JPH0714620A - Structure of current supply terminal for oxide superconductor - Google Patents

Abstract

PURPOSE:To provide the structure of a current supply terminal of an oxide superconductor which gives less strain to a superconductive tape unit than existing structure which fixes individual superconductive tape unit on the outer ciecumference surface, is resistant to apply strain to the current supply terminal, and has low deterioration in superconductive performance. CONSTITUTION:Plural spiral grooves 12 are formed on the outer circumference surface of a tube made of metal, and a coolant flow path is formed on the inside of the tube to form a central tube 11. An oxide superconductive tape unit 15 is loosely inserted without fixing into each spiral groove of the central tube 11 to fabricate a superconductor 9. At least one end of the superconductor 9, a flexible current supply lead wire 30 is connected to the superconductive tape unit 15 inside the spiral groove, and the superconductive tape unit 15 in the connected part is made movable together with the lead wire along the spiral groove 12 of the central tube 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a current supply terminal of an oxide superconducting conductor, which is being applied and developed for transporting electric power or for a superconducting magnet.

[0002]

2. Description of the Related Art Conventionally, an attempt has been made to manufacture an electric power cable for electric power transportation, a superconducting magnet or a superconducting power cable for a field winding of a superconducting generator by using an oxide superconducting conductor having a high critical temperature. There is. As a conventional example of such a superconducting conductor, as shown in FIG.
A plurality of long oxide-based superconducting tape units 1 (see FIG.
There is known a superconducting conductor 3 in which 16 pieces in the example of 0) are fixed by soldering so that they are spirally arranged adjacent to each other around a pipe 2 made of copper or the like. The superconducting tape unit 1 of the superconducting conductor 3 has a sectional structure as shown in FIG.
A plurality of superconducting tapes 6 formed by covering the oxide superconducting core 4 with a soft metal sheath 5 made of silver or the like are integrally laminated with a metal adhesive such as solder. Figure 1
In the superconducting conductor 3 having the structure shown in FIG. 0, liquid nitrogen is made to flow inside the central pipe 2 as a refrigerant, and this liquid nitrogen cools the surrounding oxide superconducting core 4.

[0003]

Conventionally, in order to manufacture the superconducting conductor 3 having the structure shown in FIG. 10, one superconducting tape unit 1 is constructed by laminating a plurality of superconducting tapes 6,
A method is used in which a plurality of superconducting tape units 1 are prepared, each is spirally wound around the outer peripheral surface of the pipe 2, and then fixed by soldering. However, when the superconducting conductor 3 is manufactured by this method, since the superconducting tape unit 1 is wound while being bent directly, the individual superconducting tapes 6 are likely to be distorted, and the superconducting tape 6 is locally wound on the superconducting tape 6 depending on the winding method. There is a problem that it is easy to add large distortion. That is, the oxide superconducting core 4 is made of Bi ₂ S.
r ₂ Ca ₂ Cu ₃ O _x , Bi ₂ Sr ₂ Ca ₁ Cu ² O _y , Bi _{1.6
Pb 0.4 Sr 2 Ca 2 Cu 3} O x, Tl 2 Ba 2 Ca 2 Cu
³ O ^y , Tl ² Ba ² Ca ¹ Cu ² O ^y , or Y ₁ Ba ₂
Since it is a ceramic having a composition represented by Cu ₃ O _x , it has brittleness as a ceramic and has a problem that it is very weak against bending force and tensile force. Further, since the sheath 5 made of silver is very soft, there is a problem that the oxide superconducting core 4 is easily damaged even by a small external force.

Next, the plurality of superconducting tape units 1
When they are sequentially wound around the pipe 2 and fixed one by one by soldering, the solder which has already fixed the superconducting tape 6 which has already been soldered is re-melted by the heat when the other superconducting tape 6 is soldered, and the solder is already soldered. The attached superconducting tape 6 may be peeled off. In addition, when sequentially fixing a plurality of superconducting tape units 1 by soldering, it is difficult to fix the entire superconducting tape units 1 at the correct positions at the same time.

Further, in order to connect the current supply line to the superconducting conductor 3 having the structure shown in FIG. 10, conductive current supplying rings are fitted at both ends of the superconducting conductor 3 and fixed by soldering. However, in this case, when the superconducting tape unit 1 is fixed to the pipe 2 by soldering, the end portions of the respective superconducting tape units 1 are fixed at both ends of the superconducting conductor 3, so that the operation is performed at the time of fixing the solder. Due to the difference in the coefficient of thermal expansion between the pipe 2, the superconducting tape unit 1 and the current supply ring in the heating process and the process of cooling to room temperature, thermal strain acts on these joints, and the superconducting tape unit May cause unnecessary distortion. Further, when an external force such as bending is applied when the superconducting conductor 3 is laid, the superconducting conductor 3 tends to be uniformly deformed as a whole, so that strain may be added to the superconducting tape unit 1 and the superconducting characteristics may be deteriorated. It was

The present invention has been made in view of the above circumstances and does not give distortion to the superconducting tape unit as compared with the conventional structure in which each superconducting tape unit is fixed to the outer peripheral surface of the tubular body, and An object of the present invention is to provide a structure of a current supply terminal of an oxide superconducting conductor which has a structure in which strain does not easily act on a current supply terminal portion and has little deterioration of superconducting characteristics.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is such that a plurality of spiral grooves are formed on the outer peripheral surface of a tubular body made of a metal material and a forward path of the refrigerant is formed inside. A central tube body is formed, and an oxide superconducting tape unit is loosely inserted in each spiral groove of the central tube body in a non-fixed state to form a superconducting conductor, and at least one end of the superconducting conductor is bent. A lead wire for freely supplying an electric current is connected to the superconducting tape unit in the spiral groove, and the superconducting tape unit at the connecting portion is movable along with the lead wire along the spiral groove of the central tube.

In order to solve the above-mentioned problems, the present invention provides a central tube body in which a plurality of spiral grooves are formed on the outer peripheral surface of a tube body made of a metal material and a forward path of the refrigerant is formed inside. An oxide superconducting tape unit is loosely inserted into each spiral groove of the central tube body in a non-fixed state to form a superconducting conductor, and a conductive cylindrical member is externally attached to one end of the superconducting conductor in the longitudinal direction. The tubular member is fixed to the superconducting conductor in the spiral groove with a conductive adhesive, and a lead wire for current supply is connected to the tubular member, while the other end portion in the longitudinal direction of the superconducting conductor is connected. , The flexible lead wire for current supply is branched into multiple parts, and each branch line is individually connected to the superconducting tape unit, and the superconducting tape unit at the connecting portion moves along with the branch line along the spiral groove of the central pipe body. It is made free

In order to solve the above-mentioned problems, the superconducting tape unit according to claim 1 or 2 is provided with an oxide superconducting core inside a tape-shaped sheath made of a conductive metal material. A plurality of such superconducting tapes are laminated and fixed to each other.

[0010]

[Function] Since the superconducting tape unit is housed in the spiral groove of the central tube and the superconducting tape unit is spirally wound around the central tube, it is possible to flow a refrigerant such as liquid nitrogen into the central tube. The superconducting tape unit can be cooled and the oxide superconducting core of the superconducting tape unit can be put into a superconducting state and used for conducting electricity. Furthermore, 1
Since a plurality of superconducting tape units are provided for the central tube of the book, the current capacity becomes large.

Since the superconducting tape unit is loosely inserted in the spiral groove on the outer surface of the central tube body in a non-fixed state, the superconducting tape unit is independent in the spiral groove even when an external force such as bending or twisting acts on the superconducting conductor. Therefore, the external force is less likely to directly act on the superconducting tape unit. Therefore, even when an external force acts on the superconducting conductor, the superconducting tape unit is not damaged and the superconducting characteristics are not deteriorated. Also, even if bending force or twisting is applied to the superconducting power cable during installation, etc., the superconducting tape unit can move slightly displaced in the spiral groove of the central tube body, so stress or strain is applied to a part of the superconducting tape unit. Never concentrate. Furthermore, since the superconducting tape units are individually connected to the flexible current lead wires so as to be movable, even if external force such as bending acts on the superconducting conductors, each superconducting tape unit can be moved to the central tube body. It is possible to maintain the above-described action of being able to move, so that strain is unlikely to act on the superconducting tape unit.

Further, since the superconducting tape unit is completely installed by inserting the superconducting tape unit into the spiral groove of the central tube body, the fixing portion such as the soldering portion to which the superconducting tapes of the superconducting tape unit are fixed is remelted. There is no fear of causing it.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a structure of a current supply terminal of an oxide superconducting conductor according to the present invention. FIG. 1 (a) shows a structure on one end side of an oxide superconducting conductor 9, and FIGS. ) Indicates the structure on the other end side. 2 and 3 are for explaining the internal structure of the oxide superconducting conductor 9. The oxide superconducting conductor 9 is incorporated in the superconducting power cable 10 having the sectional structure shown in FIG. The oxide superconducting conductor 9 has a central tube body 11 shown enlarged in FIGS. 2 and 3, and the central tube body 11 is provided on the outer periphery of the tube body made of a highly conductive metal material such as copper or aluminum. A plurality of spiral grooves 12 (10 in this embodiment) are formed,
The internal space of the tubular body is used as a refrigerant outward path 13, and a refrigerant such as liquid nitrogen is allowed to flow through the refrigerant outward path 13. In the central pipe body 11 shown in FIG. 3, the spiral pitch of the spiral groove 12 is described as short, but the spiral pitch can be freely increased to several tens of cm to several m.

Inside the spiral groove 12 of the central tube 9,
The superconducting tape unit 15 is loosely inserted so as not to protrude from the spiral groove 12 with some play as shown in FIG. This is to prevent the mechanical force from acting on the superconducting tape unit 15 when another member is wound around or attached to the outside of the central tube body 9. As shown in FIG. 2, the superconducting tape unit 15 is formed by laminating a plurality of superconducting tapes 16 and fixing them to each other with a metal adhesive such as solder.
The superconducting tape 16 is made of Y-Ba-Cu-O system, Bi-P.
b-Sr-Ca-Cu-O system, Tl-Ba-Ca-Cu-O system,
A tape-shaped superconducting core 17 made of an oxide superconductor represented by, for example, is covered with a sheath 18 made of a noble metal such as silver.

Here, the superconducting tape unit 15 is not fixed in the spiral groove 12 by soldering or the like. This is because when the superconducting tape unit 15 is fixed in the spiral groove with solder, the superconducting tape unit 15 is directly affected by external forces such as expansion and contraction transmitted to the central tube body 11, and thus the superconducting characteristics are improved. Is deteriorated. That is, when an external force acts on the central pipe body 11, even if the central pipe body 11 expands or contracts, the superconducting tape unit 15 can independently behave in the length direction of the central pipe body 11, so that extension or strain is added. As a result, the deterioration of superconducting properties is reduced. In addition, the superconducting tape unit 15
When is in a state of being loosely inserted in the spiral groove 12 with some play, the superconducting tape unit 15 is directly cooled by the refrigerant due to the permeation of the refrigerant from the outside refrigerant return path 28 described later.

Next, as shown in FIG.
As shown in FIG. 1, the inner shield layer 20, the insulating layer 21, and the outer shield layer 22 are sequentially covered, and further outside the outer shield layer 22, the inner protective pipe 24, the heat insulating layer 25, and the outside are provided via the separator 23. A coating layer 29 including a protection pipe 26 and an anticorrosion layer 27 is sequentially arranged. The inner protective pipe 24 and the outer protective pipe 26 preferably have a corrugated shape in order to ensure flexibility. The inner shielding layer 20 is composed of a copper tape 20a wound around the outer surface of the central tube body 11 and a semiconductive layer 22b formed by winding a carbon tape around the copper tape 20a. The shielding layer 22 is composed of a semiconductive layer 22a formed by winding a carbon tape or the like on the outside of the insulating layer 21, and a copper tape 22b wound on the outside of the semiconductive layer 22a. Is configured.

The insulating layer 21 is made of kraft paper or synthetic paper (polypropylene laminated paper: PPLP) or the like, and is provided to ensure the dielectric strength. Since the electrically insulating layer 21 is formed by winding an insulating tape, the refrigerant return path 28, which will be described later, on the outer side thereof.
The liquid nitrogen of the refrigerant flowing through permeates this portion through the semiconductive layer 22a and contributes to the improvement of the insulation characteristics.

Outside the inner shielding layer 20, a refrigerant return path 28 is defined by the inner shielding layer 20, the separator 23 and the outer shielding layer 22. This refrigerant return path 28
Is a flow path through which a refrigerant such as liquid nitrogen flows. The refrigerant return path 28 is connected to the refrigerant outward path 13 inside the central tube body 11 at one end of the superconducting power cable 10, and the refrigerant outward path 13 is provided at the other end. The refrigerant return path 28 is connected to a refrigerant supply source such as liquid nitrogen (not shown), the refrigerant is supplied to the refrigerant outward path 13 from the refrigerant supply source, and the refrigerant is returned through the refrigerant return path 28. The refrigerant can be circulated over the entire length.

The separator 23 is wound around the outside of the outer shield layer 22, and is provided to form a refrigerant outward path 28 between the outer shield layer 22 and the inner protective pipe 24 outside thereof. ing. In addition, this separator 23
Is made of stainless steel wire, or CBN,
Al ₂ O ₃ , ceramics such as partially stabilized zirconia,
Alternatively, polytetrafluoroethylene (Teflon),
A linear body or a strip made of synthetic resin such as polyethylene or nylon may be used. The inner protection tube 24 and the outer protection tube 26 are made of stainless steel, aluminum, or the like, and in this example, they are corrugated to ensure flexibility, and the anticorrosion layer 2
7 is composed of a resin coating layer for anticorrosion. The inner protection pipe 24 is made of a metallic material such as stainless steel having a thickness of about 1.5 to 2 mm, and the heat insulating layer 25 is made by winding super insulation etc. and has a thickness of about 10 to 20 mm. Is.

Next, the oxide superconducting cable 1 having the above structure
On one end side of 0, the coating around the central tubular body 11 is omitted, the central tubular body 11 is projected longer than the coating layer 29 around the central tubular body 11, and the lead wire 30 is formed as shown in FIG. It is connected. In this portion, the tubular member 31 is inserted into one end of the central tubular body 11, and the inner peripheral portion of the tubular member 31 and the outer peripheral surface portion of the central tubular body 11 are superconducting tape unit 1.
5 is soldered to the outer surface portion. Therefore, the superconducting tape unit 15 is fixed to the central tube body 11 and the tubular member 31 at this one end side so as not to move in the spiral groove 12. A flexible net-like lead wire 30 is wound around and soldered to the outer peripheral surface of the tubular member 31.

On the other hand, the oxide superconducting cable 1 having the above structure
On the other end side of 0, the coating around the central tubular body 11 is omitted, the central tubular body 11 is projected longer than the coating layer 29 around the central tubular body 11, and the lead wire 38 is formed as shown in FIG. Are connected. In this portion, the retaining ring 36 is inserted at a position slightly apart from the other end of the central pipe body 11,
A ring member 37 having a diameter larger than that of the central pipe body 11 is arranged laterally of the holding ring 36 and outside the other end of the central pipe body 11, and a net-like lead wire 38 is provided on the outer peripheral portion of the ring member 37. It is connected.

Branch wires 39 of a number corresponding to the number of the superconducting tape units 15 are radially connected to the inner peripheral portion of the ring member 36 at predetermined intervals, and the tip end of each branch wire 39 is made of a conductor. The blocks 40 are attached, and each block 40 is soldered to the superconducting tape unit 15 at the other end of the central tube 11. As shown in an enlarged view in FIG. 1C, the mounting portion of the block 40 has a connecting fitting 41 attached to the tip of the mesh-like branch line 39, and the connecting fitting 41 is bolted to the block 40. It is connected. With the above configuration, on the other end side of the oxide superconducting conductor 9, the superconducting tape unit 15 can be slightly moved along with the block 40 and the branch line 39 along the spiral groove 12 of the central pipe body 11.

In order to manufacture the superconducting power cable 10, first, one or a plurality of superconducting tapes 16 are laminated, and then a necessary portion in the middle of the length direction is fixed with solder to form the superconducting tape unit 15. Then, a plurality of these superconducting tape units 15 are prepared, and these are placed in the central tube body 1.
It is individually wound along one spiral groove 12. Next, on the outside of the central tube body 11, a copper tape 22a and a semiconductive tape are sequentially wound to form an inner shielding layer 20, and an insulating tape is wound on the inner shielding layer 20 to form an insulating layer 21. Then, a semiconductive tape and a copper tape 22b are wound on it to form an outer shielding layer 22, a necessary number of separators 23 are wound on the outer side of the outer shielding layer 22, and an inner protective pipe 24 is placed on the outer side of the outer shielding layer 22 to provide super insulation. Wrap and heat insulation layer 2
5, and finally, the outer protective pipe 26 is covered to form the anticorrosion layer 27, and the oxide superconducting power cable 1 shown in FIG. 4 is formed.
You can get 0. However, when winding each of the above layers, the oxide superconducting conductor 9 is wound and covered while leaving both end portions thereof, and the unwound and uncovered portions are used for connecting current supply terminals.

After forming each coating layer of the superconducting cable 10, a tubular member 31 with a lead wire 30 is fitted into one end of the oxide superconducting conductor 9 and fixed by soldering. Next, the ring member 37 in which the lead wire 38, the branch wire 39, ... And the block 40 ... Are attached to the other end of the oxide superconducting conductor 9.
Then, the blocks 40 provided inside the ring member 37 are soldered one by one to the superconducting tape unit 15 in the central tube body 11 to complete the structure of the terminal portion.

Next, the case of using the oxide superconducting power cable 10 having the above structure will be described. In the superconducting power cable 10, the refrigerant such as liquid nitrogen is circulated through the refrigerant outward path 13 and the refrigerant return path 28 to cool the superconducting tape units 15 ...
The superconducting core 17 of No. 5 is transitioned to the superconducting state and used for energization. In this case, the superconducting core 17 is connected to the refrigerant outward path 1
Since it can be cooled by the refrigerant in 3, the stability of the superconducting core 17 can be ensured when energized in the superconducting state.

Further, since the outer shielding layer 22, the insulating layer 21, and the inner shielding layer 20 are all formed by winding a tape, the liquid nitrogen of the refrigerant flowing through the refrigerant return path 28 on the outside thereof is the same as that of the wound tape. The superconducting tape unit 15 is infiltrated from the gap to the inside thereof, and the superconducting tape unit 15 is directly cooled. Here, since the insulating layer 21 soaked with liquid nitrogen has an improved withstand voltage, the withstand voltage of the superconducting power cable 10 can be improved. Further, when the superconducting power cable 10 is energized, the superconducting tape unit 15 may be disconnected for some reason.
When the electric power source transits to the normal conducting state, it is necessary to temporarily release the large electric power supplied from the electric power supply source. In such a case, in the superconducting electromotive force cable 10 having the above structure, the central tube body 11 serves as a ground conductor for a ground fault that allows the current to escape.

Further, since the connection structure as described above is employed, the superconducting tape unit 15 has a spiral groove in the spiral groove 12 even if a force such as bending or twisting of the laying path acts on the superconducting conductive cable 10. It is possible to move a little along 12 and also to move a little along with the block 40 on the other end side of the superconducting cable 10, so that this movement can alleviate the force acting on the superconducting tape unit 10. Further, when the superconducting cable 10 is cooled with liquid nitrogen, the superconducting tape unit 1 is caused by thermal contraction during cooling.
Although stress may act on No. 5, it is possible to relax this stress and suppress the deterioration phenomenon of the superconducting characteristics as in the case described above. Therefore, the stress applied to the superconducting tape unit 15 can be suppressed at the portion where the lead wire 38 is connected, and the deterioration phenomenon of the superconducting characteristics can be suppressed. Further, the retaining ring 36 is provided in the superconducting tape unit 1 from the spiral groove 12.
Prevent lifting of 5.

FIGS. 5 and 6 show a current supply terminal structure according to a second embodiment of the present invention. In this example, a ring-shaped tubular member 42 is externally inserted at one end of the superconducting conductor 9 to form a central tube body. 11 and the superconducting tape unit 15 ..., The lead wire 44 is soldered to the outer peripheral portion of the tubular member 42, and the branch wire 46 branched from the net-like lead wire 45 at the other end of the superconducting conductor 9 ... Are individually soldered directly to the superconducting tape units 15 ... With such a configuration, the same effect as that of the example described above can be obtained.

FIG. 7 shows an example of the central tube body used in the third embodiment of the present invention. The central tube body 50 of this example is shown.
Is a plurality of through holes 51 ..., 52 in the radial direction of the central tubular body 50.
... are formed. The through holes 51 are opened to the inner peripheral surface of the central tubular body 50 and the inner bottom surface of the spiral groove 53, and the other through holes 52 are to the inner peripheral surface of the central tubular body 50 and the central tubular body 50. To the outer peripheral surface of the. With the above structure, the refrigerant flowing in the refrigerant outward path 54 inside the central tube body 50 can be guided to the superconducting tape unit 15 side through the through holes 51, ... 15 can be cooled. At this time, the refrigerant passing through the through holes 51 ...
Of the superconducting tape unit 15 to reach the superconducting tape unit 15 and cool the superconducting tape unit 15 from the peripheral side thereof.

FIG. 8 shows an example of an oxide superconducting power cable for alternating current. In this superconducting power cable 60, a superconducting tape is wound instead of the copper tape 22b of the outer shielding layer 22 in the superconducting power cable 10 described above, and the superconducting shield layer 61 is provided. Further, a semiconductive layer 21a formed by winding a semiconductive tape or the like between the insulating layer 21 and the inner shielding layer 20.
And a semiconductive layer 2 formed by winding a semiconductive tape or the like between the insulating layer 21 and the superconducting shield layer 61.
1b is provided. These semiconductive layers 21a and 21b
By providing, it becomes possible to electromagnetically shield the alternating magnetic field and the like generated at the time of energizing the alternating current.

The superconducting shield layer 61 has a thickness of 0.1 to 1 μm on a metal tape substrate such as Hastelloy tape.
From a material obtained by winding a superconducting tape on which a thin film-like superconducting layer such as a Y-Ba-Cu-O-based material is wound, or by winding a superconducting tape 16 constituting the above oxide superconducting conductor 10. It is configured. Here, in order to form a superconducting layer on the metal tape substrate, a laser deposition method,
A film forming method such as a CVD method (chemical vapor deposition method) or an MBE method (molecular beam epitaxy method) may be performed. In addition, a thickness of 5 to 5 is formed on the metal tape substrate by a doctor blade method.
A 0 μm thick film may be applied and heat-treated in an oxygen stream to form a Y-Ba—Cu—O-based thick film superconducting layer to form a superconducting tape, which may be wound.

In this winding, it is preferable to wind the superconducting tape with the metal tape substrate facing outward and the superconducting layer facing inward. As a result, when the superconducting power cable 60 is used for alternating current, it is possible to suppress the eddy current loss that occurs during alternating current use in the metal tape base material of the normal conducting portion, and to install the superconducting power cable 60. Even when it is performed, deterioration of superconducting properties of the superconducting layer can be reduced.

As a preferred example of the superconducting shield layer 61, YS is formed on the inner surface of a metal tape substrate made of a Ni-based alloy such as Hastelloy or a stainless tape.
Examples include those in which an intermediate layer made of Z (yttrium-stabilized zirconia), MgO, SrTiO ₃ , or the like and a superconducting thin film are formed. By adopting this structure, it is possible to prevent deterioration of superconducting properties as described above,
A desired magnetic shielding effect can be obtained.

The superconducting shield layer 61 has a function of repelling the magnetic field generated by the superconducting core 17 by the Meissner effect when the superconducting core 17 is energized. In particular, when an alternating magnetic field acts when an alternating current is applied, an AC loss may occur, which can be prevented by the superconducting shield layer 61.

By the way, in the above-mentioned embodiment, the terminal structure of FIG. 1B is adopted only at the other end of the oxide superconducting conductor 11, but at both ends of the oxide superconducting conductor 11, the terminal structure shown in FIG.
Of course, the terminal structure of (b) may be adopted. In the above example, the blocks 40 are attached to the superconducting tape units 15 one by one.
One block 40 may be attached to the plurality of superconducting tape units 15 within a range that does not hinder the independence within the spiral groove 12 of 5. Further, the branch lines 39 ... Connected to the superconducting tape unit 15 may be bundled together with a margin. The point is that it is necessary to prevent distortion or unnecessary external force from being applied to the superconducting tape unit 15 from the side of the current supply terminal, and such a configuration is not limited to the above configuration.

"Production Example" Bi: Pb: Sr: Ca: Cu
= Bi ₂ O ₃ , PbO, CuO, SrCO ₃ , CaC so that the composition ratio is 1.8: 0.4: 2.0: 2.2: 3.0.
Each powder of O ₃ was blended, and calcined at 800 to 840 ° C. for 74 hours was carried out four times in the atmosphere to obtain a calcined powder. The calcined powder was molded by a hydrostatic press, inserted into a silver pipe having an outer diameter of 10 mm and a wall thickness of 2.5 mm, and cold-worked until the diameter became 2.4 mm. After that, rolling and 830-84
The heat treatment at 0 ° C. for 50 hours was repeated three times to finally obtain a silver sheath Bi-based tape having a thickness of 0.1 mm and a width of 4.0 mm. Forty-five silver sheath Bi tapes were stacked and fixed by soldering to produce a superconducting tape unit having a width of 4.2 mm and a height of 4.8 mm. When this superconducting tape unit was cooled with liquid nitrogen and energized under the condition of an external magnetic field of 0 T, 22
5A could be flowed.

As the tubular body, the outer diameter is 40 mm and the inner diameter is 2
Prepare a copper pipe with a length of 0 mm and a length of 10 m.
A central tubular body was produced by forming 10 rectangular spiral grooves (helical pitch 1 m) each having a width of 6 mm and a depth of 6 mm at every 6 degrees. The superconducting tape unit was inserted into each of these spiral grooves to obtain a superconducting conductor having a length of 10 m. After this, one end of the superconducting conductor has an inner diameter of 40.5 mm, an outer diameter of 80 mm, and a length of 100.
A copper tubular member of mm was fitted therein, and the inner periphery of the tubular member and the outer surfaces of the superconducting tape unit and the central tubular body were fixed by soldering.
It should be noted that the outer peripheral portion of the ring member is provided with 300 for supplying current.
The lead wire (copper braid) for 0A is attached in advance.

On the other hand, on the other end side of the superconducting conductor, the outer diameter 20
A ring member for current supply having a diameter of 0 mm, an inner diameter of 160 mm, and a length of 50 mm is externally inserted. Ten branch lines for 300A made of a braided wire are radially arranged on the inner peripheral portion of each branch line. The base end is fixed to the inner circumference of the ring member at a predetermined interval, and the tip ends of these branch lines are all soldered to the superconducting tape unit inside the spiral groove of the central tube through a block made of copper. It is attached. The block is a copper block having a width of 3 mm, a length of 30 mm, and a height of 20 mm, and the branch line is bolted. Also, in the part 50 mm from the other end of the superconducting conductor,
2 made of stainless steel with an inner diameter of 40.5 mm and an outer diameter of 50 mm
A ring having a split structure is fitted to prevent the superconducting tape unit from rising from the spiral groove of the central tube body.

One end and the other end of the superconducting conductor having the above-mentioned current supply terminal structure are both ends of the superconducting conductor having a length of 10 m. Except for this portion, various coatings described below are applied. Construct a superconducting power cable. A copper tape having a thickness of 0.1 mm is wound on the central conductor, and a semiconductive tape containing carbon is further wound to form an inner shielding layer, and kraft paper is made to have a thickness of 6 mm on the inner shielding layer. It wound and formed the insulating layer. The thickness of the insulating layer at this time is 7
It has a structure that can withstand 10,000 V of electrical insulation. Then, a semiconductive tape and a copper tape having a thickness of 0.1 mm were wound around the insulating layer.

Next, three wires of polytetrafluoroethylene (Teflon) having a diameter of 5 mm were wound around the copper tape, and further, a thickness of 5 mm, an outermost diameter of 84 mm, and an innermost diameter of 64.
It was inserted into a corrugated internal protection pipe made of mm steel. The inside of this internal protection pipe serves as the refrigerant return path. Furthermore, super insulation is wound on this internal protection pipe to a thickness of 10 mm, and an external protection pipe made of stainless steel with a corrugate is arranged on the outside, and vinyl corrosion protection is applied to the outside to give a finished outer diameter of 135 mm. The superconducting power cable of

With respect to this superconducting power cable, liquid nitrogen was circulated using the refrigerant outward path and the refrigerant return path inside the central tube, the whole was cooled to 77K, and an energization test was conducted in an external magnetic field of 0T. As a result, 2200A, which is a value close to 10 times that of 225A obtained with the previous superconducting tape unit, could be passed through the superconducting power cable. Therefore, when 10 cables of the superconducting tape unit were put together into a cable, the deterioration phenomenon of the superconducting characteristics was hardly seen. Moreover, when the dielectric strength voltage of the superconducting power cable was measured, it was found that 80 kV was generated before flowing the liquid nitrogen refrigerant, but 100 kV was generated after flowing the liquid nitrogen.
Improved. This is because liquid nitrogen used as a refrigerant is
This is probably due to the result of seeping into the insulating layer.

Next, for comparison, a superconducting tape unit is soldered and fixed to the spiral groove of the central tube having the same structure as the above to form a superconducting power cable equivalent to the above, and the terminal portion of the superconducting conductor is formed. The structure of both ends is shown in Figure 1.
A superconducting electromotive force cable having a structure using the tubular member shown in (a) was produced and an energization experiment was conducted. As a result, about 1800A
The normal conduction transition occurred. From this result, it is considered that strain is applied to the superconducting tape unit due to thermal contraction at the stage of cooling from room temperature to liquid nitrogen temperature, causing deterioration of characteristics. Further, for comparison, an ordinary tube body having no spiral groove is used in place of the central tube body, and ten superconducting tape units are spirally wound around the body and fixed by soldering, and the above is used as a basis. A superconducting power cable having a coating layer equivalent to that was manufactured, but this superconducting power cable is capable of energizing 1000 A,
A large deterioration phenomenon of superconducting properties was observed. It is considered that this is because the superconducting tape unit was distorted or added due to the handling at the time of winding and soldering the superconducting tape unit around the outer periphery of the tube body. Also,
It is thought that the superconducting tape unit was added or distorted when the copper tape was wound around the superconducting tape unit.

[0043]

As described above, according to the present invention, since the superconducting tape unit is housed in the spiral groove on the outer periphery of the central tube, the superconducting tape unit can be formed by flowing a refrigerant such as liquid nitrogen inside the tube. It can be cooled and the superconducting core in the superconducting tape unit can be put into a superconducting state and used for conducting electricity. Furthermore, since a plurality of superconducting tape units are wound around one central tube body, the power capacity can be increased.

Further, since the superconducting tape unit is housed in the spiral groove of the central tube body in a non-fixed state, external force due to heat shrinkage, bending, etc. acting upon cooling from room temperature to liquid nitrogen temperature is applied to the superconducting tape unit. When it tries to act on, the superconducting tape unit maintains independence in the spiral groove and can be displaced in the spiral groove, so there is little risk of concentrating the addition of strain or the like on the superconducting tape unit,
The structure is such that deterioration of superconducting characteristics does not easily occur. Further, in the terminal structure on the other end side of the superconducting conductor, flexible lead wires are individually connected to the superconducting tape unit so as to maintain the independence of the superconducting tape unit, so that the room temperature to the liquid nitrogen temperature is changed. When an external force caused by heat shrinkage, bending, or the like that acts at the time of cooling tries to act on the superconducting tape unit, there is little possibility that strain or the like will be concentrated on the superconducting tape unit, and the superconducting characteristics do not deteriorate.

Further, in the oxide superconducting power cable of the present invention, since the refrigerant passage inside the pipe body and the refrigerant passage outside the pipe body are provided, the refrigerant passage inside the pipe body is filled with the refrigerant. If it is used as the outward path and the refrigerant flow path outside the tubular body is used as the return path of the refrigerant, the refrigerant can be circulated, so that the superconducting tape unit can be efficiently cooled, which contributes to stabilization of the superconducting characteristics.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing a terminal structure on one end side of a superconducting conductor according to the present invention, and FIG. 1 (b) shows a terminal structure on the other end side of a superconducting conductor according to the present invention. Perspective view, FIG.
FIG. 1C is a partially enlarged perspective view of FIG.

FIG. 2 is a sectional view showing a central tube body applied to the superconducting cable shown in FIG.

FIG. 3 is a perspective view of the central tube body shown in FIG. 1.

FIG. 4 is a cross-sectional view showing a first example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 5 is a second view of a terminal structure on one end side of a superconducting conductor.
It is a perspective view showing an example of.

FIG. 6 shows a second terminal structure on the other end side of the superconducting conductor.
It is a perspective view showing an example of.

FIG. 7 is a cross-sectional view showing a second example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 8 is a sectional view showing a third example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 9 is a perspective view showing an example of a superconducting tape unit.

FIG. 10 is a sectional view showing an example of a conventional superconducting power cable.

[Explanation of symbols] 9 superconducting conductor, 10 superconducting power cable,
11 central conductor, 12 spiral groove, 13 refrigerant outward path, 15 superconducting tape unit, 16
Superconducting tape, 17 superconducting core, 18 sheath, 30 lead wire, 31 tubular member,
36 retaining ring, 37 ring member, 38
Lead wire, 39 branch wire, 40 block, 42 tubular member, 44 lead wire,
45 lead wires, 46 branch wires, 50 central tube body,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumoto Kazuomi 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. No. 1 at Chubu Electric Power Co., Inc. Electric Power Research Laboratory (72) Inventor Naoki Hirano Kitakanyama, Otaka-cho, Midori-ku, Aichi Prefecture Nagoya No. 20 No. 1 Chubu Electric Power Co., Inc.

Claims (3)

[Claims] 1. A central tubular body is formed by forming a plurality of spiral grooves on an outer peripheral surface of a tubular body made of a metal material and forming a forward path of a refrigerant therein, and forming an oxide in each helical groove of the central tubular body. The superconducting tape unit is loosely inserted in a non-fixed state to form a superconducting conductor, and at least one end of the superconducting conductor is connected with a flexible lead wire for supplying current to the superconducting tape unit in the spiral groove. The structure of the current supply terminal for an oxide superconducting conductor, wherein the superconducting tape unit at the connecting portion is movable along with the lead wire along the spiral groove of the central tube body. 2. A central tubular body is formed by forming a plurality of spiral grooves on an outer peripheral surface of a tubular body made of a metal material and forming a forward path of a refrigerant therein, and forming an oxide in each helical groove of the central tubular body. A superconducting tape unit is loosely inserted in a non-fixed state to form a superconducting conductor, a conductive tubular member is externally inserted at one end of the superconducting conductor in the longitudinal direction, and the tubular member is placed in the spiral groove. Is fixed to the cylindrical member with a conductive adhesive, and a lead wire for supplying current is connected to the tubular member, while a plurality of flexible lead wires for supplying current are provided at the other end portion in the length direction of the superconducting conductor. And each branch line is individually connected to the superconducting tape unit in the spiral groove, and the superconducting tape unit at the connecting portion is movable along with the branch line along the spiral groove of the central pipe body. Current supply end for oxide superconducting conductor Structure of. 3. The superconducting tape unit is constituted by laminating a plurality of superconducting tapes each having an oxide superconducting core inside a tape-shaped sheath made of a conductive metal material and fixing them to each other. Claim 1 or 2 characterized
A structure of a current supply terminal for an oxide superconducting conductor according to claim 1.