JP3074616B2 - Cooling structure of oxide superconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an oxide superconductor having a relatively high critical temperature.

[0002]

2. Description of the Related Art Since an oxide superconductor has a relatively high critical temperature, a superconducting state body can be produced by cooling with liquid nitrogen (boiling point -196 ° C.) without using expensive liquid helium (boiling point -269 ° C.). it can. Conventionally, when the superconductor structure is small, a direct cooling system has been adopted in which the superconductor is directly immersed in liquid nitrogen for cooling.

However, in this direct cooling method, when the superconductor structure becomes large, the thickness of the material increases in order to secure the rigidity of the base and the cooling vessel, the cooling efficiency decreases, the cooling area increases, and the liquid used increases. There is a problem that the amount of nitrogen increases and the cost increases.In addition, since the amount of heat escaping from the cold heat of liquid nitrogen is large, it is necessary to make the heat insulating structure compact unless expensive vacuum heat insulation is used to improve heat insulation. In addition, there is a problem that the cost increases because a large vacuum vessel is required, and the superconductor is opened to reduce a magnetic field trapped in the superconductor when cooling the superconductor. Although it is necessary to cool down toward the end, if the open end does not come to the upper part, there is a problem that cooling cannot be performed so as to reduce the trapping magnetic field.

[0004]

As a method of solving the problem of the direct cooling system, an indirect cooling system in which a coiled tube 2 is wound around a superconductor substrate 1 and cooled by a refrigerant as shown in FIG. 5 is conceivable. When the superconductor is enlarged, this indirect cooling method is more advantageous than the direct cooling method in terms of efficiency and cost.
Since the heat transfer area W between the base 1 and the flexible tube 2 is small, the cooling efficiency is poor, and since it is technically difficult to reduce the welding interval D between the flexible tubes 2, it is difficult to improve the cooling efficiency. Have a problem.

Further, when welding is performed after annealing of a superconductor, two steps of annealing and then welding of a flexible tube are required, and furthermore, the temperature is too high due to welding of the flexible tube so that the superconductor is not destroyed. In order to do so, it is necessary to accurately control the temperature of the low-temperature welding, which causes a problem of increasing the cost.

Further, in the case of annealing the superconductor after the welding of the coil, if the coil is welded with solder, there is a problem that the solder remelts due to the temperature at the time of annealing and the coil is detached. In some cases, re-annealing is performed in order to regenerate the solder. However, since the solder is re-melted due to a rise in the temperature during annealing and the snake tube comes off, the regeneration is impossible.

[0007] Further, since the strength of the solder or the low-temperature welded portion is low, the welded portion may peel off due to a heat cycle, leading to a decrease in cooling efficiency.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a cooling structure for an oxide superconductor which can improve the cooling efficiency and reduce the manufacturing cost.

[0009]

In order to achieve the above object, the present invention provides an oxide superconductor cooling structure comprising: a base; a superconducting film coated on one surface of the base; and the other of the base. is fixed similar welded to the surface, heat forming the superconducting film
And a flow path member formed of a material having a higher processing temperature melting point, the superconductor panel refrigerant flow path is formed between the substrate and the flow path member as a basic shape, a single or a plurality of superconductor panel It is characterized in that a superconductor is constituted by being connected and combined.

[0010]

[0011]

According to the present invention, a superconductor panel of a panel type has a basic shape, and a single superconductor panel or a plurality of superconductor panels are connected and combined to form a superconductor. Manufacturing costs can be reduced. Further, the following effects are obtained.

[0012] Compared with the direct cooling method, the supply amount of the refrigerant is small, and the effect is greater as the superconductor is made larger.

Since the heat transfer area is increased as compared with the indirect cooling method using a coiled pipe, the cooling efficiency is improved, the supply amount of the refrigerant can be reduced, and the problem of separation of the cooling flow path due to the heat cycle is solved. In addition, the temperature control of the low-temperature welding between the flexible tube and the base is not troublesome, and the production becomes easy. Further, it is possible to perform a compact insulation even with relatively large inexpensive insulation heat transfer Shiruberitsu other than vacuum insulation.

The rigidity is improved because the refrigerant flow passage and the base are integrated, and as a result, the thickness of the material functioning as the base when the superconductor is enlarged can be reduced, and the cooling efficiency can be reduced. Can be increased. Further, the amount of expensive nickel or the like used as a base material can be reduced.

When the oxide superconductor is annealed, the cooling structure is completed, so that the process can be shortened and the cost can be reduced.

In the case of the method by welding, the flow path member includes:
Since the base material of the superconductor or the material with a melting point higher than the heat treatment temperature for forming the superconducting film is used, the superconductor cannot be re-annealed by the indirect cooling method using a coiled tube manufactured using low-temperature welding. Reproduction becomes possible.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show one embodiment of a cooling structure for an oxide superconductor according to the present invention, wherein FIG. 1A is a plan view, and FIG. 1B is an enlarged sectional view taken along line BB of FIG. 1A. . The cooling structure of the oxide superconductor according to the present invention has a panel-type superconductor panel as a basic shape, and a single or a plurality of the superconductor panels are connected and combined to form a superconductor.

The superconductor panel 10 comprises a base 11, a superconducting film 12 coated on one surface of the base 11,
And a flow path member 13 having an uneven or corrugated shape which is fixed to the other surface by welding. A coolant flow path 14 is formed between the base 11 and the flow path member 13. The coolant channel 14 is designed with a channel pattern such that the coolant is supplied so that its rigidity can be secured and the surface of the base 11 can be uniformly cooled. In addition, 15 and 16 are inlet / outlet portions of the refrigerant.

The base member 11 and the flow path member 13 are welded in such a manner that the peripheral portion C of the flow path member 13 has a sealing property so that the refrigerant does not leak from the flow path member 13, for example, fillet welding. The portion D is formed by welding for integrating the base 11 and the flow path member 13, for example, by full welding. For the flow path member 13, the cooling efficiency is improved by using a material having a low thermal conductivity such as stainless steel, titanium, FRP, plastic, and polyurethane, but a material having a melting point higher than the heat treatment temperature for forming the superconducting film 12. It is preferable to use iron, nickel, titanium or the like. Examples of the material include a material used for the base 11 and a ferromagnetic material that helps to improve the magnetic shielding performance of the superconductor against a longitudinal magnetic field.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] Figure 2 shows an example in which the superconductor 20 from the superconductor panel 10, FIG. (A) is a plan view seen from above, FIG. (B) is a front view from the side. The superconductor panel 10 is formed in a cylindrical shape such that the flow path member 13 is on the outside. Various shapes such as a square shape other than the cylindrical shape are conceivable, and the case where the flow path member 13 is located inside is also conceivable.

FIG. 3 shows an example in which a superconductor 21 is constructed by combining a plurality of the above-described superconductor panels 10, and is a front view as viewed from the side. Superconductor panel 1 of basic shape
By combining a large number of zeros, a superconductor having a large area can be divided and cooled, so that the larger the cooling area, the better the cooling efficiency.

FIG. 4 is a perspective view showing an example in which the superconductor 21 is formed as a rectangular parallelepiped by combining a plurality of the superconductor panels 10 described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible. For example, not only the unitization of the superconductor panel but also the standardization of a heat insulating material having a shape that matches the coolant flow path pattern allows the superconductor cooling and heat insulating structures of various sizes to be manufactured at low cost.

[Brief description of the drawings]

1A and 1B show one embodiment of a cooling structure for an oxide superconductor according to the present invention, wherein FIG. 1A is a plan view, and FIG.
It is an expanded sectional view which follows a B line.

FIG. 2 shows an example in which a superconductor is formed from a superconductor panel. FIG. 2 (A) is a plan view seen from directly above, and FIG. 2 (B) is a front view seen from just beside.

FIG. 3 is a front view as viewed from the side, showing an example in which a superconductor is configured by combining a plurality of superconductor panels.

FIG. 4 is a perspective view showing an example in which a plurality of superconductor panels are combined to form a superconductor in a rectangular parallelepiped.

FIG. 5 is a cross-sectional view for explaining a problem of the present invention.

[Explanation of symbols]

10: superconducting panel, 11: base, 12: superconducting film,
13: flow path member 14: refrigerant flow path, 20, 21 ... superconductor

Continued on the front page (72) Inventor Shinichi Shibuya 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Noboru Ishikawa 2-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation In-house (72) Inventor Morino Hitio 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Sumio Mukai 1-2-3, Shibaura, Minato-ku, Tokyo Shimizu Corporation (56) References JP-A-64-13708 (JP, A) JP-A-52-25593 (JP, A) JP-A-6-69552 (JP, A) JP-A-2-162798 (JP, A) 52-108567 (JP, U) Japanese Utility Model Application Hei 2-95264 (JP, U)) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 39/00-39/04 H01L 39/14 -39/20 F25D 3/10 H05K 7/20 H05K 9/00

Claims (1)

(57) [Claims] And 1. A substrate, a superconducting film to be coated on one surface of said substrate, is fixed by welding to the other surface of the substrate, before
Serial and a flow path member formed of a material having a higher melting point than Netsusho sense the temperature for forming the superconducting film, the superconductor panel refrigerant flow path is formed between the substrate and the flow path member to its basic shape,
A cooling structure for an oxide superconductor, wherein a single or a plurality of the superconductor panels are connected and combined to form a superconductor.