metal cable is plated with a high-resistance layer material; the high-temperature superconducting sub-cables (2) are composed of a sub-cable central framework (5), a sub-cable central framework wrapping (6), a plurality of layers of high-temperature superconducting strips (7) and sub-cable wrapping (8); the sub-cable central skeleton (5) is made of metal strand wires through multi-stage stranding, and the surfaces of the metal strand wires are plated with high-resistance layer materials; the sub-cable central framework wrapping (6) is wound on the sub-cable central framework (5) by adopting a metal belt; the multilayer high-temperature superconducting tape (7) is wound on the outer side of the sub-cable central framework wrapping (6); the sub-cable wrapping (8) is a metal belt and wraps the outer side of the multilayer high-temperature superconducting tape (7).

2. The large-current high-temperature superconducting conductor based on the central framework of the stranded cable structure according to claim 1, wherein: after the plurality of high-temperature superconducting sub-cables (2) are wound on the full-cable central framework (1) through stranded cables, full-cable protective wrapping (3) is applied to the outermost layer of the full-cable central framework, and then the full-cable protective wrapping penetrates into the metal armor (4).

3. The large-current high-temperature superconducting conductor based on the central framework of the stranded cable structure according to claim 1, wherein: the high-resistance layer is made of nickel, chromium or tin.

4. The large-current high-temperature superconducting conductor based on the central framework of the stranded cable structure according to claim 1, wherein: the metal belt wrapped by the sub-cable is a stainless steel belt or a copper belt, the copper belt is plated with a high-resistance layer material, and the high-resistance layer material is nickel, chromium or tin.

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