JP2012114230A - Superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable superconducting coil having a simple winding structure.SOLUTION: The superconducting coil comprises at least one first winding part 2a where one tape-shaped superconducting wire rod 2 is wound spirally, at least one second winding part 2b where one tape-shaped superconducting wire rod 2 is wound spirally in the direction opposite from that of the first winding part 2a and which is arranged on the axis concentric with the first winding part 2a, and a connection 4 which configures a series circuit by electrically connecting one first winding part 2a and one second winding part 2b sequentially so that magnetic moments generated in the first winding part 2a and second winding part 2b have the same direction during electrification.

Description

  The present invention relates to a superconducting coil made of a tape-shaped superconducting wire.

  Today, the development of superconducting wires has been actively conducted in Japan and overseas, and the length of superconducting wires has been dramatically increased. Among these, a high temperature superconducting wire having a superconducting layer formed on a metal substrate via an intermediate layer is called a second generation high temperature superconducting wire. This high-temperature superconducting wire has a tape shape due to its manufacturing method.

  Superconducting wire is expected to be applied to various devices by winding it around a winding frame and making it into a coil. Typical methods for winding a tape-shaped superconducting wire to form a cylindrical coil (solenoid coil) include “layer winding” and “pancake winding”.

  “Layer winding” is a method in which a wire is wound around a cylindrical shaft (winding frame), that is, the winding position is shifted in the axial direction every time the shaft is rotated, and the next turn is wound with the same radius of curvature. “Pancake winding” is a method of winding a wire in a spiral, that is, winding the next turn while shifting the winding position while increasing the radius of curvature.

  Pancake winding is a winding method often used for coiling a wire having a rectangular cross-sectional shape such as a tape shape or a flat wire. On the other hand, depending on the specifications of the device to which the coil is applied and the dimensions (inner diameter, outer diameter, axial length) of the coil, layer winding may be desired regardless of the shape of the wire.

  The above-mentioned high-temperature superconducting wire has a tape shape instead of a round wire because of its manufacturing method, and therefore, the bending direction at the time of coiling is restricted as compared with the conventional low-temperature superconducting wire. Specifically, flat-wise bending, which is the bending of the surface that becomes the width of the wire, can handle a relatively small radius of curvature, but it is difficult to perform edge-wise bending, which is the bending of the surface that becomes the thickness of the wire. is there.

  For this reason, when trying to layer-wrap the superconducting wire of the tape wire around a cylindrical winding frame, the wire is bent in the edgewise direction at the folded portion where one layer of the winding frame is completely wound from one end to the other and then transferred to the next layer. Therefore, there is a risk that the superconducting characteristics may be deteriorated by strain.

  Conventionally, a method has been disclosed in which an end of a cylindrical winding frame is deformed or a tape wire is stacked near the end of the cylinder to reduce edgewise distortion (see Patent Documents 1 and 2).

JP 2007-73623 A JP 2009-130274 A

  The above-described conventional method is not a little distorted, and is particularly remarkable when the diameter of the reel is small. For this reason, the superconducting coil in which the superconducting tape wire is layer-wound has a problem that distortion in the edgewise direction is applied and the superconducting characteristics are deteriorated.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a superconducting coil having a simple winding structure and high reliability.

  In order to solve the above-described problems, the superconducting coil according to the present invention includes at least one first winding portion in which a single tape-shaped superconducting wire is spirally wound, and a single tape-shaped superconducting wire. At least one second winding portion wound in a spiral shape opposite to the direction of the first winding portion and disposed on a concentric axis with the first winding portion; The first winding portion and the second winding portion are sequentially electrically connected so that the direction of the magnetic moment generated in one winding portion and the second winding portion is the same. And a connecting part that constitutes a series circuit.

  According to the superconducting coil according to the present invention, the winding structure is simple and the reliability can be enhanced.

It is the schematic which shows 1st Embodiment of the superconducting coil which concerns on this invention, (A) is the top view, (B) is AA arrow sectional drawing of FIG. 1 (A), (C) is FIG. Explanatory drawing which abbreviate | omitted the winding frame of (B). The external view of the superconducting coil as a comparative example. It is a figure which shows the modification of the superconducting coil in 1st Embodiment, (A) is the top view, (B) is BB arrow sectional drawing of FIG. 3 (A). It is a figure which shows 2nd Embodiment of the superconducting coil which concerns on this invention, (A) is the top view, (B) is CC sectional view taken on the line of FIG. 4 (A). It is a figure which shows the modification of the superconducting coil in 2nd Embodiment, (A) is the top view, (B) is DD sectional view taken on the line of FIG. 5 (A). It is the schematic which shows 3rd Embodiment of the superconducting coil which concerns on this invention, (A) is the top view, (B) is EE arrow sectional drawing of FIG. 6 (A).

  Embodiments of a superconducting coil according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic view showing a first embodiment of a superconducting coil according to the present invention. 1A is a plan view of the superconducting coil 1, FIG. 1B is a cross-sectional view taken along the line A-A in FIG. 1A, and FIG. 1C is a view in which the winding frame in FIG. 1B is omitted. It is.

  The superconducting coil 1 is a coil in which a superconducting wire 2 is spirally layered. The superconducting wire 2 is, for example, an oxide-based high-temperature superconducting wire, such as bismuth (for example, Bi2223 phase, Bi2212 phase), yttrium (for example, YBCO), thallium (Tl), or mercury (Hg). Used. In the superconducting wire 2, an intermediate layer and a superconducting layer are sequentially laminated on a metal substrate.

  The superconducting coil 1 has a first winding portion 2a and a second winding portion 2b having a diameter larger than that of the first winding portion 2a. The first winding portion 2a and the second winding portion 2b are made of different single superconducting wires, and are arranged on concentric axes.

  The first winding portion 2a and the second winding portion 2b are wound around, for example, cylindrical winding frames 3a and 3b, and the winding position is shifted in the axial direction every time the shaft goes around, and the next turn Are wound with the same radius of curvature. The first winding portion 2a is wound counterclockwise (CCW) from the upper end to the lower end in the figure. The second winding portion 2b is wound clockwise (CW) from the upper end to the lower end in the drawing. The arrow in the figure indicates the winding direction when the superconducting wire 2 is wound from the upper end.

  The winding frames 3a and 3b are preferably insulators in order to avoid short-circuits between turns of the winding portions, eddy currents, and magnetization.

  The first winding portion 2a and the second winding portion 2b are electrically connected by a conductive connecting portion 4 at or near the end of the superconducting wire 2 at the lower end position in the figure. That is, the first winding part 2 a and the second winding part 2 b constitute a series circuit by being connected to the connection part 4.

  For example, when the current flowing through the superconducting coil 1 configured as described above flows clockwise from the upper end of the second winding portion 2b to the lower end, the first current passes through the connection portion 4 provided at the lower end position. It flows to the winding part 2a. Since the first winding portion 2a and the second winding portion 2b have opposite winding directions, the current flows clockwise through the second winding portion 2b. As a result, the directions of the magnetic fields generated in the first winding portion 2a and the second winding portion 2b are equal.

  In the superconducting coil 1, by providing the connection portion 4, connection resistance is generated and Joule heat is generated. This heat generation is not preferable in a permanent current mode operation device or a conductive cooling device. However, in the case of a device that takes into account heat generation due to AC loss during AC operation or a device that is submerged and cooled in consideration of refrigerant consumption, the heat load on the refrigerant is small compared to the AC loss of the coil, and the connecting portion 4 The effect of heat load is reduced.

  Here, a superconducting coil that forms a two-layer winding with a single superconducting wire as a comparative example will be described.

  FIG. 2 is an external view of a superconducting coil 100 as a comparative example.

  Superconducting coil 100 is formed by winding a single layer of superconducting wire 101 around a multi-layer superconducting coil. In this superconducting coil 100, a folded portion 102 is formed that finishes winding one layer and moves to the next layer, and the superconducting wire 101 is distorted in the edgewise direction.

  On the other hand, since the superconducting coil 1 in the present embodiment is formed with a single superconducting wire 2 for each layer, there is no folded portion when the superconducting wire wound up to one end of the winding frame moves to the next layer, and the edge No distortion in the width direction occurs.

  For this reason, the superconducting coil 1 can have high reliability without deteriorating the superconducting characteristics. Further, the superconducting coil 1 can simplify the winding structure, and can realize cost reduction.

  Furthermore, when cooling the superconducting coil 1 by immersing it in a refrigerant, the surface of the superconducting wire 2 cannot be brought into direct contact with the refrigerant if the superconducting wire 2 is fixed using resin. On the other hand, since it is not necessary to use resin by maintaining the shape of the winding part using the winding frames 3a and 3b, the surface of the superconducting wire 2 can be brought into direct contact with the refrigerant, and the AC loss of the superconducting wire It is possible to efficiently transmit heat generated by the above to the refrigerant.

  The superconducting coil is not limited to a circular cross section perpendicular to the axis, but may be an oval shape shown in FIG.

  FIG. 3 is a view showing a modification of the superconducting coil in the first embodiment. 3A is a plan view of the superconducting coil 11, and FIG. 3B is a cross-sectional view taken along the line BB in FIG.

  The superconducting coil 11 has an elliptical shape (so-called racetrack shape) having a circular section 11a and a straight section 11b in cross-sectional shape, and has a second diameter larger than that of the first winding section 12a and the first winding section 12a. Winding part 12b. The first winding portion 12a and the second winding portion 12b are composed of different superconducting wires, respectively. For example, it is effective when applied to a device in which a superconducting coil having an oval shape instead of a circular shape such as a dipole magnet that deflects a charged particle beam by a magnetic field is desirable.

  Superconducting coils 1 and 11 need only have different winding directions in adjacent layers, and clockwise and counterclockwise rotation may be selected as appropriate. The same applies to the following embodiments.

[Second Embodiment]
FIG. 4 is a diagram showing a second embodiment of the superconducting coil according to the present invention. 4A is a plan view of the superconducting coil 21, and FIG. 4B is a cross-sectional view taken along the line CC in FIG. 4A.

  The superconducting coil 21 has a first winding portion 22a to a sixth winding portion 22f. The number of layers of the winding portion can be appropriately increased or decreased. The first winding portion 22a to the sixth winding portion 22f are arranged on the concentric shafts, and the diameters are sequentially increased. The first winding part 22a to the sixth winding part 22f are each made of a different superconducting wire. The first winding portion 22a to the sixth winding portion 22f are each wound around a cylindrical winding frame (not shown).

  The first winding portion 22a, the third winding portion 22c, and the fifth winding portion 22e are wound counterclockwise (CCW) from the upper end to the lower end in the drawing. The second winding portion 22b, the fourth winding portion 22d, and the sixth winding portion 22f are wound clockwise (CW) from the upper end to the lower end in the drawing. That is, in the superconducting coil 21, the first winding portion 22a to the sixth winding portion 22f wound counterclockwise and clockwise are alternately arranged from the inner diameter side toward the outer diameter side.

  The first winding portion 22a to the sixth winding portion 22f are alternated by connecting portions 24a to 24e in which the winding portion wound clockwise and the winding portion wound counterclockwise are conductive. Connected to. Specifically, the first winding portion 22a and the second winding portion 22b are electrically connected by the connection portion 24a at the lower end position in the figure. The second winding portion 22b and the third winding portion 22c are electrically connected in series by the connecting portion 24b at the upper end position in the figure. The third winding portion 22c and the fourth winding portion 22d are electrically connected in series by the connection portion 24c at the lower end position in the figure. The fourth winding portion 22d and the fifth winding portion 22e are electrically connected in series by the connecting portion 24d at the upper end position in the figure. The fifth winding portion 22e and the sixth winding portion 22f are electrically connected in series by the connecting portion 24e at the lower end position in the drawing.

  That is, the first winding portion 22a to the sixth winding portion 22f constitute a series circuit by being connected by the connection portions 24a to 24e.

  The superconducting coil 21 in the second embodiment can constitute a superconducting coil having a larger number of turns by arranging a plurality of winding portions in the radial direction in addition to the effect exhibited by the superconducting coil of the first embodiment.

  FIG. 5 is a view showing a modification of the superconducting coil in the second embodiment. 5A is a plan view of the superconducting coil 31, and FIG. 5B is a cross-sectional view taken along the line DD in FIG. 5A.

  The first winding portion 32a to the third winding portion 32c are wound counterclockwise (CCW) from the upper end to the lower end in the drawing. The fourth winding portion 32d to the sixth winding portion 32f are wound clockwise (CW) from the upper end to the lower end in the drawing. That is, in the superconducting coil 31, the first winding portion 32a to the third winding portion 32c, which are three (multiple) superconducting wires wound counterclockwise, are wound clockwise on the inner diameter side. The fourth winding portion 32d to the sixth winding portion 32f, which are three-row superconducting wires, are arranged on the outer diameter side.

  The first winding portion 32a to the third winding portion 32c are wound in parallel (in a bundled state) on one winding frame. The fourth winding portion 32d to the sixth winding portion 32f are wound in parallel with respect to one winding frame.

  The first winding portion 32a to the sixth winding portion 32f are alternately formed by connecting portions 34a to 34e in which the winding portion wound clockwise and the winding portion wound counterclockwise are conductive. Connected to. For example, the first winding portion 32a and the sixth winding portion 32f are electrically connected in series by the connection portion 34a at the lower end position in the figure. The sixth winding portion 32f and the second winding portion 32b are electrically connected in series by the connection portion 34b at the upper end position in the drawing. The second winding portion 32b and the fifth winding portion 32e are electrically connected in series by the connection portion 34c at the lower end position in the drawing. The fifth winding portion 32e and the third winding portion 32c are electrically connected in series by the connection portion 34d at the upper end position in the figure. The third winding portion 32c and the fourth winding portion 32d are electrically connected in series by the connection portion 34e at the lower end position in the drawing.

  That is, the first winding part 32a to the sixth winding part 32f constitute a series circuit by being connected by the connection parts 34a to 34e.

  The superconducting coil 31 has a plurality of layers (three in FIG. 5) of superconducting wires 32 wound in parallel in a clockwise direction and a counterclockwise direction to form a plurality of layers (six in FIG. 5) of superconducting coils 31. The number of winding frames can be reduced as compared with the superconducting coil 21 of FIG. The superconducting coil 31 can reduce the space occupied in the radial direction by the winding frame. For example, when the thickness of the winding frame is 20 mm, the thickness of the superconducting coil 21 in FIG. 4 occupied by the radial winding frame is 20 mm × 6, which is 120 mm. On the other hand, the superconducting coil 31 of FIG. 5 is 20 mm × 2 and becomes 40 mm, and the thickness in the radial direction can be reduced to about one third.

  Therefore, a compact superconducting coil with a small space occupied by the coil portion with respect to the generated magnetic field and a high space current density can be realized.

[Third Embodiment]
FIG. 6 is a schematic view showing a third embodiment of the superconducting coil according to the present invention. 6A is a plan view of the superconducting coil 41, and FIG. 6B is a cross-sectional view taken along the line EE in FIG. 6A. Moreover, since each winding part of the superconducting wire 42 of the superconducting coil 41 in the third embodiment is substantially the same as the superconducting coil 31 in FIG. 5, description thereof is omitted here.

  The superconducting coil 41 has a winding frame 43a for winding the first winding portion 42a to the third winding portion 42c and a winding frame 43b for winding the fourth winding portion 42d to the sixth winding portion 42f. The winding frames 43a and 43b have a spiral winding groove 45 on the surface on which the superconducting wire 42 is wound. The winding groove 45 has a width substantially equal to the width of the superconducting wire 42.

  The superconducting wire 42 is wound along the winding grooves 45 of the winding frames 43a and 43b, and the position of each winding portion of the superconducting coil 41 is maintained by the winding grooves 45. For this reason, the position of the superconducting wire 42 on the surface of the winding frames 43a and 43b can be maintained with high accuracy.

  Further, even when cooling and heating are repeated for the superconducting coil 41 or when an external force such as electromagnetic force is applied, the superconducting wire 42 can be fixed at a fixed position, and the performance of the superconducting coil 41 can be improved. Can be improved.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1, 11, 21, 31, 41 Superconducting coil 2, 32, 42 Superconducting wire 2a, 2b, 12a, 12b, 22a-22f, 32a-32f, 42a-42f Each winding part 3a, 3b, 43a, 43b Reel 4 , 24a-24e, 34a-34e, 44a-44e Connection part 45 Winding groove

Claims (7)

At least one first winding portion in which a single tape-shaped superconducting wire is spirally wound;
A strip of tape-shaped superconducting wire is wound in a spiral shape opposite to the direction of the first winding portion, and at least one second winding disposed on a concentric axis with the first winding portion. A line section;
One first winding portion and one second winding portion so that the directions of magnetic moments generated in the first winding portion and the second winding portion when energized are the same. And a connection part that constitutes a series circuit. A plurality of the first winding part and the second winding part, respectively,
The superconducting coil according to claim 1, wherein the first winding portion and the second winding portion are alternately arranged in a radial direction. A plurality of the first winding part and the second winding part, respectively,
The superconducting coil according to claim 1, wherein the plurality of second winding portions are disposed radially outward with respect to the plurality of first winding portions. The superconducting coil according to claim 1, further comprising a plurality of winding frames made of an insulator around which the first winding portion and the second winding portion are wound. The winding frame includes a spiral groove having a width corresponding to the width of the superconducting wire,
The superconducting coil according to claim 4, wherein the first winding portion and the second winding portion are wound around the winding frame along the groove. A plurality of the first winding part and the second winding part, respectively,
The plurality of second winding portions are arranged radially outward with respect to the plurality of first winding portions,
The plurality of first winding portions are wound in parallel with respect to one of the winding frames,
The superconducting coil according to claim 4, wherein the plurality of second winding portions are wound in parallel to the other winding frame. The superconducting coil according to claim 1, wherein the shape of a cross section perpendicular to the axis is a circle or an oval having an arc portion and a straight portion.

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