JPH07201233A - High temperature superconducting power cable - Google Patents

Abstract

(57) [Summary] [Purpose] When mechanical stress or thermal stress is generated in the high-temperature superconducting conductor during the manufacture and use of the high-temperature superconducting power cable, the high-temperature superconducting conductor is susceptible to stress Provided is a high-temperature superconducting power cable capable of preventing the performance of the superconducting power cable from deteriorating. [Structure] A high-temperature superconducting power cable 20 has a plurality of tape-shaped high-temperature superconducting conductors 5 arranged on the outer peripheral surface of a copper tube 3 in which a coolant 2 such as liquid nitrogen flows. A semiconductive rubber layer 6 is provided so as to cover it. The kraft paper or the like is wrapped around the rubber layer 6 to form the insulating layer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature superconducting power cable having a stress relaxation layer for relaxing mechanical stress acting on a high temperature superconducting conductor.

[0002]

2. Description of the Related Art As shown in FIG. 2, a high temperature superconducting power cable is provided with a copper tube 3 forming a forward path of a refrigerant 2 in a central portion thereof, and a superconducting conductor 5 provided on an outer peripheral surface of the copper tube 3. The inner conductor layer 14, the insulating layer 8 and the outer conductor layer 9 are arranged in this order on the superconducting conductor 5. This copper tube 3 functions as a core. Further, the outer conductive layer 9 functions as a shielding layer. Further, the refrigerant 2 is provided outside the outer conductive layer 9 as the shielding layer.
The inner aluminum covering layer 10 is arranged with a gap to be a return path, and a heat insulating layer 11, an outer aluminum covering layer 12, and a corrosion-resistant layer 13 are formed on the outer side thereof.

As shown in a partially enlarged view of FIG. 3, the superconducting conductor 5 provided on the outer peripheral surface of the copper tube 3 has a tape-like shape extending in the cable axial direction, and a plurality of tape-like conductors 5 are provided.
Are arranged in the cable circumferential direction. An inner conductive layer 14, an insulating layer 8 and an outer conductive layer 9 are formed on the conductor 5.

By passing a refrigerant through the cable having such a structure to cool the high-temperature superconducting conductor 5 to a temperature below the critical temperature and bring it into a superconducting state, this cable functions as a high-temperature superconducting power cable.

[0005]

However, in the conventional high-temperature superconducting power cable, as shown in FIG. 3, the high-temperature superconducting conductor 5 is arranged outside the copper tube 3 at the time of manufacturing, and the inside is arranged outside the high-temperature superconducting conductor 5. Mechanical stress acts on the high-temperature superconducting conductor 5 when the superconducting power cable is manufactured by disposing the conducting layer 14, the insulating layer 8, the outer conducting layer 9 and the like. Further, when the high-temperature superconducting cable 1 is extended, mechanical stress acts, and when the high-temperature superconducting cable 1 is cooled, the high-temperature superconducting conductor 5 sandwiched between the inner conductive layer 14 and the core copper tube 3 is applied. Thermal stress acts. As a result, the superconducting characteristics of the high-temperature superconducting conductor 5, which is weak against such stress, deteriorates.

The present invention has been made in view of the above problems. By reducing the stress acting on the high temperature superconducting conductor during manufacturing and use, the superconducting characteristics of the high temperature superconducting conductor are deteriorated and the high temperature superconducting power cable is obtained. It is an object of the present invention to provide a high-temperature superconducting power cable capable of preventing the performance of the above from deteriorating.

[0007]

A high temperature superconducting power cable according to the present invention comprises a core layer in which a refrigerant flows,
It is characterized by having a high temperature superconducting conductor provided on the core layer, a stress relaxation layer provided on the high temperature superconducting conductor, and an insulating layer provided on the stress relaxation layer.

[0008]

In the present invention, since the stress relaxation layer is provided on the high temperature superconducting conductor provided on the core layer of the high temperature superconducting power cable, a layer such as an insulator layer is further provided thereon. At this time, even if a mechanical stress is applied to the high-temperature superconducting conductor, the stress is not relaxed by the stress relaxation layer and an excessive stress does not act on the superconducting conductor.

Also, when the high-temperature superconducting power cable is extended, the stress relaxation layer alleviates the mechanical stress acting on the high-temperature superconducting conductor sandwiched between the core layer and the insulating layer.

Further, even when the high temperature superconducting conductor is cooled to a temperature below the critical temperature in order to bring it into a superconducting state, even if there is a difference in the thermal contraction rate between the core layer and the insulating layer, the high temperature superconducting The thermal stress received by the conductor is relieved.

Therefore, according to the present invention, the deterioration of the superconducting characteristics of the superconducting conductor can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A high temperature superconducting power cable according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional view showing a high temperature superconducting power cable according to an embodiment of the present invention. This high-temperature superconducting power cable 20 has a copper tube 3 through which a coolant 2 such as liquid nitrogen flows, and a plurality of tape-shaped high-temperature superconducting conductors 5 are arranged on the outer peripheral surface of the copper tube 3. There is. The copper tube 3 functions as a core. A semiconductive rubber layer 6 is arranged on the conductor 5 so as to cover the high temperature superconducting conductor 5.
The rubber layer 6 is an EP-based semiconductive material, and has elasticity and serves as a stress relaxation layer. Further, an insulating layer 8 is formed by winding kraft paper around the rubber layer 6.

In the high-temperature superconducting power cable constructed as described above, the mechanical stress generated by wrapping the kraft paper in order to provide the insulating layer 8 at the time of manufacturing the cable is caused by the rubber layer 6 between the high-temperature superconducting conductor 5 and the rubber layer 6. Therefore, it does not act directly on the high temperature superconducting conductor 5. Further, when the high-temperature superconducting power cable 20 is extended and laid, and when the high-temperature superconducting power cable 20 is cooled with the refrigerant 2 such as liquid nitrogen or when the cooling is stopped to cause a temperature change, the high-temperature superconducting conductor 5 The mechanical stress or the thermal stress tends to act on the superconducting conductor 5, but the mechanical stress or the thermal stress is relaxed by the rubber layer 6 so that the superconducting conductor 5 is not overly stressed.

In this way, according to this embodiment, the stress acting on the high temperature superconducting conductor 5 can be relieved by the rubber layer 6, so that the deterioration of the superconducting characteristics of the high temperature superconducting conductor 5 can be prevented and the high temperature superconducting cable 20 can be prevented. Performance degradation can be avoided.

[0015]

According to the present invention, since the stress relaxation layer is disposed on the high temperature superconducting conductor provided on the core layer, the high temperature superconducting conductor sandwiched between the core layer and the insulating layer. It is possible to remarkably reduce the stress received by. Therefore, even if mechanical stress or thermal stress occurs during manufacturing and use,
It can be prevented from acting on the high-temperature superconducting conductor, deterioration of the superconducting properties of the high-temperature superconducting conductor can be avoided, and deterioration of the performance of the high-temperature superconducting power cable can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a part of a superconducting power cable according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional superconducting power cable.

FIG. 3 is a cross-sectional view showing a part of a conventional superconducting power cable.

[Explanation of symbols]

 1, 20; Superconducting power cable 2; Refrigerant 3; Copper tube 5; High-temperature superconducting conductor 6; EP-based semiconductive rubber layer 8; Insulating layer 9; Outer conducting layer 10; Inner aluminum covering layer 11; Thermal insulating layer 12; Outer aluminum layer 13; Corrosion resistant layer 14; Inner conductive layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Riki Iwasawa 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Ltd.

Claims (1)

[Claims] 1. A core layer through which a refrigerant flows, a high-temperature superconducting conductor provided on the core layer, a stress relaxation layer provided on the high-temperature superconducting conductor, and a stress relaxation layer on the stress relaxation layer. A high-temperature superconducting power cable having an insulating layer provided on the.