JPS59132513A - Method of forming separator in forcibly cooling superconductive conductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting wire used in a superconducting coil of a superconducting magnet such as a nuclear fusion reactor, and particularly to a type of superconducting wire subjected to forced circulation cooling f, II using a cold fJ1 medium.

Recently, a so-called hollow superconducting wire with a cooling medium passage formed in the center of its cross section has been used, and a cooling medium such as supercritical pressure helium is forced to circulate in the cold medium passage.

Various superconducting coils have been proposed in which superconducting wires are forcibly cooled from inside. A hollow superconducting wire used in such a superconducting coil is, for example, as shown in FIG. A model in which the strands 3A are embedded, or a model in which the ultrafine multicore superconducting strands 3B are wound or twisted around the outer surface of a stabilizing base material 2 made of copper or the like, which also has a rectangular cross section, as shown in Fig. 2. Furthermore, as shown in FIG. 3, grooves 4 are formed on the outer surface of a stabilizing base material 2 having a rectangular cross section, and molded superconducting wires 3C are fitted and fixed in each groove 4. There are things like that.

In a superconducting magnet using such a forced cooling type superconducting wire, a cold fJ] medium is forcedly circulated inside the conductor, so each part is cooled evenly, and the coil is
Although it has the advantage of having high mechanical strength and requiring only a small amount of cooling medium, on the other hand, the cooling of the superconducting wire is indirect cooling via a stabilizing base material such as copper. As a result, cooling efficiency is low, and therefore, if a heat spot occurs in a part of the superconducting wire for some reason and the superconducting properties are lost, there is a problem in that recovery is delayed.

On the other hand, as shown in FIG. 4, a large number of superconducting strands 3B are accommodated inside the square cylindrical body 6, and gaps 7 between the superconducting strands 3B are accommodated.
A so-called handle-type superconducting wire has also been proposed in which a cooling medium such as liquid helium is not allowed to flow through the superconducting wire, and in this case, the surface of the superconducting wire 3B is brought into direct contact with the cooling medium for direct cooling. However, in this type of superconducting wire, cold f! It is quite difficult to flow the I medium smoothly, and the flow of the cold body is locally stagnated, the temperature rises, and heat spots occur, and the heat spots do not recover quickly. There are some drawbacks.

Therefore, the inventors of the present invention incorporated the advantages of the hollow superconducting wire and the direct cooling type superconducting wire shown in FIG. 4 to achieve high overall cooling efficiency (and good local stability). A special application was made in 1973 for a superconducting wire with a structure that could withstand large electromagnetic forces.
It is proposed in No. 7-45795. An example of this proposed superconducting wire is shown in FIG.

In FIG. 5, inside a hollow stabilizing base material 10 with a rectangular cross section made of a highly conductive material such as copper, copper alloy, high purity aluminum, or aluminum alloy, Nb Ti alloy,
A plurality of superconducting strands 11 made of an alloy superconducting material such as NbT;-Ta alloy or a compound superconducting material such as Nb3Sn, V3Ga, Nb5G8, etc. are accommodated. The outer surface of the stabilizing base material 10 is made of copper, stainless steel, etc. through an appropriate number of separators 12 made of the same material as the stabilizing base material 10 or stainless steel.
It is surrounded by an outer cover 13 having a rectangular cross section made of H, titanium, titanium alloy f1, etc., and a cooling medium flow path 14 is secured between the outer surface of the stabilized Bl material 10 and the inner surface of the outer layer 113 by the lever regulator 12. ing. Further, the stabilizing base material 10
A communication passage 15 is formed in the shape of a round hole, a long hole, or a slit shape, which communicates the cold 2JI medium flow path 14 on the outside with the space on the inside. Therefore cold i
A cooling medium such as jfl critical pressure helium flowing through the Jl medium flow path 14 flows through the communication path 15 and flows into the gap 16 between the wires of the superconducting wires 11 inside the stabilizing base material]O. The cooling medium comes into direct contact with the A flow of the cooling medium also occurs in the inter-wire gaps 16 of the superconducting wires 11 inside the stabilizing base material 10.

In the above-proposed superconducting wire, overall cooling is achieved by a steady flow of the cooling medium flowing through the cooling medium channel 14 outside the stabilizing base material 10, so uniform cooling is achieved as in the case of conventional hollow superconducting wires. In addition, the superconducting wire 11 itself inside the stabilizing base material 10 is also directly cooled by the cold f, II medium, so cooling efficiency is high, and the cooling of the outside of the stabilizing base material 10 is improved. Since the medium and the inside θ cooling medium are exchanged by flowing in and out through the communication path 15, the inside cooling medium is It is extremely unlikely that a heat spot will occur due to a localized temperature rise, or that its recovery will be delayed, which will impair the overall cooling efficiency and at the same time reduce steady-state stability.

It also has excellent transient stability. In addition, in the superconducting wire proposed above, when disturbance occurs and the superconducting state is broken and a magnetic flux flow state occurs, the current is shunted to the stabilizing R1 material, so heat is generated even in the stabilizing base material. However, since the heat generated by the stabilizing base material is also cooled by the cooling medium on the outside, the superconducting state can be recovered more quickly than with the conventional handle-type direct cooling method shown in Figure 4. As mentioned above, the cooling medium inside and outside the stabilizing base material flows in and out through the communication path, so that the aggregate structure of superconducting wires in the stabilizing base material cools fJ in the longitudinal direction.
1. Even if the medium does not flow smoothly, for example, a braided structure or a formed stranded wire structure, there is no particular problem.Therefore, there is no restriction on the aggregate structure of superconducting wires, so there is a great degree of freedom in its design. Since the strands are placed in the central valve of the superconducting wire, there is little deterioration in the characteristics of the superconducting strands due to the effects of bending strain when wound around a coil such as a magnet. Ultra ml is protected by external electromagnetic force because it is protected by a
It has much superior properties compared to conventional superconducting wires, such as effectively preventing loss (b deterioration) of the cable wires.

In the superconducting wire shown in FIG. 5, a plurality of superconducting strands 1
1 superconducting wire assemblies 17A and 17B are stacked in two layers and accommodated in the stabilizing base material 10, and a high resistance conductive material such as cupronickel is placed between the two layers of superconducting wire assemblies 17A and 17B. A thin chip 718 made of material is inserted so that the superconducting wire assemblies 1.7A and 17B of each layer do not come into direct contact with each other. By configuring like this,
A coupling current flows between each layer, making it possible to prevent deterioration of superconducting properties when the excitation speed is relatively high, such as in pulse drive. Furthermore, in FIG. 5, a thin tape 19 made of the same high-resistance conductive material is inserted between the superconducting wire aggregates 17A, 17B of each layer and the stabilizing base material 10. This tape 19 is
It serves to prevent a coupling current from flowing between both layers through the stabilizing base material 1°. However, in order to simplify the drawing, in FIG. 5, the tape 19 is shown provided on the entire outer surface of each JS17A and 17B, but in reality, the tape 19 is provided on the entire outer surface of each JS17A and 17B, but in reality, the tape 19 is provided so as not to obstruct the inflow of the cooling medium from the communication path 15. It is usual to form a space as appropriate.

As described above, the proposed superconducting wire has better cooling efficiency and stability than conventional superconducting wires, and also has excellent mechanical strength against bending and external forces, and can be used for various purposes in addition to nuclear fusion. It is ideal for various applications such as electrical machinery, energy storage, magnetic resonance absorption, magnetic separation, etc., especially for superconducting wires for large, high-field magnets, and is especially suited for use in high-resistance electrical materials by accommodating superconducting wires in multiple layers. In the case where a conductor 718 or one conductor is inserted, the coupling current between each layer is prevented by the high-resistance conductive tape, so it is suitable for pulse applications using large currents. However, when the authors of the present invention conducted further research for practical application, it was discovered that the above-mentioned proposed superconductor had the following problems.

That is, in this scale fi conductive wire, the stabilizing base material 10
As a means for providing a separator 12 for maintaining the cold fJ'l medium flow path 14 between the casing 13 and the jacket 13, as shown in FIG. It has been considered to attach this to the outside of the stabilizing base material 10 in an open Ijj4 spiral shape. However, in the ffl conductive wire in which the separator 12 is wound around the outside of the stabilizing base material 10, the separator 12 tends to tighten when it is bent for coil winding, making it difficult to bend, especially It became difficult to perform coil winding to a small diameter, and if you tried to forcefully bend it, there was a risk that the bending would be uneven, or that the stabilizing base material would crack or buckle.

Also, a method has been proposed in which the separator 12 is not wrapped around the stabilizing base material 1o but along the outer surface of the stabilizing base material 1o.
There is a problem in that it is difficult to bring the stabilizing base material 10 and the separator 12 into close contact with each other, and a gap may exist between the stabilizing base material 10 and the separator 12. If there is no gap between the stabilizing base material 1° and the separator 12, the magnets 1-
The above-mentioned gap between the stabilizing base material 1o and the separator 12 allows the movement of the stabilizing base material 10 and the inner layer opening due to the electromagnetic force generated when it is normally wound into a coil for use in, for example,
This causes quench to occur.

Therefore, the present inventors proposed a method of integrally forming a protrusion on the outer surface of the stabilizing base material 10, and making the protrusion function as the separator 12 to secure the cooling medium flow path. . That is, as shown in FIG. 7, one or more protrusions 20 are integrally formed along the longitudinal direction on each surface of the outer periphery of the tenth stabilizing plate 14, which has a substantially rectangular cross section as a whole. As shown in Figure 8, this protrusion 2
0 as the cooling medium flow path 1 between the outer jacket 13 and the stabilizing base material 10
The separator 12 functions as the separator 12 for securing the 4. When a superconducting wire using the stabilizing base material 10 integrally formed with the ridges 20 that functions as a separator is bent for coil winding, the ridges 20
The parts act as one with the stabilizing base material 10, and therefore can be bent much more easily than when a separate separator 12 is wrapped around the stabilizing base material 10. Since the material 10 and the protrusion 20 are integrated, no gap is created between the stabilizing base material 10 and the separator 12 even after the outer sheath 13 is covered and molded.

Further, the present inventors have proposed the following means for integrally forming the protrusion portion 20 that serves as a separator on the stabilizing base material 10 as described above.

That is, as shown in FIG. 9(A), a tape-shaped material 21 made of a highly conductive material such as oxygen-free copper is processed by roll rolling or the like as shown in FIG. 9(B), and the surface thereof is A plurality of protrusions 20 are formed, and then this is shown in FIG. 9 (,C).
As shown in the figure, another tape-shaped material 22 is bent into a mouth-shaped channel shape, and on the opening side of the mouth-shaped channel-shaped material 21 obtained in this way, protrusions glj 20 are formed in the same manner as described above. As shown in FIG. 9(D), the entire structure is made into a rectangular cross-section.

However, forming the protrusions 20 by rolling the material 21 as in the above method is not easy in itself;
Further, when the present inventors conducted a rough research for practical application, it was found that the above-mentioned means had the following problems.

That is, according to the means described in -F, the protrusion 20, and hence the cold N'l medium passage 14, is created by roll rolling, but in that case, the protrusion 20 in FIG. 9(B) is created by roll rolling.
．． In the trough between 20 and 20 degrees, the part cut by the roll flows in the longitudinal direction, causing wrinkles, and in the width direction, tensile force acts on the cut part from both sides of the chair, making it easy to crack.

Therefore, this invention was made in view of the above circumstances, and further improves the superconducting wire described in Japanese Patent Application No. 57-45795, makes coil winding easier, and provides a stabilizing matrix during coil winding. In order to prevent gaps from forming between the material and the separator, the stabilizing base material and the separator are manufactured in an integrated manner so that processing can be easily performed and no defects occur in the material during processing. The present invention aims to provide a method for forming a separator for a forced cooling superconducting wire.

That is, in the present invention, a plurality of superconducting strands are housed inside a stabilizing base material having a rectangular cross section and is hollow, and a separator is provided between the stabilizing base material and an outer sheath surrounding the stabilizing base material. A cooling medium flow path continuous in the longitudinal direction of the stabilizing base material is formed by the separator 1, and a communication path is formed in the stabilizing base material to communicate the inside and outside of the stabilizing base material, The forced cooling type superconducting wire is configured such that the cold N1 medium flowing through the cooling medium yPL path can directly cool the superconducting strands in the stabilizing base material through the communication path. In forming the separator of the forced cooling type superconducting wire in which the striations are integrally formed and the protruding striations serve as the separator for securing the cooling medium flow path, the above-mentioned stabilizing base material and the separator material are used. The board material itself is formed to have undulating peaks and troughs, and the peaks are joined to the opposing surfaces of the inner gap (this is successively narrowed in the width direction, and the inner opposing surfaces are joined to each other). The plate material is characterized in that a separator is formed by joining and using the peak portion as a protrusion from the plate material.

The separator forming method of the present invention will be explained in more detail below.

@Figure 10 sequentially explains the steps of the separator forming method of the present invention. First, as shown in FIG. 10 (a), a smooth tape-shaped material 21a made of a good conductive material such as oxygen-free copper is inserted into the crest 2 as shown in FIG. 10 (1).
3.23 and troughs 24.24 (J is molded into a wavy plate material 21b. This plate material 211) is formed into the protruding portion 20 by rolling as shown in FIG. 9 above.
．． 20 is different from the plate material 21 in which the plate material itself is undulating to form peaks 23.23 and troughs 24.24. In addition, the top of this mountain part 23.23 and the valley part 24.
The bottoms of 24 are mutually parallel planes. Furthermore, as shown in FIG. 10(C), the diameter J in the width direction of the peaks 123. 21 [1 mountain part 2
3.23 is sequentially narrowed down in the width direction. Finally, as shown in FIG. 10(d), the peak 23
．． 23 is eliminated, and the inner surfaces are firmly joined to each other. By doing this, the mountain part 2
3.23 is a protrusion that protrudes from the plate material 21d at a constant interval, and this plate material 21(d) is stabilized by the above-mentioned stabilization ff1'.
When molded as +A10, it functions as a separator that secures and covers the cooling medium flow path.

Incidentally, each of the above steps can also be carried out by using a rolling roll or a cassette roll with appropriate roll design.

As described above, according to the present invention, in forming a separator integral with the stabilizing base material on the outer surface of the stabilizing base material of a forced cooling type superconducting wire, the stabilizing fil material and the plate material that is the material of the separator are used. By molding the lever into an undulating shape with peaks and troughs, and narrowing the peaks in the F-th width direction to form protrusions that function as separators, the lever can be stabilized. When formed integrally with a material, the material can be easily processed, and destruction due to buckling or cracking can be prevented.

Furthermore, by integrating the separator and the stabilizing base material, there is no gap between the separator and the stabilizing base material even when the wire is wound around a coil, so even if electromagnetic force is applied, the wire will not move. Does not occur.

[Brief explanation of the drawing]

1 to 3 are V cross-sectional views showing an example of a conventional hollow superconducting wire, FIG. 4 is a cross-sectional view showing an example of a conventional direct cooling superconducting wire, and FIG. 5 is a cross-sectional view showing an example of a conventional directly cooled superconducting wire. A perspective view showing an example of a superconducting wire proposed in
FIG. 7 is a perspective view showing an example of the stabilizing base material used in the superconducting wire of the present invention, and FIG. 8 is a perspective view showing the stabilizing base material and separator in the superconducting wire of the present invention. Figure 9 is a perspective view showing an example of a superconducting wire using
) to (D) are cross-sectional views showing a method of forming an IF3 conductive wire separator as an example of a method of manufacturing a stabilizing base material. 10... Stabilizing base material, 11... Superconducting wire, 1
3... Outer cover, 14... Cooling medium passage, 15...
・Communication path, 20... Protrusion portion, 23... Mountain portion, 2
4...Tanibe. Applicant Fujikura Electric Cable Co., Ltd. Agent Patent Attorney Takehisa Toyota (and one other person) 73 Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] A plurality of superconducting strands are housed inside a hollow stabilizing base material with a rectangular cross section, and a separator is provided between the stabilizing base material and an outer sheath surrounding it. A cooling medium flow path continuous in the longitudinal direction of the stabilizing base material is formed, and a communication path communicating between the inside and outside of the stabilizing material is formed, and the cooling medium flowing through the cooling medium flow path is A protrusion is integrally formed on the outer surface of the stabilizing base material of a forced cooling type superconducting wire configured to directly obtain a cold IJ1 injection of the superconducting wire in the stabilizing base material through a communication path. In forming the separator of the forced cooling superconducting wire in which the striations serve as separators for securing the cooling medium flow path, the stabilizing base material and the plate material itself which is the material of the separator have peaks and valleys. The peaks are successively narrowed in the width direction so that the opposing surfaces of the inner voids are joined, and the inner opposing surfaces are joined together to form the peaks into protrusions from the plate material. A method for forming a separator in a forced cooling superconducting wire, characterized in that the separator is formed by forming strips.