JPS63144761A - Superconducting winding - Google Patents

Abstract

PURPOSE:To improve cooling and insulating properties of a winding by winding a surface of superconductive wire with a tape made by providing a nonwoven fabric with longitudinal and lateral grooves and by heating said fabric to bring it to self-fusion-weld. CONSTITUTION:An insulating tape 3 with longitudinal and lateral grooves 2 composed of a nonwoven fabric 1 of polyester fiber is wound on to a superconducting wire 4 and then the obtained product is wound round a drum. After that, power is applied to said drum to heat the superconducting wire 4 to about 180 deg.C to cause self-fusion-weld of the fiber of said nonwoven fabric 1 to a surface of the superconducting wire 4 and form an insulated superconducting wire 5. Thus, a self-fusion-weld face 6 of said fiber adheres strongly to enable preventing the insulating tape 3 from easily peeling off from the superconducting wire 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a superconducting field winding used in a superconducting generator,
In particular, it relates to field windings with improved cooling performance.

[Conventional technology]

It is difficult to form a superconducting generator-ring channel in which superconducting wires are closely wound, for example.

Insulation is also a problem because there are almost no gaps between the conductors when the winding is tightly wound, but there is no cooling channel for liquid helium to flow, so the cooling performance is poor, and the superconducting field winding is difficult to maintain during transients caused by external disturbances. The line had the problem of quenching. For this reason, Japanese Unexamined Patent Application Publication No. 54-7
As shown in Publication No. 509, a semi-cured glass cloth tape impregnated with an epoxy resin and semi-cured is wound spirally on the surface of a superconducting wire at intervals of a certain width. Cooling channels were shaped and insulated between the conductors. In this way, a long spiral cooling channel is formed, the flow of liquid helium is poor, and the part where the semi-cure tape is bonded to the winding conductor is not cooled, so the cooling performance of the superconducting field winding is insufficient. In some cases, quenching occurred during transient periods. In addition, in terms of insulation, since the semi-cure tape is wrapped around the conductor at a certain width interval, the unwrapped parts of the semi-cure tape may come into contact with each other and cause a short circuit. In some cases, the superconducting field windings were quenched and burned out.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not sufficiently consider the cooling area and insulation of the directional single-turn conductor of the cooling channel inside the superconducting field winding, resulting in problems such as quenching of the superconducting field winding and short-circuit burnout during transients. there were.

An object of the present invention is to provide a superconducting field winding that improves the cooling performance and insulation properties of the winding and is free from quenching and short-circuit burnout.

[Means for solving problems]

That is, in the present invention, a heated wire mesh is applied to a nonwoven fabric made of polyester fiber or the like to form vertical and horizontal grooves, a tape is cut out from this nonwoven fabric, and the tape is hung halfway on the surface of a superconducting wire. After the superconducting wire is insulated and wound around a drum, the superconducting wire is heated by electricity to self-fuse the nonwoven tape. This insulated superconducting wire is shaped like a solenoid.

Alternatively, the wire is wound in a saddle shape and bound every few layers to strongly support the wire conductor so that it does not move due to electromagnetic force or the like.

By doing this, cooling channels are created inside the winding in two circumferential directions in the radial direction and in the axial direction, resulting in good cooling performance.Since the entire surface of the winding conductor is insulated, the winding conductor is not pulled by electromagnetic force, etc. There is no chance of a short circuit occurring if the capacitors meet.

[Effect]

In the present invention, a grooved tape made of polyester fiber or the like is used by winding it around a superconducting wire, but simply winding it causes the wire to loosen or come off during the winding process, making it uncomfortable.
However, if adhesive is applied to the conductor or tape, the tape will become clogged, or the adhesive will cover the surface of the conductor, so liquid helium will not come into direct contact with the conductor, resulting in poor cooling performance. If the tape is self-fused to the superconducting wire as in the present invention, the tape will not come undone, and the liquid helium will come into direct contact with the conductor in areas other than the areas where it is self-fused, so the cooling effect will be great. The tape may be made of either non-woven fabric or incorporated fabric, but coarse tape has a greater cooling effect. Cooling channels are formed in the radial, circumferential, and axial directions of the winding, making it easier for liquid helium to flow, improving cooling performance.

The depth of the tape groove is approximately 0.1 mm, but a groove of this depth is sufficient to eliminate winding loss that occurs during transition. Furthermore, since the entire surface of the superconducting wire is covered with this tape, short circuits do not occur between the winding conductors, and this is highly effective in terms of winding insulation.

〔Example〕

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1-6. Figure 2 shows a polyester fiber nonwoven fabric 1 used in the present invention.
An insulating tape 3 with vertical and horizontal grooves 2 is shown. The work of creating vertical and horizontal grooves 2 on the non-woven fabric is done using a 18 mm
This is done by pressing a wire mesh heated to around 0°C. The insulating tape 3 is made of a wide non-woven fabric with grooves made using this method.
Cut it out to a width of m. The depth of groove 2 varies depending on the thickness of the nonwoven fabric, but it is 0.10 ny for a nonwoven fabric with a thickness of 0.2 mm.
About n is possible. The groove width was 4W11.

Figure 3 shows the superconducting wire 4 wrapped with insulating tape 3 without being wrapped around a drum, and the drum being energized to separate the superconducting wire 1.
An example of an insulated superconducting wire 5 is shown in which the fibers of the nonwoven fabric 1 are self-fused to the surface of the superconducting wire by heating to about 80° C. The self-fusing surface 6 of the fibers is strongly adhered, and the insulating tape 3 is not easily peeled off from the superconducting wire 4. Although various heating methods can be used for self-fusion, the above method is effective.

FIG. 4 shows a saddle-shaped superconducting field winding 7 for a superconducting generator manufactured using the insulated superconducting wire 5 shown in FIG. 3. Fourth
FIG. 5 shows a cross section taken along the line v--v in the figure. An insulated superconducting wire 5 is tightly wound, a coil 9 is supported by a binding tape 8, and a saddle-shaped superconducting field winding 7 is formed.

A detail of a portion of the tightly wound winding of FIG. 5 is shown in FIG. Since the nonwoven fabric 1 that is self-fused to the superconducting wire 4 has coarse mesh between the fibers, liquid helium can easily enter and exit the nonwoven fabric 1, and the cooling performance of the superconducting wire 4 is very good. A radial cooling channel 10 is formed in the radial direction of the winding, a circumferential cooling channel 11 is formed, and an axial cooling channel 12a is formed in the axial direction. Furthermore, axial cooling channels 12b are formed at the four corners of the insulated superconducting wire 5. In this way, since many cooling channels are formed, the flow of liquid helium is good, and a superconducting field winding with good cooling performance can be obtained.

FIG. 6 shows the results of comparing the effects of this embodiment with the conventional example. The figure shows the relationship between the magnetic field and the winding current density, with the vertical axis representing the winding current density when the conventional example is set to 1.0, and the horizontal axis representing the magnetic field when the conventional example is set to 1.0. This is what is shown. As is clear from the figure, the characteristic P of the superconducting field winding of this example is much superior to the characteristic Q of the conventional example in terms of winding current density, and the characteristic R of the wire is similar. There is. That is, while the conventional superconducting field winding quenches when the winding current density is 1 per unit (P, U,), the superconducting field winding of this embodiment has a winding current density of 1.3 P, U, will cause quenching. The characteristics of the superconducting field winding of this example were improved in this way because
The superconducting wire is wound with a non-woven insulating tape with vertical and horizontal grooves, and self-fusion increases the area in which the superconducting wire comes into direct contact with liquid helium, and the radial 9-9 area between the wound conductors increases.
This is because by forming many cooling channels in the circumferential direction and the axial direction, liquid helium can easily flow between the winding conductors, greatly improving cooling performance.

In this example, polyester was used as the synthetic nonwoven fabric, but the same effect can be obtained by using polyimide, polyamide, or polyethylene.

In addition, in this example, non-woven insulating tape was used, but
Insulating tape interwoven with fibers may also be used.

The rigidity and cooling performance of the winding can be further improved. Ceramic tape 13 is vertical on both sides.

A horizontal groove 14 is provided and communicated by a through hole 15. This ceramic tape 13 is coated with adhesive and wound around the outer periphery of the superconducting wire to form an insulated superconducting wire, which is then wound to produce a saddle-shaped superconducting field winding.

FIG. 8 shows a portion of a cross section of a saddle-shaped superconducting field winding. Similar to the superconducting field winding of the present invention, the cooling channels include a radial cooling channel 16, a circumferential cooling channel 17. Axial cooling channel 18
a, 18b are formed.

Ceramics has high rigidity, so it is possible to minimize the movement of the winding wire, and it also has high thermal conductivity, making it effective for cold parts - many ring channels can be formed, resulting in stability with less quenching. It is possible to obtain superconducting field windings with high current densities.

c′ Effect of the invention] According to the present invention, the cooling performance of the superconducting field winding is improved, so even if there is minute movement of the winding conductor, quenching does not occur.
In addition, since the entire surface of the superconducting wire is covered with insulating tape, there is no short circuit between the winding conductors due to electromagnetic force, centrifugal force, etc., and the superconducting field winding has a highly stable high current density. A line is obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the superconducting field winding of the present invention;
FIG. 2 is a sectional view of a grooved insulating tape used in the superconducting field winding of the present invention, FIG. 3 is a perspective view of an insulated superconducting wire used in the superconducting field winding of the present invention, and FIG. A perspective view of a superconducting field winding, FIG. 5 is a sectional view taken along the line ■-■ in FIG. 4, and FIG. 6 is a coil current density and magnetic field of an embodiment of the superconducting field winding of the present invention and a conventional example Figure 7 is a perspective view of the ceramic tape used in the superconducting field winding of the one-step prior invention, and Figure 8 is a partial cross-sectional view of the superconducting field winding of the one-step prior invention. be. 1... Nonwoven fabric, 2... Groove, 3... Grooved insulation tape.

Claims (1)

[Claims] 1. A superconducting wire in which an insulated superconducting wire is wound with a fibrous tape wound around the surface of the superconducting wire, wherein the fibrous tape is made of polyester fiber, polyimide fiber, polyamide fiber, polyethylene fiber, etc. The fibrous tape is made of synthetic fibers, the fibrous tape is provided with grooves in the longitudinal and lateral directions, and the fibrous tape is wound around the surface of the bare or enamel-coated superconducting wire to create radial, circumferential and axial cooling channels. A superconducting winding characterized by forming a superconducting wire. 2. The superconducting winding according to claim 1, wherein the grooved insulating tape is self-fused to the superconducting wire. 3. In claim 1, a ceramic tape is used instead of the fibrous grooved insulating tape, vertical and horizontal grooves are provided on both sides of the ceramic tape, and the grooves communicate with each other. A superconducting winding wire characterized by: