JP5041133B2 - Manufacturing method of multi-core superconducting cable - Google Patents

Description

  The present invention relates to a multi-core batch type superconducting cable accommodated in a heat insulating tube in a state where a plurality of cable cores are twisted together. In particular, even when the cable core is cooled by the refrigerant filled in the heat insulating tube and causes thermal contraction, the thermal contraction can be sufficiently absorbed and an excessive stress can be prevented from being generated in the cable core. The present invention relates to a single-core superconducting cable.

  The multi-core batch type superconducting cable includes a cable core having a superconducting layer and a heat insulating tube for housing the core. In such a multi-core batch type superconducting cable, in order to make the superconducting layer of the cable core into a superconducting state, the cable core is cooled by filling a heat insulating tube with a refrigerant such as liquid nitrogen after installation.

  When the cable core in the heat insulating tube is cooled to an extremely low temperature from room temperature (about 300 K) to about 80 K or less (about 77 K when the refrigerant is liquid nitrogen), the cable core shrinks by about 0.3%. For example, thermal contraction of about 30 cm occurs for every 100 m of cable.

  Normally, both ends of the multi-core batch type superconducting cable are provided with an intermediate connection portion that connects the cables, and a termination connection portion that connects the multi-core batch type superconducting cable and a power device disposed on the normal temperature side, The cable is fixed at both ends and in place. Therefore, in a multi-core cable in which a plurality of cable cores are twisted together, when the cable core contracts due to cooling, the cable core moves in a direction in which the twist is tightened because the cable core is fixed at least at both ends.

  As a result, the cable core generates stress in the axial direction of the cable and radial stress due to the lateral pressure. If such stress is excessive, the superconducting layer may be damaged and the multicore superconducting cable cannot function. There is.

  Therefore, conventionally, a multi-core batch type superconducting cable having a configuration for absorbing the heat shrinkage has been proposed. As a configuration for absorbing heat shrinkage, for example, a plurality of cable cores twisted so as to have a slack for absorbing heat shrinkage are accommodated in a heat insulating tube.

  As a means for giving looseness to the twist, for example, methods disclosed in Patent Document 1 and Patent Document 2 can be cited. In the twisting method disclosed in Patent Document 1, the cable cores are twisted together while an inclusion having a large thermal shrinkage is inserted into the center of the three-core cable cores. By inserting inclusions in this way, each cable core is twisted in a state where each cable core spreads in the radial direction compared to a state in which inclusions are not inserted and there is no looseness. be able to. When the cable core is cooled, the inclusions are also thermally contracted along with the thermal contraction of the cable core, so that the twisted three-core cable core is changed in a direction in which the twisted diameter is reduced, and the thermal contraction is performed. To absorb.

  In the twisting method disclosed in Patent Document 2, first, the cable cores are twisted together while arranging a tape-like spacer between the three cable cores. Next, before the twisted cable core is stored in the heat insulating tube, the spacer is removed, and the cable core is stored in the heat insulating tube in a state where the twist is loosened.

  In the twisting method disclosed in Patent Document 2, the spacer between the cable cores is removed before the cable core is housed in the heat insulation pipe. Therefore, the cable core housed in the heat insulation pipe is used as the spacer. A slack can be given to a twist, without being restrained. As a result, the twisted cable core can absorb heat shrinkage during cooling due to this slackness.

JP-A-9-134620 JP 2002-216555 A

  In the method of twisting the cable cores described above, when twisting the cable cores, a member and equipment for making the twists slack are separately required. In addition, in the process of manufacturing the cable, since a process of giving slack to the twist is necessary, there is a problem that the manufacturing line at the time of manufacturing the cable becomes long. In particular, in the twisting method disclosed in Patent Document 1, there is a problem that inclusions are required over the entire length of the cable and the cost is increased. In addition, in the method of Patent Document 2, even if the spacer is used repeatedly, a large facility for inserting and removing the spacer is required, and not only the production line for twisting the cable core is lengthened, There are complications.

  Moreover, since the heat insulation pipe | tube is normally comprised with the double corrugated pipe | tube, it is easy to extend to an axial direction. Therefore, when the cable is laid, if the cable is pulled, the heat insulation pipe may be stretched. At this time, when the cable core twisted with a slack is accommodated in the heat insulation pipe, when the heat insulation pipe extends in this way, the cable core accommodated in the heat insulation pipe is pulled from one end side to become loose. Will disappear. As a result, when the cable core is cooled, the cable core cannot sufficiently absorb heat shrinkage, and the above-described excessive stress is generated in the cable core.

  Therefore, conventionally, a tension member has been provided on the outer periphery of the heat insulation pipe in order to prevent the heat insulation pipe from extending during installation. However, the work of providing the tension member is complicated, time-consuming, and expensive. Moreover, there is a problem that the entire diameter of the cable is increased by the amount of the tension member.

  By the way, in the twisting method disclosed in Patent Document 1 and Patent Document 2 described above, the cable core is loosened so that the amount of looseness of the cable core is uniform over the entire length of the cable core. Is given.

  However, the cable core normally supplies the refrigerant from one end side of the heat insulating pipe and discharges the refrigerant from the other end side, and the cable core is sequentially cooled from the refrigerant inlet toward the refrigerant outlet. Therefore, the temperature of the refrigerant on the refrigerant inlet side and the refrigerant outlet side is different. When the cable core is cooled in this way, the temperature distribution in the length direction of the cable core is not uniform, and the amount of thermal shrinkage of the cable core also varies in the length direction.

  That is, the portion of the cable core cooled on the refrigerant inlet side has a large amount of heat shrinkage because the refrigerant temperature is the lowest. On the other hand, in the portion cooled on the refrigerant outlet side of the cable core, the refrigerant and the cable core are heat-exchanged from the inlet to the outlet, so the refrigerant temperature becomes higher than the inlet side, and the amount of heat shrinkage Is smaller than the entrance side.

  As a result, even if the cable core is loosened, the cable core has a behavior in the length direction because the amount of heat shrinkage of the cable core is not uniform in the cable length direction. This behavior of the cable core also leads to the behavior at the connection portion of the cable, and stress concentration may occur at the end portion of the cable core, leading to damage.

  In particular, if the amount of twist in the cable core is made approximately equal in the length direction of the cable core, the cable core at the location where the heat shrinkage on the refrigerant inlet side is large will shrink first until there is no slack. And As described above, when the refrigerant inlet side of the cable core is thermally contracted first, a portion of the cable core where the temperature is high on the refrigerant outlet side is pulled to the refrigerant inlet side, and the cable core moves. The movement of the cable core is such that when cooling on the refrigerant outlet side is completed, the refrigerant inlet side of the cable core is pulled toward the refrigerant outlet side. As described above, the cable core exhibits a complicated behavior during cooling. In particular, when a connection portion that is not fixed is provided, the cable core or the superconducting wire may be damaged by this behavior.

  As described above, the present invention provides a slack that can sufficiently absorb the heat shrinkage of the twisted cable core when cooling the superconducting cable without complicating the facilities for forming the slack in twisting the cable core. The main object is to provide a method of manufacturing a multi-core superconducting cable that can be provided.

  In addition, the present invention provides a cable for cooling a cable core by arbitrarily setting the amount of cable core twist for each end of each cable in accordance with the required heat shrinkage of the cable core. Another object of the present invention is to provide a multi-core superconducting cable that can minimize the amount of movement of the core in the longitudinal direction and a method of manufacturing the same.

  Another object of the method of manufacturing a multi-core batch type superconducting cable according to the present invention is to allow a cable core to be laid without forming a tension member, and to surely form a cable core twist. .

  The manufacturing method of the multi-core batch type superconducting cable of the present invention in which the outer periphery of a plurality of twisted cable cores is covered with a heat insulating tube, the plurality of cable cores twisted together without slack, and a predetermined amount of slack in the cable core twist When the cable core is covered with the heat insulation tube, the end of the cable core has a predetermined heat shrinkage required when the cable core is cooled from at least one end side of the heat insulation tube. A first step in which the length exceeds the length, and after this first step, by pushing at least the length of the heat shrinkage of the cable core coming out of the heat insulation pipe into the heat insulation pipe, And a second step of causing the cable core to have a slack that absorbs heat shrinkage during cooling.

  In the first step of the present invention, twisting a plurality of cable cores without slack means intentionally twisting without slack so as to absorb heat shrinkage, and there is a gap between each cable core. May occur.

  Further, the predetermined amount of heat shrinkage required when the cable core is cooled refers to the amount of shrinkage that provides a slack amount that can absorb the heat shrinkage that causes the tension acting on the cable core to be equal to or less than the allowable tension when the cable is cooled. . Therefore, the slack may be formed so that no stress is generated even when heat shrinks, or the slack may be formed so that an allowable stress is generated. The allowable stress can be set according to the characteristics of the cable.

  Furthermore, in the present invention, the length of the cable core protruding from the end of the heat insulating tube is equal to or longer than the length of the required predetermined heat shrinkage. The length of the cable core protruding from the heat insulating tube is This is because it usually includes not only the length required for heat shrinkage but also the length required for the cable core connection process.

  When the cable core is pushed into the heat insulating tube in the second step of the present invention, the cable core is pushed in while loosening in the direction in which the twist of the core spreads. In other words, most of the twisted cable cores meander while curving like a wave, so when the twisted cable core is pushed into the heat insulating tube, each core has a bending diameter. The cable core, which is deformed in a decreasing direction and twisted, moves in a direction in which the twist spreads outward in the radial direction.

  In addition, the length of the cable core taken out from the heat insulation pipe in the first step should be longer than the length of the total heat shrinkage of the cable core that heat-shrinks in the heat insulation pipe during cooling from only one opening of the heat insulation pipe. Or you may make it take out predetermined length from the both ends opening part of a heat insulation pipe | tube. In this case, a predetermined length can be obtained so that the total length of the protruding lengths is equal to or greater than the total heat shrinkage. For example, one length may be longer than the other length or the same length.

  In addition, the first step in the method of manufacturing a multicore superconducting cable in which the outer circumferences of a plurality of twisted cable cores of the present invention are covered with a heat insulating tube can include the following steps.

  A step of forming a heat insulating tube having an inner diameter that allows a predetermined amount of slack to be twisted in the cable core, a step of twisting a plurality of cable cores without slack, a heat insulating tube is installed, and the inside of the installed heat insulating tube And housing the plurality of twisted cable cores so that a length equal to or longer than the heat shrinkage amount comes out from at least one end side of the heat insulating tube.

  That is, the process of forming the heat insulation pipe and the process of twisting the cable core without slack are performed separately.First, the heat insulation pipe is laid, and the plurality of twisted cable cores are placed inside the laid heat insulation pipe. The heat shrinkage amount is accommodated so that the length of the heat shrinkage tube comes out from at least one end side of the heat insulating tube.

  In addition, when accommodating the cable core twisted together in the inside of a heat insulation pipe | tube, you may make it pull in a cable core in the inside of a heat insulation pipe | tube, or may push it in.

  The above-described superconducting cable manufacturing method of the present invention can process the cable core with slackness even after the cable is manufactured or after the cable is laid, so it is necessary to provide the cable core with a slack when the cable is manufactured. Disappear. As a result, the cable core can be easily manufactured without increasing the length of the cable manufacturing line, increasing the number of facilities, and making the manufacturing line complicated. it can.

  Also, in the past, the cable core was already slackened before laying the cable, so it was necessary to fix the heat insulation pipe with a tension member or the like so that the slack of the twist was not lost when laying the cable. . However, according to the manufacturing method of the present invention, it is possible to make the twist loose after laying, so that the tension members are unnecessary or the number of tension members can be reduced. As a result, in the manufacturing method of the present invention, it is possible to apply a tensile force to the cable core together with the heat insulating tube, and it is possible to reduce the diameter of the entire cable and make it compact. In addition, when the tension member is no longer needed, the space that has become unnecessary can be used for the vacuum part of the heat insulation pipe, and this vacuum part can be thickened. Reduction is possible.

  In the manufacturing method of the present invention, when the heat insulating tube and the twisted cable core are separately formed and the twisted cable core is stored in the heat insulating tube, the heat insulating tube and the twisted cable core are installed. After being separately transported to the site and laying the heat insulation pipe, the cable core can be drawn into the heat insulation pipe. In this case, since the heat insulation pipe and the cable core can be individually transported to the laying site, even if the vacuum state of the heat insulation pipe is not maintained, it is confirmed that the vacuum state is not maintained in the heat insulation pipe. Can be found before storage in the cable core, so the cable core is not wasted.

  Further, when the cable is laid, if the heat insulation pipe is buried in the ground and the cable core is drawn into the heat insulation pipe, the heat insulation pipe can be used as a laying path.

  By the way, since the cooling temperature of the cable core differs with a temperature gradient in the longitudinal direction, the amount of heat shrinkage is assumed as if the entire length of the cable core is thermally contracted at a constant cooling temperature (coolant inlet side temperature) as in the past. The amount of heat shrinkage is actually smaller than the length when converted. Therefore, in the manufacturing method of the multi-core batch type superconducting cable of the present invention, the total amount of pushing the cable core into the heat insulating tube is the amount of heat shrinkage or allowable stress (allowable tension) of each part of the cable core corresponding to each cooling temperature. It is preferable to determine in consideration.

  Furthermore, in the manufacturing method of the multi-core batch type superconducting cable of the present invention, the pushing amount of the cable core into the heat insulating tube is such that the cable core is pushed into one end side of the heat insulating tube which becomes the refrigerant inlet side when the superconducting cable is cooled. It is preferable that the amount be equal to or greater than the pushing amount of the cable core on the other end side of the heat insulating pipe serving as the refrigerant outlet side.

  Thus, by determining the amount of pushing the cable core into the heat insulation pipe based on the direction of refrigerant injection at the time of cooling, the cable core portion that undergoes thermal contraction due to the temperature drop first during cooling is twisted in the radial direction. The amount of slack in the radial direction of the portion having a small amount of heat shrinkage can be reduced, so that the movement of the cable core in the length direction accompanying the heat shrinkage can be suppressed.

  Further, in the method for manufacturing a multi-core batch type superconducting cable of the present invention, the side where the pushing amount of the cable core into the heat insulating tube is large is set as the refrigerant inlet side for supplying the refrigerant into the heat insulating tube, and the amount of pushing into the heat insulating tube is small. The side may be the refrigerant outlet side.

  In this way, by determining the refrigerant injection direction during cooling based on the amount of pushing the cable core into the heat insulation tube, the cable core portion that undergoes a large thermal contraction due to a decrease in temperature first during cooling may be used in the radial direction. Since the amount of twist looseness can be increased and the amount of twist looseness in the radial direction of the portion having a small amount of heat shrinkage can be reduced, movement in the length direction of the cable core accompanying heat shrinkage can be suppressed.

  As described above, by increasing the amount of twist slack in the portion with a large amount of heat shrinkage compared with the portion with a small amount of heat shrinkage, the cable core shrinks almost in the radial direction during the heat shrinkage. The behavior toward is small.

  As described above, in the present invention, the amount of twist slack that absorbs heat shrinkage can be adjusted in accordance with the temperature gradient of the refrigerant, and therefore the movement of the entire cable core in the length direction can be minimized. As a result, the amount of movement of the cable core at the cable connecting portion can be made as small as possible to prevent damage due to the behavior of the cable core.

  In addition, the multicore superconducting cable in which the outer periphery of a plurality of twisted cable cores of the present invention is covered with a heat insulating tube is a twist for the cable core in the heat insulating tube to absorb the thermal contraction of the cable core during cooling. The amount of looseness of the slack in the radial direction of the heat insulating tube is different in the length direction of the cable.

  The twisted amount of the twisted cable core is made different in the length direction of the cable. Therefore, the portion where the heat shrinkage of the cable core is large increases the amount of looseness of the twist and the portion where the heat shrinkage is small. Can reduce the amount of loosening of the twist.

  That is, by increasing the amount of twist looseness in the portion having a large amount of heat shrinkage, the cable core can only move in the radial direction during heat shrinkage, and the movement in the length direction can be minimized.

  As a result, the behavior in the length direction due to the thermal contraction of the cable core can be minimized, and damage due to the behavior of the cable core can be prevented.

  In particular, the amount of slack in the radial direction of the heat insulation pipe of the cable core is preferably such that the amount of slack near the refrigerant inlet supplying the refrigerant into the heat insulation pipe is greater than the amount of slack near the refrigerant outlet. Since the cable core near the refrigerant inlet is cooled by the lowest temperature refrigerant, the amount of heat shrinkage is the largest. Therefore, if the amount of twist of the cable core in the portion having a large heat shrinkage is set larger than that in the portion having a small heat shrinkage, the behavior in the length direction of the cable core can be reduced.

  In the method for manufacturing a multi-core batch type superconducting cable and the multi-core batch type superconducting cable of the present invention, the number of twisted cable cores may be any number such as 2-core, 3-core, and 4-core.

  In the manufacturing method of the multi-core batch type superconducting cable of the present invention, the cable core is twisted together in a slack-free state at the time of cable manufacturing, so that the manufacturing line becomes longer or the number of facilities increases and the manufacturing line becomes complicated. Cable can be easily manufactured. Moreover, in the present invention, the cable core can be surely slackened.

  Furthermore, in the method of manufacturing the multi-core batch type superconducting cable of the present invention, the cable core can be laid without twisting, and then the cable can be laid without providing a tension member. There are cases where it is possible. As a result, the slack for absorbing the thermal contraction of the cable core can be surely held while the tension member is not necessary and before cooling after laying.

  Therefore, when the tension member can be eliminated, the cost can be reduced, and the overall diameter of the cable can be reduced and the size can be reduced. In addition, when the overall diameter of the cable is the same as the conventional size, the diameter of the heat insulating tube can be increased to increase the radial thickness of the vacuum part of the heat insulating tube, so that the heat insulating effect can be improved. .

  Hereinafter, an embodiment of a method for manufacturing a multi-core superconducting cable of the present invention will be described. In the present embodiment, the manufacturing of the heat insulating tube and the operation of twisting the three cores are separately performed at the factory, and the operation of storing the cores of the three cores in the heat insulating tube is performed at the installation site. A method for manufacturing the superconducting cable will be described. The work of giving the cable core twist the slack that absorbs the thermal contraction of the cable core when the cable core is cooled is performed at the installation site.

  As shown in FIG. 2, a multi-core batch type superconducting cable 100 of the present invention obtained by the method for manufacturing a multi-core batch type superconducting cable of the present invention has a three-core cable core 10 and a heat insulation for housing the cable core 10. It consists of a tube 20.

  Each cable core 10 includes a former (core material) 11, a superconducting conductor layer 12, an insulating layer 13, a superconducting shield layer 14, and a protective layer 15 in order from the center.

  On the other hand, the heat insulating tube 20 is a double tube including an inner tube 21 and an outer tube 22, and a vacuum heat insulating layer is formed between the inner and outer tubes 21 and 22. Both the inner tube 21 and the outer tube 22 are corrugated tubes. A so-called super insulation (trade name) in which a plastic mesh and a metal foil are laminated is disposed in the vacuum heat insulating layer. Further, an anticorrosion layer 23 and a protective coating layer (not shown) are sequentially formed outside the outer tube.

  The inside of the inner pipe 21 in the heat insulating pipe 20 serves as a refrigerant flow path that is filled with a refrigerant such as liquid nitrogen that cools the cable core 10.

  The multi-core collective superconducting cable of the present embodiment is housed in the heat insulating tube 20 in a state where a plurality of cable cores 10 having the above-described configuration are twisted together.

  Next, a method for manufacturing the multi-core batch type superconducting cable will be described with reference to FIG. In the present embodiment, as described above, the process of twisting the three cable cores and the process of manufacturing only the heat insulation pipe are performed at the factory, and the process after the process of storing the twisted cable cores inside the heat insulation pipe is laid. Perform on site.

  FIG. 1 is a schematic explanatory view showing a manufacturing process of a multi-core batch type superconducting cable of the present invention, and the process A conveys a heat insulating pipe manufactured separately in a factory and a cable core twisted together to a laying site, The process of storing the cable core twisted inside the installed heat insulation pipe in the heat insulation pipe, the process B is a cable installed in order to push the cable core coming out from the opening of the heat insulation pipe into the heat insulation pipe. The step of placing a jig at the end of the core, step C, is a step of pushing the cable core into the heat insulating tube with the jig.

<Process A for storing twisted cable core in heat insulation pipe>
First, the process A which accommodates the twisted cable core in a heat insulation pipe | tube is demonstrated.

  (1) A double insulation pipe 20 is manufactured in a factory. The heat insulating tube 20 first forms the inner tube 21. The inner pipe 21 is made of corrugated pipe by welding its end while continuously deforming plate-like stainless steel into a tubular shape. The inner diameter of the inner pipe 21 (the minimum diameter of the corrugated pipe) is an inner diameter that allows the cable core 10 to be twisted with a predetermined amount of slack. Here, the predetermined amount of slack refers to the amount of slack that allows the cable core 10 in the heat insulating tube 20 to sufficiently absorb heat shrinkage during cooling.

  The outer circumference of the inner pipe 21 of the heat insulation pipe 20 is covered with super insulation, and the outer pipe 22 is formed so as to cover the outer circumference. The outer tube 22 is also processed into a corrugated tube by continuously welding plate-like stainless steel and welding its end while deforming it into a tubular shape.

  (2) Twist the three-core cable cores 10 in a factory without any slack.

  (3) The twisted cable core 10 is drawn into the inner tube 21 of the heat insulating tube 20. A protective tube 24 made of a corrugated tube is attached to the end of the heat insulating tube 20. The protective tube 24 covers the flange 25 fixed to the end of the heat insulating tube 20 and the vacuum port 26 attached to the flange 25. When the cable core 10 is housed in the heat insulating tube 20, only one end portion of the heat insulating tube 20 is illustrated in FIG. 1, but the cable core 10 is protruded from both ends of the heat insulating tube 20.

  This protrusion amount is projected so that the total of both protrusion amounts is equal to or longer than a predetermined heat shrinkage length required for cooling the cable core 10 accommodated in the heat insulating tube 20. In this embodiment, when the superconducting cable is cooled, the protruding amount (pushing amount) of the cable core 10 at one end of the heat insulating tube 20 that is the refrigerant inlet side is the other end of the heat insulating tube 20 that is the refrigerant outlet side. The amount of protrusion (push-in amount) of the cable core 10 is set to be equal to or greater than Alternatively, the side where the pushing amount of the cable core into the heat insulating tube is large is the refrigerant inlet side for supplying the refrigerant into the heat insulating tube, and the side where the pushing amount is small into the heat insulating tube is the refrigerant outlet side.

  Further, the inner diameter of the inner pipe 21 of the heat insulating pipe 20 (the minimum diameter of the corrugated pipe) is an inner diameter that allows the cable core 10 to have a predetermined amount of slack. Here, the predetermined amount of slack refers to the amount of slack that allows the cable core 10 in the heat insulating tube 20 to sufficiently absorb heat shrinkage during cooling.

  (4) When the process of housing the cable core 10 in the heat insulation pipe 20 is completed, the cable core 10 is projected from one end of the heat insulation pipe 20 as shown in Step A of FIG. In step A of FIG. 1, the end of the cable core 10 is covered with the protective tube 24. In the present embodiment, the cable core 10 protruding from the end portion of the heat insulating tube 20 is pushed in while leaving the length necessary for the cable connection process in the subsequent cable core pushing process.

  As described above, the protruding amount of the cable core 10 from the heat insulating tube 20 may be protruded from both ends, but the total amount of heat shrinkage of the cable core 10 may be protruded from one end side. . It is easier to put the cable core 10 into the heat insulating tube 20 when protruding from both ends.

  When the cable core 10 is protruded from both ends of the heat insulating tube 20, the amount of protrusion is larger than the amount of protrusion of the cable core 10 from the end of the heat insulating tube 20 on the refrigerant inlet side than the amount of protrusion on the refrigerant outlet side. However, the amount of protrusion on the refrigerant outlet side may be increased or the same length, and the amount of protrusion can be determined in accordance with the design of the superconducting cable.

  Also, when the twisted cable core 10 is stored inside the heat insulation tube 20, the cable core 10 twisted without slack is covered with the inner tube 21 of the heat insulation tube 20, and then the outer tube 22 is formed. Also good. In this case, in the step of covering the cable core 10 with the inner tube 21, the end portion of the inner tube 21 is welded while being continuously deformed into a tubular shape, and further processed into a corrugated tube.

  Then, the outer periphery of the inner tube 21 of the heat insulating tube 20 is covered with super insulation, and the outer tube 22 is covered on the outer periphery. Even in the step of covering the inner tube 21 with the outer tube 22, the plate-shaped stainless steel is continuously welded while being deformed into a tubular shape, and further processed into a corrugated tube.

<Process B for placing a pushing jig on the end of the twisted cable core>
After step A is finished, the cable core 10 protrudes from one end of the heat insulating tube 20, and then the protective tube 24 is removed and pushed into the end of the cable core 10 protruding from the opening of the heat insulating tube 20. The jig 4 is arranged (process B).

  The pushing jig 4 is disclosed in a simplified manner in FIG. 1, but at the end of the cable core 10, a cylindrical portion 41 covering the length for connection processing is provided at one end of the cylindrical portion 41. It has a cylindrical clamping part 42 that is fixed and clamps a part of the cable core 10. And although not shown in figure, this clamping part 42 and the cylinder part 41 are supported, the support part which can move to the length direction of a cable is provided, and this support part is moved toward the inside of the heat insulation pipe | tube 20. As a result, the cable core 10 is pushed in.

  The sandwiching portion 42 and the tubular portion 41 are inserted from the end of the cable core 10 and the tubular portion 41 covers the length for the connection processing of the cable core 10, and the sandwiching portion 42 is connected to a predetermined portion of the cable core 10. Fix at the position where the push-in amount can be obtained. The cable core 10 is pushed into the inside of the heat insulating tube 20 by moving the holding part 42 toward the inside of the heat insulating tube 20.

<Process C for pushing the end of the twisted cable core into the heat insulating tube>
Then, from the state of step B in FIG. 1, the cable core 10 is pushed into the heat insulating tube using the pushing jig 4 (step C). In this pushing step, the cable core 10 having the length of the heat shrinkage amount coming out of the heat insulating tube 20 was pushed into the heat insulating tube 20, and the length necessary for cable connection processing was protruded from the heat insulating tube 20. Put it in a state.

  When the cable core 10 is pushed into the heat insulating tube 20, the cable core 10 is pushed inside the heat insulating tube 20 while being loosened in the direction in which the twist is spread, as shown in the state diagram of step C in FIG.

  By pushing the cable core 10, the cable core 10 in the heat insulating tube 20 can have a slack that absorbs heat shrinkage during cooling.

  In the cable core pushing process, the pushing jigs 4 are provided at both ends of the heat insulating tube 20, and the pushing is performed.

  As described above, by manufacturing the multi-core batch type superconducting cable by the manufacturing method of the present embodiment, the cable core is twisted in a slack-free state at the time of cable manufacturing, so the manufacturing line becomes longer and the number of facilities increases. Thus, the cable can be easily manufactured without complicating the production line. Moreover, in the present invention, the cable core can be surely slackened.

  Furthermore, since the cable core can be laid in a twisted state without slack, the twist can be slackened, so that the tension member can be dispensed with. If the tension member is dispensed with, the cost can be reduced. The overall cable diameter can be reduced and the cable can be made compact.

  The multicore superconducting cable of the present invention can be suitably used for power supply such as AC power transmission or DC power transmission.

It is explanatory drawing which shows the manufacturing process of the manufacturing method of this invention multi-core package type superconducting cable, Process A is the process of accommodating the twisted cable core in a heat insulation pipe, Process B is pushed into the edge part of the twisted cable core. The process of arranging the jig for use, process C shows the process of pushing the end of the twisted cable core into the heat insulating tube. It is sectional drawing of the multi-core lump superconducting cable obtained with the manufacturing method of the multi-core lump superconducting cable of this invention.

Explanation of symbols

100 Multi-core superconducting cable
10 Cable core
11 Former 12 Superconducting conductor layer 13 Insulating layer
14 Superconducting shield layer 15 Protective layer
20 Insulated pipe
21 Inner tube 22 Outer tube 23 Anticorrosion layer 24 Protective tube
25 Flange 26 Vacuum port
4 Pushing jig 41 Tube part 42 Nipping part

Claims (4)

A method of manufacturing a multi-core superconducting cable in which the outer periphery of a plurality of twisted cable cores is covered with a heat insulating tube,
Cover multiple cable cores twisted together without slack with a heat insulating tube having an inner diameter that allows the cable core twist to give a specified amount of slack. A first step in which the cable core comes out of at least a predetermined heat shrinkage length required for cooling from at least one end of the tube;
After this first step, the cable core in the heat insulation pipe absorbs the heat shrinkage at the time of cooling by pushing at least the length of the heat shrinkage amount of the cable core coming out of the heat insulation pipe into the heat insulation pipe. A method of manufacturing a multi-core batch type superconducting cable, comprising: a second step of imparting slackness. The first step includes
Forming a heat insulating tube having an inner diameter capable of giving a predetermined amount of slack to the twist of the cable core;
A process of twisting a plurality of cable cores without slack,
A step of laying a heat insulation pipe, and housing the plurality of twisted cable cores inside the laid heat insulation pipe so that a length equal to or longer than the heat shrinkage amount comes out from at least one end side of the heat insulation pipe. The manufacturing method of the multi-core batch type superconducting cable of Claim 1 characterized by the above-mentioned.   When cooling the superconducting cable, the amount of pushing the cable core on one end of the heat insulation pipe that is the refrigerant inlet side should be greater than the amount of pushing the cable core on the other end of the heat insulation pipe that is the refrigerant outlet side. The method of manufacturing a multi-core batch type superconducting cable according to claim 1 or 2, wherein   2. The side where the amount of pushing the cable core into the heat insulating tube is large is the refrigerant inlet side for supplying the refrigerant into the heat insulating tube, and the side where the amount of pushing into the heat insulating tube is small is the refrigerant outlet side. Or the manufacturing method of the multi-core package type superconducting cable of Claim 2.

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