JP2023074344A - Heat insulation multiple pipe for super conductivity power transmission, heat insulation multiple pipe laying device for super conductivity power transmission, heat insulation multiple pipe construction method for super conductivity power transmission, and superconductive cable construction method - Google Patents

Abstract

To provide a heat insulation multiple pipe for super conductivity power transmission, a heat insulation multiple pipe laying device for super conductivity power transmission, a heat insulation multiple pipe construction method for super conductivity power transmission, and a superconductive cable construction method capable of suppressing manufacturing costs, reducing pressure loss in vacuuming, and securing roundness of an inner pipe.SOLUTION: A heat insulation multiple pipe (1) for super conductivity power transmission into which a superconductive cable core (2) is inserted includes: an inner pipe (11), which is a straight pipe; an outer pipe (12), which is a straight pipe and disposed outside the inner pipe (11); a flow channel (FP2) of a cooling medium for cooling the superconductive cable core (2), which is formed inside the inner pipe (11); a heat resistant radiation layer (13) disposed on the outer surface of the inner pipe (11); and a plurality of heat insulation materials (14) disposed between the outer pipe (12) and the heat resistant radiation layer (13), which is arranged in an axial direction of the inner pipe (11) at a predetermined interval (D). The predetermined interval (D) is larger than 50 mm and equal to or smaller than 180 mm.SELECTED DRAWING: Figure 1

Description

The present invention relates to a superconducting thermal insulation multiplex pipe, a superconducting thermal insulation multiplex pipe laying apparatus, a construction method for a superconducting thermal insulation multiplex pipe, and a superconducting cable construction method.

A superconducting cable using a superconducting conductor as a conductor through which current flows is known. Superconductivity is a phenomenon in which the electrical resistance of metals and alloys becomes zero below their inherent transition temperature. A superconducting cable can pass a large current even if its cross-sectional area is small, so that power transmission equipment can be downsized and power transmission efficiency can be improved. In order to maintain the superconducting state of the superconducting conductor when a current is passed through the superconducting cable, the superconducting conductor must always be cooled to below the transition temperature. For example, the superconducting conductor is cooled by flowing a coolant (such as liquid nitrogen) inside the superconducting cable. In addition, since it is necessary to prevent heat from entering the superconducting conductor from the outside of the superconducting cable, the superconducting cable is often composed of a superconducting cable core made by twisting superconducting wires together and a heat-insulating multiple tube.

Patent Document 1 discloses a superconducting power transmission heat insulation multiplex tube into which a superconducting cable core is inserted, comprising an inner tube that is a straight tube, an outer tube that is a straight tube and is arranged outside the inner tube, and an inner tube. A heat-resistant radiation layer provided on the outer surface, and a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube, , a superconducting power transmission heat insulation multiplex tube in which a coolant flow path for cooling a superconducting cable core is formed. According to Patent Document 1, it is desirable that the gap between the plurality of heat insulating materials is 50 mm or less. Regarding the construction method, the superconducting heat insulation multiple pipe for superconducting power transmission or the superconducting cable having a superconducting cable core to be inserted into the superconducting heat insulation multiple pipe for superconducting power transmission or the superconducting heat insulation multiple pipe for superconducting power transmission or the superconducting cable is bent. We propose a transporting process and a process of bending the superconducting cable straight back after transporting.

Japanese Patent No. 6751826

For example, when a superconducting cable is used for electric power transmission or railways, a long superconducting cable is required. Considering the ease of manufacturing the superconducting cable and the workability at the cable laying site, it is desirable that the heat-insulating multiplex tube used for the superconducting cable is also manufactured in a long length at a factory. In this case, the heat insulating multi-layered pipe is bent and wound around a drum before being transported from the factory. Also, at the construction site, the heat insulating multi-layer pipe wound around the drum is bent back straight.

In the superconducting power transmission heat insulating multiple tube according to Patent Document 1, the number of heat insulating materials to be arranged is increased because the distance between the heat insulating materials is set to 50 mm or less. As a result, there are problems such as an increase in the manufacturing cost of the heat insulating multiple tube and an increase in pressure loss when the space between the inner tube and the outer tube is evacuated to form the heat insulating layer. In addition, if the distance between the heat insulating materials is too large, the heat insulating multi-layer tube will buckle during bending and unbending, making it impossible to insert the superconducting cable. Therefore, an optimum interval between the heat insulating materials is required so that the heat insulating multiple pipes do not buckle and the roundness of the inner pipes can be ensured. The circularity is the ratio of the major axis to the minor axis of the inner tube or the outer tube ((minor axis/major axis)×100(%)).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to provide a heat insulating multiple pipe for superconducting power transmission, a heat insulating multiple pipe laying device for superconducting power transmission, a construction method for a heat insulating multiple pipe for superconducting power transmission, and a construction method for a superconducting cable.

The inventor of the present invention has made intensive studies to solve the above-described problems. As a result, the present inventor arranged the heat insulating materials in the axial direction of the inner pipe at intervals of more than 50 mm and not more than 180 mm, and subjected the heat insulating multiple pipe to bending, unbending, and flattening. I found

The present invention has been made in view of the above findings. The gist of the present invention employs the following means.
(1) A superconducting power transmission heat insulation multiplex tube according to an embodiment of the present invention is a superconducting power transmission heat insulation multiplex tube into which a superconducting cable core is inserted,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
The predetermined distance is more than 50 mm and less than or equal to 180 mm.
(2) In (1) above,
The predetermined distance may be greater than 50 mm and less than or equal to 140 mm.
(3) In (1) or (2) above,
The predetermined interval may be an interval corresponding to a flattening device for increasing the roundness of the heat insulating multiple tube for superconducting power transmission.
(4) In (3) above,
The flatness correction device includes a plurality of rollers,
The predetermined interval may correspond to the interval between the plurality of rollers.
(5) In (4) above,
The predetermined interval may be set such that the plurality of rollers and the two heat insulators overlap each other when viewed along the first direction.
(6) In (4) above,
The intervals between the plurality of rollers may be set such that the plurality of rollers and the two heat insulators overlap each other when viewed along the first direction.
(7) A superconducting power transmission thermal insulation multiplex pipe laying device according to an embodiment of the present invention,
1. A superconducting power transmission insulation multiplex pipe laying device including a superconducting power transmission insulation multiplex pipe into which a superconducting cable core is inserted and a flattening device for increasing the roundness of the superconducting power transmission insulation multiplex pipe,
The heat insulating multiple tube for superconducting power transmission,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
The flattening correction device is in contact with the outer tube.
(8) A method for constructing a superconducting heat-insulating multiple pipe for power transmission according to an embodiment of the present invention includes:
The method for constructing a heat insulating multiple pipe for superconducting power transmission according to any one of (2) to (6) above,
a bending step of bending the superconducting power transmission heat insulating multiple tube;
a bending-back step of bending back the heat-insulating multiple pipe for superconducting power transmission bent in the bending step;
A flattening step of increasing the roundness of the superconducting power transmission heat insulating multi-pipe bent back in the flattening step by the flattening device;
Prepare.
(9) A superconducting cable construction method according to an embodiment of the present invention includes:
A superconducting cable construction method including the superconducting power transmission thermal insulation multiplex tube according to any one of the above (2) to (6) and a superconducting cable core to be inserted into the superconducting power transmission thermal insulation multiplex tube. ,
a bending step of bending the superconducting cable;
a bending-back step of bending back the superconducting cable bent in the bending step;
A flattening correction step of increasing the roundness of the superconducting cable bent back in the unbending step by the flattening correction device;
Prepare.

INDUSTRIAL APPLICABILITY According to the present invention, a superconducting power transmission heat insulation multiple tube and a superconducting power transmission heat insulation that can suppress manufacturing costs, reduce pressure loss during vacuuming, and further ensure the roundness of the inner tube. It is possible to provide a multi-pipe laying apparatus, a method for laying a superconducting heat insulating multi-pipe for power transmission, and a method for laying a superconducting cable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of a superconducting power transmission heat insulating multiplex tube according to an embodiment of the present invention; It is a side view which shows an example of the outline|summary of a flat correction apparatus. 2B is a front view of FIG. 2A; FIG. 4 is a table showing an example of measurement results of the roundness of the inner tube of the heat-insulating multiplex tube for superconducting power transmission according to the present embodiment. 4 is a graph showing an example of the average value of the roundness of the inner tube of the heat insulating multiplex tube for superconducting power transmission according to the present embodiment. 1 is a schematic diagram showing an example of a side surface of a superconducting power transmission heat insulating multiple pipe laying apparatus according to the present embodiment; FIG. FIG. 2 is a block diagram showing an example of a method for constructing the superconducting power transmission heat insulating multiple pipe according to the present embodiment. It is a block diagram which shows an example of the construction method of the superconducting cable which concerns on this embodiment.

A heat insulating multiple tube 1 for superconducting power transmission according to one embodiment of the present invention will be described with reference to the drawings. In the following description, common constituent elements may be given the same reference numerals, and redundant description thereof may be omitted. In the following description, the axial direction (longitudinal direction) of the superconducting power transmission heat insulation multiple tube 1 is the X direction, the depth direction of the paper surface of FIG. 1 is the Y direction, and the direction perpendicular to both the X and Y directions is the Z direction. sometimes referred to as

FIG. 1 is a cross-sectional view showing an example of a superconducting power transmission heat insulation multiplex tube 1 (hereinafter also simply referred to as heat insulation multiplex tube 1) according to the present embodiment. A superconducting cable core 2 is inserted through the heat insulating multiple tube 1 . A superconducting cable C is formed by the heat insulating multiple tube 1 and the superconducting cable core 2 . The superconducting cable C is long (for example, about 450 m) and used for electric power transmission and railways, for example.

The superconducting cable core 2 includes a corrugated tube 21 and superconducting conductors 22 provided outside the corrugated tube 21 . The superconducting conductor 22 is formed by laminating a thermal insulating layer 23, a superconducting layer 24, an electrical insulating layer 25, a shield superconducting layer 26, an electrical insulating layer 27, and a conductor protective layer 28 in this order. It is formed. The structure of the superconducting cable core 2 is not limited to this, and a known superconducting cable core 2 can be used.

Inside the corrugated tube 21, a first flow path FP1 is formed through which a coolant for cooling the superconducting cable core 2 flows. Liquid nitrogen, for example, is used as this coolant.

The thermal insulation layer 23 thermally insulates between the corrugated tube 21 and the superconducting conductor 22 . A current as a transmission current flows through the superconducting layer 24 . Electrical insulation layer 25 provides electrical insulation between superconducting layer 24 and shield superconducting layer 26 . A current flows through the shield superconducting layer 26 as a shield current. The electrical insulating layer 27 electrically insulates the superconducting conductor 22 from the outside. The conductor protective layer 28 mechanically protects the superconducting conductor 22 from the outside.

The heat insulating multiple tube 1 includes an inner tube 11 , an outer tube 12 , a heat resistant radiation layer 13 and a plurality of heat insulating materials 14 .

The inner tube 11 is cylindrical and is a straight tube that is not corrugated or corrugated. That is, the inner and outer surfaces of the inner tube 11 are smooth. Thereby, the pressure loss when the coolant flows inside can be reduced. A superconducting cable core 2 is inserted through the inner tube 11 . A gap is formed between the superconducting cable core 2 and the inner tube 11 . The inner tube 11 is made of stainless steel. For example, the material of the inner tube 11 is appropriately selected from SUS316, SUS316L, SUS304L, SUS304, and the like. The inner tube 11 has, for example, an outer diameter of 60.5 mm and a thickness of 2.0 mm.

A gap between the superconducting cable core 2 and the inner tube 11 is formed with a second flow path FP2 through which a coolant for cooling the superconducting cable core 2 flows. Further, as described above, the first flow path FP1 is formed inside the corrugated pipe 21 . The first flow path FP1 is used, for example, as an outward path through which a coolant supplied from a cooling device (not shown) flows from one end of the superconducting cable C to the other end. The second flow path FP2 is used, for example, as a return path for the coolant discharged from the other end of the superconducting cable C to flow back to the cooling device from the other end of the superconducting cable C toward one end. The coolant from the cooling device is supplied to one end of the superconducting cable C in a compressed state by a pump (not shown), thereby flowing through the first flow path FP1 and the second flow path FP2.

The outer tube 12 is cylindrical and is a straight tube that is not corrugated or corrugated. That is, the inner and outer surfaces of the outer tube 12 are smooth. The outer tube 12 is provided outside the inner tube 11 . A gap is formed between the inner tube 11 and the outer tube 12 . The outer tube 12 is made of stainless steel. For example, the material of the outer tube 12 is appropriately selected from SUS316, SUS316L, SUS304L, SUS304, and the like. The outer tube 12 has, for example, an outer diameter of 76.3 mm and a thickness of 2.0 mm.

A heat-resistant radiation layer 13 is provided on the outer surface of the inner tube 11 . The heat-resistant radiation layer 13 is provided over the entire length of the inner tube 11 . The heat-resistant radiation layer 13 is provided so as to cover the entire outer surface of the inner tube 11 . The heat-resistant radiation layer 13 has a thickness of 2 mm, for example. The heat-resistant radiation layer 13 is formed, for example, by winding super insulation around the inner tube 11 multiple times. Super insulation is a multi-layer heat insulating material having a structure in which, for example, a resin film on which aluminum is vapor-deposited and a polyester net are laminated. Super insulation suppresses the entry of radiant heat from the outside. That is, the heat-resistant radiation layer 13 suppresses the transmission of radiant heat from the outer tube 12 side to the inner tube 11 side, and prevents heat from entering the superconducting cable core 2 from the outside of the heat insulating multiplex tube 1 .

A heat insulating material 14 is provided between the heat-resistant radiation layer 13 and the outer tube 12 . The heat insulating material 14 is cylindrical. The heat insulating material 14 is arranged between the cylindrical inner tube 11 and the outer tube 12 over the entire circumference. A plurality of heat insulating materials 14 are intermittently arranged at predetermined intervals D in the axial direction (X direction) of the inner tube 11 . The predetermined interval D is the "insulating material installation interval" in FIG.
The plurality of heat insulating materials 14 are arranged at intervals of more than 50 mm (more than 50 mm) and less than or equal to 180 mm. The inventors of the present application have found that if the distance between the rotation axis of the roller 41A and the rotation axis of the roller 41B is set so that at least two heat insulating materials 14 are positioned in this distance, the heat insulating multi-layer tube 1 can be flattened. The inventors have found that by doing so, the inner tube 11 can be obtained with good roundness. As a result, even if the plurality of heat insulating materials 14 are arranged at intervals of more than 50 mm and at most 180 mm, as long as at least two heat insulating materials 14 are positioned at this interval, the roundness of the inner tube 11 is good. A tube 1 is obtained. More preferably, the distance between the plurality of heat insulating materials 14 exceeds 120 mm. More preferably, the distance between the plurality of heat insulating materials 14 is 140 mm or less.
A heat insulating material 14 is provided on the outer surface of the heat-resistant radiation layer 13 . A gap is formed between the heat insulating material 14 and the outer tube 12 . The width (length in the axial direction) of the heat insulating material 14 is preferably 19 mm or more and 50 mm or less. By setting the width of the heat insulating material 14 to 19 mm or more and 50 mm or less, it is possible to ensure the bending workability of the heat insulating multiple tube 1 . More preferably, the width of the heat insulating material 14 is 40 mm or more. The thickness of the heat insulating material 14 is, for example, 3 mm.

The heat insulating material 14 is formed with vent holes or grooves (not shown) penetrating in the axial direction. For example, the vents are formed to radially penetrate the heat insulating material 14 . That is, the ventilation holes extend from the inner peripheral surface to the outer peripheral surface of the cylindrical heat insulating material 14 . In this case, the heat insulating material 14 has a C-shaped cross section perpendicular to the axial direction. Since the length of the ventilation holes in the circumferential direction is about 5% of the total length of the heat insulating material 14 in the circumferential direction, which is sufficiently small, the heat insulating material 14 can be regarded as having a cylindrical shape.

The heat insulating material 14 may be made of, for example, fluorine resin (polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene) or glass fiber reinforced plastic obtained by adding fibrous filler to fluorine resin. . Alternatively, it is desirable to use glass fiber heat insulating paper to which silica airgel is added. In addition, the material of the heat insulating material 14 is not limited to this. For example, the heat insulating material 14 may be formed by winding super insulation around the heat-resistant radiation layer 13 multiple times.
By using the heat insulating material 14 in this manner, heat conduction between the inner tube 11 and the outer tube 12 can be suppressed.

A vacuum heat insulating portion 15 is formed between the plurality of heat insulating materials 14 and the outer tube 12 and between the heat-resistant radiation layer 13 and the outer tube 12 . That is, when the heat-insulating multiple tube 1 is viewed in cross-section along the axial direction, the heat-insulating material 14 and the vacuum heat-insulating portion 15 are placed between the heat-resistant radiation layer 13 and the outer tube 12, and the vacuum heat-insulating portion 15 extends in the axial direction. They are provided alternately. The vacuum heat insulating portion 15 is formed by drawing a vacuum between the inner tube 11 and the outer tube 12 . The air between the inner tube 11 and the outer tube 12 is evacuated through the gaps between the heat insulating materials 14 and the outer tube 12, the gaps between the heat insulating materials 14, and the ventilation holes formed in the heat insulating materials 14. Alternatively, it is carried out by discharging to the outside through a groove. The heat insulation material 14 and the vacuum heat insulation portion 15 suppress heat conduction from the outer tube 12 to the inner tube 11 , thereby preventing heat from entering the superconducting cable core 2 from the outside of the heat insulating multi-layer tube 1 .

In this embodiment, the plurality of heat insulating materials 14 function as materials for transmitting bending stress from the outer tube 12 to the inner tube 11 when the heat insulating multi-layer tube 1 is subjected to bending and unbending. The plurality of heat insulating materials 14 not only smoothly transmit the bending stress from the outer tube 12 to the inner tube 11, but also contribute to maintaining the circularity of the inner tube 11 after bending back.

According to the superconducting power transmission heat insulating multiple pipe 1 according to the present embodiment, the heat insulating materials 14 are arranged at intervals of more than 50 mm and 180 mm or less, so that the quantity of the heat insulating materials 14 can be reduced and the manufacturing cost can be suppressed. In addition, the circularity of the inner tube 11 can be ensured. That is, if the heat insulating materials are arranged at intervals of 50 mm or less, the number of the heat insulating materials 14 becomes too large, which increases the manufacturing cost and may adversely affect the evacuation. On the other hand, if the heat insulating materials are arranged at an interval of more than 180 mm, the distance between the heat insulating materials becomes too large when the multiple pipe is bent back, and the deformation at the place where the heat insulating material 14 is absent becomes too large. There is a possibility that the degree cannot be guaranteed.
Further, since the inner tube 11 is a straight tube, the inner surface of the inner tube 11 is smooth, and the pressure loss of the refrigerant in the second flow path FP2 formed inside the inner tube 11 can be reduced.

FIG. 2A is a side view showing an example of the outline of the flatness correction device 40. FIG. FIG. 2A shows the heat insulating material 14 provided inside the outer tube 12 for the following explanation. FIG. 2B is a front view of FIG. 2A. The heat insulating multiple tube 1 is in contact with the flattening device 40 . The flattening device 40 is a device for increasing the roundness of the heat insulation multi-pipe 1 . A flattening device is used, for example, to increase the roundness of a multi-pipe wound on a reel after the multi-pipe is unwound. The predetermined interval D between the plurality of heat insulating materials 14 described above is an interval corresponding to the flattening correction device 40 . The predetermined interval D of the heat insulating material 14 depends on the flattening correction device 40 .

The flatness correction device 40 includes a plurality of rollers 41A, 41B, 41C. As shown in FIGS. 2A and 2B, the flattening device 40 is in contact with the outer tube 12 of the heat insulating multi-layer tube 1 . The two rollers 41A and 41B are arranged side by side on the same plane (the XZ plane in FIG. 2A) passing through the axis of the heat insulating multiple tube 1. As shown in FIG. The roller 41A and the roller 41B are arranged with an interval therebetween. For example, the distance between the roller rotation axes of roller 41A and roller 41B in the X direction is 400 mm. The roller 41C is arranged on the same plane as the rollers 41A and 41B on the opposite side of the heat insulating multiple tube 1. As shown in FIG. The roller 41C is preferably arranged at an intermediate position between the rollers 41A and 41B in the X direction. The distance between the roller rotation axes of roller 41C and roller 41A or roller 41B in the X direction is 200 mm.
In the example shown in FIGS. 2A and 2B, a plurality of rollers 41A, 41B, and 41C are arranged in the vertical direction (Z direction), but the present invention is not limited to this configuration. , etc., may be arranged in other directions.

As shown in FIG. 2B, rollers 41A, 41B, 41C are grooved rollers. In the front view shown in FIG. 2B, the substantially circular groove formed by the rollers 41A, 41B and the roller 41C corresponds to the outer diameter of the heat insulating multi-layer tube 1. As shown in FIG. The rollers 41A, 41B and the roller 41C are arranged so as to sandwich the heat insulating multiple tube 1 therebetween.
Although three rollers 41A, 41B, and 41C are shown in FIG. 2A, the number of rollers is not limited to three. The rollers are arranged on both sides of the heat-insulating multi-pipe because the rollers sandwich the heat-insulating multi-pipe 1 from both sides.

The predetermined distance D depends on the distance between the rollers 41A, 41B, 41C. That is, the preferred predetermined interval D is determined by the interval between the rollers 41A and 41B and the interval between the rollers 41A and 41C (or the rollers 41B and 41C). In this embodiment, the circularity of the inner tube 11 can be ensured by setting the predetermined distance D to be more than 50 mm and 180 mm or less.
For example, in this embodiment, the width (length in the X direction) of the heat insulating material is 40 mm. for that reason,
As described above, when the distance between the roller rotation axes of roller 41C and roller 41A (or roller 41B) is 200 mm, even if the predetermined interval D is 140 mm, considering the width of the heat insulating material of 40 mm, At least one heat insulating material is always arranged between the roller 41C and the roller 41A.

A flattening device 40 having a plurality of rollers 41A, 41B, and 41C can flatten the heat-insulating multiple tube 1 . That is, even if the multiplex tube unwound from the reel has a flattened shape in the Z direction (first direction), it is possible to correct the flattened shape (by slightly crushing it in the Z direction) to make it closer to a perfect circle. can. At this time, it can be said that the Z direction is the direction for correcting the flatness of the multi-pipe.

The predetermined interval D is set so that the plurality of rollers 41A, 41B, 41C and the two heat insulating materials 14 overlap each other when viewed along the first direction (Z direction).

The intervals between the plurality of rollers 41A, 41B, 41C are set so that the plurality of rollers 41A, 41B, 41C and the two heat insulating materials 14 overlap each other when viewed along the first direction (Z direction). More specifically, the distance between the rotation axis of roller 41A and the rotation axis of roller 41B is set so that at least two heat insulators 14 are positioned in this distance. That is, in this embodiment, two heat insulating materials are arranged between the plurality of rollers by adjusting the distance between the heat insulating materials and the distance between the plurality of rollers.

The outer diameter and inner diameter of each of the three rollers 41A, 41B, 41C can be varied as long as at least two heat insulators 14 are positioned between the rotation axis of the roller 41A and the rotation axis of the roller 41B. value can be adopted.

Hereinafter, a superconducting power transmission heat insulation multiplex pipe laying apparatus 100 using the superconducting power transmission heat insulation multiplex pipe 1 will be described with reference to FIGS. FIG. 5 is a schematic diagram showing an example of a side view of the superconducting power transmission heat insulating multi-pipe laying apparatus 100. As shown in FIG. The rightward arrow in FIG. 5 indicates the direction in which the heat insulating multiple tube 1 is conveyed. That is, the left side of FIG. 5 is the upstream side, and the right side is the downstream side.
A superconducting power transmission heat insulation multiple pipe laying apparatus 100 according to the present embodiment includes a heat insulation multiple pipe 1 into which a superconducting cable core 2 is inserted, and a flattening device 40 for increasing the roundness of the heat insulation multiple pipe 1 . As shown in FIG. 5, a bendback device 50 may be provided upstream of the flattening correction device 40, and a drum 60 around which the heat insulating multiple tube 1 is wound may be provided on the upstream side.
A superconducting power transmission heat insulating multi-pipe laying apparatus 100 according to the present embodiment cools an inner pipe 11 that is a straight pipe, an outer pipe 12 that is a straight pipe and is arranged outside the inner pipe 11, and a superconducting cable core 2. A flow path for the coolant for the cooling, which is a flow path FP2 formed inside the inner tube 11, a heat-resistant radiation layer 13 provided on the outer surface of the inner tube 11, and between the outer tube 12 and the heat-resistant radiation layer 13. and a plurality of heat insulating materials 14 arranged at predetermined intervals D in the axial direction of the inner pipe 11 .

The flatness correction device 40 is in contact with the outer tube 12 . The flatness correction device 40 includes a plurality of rollers 41A, 41B, 41C. The rollers 41A, 41B, 41C are slotted rollers. A substantially circular hole shape formed by the rollers 41A, 41B, and 41C corresponds to the outer diameter of the heat insulating multiple tube 1. As shown in FIG. The rollers 41A, 41B and the roller 41C are arranged so as to sandwich the heat insulating multiple tube 1 therebetween. The heat insulation multiple pipe 1 can be flattened by inserting the heat insulation multiple pipe 1 into the flattening device 40 and conveying and moving it along the longitudinal direction of the heat insulation multiple pipe 1 .

A plurality of rollers 41A, 41B, and 41C may also be used in the drum 60 around which the heat insulating multi-layer pipe 1 is wound and the bend-back device 50 .

Since a straight tube is used as the inner tube 11, the inner surface of the inner tube 11 is smooth, and the pressure loss of the refrigerant in the second flow path FP2 formed inside the inner tube 11 can be reduced. In addition, since the heat insulating material 14 is arranged between the inner tube 11 and the outer tube 12 with a predetermined interval D, the heat insulating material 14 serves as a spacer for transmitting bending stress. flatness can be reduced. Moreover, since both the inner tube 11 and the outer tube 12 are straight tubes, the manufacturing cost can be suppressed as compared with the case of using corrugated tubes.

A predetermined interval D for installing the heat insulating material 14 is more than 50 mm and 180 mm or less. The heat insulating multi-layer tube 1 can be flattened by the flattening device 40 . As a result, flattening of the inner tube 11 can be suppressed more effectively. That is, the roundness of the inner tube 11 can be ensured. In addition, variations in the flatness of the inner tube 11 and the outer tube 12 in the axial direction can be suppressed. As a result, it is possible to suppress variations in the flow path area of the second flow path FP2 in the axial direction, especially for the inner pipe 11, so that the flow velocity of the coolant flowing through the second flow path FP2 is made uniform in the axial direction. The degree of cooling of the superconducting cable core 2 can be made uniform in the axial direction.

The heat insulating material 14 is cylindrical. As a result, the heat insulating material 14 and the inner surface of the outer tube 12 are in surface contact, and local stress concentration on the outer tube 12 can be prevented, so that local deformation of the outer tube 12 can be reliably prevented. In addition, since the outer tube 12 can be supported over the entire circumference by the heat insulating material 14, flattening of the outer tube 12 can be suppressed more effectively.

Further, the heat insulating material 14 is formed with a vent hole or a groove penetrating in the axial direction of the inner tube 11 . As a result, vacuuming between the inner tube 11 and the outer tube 12 can be performed in a short period of time via the vent holes or grooves.

Hereinafter, a construction method 200 for the superconducting power transmission heat insulating multiple pipe 1 and a construction method 300 for the superconducting cable C will be described with reference to FIGS.
As for the construction method 200 for the heat insulating multiple pipe 1, first, the heat insulating multiple pipe 1 is bent and wound around a drum (bending step; S200). The heat-insulating multiple tube 1 wound around the drum is straightly bent back (bending back step; S201).
As for the construction method 300 of the superconducting cable C, first, the superconducting cable C (insulating multiple tube 1 with the superconducting cable core 2 inserted) is bent and wound around a drum (bending step; S300). The superconducting cable C wound around the drum is straightly bent back (bending back step; S301).

Next, the roundness of the heat insulating multi-layer tube 1 or the superconducting cable C bent back in the unbending steps S201 and S301 is increased by the flattening device (flatness straightening steps; S202 and S302). The flatness correction device 40 includes a plurality of rollers 41A, 41B, 41C. The rollers 41A, 41B, 41C are slotted rollers. A substantially circular hole shape formed by the rollers 41A, 41B, and 41C corresponds to the outer diameter of the heat insulating multiple tube 1 or the superconducting cable C. As shown in FIG. The rollers 41A, 41B and the roller 41C are arranged so as to sandwich the heat insulating multiple tube 1 or the superconducting cable C therebetween. The heat insulation multiple pipe 1 or the superconducting cable C is inserted into a flattening device 40 and conveyed along the longitudinal direction of the heat insulation multiple pipe 1 or the superconducting cable C to flatten the heat insulation multiple pipe 1 or the superconducting cable C. be able to.

The heat insulating multiple pipe 1 according to the present embodiment includes an inner pipe 11 that is a straight pipe, an outer pipe 12 that is a straight pipe and is arranged outside the inner pipe 11, and a heat-resistant radiation layer provided on the outer surface of the inner pipe 11. and a plurality of heat insulating materials 14 provided between the outer tube 12 and the heat-resistant radiation layer 13 and arranged at predetermined intervals in the axial direction of the inner tube 11 . Inside the inner tube 11, a coolant flow path FP2 for cooling the superconducting cable core 2 is formed.

Since a straight tube is used as the inner tube 11, the inner surface of the inner tube 11 is smooth, and the pressure loss of the refrigerant in the second flow path FP2 formed inside the inner tube 11 can be reduced. In addition, since the heat insulating material 14 is arranged between the inner tube 11 and the outer tube 12 with a predetermined gap D, the heat insulating multiple tube 1 or the superconducting cable C is subjected to bending steps S200 and S300 and bending back steps S201 and S301. And even if the flattening steps S202 and S302 are performed, the heat insulating material 14 serves as a spacer for transmitting bending stress, and flattening of the inner tube 11 and the outer tube 12 can be suppressed. That is, even when the inner tube 11 and the outer tube 12 are straight tubes, the bending steps S200 and S300, the unbending steps S201 and S301, and the flattening steps S202 and S302 of the heat insulating multiple tube 1 or the superconducting cable C are possible. As a result, a long heat-insulating multiple tube 1 or a superconducting cable C can be manufactured. Moreover, since both the inner tube 11 and the outer tube 12 are straight tubes, the manufacturing cost can be suppressed as compared with the case of using corrugated tubes.

A predetermined interval D for installing the heat insulating material 14 is more than 50 mm and 180 mm or less. Further, in the flattening steps S202 and S302, the heat insulating multiple tube 1 or the superconducting cable C can be flattened by the flattening device 40. FIG. As a result, flattening of the inner tube 11 due to the bending steps S200 and S300 and the unbending steps S201 and S301 of the heat insulating multiple tube 1 or the superconducting cable C can be suppressed more effectively. That is, the roundness of the inner tube 11 can be ensured. In addition, it is possible to suppress variation in the axial direction of the flatness of the inner tube 11 and the outer tube 12 after performing the flattening steps S202 and S302. As a result, it is possible to suppress variations in the flow path area of the second flow path FP2 in the axial direction, particularly for the inner tube 11, so that the flow velocity of the coolant flowing through the second flow path FP2 is made uniform in the axial direction. The degree of cooling of the superconducting cable core 2 can be made uniform in the axial direction.

The heat insulating material 14 is cylindrical. As a result, when the heat insulating multiple tube 1 or the superconducting cable C is subjected to the bending steps S200 and S300, the heat insulating material 14 and the inner surface of the outer tube 12 come into surface contact to prevent local stress concentration on the outer tube 12. Therefore, local deformation of the outer tube 12 can be reliably prevented. In addition, since the outer tube 12 can be supported over the entire circumference by the heat insulating material 14, the outer tube 12 can be flattened by the bending steps S200 and S300 and the bending back steps S201 and S301 of the heat insulating multiple tube 1 or the superconducting cable C. can be suppressed more effectively.

Further, the heat insulating material 14 is formed with a vent hole or a groove penetrating in the axial direction of the inner tube 11 . As a result, vacuuming between the inner tube 11 and the outer tube 12 can be performed in a short period of time via the vent holes or grooves.

(Example)
An example of the result of measuring the roundness of the inner tube 11 of the heat insulating multiplex tube 1 for superconducting power transmission according to this embodiment will be described.
Adiabatic multi-pipe no. Four of 1 to 4 were used. Adiabatic multi-pipe no. 1 to No. 4 are common in the following points (1) to (4).
(1) Inner tube 11: straight tube, outer diameter 60.5 mm, thickness 2.0 mm, length 1800 mm, SUS316
(2) Outer tube 12: straight tube, outer diameter 76.3 mm, thickness 2.0 mm, length 1800 mm, SUS316
(3) Heat insulating material 14: Width (axial length) 40 mm, thickness 3.0 mm, fluorine resin (4) Heat-resistant radiation layer 13: thickness 2.0 mm, length 1800 mm

Adiabatic multi-pipe no. 1 to No. 4, the roundness of the inner tube 11 was measured by changing the predetermined interval D of the heat insulating material 14 . The predetermined intervals D of the heat insulating material 14 were set to 50 mm, 140 mm, 230 mm, and 320 mm. After bending, unbending, and flattening the heat-insulating multiple tube 1, the roundness of the inner tube 11 was measured.

As the bending process, three bending rollers arranged at intervals of 200 mm were used to perform three-point bending of the heat insulating multi-layer tube 1 . As the bending back process, the heat insulating multiple tube 1 after the bending process was bent back so as to return to a straight shape. After that, flatness correction processing was performed using three rollers. The distance between the roller rotation axes of the rollers 41A and 41B in the X direction was arranged at intervals of 400 mm, and the distance between the roller rotation axes of the rollers 41A and 41C in the X direction was arranged at intervals of 200 mm. The size (length) of the heat insulating material 14 in the X direction was set to 40 mm.

Roundness is measured by measuring the length of the portion with the smallest diameter in the cross section perpendicular to the axial direction of the inner pipe 11 after flattening correction processing as the minor diameter (mm), and measuring the length of the portion where the diameter is the largest The length of the bent portion was measured as the major axis (mm), and it was obtained by dividing the minor axis by the major axis. That is, the roundness was determined as "(minor axis/major axis) x 100 (%)".
The larger the roundness value, the closer the cross section of the inner tube 11 after the flattening process is to a perfect circle, indicating that the flattening of the inner tube 11 is suppressed. The roundness was measured for each of the cross section of the inner pipe 11 where the heat insulating material 14 is arranged and the cross section of the portion where the heat insulating material 14 is not arranged.

FIG. 3 shows an example of the measurement result of the roundness of the inner tube 11. As shown in FIG. 3 indicates whether or not the heat insulating material 14 is arranged at the measurement location of the heat insulating multiple pipe 1 . FIG. 3 shows measurement results of the major axis, the minor axis, and the circularity of a cross section in which the heat insulating material 14 is arranged and a cross section in which the heat insulating material 14 is not arranged. "-" in FIG. 3 indicates that no measurement was performed.

In FIG. 4, each adiabatic multi-pipe No. 3 in FIG. 1 to No. 4 were compared for roundness. As shown in FIG. 3, No. 4 showed approximately the same degree of circularity regardless of the presence or absence of the heat insulating material 14. 1, No. 2, the circularity of the section where the heat insulating material 14 is not arranged is 90.7% and 92.5%, respectively. Insulation multiple pipe No. 50 and 140 mm between the insulation materials 14 were used. 1, No. 2, high roundness could be secured.

Here, the larger the roundness, the more the flatness of the inner tube 11 after the flattening process is suppressed, so the roundness is preferably large. In Patent Document 1, it is said that the roundness of both the inner tube and the outer tube is important. We have found that the circularity of the inner tube 11 is more important than the circularity of the inner tube 12 .

From the above, it was found that the preferable range of the predetermined interval D of the heat insulating material 14 is more than 50 mm and 180 mm or less.

Although the embodiments of the present invention have been described above, the above embodiments are presented as examples, and the scope of the present invention is not limited only to the above embodiments. The above embodiment can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. The above-described embodiments and modifications thereof are included in the invention described in the claims and their equivalents, as well as being included in the scope and gist of the invention. For example, vents or grooves formed in the insulation 14 may be omitted. Even in this case, the inner tube 11 and the outer tube 12 can be evacuated through the gap between the heat insulating material 14 and the outer tube 12, for example. Alternatively, the vent hole may be provided only in the radially central portion of the heat insulating material 14 .

1 Thermal insulation multiplex tube for superconducting power transmission (thermal insulation multiplex tube)
2 Superconducting cable core 11 inner tube 12 outer tube 13 heat-resistant radiation layer 14 heat insulating material 15 vacuum heat insulating portion 21 corrugated tube 22 superconducting conductor 23 heat insulating layer 24 superconducting layer 25 electrical insulating layer 26 shield superconducting layer 27 electrical insulating layer 28 conductor protection layer 40 flattening devices 41A, 41B, 41C rollers 100 superconducting power transmission heat insulation multiple pipe laying device 200 superconducting power transmission heat insulation multiple pipe construction method 300 superconducting cable construction method FP1 first flow path FP2 second flow path S200, S300 Bending process S201, S301 Unbending process S202, S302 Flattening process

The present invention has been made in view of the above findings. The gist of the present invention employs the following means.
(1) A superconducting power transmission heat insulation multiplex tube according to an embodiment of the present invention is a superconducting power transmission heat insulation multiplex tube into which a superconducting cable core is inserted,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
the predetermined interval is more than 50 mm and 180 mm or less;
The predetermined interval is an interval corresponding to a flattening device for increasing the roundness of the heat insulating multiple tube for superconducting power transmission.
( 2 ) In (1) above,
The flatness correction device includes a plurality of rollers,
The predetermined interval may correspond to the interval between the plurality of rollers.
( 3 ) In ( 2 ) above,
The predetermined interval may be set such that the plurality of rollers and the two heat insulators overlap each other when viewed along the first direction.
( 4 ) In ( 2 ) above,
The intervals between the plurality of rollers may be set such that the plurality of rollers and the two heat insulators overlap each other when viewed along the first direction.
( 5 ) A superconducting power transmission thermal insulation multi-pipe laying apparatus according to an embodiment of the present invention,
1. A superconducting power transmission insulation multiplex pipe laying device including a superconducting power transmission insulation multiplex pipe into which a superconducting cable core is inserted and a flattening device for increasing the roundness of the superconducting power transmission insulation multiplex pipe,
The heat insulating multiple tube for superconducting power transmission,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
The flattening correction device is in contact with the outer tube.
( 6 ) A method for constructing a superconducting power transmission thermal insulation multiplex pipe according to an embodiment of the present invention includes:
The construction method for the superconducting power transmission heat insulating multiple pipe according to any one of ( 1 ) to ( 4 ) above,
a bending step of bending the superconducting power transmission heat insulating multiple tube;
a bending-back step of bending back the heat-insulating multiple pipe for superconducting power transmission bent in the bending step;
A flattening step of increasing the roundness of the superconducting power transmission heat insulating multi-pipe bent back in the flattening step by the flattening device;
Prepare.
( 7 ) A superconducting cable construction method according to an embodiment of the present invention includes:
A method for constructing a superconducting cable comprising: a superconducting power transmission thermal insulation multiplex tube according to any one of the above ( 1 ) to ( 4 ); and a superconducting cable core to be inserted into the superconducting power transmission thermal insulation multiplex tube. ,
a bending step of bending the superconducting cable;
a bending-back step of bending back the superconducting cable bent in the bending step;
A flattening correction step of increasing the roundness of the superconducting cable bent back in the unbending step by the flattening correction device;
Prepare.

Claims (9)

A superconducting power transmission heat insulation multiplex tube into which a superconducting cable core is inserted,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
The predetermined interval is more than 50 mm and 180 mm or less,
A heat insulating multiple tube for superconducting power transmission, characterized by: The predetermined interval is more than 50 mm and 140 mm or less,
The heat insulating multiple tube for superconducting power transmission according to claim 1, characterized in that: The predetermined interval is an interval corresponding to a flattening correction device that increases the roundness of the heat insulating multiple tube for superconducting power transmission.
3. The heat-insulating multiple tube for superconducting power transmission according to claim 1 or 2, characterized in that: The flatness correction device includes a plurality of rollers,
The predetermined interval and the interval between the plurality of rollers correspond to
The heat insulating multiple tube for superconducting power transmission according to claim 3, characterized in that: The predetermined interval is set so that the plurality of rollers and the two heat insulating materials overlap when viewed along the first direction,
5. The heat insulating multiple tube for superconducting power transmission according to claim 4, characterized in that: The intervals between the plurality of rollers are set so that the plurality of rollers and the two heat insulating materials overlap when viewed along the first direction.
5. The heat insulating multiple tube for superconducting power transmission according to claim 4, characterized in that: 1. A superconducting power transmission insulation multiplex pipe laying device including a superconducting power transmission insulation multiplex pipe into which a superconducting cable core is inserted and a flattening device for increasing the roundness of the superconducting power transmission insulation multiplex pipe,
The heat insulating multiple tube for superconducting power transmission,
an inner tube that is a straight tube;
an outer tube that is a straight tube and is arranged outside the inner tube;
a coolant channel for cooling the superconducting cable core, the channel being formed inside the inner tube;
a heat-resistant radiation layer provided on the outer surface of the inner tube;
a plurality of heat insulating materials provided between the outer tube and the heat-resistant radiation layer and arranged at predetermined intervals in the axial direction of the inner tube;
with
The flat correction device is in contact with the outer tube,
A heat insulating multiple pipe laying device for superconducting power transmission, characterized by: A method for constructing a superconducting heat-insulating multiple pipe for power transmission according to any one of claims 2 to 6,
a bending step of bending the superconducting power transmission heat insulating multiple tube;
a bending-back step of bending back the heat-insulating multiple pipe for superconducting power transmission bent in the bending step;
A flattening step of increasing the roundness of the superconducting power transmission heat insulating multi-layer tube that has been bent back in the flattening step by the flattening device;
A method for constructing a heat insulating multiple pipe for superconducting power transmission, comprising: A superconducting cable construction method comprising the superconducting power transmission thermal insulation multiplex tube according to any one of claims 2 to 6 and a superconducting cable core to be inserted into the superconducting power transmission thermal insulation multiplex tube,
a bending step of bending the superconducting cable;
a bending-back step of bending back the superconducting cable bent in the bending step;
A flattening correction step of increasing the roundness of the superconducting cable bent back in the unbending step by the flattening correction device;
A method for constructing a superconducting cable, comprising:

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