Reinforced superconducting wire, superconducting cable, superconducting coil and superconducting magnet

Abstract

A reinforced superconducting wire (1a) has a superconducting core strand (2) and a first cladding with a multitude of reinforcing strands (3). The reinforcing strands (3) are arranged around the circumferential surface of the superconducting core strand (2) in a non-crossing manner and are in contact with the core strand (2). The wire has a reinforcement for enhancing its mechanical properties against external stresses and for preventing diameter expansion during heat treatment. In addition to other advantages, such superconducting wire can be produced with an easy and low-cost production process.

Claims

1. Superconducting wire comprising: a superconducting core strand that has a circumferential surface, and a first cladding consisting essentially of at least one non-superconducting reinforcing strand, wherein the at least one reinforcing strand is arranged around the circumferential surface of the superconducting core strand in a non-crossing manner, and wherein the at least one reinforcing strand is in contact with the core strand.

2. Superconducting wire according to claim 1, wherein the at least one reinforcing strand of the first cladding is spirally wound around the circumferential surface of the superconducting core strand.

3. Superconducting wire according to claim 1, wherein the first cladding layer consists essentially of plural reinforcing strands arranged parallel to each other.

4. Superconducting wire according to claim 1, wherein the at least one reinforcing strand is aligned along the core strand at an angle to the core strand no greater than 10°.

5. Superconducting wire according to claim 4, wherein the at least one reinforcing strand is aligned along the core strand at an angle α=0° to the core strand.

6. Superconducting wire according to claim 1, wherein a diameter of the at least one reinforcing strand of the first cladding is less than a diameter of the superconducting strand.

7. Superconducting wire according to claim 1, further comprising at least one further cladding surrounding the first cladding, wherein the further cladding comprises at least one further strand which is oriented obliquely to the at least one reinforcing strand of the first cladding.

8. Superconducting wire according to claim 7, wherein the at least one further strand is oriented at an angle β to the superconducting core strand, with β>α.

9. Superconducting wire according to claim 7, wherein the first cladding comprises plural reinforcing strands of different cross sectional dimensions and/or the further cladding comprises plural further strands of different cross sectional dimensions.

10. Superconducting cable comprising at least two superconducting wires, each of the superconducting wires being configured according to claim 1.

11. Superconducting coil comprising a superconducting cable according to claim 10.

12. Superconducting coil comprising a superconducting wire according to claim 1.

13. Superconducting magnet comprising a superconducting coil according to claim 12.

14. Superconducting wire comprising: a superconducting core strand that has a circumferential surface, and a first cladding comprising at least one non-superconducting reinforcing strand, wherein the at least one reinforcing strand is arranged around the circumferential surface of the superconducting core strand in a non-crossing manner, wherein the at least one reinforcing strand is in contact with the core strand, and wherein the at least one reinforcing strand of the first cladding is made from carbon fibers.

15. Superconducting wire comprising: a superconducting core strand that has a circumferential surface, and a first cladding consisting essentially of a plurality of non-superconducting reinforcing strands, wherein the reinforcing strands are arranged around the circumferential surface of the superconducting core strand without overlapping one another and so as to each directly contact the core strand.

16. Method for producing a reinforced superconducting wire according to claim 1, comprising: a) producing the superconducting core strand, b) sheathing the core strand with the first cladding, wherein said sheathing comprises attaching a single one non-superconducting reinforcing strand or plural non-superconducting reinforcing strands to the superconducting core strand around the circumferential surface of the superconducting core strand in a non-crossing manner, wherein the single reinforcing strand is or the plural reinforcing strands are in contact with the core strand.

17. Method according to claim 16, wherein said sheathing comprises attaching plural carbon fiber reinforcing strands to the superconducting core strand.

18. Method according to claim 16, wherein the first cladding is formed by spirally winding the at least one reinforcing strand around the circumferential surface of the superconducting core strand.

19. Method according to claim 16, wherein the first cladding is formed by aligning the at least one reinforcing strand along the core strand at an angle α to the superconducting core strand no greater than 10°.

20. Method according to claim 16, further comprising: c) jacketing the circumferential surface of the first cladding with at least one further cladding, wherein the further cladding comprises at least one further strand.

21. Method according to claim 20, wherein the at least one further cladding is formed by twisting or braiding, or is woven of the at least one further strand over the first cladding.

22. Method according to claim 20, wherein the further cladding is formed by spirally winding the at least one further strand around the circumferential surface of the first cladding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective view of a superconducting wire according to the invention with a first cladding comprising reinforcement strands aligned parallel to the core strand and a second cladding with a spirally wound further strand.

(2) FIG. 2 shows a cross sectional view of the superconducting wire shown in FIG. 1.

(3) FIG. 3 shows a perspective view of a superconducting wire according to the invention with a first cladding comprising reinforcement strands aligned parallel to the core strand and a second cladding with braided further strands.

(4) FIG. 4 shows a cross sectional view of the superconducting wire shown in FIG. 3.

(5) FIG. 5 shows a perspective view of a superconducting wire according to the invention with a first cladding comprising reinforcement strands spirally wound around the core strand.

(6) FIG. 6 shows a cross sectional view of the superconducting wire shown in FIG. 5.

DETAILED DESCRIPTION

(7) FIG. 1 and FIG. 2 show a superconducting wire 1a with a core strand 2 (here: single solid core) surrounded by a multitude of thinner non-superconducting reinforcing strands 3. The reinforcing strands 3 form a first cladding, which is in direct contact with the surface of the core strand 2. The reinforcing strands 3 of the first cladding are parallel to the core strand 2, i.e. aligned with the core strand 2 at an angle α=0° and evenly distributed around the surface of the core strand. A further cladding (second cladding) is provided surrounding the first cladding and keeping the first cladding in place. The second cladding comprises a further strand 4 spirally wound around the first cladding. The further strand 4 of the second cladding and the core strand 2 confine an angle β near to 90°. If smaller angles β are chosen, more than one further strand is required to form the second cladding.

(8) FIG. 3 and FIG. 4 show another embodiment of the inventive superconducting wire. Instead of a spirally wound further strand 4, the second cladding comprises braided further strands 4′.

(9) FIG. 5 and FIG. 6 show another embodiment of the inventive superconducting wire 1c where a reinforcement strand 3 of the first cladding is spirally wound around the core strand 2. No second cladding is required to keep the first cladding in place.

(10) In order to tune the radial and longitudinal reinforcement, different cross sectional dimensions of the reinforcing strand(s) 3 of the first cladding and of the further strand(s) 4, 4′ of the further cladding can be chosen. FIG. 1 and FIG. 2 for example show an embodiment of the inventive superconducting wire with reinforcing strands having a larger diameter than the further strands.

(11) An aspect of the present invention, according to one formulation is to coat the superconducting core strand 2 with a reinforcement cladding in order to increase the ability of the superconducting wire 1a, 1b, 1c to resist forces acting, e.g., in a magnet. According to the invention, thin reinforcement strands 3 are distributed around the circumference of the core strand and are aligned along the core strand 2. To hold the reinforcement strands 3 of the first cladding in place, a second cladding of other thin strands 4, 4′ can be provided. In this case, the superconducting wire 1a, 1b, 1c is also resistant to radial compression. The reinforced superconducting wire 1a, 1b, 1c can be easily wound into coils, reacting at high temperatures and then impregnated, if required.

(12) The present invention improves the mechanical properties of superconducting wires and superconducting cables comprising a superconducting core strand vis-à-vis those known conventionally by sheathing them in accordance with the invention. Such superconducting wires and superconducting cables can be used, e.g., in magnetic or energy transportation applications (e.g. Rutherford cables with several numbers of strands or, in the other extreme, in the simplest form, a few twisted strands). The invention is used most advantageously when it comes to withstand forces, e.g. in cabling for energy transport due to the strong forces between the strands or when the conductor/cable is pulled for some reason.

(13) The inventive method allows the reinforcement to be matched/tuned in terms of strength of the reinforcement as well as of type of the reinforcing (longitudinal or radial) by selecting and combining respective materials and by choosing the alignment angle between superconducting strand and reinforcing strands.

LIST OF REFERENCE SIGNS

(14) 1a, 1b superconducting wire 2 superconducting core strand 3 reinforcement strands forming the first cladding 4 further strand forming the second cladding 4′ braided strands forming the second cladding

LIST OF LITERATURE

(15) [01] U.S. Pat. No. 6,534,718 B1 [02] K. Watanabe et al “Ag-sheathed Bi2Sr2CaCu2O8 square wire insulated with oxidized Hastelloy fiber braid” AIP Conference Proceedings 986, 439 (2008), [03] US 2014/0296077 [04] US 2001/0055780 A1 [05] CN203787146 U [06] U.S. Pat. No. 5,214,243 [07] U.S. Pat. No. 2,111,409 [08] U.S. Pat. No. 5,593,524 [09] U.S. Pat. No. 5,796,043 [10] CN1658343A