JPS6025843B2 - superconducting cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting cable that has excellent mechanical strength and cooling efficiency, is lightweight, and has excellent flexibility due to the arrangement of a lattice structure.

In general, superconducting magnets used in superconducting synchrotrons, MHD generators, energy storage devices, etc.
It uses a superconducting coil made of multiple layers of superconducting cable.

Conventionally, the following superconducting cables have been known.

FIG. 1 shows a superconducting cape 4 in which a rectangular composite superconducting material 1 and flat plates 2 made of a stabilizing material having substantially the same shape are stacked alternately and joined together with solder 3 to form a single body.

This superconducting cape 4 uses a flat plate 2 made of copper as a stabilizing material to prevent burnout that occurs when transitioning from a superconducting state to a normal conducting state, so it has a heavy structure and creates a large superconducting coil with a large current capacity. Troweling is difficult.

Further, since the structure is made by laminating the rectangular composite superconducting material 1 and the stabilizing material along the longitudinal direction, the anisotropy of the compressive strength is large and the maneuverability is poor. Furthermore, this structure has the disadvantage that the cooling efficiency is low because the contact surface of the cryogenic refrigerant is limited to the surface of the superconducting cape 4. As an improved version of the superconducting cape 4, as shown in FIG. There is a superconducting cape 4 in which a plurality of twisted composite superconducting materials 1 are attached and cooling grooves 6 are formed between the flat plate 2 and the composite superconducting materials 1. Since this superconducting cape 4 is provided with cooling holes 5 and cooling grooves 6,
The contact area with the cryogenic cold soot is large, and the cooling efficiency is better than the rectangular superconducting cape 4 described above, but the strength is reduced because the cooling holes 5 are bored in the flat plate 2 made of the stabilizing material. At the same time, if the dielectric capacity is increased, the burnout prevention function by the stabilizing material cannot be sufficiently achieved.

In addition, since the cooling groove 6 is formed between the flat plate 2 and the composite superconducting material 1 twisted around the outer circumference of the flat plate 2, the shape of the side end of the superconducting cape 4 is disordered, causing stress concentration. However, there is a drawback that the superconducting properties are significantly deteriorated. Another superconducting cape 4, as shown in FIG. 3, is a superconducting cape 4 called a control cooling cable in which composite superconducting material 1 is concentrated and inserted into a tube 7 made of stainless steel. In this superconducting cape 4, the tube 7 has poor flexibility, and in order to increase the strength against compression in all radial directions, the tube 7
The disadvantage is that the wall thickness must be increased.

In view of this, as a result of various studies, the present invention has developed a superconducting cape that has excellent mechanical strength and cooling efficiency, is lightweight, and flexible, by providing a lattice structure within the superconducting cape, and has developed a superconducting cape that is lightweight and flexible. It is something.

That is, the present invention is a superconducting cape made of a composite superconducting material, a stabilizing material, and a reinforcing material, in which a lattice structure formed of at least one of the above-mentioned components is arranged on the cable. . Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 4 shows an embodiment according to the present invention, and this superconducting cape 8 is constructed by forming a lattice structure 10 using a plurality of lattice structure constituent materials 9 made of composite superconducting material 1. The lattice structure 10 has a plurality of cooling holes 11...
It is inserted along the longitudinal direction into a frame 12 having a rectangular cross-section and made of a reinforcing material with holes provided therein.

Here, as shown in FIG. 5, the lattice-structured material 9 forming the lattice-structure structure 10 is formed by forming a rectangular composite superconducting material 1 so that its strip-shaped surfaces are alternately orthogonal along its longitudinal direction. , which are molded by squeezing them at equal intervals.

Moreover, this composite superconducting material 1 has a plurality of superconducting materials 14 embedded along its longitudinal direction inside a rectangular shape 13 made of a stabilizing material. The superconducting material 14 is electrically conductive at extremely low temperatures, and its materials include alloys or compounds of niobium-titanium, nioboostin, niobium-zirconium, vanadium-gallium, and the like.

Furthermore, the stabilizing material in which the superconducting material 14 is embedded has the function of preventing burnout that occurs when transitioning from a superconducting state to a normal conducting state, and suppressing the occurrence of unstable phenomena such as flux jumps that occur at that time. The material is one with excellent thermal conductivity and thermal properties, such as copper or copper-aluminum composite.

Further, the reinforcing material forming the frame 12 housing the lattice structure 10 is provided to increase the mechanical strength of the superconducting cable 8, and has higher hardness than the stabilizing material.

Examples of the material include stainless steel, stainless steel-copper, stainless copper, and aluminum. Further, in the frame 12 made of this reinforcing material and having a rectangular cross section, a plurality of cooling holes 11 are bored with equal distances between them. ... serve as refrigerant flow holes, through which cryogenic refrigerants such as liquid helium flow in and out, thereby increasing the cooling efficiency of the superconducting cable 8.

The superconducting cable 8 having the above structure is used in a superconducting state by being immersed in a cryogenic refrigerant, but the lattice structure 10 is housed within a frame 12 made of reinforcing material and having a rectangular cross section. Due to the reinforcing effect of the reinforcing material and the strong lattice structure of the lattice structure 10, it has high compressive strength, and the lattice structure material 9 forming the lattice structure 10 has a gap formed between them. 15 is a refrigerant passage, which has a large cooling area and has high cooling efficiency.

As another embodiment of the present invention, in the superconducting cable 8 shown in FIG. A composite superconducting material 1 having a circular cross-section, a square cross-section, etc. is inserted into the gap 15 or around its outer periphery, or is wrapped around the composite superconducting material 1, which is more flexible than the superconducting cable 8 shown in FIG. An improved superconducting cable may also be used.

In addition, in the superconducting cable 8 shown in FIG. 4, the reinforcing material is used to form the lattice structure constituent material 9, and the gaps 15 formed within the lattice structure are filled with composite shapes such as circular cross-sections and square cross-sections on the outer periphery. A superconducting cable 8 having a superconducting material 1 inserted therein or wound therein and having a higher mechanical strength such as compressive strength than the superconducting cable 8 shown in FIG. 4 may be used.

Alternatively, as shown in FIG. 6, two flat plates 16b, 16b made of a stabilizing material having the same shape are attached to both sides of a band-shaped flat plate 16a made of a reinforcing material, and the integrated flat plate 16a is made of a reinforcing material. Round bar 17 made of multiple stabilizing materials on the surface...
... is passed through and fixed in a grid pattern, and this round bar 17...
. . . and the flat plate 11a made of reinforcing material as shown in FIGS. 8 and 9.
As shown in the figure, a lattice structure 10 is formed, and a round hole 17 protrudes from the outer peripheral surface of the lattice structure 10.
- In between, as shown in FIG. 7, a superconducting cable 8 formed by winding a plurality of composite superconducting materials 1 in a spiral shape may be used.

Next, specific examples according to the present invention will be described.
Example 23 Niobium titanium superconducting material 14 was added to the oxygen-free steel stabilizing material.
An angular composite superconducting material 1 with a length of 280 m and a cross-sectional outline of 3 kites x 9 skins with 00 cores embedded was prepared, and the strip-shaped surfaces of this rectangular composite superconducting material 1 were alternately orthogonal along its longitudinal direction. As shown in the figure, the twisting pitch is 6 strands, and the strands are twisted at equal intervals.
A lattice structure constituent material 9 as shown in the figure was prepared.

This lattice structure forming material 9 was placed in a solder bath at 320 pm and solder plated, and 14 pieces were bonded together in a lattice shape to form a lattice structure 10 as shown in FIG. This lattice structure 10 is made of stainless steel as a reinforcing material and has an external cross section of 18 legs x 48 fences and an internal cross section of 16 kites.
The inner wall surface on the 46 side is plated with copper to a thickness of 20 m, and the cross section is rectangular in which a plurality of cooling holes 11 of 3 holes are bored at a distance of 8 mm from each other. Shaped hollow frame 1
I inserted it into 2. . This was compressed while being heated at 28,020° C. for 30 minutes to form the lattice structure 10 and the frame 1.
2 is joined, and the outer cross section 17 side x 47 as shown in Fig. 4.
A side superconducting cable 8 was obtained. When this superconducting cable 8 was subjected to a current test, a compression test, and a bending test, the results shown in Table 1 were obtained.

Comparative Example In order to compare the characteristics with the superconducting cable 8 in the above-mentioned example, a superconducting cape 4 as a comparative sample was produced in the following manner.

2300 niobium titanium superconducting material 4 as oxygen-free steel stabilizing material
A composite superconducting cave with a diameter of 10.5 feet◇ with a buried core.
After twisting at a twisting pitch of 5 m, a flat wire of 280 h of 3 ribs x 9 legs was obtained by rolling.

This was placed in a 32000 solder bath and solder plated. Fourteen of these solder-plated rectangular composite superconducting materials 1 were prepared, and an external cross-section 1 made of stainless steel was prepared.
8 legs x 48 fences, inner flea cross section 10 ribs x 43 legs inner wall surface 20
A rectangular hollow frame body which is coated with copper to a thickness of mm m and has a plurality of three cooling holes 11 spaced apart from each other by 8 mm. I inserted it into 12. This was compressed while heating at 28,000 for 30 minutes, and the first
A superconducting cape 4 as shown in Fig. 0 was obtained. This superconducting cape 4 was subjected to a current conduction test, a compression test, and a bending test in the same manner as the superconducting cable 8 shown in the above example, and the results shown in Table 1 were obtained. Note that in the above examples, the current conduction test was conducted under a magnetic field of 4.2 K and 8 Tesla.

The reason that the current variation in the comparative example superconducting cable 4 is larger in the current carrying test shown in Table 1 '11 is because the frame body 12 made of stainless steel is thicker than that in the example superconducting cable 8. This is thought to be due to the large current loss and low cooling efficiency.

Moreover, from the results of the compression test (2), it can be seen that the superconducting cable 8 of the example in which the lattice structure 10 is provided within the cable has a much higher compressive strength than the superconducting cape 4 of the comparative example. In addition, from the leg bending test, if the bending rigidity of the superconducting cable 8 of the example is 1, the superconducting cape of the comparative example has about 6 times the bending rigidity, and compared to the superconducting cape 4 of the comparative example, the superconducting cable of the example It can be seen that No. 8 has higher flexibility. Further, when comparing the weights of the superconducting cables 4 and 8, the weight of the superconducting cable 4 of the comparative example was 1.5 times that of the superconducting cable 8 of the example. As described above, the superconducting cape according to the present invention has the lattice structure arranged in the cable, thereby increasing mechanical strength, improving flexibility, and enabling stable current conduction.

Furthermore, since the superconducting cape is lightweight, it has remarkable effects such as making it easier to make large superconducting coils for large currents and the like.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional superconducting cape in which a flat composite superconducting cape and a stabilizing material are alternately stacked;
FIG. 2 is a perspective view showing a conventional superconducting cape having cooling holes and cooling grooves, FIG. FIG. 4 is a sectional view showing a superconducting cape in which a lattice structure is formed using a composite superconducting material according to the present invention, FIG. 5 is a perspective view showing a lattice structure forming material made of the composite superconducting material, and FIG. 7 is a perspective view showing a lattice structure formed of a stabilizing material and a reinforcing material according to the present invention, FIG. 7 is a perspective view showing a superconducting cape provided with the lattice structure shown in FIG. 6, and FIG. is a sectional view showing a cross section along the wind line in FIG. 7,
FIG. 9 is a cross-sectional view taken along the line KK in FIG. 7, and FIG. 10 is a perspective view showing a superconducting cape in a comparative example. 1... Composite superconducting material, 2... Flat plate, 4
...Superconducting cape, 8...Superconducting cable,
9... Lattice structure constituent material, 10... Lattice structure, 12... Frame, 14... Superconducting material 15... Gap portion . Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. A superconducting cable consisting of a composite superconducting material, a stabilizing material, and a reinforcing material, characterized in that a child tissue structure formed of at least one of the above-mentioned components is arranged in the cable.