Terminal connection portion for superconducting cable

Abstract

To provide means that can prevent damage to each member that is caused by differences in thermal contraction between the members that make up a terminal connection portion.SOLUTION: A terminal connection portion is for connecting a superconducting cable and includes at least an inner accommodating portion 10, an outer accommodating portion 20, and an extension tube 30. A return path for the refrigerant is provided inside the inner accommodating portion 10, and the extension tube 30 connects the inner accommodating portion 10 and the outer accommodating portion 20, and by expanding and contracting in accordance with the relative movement of the inner accommodating portion 10 with respect to the outer accommodating portion 20, stress on the components, particularly the outer accommodating portion 20, caused by thermal contraction of the inner accommodating portion 10 is prevented.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a termination for a superconducting cable. [Background technology]

[0002] As a terminal connection part of a superconducting cable, a structure is known which has an inner housing tube part (211) that houses the cable core (11) of the superconducting cable (10) and an outer housing tube part (221) that surrounds this inner housing tube part (211) (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-9093 Summary of the Invention [Problem to be solved by the invention]

[0004] The inner accommodating pipe portion (211) according to Patent Document 1 is cooled by the passage of a refrigerant flowing through the superconducting cable, and therefore undergoes thermal contraction. On the other hand, the outer accommodating pipe portion (221) does not undergo thermal contraction because it is in contact with the outside environment at room temperature. As a result, stress due to the thermal contraction of the inner casing tube is generated in each component (for example, the outer casing tube) connected to the inner casing tube, which may cause damage to each component.

[0005] Therefore, one of the objects of the present invention is to provide a means capable of preventing damage to each member that constitutes a termination joint for a superconducting cable due to differences in thermal contraction between the members. [Means for solving the problem]

[0006] The present invention, which has been made to solve the above-mentioned problems, is a termination connection part for connecting a superconducting cable, comprising at least an inner accommodating part, an outer accommodating part, and an expandable tube, wherein a return path for a refrigerant is provided inside the inner accommodating part, and the expandable tube connects the inner accommodating part and the outer accommodating part, and expands and contracts in accordance with the relative movement of the inner accommodating part with respect to the outer accommodating part. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent damage to the components that constitute the termination joint for a superconducting cable due to differences in thermal contraction between the components. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing the internal structure of a terminal connection part for a superconducting cable according to the present invention. [Figure 2] FIG. 10 is a schematic diagram showing the operation of the telescopic tube. [Figure 3] 5A and 5B are schematic diagrams showing the operation of the drawing tube. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] <1> Overview (Figure 1) FIG. 1 is a schematic diagram showing the internal structure of a terminal connection part A for a superconducting cable according to the present invention. The termination connection part A in this embodiment is a device for connecting a superconducting cable and connecting it to a power source, which is the source of power, and various devices, which are the destinations of power, via power leads, to pass electricity between them.

[0011] <1.1> Superconducting cable A superconducting cable is a component that carries electricity by means of a conductor housed inside. In the present invention, the superconducting cable is configured to have at least one flow path for flowing a coolant for cooling the conductor. Furthermore, in the present invention, when two or more refrigerant flow paths are provided, the tubes constituting these flow paths may have a structure in which one tube is housed within the other tube (multiple tube structure), or may have a structure in which the tubes exist independently of each other within the superconducting cable (independent tube structure). In this embodiment, a forward path (a flow path for sending the refrigerant) and a return path (a flow path for returning the refrigerant) for the refrigerant are separately provided within the superconducting cable, and of these, the forward path is connected to the flow path pipe 40 housed in the inner accommodating section 10, and the return path is connected to the space between the inner accommodating section 10 and the flow path pipe 40 (outer space 50). In the present invention, the outward and return paths may be reversed.

[0012] <1.2> Overall structure (Fig. 1) The superconducting cable termination A according to this embodiment comprises an inner accommodating section 10, an outer accommodating section 20, an expandable tube 30, a flow path pipe 40, and the like. The following describes the underlying configuration and details of each part.

[0013] <2> Flow pipe (Figure 1) The flow path pipe 40 is a pipe that communicates with a coolant flow path provided in the superconducting cable, and allows the coolant to flow within the terminal connection part A, while also allowing the coolant to flow outside the flow path pipe 40 as necessary. In the present invention, the flow path pipe 40 may be formed by drawing out a member that constitutes a flow path within the superconducting cable as it is, or may be formed by a member separate from the member that constitutes the flow path. In this embodiment, the flow path pipe 40 is connected to the outgoing path of the coolant provided in the superconducting cable.

[0014] <3> Inner storage compartment (Figure 1) The inner accommodating portion 10 is a member for providing a return path for the refrigerant therein. In the present invention, the shape of the inner accommodating portion 10 is not particularly limited. In this embodiment, the inner storage section 10 is configured by providing an inner partition wall 11, a tip tube 12, a drawer tube 13, and an inner lid 14.

[0015] <3.1> Internal partition (Fig. 1) The inner partition wall 11 is a member for connecting one end of the telescopic tube 30, which will be described later. In the present invention, the shape of the inner partition wall 11 is not particularly limited. In this embodiment, the inner partition wall 11 is appropriately formed with a hole (insertion hole 111) for inserting the flow path pipe 40 and a hole (communication hole 112) for connecting the outer space 50 with the internal space of the tip tube 12.

[0016] <3.2> Tip tube (Fig. 1) The tip tube 12 is a member that constitutes part of the flow path of the refrigerant in the terminal connection part A. In the present invention, the shape of the tip tube 12 is not particularly limited. In this embodiment, one end of the tip tube 12 is fixed to the inner partition wall 11, and an inner lid 14 is configured to be freely attached and detached to the other end of the tip tube 12, and the space between the tip tube 12 and the withdrawal tube 13 serves as a return path for the refrigerant.

[0017] <3.3> Drawer tube (Fig. 1) The pull-out tube 13 forms part of the refrigerant flow path in the terminal connection part A, and is a component that is located inside the tip tube 12 during the assembly process of the terminal connection part A and is used to pull out the mounting point of the seal part 15, which is provided midway through the refrigerant flow path, to the outside of the outer accommodating part 20. In the present invention, the shape, structure, number of the draw-out tubes 13, etc. are not particularly limited. In this embodiment, the withdrawal tube 13 is made of a bellows (accordion tube), and one end of the withdrawal tube 13 is connected to the flow path pipe 40 extending from the inner storage section 10, and a seal mounting section 131 (described later) is provided on the other end, so that the internal space of the withdrawal tube 13 serves as the outward path for the refrigerant.

[0018] <3.4> Inner lid (Fig. 1) The inner lid 14 is a member for separating the interior of the inner storage portion 10 from a vacuum space 60 formed by the outer lid 23, which will be described later. In this embodiment, the inner lid 14 is connected to the open end side of the tip tube 12 . The inner lid 14 is provided with a discharge hole 141a through which the refrigerant flowing through the flow path pipe 40 can be discharged, and a discharge hole 141b through which the refrigerant flowing through the outer space can be discharged.

[0019] <4> Outer housing (Fig. 1) The outer accommodating portion 20 is a member that constitutes the outer shell of the terminal connection portion A. In the present invention, the shape of the outer accommodating section 20 is not particularly limited. In this embodiment, the outer storage section 20 includes a heat insulating section 21, an outer wall 22, and an outer lid 23.

[0020] <4.1> Insulation section (Fig. 1) The heat insulating portion 21 is a member for suppressing heat penetration from the outside of the outer accommodating portion 20 into the inside of the inner accommodating portion 10 . In the present invention, the shape, material, arrangement, etc. of the heat insulating portion 21 are not particularly limited. In this embodiment, a heat insulating material is disposed inside the cylindrical main body of the outer accommodating section 20 to form a heat insulating section 21 .

[0021] <4.2> Exterior wall (Fig. 1) The outer wall 22 is a member that constitutes the end portion of the outer storage section 20. In the present invention, the shape of the outer wall 22 is not particularly limited. In this embodiment, an accommodation hole 221 is provided in the approximate center of the outer wall 22 arranged at the end of the outer accommodation section 20, and the tip tube 12 and the telescopic tube 30 can be accommodated inside through this accommodation hole 221. Furthermore, the end of the telescopic tube 30 is fixed to the inner wall side of the outer wall 22.

[0022] <4.3> Outer lid (Fig. 1) The outer lid 23 is a member for making the space closed by the outer lid 23 into a vacuum space 60 . In the present invention, the shape of the outer lid 23 is not particularly limited. In this embodiment, the outer lid 23 is fixed to the outer surface of the outer wall 22, and the internal space partitioned by the outer lid 23 is evacuated with a vacuum pump or the like to create a vacuum state. Furthermore, since the internal space of the outer lid 23 is also connected to the space between the tip tube 12 and the telescopic tube 30, a vacuum space 60 is formed in the space surrounding the internal space of the tip tube 12, where the refrigerant flows, i.e., the space between the tip tube 12 and the telescopic tube 30.

[0023] <5> Telescopic tube (Figure 1) The telescopic tube 30 is a member for absorbing stress that occurs in the outer accommodating section 20 due to thermal contraction of the inner accommodating section 10 . In the present invention, the shape, structure, number of the telescopic tubes 30, etc. are not particularly limited. In this embodiment, a part of the telescopic tube 30 is made of a bellows (bellows tube), and the telescopic tube 30 connects between the inner partition wall 11 and the outer wall 22 .

[0024] <6> Operational image (Fig. 2, Fig. 3) Next, the internal operation of the termination connection part A according to the present invention will be described with reference to FIGS.

[0025] <6.1> Operation of the telescopic tube (Fig. 2) When the superconducting system is in operation, the inner accommodating section 10 is cooled by the refrigerant forward path A1 and the refrigerant return path A2 and undergoes thermal contraction, while the outer accommodating section 20 is in contact with the outside of the terminal connection section A, resulting in a difference in thermal contraction between the two. As a result, the internal partition wall 11 of the internal storage section 10 moves toward the right side of the paper in Figure 2 relative to the external wall 22 of the external storage section 20 due to stress generated by the difference in thermal contraction, acting in the direction of widening the gap between the external wall 22 and the internal partition wall 11. At this time, the telescopic tube 30 connecting the outer wall 22 and the inner partition 11 expands in response to the movement of the inner partition 11 (for example, the telescopic tube 30 becomes extended as shown in Figure 2), thereby suppressing the occurrence of tensile stress on the outer wall 22.

[0026] <6.2> Operation of the drawer (Fig. 3) In the process of assembling the terminal connection part A of the present invention, while the inner accommodating part 10 and the outer accommodating part 20 are appropriately assembled, a seal part 15 is attached to the end of the draw-out tube 13 opposite to the end on the side connected to the flow path pipe 40, in order to seal the refrigerant outgoing path A1 inside the draw-out tube 13 from the outside of the tube. In order to improve the efficiency of this attachment work, it may be desirable to pull out the attachment portion (seal attachment portion 131) of the seal portion 15 to the outside of the outer accommodating portion 20. At this time, by pinching the seal mounting portion 131 and pulling it to the left side of the paper surface of FIG. 3, the drawable tube 13 is extended, and the seal mounting portion 131 can be drawn out and exposed to the outside of the outer accommodating portion 20.

[0027] <7> summary As described above, the structure according to this embodiment provides the following advantageous effects. (1) The telescopic tube 30 absorbs changes in the distance between the outer accommodating section 20 and the inner accommodating section 10, thereby suppressing stress on the outer accommodating section 20 caused by thermal contraction of the inner accommodating section 10. This effect is not limited to the outer accommodating section 20, but also applies to other components directly or indirectly connected to the inner accommodating section 10. (2) The seal attachment portion 131 located midway along the refrigerant flow path can be drawn out of the outer accommodating portion 20 by extending the drawing tube 13, which improves the efficiency of the assembly work of the terminal connection portion A.

[0028] This technology prevents damage to the components of a superconducting cable termination due to differences in thermal contraction between them, thereby enabling the provision of a superconducting cable termination with stable performance that contributes to a decarbonized society. This will contribute to Goal 7 of the Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy for all" and Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," which are international goals aimed at achieving a sustainable and better world by 2030 as outlined in the 2030 Agenda for Sustainable Development adopted at the United Nations Summit in September 2015.

[0029] 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. [Explanation of symbols]

[0030] A: Termination connection part A1: Refrigerant outbound A2: Refrigerant return line 10: Inner storage section 11: Internal septum 111: Insertion hole 112:Communication hole 12:Tip tube 13: Pull-out tube 131: Seal mounting part 14: Inner lid 141a, 141b: Discharge hole 15: Seal part 20: Outer storage section 21: Insulation section 22: Exterior wall 221: Storage hole 23: Outer lid 30: Telescopic tube 40: Flow pipe 50:Outside space 60: Vacuum space

Claims

1. A terminal connection part for connecting a superconducting cable, The device includes at least an inner storage section, an outer storage section, and a telescopic tube, A return path for the refrigerant is provided inside the inner accommodating portion, The telescopic tube connects the inner storage section and the outer storage section, and is configured to extend and retract in accordance with the relative movement of the inner storage section with respect to the outer storage section. Termination joint for superconducting cable.

2. The inner storage portion is a tip tube located inside the telescopic tube; a withdrawal tube located inside the tip tube and extendable in a tube axial direction; and the space between the telescopic tube and the tip tube is a vacuum space, The interior of the drawing cylinder is one of two flow paths for the refrigerant to go in and out, a space between the tip tube and the drawing tube is used as the other flow path of the refrigerant going in and out, One end of the pull-out tube is directly or indirectly connected to the inner storage section.

2. The terminal connection for a superconducting cable according to claim 1.

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