JPS6024522B2 - superconducting conductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting conductor, and more particularly to a superconducting conductor having grooves through which a cooling medium passes when a superconducting coil is formed.

Generally, in large superconducting coils used in bubble chambers, discharge boxes, MHD generators, nuclear fusion reactors, energy storage devices, etc., safety, that is, the stability of the superconducting conductors that form the superconducting coil, is a priority because of their large size. Firstly, and secondly, in order to withstand strong electromagnetic force, a superconducting conductor coated with a large amount of normal conducting metal is used. The design of this type of superconducting conductor was developed by Z. J.J. This is usually done according to Stikly's theory of complete stabilization. However, the problem with designs that take seismic magnetic force and complete stability into consideration is that the effective current density of the superconducting coil decreases, resulting in an increase in the size and weight of the superconducting coil. As is well known, Joho Z. J.J. Stikly's complete stabilization theory is that multiple superconducting filaments are coated with a normal conducting metal, and even if the superconducting filaments transition to a normal conducting state for some reason, the current is transferred to the normal conducting metal, and the Joule heat generated there is suppressed. It was designed to quickly transfer the temperature from the surface of the normal conducting metal to the refrigerant, thereby keeping the temperature rise in the superconducting conductor below the critical temperature of the superconducting filament.

Therefore, the amount of normal conducting metal is required to be several tens of times that of the superconducting filament, and a corresponding amount of heat dissipation area is also required.
Roughly considering electromagnetic force resistance, tensile and compressive stresses act on superconducting conductors, and it is necessary to determine the amount of normal conductive metal to withstand these stresses. Furthermore, the heat dissipation area of a superconducting conductor strongly depends on the winding method, and usually a cold soot passage is provided in the coil winding portion, and a method such as inserting an insulating spacer has been used for this. However, it is difficult to insert an insulating spacer to provide a cold soot passage in the coil winding part, and generally, a groove or a protrusion is provided on the surface of the superconducting conductor to form a cold soot passage. This eliminates the need to insert an insulating spacer.

Such a superconducting conductor is shown in FIGS. 1a and 1b.

As shown in the figure, a superconducting conductor 1 is formed by covering a plurality of superconducting filaments 4 with a normal conducting metal 5. The one shown in FIG. 1a is an example in which a plurality of grooves 2 are provided on one side of the superconducting conductor 1, and these grooves 2 are used as coolant passages, and the one shown in FIG. This is an example in which a plurality of protrusions 3 are provided at intervals and the space between these protrusions 3 is used as a medium passage. As shown in the following, it is also possible to provide these grooves or protrusions 3 on both sides of the superconducting conductor 1.By the way, when applying the superconducting conductor 1 formed in this way to a large superconducting coil, it is necessary to It is necessary to design it to satisfy both conditions for stabilization.

However, in superconducting conductors that require especially high tensile strength, even if the complete stabilization condition is satisfied, the tensile strength of the superconducting conductor 1 is determined by the groove 2 part or the part without the protrusion 3, and the tensile strength is insufficient. There was something to do. The present invention has been made in view of the above points, and its purpose is to satisfy not only complete stabilization conditions but also tensile strength conditions even when the superconducting conductor has grooves, and to be compact. The object of the present invention is to provide a superconducting conductor that can be lightweight.

In the present invention, grooves formed on the side surfaces of a rectangular conductor formed by coating a plurality of superconducting filaments with a normal conductive metal are arranged in the longitudinal direction of the conductor so that the cross-sectional area of the conductor is always constant in the longitudinal direction. By tilting it, the intended purpose is achieved.

The present invention will be described below based on embodiments shown in the drawings.

An embodiment of the present invention is shown in FIGS. 2a and 2b.

As shown in the figure, in the superconducting conductor 11 of this embodiment, the plurality of grooves 12 provided on one surface of the superconducting conductor 11 are inclined in the longitudinal direction so that the cross-sectional area of the superconducting conductor 11 is always constant in the longitudinal direction. There is. In the case of this embodiment, the slope of the groove 12 is displaced by one pitch between its both ends.
It is also possible to form a groove in which the cross-sectional area of the conductor is made constant by displacing the conductor by a plurality of pitches. Next, the effects of the configuration of this embodiment will be explained in the third section.
This will be explained in comparison with the conventional configuration shown in Figures a and b'. now,
Assume that the superconducting conductor 11 shown in FIG. If the width d and the width t are the same for both the superconducting conductors of this embodiment and the conventional example, then the effective cross-sectional area ratio of the superconducting conductor t is ~ As is clear from Figure 2a and Figure 3a (the diagonal lines are From the ratio of the area of the untreated part)・10d■Word cover≦etc;@)＞・

Here, ■ is the oblique angle of the groove 12 in this embodiment.
Further, the effective area of the superconductor in contact with the refrigerant is larger in this embodiment than in the conventional case by (sin-1-1)b.d.p-1.

Therefore, the superconducting conductor 11 to which this embodiment is applied is superior in effective cross-section mirror and effective area in contact with the coolant compared to the conventional one.In other words, in order to have the same performance as the conventional superconducting conductor 1, 4. It is possible to reduce the weight of the mold and improve the effective current density. FIG. 4 shows another embodiment of the invention.

In the embodiment shown in the figure, grooves 22 are provided on opposite sides of a superconducting conductor 21, the grooves 22 being oblique in opposite directions. In this case as well, the structure of the groove 22 is such that the cross-sectional area of the conductor is constant along its longitudinal direction. In addition, the grooves 2 on both sides
Although the two pitches and phases are shown to be the same, they do not necessarily have to be the same. The configuration of this embodiment not only provides the same effects as the embodiments described above, but is also advantageous when the shape of the superconducting coil is complex. For example, in a part of a superconducting conductor wound around a superconducting coil, one groove is horizontal (
Even if the other groove becomes horizontal (perpendicular to the direction of gravity), the other groove will not become horizontal, allowing smooth flow of cold soot. In addition, when winding a superconducting conductor into a superconducting coil, the overlap between layers is good, and the grooves do not overlap parallel to each other, but always cross each other, which is advantageous against compressive stress. Become. According to the superconducting conductor of the present invention described above, the cross-sectional area of the conductor is always constant in the longitudinal direction. Since the cross-sectional area of the conductor is always constant in the longitudinal direction even if there are grooves, the tensile strength is the same everywhere in the longitudinal direction, and the grooves are inclined at zero angle. Therefore, the effective area in contact with the refrigerant is excellent, and the superconducting conductor can be made smaller and lighter under completely stable conditions.

[Brief explanation of the drawing]

1a and 1b are perspective views showing conventional superconducting conductors, and FIG. 2 b is a perspective view showing an embodiment of the superconducting conductor of the present invention,
FIG. 2a is a side view thereof, FIG. 3b is a perspective view of a conventional superconducting conductor, FIG. 3a is a side view thereof, and FIG. 4 is a perspective view showing another embodiment of the present invention. 1, 11, 21, 31... superconducting conductor, 2, 1
2, 22, 32...Groove, 4...Superconducting filament, 5...Normal conducting metal. Poly'2, 2, 3, and 3

Claims (1)

[Claims] 1. In a superconducting conductor having a groove on the side surface of a rectangular conductor formed by coating a plurality of superconducting filaments with a normal conducting metal, the groove has a cross-sectional area of the conductor that is always constant in the longitudinal direction. A superconducting conductor characterized by being inclined in the longitudinal direction of the conductor so that. 2. The superconductor according to claim 1, characterized in that a groove inclined in a direction opposite to the direction of the groove is provided on a surface of the superconducting conductor opposite to the surface on which the groove is provided. conductor.