JP2016226143A - Terminal connector for cryogenic cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal connector for a cryogenic cable capable of reducing heat intrusion from the outside to the inside via a conductor lead-out part.SOLUTION: The terminal connector comprises: a terminal part of a cryogenic cable; a refrigerant tank in which a liquid refrigerant for cooling the terminal part of the cryogenic cable is stored, the terminal part of the cryogenic cable is disposed and a liquid refrigerant layer and a gas refrigerant layer are formed; and a conductor lead-out part of which the lower end is immersed in the liquid refrigerant and connected to a conductor of the cryogenic cable and the upper end is led out to a normal-temperature part via the gas refrigerant layer. In the gas refrigerant layer of the refrigerant tank, a plurality of insulative baffle plates are disposed around the conductor lead-out part for partitioning the gas refrigerant layer at predetermined intervals in a direction of extension of the conductor lead-out part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a terminal connection part of a cryogenic cable such as a superconducting cable.

  Conventionally, a superconducting cable using a superconducting wire that becomes a superconducting state at an extremely low temperature as a conductor is known. The superconducting cable is expected as a power cable capable of transmitting a large current with a low loss, and is being developed for practical use.

  The superconducting cable has a structure in which a single-core or multiple-core cable core is accommodated in a heat insulating tube. The cable core includes, for example, a former, a superconducting conductor layer, an electrical insulating layer, a cable shield layer, and a protective layer in order from the center. The heat insulation pipe includes an inner pipe (hereinafter referred to as “heat insulation inner pipe”) in which the cable core is accommodated and filled with a refrigerant (for example, liquid nitrogen), and an outer pipe (hereinafter referred to as “heat insulation outer pipe”) covering the outer periphery of the heat insulation inner pipe. Have Between the heat insulating inner tube and the heat insulating outer tube, a vacuum state is set for heat insulation.

  In the terminal connection part of the superconducting cable, the terminal part of the superconducting cable is accommodated in a low temperature container that is a low temperature part, and the conductor of the superconducting cable (for example, the superconducting conductor layer) is drawn out to the room temperature part through the conductor lead-out part. The cryogenic container accommodates the terminal portion of the superconducting cable in communication with the heat-insulated inner tube of the superconducting cable and contains a refrigerant tank filled with a refrigerant such as liquid nitrogen during operation, a refrigerant tank, and heat to the refrigerant tank. In order to reduce intrusion, it has a double structure consisting of a vacuum chamber that is evacuated during operation. In addition, as a room temperature part that forms a layer (room temperature layer) of temperature (for example, room temperature) in the installation environment of the terminal connection part so as to surround the conductor drawing part drawn to the outside of the refrigerant tank at the upper part of the refrigerant tank A soot tube is provided.

  A liquid refrigerant layer composed of a liquid refrigerant such as liquid nitrogen and a gas refrigerant layer are formed inside the refrigerant tank. The conductor lead-out portion passes through the gas refrigerant layer from the liquid refrigerant layer at a cryogenic temperature (for example, liquid nitrogen is liquid refrigerant, −196 ° C. at atmospheric pressure) filled with a liquid refrigerant such as liquid nitrogen, Part) at room temperature. As a result, a temperature distribution is generated in the gas refrigerant layer, and in the refrigerant layer, the temperature of the gas refrigerant layer changes from the lower end of the cryogenic liquid refrigerant layer to the upper end of the normal pipe side Function as.

  In such a configuration of the terminal connection part, the gas refrigerant layer of the refrigerant tank is adjacent to the normal temperature layer of the normal temperature part via the conductor extraction part, so that it is easy to receive heat intrusion via the conductor extraction part and the outside of the refrigerant tank. From inside, heat flows in toward the liquid refrigerant layer in a cryogenic environment. When this heat inflow is large, the loss amount of liquid nitrogen in the liquid refrigerant layer in which the lower end portion of the conductor lead-out portion is immersed becomes large, and the loss when cooling the terminal portion of the superconducting cable by the liquid refrigerant becomes large.

  On the other hand, for example, as shown in Patent Document 1, a stress cone is provided on the outer periphery of the conductor lead-out portion in the refrigerant tank, and the liquid refrigerant layer of the refrigerant tank and the liquid refrigerant are surrounded by the stress cone. A configuration in which one baffle plate is provided at any one of the interface and the gas refrigerant layer is known. This baffle plate insulates the cryogenic temperature side and the room temperature side in the temperature gradient portion so as to prevent heat from entering the liquid refrigerant layer from the room temperature side.

JP 2012-217334 A

  As described above, in the conventional terminal connection part that draws the current from the conductor of the terminal part of the superconducting cable of the liquid refrigerant layer to the room temperature part through the gas refrigerant layer, through the conductor extraction part arranged in the refrigerant tank, There has been a demand for realizing more effective heat penetration from the outside to the inside via the conductor lead-out portion.

  An object of the present invention is to provide a highly reliable terminal connection portion of a cryogenic cable that can reduce heat intrusion from outside to inside through a conductor lead portion.

The terminal connection part of the cryogenic cable according to the present invention is a terminal part of the cryogenic cable,
A refrigerant tank in which liquid refrigerant for cooling a terminal portion of the cryogenic cable is stored, and a liquid refrigerant layer in which the terminal portion of the cryogenic cable is disposed and a gas refrigerant layer continuous on the liquid refrigerant layer; ,
A conductor lead-out portion whose lower end is immersed in the liquid refrigerant and connected to the conductor of the cryogenic cable, and whose upper end is drawn out to the room temperature portion through the gas refrigerant layer;
Have
The gas refrigerant layer of the refrigerant tank is disposed around the conductor extraction portion, and has a plurality of insulating baffle plates that divide the gas refrigerant layer at predetermined intervals in the extending direction of the conductor extraction portion. The structure is provided.

  According to the present invention, the gas refrigerant layer is partitioned into a plurality of layers by the plurality of baffle plates arranged around the conductor lead-out portion in the gas refrigerant layer of the refrigerant tank, so that from the outside to the inside through the conductor lead-out portion. Thermal intrusion can be reduced and a highly reliable cryogenic cable termination connection can be realized.

The figure which shows the termination | terminus connection part which concerns on one embodiment of this invention. The expanded partial sectional view which shows the gaseous refrigerant | coolant layer part of a refrigerant tank in FIG. The perspective view of the partition unit with which it uses for description of the baffle plate of the termination | terminus connection part which concerns on one embodiment of this invention. The perspective view which shows another example of the partition unit with which it uses for description of the baffle plate of the termination | terminus connection part which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a termination connection unit 1 according to an embodiment of the present invention. For convenience of explanation, the side where the superconducting cable 10 as a cryogenic cable 10 is introduced will be described as the rear end side (right side in FIG. 1), and the opposite side will be described as the front end side (left side in FIG. 1).

  As shown in FIG. 1, the terminal connection portion 1 includes a terminal portion of the superconducting cable 10, a cryogenic container 20, a conductor extraction portion 30, a soot tube 40, a shield energization portion 50, a partition unit 70, and the like. The terminal portion of the superconducting cable 10 is housed in a predetermined state in the cryogenic container 20 (specifically, the refrigerant tank main body 21A of the refrigerant tank 21), and the conductor current of the superconducting cable 10 is supplied to the power device or the like through the conductor lead-out part 30. It is pulled out to the system side. Further, the cable shield layer 114 of the superconducting cable 10 is grounded via the shield energization unit 50.

  The superconducting cable 10 is a single-core superconducting cable in which a single-core cable core 11 is accommodated in a heat insulating tube 12. The superconducting cable 10 may be a three-core batch type three-phase superconducting cable accommodated in the heat insulating tube 12 in a state where three cable cores 11 are twisted together.

  The cable core 11 includes, for example, a former 111, a superconducting conductor layer 112, an electrical insulating layer 113, a cable shield layer 114, a protective layer 115, and the like in order from the center.

  In the terminal portion of the superconducting cable 10, the cable core 11 is stepped, and each layer is exposed in order from the tip side. A connection electrode portion (hereinafter referred to as “electrode portion”) 13 that is electrically connected to the superconducting conductor layer 112 is disposed on the outer periphery of the superconducting conductor layer 112. A shield connection terminal 14 that is electrically connected to the cable shield layer 114 is disposed on the outer periphery of the cable shield layer 114. An electric field relaxation portion 15 such as a stress cone is disposed on the outer periphery of the electrical insulating layer 113 located between the electrode portion 13 and the shield connection terminal 14.

  The heat insulating tube 12 has a double tube structure including an inner heat insulating inner tube 121 and an outer heat insulating outer tube 122.

  The heat insulating inner pipe 121 accommodates the cable core 11 and is filled with a liquid refrigerant N (for example, liquid nitrogen) during operation. Thereby, the superconducting conductor layer 112 is maintained in a superconducting state. A space between the heat insulating inner pipe 121 and the heat insulating outer pipe 122 is kept in a vacuum state during operation for heat insulation.

  The cryogenic container 20 has a double structure including an inner refrigerant tank 21 and an outer vacuum tank 22.

  The refrigerant tank 21 has, for example, a hollow bottomed cylindrical shape, a refrigerant tank main body 21A that houses the terminal portion of the superconducting cable 10, and a conductor lead-out cylindrical part that introduces the conductor lead-out part 30 (hereinafter referred to as “drawer cylindrical part”). And a shield outlet 21 </ b> C for introducing the shield energization unit 50. The refrigerant tank main body 21A does not have to be integrally formed with a bottomed cylindrical shape, and the refrigerant tank main body 21A according to the present embodiment closes the opening on the front end side of the cylindrical portion with the disk-shaped front end portion 211. It is formed by doing. The bottomed cylindrical refrigerant tank 21 may be placed on a gantry (not shown) disposed in the vacuum tank 22, for example.

  The terminal part of the superconducting cable 10 is introduced into the refrigerant tank 21 from the rear end side (specifically, the rear end side of the refrigerant tank main body 21A). A heat insulating inner pipe 121 of the superconducting cable 10 is connected to the rear end portion 212 of the refrigerant tank 21. A liquid refrigerant (for example, liquid nitrogen) N is circulated and supplied to the refrigerant tank 21 by a refrigerant circulation device (not shown) during operation. The inside of the heat insulating inner pipe 121 communicating with the refrigerant tank 21 is also filled with the liquid refrigerant.

  In the refrigerant tank 21, the supplied liquid refrigerant N is stored, and the terminal portion of the superconducting cable 10 is cooled by the liquid refrigerant N. In the refrigerant tank 21, a liquid refrigerant layer made of a liquid refrigerant (for example, liquid nitrogen) is formed below the liquid surface NS of the liquid refrigerant N, and a gas made of a gas refrigerant (for example, gaseous nitrogen) AN is formed above the liquid surface NS. A refrigerant layer is formed. For example, by storing the liquid refrigerant N in the refrigerant tank 21, the liquid refrigerant layer of the liquid refrigerant N stored in the refrigerant tank 21 and the liquid refrigerant N are vaporized, and above the liquid refrigerant layer and the liquid refrigerant layer. A gas refrigerant layer of the gas refrigerant AN that is continuous with the gas refrigerant AN.

  Here, the gas refrigerant layer is formed inside the drawn cylindrical portion 21 </ b> B of the refrigerant tank 21. The lead-out cylindrical part 21 </ b> B is suspended from the upper part of the bottomed cylindrical refrigerant tank main body 21 </ b> A of the refrigerant tank 21 in a state where the insides thereof are communicated with each other. In general, a soot tube 40 called a normal temperature portion is fixed to the upper portion of the drawer tubular portion 21B in a state where the insides thereof are in communication with each other. A partition unit 70 having a plurality of baffle plates 71 for partitioning the gas coolant layer into a plurality of layers is disposed in the gas coolant layer in the drawer tubular portion 21B. Details of the partition unit 70 will be described later.

  The vacuum tank 22 has, for example, a hollow bottomed cylindrical shape, and includes a vacuum tank main body 22A that accommodates the refrigerant tank 21, a first cylindrical portion 22B that is suspended upward from the vacuum tank main body 22A, And a second cylindrical portion 22C that is spaced apart from the first cylindrical portion 22B and extends upward from the vacuum chamber main body portion 22A. In general, the second cylindrical portion 22C is generally referred to as a temperature gradient portion together with the drawer cylindrical portion 21B, the gas refrigerant layer in the drawer cylindrical portion 21B, and the like. The vacuum chamber main body 22A may not be integrally formed with a bottomed cylindrical shape, and the vacuum layer main body 22A of the present embodiment has a disk-shaped front end 221 with the opening on the front end side of the cylindrical portion. It is formed by closing with.

  The vacuum chamber 22 is positioned so that the extraction cylindrical portion 21B is positioned in the first cylindrical portion 22B and the shield outlet 21C is positioned below the second cylindrical portion 22C. The refrigerant tank 21 is arranged. A heat insulating outer tube 122 of the superconducting cable 10 is connected to the rear end portion 222 of the vacuum chamber 22.

  The first tubular portion 22B is disposed so as to surround the outer periphery of the drawer tubular portion 21B, and a soot tube 40 that is in airtight communication with the inside of the drawer tubular portion 21B is fixed to the upper portion of the first tubular portion 22B. Is done. The measurement pipe 61 and the shield energization part 50 are disposed in the second cylindrical part 22C.

  Since the shield outlet 21C in the refrigerant tank 21 is accommodated in the vacuum tank main body 22A of the vacuum tank 22, the shield energization part 50 and the measurement pipe 61 serving as a heat transfer path are introduced to the inside of the vacuum tank main body 22A. The Thereby, since it becomes easy to ensure the heat transfer path length for reducing heat intrusion, the length of the second cylindrical portion 22C can be minimized, and the terminal connection portion 1 can be downsized. Can do.

  The vacuum chamber 22 is evacuated by a vacuum pump (not shown) during operation and kept in a vacuum state. The space between the heat insulating inner tube 121 and the heat insulating outer tube 122 communicating with the vacuum chamber 22 is also maintained in a vacuum state.

  The conductor lead-out part 30 is a conductor for drawing a current from the superconducting cable 10 to the actual system. The conductor lead part 30 has a conductor lead bar made of, for example, a copper bar or a pipe. In addition, the structure of the conductor extraction part 30 is not limited to this, A well-known structure is applicable. One end of the conductor lead portion 30 (conductor lead bar) is connected to the electrode portion 13. The conductor lead-out part 30 is electrically connected to the superconducting conductor layer 112 of the cryogenic cable 10 through the electrode part 13, and the other end penetrates the soot pipe 40 in an airtight manner and is drawn out from the upper part of the soot pipe 40.

  Specifically, the lower end portion of the conductor lead-out portion 30 is connected to the terminal portion of the superconducting cable 10 through the electrode portion 13 while being immersed in the liquid refrigerant N in the refrigerant tank 21.

  Further, at the lower end portion of the conductor lead-out portion 30, an electric field relaxation portion (so-called stress cone) 62 is disposed on the outer periphery of the upper portion of the portion (lower end) connected to the electrode portion 13 in the conductor lead-out portion 30. The electric field relaxation part 62 exposes the upper part above the liquid surface of the liquid refrigerant N around the conductor lead-out part 30 in the refrigerant tank 21.

  The electric field relaxation portion 62 is a cylindrical member that relaxes the electric field of the current drawn from the electrode portion 13 and flowing through the conductor extraction portion 30, and the outer diameter thereof is smaller than the inner diameter of the extraction cylindrical portion 21B. It forms so that a clearance gap may be made between the inner peripheral surfaces of the extraction | drawer cylindrical part 21B.

  The conductor lead-out part 30 is immersed in the liquid refrigerant N at the lower end, the lower side of the central part on the lower end part is arranged in the lead-out cylindrical part 21B, and the upper side of the central part is arranged in the vertical tube 40 as a normal temperature part. The The upper end portion of the conductor lead-out portion 30 passes through the inside of the soot tube 40, penetrates the top end portion of the soot tube 40 in an airtight manner, and is exposed to the outside of the soot tube 40 so as to be electrically connectable.

  The conductor lead-out part 30 inside the lead-out cylindrical part 21B is arranged at a position spaced apart from the inner peripheral surface of the lead-out cylindrical part 21B. Here, the conductor lead-out portion 30 is disposed so as to be inserted through the inside of the lead-out cylindrical portion 21B on its axis.

  In addition, it is preferable that the conductor extraction part 30 has flexible conductors (not shown), such as a flat knitted copper wire, at least in part. Thereby, even if the position of the electrode part 13 moves in the horizontal direction (left and right direction in FIG. 1) due to thermal expansion and contraction of the cryogenic cable 10, the conductor lead-out part 30 is fixed to the refrigerant tank 21. Unlike the case, it is possible to prevent the fixed part from being damaged.

  The conductor lead-out portion 30 is loosely inserted into the plurality of baffle plates 71 of the partition unit 70 arranged in the lead-out cylindrical portion 21B of the refrigerant tank 21. Here, the baffle plate 71 will be described in detail together with the partition unit 70.

  FIG. 2 is an enlarged partial cross-sectional view showing a gas refrigerant layer portion of the refrigerant tank in FIG. 1, and FIG. 3 is a perspective view of a partition unit used for explaining a baffle plate of a terminal connection portion according to an embodiment of the present invention. FIG.

  As shown in FIG. 1 and FIG. 2, by installing a partition unit 70 in the gas refrigerant layer in the refrigerant tank 21, a plurality of baffle plates 71 are provided in the drawer tubular portion 21 </ b> B of the refrigerant tank 21. Around the lead-out part 30, the conductor lead-out part 30 is arranged at a predetermined interval in the extending direction. The plurality of baffle plates 71 (excluding the lowermost baffle plate 71) are installed in a region that is not insulated in the refrigerant tank 21 of the terminal connection portion 1. Note that the predetermined interval, which is the installation position of the baffle plate 71, is set by a temperature gradient based on the length of the vacuum chamber 22 along the conductor extraction portion 30 (the length of the cylindrical portion 22B on the outer peripheral portion of the extraction cylindrical portion 21B). Is done. If the length of the vacuum chamber 22 is long, the temperature gradient in the extending direction of the conductor lead-out portion 30 (the gradient of temperature decrease from the normal temperature at the upper end to the cryogenic temperature at the lower end) becomes smaller.

  As shown in FIGS. 2 and 3, the partition unit 70 connects the baffle plates 71 facing each other in the plurality of baffle plates 71 and the plurality of baffle plates 71 (for example, the baffle plates 71-1 to 71-3). And a connecting member 73 (for example, connecting members 73-1 and 73-2).

  The plurality of baffle plates 71 are an internal region where the gas refrigerant AN is filled in the refrigerant tank 21, that is, the gas refrigerant layer is the longitudinal direction of the conductor lead-out portion 30 and the longitudinal direction of the gas refrigerant layer (the direction in which the temperature gradient occurs). Into several layers.

  The baffle plate 71 is an annular flat plate made of plastic or other insulator and has heat insulation properties. The baffle plate 71 may be configured by a porous annular flat plate. The baffle plate 71 can reduce the intrusion heat from the front surface side (upper side) of the baffle plate 71 from moving to the region on the back surface (lower side), and can obtain a high cooling effect. In addition, since the baffle plate 71 does not have air permeability and water permeability, a minute ventilation hole penetrating vertically may be formed in order to allow the gas refrigerant AN to pass therethrough. Here, the baffle plate 71 is made of fiber reinforced plastics (FRP).

  In the baffle plate 71, the conductor lead-out portion 30 is penetrated through the central opening 712 at the center thereof. Further, a gap S1 is provided between the outer edge of the baffle plate 71 and the inner peripheral surface of the lead-out cylindrical portion 21B, and between the inner peripheral surface defining the central opening 712 and the conductor lead-out portion 30 in the baffle plate 71, respectively. The baffle plate 71 is formed in a shape provided with S2. The gap S1 is formed between the outer edge of the baffle plate 71 and the inner peripheral surface of the extraction cylindrical portion 21B in a state of being evenly spaced in the circumferential direction. Further, the gap S <b> 2 is formed at equal intervals in the circumferential direction by setting the center of the central opening 712 of the baffle plate 71 and the axis of the conductor lead-out portion 30 as the same axis. These gaps S1 and S2 can absorb contraction in the axial directions of the superconducting cable 10 and the refrigerant tank 21, and can also absorb contraction in the horizontal direction (radial direction) of the baffle plate 71 itself.

  The connecting member 73 (73-1, 73-2) is a state in which a plurality of baffle plates 71 arranged at a predetermined interval are insulated from each other and the baffle plates 71 opposed to each other at a predetermined interval. Connect.

  Here, the connecting member 73 is fixed to the baffle plate 71 at a portion where the shaft member 732 is inserted into the baffle plate 71 and a shaft member 732 such as a bolt inserted into a hole penetrating the front and back surfaces of the baffle plate 71. And a fastening member 734 such as a nut.

  Male screw portions are formed on the outer circumferences of both end portions of the shaft member 732 including the portions inserted into the baffle plate 71. The male screw portion is inserted into the hole portion of the baffle plate 71, and a nut as a fastening member 734 is screwed and fastened to the male screw portions located on both sides of the hole portion from the front and back sides of the baffle plate 71. At least one such connecting member 73 is installed in the circumferential direction of the baffle plate 71 between the baffle plates 71 facing each other, thereby connecting the baffle plates 71 facing each other.

  In the present embodiment, for each baffle plate 71, the baffle plates 71 that are respectively connected on the front and back surfaces are connected at a position where the connecting member 73 does not overlap in the connecting direction (the extending direction of the conductor leading portion 30).

  A connection structure between a plurality of baffle plates 71 will be described using baffle plates 71-1, 71-2, 71-3 shown in FIGS. 2 and 3 among the plurality of baffle plates 71.

  Baffle plates 71-2 and 71-3 are respectively arranged on the front and back sides (vertical direction) of the baffle plate 71-1, and are connected via connecting members 73-1 and 73-2, respectively.

  That is, the baffle plate 71-1 and the baffle plate 71-2 facing the baffle plate 71-1 on the surface side are connected to each other in the vertical direction with a predetermined interval therebetween via the connecting member 73-1. Has been.

  On the other hand, the baffle plate 71-1 and the baffle plate 71-3 facing the baffle plate 71-1 on the back surface side are, in this embodiment, a connecting member 73-located at a position away from the connecting member 73-1. 2 are connected to face each other. Here, in the predetermined baffle plate 71-1, the positions of the holes for connecting the baffle plates 71-1 and 71-2 facing each other above and below the predetermined baffle plate 71-1 are set in the circumferential direction or the radius. It is formed at a position shifted in the direction (here, the horizontal direction). As a result, the end portions of the shaft member 732 inserted through these holes are displaced in the horizontal direction, and the positions where the shaft centers do not overlap above and below the predetermined baffle plate 71, that is, they are not spaced apart from each other and do not contact each other. It is comprised so that it may be arrange | positioned in a position. With this configuration, even if the connecting member 73 is made of a metal such as stainless steel and is made of a conductive material, the baffle plates 71 connected by the connecting member 73 are predetermined in a state of being insulated from each other. They can be placed opposite each other with an interval between them.

  In the connecting member 73, the shaft member 732 installed between the baffle plates 71 is a bolt. However, the present invention is not limited to this, and the baffle plates 71 facing each other may be connected by a flexible member.

  Since these baffle plates 71 are integrated as a plurality of baffle plates 71 as a partition unit 70, the installation of the refrigerant tank 21 to the gas refrigerant layer by the gas refrigerant AN is simply inserted into the drawer tubular portion 21B. Can be done easily.

  A suspension member such as a braided wire 75 for installing the partition unit 70 (the plurality of baffle plates 71) on the gas solvent layer is attached to the upper portion of the partition unit 70. By arranging the partition unit 70 in a state where the partition unit 70 is suspended in the extraction cylindrical portion 21B via the suspension member, the plurality of baffle plates 71 are disposed at predetermined intervals in the gas refrigerant layer.

  Moreover, in this Embodiment, when installing the several baffle board 71 in the drawer | drawing-out cylindrical part 12B, the central opening part 712 of the baffle board 71 located in the lowest step among the several baffle boards 71 is made into electric field relaxation. It is configured to be loosely inserted on the outer peripheral side of the upper end portion of the portion 62 so as to have the same axial center. Thereby, for example, in assembling the terminal connection portion 1, the partition unit 70, that is, the plurality of baffle plates 71 can be easily positioned with respect to the electric field relaxation portion 62 attached to the lower end portion of the conductor lead portion 30. it can.

  Thus, by installing the partition unit 70 in the drawer tubular portion 21B of the refrigerant tank 21, the plurality of baffle plates 71 are arranged in the drawer tubular portion 21B above the refrigerant tank body 21A in the refrigerant tank 21, That is, it is installed in the gas refrigerant layer above the refrigerant liquid level NS of the liquid refrigerant N and below the normal temperature part (here, the soot tube 40). The plurality of baffle plates 71 are provided in the terminal connection portion 1 in the temperature gradient portion between the liquid refrigerant layer and the normal temperature layer in the refrigerant tank 21 between the cryogenic temperature of the liquid refrigerant and the normal temperature (for example, room temperature) of the normal temperature portion. It arrange | positions so that the temperature of may be divided in steps.

  Returning to FIG. 1, the soot tube 40 has a polymer sleeve 41 and a shielding fitting 42.

  The polymer sleeve 41 has an insulating cylinder 41a and a polymer cover 41b. The insulating cylinder 41a is made of FRP (fiber reinforced plastic) having high mechanical strength. The polymer covering 41b is made of a material having excellent electrical insulation performance, for example, a polymer material such as silicone polymer (silicone rubber). The polymer cover 41b is provided on the outer periphery of the insulating cylinder 41a, and a plurality of umbrella-shaped ridges are formed on the outer peripheral surface of the polymer cover 41b so as to be separated in the longitudinal direction. The inside of the polymer sleeve 41 (inside the insulating cylinder 41a) is hollow.

  The shielding metal fitting 42 has a cylindrical portion 42a embedded concentrically with the polymer sleeve 41, and a flange portion 42b extending radially outward from the lower end of the cylindrical portion 42a. The cylindrical portion 42a has an electric field relaxation function and relaxes the electric field of the soot tube 40.

  By placing the soot tube 40 on the upper portion of the first cylindrical portion 22B of the vacuum chamber 22 and connecting the flange portion 42b of the shielding metal fitting 42 with a connecting member (not shown) such as a bolt, the soot tube 40 is in the vacuum chamber 22. To be airtightly fixed. The inside of the soot tube 40 communicates with the first cylindrical portion 22B and is in a vacuum state during operation. Thereby, since a vacuum heat insulation part can be ensured largely, the heat penetration | invasion from the outside through the conductor extraction | drawer part 30 can be reduced.

  The shield energization unit 50 is a conductor for grounding the cable shield layer 114 of the superconducting cable 10. The shield energization unit 50 includes a shield lead bar made of, for example, a copper bar. In addition, the structure of the shield energization part 50 is not limited to this, A well-known structure is applicable. One end of the shield energization part 50 (shield lead bar) penetrates the second cylindrical part 22C of the vacuum chamber 22 in an airtight manner and is drawn to the outside, and the other end is connected to the shield connection terminal 14. The shield energization unit 50 is electrically connected to the cable shield layer 114 of the superconducting cable 10 via the shield connection terminal 14.

  The shield energization unit 50 preferably has at least a flexible conductor (not shown) such as a flat knitted copper wire. Thereby, even if the position of the shield connection terminal 14 moves in the horizontal direction (left and right direction in FIG. 1) due to thermal expansion and contraction of the superconducting cable 10, it can be easily followed, and thus damage to the lid 63 and the like can be prevented. .

  As described above, the terminal connection portion 1 stores the terminal portion of the superconducting cable 10 and the liquid refrigerant N that cools the terminal portion of the superconducting cable 10, and the liquid refrigerant layer and the gas refrigerant in which the terminal portion of the superconducting cable 10 is disposed. The refrigerant tank 21 in which the layers are formed, the lower end portion is immersed in the liquid refrigerant N, and is connected to the superconducting conductor layer (conductor) 112 of the superconducting cable 10, and the upper end side passes through the gas refrigerant layer and the soot pipe (room temperature portion) And a conductor lead-out portion 30 led out to 40. The gas refrigerant layer of the refrigerant tank 21 is provided with a plurality of baffle plates 71 that are arranged around the conductor lead-out portion 30 and partition the gas refrigerant layer with a predetermined interval in the extending direction of the conductor lead-out portion 30. . The soot tube 40 constitutes a normal temperature part and is airtightly fixed to the refrigerant tank 21. The conductor lead-out portion 30 is inserted into the soot tube 40, and the upper end portion of the conductor lead-out portion 30 is exposed to the outside of the soot tube 40. Further, the plurality of baffle plates 71 may each be made of fiber reinforced plastic.

  The plurality of baffle plates 71 are a first baffle plate 71-1, a second baffle plate 71-2 facing the front surface side thereof, and a third baffle plate 71-1 facing the back surface side of the first baffle plate 71-1. Baffle plate 71-3. The first baffle plate 71-1 and the second baffle plate 71-2 are connected via a first connecting member 73-1 installed between the first and second baffle plates 71-1 and 71-2. Are connected with a predetermined interval. The first baffle plate 71-1 and the third baffle plate 71-3 are connected via a second connecting member 73-2 installed between the first and third baffle plates 71-1 and 71-3. Are connected with a predetermined interval. The 1st connection member 73-1 and the 2nd connection member 73-2 are arrange | positioned in the position spaced apart in the 1st baffle board 71-1. That is, in the plurality of baffle plates 71, the baffle plates (for example, baffle plates 71-1 and 71-2, 71-1 and 71-3) facing each other in the extending direction of the conductor lead-out portion 30 are between the baffle plates. They are connected to each other with a predetermined interval through connecting members 73 that are installed. And when connecting member 73-1 and 73-2 are each protrudingly provided by the front and back side for every baffle board (baffle board 71-1 as an example), connecting member 73-1 and 73-2 are the said baffle. It arrange | positions in the position spaced apart in a board (a baffle board 71-1 as an example). In addition, an electric field relaxation portion 62 having an upper end located above the position of the liquid surface NS of the liquid refrigerant N is attached to the outer periphery on the lower end side of the conductor extraction portion 30, is a gas refrigerant layer, and the conductor extraction portion 30. The plurality of baffle plates 71 arranged around the upper end of the baffle plate 71 are positioned by engaging the inner periphery of the lowermost baffle plate 71 with the outer periphery of the upper end portion of the electric field relaxation unit 62.

  According to the terminal connection portion 1, in the refrigerant tank 21 in which the liquid refrigerant layer by the liquid refrigerant N and the gas refrigerant layer by the gas refrigerant AN are formed, the gas refrigerant layer between the normal temperature room temperature layer and the cryogenic liquid refrigerant layer. Then, the baffle plate 71 ensures heat insulation for each of the upper and lower layers of the baffle plate 71.

  Accordingly, the plurality of baffle plates 71 reduce the convection of the gaseous refrigerant (nitrogen) between the upper and lower sides of each baffle plate 71 in the gas refrigerant layer, so that the temperature gradient in the gas refrigerant layer is stepped between the baffle plates 71. This makes it easy to create a temperature distribution in the conductor lead-out portion 30. In this manner, the gas refrigerant layer is partitioned by a plurality of layers at a predetermined interval by the plurality of baffle plates 71 arranged around the conductor extraction portion 30 in the gas refrigerant layer of the refrigerant tank 21. Therefore, it is possible to suitably reduce the heat intrusion from the outside to the inside through the conductor lead-out portion 30, that is, the heat intrusion from the normal temperature portion side to the cryogenic liquid refrigerant layer side, thereby terminating the highly reliable superconducting cable 10. Part 1 can be realized.

  Further, in the terminal connection portion 1, a gap S <b> 1 is formed between the baffle plate 71, the inner peripheral surface of the extraction cylindrical portion 21 </ b> B in which a gas refrigerant layer is formed, and the outer edge of the baffle plate 71. A gap S <b> 2 is formed between the conductor lead-out portion 30 disposed inside the plate 71. That is, a plurality of baffle plates 71 are loosely inserted into a drawer tubular portion 21B in which a gas refrigerant layer is formed by containing the gas refrigerant AN therein (filled with the gas refrigerant AN). The conductor lead-out part 30 is loosely inserted in the inside. Thereby, the thermal contraction during operation of the refrigerant tank 21 (particularly, the extraction tubular portion 21B), the thermal contraction during operation of the superconducting cable 10, or the conductor extraction portion 30 accompanying the thermal contraction during operation of the superconducting cable 10 is achieved. Even if the displacement occurs, each component does not collide with the baffle plate 71. In addition, the gas refrigerant AN itself (nitrogen) itself can move in the vertical direction without causing heat intrusion due to the gaps S1 and S2.

  In addition, in the plurality of baffle plates 71, when the baffle plates 71-2 and 71-3 are opposed to a predetermined baffle plate (baffle plate 71-1) on the front and back surfaces, the respective baffle plates 71-2, Since the connecting members 73-1 and 73-2 that connect 71-3 are arranged at positions that are separated from each other on the predetermined baffle plate 71-1, the connecting members 73-1 and 73-2 are conductive metals or the like. Even if it is formed of the above material, it can be insulated for each baffle plate 71.

  In addition, in the termination | terminus connection part 1 of embodiment, although several baffle plates 71 were set as the structure connected with the connection member 73, the insulation part which insulates the baffle plates 71 which connect the connection member 73 is included. It is good also as a structure. In other words, the plurality of baffle plates 71 may be connected to each other with a predetermined interval by a connecting member formed of an insulating material. According to this configuration, there is no need to insulate the baffle plates 71. In the above configuration, for example, if the shaft member 732 is formed of an insulating material, a connecting member that connects the baffle plates 71 facing each other (for example, The connecting members 73-1 and 73-2) 73 can all be arranged at coaxial positions, or the connecting members (73-1 and 73-2) can be arranged at adjacent positions.

  FIG. 4 is a perspective view showing another example of the partition unit used for explaining the baffle plate of the terminal connection portion 1 according to the embodiment of the present invention.

  The partition unit 700 shown in FIG. 4 differs from the partition unit 70 only in that the connecting member is replaced with the connecting member 730, and the other components are the same. Therefore, the same components as those of the partition unit 70 are denoted by the same reference numerals and description thereof is omitted.

  A partition unit 700 shown in FIG. 4 is arranged around the conductor lead-out portion 30 in the gas refrigerant layer of the refrigerant tank 21 in the terminal connection portion 1 of FIG. 1, and the gas refrigerant layer is predetermined in the extending direction of the conductor lead-out portion 30. A plurality of baffle plates 71 having a plurality of insulating properties are provided to partition at intervals.

  The plurality of baffle plates 71 are connected to each other at a predetermined interval by a rod-like material 72 that is an insulating material.

  The rod-shaped member 72 is inserted through the plurality of baffle plates 71 and fixed to each of the plurality of baffle plates 71 at a predetermined interval. Here, the rod member 72 is a rod member made of FRP, and together with a fastening member 734 for fastening the rod member 72 to each baffle plate 71, a connecting member 730 that inserts and connects each of the plurality of baffle plates 71. Configure. Note that the nut as the fastening member 734 may be made of metal as long as the rod-shaped member 72 is made of an insulating material.

  The rod-shaped member 72 may be fixed to the baffle plate 71 using an adhesive or the like in any case, but here, the baffle plate 71 has a male screw at a portion sandwiching a portion inserted through a hole passing through the front and back surfaces. This is fixed to the baffle plate 71 by screwing and fastening a nut as a fastening member 734 to the male screw portion from the front and back sides of the baffle plate 71.

  That is, the rod-shaped member 72 has a length through which all of the plurality of baffle plates 71 are inserted, and a male screw portion formed at a predetermined interval on the outer periphery corresponding to a portion where the baffle plate 71 is fixed. Is provided.

  When the partition unit 700 is arranged in the gas refrigerant layer, the plurality of baffle plates 71 arranged around the conductor lead-out portion 30 have the inner diameter of the lowermost baffle plate 71 as the upper end of the electric field relaxation portion 62. Positioned by engaging the outer diameter of the part.

  According to the partition unit 700, it is possible to obtain the same effects as the plurality of baffle plates 71 included in the partition unit 70, and to easily connect the baffle plates 71 without considering each other's insulation treatment. be able to.

  In FIG. 4, a plurality of baffle plates 71 are connected via one bar-like member 72 of the connecting member 730. However, the present invention is not limited to this, and a plurality of baffle plates 71 are connected using a similarly configured connecting member 730-1. It is good also as a structure connected with the rod-shaped material 72 of a book. Moreover, it is good also as a structure which replaces with the rod-shaped material 72 in the partition unit 700, and connects the several baffle board 71 at predetermined intervals by one flexible insulating material.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Termination connection 10 Superconducting cable (Cryogenic cable)
DESCRIPTION OF SYMBOLS 11 Cable core 13 Electrode part 20 Cryogenic container 21 Refrigerant tank 21A Refrigerant tank main body 21B Draw-out cylindrical part 21C Shield outlet 22 Vacuum tank 22A Vacuum tank main body 22B 1st cylindrical part 22C 2nd cylindrical part 30 Conductor extraction Part 40 Steel pipe 41 Polymer sleeve 41a Insulating tube 41b Polymer cover 42 Shielding metal fitting 42a Cylindrical part 42b Flange part 50 Shield energization part 62 Electric field relaxation part 70, 700 Partition unit 71 Baffle plate 72 Rod-shaped material 73, 730 Connecting member 75 Braided wire 111 Former 112 Superconducting conductor layer 113 Electrical insulating layer 114 Cable shield layer 115 Protective layer 121 Thermal insulation inner tube 122 Thermal insulation outer tube 212, 222 Rear end portion 712 Opening portion 732 Shaft member 734 Fastening member S1, S2 Gap

Claims (5)

The end of the cryogenic cable,
A refrigerant tank in which liquid refrigerant for cooling a terminal portion of the cryogenic cable is stored, and a liquid refrigerant layer in which the terminal portion of the cryogenic cable is disposed and a gas refrigerant layer continuous on the liquid refrigerant layer; ,
A conductor lead-out portion whose lower end is immersed in the liquid refrigerant and connected to the conductor of the cryogenic cable, and whose upper end is drawn out to the room temperature portion through the gas refrigerant layer;
Have
The gas refrigerant layer of the refrigerant tank is disposed around the conductor extraction portion, and has a plurality of insulating baffle plates that divide the gas refrigerant layer at predetermined intervals in the extending direction of the conductor extraction portion. Is provided,
Cryogenic cable termination connection. The normal temperature part has a soot tube that is airtightly fixed to the refrigerant tank,
The conductor lead portion is inserted into the soot tube, and an upper end portion of the conductor lead portion is exposed to the outside of the soot tube.
The termination | terminus connection part of the cryogenic cable of Claim 1. The plurality of baffle plates include a first baffle plate, a second baffle plate facing the front surface side thereof, and a third baffle plate facing the back surface side of the first baffle plate,
The first baffle plate and the second baffle plate are connected to each other at a predetermined interval via a first connecting member provided between the first and second baffle plates.
The first baffle plate and the third baffle plate are connected to each other at a predetermined interval via a second connecting member provided between the first and third baffle plates.
The first connecting member and the second connecting member are disposed at positions separated from each other in the first baffle plate.
The termination | terminus connection part of the cryogenic cable of Claim 1 or 2. The plurality of baffle plates are connected via a connecting member that passes through each of the baffle plates,
The connecting member has an insulating property and has a length for inserting a plurality of baffle plates;
The termination | terminus connection part of the cryogenic cable of Claim 1 or 2. The plurality of baffle plates are each made of fiber reinforced plastic,
The termination | terminus connection part of the cryogenic cable as described in any one of Claim 1 to 4.

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