Superconductive cable

Abstract

To provide a superconductive cable excellent in insulation property of at least each conductor.SOLUTION: A multi-core structure superconducting cable includes a plurality of conductors 10, at least one first tube 20, and a second tube 30 that houses the first tube 20. At least one of the plurality of conductors 10 among the plurality of conductors 10 is housed individually in the first tube 20, while the remaining conductors 10 are housed in the second tube 30 in an insulated state from each other. This configuration ensures insulation between the conductors 10 while allowing the coolant to come into direct contact with each conductor 10, thereby enabling higher current-carrying performance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a superconducting cable having a multi-core structure containing a plurality of conductors. [Background technology]

[0002] Previously, superconducting cables have been known that use superconducting wires that become superconducting at cryogenic temperatures as conductors and can transmit large currents with low loss. For example, in the propulsion systems of aircraft and other flying objects, where electrification is being considered to reduce CO2 emissions, there is a growing need for lightweight, highly efficient, and high-output superconducting technology. To realize such propulsion systems, development is underway on superconducting cables capable of carrying large currents that are suitable for supplying power to electric motors that will replace jet engines.

[0003] In Patent Document 1 below, the applicant has developed a superconducting cable with a multi-core structure in which insulating spacers are inserted inside a thermal insulation pipe to insulate a plurality of cable cores from one another. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7383839 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a means for ensuring the insulation of each conductor in a superconducting cable containing a plurality of conductors, using a method different from the structure disclosed in Patent Document 1. [Means for solving the problem]

[0006] The present invention, which has been made to solve the above-mentioned problems, is a superconducting cable with a multi-core structure, which has at least a plurality of conductors, at least one first tube, and a second tube that houses the first tube, and is configured so that at least one of the plurality of conductors is housed in each of the first tubes, and the remaining conductors are housed in the second tube while being insulated from each other. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a superconducting cable in which each conductor has excellent insulation properties. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic end view of a superconducting cable according to a first embodiment. [Figure 2] 1 is a schematic end view showing a current-carrying state of a superconducting cable according to Example 1. FIG. [Figure 3] FIG. 6 is a schematic end view of a superconducting cable according to a second embodiment. [Figure 4] FIG. 10 is a schematic end view of a superconducting cable according to a third embodiment. [Figure 5] FIG. 10 is a schematic end view of a superconducting cable according to a fourth embodiment. [Figure 6] FIG. 10 is a schematic end view of a superconducting cable according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0010] <1> Overall configuration (Fig. 1) FIG. 1 is a schematic end view showing the internal structure of a superconducting cable according to Example 1 when the cable is cut perpendicular to the axial direction of the cable. The superconducting cable (hereinafter simply referred to as the “cable”) according to this embodiment includes a conductor 10, a first tube 20, a second tube 30, and a third tube . Each part will be described in detail below.

[0011] <2> Conductor (Figure 1) The conductor 10 is a member for passing a current through the cable in a superconducting state. In this embodiment, three conductors 10 are provided within the cable.

[0012] <2.1> Conductor configuration examples In the present invention, the configuration of the conductor 10 is not particularly limited, and various configurations can be adopted. For example, a laminate of multiple tape-shaped superconducting wires can be used as the conductor 10 of the present invention. Here, "tape-shaped" means that the shape is long and flat, and the planar dimensions are sufficiently large compared to the thickness. According to the conductor 10 having this configuration, the cross-sectional area of ​​the conductor 10 in the axial direction can be significantly reduced.

[0013] <2.2> Adding insulation to conductors In the present invention, there is no particular limitation as to whether or not an insulating portion is provided on the outer periphery of the conductor 10. However, when the insulation between the conductors 10 is ensured by the first tube 20, as in this embodiment (FIG. 1), it is desirable not to provide a separate insulating portion on the outer periphery of each conductor 10. Since the insulating portion can be an interference factor when the superconducting wire that makes up the conductor 10 is cooled with a refrigerant, by having the conductor 10 come into direct contact with the refrigerant without providing an insulating portion, it also contributes to improving the cooling efficiency.

[0014] <2.3> Conductor layout In the present invention, the posture and arrangement of each conductor 10 are not particularly limited, and various modes can be adopted.

[0015] <3> First tube (Figure 1) The first tube 20 is a member for insulating the conductors 10 from each other. The inside of the first pipe 20 also functions as a flow path (first flow path 21) for flowing a refrigerant such as liquid nitrogen. In this embodiment, three first tubes 20 are provided, each housing one conductor 10 .

[0016] <3.1> Example of the first tube configuration In the present invention, the configuration of the first tube 20 is not particularly limited, and various materials and shapes can be used. The first pipe 20 is preferably resistant to temperatures of -50°C or lower, and is preferably flexible and elastic at extremely low temperatures where a refrigerant is used. Examples of materials that satisfy the desired properties of the first tube 20 include fluororesin, polyethylene resin, polyphenylsulfone resin, and glass fiber reinforced resin. Alternatively, the resin material that constitutes the first tube 20 may be a rubber substitute material such as polyolefin resin.

[0017] <4> Second tube (Figure 1) The second pipe 30 is a member that is separate from the first pipe 20 and that defines a flow path (second flow path 31) for flowing a coolant such as liquid nitrogen. In this embodiment, three first pipes 20 are housed inside the second pipe 30, and the second flow passage 31 is provided in a manner completely separated from the three first flow passages 21.

[0018] <4.1> Example of second tube configuration In the present invention, the configuration of the second tube 30 is not particularly limited, and various materials and shapes can be used. Like the first pipe 20, the second pipe 30 preferably has a cold resistance temperature of -50°C or lower, and is preferably flexible and elastic at extremely low temperatures where a refrigerant is used. In the present invention, the second tube 30 may be made of the same material as the first tube 20, or may be made of a different material.

[0019] <5> Third tube (Figure 1) The third tube 40 is a member for preventing heat from entering the superconducting cable from the outside. In this embodiment, the second pipe 30 is housed inside the third pipe 40, and the space 41 between the second pipe 30 and the third pipe 40 is evacuated to form an insulating space.

[0020] <5.1> Example of the third tube configuration In the present invention, the configuration of the third tube 40 is not particularly limited, and various materials and shapes can be used. The third pipe 40, like the first pipe 20 and the second pipe 30, preferably has a cold resistance temperature of -50°C or lower, and is preferably flexible and elastic at extremely low temperatures where a refrigerant is used. In the present invention, the third tube 40 may be made of the same material as the first tube 20 and the second tube 30, or may be made of a different material.

[0021] <5.2> Adding heat insulation The third pipe 40 may further be provided with a heat insulating portion (not shown) made of a material that has heat insulating properties at the extremely low temperatures at which the refrigerant is used. The heat insulating portion can be formed by wrapping a heat insulating sheet around the outer periphery of the third pipe 40 or by spraying a heat insulating material made of a urethane resin composition or the like onto the outer periphery of the third pipe 40 .

[0022] <6> Usage image (Figure 2) With reference to FIG. 2, the state of use of the superconducting cable according to this embodiment will be described. FIG. 2 shows a state in which a refrigerant flows through first flow path 21 and second flow path 31 when current is applied to the superconducting cable. The conductors 10 are reliably insulated from one another by the first tubes 20 and are directly cooled by the refrigerant flowing within the first tubes 20 .

[0023] <7> summary As described above, according to the configuration of this embodiment, by ensuring the insulation between the conductors while bringing the refrigerant into direct contact with each conductor, it is possible to ensure a higher current carrying capacity. [Example]

[0024] Second Embodiment A superconducting cable according to a second embodiment of the present invention will be described with reference to FIG.

[0025] <1> Overall structure In the superconducting cable of Example 1, the number of first tubes 20 was the same as the number of conductors 10, whereas in the superconducting cable of this example, of the three conductors 10 (10a to 10c), two conductors 10a and 10b are housed in first tubes 20, and the remaining conductor 10c is not housed in a first tube 20 but is housed in a second tube 30.

[0026] <2> summary In the configuration according to this embodiment, the refrigerant can be brought into direct contact with each conductor while ensuring the insulation of each conductor. Furthermore, compared to the configuration of Example 1, the number of first tubes can be reduced, which contributes to reducing the weight of the entire cable. [Example]

[0027] A superconducting cable according to a third embodiment of the present invention will be described with reference to FIG.

[0028] <1> Overall structure The superconducting cable of this embodiment is configured such that of the four conductors 10 (10a to 10d), two conductors 10a and 10b are insulated from each other by a spacer 50 separately installed inside the second tube 30, and of the remaining two conductors 10c and 10d, one conductor 10c is housed in the first tube 20, and the other conductor 10d is housed in the second tube 30 without being housed in the first tube 20.

[0029] <2> Spacer In the present invention, the spacer 50, like the first pipe 20, is preferably resistant to temperatures of -50°C or lower, and is preferably flexible and elastic at extremely low temperatures using a refrigerant. Furthermore, in the present invention, there is no particular limitation on whether the spacer 50 is in contact with the second tube 30. As shown in Fig. 4, a slight gap may be provided between the end of the spacer 50 and the inner wall of the second tube 30, or the spacer 50 may be configured to abut against the inner wall of the second tube 30. When the spacer 50 abuts against the inner wall of the second tube 30, the second flow path 31 is divided into three flow paths, and the refrigerant can be circulated through each of the divided flow paths. These configurations may be designed as appropriate, taking into account factors such as the flexibility required for the entire cable.

[0030] <3> summary In the configuration according to this embodiment, the refrigerant can be brought into direct contact with each conductor while ensuring the insulation of each conductor. [Example]

[0031] A superconducting cable according to a fourth embodiment of the present invention will be described with reference to FIG.

[0032] <1> Overall structure The superconducting cable of this embodiment has three conductors 10 (10a to 10c), of which the first conductor 10a is housed in a first tube 20, the second conductor 10b has an insulating portion 11 on its outer periphery, and the third conductor 10c is not housed in the first tube 20 and is housed in a second tube 30 without having an insulating portion 11 on its outer periphery.

[0033] <2> Insulation In the present invention, the insulating portion 11 can be made of a material that is insulating, heat-resistant, and voltage-resistant, and can be formed by wrapping, for example, a strip-shaped sheet made of paper or polyimide around the conductor 10.

[0034] <3> summary In the configuration of this embodiment, although a decrease in the current-carrying performance of conductors with insulating sections is expected due to a decrease in cooling efficiency, it is advantageous in that when there are constraints on the weight or size of the superconducting cable, there is room for design changes such as reducing the weight of the entire cable or reducing the diameter of each tube by, for example, reducing the number of first tubes as much as possible. [Example]

[0035] A superconducting cable according to a fifth embodiment of the present invention will be described with reference to FIG.

[0036] <1> Overall structure The superconducting cable according to this embodiment has the same configuration as that of the first embodiment except that the third pipe 40 is removed and a heat insulating portion 60 is provided on the outer periphery of the second pipe 30 . As explained in <5.2> above, the heat insulating portion 60 can be made of a material that has heat insulating properties at the extremely low temperatures at which the refrigerant is used.

[0037] <2> summary In the configuration according to this embodiment, the refrigerant can be brought into direct contact with each conductor while ensuring the insulation of each conductor.

[0038] Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the specific embodiments described above. Various modifications and changes to the specific examples described in the above embodiments are possible within the scope of the gist of the present invention as defined in the claims. [Industrial Applicability]

[0039] The superconducting cable of the present invention can be suitably used as a power transmission cable or a power supply cable. [Explanation of symbols]

[0040] 10: conductor 11: Insulation section 20: First tube 21: First Channel 30: Second tube 31: Second Channel 40: Third tube 41: Space 50: Spacer 60: Insulation section

Claims

1. A superconducting cable having a multi-core structure, A plurality of conductors; at least one first tube; a second tube that houses the first tube; and Among the plurality of conductors, At least one of the conductors is accommodated in each of the first tubes, The remaining conductors are housed in the second tube in a state insulated from each other. Superconducting cable.

2. No insulating layer is provided around each of the plurality of conductors. The superconducting cable according to claim 1.

3. the number of the first tubes is equal to the number of the plurality of conductors, The plurality of conductors are housed in the first tube one by one.

3. The superconducting cable according to claim 2.

4. a third tube that accommodates the second tube; a vacuum-state heat insulating space is formed between the second pipe and the third pipe, The superconducting cable according to claim 3.

5. A heat insulating portion is provided on the outer periphery of the second pipe. The superconducting cable according to claim 1.

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