JP5305180B2 - Room-temperature insulated superconducting cable and manufacturing method thereof - Google Patents

Description

  The present invention relates to a room temperature insulation type superconducting cable comprising a low temperature conductive part in which a conductor part is housed in a heat insulating tube, and a room temperature coated part having a room temperature side electric insulation layer surrounding the outer periphery of the low temperature conductive part, and its manufacture It is about the method.

  In general, a superconducting cable has a configuration in which a conductor portion having a superconducting conductor layer on the outer periphery of a former is housed in a heat insulating tube made of a double metal tube. In such a superconducting cable, there are the following two configurations for electrically insulating the superconducting cable from the outside. The first configuration is a low-temperature insulation type configuration in which a conductor portion provided with an electric insulation layer on a superconducting conductor layer is accommodated in the heat insulating tube, and the electric insulation layer provided in the conductor portion is also cooled by a refrigerant. . In the second configuration, a low-temperature conductive portion including a former and a superconducting conductor layer is accommodated in the heat insulating tube, and an electric insulating layer is formed on the heat insulating tube, and the electric insulating layer is not cooled by the refrigerant. It is a room temperature insulation type structure (see, for example, Non-Patent Document 1). In particular, the latter room-temperature insulated superconducting cable has an advantage that the insulation material and structure of an existing normal conducting cable can be applied.

"Experimental 35kV / 121MVA Superconducting Cable System Installed at Pujy Substituting in Southern China Power Grid 1 Transactions on Electric 13"

  However, the room-temperature insulated superconducting cable described above has room for improvement in terms of productivity.

  In general, the room-temperature insulated superconducting cable is manufactured sequentially from the center side. In that case, if there is a defect in either the low temperature conductive part or the normal temperature coated part at the stage when the room temperature insulated superconducting cable is completed, the entire superconducting cable must be remade. Moreover, in the process of forming the room temperature coating part on the outer periphery of the low temperature conductive part, there is a possibility of damaging the electric insulation layer of the room temperature coating part and the heat insulation tube of the low temperature conductive part. Must be remade. Thus, the productivity of the room temperature insulated superconducting cable is not good.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a room temperature insulated superconducting cable that is more productive than the conventional one and a method for manufacturing the same.

The manufacturing method of the room temperature insulated superconducting cable according to the present invention includes the following steps.
(Process A) formed on the outer periphery of the conductor part formed by forming a superconducting conductor layer on the outer periphery of the former, the heat insulating pipe that accommodates the conductor part inside and maintaining the conductor part at a cryogenic temperature, and the heat insulating pipe A low-temperature conductive portion having a coating layer.
(Step B) A room-temperature coated portion having a pipe-like structure having an inner diameter larger than the outer diameter of the low-temperature conductive portion and a room-temperature side electric insulating layer formed on the outer periphery of the pipe-like structure is produced.
(Step C) The low-temperature conductive part produced in Step A is inserted into the room temperature coating part produced in Step B.

  As in the method for producing a room temperature insulated superconducting cable of the present invention, a low temperature conductive part and a room temperature coated part are individually manufactured, and then a low temperature conductive part is inserted into the room temperature coated part to produce a superconducting cable. The yield of superconducting cables can be improved. This is because the superconducting cable can be manufactured by inspecting the low-temperature conductive portion and the normal-temperature coating portion, respectively, and combining the low-temperature conductive portion and the normal-temperature coating portion without any defects. On the other hand, unlike the manufacturing method of the present invention, when the superconducting cable is manufactured sequentially from the center side of the superconducting cable, there is a problem in either the low temperature conductive part or the room temperature covering part at the stage where the superconducting cable is completed. If so, the entire superconducting cable must be re-created, and in the process of forming the room temperature coating on the outer periphery of the low temperature conductive part, the room temperature side electrical insulation layer of the room temperature coating part and the insulation tube of the low temperature conductive part are damaged. There is also a possibility of end.

  Further, in the method for manufacturing a room temperature insulated superconducting cable according to the present invention, a pipe-like structure is formed on the innermost periphery of the cylindrical room temperature coated portion, and on the outermost periphery of the low temperature conductive portion inserted into the room temperature coated portion. A coating layer is formed. Therefore, when a low temperature conductive part is inserted into the inside of the room temperature covering part, it is possible to effectively prevent damage to the configuration essential for the operation of the room temperature insulated superconducting cable. This essential structure is a room temperature side electric insulation layer in the room temperature coating part, and a heat insulating tube that maintains the superconducting conductor at an extremely low temperature in the low temperature conductive part.

  Further, the room temperature insulation type superconducting cable of the present invention has a conductor part formed by forming a superconducting conductor layer on the outer periphery of the former, and a low-temperature tube having a heat insulating tube for accommodating the conductor part therein and maintaining the conductor part at a very low temperature. A conductive portion and a normal temperature covering portion having a normal temperature side electric insulating layer surrounding the outer periphery of the heat insulating tube. In the room temperature insulation type superconducting cable of the present invention, the room temperature coating portion has a pipe-like structure that supports the room temperature side electric insulation layer from the inner peripheral side, and the low temperature conductive portion is a coating layer formed on the outer periphery of the heat insulating tube. It is characterized by having.

  According to the above-described room temperature insulated superconducting cable of the present invention, the low temperature conductive part and the room temperature coating part can be handled separately. As a result, when the low-temperature conductive part of the cable is damaged along with the use of the room-temperature insulated superconducting cable after installation, only the low-temperature conductive part can be replaced. In particular, since the coating layer is formed on the outermost periphery of the low-temperature conductive portion, when replacing the low-temperature conductive portion, the low-temperature conductive portion can be easily pulled out from the normal temperature coating portion. In addition, by providing a pipe-like structure on the room temperature coating part and a coating layer on the low temperature conductive part, when inserting the low temperature conductive part inside the room temperature coating part, the low temperature conductive part is inserted from the inside of the room temperature coating part. Even when it is pulled out, it is possible to effectively prevent damage to the components essential to the operation of the room temperature insulated superconducting cable, such as the room temperature side electrical insulation layer of the room temperature coated part and the heat insulating tube of the low temperature conductive part.

  Hereinafter, preferred embodiments of the room temperature insulated superconducting cable of the present invention will be described in detail.

  As one form of the room temperature insulation type superconducting cable of the present invention, the room temperature coating part is disposed inside the room temperature side electric insulation layer and outside the heat insulating tube, and normally shares an excessive abnormal current typified by a short circuit current. It is preferable to provide a conductive shunt conductor.

  By providing the shunt conductor for sharing the abnormal current in the normal temperature coating portion, the abnormal current amount flowing in the low temperature conductive portion when the abnormal current is generated can be reduced. As a result, it is possible to suppress an increase in the refrigerant temperature in the low temperature conductive part, and it is possible to suppress deterioration of the superconducting conductor layer due to an excessive current. In particular, by suppressing the rise in the refrigerant temperature, it becomes easy to restore the refrigerant temperature to a temperature suitable for superconducting power transmission, and the liquid refrigerant is gasified by the rise in the refrigerant temperature when the refrigerant is a liquid refrigerant. Can be suppressed.

  The shunt conductor is preferably made of copper. Since the electrical resistance value of copper is low among various metals and alloys, it is suitable as a shunt conductor. When an abnormal current is generated, the abnormal current is diverted to the superconducting conductor layer, the former, and the shunt conductor. However, it is desirable to reduce the current flowing through the former and increase the current flowing through the shunt conductor. For this purpose, it is effective to reduce the resistance value of the shunt conductor, which is a normal conducting conductor, and copper is preferable for reducing the resistance value. When the current flowing through the shunt conductor is increased, the cross-sectional area of the former can be reduced correspondingly, and as a result, the size of the superconducting cable can be reduced.

  As one form of the room temperature insulation type superconducting cable of the present invention, the coefficient of static friction of the surface of the coating layer with respect to the pipe-like structure is preferably 0.3 or less.

  The coefficient of static friction on the surface of the coating layer is related to the ease of inserting the low temperature conductive part into the room temperature coating part and the ease of drawing out the low temperature conductive part from the room temperature coating part. The smaller the coefficient of static friction of the coating layer, the easier it is to insert and remove the low temperature conductive part from the room temperature coating part, and when the room temperature coating part and the low temperature conductive part come into contact with each other, they are both rubbed strongly to prevent damage. You can also The coefficient of static friction is more preferably 0.2 or less, and most preferably 0.1 or less. In addition, a static friction coefficient can be calculated | required by the static friction coefficient measurement based on JISK7125.

  As one form of the room temperature insulation type superconducting cable of the present invention, the outer peripheral contour line of the longitudinal section of the coating layer may be formed in an uneven shape so that the contact area with the pipe-like structure on the surface of the coating layer is reduced. .

  The ease of inserting / removing the low temperature conductive portion with respect to the normal temperature coating portion varies depending on not only the material of the coating layer but also the surface shape of the coating layer. When the outer peripheral contour line of the longitudinal section of the coating layer is formed in an uneven shape as in the above configuration, the contact area with the pipe-like structure on the surface of the coating layer is reduced, and the low temperature conductive part is inserted into and removed from the room temperature coating part. It becomes easy. For example, the outer peripheral contour line may be a sine wave shape or a sawtooth wave shape. In particular, in the case of the latter configuration, it becomes easy to insert and remove the low temperature conductive portion with respect to the room temperature coating portion in one of the longitudinal directions of the low temperature conductive portion. On the other hand, since the low-temperature conductive part is difficult to move with respect to the room-temperature coated part on the other side in the longitudinal direction of the low-temperature conductive part, in the installed room-temperature insulated superconducting cable, the low-temperature conductive part in the room-temperature coated part is moved. Can be suppressed.

  According to the method for producing a room temperature insulation type superconducting cable of the present invention, a room temperature insulation type superconducting cable can be produced with good yield. Further, according to the room temperature insulated superconducting cable of the present invention, even if the low temperature conductive part of the superconducting cable is damaged due to the operation of the superconducting cable, the superconducting cable can be operated only by replacing the damaged low temperature conductive part. You can resume.

(A) is a schematic cross-sectional view of the room-temperature insulated superconducting cable described in Embodiment 1, and (B) is a cross-sectional view showing a state before the assembly. It is a longitudinal cross-sectional view of the heat insulation pipe | tube with a coating used for a normal temperature insulation type superconducting cable. It is a longitudinal cross-sectional view of the heat insulation pipe | tube with a coating used for a normal temperature insulated superconducting cable, Comprising: It is a figure which shows the coating layer which has a surface shape different from FIG.

  Hereinafter, an embodiment of the room temperature insulated superconducting cable of the present invention will be described based on the drawings. In the figure, the same reference numeral indicates the same name object.

<Embodiment 1>
≪Overall structure≫
A room-temperature insulated superconducting cable 100 shown in FIG. 1A is formed by combining a separately manufactured low-temperature conductive part 1 and a pipe-shaped normal-temperature covering part 2 that accommodates the low-temperature conductive part 1 therein. It is characterized by being. In this room temperature insulated superconducting cable 100, a coating layer 16 is provided on the outermost periphery of the low temperature conductive part 1 in order to facilitate the insertion / extraction of the low temperature conductive part 1 with respect to the normal temperature covered part 2. A pipe-like structure 21 is provided on the inner periphery. Hereinafter, each configuration will be sequentially described in detail.

≪Low temperature conductive part≫
The low temperature conductive part 1 is a long body in which the conductor part 10 is accommodated inside the heat insulating tube 13.

[Conductor]
The conductor 10 typically includes a former 11, a superconducting conductor layer 12, and a protective layer (not shown) in order from the center. The former 11 is a member used as a support for the superconducting conductor layer 12. For example, a pipe-shaped hollow body as shown in FIG. 1 can be used as the former 11. The hollow former 11 can use the inside as a flow path of the refrigerant 131. As the shape of the former 11, a solid body can be used in addition to the hollow body. On the other hand, the material of the former 11 is not particularly limited. If the former 11 is simply used as a support for the superconducting conductor layer 12, the former 11 may be made of a non-conductive material such as a resin, or the former 11 may be used as a flow path for abnormal current (short-circuit current). As long as this function is also provided, it may be made of a normal conductive metal material such as copper or aluminum. However, if the former 11 is made of a non-conductive material, it is preferable to form the shunt conductor 22 in the room temperature coating 2 described later. Taking the above points into consideration, a specific configuration of the former 11 is exemplified. For example, the hollow body former 11 may be a pipe made of a metal material, and the solid former 11 may be enamel, for example. The thing which twisted together the some metal wire provided with this insulation coating can be mentioned.

  Next, as the superconducting conductor layer 12, for example, a tape-like wire material including an oxide superconductor can be suitably used. Examples of the tape-shaped wire include Bi2223 superconducting tape wire (sheath wire in which a filament made of an oxide superconductor is arranged in a stabilizing metal such as Ag-Mn and Ag), RE123 thin film wire (RE: rare earth element, For example, Y, Ho, Nd, Sm, Gd, etc. (Laminated wire material in which an oxide superconducting phase is formed on a metal substrate). The superconducting conductor layer 12 includes a single layer structure or a multilayer structure formed by spirally winding the tape-shaped wire.

  The protective layer (not shown) is for protecting the superconducting conductor layer 12 and ensuring insulation from the heat insulating tube 13, and can be formed by winding kraft paper or the like.

[Insulated pipe]
The heat insulating tube 13 that houses the conductor portion 10 includes an inner tube 14 that houses the conductor portion 10 therein, and an outer tube 15 that houses the inner tube 14 inside. The inner tube 14 is filled with a refrigerant 131 (typically liquid nitrogen, liquid helium, helium gas, etc.) for maintaining the superconducting conductor layer 12 in a superconducting state, and functions as a refrigerant flow path. By forming the heat insulating tube 13 with the inner tube 14 and the outer tube 15 provided on the outer periphery of the inner tube 14, it is possible to suppress the temperature of the refrigerant 131 from rising due to heat entering from the outside. A vacuum is drawn between the inner tube 14 and the outer tube 15 to form a vacuum heat insulating layer. In addition, if a heat insulating material such as super insulation or a spacer that separates the inner tube 14 and the outer tube 14 is disposed between the inner tube 14 and the outer tube 15, the heat insulating property of the heat insulating tube 13 can be improved. In addition, in this embodiment, although the heat insulation pipe | tube of a double pipe structure is utilized as a heat insulation pipe | tube, you may utilize the heat insulation pipe | tube more than a triple pipe.

  Examples of the constituent material of the inner tube 14 and the outer tube 15 include metals such as stainless steel, aluminum, and alloys thereof. Since the metal is excellent in corrosion resistance, it is suitable as a constituent material of the heat insulating tube 13 for holding and transporting various fluids. The materials of both pipes 14 and 15 may be different. Both pipes 14 and 15 should be corrugated pipes that have been corrugated over their entire length, or straight pipes made of a relatively soft and flexible material such as aluminum or its alloys. Can be bent. By adopting the heat insulating tube 13 having flexibility in this way, the superconducting cable 100 can be easily bent at the time of transportation or laying. Furthermore, by forming the heat insulating tube 13 with a corrugated tube, the heat stress can be relieved by deformation when the heat insulating tube 13 is cooled by the refrigerant 131 and thermally contracts.

[Coating layer]
The heat insulating tube 13 of this embodiment further includes a coating layer 16 formed on the outer periphery of the outer tube 15. The coating layer 16 has a function of preventing the heat insulating tube 13 from being damaged when the low temperature conductive part 1 is inserted into the room temperature covering part 2 later, as shown in a method for manufacturing the room temperature insulated superconducting cable 100 described later. Have. The coating layer 16 also has a function of easily inserting the low temperature conductive portion 1 into the room temperature coating portion 2 and facilitating extraction of the low temperature conductive portion 1 housed in the room temperature coating portion 2. As a characteristic required for the coating layer 16 to achieve both of these functions, the coefficient of static friction of the surface of the coating layer 16 with respect to the pipe-like structure 21 that rubs against the coating layer 16 is 0.3 or less, preferably 0.2. Hereinafter, it is most preferably 0.1 or less. If the coefficient of static friction on the surface of the coating layer 16 is small, the low temperature conductive part 1 can be easily inserted into and removed from the room temperature coating part 2, and the inner peripheral surface of the room temperature coating part 2 (a pipe-like structure 21 to be described later) during the insertion and removal. It is possible to prevent the outer peripheral surface of the low-temperature conductive portion 1 from rubbing strongly against the inner peripheral surface).

  Here, the static friction coefficient of the surface of the coating layer 16 can be obtained as follows. First, a flat test piece is prepared from the constituent material of the coating layer 16, and a flat test piece is also prepared from the constituent material of the pipe-like structure 21. And using these test pieces, the static friction coefficient measurement based on JIS K7125 is performed.

  The factor that determines the static friction coefficient of the surface of the coating layer 16 is the material constituting the coating layer 16. Examples of the constituent material of the coating layer 16 include resin materials such as epoxy, polyvinyl chloride, and polyethylene. These resin materials have moderate elasticity, and can reduce damage to the coating layer 16 itself, and can also reduce damage to a pipe-like structure 21 (described later) that rubs against the coating layer 16. Moreover, according to these resin materials, it can form easily in the outer periphery of the heat insulation pipe | tube 13 by extrusion etc. The coating layer 16 may be formed by winding a tape-shaped resin material around the outer periphery of the heat insulating tube 13.

  In addition to the material of the coating layer 16, the shape of the coating layer 16 can be cited as a factor that determines the ease with which the low temperature conductive portion 1 can be inserted into and removed from the room temperature coating portion 2. Specifically, if the contact area between the coating layer 16 and the inner circumferential surface of the room temperature coating portion 2 (the inner circumferential surface of the pipe-like structure 21 described later) is small, the low temperature conductive portion 1 is inserted into and removed from the room temperature coating portion 2. It becomes easy to do. Therefore, it is preferable to form an uneven shape on the surface of the coating layer 16. Specific examples of the surface shape of the coating layer 16 will be described with reference to FIGS. 2 and 3, which are longitudinal sectional views of a room temperature insulated superconducting cable. 2 and 3, only the outer tube 15 and the coating layer 16 are shown.

  First, the coating layer 16 shown in FIG. 2 is formed along the outer peripheral surface shape of the corrugated outer tube 15. The outer peripheral contour line of the coating layer 16 shown in FIG. 2 has a sine wave shape, and the thickness of the coating layer 16 is increased in the concave and convex valley portions of the outer tube 15. Such a shape can be formed by extruding a resin material on the outer periphery of the heat insulating tube 13 or spraying a molten resin material on the outer periphery of the heat insulating tube 13. In order to change the thickness of the coating layer 16 in the longitudinal direction of the outer tube 15 by extrusion, the supply amount of the resin material may be changed at any time during the extrusion process. Further, unlike FIG. 2, the coating layer may be formed thick in the crest portion of the outer tube and thin in the trough portion. By thickening the crest portion, it is possible to effectively protect the portion that actually rubs against the inner peripheral surface of the room temperature coating portion. From this point of view, the coating layer may be formed only on the crest portion of the outer tube. In addition, the coating layer may have a substantially uniform thickness along the shape of the outer tube.

  On the other hand, the outer peripheral outline of the coating layer 16 illustrated in FIG. 3 is formed in a sawtooth wave shape. Examples of the sawtooth wave shape include a substantially isosceles triangle shape in which two sides sandwiching the apex of the mountain portion are substantially equal, and a substantially triangular shape in which one side sandwiching the vertex is longer than the other side. . According to the coating layer 16 having the sawtooth-like outer peripheral contour line, compared to the configuration of FIG. 2, only the direction in which the long sides of the sawtooth are arranged (rightward in the drawing) is applied to the room temperature coating portion 2. The movement resistance of the low temperature conductive part 1 can be reduced. On the other hand, in the direction in which the short sides of the sawtooth wave are arranged (the left direction in the drawing), the low-temperature conductive part 1 is difficult to move with respect to the normal-temperature covering part 2, so in the installed room-temperature insulated superconducting cable 100, The movement of the low temperature conductive part 1 in the room temperature covering part 2 can be suppressed.

  The coating layer 16 may be composed of a plurality of layers made of different materials. In that case, for example, in the layer formed immediately above the heat insulating tube 13, the material may be selected by giving priority to the adhesion and strength with the heat insulating tube 13. On the other hand, a material having a small coefficient of static friction is preferably used for the layer formed on the outermost periphery.

≪Normal temperature coating part≫
The room temperature covering portion 2 includes a pipe-like structure 21 and a room temperature side electrical insulating layer 23 formed on the outer periphery thereof. Here, it is preferable that the room temperature covering portion 2 further includes a shunt conductor 22 serving as a flow path for the abnormal current between the pipe-like structure 21 and the room temperature side electrical insulating layer 23. In this embodiment, the room temperature coating | coated part 2 provided with the shunt conductor 22 is demonstrated.

[Pipe-like structure]
The pipe-like structure 21 is a member that retains and protects the shunt conductor 22 and the room-temperature-side electrical insulation layer 23 formed on the outer peripheral surface thereof. The most important characteristic of the pipe-like structure 21 is strength. In order to give the superconducting cable 100 a predetermined flexibility, the pipe-like structure 21 is also required to have a predetermined flexibility. In consideration of these points, as the pipe-like structure 21, an aluminum straight pipe, a SUS corrugated pipe, or the like can be used. In addition, the pipe-like structure 21 may be made of a non-conductive material such as resin. In addition, if this pipe-like structure 21 is a conductive material, it can share a part of the function of the shunt conductor 22 itself.

  Here, when the surface of the coating layer 16 has an uneven shape, if the pipe-like structure 21 is a corrugated pipe, the unevenness of the coating layer 16 and the unevenness of the inner peripheral surface of the pipe-like structure 21 are caught. There is a fear. Therefore, it is preferable that either the coating layer 16 or the pipe-like structure 21 has a shape without unevenness. In particular, a combination in which the coating layer 16 is provided with irregularities and the pipe-like structure 21 is a straight pipe is preferable. As will be described later, when the shunt conductor 22 and the room temperature side electrical insulating layer 23 are formed on the outer peripheral side of the pipe-like structure 21, a gap is easily formed in the pipe-like structure 21 having irregularities, and the gap is formed. This is because the gap may become an electrical weak point.

[Branch conductor]
The shunt conductor 22 is a normal conducting conductor that shares an abnormal current when an abnormal current (short-circuit current) is generated. The shunt conductor 22 is connected to the superconducting conductor layer 12 and the former 11 at somewhere in the longitudinal direction of the superconducting cable line (typically, an intermediate connection portion or a termination connection portion of the superconducting cable 100). An abnormal current can be shared with the metal component of the superconducting conductor layer 12 and the former 11.

  The shunt conductor 22 is composed of a metal material having a higher conductivity than that of the pipe-like structure 21, that is, a metal material such as copper, aluminum, or silver having a lower electric resistance value, from the viewpoint of sharing the current during an abnormality. . In particular, copper is suitable as the shunt conductor 22 in that it has the second highest conductivity after silver and is much cheaper than silver.

  The said shunt conductor 22 can be formed by winding the member according to the conductor of the existing normal conducting cable, such as a segment conductor comprised with a copper strand wire, on the pipe-shaped structure 21. As shown in FIG.

  The formation thickness of the shunt conductor 22 may be appropriately selected depending on how much abnormal current can be generated in the operation of the superconducting cable line and how much the abnormal current generated is borne by the shunt conductor 22. good. For example, when the former 11 of the low-temperature conductive portion 1 described above is made of a non-conductive material, the thickness of the shunt conductor 22 is determined so that most of the abnormal current can flow through the shunt conductor 22, and the shunt conductor 22 and the superconductor The superconducting conductor layer 12 is protected by sharing an abnormal current with the metal component of the conductor layer 12. Further, if the former 11 is made of a conductive material and the abnormal current is shared not only by the metal components of the shunt conductor 22 and the superconducting conductor layer 12 but also by the former 11, it is shared by the shunt conductor 22. What is necessary is just to determine the thickness of the shunt conductor 22 so that the electric current at the time of abnormality may flow.

[Room-temperature electrical insulation layer]
The room temperature side electrical insulation layer 23 is a layer that electrically insulates the superconducting cable 100 from the external environment. The room-temperature side electrical insulation layer 23 can be made of a material having an excellent electrical insulation strength that has been proven in ordinary conductive cables, typically, crosslinked polyethylene (XLPE) used for CV cables. If the insulating resin such as cross-linked polyethylene is used, the room-temperature-side electrical insulating layer 23 can be easily formed simply by extruding the insulating resin on the outer periphery of the tubular member in which the shunt conductor 22 is formed on the pipe-like structure 21. In addition, the room temperature side electrical insulation layer 23 can employ the same configuration as the insulation layer in the OF cable. For example, the room temperature side electrical insulation layer 23 can be formed by winding tape-like kraft paper or semi-synthetic paper around the outer periphery of the shunt conductor 22 in multiple layers and impregnating the insulation layer with insulation oil such as synthetic oil. .

[Other configurations]
An outer conductor layer (not shown) made of a normal conducting material such as copper or aluminum is typically provided on the outer periphery of the room temperature side electrical insulating layer 23. The outer conductor layer is typically used for electromagnetic shielding. The room-temperature insulated superconducting cable 100 is excellent in manufacturability of the superconducting cable because the normal conducting material can be used for the outer conductor layer as described above. Further, an anticorrosion layer (not shown) for protecting the outer conductor layer is provided on the outer periphery of the outer conductor layer.

≪Effect of room temperature insulated superconducting cable≫
With the configuration of the room temperature insulated superconducting cable 100 according to the embodiment, when the low temperature conductive part 1 is damaged during the operation of the superconducting cable 100, the operation of the superconducting cable 100 can be resumed simply by replacing the damaged low temperature conductive part 1. can do. Further, at the time of this replacement, the coating layer 16 formed on the low temperature conductive portion 1 and the pipe-like structure 21 of the normal temperature coating portion 2 exist, so that the normal temperature electrical insulating layer 23 and the low temperature conductive portion of the normal temperature coating portion 2 are present. The components essential for the operation of the room temperature insulated superconducting cable 100 such as the one heat insulating tube 13 are not damaged.

  Further, in the room temperature insulated superconducting cable 100 of the present embodiment, since the shunt conductor 22 is formed in the room temperature covering portion 2, when an abnormal current occurs, the abnormal current is shared by the shunt conductor 22. be able to. Therefore, it can be avoided that the superconducting conductor layer 12 is quenched and the superconducting conductor layer 12 is deteriorated. Further, since the shunt conductor 22 is provided in the room temperature covering portion 2, the refrigerant 131 of the low temperature conductive portion 1 is not heated by Joule heat generated in the shunt conductor 22. Therefore, the refrigerant 131 can be prevented from being heated and gasified, and the time for cooling the refrigerant 131 to an operable temperature can be shortened. Can be returned to normal operation.

≪Method of manufacturing room temperature insulated superconducting cable≫
The superconducting cable 100 described above can be manufactured by the following steps A to C as shown in FIG. In addition, the order of the process A and the process B is interchangeable.

[Step A]
In step A, the low temperature conductive portion 1 is produced. The low temperature conductive part 1 can be produced by producing the conductor part 10 and sequentially forming the inner tube 14, the outer pipe 15 and the coating layer 16 on the outer periphery of the conductor part 10. In addition, the low-temperature conductive portion 1 may be manufactured by separately manufacturing the conductor portion 10 and the heat insulating tube 13 and inserting the conductor portion 10 into the inner tube 14 of the heat insulating tube 13.

[Step B]
In step B, a room temperature coating portion 2 is produced separately from the low temperature conductive portion 1. First, a pipe-like structure 21 is prepared, and a segment conductor composed of, for example, a copper stranded wire is wound around the outer periphery thereof to form a shunt conductor 22. Next, an insulating resin is coated on the outer periphery of the shunt conductor 22 by, for example, extrusion to form the room temperature side electric insulation layer 23. The room temperature side electrical insulation layer 23 may be formed by winding kraft paper or PPLP (registered trademark of Sumitomo Electric Industries).

  Here, the length of the low temperature conductive portion 1 and the length of the room temperature coating portion 2 do not have to be the same. For example, the low temperature conductive part 1 may be longer than the room temperature coating part 2. In that case, since both ends of the low temperature conductive part 1 are exposed from the room temperature covering part 2, when connecting a plurality of superconducting cables 100 to construct a superconducting cable line, adjacent low temperature conductive parts 1 can be easily connected. .

[Step C]
The low temperature conductive part 1 produced in the process A is inserted into the room temperature coating part 2 produced in the process B. When the low temperature conductive part 1 is inserted into the room temperature coating part 2, the low temperature conductive part 1 may be drawn into the room temperature coating part 2 by pulling the former 11 and the heat insulating tube 13 of the low temperature conductive part 1. Here, a tension member may be provided in the low temperature conductive part 1 in the step A, and the tension member may be assigned the pulling tension when the low temperature conductive part 1 is drawn into the room temperature coating part 2. This tension member can prevent the low temperature conductive portion 1 from being damaged.

  According to the manufacturing method of the room temperature insulated superconducting cable 100 described above, the room temperature insulated superconducting cable 100 of the present invention can be manufactured with a high yield. It is possible to inspect the low-temperature conductive part 1 and the normal-temperature coating part 2 before completing the normal-temperature insulated superconducting cable 100 in Step C. This is because the insulated superconducting cable 100 can be completed.

  Further, since the coating layer 16 formed on the low temperature conductive part 1 and the pipe-like structure 21 of the room temperature coating part 2 exist, when the low temperature conductive part 1 is inserted into the room temperature coating part 2, the room temperature coating is performed. The components essential to the operation of the room-temperature insulated superconducting cable 100 such as the room-temperature electrical insulation layer 23 of the section 2 and the heat insulating tube 13 of the low-temperature conductive section 1 are not damaged. In particular, by reducing the static friction coefficient of the coating layer 16, the low temperature conductive part 1 can be easily inserted into and extracted from the room temperature coating part 2, and the outer periphery of the low temperature conductive part 1 is formed on the inner peripheral surface of the room temperature coating part 2. It is possible to effectively prevent the surfaces from rubbing strongly and damaging each other.

<Modified Embodiment>
In the embodiment described above, the coating layer 16 formed on the outer periphery of the corrugated heat insulating tube 13 has a corrugated shape. However, the coating layer 16 is formed so as to fill the valley portion of the corrugated heat insulating tube 13, and the coating is performed. The outer peripheral surface of the layer 16 may be a smooth cylindrical surface. In other words, the outer peripheral surface of the heat insulating tube 13 is completely covered with the coating layer 16 so that the corrugated heat insulating tube 13 covering the coating layer 16 looks like a straight pipe. By forming the coating layer 16 in this way, there is an advantage that the heat insulating tube 13 can be prevented from being deformed (elongated) in the longitudinal direction when the corrugated heat insulating tube 13 is retracted.

  The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, although the description is omitted in the embodiment, it is general to form an internal semiconductive layer and an external semiconductive layer on each of the inner peripheral portion and the outer peripheral portion of the room temperature side electric insulating layer 23.

  The room temperature insulated superconducting cable of the present invention can be suitably used for forming a large current transmission network. Moreover, the manufacturing method of the room temperature insulation type superconducting cable of the present invention can be suitably used for the production of the room temperature insulation type superconducting cable of the present invention.

DESCRIPTION OF SYMBOLS 100 Room temperature insulation type superconducting cable 1 Low temperature conductive part 10 Conductor part 11 Former 12 Superconducting conductor layer 13 Heat insulation pipe 14 Inner pipe 15 Outer pipe 131 Refrigerant 16 Coating layer 2 Room temperature coating part 21 Pipe-shaped structure 22 Shunt conductor 23 Room temperature side electric insulation layer

Claims (6)

A conductor part formed by forming a superconducting conductor layer on the outer periphery of the former, and a low-temperature conductive part having a heat insulating tube for storing the conductor part therein and maintaining the conductor part at a cryogenic temperature;
A room temperature coating portion having a room temperature side electric insulation layer surrounding the outer periphery of the heat insulating tube;
A room temperature insulated superconducting cable comprising:
The room temperature coating portion has a pipe-like structure that supports the room temperature side electrical insulating layer from the inner peripheral side,
It said cold conductive section may have a coating layer formed on the outer periphery of the heat-insulated pipe,
The low-temperature conductive part and the room temperature coating part are separately manufactured, and the low-temperature conductive part is configured to be insertable / removable with respect to the inside of the room temperature coating part,
The coefficient of static friction of the surface of the coating layer to the pipe-like structure, cold-insulated superconducting cable according to claim and this is 0.3 or less.   The said normal temperature coating | coated part is arrange | positioned inside the said normal temperature side electric insulation layer and the outer side of the said heat insulation pipe | tube, and is provided with the normal conducting shunt conductor which shares an abnormal time electric current. Room-temperature insulated superconducting cable. Outer peripheral contour of the longitudinal section of the coating layer, according to claim 1 or claim, characterized in that the contact area between the pipe-like structure on the surface of the coating layer is formed in an uneven shape so as to be smaller 2. A room-temperature insulated superconducting cable according to 2. The room temperature insulated superconducting cable according to claim 3 , wherein the outer peripheral outline is sinusoidal. The room temperature insulation type superconducting cable according to claim 3 , wherein the outer peripheral contour line has a sawtooth wave shape. A conductor portion formed by forming a superconducting conductor layer on the outer periphery of the former, a heat insulating tube that accommodates the conductor portion therein and maintains the conductor portion at a cryogenic temperature, and a coating layer formed on the outer periphery of the heat insulating tube; A process A for producing a low-temperature conductive part having
Step B for producing a room temperature coating part having a pipe-like structure having an inner diameter larger than the outer diameter of the low-temperature conductive part, and a room-temperature side electric insulating layer formed on the outer periphery of the pipe-like structure,
Inserting the low-temperature conductive part produced in the process A into the room temperature coating part produced in the process B; and
A method for manufacturing a room temperature insulated superconducting cable, comprising:
However, the coefficient of static friction of the surface of the coating layer with respect to the pipe-like structure is 0.3 or less.

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