JPS6026243B2 - superconducting cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting cable that has a honeycomb structure and has excellent mechanical strength and cooling efficiency.

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, superconducting cables having the following structure are known.

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

This superconducting cable 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 can create a large superconducting coil with a large current capacity. is difficult.

In addition, a flat plate 2 made of a rectangular composite superconducting material 1 and a stabilizing material
Because of the structure in which the two are bonded together along the longitudinal direction, the anisotropy of the compressive strength is large and the flexibility is poor. Furthermore, this structure has the disadvantage that the cooling efficiency is low because the contact surface with the cryogenic cold butterfly is limited to the surface of the superconducting cable 4. As an improved version of the superconducting cable 4, as shown in FIG. 2, a plurality of pipe-shaped cooling holes 5 are provided along the longitudinal direction.
A plurality of twisted composite superconducting materials 1 are attached to both sides of a flat plate 2 made of a stabilizing material with ...... There is a superconducting cable 4 formed with a cable 6.

Since this superconducting cable 4 is equipped with cooling holes 5 and cooling grooves 6, the contact area with ultra-low overflow soot is large, and the cooling efficiency is better than that of the rectangular superconducting cable 4.
Since the cooling holes 5 are formed in the flat plate 2 made of the stabilizing material, the strength is reduced, and if the current capacity is increased, the burnout prevention function by the stabilizing material cannot be sufficiently achieved.

In addition, since the flat plate 2 is installed so as to form a cooling groove 6 between the composite superconducting material 1 twisted around its outer periphery, the shape of the side end of the superconducting cable 4 is disordered, causing stress concentration. However, there is a drawback that the superconducting properties are significantly deteriorated. In addition, as another superconducting cable 4, there is a superconducting cable 4 called a forced cooling cable, which is made of multiple composite superconducting materials 1 and inserted into a tube 7 made of stainless steel, as shown in FIG. .

This superconducting cable 4 has the drawback that the tube 7 has poor flexibility, and the wall thickness of the tube 7 must be increased in order to increase its strength against compression in the radial direction. In view of the above, the present invention has been made based on various researches and has resulted in the creation of a superconducting cable that has superior mechanical strength and cooling properties, as well as maneuverability, by providing a honeycomb structure within the superconducting cable. .

That is, the present invention provides a superconducting cable consisting of a composite superconducting material, a stabilizing material, and a reinforcing material, in which any one of the above constituent parts is
A honeycomb cell having a hollow portion made of seeds and a frame formed of one of the remaining two types of the constituent members are filled with one of the last remaining constituent members as a filler. This is a superconducting cable equipped with a honeycomb structure made up of honeycomb cells.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

FIG. 4 shows an embodiment of the present invention, and this superconducting cable 5 is a honeycomb structure made of a cell frame of a composite superconducting material 1 in which a filler 7 made of a stabilizing material is placed in a hollow part 6. A honeycomb structure 9, which is formed into a band shape by coarsely fitting cells 8a and honeycomb cells 8b having hollow portions 6 made of reinforcing material in multiple stages alternately, is provided with a plurality of cooling holes 10 from both sides along its longitudinal direction. It is fixed by a pair of upper and lower flat plates 11, 11 and a pair of left and right side plates 111, 111 made of a reinforcing material with holes.

One honeycomb cell 8 constituting the honeycomb structure 9
As shown in FIG. 5, a shows a composite superconducting material 1 in which a plurality of superconducting materials 12 are embedded inside a stabilizing material.
to form a cell frame with a hexagonal cross section having a hollow part 6,
This hollow portion 6 is further filled with a stabilizing material as a filler 7.

This superconducting material 12 has a superconducting state at extremely low temperatures, and may be any material such as an alloy or compound of nioboo tin, niobium zirconium, nioboo titanium, vanadium-gallium, or the like. In addition, both the stable material forming the composite superconducting material 1 and the stabilizing material serving as the filler 7 prevent burnout that occurs during the transition from the superconducting state to the normal conducting state, and also prevent the flux jump that occurs at that time. This is to suppress the occurrence of unstable phenomena such as

The material is lower in hardness than the reinforcing material and has excellent electrical conductivity and thermal conductivity, such as copper, copper-aluminum composite, and aluminum. Further, the other honeycomb cell 8b constituting the honeycomb structure 9 has a hexagonal cross-section with a hollow part 6 formed without any stable material inside, and the material is harder than the stabilizing material. Made of highly reinforcing materials, such as stainless steel,
These include copper alloys and aluminum alloys. Further, a pair of flat plates 11, 11 and 1 sandwiching the honeycomb structure 9 are provided.
The pair of side plates 111, 111 clamp and fix the honeycomb structure 9 to increase the mechanical strength of the superconducting cable 5, and also have a plurality of cooling holes 10 bored in the planes of the flat plates 11, 11 and 111, 111. This is provided to increase the cooling efficiency of the superconducting cable 5 by supplying cold soot from .

The materials of the flat plates 11, 11 and the side surfaces 111, 111 increase the mechanical strength of the superconducting cable 5, and are the same as those forming the honeycomb cells 8b, such as stainless steel, steel alloy, etc. , aluminum alloy, etc. Superconducting cable 5 with such a structure
is used in a superconducting state by immersing it in a cryogenic refrigerant, but since it has a honeycomb structure 9 in the cable, it has high compressive strength and high bending rigidity, and the honeycomb cell 8a
The stabilizing material filled in the cell frame that makes up the
This suppresses the occurrence of unstable phenomena such as flux jumps that occur when transitioning from a superconducting state to a normal conducting state. Furthermore, the hollow part 6 of the honeycomb cell 8b becomes a cold soot passage,
It has a large cooling area and can achieve extremely high cooling efficiency. In addition, other superconducting cables 5 according to the present invention
As shown in FIG. 6, the hexagonal cross section of the honeycomb structure 9, which is filled with a stabilizing material 7 and has cooling holes 10, is made of a pair of superconducting materials 12 embedded in the stabilizing material. The superconducting cable 5 may be formed into a band shape by sandwiching the composite superconducting materials 1 and 1 from above and below.

Further, as shown in FIG. 7, a honeycomb structure 9 is inserted along the longitudinal direction inside a hollow cylindrical frame 13 made of reinforcing material, and solder powder and copper Superconducting cable 5 filled with powder in equal proportions and fused to the body
That's fine.

Furthermore, in the honeycomb structure 9 according to the present invention, instead of the honeycomb cells 8a filled with a stabilizing material as the filler 7, a cell frame with a hexagonal cross section having a hollow portion 6 is formed using a reinforcing material, The honeycomb structure 9 may be formed using honeycomb cells 8 in which the composite superconducting material 1 is filled as the filler 7 in the hollow portion 6.

Alternatively, a cell frame with a hexagonal cross section having a hollow portion 6 is formed using the composite superconducting material 1, and a honeycomb structure 9 is formed using a honeycomb cell 8 in which the hollow portion 6 is filled with a reinforcing material as a filler 7. It may also be a formed one. Further, as another superconducting cable 5 according to the present invention, as shown in FIG.
A strip-shaped composite superconducting material 1 in which . The honeycomb structure 9 is constructed by twisting a plurality of these constituent materials 14 stacked one on top of the other.

As shown in FIG. 10, the honeycomb structure 9 has a frame 13 with a rectangular cross section made of a reinforcing material and having a plurality of cooling holes 10 formed therein.
A superconducting cable 5 inserted inside may also be used. Next, specific examples according to the present invention will be described.

Example 1 First, a composite superconducting material 1 in which 1280 niobium titanium filaments were embedded had an inner diameter of 4.5 mm. , outer diameter 4.
85 kites? After filling the hollow tube 6 with a stabilizing material made of aluminum as the filler 7, a cell frame body having a hexagonal cross section on the side with an external distance across flats of 4.5 is formed to form a honeycomb cell 8a. did.

Next, a hollow cross-sectional hexagonal honeycomb cell 8b made of Cypronic steel with an external side-to-side distance of 4.5 and 0 skin is prepared, and this honeycomb cell 8b and the aluminum-filled honeycomb cell 8a are combined in multiple stages and solder plated. After this, the honeycomb structure 9 was obtained by twisting this at the outermost pitch of 120 columns. This honeycomb structure 9 is placed on the inner wall surface to a thickness of 1
It is inserted into the frame 13 which is made of a stainless steel pipe with a wall thickness of 1.5 mm, an outer diameter of 26 mm, and a length of 200 mm, which is coated with 0.01 copper, and is formed between the frame body 13. A mixture of solder powder and steel powder in a 1:1 ratio was filled into the gap 15. Thereafter, the frame body 13 and the honeycomb structure 9 were soldered together by heating at 250° C. for 10 minutes to obtain a superconducting cable 5 as shown in FIG. This superconducting cable 5 was subjected to a current conduction test, and the results shown in Table 1 were obtained.

In addition, in the current conduction test, this superconducting cable 5 was
A frame body 13 made of a stainless steel tube is formed into a skin coil shape, and is cooled by flowing liquid helium in and out from the end thereof.
The outside was also cooled with liquid helium to 4.2K, and then further heated to 8K.
This was done by applying Tesler's magnetic field. Comparative Example 1 In order to compare with the superconducting cable 5 of Example 1, a superconducting cable 4 as a comparative sample as shown in FIG. 8 was made in the following manner.

512 pieces of niobium titanium superconducting material 12 are embedded in a frame 13 made of a stainless steel pipe with a wall thickness of 1.5 mm and an outer diameter of 26 skin ◇. Oxygen-free steel composite superconducting material 1 and outer diameter 2 with an outer diameter of 22 skin J are embedded. .2 ribs ◇ high-grade aluminum wire 7a and the outermost pitch 1
Insert 30 strands twisted together on two sides, and make a length of 5.
A 0W superconducting cable 4 was obtained.

This superconducting cable 4 was also subjected to the same energization test as was conducted on the superconducting cable 5 shown in Example 1, and the test results shown in Table 1 were obtained.

Although the superconducting cable 5 of Example 1 reached the design value of 5.00M and 20M in the current conduction test shown in Table 1,
Superconducting cable 4 of Comparative Example 1 did not meet this value,
Moreover, the reason why flux jumps were observed was due to the poor cooling efficiency of the frame 13 made of stainless steel pipes and the fact that the frame 13
This is thought to be due to the movement of the composite superconducting material 1 within the interior.

The above experiment shows that the superconducting cable 5 according to the present invention can perform stable energization from the first time. Example 2 A band-shaped composite superconducting material 1 in which 1280 niobium titanium superconducting materials 12 are embedded is bent into a trapezoid shape at equal intervals along the longitudinal direction at a bending angle of 12 mm to form one half of a honeycomb structure 9. I made 14 constituent materials.

Twelve strips of this component material 14 coated with copper are prepared and assembled so that the cross section has a hexagonal shape.
The honeycomb structure 9 is made by twisting at an angle of 5o, and the honeycomb structure 9 has cooling holes 10 in three ribs that serve as cold soot passages.
were inserted into a frame 3 with a rectangular cross section whose inner walls were plated with copper, and then 25
The superconducting cable 5 as shown in FIG. 10 was obtained by heating at 0° C. for 1 inch and bonding it to the inner wall surface of the frame 13. This superconducting cable 5 was subjected to a bending test and a compression test, and the results shown in Table 2 were obtained.

Comparative Example 2 In order to compare with this superconducting cable 5, a superconducting cable 4 as a comparative sample as shown in FIG. 11 was made in the following manner.

A composite superconducting material 1 with a cross section of 1 side x 2.5 sides in which 340 pieces of niobium titanium superconducting material 12 were embedded was formed into a cross section of 2 winds x 6 yards by rolling 4 threads at a pitch of 12 yards.

This is inserted into a frame 13 made of oxygen-free steel with external dimensions of 25 columns x 80 ribs and a thickness of 8.5 ribs, and compression molded. 1 groove with 4 ribs deep
6 was cut along the longitudinal direction to obtain a superconducting cable 4 having an external cross section of 2 ratios x 7 ratios. This superconducting cable 4 was subjected to a bending test and a compression test, and the results shown in Table 2 were obtained.

From the bending test results shown in Table 2 1, it can be seen that the superconducting cable 5 of Example 1 having the honeycomb structure 9 has improved bending characteristics and flexibility compared to the superconducting cable 4 of Comparative Example 2. .

Furthermore, from the results of the compression test shown in Table 2, the superconducting cable 5 of Example 1 has a lower temperature than the superconducting cable 4 of Comparative Example 2.
It can be seen that the compressive strength is far superior.
Furthermore, since the weight of the superconducting cable 5 in Example 2 was half that of the superconducting cable 4 in Comparative Example 2, it can be seen that the strength per unit weight was also significantly improved. Furthermore, the amount of stabilizing material in the superconducting cable 5 in Example 2 is about 18 times the amount of niobium titanium, and in the superconducting cable 4 in Comparative Example 2, it takes about 23 times the amount of niobium titanium to obtain the same current capacity. It can be seen that the superconducting cable 5 according to the present invention is extremely superior both in terms of economy and economy. As explained above, the superconducting cable according to the present invention has remarkable effects such as being lightweight and having high cooling efficiency, excellent mechanical strength, and maneuverability due to the honeycomb structure provided therein. It is something that you have.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing a conventional superconducting cable made by alternately stacking flat composite superconducting materials and stabilizing materials, and Figure 2 is a perspective view of a conventional superconducting cable having cooling holes and cooling grooves. FIG. 3 is a perspective view showing a conventional superconducting cable in which a composite superconducting material constructed in a pipe is housed, and FIG. 4 is an exploded perspective view showing a superconducting cable according to the present invention. 5 is an enlarged sectional view showing the honeycomb cell in FIG. 4, FIG. 6 is an exploded perspective view showing another superconducting cable according to the present invention, and FIG. 7 is a hollow cylindrical shape according to the present invention. FIG. 8 is a sectional view showing a superconducting cable having a honeycomb structure in the frame of Comparative Example 1.
9 is a perspective view showing the constituent materials of the honeycomb structure, and FIG. 10 is a partial sectional view showing a superconducting cable provided inside the honeycomb structure according to the present invention by twisting it. A partially cutaway perspective view, Figure 11, is
3 is a perspective view showing a superconducting cable in Comparative Example 2. FIG.

1... Composite superconducting material, 2, 3... Flat plate, 4
, 5... superconducting cable, 6... hollow part,
7... Filler, 8, 8a, 8b, 88a... Honeycomb cell, 9... Honeycomb structure, 11, 111
...Flat plate, side plate, 12 ... Superconducting material, 14
...Frame body.

Sai 1 Zu Sai 2 Koji 3rd figure 5th figure figure V ★ Figure 6 off figure 8 years old Figure 9 Oh 0 box 11 fig.

Claims (1)

[Claims] 1. A superconducting cable consisting of a composite superconducting material, a stabilizing material, and a reinforcing material, including a honeycomb cell having a hollow portion made of one of the above constituent members, and one of the remaining two constituent members. The cable is characterized in that a honeycomb structure is provided inside the cable, the honeycomb structure comprising honeycomb cells formed by filling a frame made of any one of the above constituent members as a filler with one of the last remaining constituent members. superconducting cable.