JP3622185B2 - Cryogenic insulation tube and superconducting cable - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cryogenic heat insulating tube used for, for example, a superconducting cable and a superconducting cable using the same.
[0002]
[Prior art]
FIG. 2 is a side view showing a partial cross section of an essential part of an example of a conventional cryogenic heat insulating tube.
In the drawings, reference numeral 1 denotes an inner tube made of aluminum or the like with spiral waves in which a flow path 3 of a cryogenic refrigerant such as liquid nitrogen is formed, and a metal foil and a plastic film having a small radiation coefficient are laminated on the outer periphery thereof. A multilayer heat insulating material 4 is provided. Further, an outer tube 2 such as spirally corrugated aluminum having a spiral in the same direction as the inner tube 1 is provided on the outer side, and the space between the outer tube 2 and the inner tube 1 is evacuated. ing.
[0003]
[Problems to be solved by the invention]
In the above-mentioned conventional cryogenic heat insulating pipe, the inner and outer pipes have the same corrugated spiral direction. Therefore, if the heat insulating pipe is bent or if the inner and outer pipes are misaligned even if they are straight, A portion where g becomes narrower is generated, and the portion is generated in a spiral shape along the wavy pitch, so that the range becomes longer. For this reason, when the gap g becomes extremely narrow, the multilayer heat insulating material is pressed against the inner and outer pipes along the spiral pitch. As a result, there is a problem that the degree of adhesion between the multilayer heat insulating material and the inner and outer tubes is increased, the amount of heat entering from the outer tube due to heat conduction is increased, and the heat insulating performance is significantly deteriorated due to damage to the multilayer heat insulating material.
[0004]
[Means for Solving the Problems]
The present invention solves the above-mentioned problems, and provides a cryogenic heat insulating tube that suppresses the narrowing of the gap caused by bending of the heat insulating tube, misalignment of the core of the inner and outer tubes, and a superconducting cable using the same. The first feature thereof is a cryogenic heat insulating tube in which the direction of the corrugated spiral of the inner tube and the outer tube is reversed, and the second feature of the present invention is the cryogenic heat insulating tube. The superconducting cable has a superconducting cable core housed in the inner pipe.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view showing a partial cross section of a main part of a specific example in which a superconducting cable core is housed in a cryogenic heat insulating tube of the present invention to constitute a superconducting cable. In the drawing, the same reference numerals as those in FIG. 2 represent the same parts.
As shown in the drawing, in the cryogenic heat insulating tube of the present invention, the spiral-wound inner tube 1 that forms the refrigerant flow path 3 and the spiral-wound outer tube 2 provided outside thereof are The attached spiral direction is formed in the opposite direction, and the inner tube 1 and the outer tube 2 are evacuated to form a cryogenic heat insulating tube.
Further, a superconducting cable core 5 is housed in the inner tube 1 of the cryogenic heat insulating tube to constitute a superconducting cable.
[0006]
In the cryogenic heat insulation pipe of the present invention having the above-described configuration, the spiral direction of the corrugation of the inner and outer pipes is opposite, so that the spiral part intersects even if the core of the inner and outer pipes is displaced. As a result, the gap narrowing range can be kept small. As described above, since the gap is narrowed only at the portion where the spirals intersect, the increase in the amount of intrusion heat due to heat conduction is prevented, and the range in which the multilayer heat insulating material is damaged is reduced, and the deterioration of the heat insulating performance of the heat insulating pipe can be suppressed. it can.
Therefore, a superconducting cable using such a heat insulating tube is less likely to be deteriorated in heat insulating performance even when the cable is bent, and can maintain good performance.
[0007]
【The invention's effect】
As described above, according to the cryogenic heat insulating tube of the present invention, even if bending or misalignment of the inner and outer tubes occurs, it is possible to suppress a decrease in the heat insulating performance to a small extent, and superconductivity using the cryogenic heat insulating tube. The cable can maintain stable thermal insulation performance.
[Brief description of the drawings]
FIG. 1 is a side view showing a partial cross section of a main part of a specific example in which a superconducting cable core is housed in a cryogenic heat insulating tube of the present invention to constitute a superconducting cable.
FIG. 2 is a side view showing a partial cross section of a main part of an example of a conventional cryogenic heat insulating tube.
[Explanation of symbols]
1 Inner pipe 2 Outer pipe 3 Refrigerant flow path 4 Multi-layer insulation 5 Superconducting cable core

Claims (2)

A cryogenic heat insulating tube constructed by evacuating a spiral waved inner tube with a flow path for cryogenic refrigerant such as liquid nitrogen inside and a spiral waved outer tube provided outside it The cryogenic heat insulating tube according to claim 1, wherein the corrugated spiral direction of the inner tube and the outer tube is reversed. A superconducting cable, wherein a superconducting cable core is housed in the inner pipe of the cryogenic heat insulating pipe according to claim 1.

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