JP2018078720A - Terminal connector of cryogenic cable - Google Patents

Abstract

An end connection portion of a cryogenic cable having stable superconducting characteristics while cooling a superconducting cable and maintaining a low temperature state even when a refrigerant is introduced. A terminal part of a cryogenic cable, a conductor connected to a conductor of the terminal part of the cryogenic cable, and an electrode part for extracting current to the outside, and a terminal part and an electrode part of the cryogenic cable are accommodated during operation. A refrigerant tank into which the refrigerant is introduced, a vacuum tank that houses the refrigerant tank and is in a vacuum state during operation, is provided to project from the refrigerant tank in the axial direction of the refrigerant tank, and the end of the cryogenic cable is connected to the refrigerant tank The cable holding member is held at the center position, and the cable holding member is provided with a baffle plate between the introduction portion into which the refrigerant is introduced and the electrode portion. [Selection] 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 is composed of a closed-bottomed cylindrical refrigerant tank that contains the terminal portion of the superconducting cable and is filled with a refrigerant such as liquid nitrogen during operation, and a vacuum tank that contains the refrigerant tank and is in a vacuum state during operation. (For example, patent documents 1 and 2). The heat insulation inner pipe of the superconducting cable is connected to the refrigerant tank, and the heat insulation outer pipe is connected to the vacuum tank. The refrigerant tank is installed in the vacuum tank by an appropriate method (for example, suspended in a vacuum container in Patent Document 2).

The cable core as the terminal part of the superconducting cable accommodated in the refrigerant tank has a high voltage during the operation of the terminal connection part, so that the distance from the outer peripheral surface of the refrigerant tank functioning as ground is as constant as possible. It is located on the axis of the refrigerant tank, that is, at the center position of the refrigerant tank. For example, in Patent Document 3, the former drawn from the tip of the cable core in the refrigerant tank is insulated on the end face of the refrigerant tank opposite to the end face into which the cable core is inserted (the face facing the tip face of the cable core). By fixing through the cable core, the cable core is positioned on the axis of the refrigerant tank and fixed.
Further, a circulation pump is generally connected to the terminal connection portion of the superconducting cable in order to circulate the refrigerant filled in the heat insulating inner pipe. The circulation pump is connected to each of the terminal connection portions provided at both ends of the superconducting cable.
In the superconducting cable system using the superconducting cable end connection, the refrigerant is supplied from one end connection at both ends of the superconducting cable via the circulation pump, and from the other end connection through the insulated inner pipe of the superconducting cable. It is configured to circulate back to the circulation pump. As a result, the inside of the heat insulating inner tube is maintained at a low temperature, the heat penetration is prevented, and the conductive performance of the superconducting cable is maintained.

Japanese Patent No. 4778452 Japanese Patent No. 4096360 JP 2012-120435 A

At the terminal connection part of the superconducting cable described above, once the refrigerant is started to circulate by the circulation pump, continuous operation is performed for a long time. However, the operation of the circulation pump is performed within a short time in a test or maintenance for confirming the performance. May be turned on and off.
When the circulating pump is started or stopped by these on / off operations, especially the pressure fluctuation generated when starting the circulating pump propagates to the liquid nitrogen, which is the refrigerant in the heat-insulated inner pipe, through the introduction section and fluctuates, and the interface of liquid nitrogen As the liquid nitrogen in the electric field relaxation part fluctuates, heat from the outside enters and the temperature rises at the interface of the liquid nitrogen and the electric field relaxation part. If the temperature rises due to this temperature rise and heat is frequently generated, there is a risk of damage to parts in the portion where the temperature has risen.

  An object of the present invention is to provide a termination connection portion of a cryogenic cable having stable superconducting characteristics while cooling the superconducting cable and maintaining a low temperature state even when a refrigerant is introduced.

The terminal connection part of the cryogenic cable according to the present invention is:
The end of the cryogenic cable,
An electrode part connected to the conductor of the terminal part of the cryogenic cable, and for drawing an electric current to the outside;
A refrigerant tank that accommodates the terminal part of the cryogenic cable and the electrode part, and into which refrigerant is introduced during operation,
A vacuum chamber that houses the refrigerant tank and is in a vacuum state during operation;
A cable holding member that protrudes from the refrigerant tank in the axial direction of the refrigerant tank and holds a terminal portion of the cryogenic cable at a central position of the refrigerant tank;
Have
The cable holding member has a configuration in which a baffle plate is provided between the introduction portion into which the refrigerant is introduced and the electrode portion.

  ADVANTAGE OF THE INVENTION According to this invention, the termination | terminus connection part of the superconducting cable which has the stable superconducting characteristic is realizable, cooling a superconducting cable even at the time of introduction | transduction of a refrigerant | coolant, and maintaining a low-temperature state.

It is a figure which shows the termination | terminus connection part which concerns on one embodiment of this invention. It is the figure which looked at the baffle plate from the front end side. It is sectional drawing of the AA arrow line part of FIG. It is a figure which shows the modification of the termination | terminus connection part of the superconducting cable which concerns on one embodiment of this invention. It is a figure which shows the fluctuation | variation of the behavior of the refrigerant | coolant which is due to the pressure fluctuation generate | occur | produced by starting of a circulation pump.

  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 on which the 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 cryogenic cable 10, a cryogenic container 20, a conductor lead-out portion 30, a shield energizing portion 40, a soot tube 50, a cable holding member 80, a baffle plate 200, and the like. The terminal portion of the cryogenic cable 10 is accommodated in a predetermined state in the cryogenic container 20 (specifically, the refrigerant tank 21), and the conductor current of the cryogenic cable 10 is transferred to the actual system side such as a power device via the conductor lead-out portion 30. Pulled out.

  The cryogenic cable 10 is a single-core superconducting cable in which a single cable core 11 is accommodated in a heat insulating tube 12. Note that the cryogenic cable 10 may be a three-core 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 cryogenic cable 10, the cable core 11 is stepped and the layers are exposed in order from the tip side. On the outer periphery of the superconducting conductor layer 112, an electrode portion 13 such as a conductor connection terminal that is electrically connected to the superconducting conductor layer 112 is disposed. In the refrigerant tank 21, the propagation of the linear pressure to the electrode unit 13 when the refrigerant (for example, liquid nitrogen) N supplied from the introduction unit 92 circulates between the introduction unit and the electrode unit 13 is inhibited. A baffle plate 200 serving as a barrier is arranged. 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 layer 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 the refrigerant N 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 a hollow bottomed cylindrical shape, for example, and includes a refrigerant tank main body 21 </ b> A that accommodates the terminal portion of the cryogenic cable 10, and a conductor lead-out cylindrical part connected to a conductor outlet that introduces the conductor lead-out part 30. 21C and the shield outlet 21B which introduces the shield energization part 40 are provided. Note that the refrigerant tank body 21A may not have a bottomed cylindrical shape integrally formed. 21 A of refrigerant tank main bodies of this Embodiment are formed by obstruct | occluding the front end side opening of a cylindrical part with the disk-shaped front-end | tip part 211. FIG. For example, the refrigerant tank 21 may be hung from the vacuum tank 22 or may be placed on a pedestal (not shown) disposed in the vacuum tank 22.

  The end of the cryogenic 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). The rear end side of the refrigerant tank 21 is hermetically sealed with the rear end portion 212 so that the refrigerant N in the refrigerant tank 21 does not leak outside the refrigerant tank 21. The heat insulating inner tube 121 of the cryogenic cable 10 is airtightly connected to the central portion of the rear end portion 212.

  A circulation pump 9 as a refrigerant circulation device is connected to the refrigerant tank 21. In the refrigerant tank 21, an introduction portion 92 that constitutes an opening portion on one end side of the supply pipe 90 connected to the circulation pump 9 is disposed on the distal end side. The introduction part 92 opens into the refrigerant tank 21 from above the refrigerant tank 21.

In addition, the terminal connection part on the opposite side to the terminal part of the cryogenic cable 10 shown in FIG. 1 is provided with the termination | terminus connection part of the structure similar to the termination | terminus connection part 1 of this Embodiment, for example. The terminal connection portion is provided with a lead-out portion (the introduction portion 92 of the present embodiment may be used) that communicates with the refrigerant tank and leads the refrigerant N to the outside. This derivation unit is connected to the circulation pump 9. The circulation pump 9 introduces the refrigerant N into the refrigerant tank 21 through the introduction part 92 during operation, passes through the heat insulating inner pipe 121 of the cryogenic cable 10, and leads from the terminal connection part on the opposite side of the cryogenic cable 10. Then, the refrigerant is pumped up through the refrigerant and introduced into the refrigerant tank 21 through the introduction part 92 again. By repeating this, the refrigerant N is circulated and supplied from the circulation pump 9 in the terminal connection portion 1 of the cryogenic cable 10.
The heat insulating inner pipe 121 communicating with the refrigerant tank 21 is also filled with the refrigerant N. The front end side of the refrigerant tank 21 is hermetically sealed by a plate-shaped front end portion 211 so that the refrigerant N in the refrigerant tank 21 does not leak out of the refrigerant tank 21.

  In the refrigerant tank 21, the supplied liquid refrigerant N is stored, and the terminal portion of the cryogenic cable 10 is cooled by the refrigerant N. In the refrigerant tank 21, a liquid refrigerant layer made of a liquid refrigerant (for example, liquid nitrogen) is formed below the interface (here, the liquid level) NS of the refrigerant N, and a gas refrigerant (for example, gaseous nitrogen) is formed above the liquid level NS. A gas refrigerant layer made of AN 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> C of the refrigerant tank 21. The drawer cylindrical portion 21 </ b> C 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 in communication with each other. An upper pipe 50 called a normal temperature part is generally fixed to the upper part of the drawer cylindrical part 21C in a state where the insides are in communication with each other. A partition unit 70 having a plurality of baffle plates 71 that communicate with each other while partitioning the gas coolant layer into a plurality of layers is disposed in the gas coolant layer in the drawer tubular portion 21C.
The refrigerant tank 21 has a rod attachment hole 2111 (see FIG. 3) for fixing a rod portion 82 to be described later at the tip end portion 211. In addition, the refrigerant tank 21 has a bottomed and covered cylindrical shape in which a shaft is horizontally disposed by having a front end portion 211 and a rear end portion 212.

  Further, the tip end 211 of the refrigerant tank 21 protrudes in the axial direction (extending direction of the cryogenic cable 10) inside the refrigerant tank 21, and holds the terminal portion of the cryogenic cable 10 at a predetermined position. A member 80 is provided. The predetermined position is a central axis along the extending direction (here, the horizontal direction) of the cryogenic cable 10 in the refrigerant tank 21, that is, the center position of the refrigerant tank 21. A specific holding structure of the terminal portion of the cryogenic cable 10 by the cable holding member 80 will be described later.

  The vacuum chamber 22 has, for example, a cylindrical shape, and includes a vacuum chamber main body 22A that houses the refrigerant tank 21, a first cylindrical portion 22B that is suspended upward from the vacuum tank main body 22A, and a first It has the 2nd cylindrical part 22C which is spaced apart from the cylindrical part 22B, and hangs upwards from the vacuum tank main-body part 22A. In general, the first cylindrical portion 22B and the second cylindrical portion 22C are called temperature gradient portions. The front end side of the vacuum chamber 22, that is, the front end side of the vacuum chamber body 22A and the rear end side of the vacuum chamber 22, that is, the rear end side of the vacuum chamber body 22A, ensure the vacuum chamber 22 in a vacuum state. In order to achieve this, the plate-like front end 221 and rear end 222 are hermetically sealed. The vacuum chamber main body 22A has a front end 221 and a rear end 222 so that it has a cylindrical shape with a bottom and a lid with the shaft arranged horizontally.

  In the vacuum chamber 22, the drawer cylindrical part 21C is positioned in the first cylindrical part 22B, and the shield outlet 21B is positioned below the second cylindrical part 22C. The refrigerant tank 21 is arranged. A heat insulating outer tube 122 of the cryogenic 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 21C, and a soot tube 50 that is airtightly communicated with the inside of the drawer tubular portion 21C is fixed to the upper portion of the first tubular portion 22B. Is done.
The conductor lead-out portion 30 is disposed on the first tubular portion 22B, and the soot tube 50 is disposed on the upper portion of the first tubular portion 22B. In the second cylindrical portion 22C, a measurement pipe 61 for introducing sensors of various instruments (for example, a liquid level gauge, a thermometer, a pressure gauge, etc.) and a shield energizing section 40 are arranged in the refrigerant tank 21. The

  Since the shield outlet 21B in the refrigerant tank 21 is accommodated in the vacuum tank main body 22A of the vacuum tank 22, the shield energization part 40 and the measurement pipe 61 serving as a heat transfer path are introduced to the inside of the vacuum tank main body 22A. The In order to reduce heat intrusion, it is necessary to secure the heat transfer path length. However, the temperature of the refrigerant tank main body 21A and the shield outlet 21B of the refrigerant tank 21 is accommodated in the vacuum tank main body portion 22A of the vacuum tank 22. Since it becomes easy to ensure the heat transfer path length by the gradient part, the height of the first cylindrical part 22B and the second cylindrical part 22C can be kept low. Therefore, it is possible to reduce the size of the terminal connection portion 1.

  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 and the inside of the soot tube 50 are also maintained in a vacuum state.

  The conductor lead-out part 30 is a conductor for drawing a current from the cryogenic 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-out portion 30 (conductor lead-out rod) passes through the soot tube 50 in an airtight manner and is drawn to the outside, and the other end is connected to the electrode portion 13. The conductor lead portion 30 is electrically connected to the superconducting conductor layer 112 of the cryogenic cable 10 via the electrode portion 13.

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

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

  Moreover, the upper end part of the conductor lead-out part 30 passes through the inside of the soot pipe 50, penetrates the top end part of the soot pipe 50 in an airtight manner, and is exposed to the outside of the soot pipe 50 so as to be electrically connectable.

  Further, at the lower end portion of the conductor lead-out portion 30, an electric field relaxation portion (so-called stress cone) 32 is arranged on the outer periphery of the upper portion of the portion of the conductor lead-out portion 30 that is connected to the electrode portion 13 (lower end of the conductor lead-out portion 30). It is installed. The electric field relaxation part 32 has a cylindrical shape that relaxes the electric field of the current drawn from the electrode part 13 and flowing through the conductor lead part 30. The electric field relaxation unit 32 is provided in the refrigerant tank 21 in the vicinity of the electrode unit 13 and around the conductor lead-out unit 30 to relieve the electric field generated at the connection portion between the cryogenic cable 10 and the electrode unit 13. In the present embodiment, electric field relaxation unit 32 is disposed below the liquid level of liquid refrigerant N. The outer diameter of the electric field relaxation part 32 is smaller than the inner diameter of the lead cylindrical part 21C, and is formed so that a gap is formed between the inner peripheral surface of the lead cylindrical part 21C.

  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 21 </ b> C of the refrigerant tank 21.

  The baffle plate 71 is provided with a partition unit 70 in the gas refrigerant layer in the refrigerant tank 21, so that the plurality of baffle plates 71 are arranged around the conductor extraction part 30 in the extraction cylindrical part 21 </ b> C of the refrigerant tank 21. The conductor lead-out portion 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. 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). Therefore, it arrange | positions so that it may partition with the predetermined space | interval which is the space | interval for every temperature range corresponding to a temperature gradient. Thereby, the baffle plate 71 forms a plurality of layers in which the gas can go back and forth in the drawer tubular portion 21C. Specifically, the predetermined interval that is the installation position of the baffle plate 71 is a temperature based on the length of the vacuum chamber 22 along the conductor extraction portion 30 (the length of the cylindrical portion 22B of the outer peripheral portion of the extraction cylindrical portion 21C). Set by gradient. If the length of the vacuum chamber 22 is long, the temperature gradient in the extending direction of the conductor lead-out portion 30 (gradient of temperature decrease from the normal temperature at the upper end to the cryogenic temperature at the lower end) becomes smaller, and the temperature range corresponding to the gradient The baffle plate 71 is disposed so as to be partitioned by The plurality of baffle plates 71 are connected to each other with a predetermined interval through a connecting member. The baffle plate 71 is an annular flat plate made of plastic or other insulator corresponding to the inner peripheral shape of the drawer tubular portion 21C, and has heat insulation. 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).

  The shield energization unit 40 is a conductive member for grounding the cable shield layer 114 of the cryogenic cable 10. The configuration of the shield energization unit 40 is substantially the same as the configuration of the conductor extraction unit 30. That is, the shield energization unit 40 includes a shield lead bar made of, for example, a copper bar or a pipe. In addition, the structure of the shield energization part 40 is not limited to this, A well-known structure is applicable. One end of the shield energization part 40 (shield lead bar) is hermetically penetrated through the second cylindrical part 22C of the vacuum chamber 22 and drawn to the outside, and the other end is connected to the shield connection terminal 14. The shield energization unit 40 is electrically connected to the cable shield layer 114 of the cryogenic cable 10 via the shield connection terminal 14.

  The shield energizing section 40 preferably has a flexible conductor (not shown) such as a flat knitted copper wire at least partially. 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 the thermal contraction of the cryogenic cable 10, it can easily follow, thus preventing damage to the lid 63 and the like. it can.

  The soot tube 50 has a polymer sleeve 51 and a shielding fitting 52.

  The polymer sleeve 51 includes an insulating cylinder 51a and a polymer cover 51b. The insulating cylinder 51a is made of FRP (fiber reinforced plastic) having high mechanical strength. The polymer covering 51b is made of a material having excellent electrical insulation performance, for example, a polymer material such as silicone polymer (silicone rubber). The polymer cover 51b is provided on the outer periphery of the insulating cylinder 51a, and a plurality of umbrella-shaped ridges are formed on the outer peripheral surface of the polymer cover 51b so as to be separated in the longitudinal direction. The inside of the polymer sleeve 51 (inside the insulating cylinder 51a) is hollow.

  The shielding metal fitting 52 has a cylindrical portion 52a embedded concentrically with the polymer sleeve 51, and a flange portion 52b extending radially outward from the lower end of the cylindrical portion 52a. The cylindrical portion 52a has an electric field relaxation function, and relaxes the electric field of the soot tube 50.

  By placing the soot tube 50 on the upper portion of the first cylindrical portion 22B of the vacuum chamber 22 and connecting the flange portion 52b of the shielding metal fitting 52 with a connecting member (not shown) such as a bolt, the soot tube 50 is in the vacuum chamber 22. To be airtightly fixed. The inside of the soot tube 50 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 baffle plate 200 prevents the refrigerant N in the vicinity of the electrode part 13 from being fluctuated by the refrigerant N introduced from the introduction part 92. When the baffle plate 200 circulates the refrigerant N introduced from the introduction part 92 and filled in the refrigerant tank 21, the baffle plate 200 linearly changes the pressure fluctuation generated by the circulation pump activation from the introduction part 92 to the electrode part 13. Inhibits propagation to When pressure linearly propagates from the introduction part 92 to the electrode part 13, the refrigerant N in the vicinity of the electrode part 13 may fluctuate, affecting surrounding parts including the electrode part 13, and possibly causing problems such as impulse destruction. Because there is.
The baffle plate 200 is provided on the cable holding member 80 (specifically, the rod portion 82) so as to be positioned between the introduction portion 92 into which the refrigerant N is introduced and the electrode portion 13. The baffle plate 200 has an insulating property and is formed of, for example, fiber reinforced plastics (FRP).

The baffle plate 200 is disposed between the introduction portion 92 and the electrode portion 13 on the front end side in the refrigerant tank 21, and particularly in the lower portion of the introduction portion 92 and the surrounding conductor leading cylindrical portion 21 </ b> C of the electrode portion 13. Between the vicinity of the interface X of the refrigerant N and the vicinity Y of the electric field relaxation part 32 including the periphery of the electric field relaxation part 32.
As shown in FIG. 2, the baffle plate 200 includes a plate body portion 210 having an area substantially equal to the inner area of the refrigerant tank 21, and a notch portion 220 is formed in a part of the plate body portion 210. The shape of the notch 220 is such as any polygon, circular through-hole, polygonal notch, etc., in which a part of the plate body 210 is notched and the front and back sides of the plate body 210 are communicated. Any method may be used.

The baffle plate 200 has an outer diameter substantially equal to the inner area of the refrigerant tank 21, that is, the cross-sectional area surrounded by the inner diameter, and the outer edge is close to the inner peripheral surface of the refrigerant tank 21 and has a slidable shape. ing. That is, the baffle plate 200 installed in the refrigerant tank 21 is in a state where there is substantially no gap between the outer edge excluding the notch portion 220 and the inner peripheral surface of the refrigerant tank 21. Further, since the peripheral wall of the refrigerant tank 21 and the baffle plate 200 are separate members, it is difficult for heat to be transmitted to the baffle plate 200 via the refrigerant tank 21.
The notch 220 is formed to open on the front and back surfaces of the plate main body 210 of the baffle plate 200, and in the refrigerant tank 21, the refrigerant N passes through the notch 220 and is proximal to the leading end 92 side. Move to the side. That is, the pressure propagating to the refrigerant N passes through a path formed by being partitioned by the baffle plate 200 (transmits the refrigerant N in the path).

In the terminal connection portion 1 of the cryogenic cable 10 according to the present embodiment, a plurality of baffle plates 200 are arranged in the refrigerant tank 21, and the respective cut-out portions 220 of the plurality of baffle plates 200 are arranged on the lower side far from the electrode portion 13. Are arranged in the axial direction. The plurality of baffle plates 200 are integrally configured via spacers 242 to 244 and are easily mounted in the refrigerant tank 21.
The plate body portion 210 of the baffle plate 200 is provided with a through hole 230 through which the rod portion 82 is inserted. The rod portion 82 is inserted into the through-hole 230, is provided in a state of being suspended from the inserted rod portion 82, and is disposed between the introduction portion 92 and the electrode portion 13. The spacers 242 to 244 provided so as to sandwich the baffle plate 200 are formed with through holes that are continuous with the through holes 230. The rod portion 82 inserts the through holes of the spacers 242 to 244 together with the through hole 230 of the baffle plate 200 and supports the baffle plate 200 together with the spacers 242 to 244.

  Next, the cable holding member 80 to which the baffle plate 200 and the terminal portion of the cryogenic cable 10 are attached will be described together with the attachment structure of the baffle plate 200 and the terminal portion of the cryogenic cable 10.

  FIG. 3 is a partial cross-sectional view taken along line AA in FIG.

  As shown in FIG. 3, the end portion of the cryogenic cable 10 accommodated in the refrigerant tank 21 is positioned at the center position of the refrigerant tank 21 in the refrigerant tank 21 via the cable holding member 80, while being cryogenic. The cable 10 is held movably in the extending direction (corresponding to the axial direction of the refrigerant tank 21).

The cable holding member 80 holds the end portion of the cryogenic cable 10 and holds the baffle plate 200 provided on the cable holding member 80.
The cable holding member 80 includes a rod portion 82 and a metal fitting 83 (specifically, a metal flange portion 84).

  Here, the rod portion 82 is made of fiber reinforced plastics (FRP) having a lower thermal conductivity than metal as an insulating material. Thereby, the heat penetration | invasion from the outside can be prevented effectively. The rod portion 82 may be made of a rod-shaped material or a prismatic material.

  One end 82 a of the rod portion 82 is fixed to the front end portion 211 of the refrigerant tank 21 via a fastening portion (bolt-nut joint) 85. The rod portion 82 is provided in the refrigerant tank 21 so as to protrude in the horizontal direction (specifically, the longitudinal direction of the cryogenic cable 10 or the longitudinal direction of the refrigerant tank 21) from the distal end portion 211. A plurality of rod portions 82 may be arranged at positions rotated at a predetermined angle on a concentric circumference as viewed from the front end side or the rear end side of the end connection portion 1. That is, the plurality of rod portions 82 may be arranged on the inner side surface of the circular tip portion 211 outside the projected portion of the opposing cryogenic cable 10 and spaced apart at equal intervals in the circumferential direction. In the present embodiment, the two rod portions 82 (82A, 82B) that are horizontally separated from the inner surface of the tip end portion 211 are provided. However, the present invention is not limited to this, and a configuration that includes one rod portion 82 is provided. Alternatively, a configuration in which three, four, five or more rod portions 82 are provided on the front end portion 211 of the refrigerant tank 21 at equal intervals on a concentric circle may be adopted. Moreover, it is good also as a structure which provided the one rod part 82. FIG.

  One end portion 82 a of the rod portion 82 (82 </ b> A, 82 </ b> B) is inserted into the rod attachment hole 2111 and fixed to the distal end portion 211 by the fastening portion 85. The fixing portion 85 is fixed to the outside of the tip end portion 211 via the rod mounting hole 2111, that is, a portion of the one end portion 82 a protruding to the outside of the refrigerant tank 21 using a nut screwed from the outside. Consists of. Note that the fastening portion 85 may be configured by a nut that fastens the one end portion 82a inserted into the rod attachment hole 2111 from both sides with the tip end portion 211 interposed therebetween. Here, the rod portion 82 has a male screw portion formed at a portion corresponding to the nut at one end portion 82a, and the male screw portion and the nut as the fastening portion 85 are screwed together. Thereby, the rod part 82 is fixed to the tip part 211.

  The rod portion 82 is inserted through the rod insertion hole 86 of the metal fitting 83 attached to the cryogenic cable 10 and the through hole 230 of the baffle plate 200.

In the terminal connection portion 1, the cryogenic cable 10 is held by the cable holding member 80 via a metal fitting 83 attached to the outer periphery of the cryogenic cable 10.
In the present embodiment, the metal fitting 83 has a flat metal flange portion 84 having a central hole into which the terminal portion of the cryogenic cable 10 is inserted at the center, and a rod insertion hole 86. The metal flange portion 84 is disposed so as to protrude in the radial direction from the outer periphery of the cable core 11 of the cryogenic cable 10, and the rod insertion hole 86 is formed at a position on the outer peripheral side from the central hole. Is inserted.
The metal flange portion 84 holds the end portion of the cryogenic cable 10 in the refrigerant tank 21 by inserting the rod portion 82 into the rod insertion hole 86.

  The rod portion 82 is inserted through the through hole 230 and the rod insertion hole 86 on both sides in the horizontal direction with respect to the cryogenic cable 10.

  As a result, the components inside the refrigerant tank 21, here, the baffle plate 200 and the cryogenic cable 10 have the same axis as the axis of the refrigerant tank 21 in the refrigerant tank 21 via the rod portion 82. The refrigerant tank 21 is cantilevered so as to be an axial center. At this time, the cryogenic cable 10 (specifically, the cable core 11) is in a state of being held suspended and movably in the extending direction of the cryogenic cable 10.

In this way, the terminal connection portion 1 of the cryogenic cable 10 is connected to the terminal portion of the cryogenic cable (superconducting cable) 10 and the superconducting conductor layer (conductor) 112 of the cryogenic cable 10 to draw current out. And the terminal part of the cryogenic cable 10 are accommodated, the refrigerant tank 21 into which the refrigerant N is introduced during operation, and the vacuum tank 22 that accommodates the refrigerant tank 21 and is in a vacuum state during operation. . The terminal connection portion 1 is provided so as to protrude from the refrigerant tank 21 in the axial direction of the refrigerant tank 21, and at least one end of the cryogenic cable 10 is at the center position of the refrigerant tank 21 and the cryogenic cable 10. Rod portion 82 and metal flange portion 84 (cable holding member 80) that are movably held in the extending direction.
The cable holding member 80 supports the baffle plate 200 in a state insulated from the refrigerant tank 21 (specifically, the peripheral wall of the refrigerant tank 21) in the refrigerant tank 21 which is a heat insulating inner tube.

  That is, the baffle plate 200 having an insulating property is suspended from a rod portion 82 protruding from the refrigerant tank 21 together with the terminal portion of the cryogenic cable 10, and is movable in the axial direction by the rod portion 82. And it arrange | positions in the center position of the refrigerant tank 21. FIG. Here, the end portion of the cryogenic cable 10 is cantilevered and supported by the tip portion 211 of the refrigerant tank 21 via the rod portion 82 and the metal flange portion 84 in a simple configuration. Further, the cryogenic cable 10 can be moved in the extending direction via the rod portions 82 </ b> A and 82 </ b> B and can be held in the refrigerant tank 21 at the center position of the refrigerant tank 21.

Thereby, according to the termination | terminus connection part 1, the baffle plate 200 is between the introduction part 92, the interface vicinity X, and the electric field relaxation part 32 vicinity Y including the circumference | surroundings of the electric field relaxation part 32 by the rod part 82. It is in a suspended state. Thereby, the length of the flow path of the refrigerant N introduced from the introduction part 92 to the vicinity of the interface X and the vicinity of the electric field relaxation part 32 including the periphery of the electric field relaxation part 32 can be increased.
Thereby, the pressure fluctuation generated by starting the driving of the circulation pump 9 is propagated to the refrigerant N in the refrigerant tank 21 through the refrigerant N introduced into the refrigerant tank 21. The refrigerant N introduced into the refrigerant tank 21 through the introduction part 92 is inhibited by the baffle plate 200 from propagating fluctuations, bypasses the baffle plate 200, and near the interface X and around the electric field relaxation part 32. The pressure at the time of reaching the vicinity Y of the electric field relaxation part 32 including can be reduced.

  FIG. 5 is a diagram showing fluctuations in the behavior of the refrigerant that are caused by pressure fluctuations generated by the activation of the circulation pump 9. 5A shows the fluctuation of the behavior of the refrigerant near the interface X shown in FIG. 1, and FIG. 5B shows the fluctuation of the behavior of the refrigerant in the vicinity of the electric field relaxation portion 32 including the periphery of the electric field relaxation portion 32. In each figure, for comparison with the termination connection portion 1 of the present embodiment, fluctuations in refrigerant behavior in the vicinity of the interface X and the vicinity of the electric field relaxation portion 32 in the termination connection portion 1 of the present embodiment are shown. In the terminal connection portion 1 of the present embodiment, the solid line indicates the behavior fluctuation of the refrigerant in the vicinity of the interface X and the vicinity of the electric field relaxation portion 32 in the structure excluding the baffle plate 200 by a one-dot chain line.

As shown in FIG. 5A and FIG. 5B, the book which preferably has the baffle plate 200 when the circulating pump 9 (see FIG. 1) is activated and when fluctuations occur in the structure without the baffle plate 200 after a predetermined time. In the terminal connection portion 1 of the embodiment, almost no fluctuation occurs. Thereby, it was found that the baffle plate 200 suppresses fluctuations in the vicinity of the interface X and in the vicinity of the electric field relaxation portion 32 Y. Thereby, in the terminal connection part 1 of this Embodiment, since fluctuation | variation is suppressed by the electric field relaxation part 32 vicinity Y and the interface vicinity X, temperature does not rise in the part, thermal efficiency does not fall, and a superconducting cable Energizing performance (critical current value) can be secured.
As described above, according to the present embodiment, when the refrigerant is introduced at the time of starting the circulation pump 9, the superconducting cable is cooled and maintained at a low temperature state even during the circulation operation by the circulation pump 9, and stable. The superconducting characteristics can be obtained.

  Further, according to the present embodiment, even when the cryogenic cable 10 is thermally contracted, the end of the cryogenic cable 10 is absorbed by the sliding on the rod portion 82 fixed to the refrigerant tank 21. Thus, no load is applied to the refrigerant tank 21 itself.

  In addition, when the refrigerant tank 21 is thermally contracted in the axial direction, the thermal contraction in the axial direction of the refrigerant tank 21 is absorbed by the movement of the rear end portion 212, and accordingly, the rod portion 82 is also connected to the cryogenic cable 10. The plate 200 can be moved in the axial direction without applying a load.

  Thus, according to the termination | terminus connection part 1, the cryogenic cable 10 used as a high voltage is located in the center of the refrigerant tank 21 which functions as a ground, arrange | positioning the cryogenic cable 10 in the center position of the refrigerant tank 21. FIG. Thus, the distance from the refrigerant tank 21 can be maintained at a constant distance. Further, the refrigerant tank 21 or the cryogenic cable 10 can cope with thermal contraction in the axial direction of the refrigerant tank 21 or the cryogenic cable 10. That is, the cryogenic cable 10 can be arranged at the center position of the refrigerant tank 21 while corresponding to the thermal contraction of the refrigerant tank 21 or the cryogenic cable 10 in the axial direction.

  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.

  For example, the end connection part 1 is configured to support the terminal part of the cryogenic cable 10 and the baffle plate 200 in a cantilever state via a rod part 82 protruding from the tip part 211 of the refrigerant tank 21. Not only this but the rod part 82 is good also as a structure extended to the rear-end part 212 of the refrigerant tank 21. FIG. That is, the rod portion 82 is installed between the front end portion 211 and the rear end portion 212 in the refrigerant tank 21 so as to extend in the axial direction. In this manner, the rod portion 82 is inserted into the metal flange portion 84 attached to the terminal portion of the cryogenic cable 10 and the through hole 230 of the baffle plate 200. As a result, the end portion of the cryogenic cable 10 is supported by the rod portion 82 so as to be movable in the axial direction (extending direction) at the center position of the refrigerant tank 21, and the baffle plate 200 is placed inside the refrigerant tank 21. It is good also as a structure suitably arrange | positioned in the position close | similar to a surrounding surface.

  In the present embodiment, the baffle plates 200 are arranged so that the cutout portions 220 of the plurality of baffle plates 200 are arranged in the axial direction. However, the present invention is not limited to this, and in the structure of FIG. May be arranged at different positions. For example, as shown in FIG. 4, in the end connection portion 1 </ b> A having the same structure as that of the end connection portion 1 in FIG. 1, the positions of the notch portions 220 of the baffle plate 200 </ b> A may be alternately arranged up and down. In addition, in the termination | terminus connection part 1A shown in FIG. 5, the same code | symbol and the same name are attached | subjected to the component similar to the termination | terminus connection part 1, and description is abbreviate | omitted. The terminal connection portion 1 </ b> A shown in FIG. 4 can exhibit the same effects as the terminal connection portion 1.

  Moreover, although the cable holding member 80 is configured to have the rod portion 82 and the metal flange portion 84 in the present embodiment, the configuration is not limited thereto. The cable holding member 80 is provided so as to protrude from the refrigerant tank 21 in the axial direction of the refrigerant tank 21, and the terminal portion of the cryogenic cable 10 is located at the center position of the refrigerant tank 21 and in the extending direction of the cryogenic cable 10. Any configuration may be used as long as it can be held movably. In this case, the cable holding member 80 is configured to insulate the refrigerant tank 21 from the cryogenic cable 10.

  For example, the cable holding member 80 may be an insulating cylinder member that protrudes in the axial direction of the refrigerant tank 21 from the inner surface of the front end portion 211 of the refrigerant tank 21. In this case, the insulating cylindrical material protruding in the axial direction of the refrigerant tank 21 in a cantilevered state from the tip portion 211 is inserted into the opening of the tip of the cryogenic cable 10 and the inserted terminal portion is connected to the insulating cylinder. The inner peripheral surface of the material is configured to be held at the center position of the refrigerant tank 21 and movably in the extending direction of the cryogenic cable 10.

  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.

DESCRIPTION OF SYMBOLS 1, 1A terminal connection part 10 Cryogenic cable 9 Circulation pump 11 Cable core 12 Heat insulation pipe 13 Electrode part 14 Shield connection terminal 15 Electric field relaxation layer 20 Low temperature container 21 Refrigerant tank 21A Refrigerant tank main body 21B Shield outlet 21C Draw-out cylindrical part 22 Vacuum tank 22A Vacuum tank body 22B First cylindrical part 22C Second cylindrical part 30 Conductor lead-out part 32 Electric field relaxation part 40 Shield energization part 50 Steel pipe 51 Polymer sleeve 51a Insulating cylinder 51b Cover 52 Polymer shield metal 52a Cylindrical part 52b Flange part 61 Measuring pipe 70 Partition unit 71 Baffle plate 80 Cable holding member 82, 82A, 82B Rod part 82a One end part 83 Metal fitting 84 Metal flange part 85 Fastening part 86 Rod insertion hole 90 Supply pipe 92 Introducing part 111 Former 112 superconducting conductor layer ( Body)
113 Electrical insulation layer 114 Cable shield layer 115 Protective layer 121 Heat insulation inner tube 122 Heat insulation outer tube 200 Baffle plate 210 Plate body portion 211, 221 Tip portion 212, 222 Rear end portion 220 Notch portion 230 Through hole 2111 Rod mounting hole

Claims (4)

The end of the cryogenic cable,
An electrode part connected to the conductor of the terminal part of the cryogenic cable, and for drawing an electric current to the outside;
A refrigerant tank that accommodates the terminal part of the cryogenic cable and the electrode part, and into which refrigerant is introduced during operation,
A vacuum chamber that houses the refrigerant tank and is in a vacuum state during operation;
A cable holding member that protrudes from the refrigerant tank in the axial direction of the refrigerant tank and holds a terminal portion of the cryogenic cable at a central position of the refrigerant tank;
Have
The cable holding member is provided with a baffle plate positioned between the introduction part into which the refrigerant is introduced and the electrode part,
Cryogenic cable termination connection. The cable holding member is
A rod provided to project in the axial direction of the refrigerant tank from the end face of the refrigerant tank located on the tip side of the cryogenic cable in the extending direction of the cryogenic cable;
The termination | terminus connection part of the cryogenic cable of Claim 1. The baffle plate has a plate body portion having an area substantially equal to the inner area of the refrigerant tank, and a notch portion is formed in a part of the plate body portion.
The termination | terminus connection part of the cryogenic cable of Claim 3. A plurality of the baffle plates are installed,
The termination | terminus connection part of the cryogenic cable as described in any one of Claim 1 to 3.

Images