JP2013178959A - Superconductive cable system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconductive cable system constituted so that a circuit of coolant is not branched from an aggregating flow channel to a plurality of individual flow channels.SOLUTION: A system S1 includes: convergence cable parts 100A formed by storing a plurality of cores in one heat insulating tube α in block at an intermediate part of a superconductive cable line; branch cable parts 100B formed by branching the respective cores to be stored in individual heat insulating tube β on both ends of the cable line; and a cooling mechanism 200 for cooling coolant for maintaining the cores at ultralow temperature, and circulating the coolant to a circuit passing through both cable parts 100A, 100B. The circuit includes: an aggregating flow channel AC formed in the convergence cable part 110A; and individual flow channels BC formed in the respective branch cable parts 110B; flow channel transition parts T1, T2 which permit distribution of the coolant from at least one of the individual flow channels BC to the aggregating flow channel AC; and a flow channel division part 300 which prevents that the coolant is distributed from the aggregating flow channel AC to the plurality of individual flow channels BC.

Description

  The present invention relates to a superconducting cable system including a superconducting cable that houses a plurality of cable cores in one heat insulating tube. In particular, the present invention relates to a superconducting cable system configured so that the flow of the refrigerant does not branch from one to a plurality in the refrigerant circulation path provided in the superconducting cable system.

  In general, a superconducting cable includes a cable core having a superconducting conductor layer formed on the outer periphery of the former, and a cable insulation pipe that accommodates the cable core. The cable core is cooled to a cryogenic temperature with a refrigerant such as liquid nitrogen. Used (see, for example, Patent Document 1).

  As such a superconducting cable, as shown in FIG. 10, a superconducting cable 100 in which a plurality of cable cores 110 are housed in one cable heat insulating tube 120 is known.

  A representative cable core 110 includes, in order from the center, a former 111, a superconducting conductor layer 112, an internal semiconductive layer (not shown), a cable insulating layer 113, an external semiconductive layer (not shown), a cable shielding layer 114, A protective layer 115 is provided. The typical cable heat insulation pipe 120 includes an inner pipe 121 and an outer pipe 122, and the space between the pipes 121 and 122 is evacuated. Further, an anticorrosion layer 123 is formed on the outer periphery of the outer tube 122. Usually, the space between each cable core 110 and the heat insulation pipe 120 is used as a refrigerant flow path.

  FIG. 11 is a schematic diagram showing a configuration of a conventional superconducting cable system using the three-core superconducting cable 100 shown in FIG. In this superconducting cable system Sc, each cable core 110 is branched by a converging cable part 100A in which a plurality of cable cores are housed in one cable insulation pipe α, and branch boxes 150 at both ends of the converging cable part 100A. And a branch cable portion 100B housed in the heat insulation pipe β. Each of the branched cable cores 110 is accommodated in the individual heat insulating tube β and electrically connected to the terminal portion 100E. By providing the terminal portions 100E individually at the ends of the cable cores 110, the individual terminal portions 100E can be made compact, and a high degree of freedom can be secured with respect to the installation locations of the terminal portions 100E.

  In the superconducting cable system Sc, a refrigerant circulation path for cooling each cable core to an extremely low temperature is formed (for example, see Patent Document 2).

  The circulation path of the system Sc is configured as a single circulation path through which the refrigerant flows in the following order. First, refrigerant is sent from the cooling mechanism 200 having the reservoir tank 210, the pump 220, and the refrigerator 230 to each branch cable portion 100B via the supply pipe Cg and the terminal portion 100E on one end side (left side in FIG. 11) of the superconducting cable 100. It is. The refrigerant that has passed through the individual forward path Bg (individual flow path BC) in each branch cable section 100B is collected in the focusing cable section 100A via one branch box 150 to form a collective flow path AC, and the superconducting cable 100 It is distributed to the other end side (the right side in FIG. 11). Furthermore, the refrigerant that has passed through the collecting channel AC is branched and distributed on the other end side of the superconducting cable 100 to the individual forward path Br (individual channel BC) in each branch cable portion 100B via the other branch box 150. After that, it is returned to the cooling mechanism 200 through the other terminal portion 100E and the discharge pipe Cr.

JP 2011-28936 JP2003-297161

  However, as a result of the study by the present inventors, it has been found that in the conventional superconducting cable system Sc shown in FIG. 11, there is a possibility that the cooling degree of each cable core 110 in the branch cable portion 100B may vary. One of the causes is that the refrigerant does not sufficiently divert to each of the individual return paths Br from the other end side (the right side of FIG. 11) of the collective flow path AC, and therefore the branch cable. For example, the degree of cooling of the cable cores 110 in the portion 100B may vary.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a superconducting cable system configured so that the refrigerant circulation path does not branch from the collecting flow path to a plurality of individual flow paths. There is.

  The inventors of the present invention configure one circulation path so as to allow the refrigerant to flow from at least one individual flow path to the collective flow path but prevent the flow from the collective flow path to a plurality of individual flow paths. As a result, the inventors have obtained knowledge that the above object can be achieved, and have completed the present invention.

  The superconducting cable system of the present invention includes a converging cable part, a branching cable part, and a cooling mechanism. In the converging cable portion, a plurality of cable cores are collectively accommodated in one heat insulating tube α at an intermediate portion of the superconducting cable line. The branch cable portion branches the cable cores at both ends of the superconducting cable line and stores them in individual heat insulating tubes β. The cooling mechanism cools the refrigerant that maintains the cable core at a very low temperature, and circulates the refrigerant in a circulation path that passes through the converging cable portion and the branch cable portion. In such a system, the circulation path includes a collective flow path formed in the converging cable portion and an individual flow path formed in each branch cable portion. The circulation path prevents the refrigerant from being divided into a plurality of individual flow paths from the collective flow path, and a flow path transition portion that allows the refrigerant to flow from at least one of the individual flow paths to the collective flow path. And a flow channel section.

  According to this configuration, the flow path of the refrigerant from the converging cable portion to the branch cable portion can be secured by allowing the flow of the refrigerant from the collective flow path to the individual flow path by the flow path transition portion. On the other hand, by preventing the refrigerant from being diverted from the collective flow path to the plurality of individual flow paths by the flow path partitioning section, it is possible to suppress variation in the cooling degree of the cable core of each branch cable section. In particular, it is easy to distribute the refrigerant in each individual channel evenly without providing a control unit for the refrigerant flow rate in the individual channel of each branch cable portion.

  The branch of the cable core between the heat insulation pipe α and the heat insulation pipe β is a series of cores of the focusing cable portion and the branch cable portion, and a branch box is provided on the end side of the superconducting cable line. In addition to the case where multiple cores are separated from each other in the branch box, the core of the converging cable part and the core of the branch cable part are separate cores. This includes the case where the cores of the branch cable part are separated from each other on the end side of the superconducting cable line from the box.

  In this superconducting cable system, the refrigerant circulation path may be single or plural. In addition, the flow path of the refrigerant in the superconducting cable line includes a plurality of cores in addition to the space between the heat insulation pipe α and the cable core group of the converging cable part, the space between the heat insulation pipe β of the branch cable part and each cable core In some cases, the former of at least a part of the core is a hollow pipe and the space in the pipe is used.

  In this superconducting cable system, a cooling mechanism for cooling and circulating the refrigerant is used. A typical example of the cooling mechanism includes a configuration including a reservoir tank, a pump, and a refrigerator. However, various forms can be used for specific combinations of the reservoir tank, the pump, and the refrigerator. For example, when each member is arranged in series in the order of reservoir tank → pump → refrigerator from the downstream side to the upstream side of the refrigerant (independent type), or a reservoir with a refrigerator that cools the refrigerant in the reservoir tank with the refrigerator There is a case (composite type) in which each member is arranged in series in the order of tank → pump. In any case, in principle, the pump is located downstream of the reservoir tank. With this arrangement, the pressure of the circulated refrigerant is minimized just before the reservoir tank or pump.

In addition, each of the pump and the refrigerator may be used in the same number as the number of individual flow paths (number of cable cores), or may be different from the number of individual flow paths (number of cable cores). . More specifically, the following structure is mentioned.
(A) The number of pipes corresponding to the number of individual flow paths is extended from the reservoir, and pumps and refrigerators are arranged in series in the respective pipes (number of pumps = number of refrigerators = number of individual flow paths).
(B) The number of pipes that are less than the number of each individual flow path is extended from the reservoir, a pump is provided in the pipe, and the downstream of the pump is connected to the number of branch pipes corresponding to the number of each individual flow path. Install a refrigerator in the branch pipe (number of pumps <number of individual channels, number of refrigerators = number of individual channels).

  Furthermore, when the superconducting cable system includes a plurality of refrigerant circulation paths, the refrigerant cooling mechanism in each circulation path may have the same configuration or a different configuration. For example, when two circulation paths are provided, the cooling mechanism of one circulation path may be the independent type, and the cooling mechanism of the other circulation path may be the combined type.

  As one form of the superconducting cable system of this invention, the said circulation path has a form provided with the 1st circulation path and the 2nd circulation path which were mutually independent. In that case, the first circulation path has a first individual flow path provided on one end side of the superconducting cable line, and a first collective flow path connected to the first individual flow path via the first flow path transition portion. . The second circulation path has a second individual flow path provided on the other end side of the superconducting cable line, and a second collecting flow path connected to the second individual flow path via a second flow path transition portion. And the said flow-path division part has a collection flow-path division part which divides a 1st collection flow path and a 2nd collection flow path.

  According to this configuration, the superconducting cable system having the converging cable portion and the branch cable portion can be circulated using at least two refrigerant circulation paths. At that time, in any system circulation path, the circulation of the refrigerant from the individual flow path of each system to the collective flow path of each system is permitted by the flow path transition section of each system. On the other hand, since the first collective flow channel and the second collective flow channel are partitioned by the collective flow channel partitioning section, the refrigerant is not divided from the collective flow channel of each system to the individual flow channel of each system. . Therefore, it can suppress that variation arises in the cooling degree of the cable core of each branch cable part.

  As one form of the superconducting cable system of the present invention including the first circulation path and the second circulation path, at least one of the first individual flow path and the second individual flow path is configured in parallel for each cable core. The form currently made is mentioned. In that case, all of the individual flow paths arranged in parallel are connected to at least one of the first collective flow path and the second collective flow path via at least one of the first flow path transition section and the second flow path transition section. .

  According to this configuration, a circulation path in which the individual flow paths in the plurality of branch cable portions are arranged in parallel can be configured. Therefore, basically, a pump that pumps the refrigerant for each individual flow path is required, but the output of each pump can be relatively small.

  As one form of the superconducting cable system of the present invention, at least one of the first individual flow path and the second individual flow path is configured in a series along all cable cores, and one of the individual flow paths along each cable core. A form in which only one is connected to at least one of the first collective flow path and the second collective flow path via the flow path transition portion can be mentioned. In that case, the flow path partitioning section has an individual flow path partitioning section that partitions the remaining individual flow paths excluding one individual flow path connected to the collective flow path from the collective flow path.

  According to this configuration, the circulation path can be configured by using the individual flow paths in the plurality of branch cable portions as a series of flow paths. In other words, the refrigerant in each individual flow channel is circulated in series so as to write a plurality of branch cable portions. Therefore, basically, the refrigerant can be circulated by using one pump for the individual flow paths formed in series in the plurality of branch cable portions.

  As one form of the superconducting cable system of the present invention, the circulation path is configured by a single circulation path, and the individual flow paths are individually formed on one end side individually along all cable cores on one end side of the superconducting cable line. The form which has a flow path and the other end side separate flow path formed in series along all the cable cores of the other end side of a superconducting cable track is mentioned. In this case, the collecting channel is configured to connect the one end side individual channel and the other end side individual channel.

  According to this configuration, the refrigerant flows from the collective flow path to the other end-side individual flow path while forming a single circulation path connecting the one-end-side individual flow path, the collective flow path, and the other end-side individual flow path. Since it is not branched into a plurality of individual flow paths but performed on a series of individual flow paths, it is possible to suppress variations in the cooling degree of the cable core of each branch cable portion.

  As one form of the superconducting cable system of the present invention, the first individual flow path and the second individual flow path are formed in a space between the heat insulating pipe β and each core, and the first collective flow path and the second collective flow path are It is mentioned that it is formed in the space between the heat insulating pipe α and each core.

  According to this configuration, since the refrigerant flow path is formed outside each cable core, it is easy to supply and discharge the refrigerant to both the branch cable portion and the converging cable portion.

  As one form of the superconducting cable system of the present invention, the superconducting cable includes a heat insulating tube α, an outer flow path through which a refrigerant flows in a space between the heat insulating tube β and each cable core, and a hollow former provided in each cable core. The form provided with the inner side flow path through which a refrigerant | coolant distribute | circulates to internal space is mentioned. In that case, the above-mentioned circulation path is the cooling mechanism → the outer flow path in the branch cable part on one end side of the superconducting cable line → the inner flow path in the branch cable part on one end side of the superconducting cable line → the inner side in each core in the focusing cable part It is circulated in the order of flow path → inner flow path in the branch cable section on the other end of the superconducting cable line → outer flow path in the branch cable section on the other end side of the superconducting cable line → outer flow path in the converging cable section → cooling mechanism. It consists of a single circulation path. And the said flow-path division part divides the outer flow path in the branch cable part in the one end side of a superconducting cable track | line, and the outer flow path in a focusing cable part.

  According to this configuration, a superconducting cable system having a single circulation path can be constructed by using not only the space between each core and the heat insulating pipe but also the internal space of the former as the refrigerant flow path.

  As one form of the superconducting cable system of the present invention, the superconducting cable includes a heat insulating tube α, an outer flow path through which a refrigerant flows in a space between the heat insulating tube β and each cable core, and a hollow former provided in each cable core. The form provided with the inner side flow path through which a refrigerant | coolant distribute | circulates to internal space is mentioned. In this case, the circulation path includes a main circulation path and a sub circulation path that are independent of each other. The main circuit consists of a cooling mechanism, an inner flow path in the branch cable section on one end side of the superconducting cable line, an inner flow path in each core in the focusing cable section, and an inner flow path in the branch cable section on the other end side of the superconducting cable line. The refrigerant is circulated in the order of the outer flow path in the branch cable portion on the other end side of the superconducting cable line, the outer flow path in the focusing cable portion, and the cooling mechanism. In the secondary circuit, the refrigerant is circulated in the order of the cooling mechanism → the outer flow path in the branch cable portion on one end side of the superconducting cable line → the outer flow path in the focusing cable portion → the cooling mechanism. And a flow path division part partitions the outer flow paths in the focusing cable part of a main circuit and a sub circuit.

  According to this configuration, a superconducting cable system having a plurality of circulation paths can be constructed by using not only the space between each core and the heat insulating pipe but also the internal space of the former as the refrigerant flow path.

  Since the superconducting cable system of the present invention does not have a portion where the flow of the refrigerant branches from one to a plurality, it is easy to adjust the flow rate of the refrigerant in each branch cable portion, and the variation in cooling of the cable core can be suppressed.

(A) is the schematic of the refrigerant | coolant circulation path in the superconducting cable system which concerns on Embodiment 1, (B) is a partially expanded view of the circulation path shown to (A). 6 is a schematic diagram of a refrigerant circulation path in a superconducting cable system according to Embodiment 2. FIG. 6 is a schematic diagram of a refrigerant circulation path in a superconducting cable system according to Embodiment 3. FIG. (A) is the schematic of the refrigerant | coolant circulation path in the superconducting cable system which concerns on Embodiment 4, (B) is the elements on larger scale of the one end side of the circulation path shown to (A), (C) is the circulation shown to (A). It is the elements on larger scale of the other end side of a path. (A) is the schematic of the circulation path of the refrigerant | coolant in the superconducting cable system which concerns on Embodiment 5, (B) is the elements on larger scale of the one end side of the circulation path shown to (A), (C) is the circulation shown to (A). It is the elements on larger scale of the other end side of a path. It is a partial schematic block diagram of a terminal that can be used in the systems according to Embodiments 1, 2, and 3. It is a partial schematic block diagram of the terminal which can be used for the system which concerns on Embodiment 4,5. It is a schematic block diagram of the connection part which can be utilized for the system which concerns on Embodiment 2, 3. FIG. It is a connection part which can be utilized for the system which concerns on Embodiment 5, and is a schematic block diagram which shows the connection part of a superconducting cable and a normal conducting cable. It is a schematic cross-sectional view of a superconducting cable having a three-core cable core. It is the schematic of the conventional superconducting cable system.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The members common to the embodiments are denoted by the same reference numerals, and description thereof is omitted.

<Basic configuration of each embodiment>
In any of the embodiments, a known low-temperature insulated superconducting cable such as the superconducting cable shown in FIG. 10 can be used. In addition, the system according to each embodiment includes (1) a converged cable in which a plurality of cable cores (sometimes simply referred to as cores in the following description) are collectively stored in one heat insulating tube α having a large diameter. And a branch cable portion for branching each cable core at both ends of the focusing cable portion and storing each of the branched cores in a small-diameter individual heat insulating tube β, (2) a reservoir tank, The refrigerant is circulated in the circulation path that passes through the converging cable section and the branch cable section using a cooling mechanism having a pump and a refrigerator, and (3) there are branch boxes at both ends of the converging cable section composed of superconducting cables. However, it is the same as the superconducting cable system shown in FIG. 11 in that each core is separated in the branch box or (4) a terminal part is formed at the end of the branch cable part. However, there may be a case where a junction box is provided at both ends of the converging cable portion, and the branch cable portion is configured by connecting the core of the converging cable portion to another core in the junction box (Embodiments 2 and 3). In the description of each of the following embodiments, FIGS. 1 to 5 are configurations related mainly to a refrigerant circulation path, with the left side of the drawing being one end side (one side) of the superconducting cable system and the right side being the other end side (the other side). The other structure of the superconducting cable system is simplified.

  In any of the embodiments, various known configurations such as the configuration of JP-A-2005-12925 can be used as the branch box, and the description of the specific configuration is omitted. In addition, a known configuration such as the configuration described in Japanese Patent Application Laid-Open No. 2006-196628 can be applied to the terminal unit. However, in each of the first to fifth embodiments, the refrigerant is introduced into the branch cable unit, or the branch cable is used. The configuration of the terminal part suitable for discharging from the part is Embodiments 6, 7, and 9. In the connection boxes (connections) for connecting the refrigerant flow paths formed in the former core formers in Embodiments 2 and 3 Unit) will be described in the eighth embodiment.

<Embodiment 1>
Referring to FIG. 1, the superconducting circuit has a configuration in which the refrigerant circulation path is composed of two systems of a first circulation path and a second circulation path, and individual flow paths (individual forward paths) in each branch cable portion 100B are arranged in parallel. The cable system S1 will be described. In this example, all the circulation paths are arranged in order from the cooling mechanism 200 including the refrigerator 210 and the pump 220, the first and second individual forward paths B1 and B2 (individual flow paths BC), the collective flow path AC, and the first and second flow paths. The refrigerant is circulated in the order of the return paths C1 and C2 (return path CC) and the cooling mechanism 200. A superconducting cable 100 used in the system S1 is a three-core batch type superconducting cable similar to that shown in FIG. 10, and each cable core includes a former having a stranded wire structure in which a plurality of copper wires insulated from each other are twisted together. For this reason, the refrigerant flow path includes the collective flow path AC formed in the space between the heat insulation pipe α and the three core groups, and the individual flow path BC formed in the space between the heat insulation pipe β and each core 110. And have.

  The first circulation path includes a supply pipe Cg1 connected from the cooling mechanism 200 to one terminal part 100E, a first individual forward path B1 (first individual flow path) formed in the heat insulating pipe β connected to the terminal part 100E, the first The first collective flow path A1 is formed in the heat insulating pipe α from the individual forward path B1 via the first flow path transition portion T1, and the first return path C1 is connected to the first collective flow path A1. A total of three first individual forward paths B1 are provided in parallel corresponding to each of the cable cores 110, and one each of the first collective flow path A1 and the first return path C1 is provided. A well-known configuration can be used as the connection structure itself that performs electrical connection between the superconducting conductor layer constituting each cable core 110 and the normal conducting lead constituting the terminal portion 100E. The points related to these connection structures are the same in the second individual outbound path B2, which will be described later.

  The first flow path transition portion T1 is a place where the three thin first individual forward paths B1 are collectively moved by the branch box 150 and transferred to the thick first collective flow path A1. On the other hand, the transition portion from the thick first collective flow path A1 to the thin first return path C1 does not change the number of flow paths, and only changes the size of the diameter of the flow paths. The same applies to a second flow path transition portion T2 and a transition portion from the second collecting flow path A2 to the thin second return path C2, which will be described later.

  The second circulation path is substantially symmetric with the first circulation path. Specifically, the supply pipe Cg2 connected from the cooling mechanism 200 to the other terminal part 100E, the second individual forward path B2 (second individual flow path) formed in the heat insulating pipe β connected to the terminal part 100E, the second individual The second collective flow path A2 is formed in the heat insulating pipe α from the forward path B2 via the second flow path transition portion T2, and the second return path C2 is connected to the second collective flow path A2. A total of three second individual forward paths B1 are provided corresponding to each of the cable cores, and one each of the second collective flow path A2 and the second return path C2 is provided.

  The first collective flow path A1 and the second collective flow path A2 are partitioned into one end side and the other end side by the collective flow path partitioning section 310 in the heat insulating pipe α (FIG. 1 (A), ( B)). By this collective flow path partitioning section 310, the first circulation path and the second circulation path are configured as independent system circulation paths. A through-hole through which each core 110 penetrates is formed in the collective flow passage partition portion 310, between the inner peripheral surface of each through-hole and each core 110, and between the outer peripheral surface of the collective flow passage partition portion 310 and the heat insulating tube α. A space between the inner peripheral surface and the liquid refrigerant is sealed in a watertight manner. In this example, the position of the collective flow path partitioning section 310 is provided in the branch box 150 on the other end side of the converging cable section 100A, but the longitudinal position of the converging cable section 100A and each branch box 150 is limited. However, it may be provided in the branch box 150 at the center or one end side of the focusing cable portion 100A. This also applies to Embodiments 2 and 5 described later that divide the collecting channel AC into two at one end side and the other end side.

  In the system S1 of this example, as the cooling mechanism 200, the composite cooling mechanism 200 is used for the first circulation path, and the independent cooling mechanism 200 is used for the second circulation path. That is, in the first circulation path, the reservoir tank 210 with the refrigerator 230 is connected to the first return path C1, the three supply pipes Cg1 are extended from the tank 210, and the pumps 220 are provided in the individual supply pipes Cg1. . On the other hand, in the second circulation path, a reservoir tank 210 is connected to the second return path C2, three supply pipes Cg2 are extended from the tank 210, and a pump 220 is provided in each supply pipe Cg2. By using these six pumps 220 in total, it is possible to individually control the flow rate of the refrigerant to each of the individual forward paths B1 and B2. Of course, the cooling mechanism of both circulation paths may be the same in either the independent type or the combined type, the cooling mechanism of the first circulation path may be the independent type, and the cooling mechanism of the second circulation path may be the combined type. It is the same in other embodiments described later that various options can be adopted for the form of the cooling mechanism.

  By forming such two circulation paths, even though the refrigerant flow from the plurality of first (second) individual outbound paths B1, B2 to the first (second) collective outbound paths A1, A2 is allowed, The return paths from each of the first (second) gathering paths A1 and A2 to the cooling mechanism 200 are the first (second) return paths C1 and C2. In other words, there is no place where the refrigerant is diverted from the first (second) collecting outward paths A1 and A2 to the plurality of individual flow paths. Therefore, it can suppress that the cooling degree of each core in each branch cable part 100B varies.

<Embodiment 2>
Next, referring to FIG. 2, a superconducting cable system S2 in which the refrigerant circulation path is composed of two systems of the first circulation path and the second circulation path, and the individual flow paths in each branch cable section are configured in series. explain.

  This system S2 also has first and second circulation paths, and each circulation path has first and second individual outbound paths B1u, B1v, B1w, B2u, B2v, B2w, and a superconducting cable of a three-core batch type. This is common with the first embodiment. However, in this example, a connection box (see connection unit 400: refer to Embodiment 8) is provided at both ends of the superconducting cable instead of a branch box, and another terminal is connected to both ends of the superconducting cable 100X located in the middle via the connection unit 400. Superconducting cable 100Y is connected. Among the cores of each of these superconducting cables 100X and 100Y, one core having the first individual forward path B1u and one core having the second individual forward path B2u are the same as in the first embodiment using the former made of stranded wires. The other two cores having the first individual outbound paths B1v and B1w and the other two cores having the second individual outbound paths B2v and B2w use a hollow pipe former, and the interior of the former is also It differs from the first embodiment in that it is a refrigerant flow path. The former one core includes only the outer flow path OC between the heat insulating tube β and the core, while the other two cores of the latter also include the inner flow path IC in the former of the hollow pipe in addition to the outer flow path OC. Prepare. In FIG. 2, the inside of the thin tube showing the other two cores 110 of the latter also shows the inner flow path IC in the former 111 (FIG. 10) (the same applies to FIG. 3 described later).

  Further, unlike the first embodiment, the first and second individual forward paths B1u, B1v, B1w, B2u, B2v, and B2w of this example connect the flow paths of the branch cable portions 100B in series. That is, the cooling mechanism 200 side of the u-phase first individual outbound path B1u → the first aggregate flow path A1 side of the u-phase first individual outbound path B1u → the first aggregate path A1 side of the v-phase first individual outbound path B1v → Coolant 200 side of v-phase first individual outbound path B1v → Cooling mechanism 200 side of first individual outbound path B1w of w phase → One stroke of refrigerant in order of first aggregate flow path A1 side of first individual outbound path B1w of w phase Distribute to writing. The same applies to the second individual outbound paths B2u, B2v, B2w.

  It is to be noted that the composite cooling mechanism 200 is used for the first circulation path and the independent cooling mechanism 200 is used for the second circulation path, as in the first embodiment.

  In the present example, the first collecting channel A1 and the second collecting channel A2 are partitioned by the collecting channel partitioning section 310 as in the first embodiment. However, in this example, the boundary between the first collective flow path A1 side end of the u-phase first individual flow path B1u and the first collective flow path A1, the first collective flow path of the v-phase first individual flow path B1v A first individual channel partition 320 is formed at each of the boundary between the A1 side end and the first collecting channel A1, and only the first collecting channel A1 side end of the w-phase first individual channel B1w is the first. It is configured to communicate with the one collecting channel A1. This also applies to the second individual flow paths B2u, B2v, B2w. Furthermore, although not shown in figure, in this individual channel division part 320, a through-hole through which each corresponding cable core penetrates is formed, and between the inner peripheral surface of the through-hole and the outer peripheral surface of the cable core, The space between the outer peripheral surface of the individual flow path partition 320 and the inner peripheral surface of the heat insulating pipe β is sealed in a watertight manner with respect to the liquid refrigerant.

  More specifically, with this configuration, the refrigerant is circulated as follows. First, in the first individual outbound path B1u, the refrigerant introduced from the supply pipe Cg1 through the terminal unit 100E is circulated from the terminal unit side to the connection unit 400 side through the outer channel OC. Next, in the first individual outbound path B1v, the refrigerant that has flowed through the first individual outbound path B1u is once circulated through the outer channel OC toward the terminal unit 100E side, and then turned back at the terminal unit 100E to return to the inner channel IC. Is distributed to the connection unit 400 side. The refrigerant circulated from the first individual outward path B1u to the first individual outward path B1v is not separated from the refrigerant of the collective flow path AC by the individual flow path partition 320 and mixed. Further, the refrigerant that has passed through the inner flow path IC of the first individual outbound path B1v is circulated from the connection unit 400 side to the terminal unit 100E side through the inner channel IC of the first individual outbound path B1w, and is folded at the terminal unit 100E. It flows through the outer flow path OC of the first individual outbound path B1w to the connection unit 400 side and is introduced into the collective flow path AC. Specific means for forming such a refrigerant flow path will be described in an eighth embodiment to be described later.

  According to the system S2 having this configuration, the refrigerant is divided into the plurality of individual flow paths BC from the collective flow path AC even if there is a place where the refrigerant is allowed to flow from the single individual flow path BC to the collective flow path AC. There is no place to be done. Therefore, it can suppress that the cooling degree of each core in each branch cable part 100B varies. In addition, since the individual flow path BC of each circulation path is constituted by a series of flow paths, the refrigerant can be circulated by using one pump (two in total) for each circulation path.

  In this configuration, the refrigerant is transferred between the adjacent individual flow paths only on the root side (connection unit 400 side) of the individual flow paths. Therefore, with a simple configuration, it prevents the circulation current from flowing from the terminal side of a certain individual flow path to the root side → the terminal side of the adjacent individual flow path to the terminal side → the terminal part side of a certain individual flow path. be able to. The refrigerant flow path similar to FIG. 2 can be formed by connecting the end portions of adjacent individual flow paths with a bypass pipe. However, in that case, since the adjacent individual flow paths are annularly connected at the base side and the bypass pipe, in order to prevent a circulating current from flowing through the adjacent individual flow paths, the bypass pipe Insulating joints are required. On the other hand, in the configuration of FIG. 2, the circulating current can be prevented from flowing without using an insulating joint.

<Embodiment 3>
Next, the superconducting cable system S3 having a single circulation path is similar to the system of the second embodiment in that the first (second) individual flow path formed in the branch cable portion is a series of flow paths. This will be described with reference to FIG. The following description will focus on differences from the second embodiment.

  In short, the circulation path of the system S3 is the first by replacing the cooling mechanism 200 of the second embodiment with a stand-alone type, and removing the collective flow path partition section 310 and the first (second) return paths C1, C2.・ The second collective flow path A1, A2 is a single collective flow path AC, the first individual forward path B1 at one end is directly used as the individual forward path Bg (one end individual flow path), and the second individual forward path B2 at the other end It can be said that this is an individual return path Br (an individual flow path on the other end side).

  In this configuration, a single circulation path is formed in which the refrigerant flows from the refrigerator 210 via the pump 220 through the individual forward path Bg → single collective flow path AC → individual return path Br and is returned to the refrigerator 210 again. The Specifically, on the refrigerator 210 side of the u-phase individual outbound path Bgu → the collective flow path AC side of the u-phase individual outbound path Bgu → the collective path AC side of the v-phase individual outbound path Bg → the v-phase individual outbound path Bgv The refrigerant is circulated in one stroke in the order from the refrigerator 210 side to the w-phase individual outbound path Bgw on the refrigerator 210 side to the w-phase individual outbound path Bgw on the collecting channel AC side. Of each individual outbound path, only the u-phase individual outbound path Bgu includes only the outer channel OC, and each of the v-phase individual outbound path Bgv and the w-phase individual outbound path Bgw includes the outer path OC and the inner path IC. The point and the point to which the superconducting cables 100X and 100Y are connected via the connection unit 400 are the same as in the second embodiment. The same applies to the individual outbound paths Bru, Brv, and Brw, except that the direction in which the refrigerant flows is reversed from that of the individual outbound path Bg.

  According to this configuration, the passage of refrigerant from the single individual flow path BC (individual forward path Bg) to the collective flow path AC or the single flow path BC (individual return path Br) from the collective flow path AC is allowed. Even if there is a place where the circulation of the refrigerant exists, there is no place where the refrigerant is diverted from the collective flow path AC to the plurality of individual flow paths. Therefore, it can suppress that the cooling degree of each core in each branch cable part 100B varies. Moreover, since there is a single circulation path and a series without parallel portions, only one pump may be used for circulating the refrigerant.

<Embodiment 4>
Next, a superconducting cable system S4 that uses a superconducting cable having a hollow pipe former and also uses the space in the former as a refrigerant flow path to form a single refrigerant flow path will be described with reference to FIG.

  In this system S4, one of the space between the heat insulation pipe α (heat insulation pipe β containing individual cores) that accommodates three cores and the core and the space in the former is used as a refrigerant. The forward path and the other are used as the refrigerant return path to form a single circulation path. In FIG. 4, the inside of the narrow tube showing the core 110 also shows the inner flow path IC in the former 111 (FIG. 10), and the outer side of the core 110 in the branch cable portion 100B is the outer flow between the heat insulating tube β and the core 110. A path OC is shown (the same applies to FIG. 5 described later).

  In each branch cable portion 100B on one end side of the superconducting cable, the individual heat insulation pipe β constituting each branch cable portion 100B is connected to the heat insulation pipe α constituting the focusing cable portion 100A via the branch box 150. Each outer channel OC is partitioned from the collective channel AC by an individual channel partition 320 provided on one end face of the branch box 150. Further, one end side of the former 111 constituting the inner flow path IC passes through the individual flow path partitioning section 320 from the heat insulation pipe α side and opens to the inside of one end side of the heat insulation pipe β. As an actual configuration around the individual flow path partition part, the cable core penetrates the individual flow path partition part 320, between the inner peripheral surface of the individual flow path partition part 320 and the outer peripheral surface of the cable core, and the individual flow. A space between the outer peripheral surface of the road partition 320 and the inner peripheral surface of the heat insulating tube β is sealed in a watertight manner with respect to the liquid refrigerant.

  In the converging cable portion 100A at the intermediate portion of the superconducting cable, the former 111 constituting each inner flow path IC continues from the one end side to the other end side of the cable through the heat insulating pipe α.

  On the other hand, in each branch cable portion 100B on the other end side of the superconducting cable, the individual heat insulation pipe β constituting each branch cable portion 100B is connected to the heat insulation pipe α constituting the focusing cable portion 100A via the branch box 150, The outer channel OC communicates with the collecting channel AC. The other end of the former 111 constituting the inner flow path IC is opened inside the other end side of the heat insulating tube β.

  Here, the refrigerant is supplied from the cooling mechanism 200 to the collective flow path AC side (root side) of the individual heat insulating pipes β via the supply pipe Cg, and introduced into the outer flow path OC. In the case of this example, the supply pipe Cg is connected to the branch box side of the heat insulation pipe β. Further, the number of refrigerant circulation pumps is preferably three in total, corresponding to the number of routes of the supply pipe Cg. The refrigerant introduced into the outer flow path OC flows through the outer flow path OC to the distal end side (terminal side) of each branch cable portion 100B, and the inner flow path opens into the outer flow path OC at the distal end side. Introduced in IC and folded. The refrigerant introduced into the inner flow path IC passes through the inner flow path IC as it is, flows through the branching section 150 to the focusing cable section AC side, and is further superconducted in a state where it is separated from the collective flow path AC in the heat insulating pipe α. The other end of the cable is distributed. On the other end side of the superconducting cable, the inner flow path IC that has passed through the heat insulating pipe α passes through the branching section 150, and the refrigerant flows as it is as the inner flow path IC in the branching cable section 100B. This refrigerant is introduced into the outer flow path OC from the inner flow path IC opened into the heat insulating pipe β on the distal end side (terminal side) of each branch cable portion 100B (FIG. 4A). The refrigerant folded back at the other end of the superconducting cable flows through the outer flow path OC in each heat insulation pipe β, through the branch portion 150, and into the collective flow path AC in the heat insulation pipe α. Then, the refrigerant is returned from the branch part 150 on one end side of the collecting channel AC to the cooling mechanism 200 through the discharge pipe Cr (FIG. 4B). The cooling mechanism 200 is a composite type. In this example, the number of discharge pipes Cr is singular, but may be plural.

  That is, in each branch cable portion 110B on one end side, the outer flow path OC is the forward path and the inner flow path IC is the return path, and in the middle cable section 100A, the inner flow path IC is the forward path and the outer flow path OC is the return path. Thus, in each branch cable portion 100B on the other end side, the inner flow path IC is the forward path, and the outer flow path OC is the return path, so that a circulation path for one system of refrigerant is configured.

  In FIG. 4, for convenience of explanation, of the total three supply pipes Cg corresponding to the number of cores, only the route A is shown in full length, and the routes B and C are shown in the middle. However, in reality, a total of three supply pipes including route B and route C are connected to the base side of each branch cable portion. FIG. 4B shows only the former 111 corresponding to a two-core core for convenience of explanation.

  According to this configuration, not only the space between the heat insulating pipe α (β) and the core, but also the space inside the former 111 can be used as the refrigerant flow path to construct a single circulation path. At that time, the individual flow path section 320 forms a series of the inner flow path IC and the outer flow path OC in the branch cable portion 110B to form an individual flow path. Although the refrigerant is allowed to circulate, the refrigerant is not diverted from the collecting channel AC to the plurality of individual channels. Thereby, it can suppress that the cooling degree of each core in each branch cable part varies. Moreover, the flow volume of a refrigerant | coolant can be controlled for every branch cable part by introduce | transducing a refrigerant | coolant for every core of the branch cable part of each phase. And the number of pumps can be reduced as compared with the first embodiment.

<Embodiment 5>
Next, a superconducting cable system S5 having two circulation paths using a superconducting cable having a hollow pipe former and also using the space in the former as a refrigerant flow path will be described with reference to FIG.

  In this system S5, the configuration of the superconducting cable used and the configuration of the circulation path on the other end side (the right side in FIG. 5) of the superconducting cable are the same as those in the system of the fourth embodiment. On the other hand, the configuration of one end side (left side in FIG. 5) of the superconducting cable is different from the system of the fourth embodiment.

This system S5 includes two circulation paths, a main circulation path (first circulation path) and a secondary circulation path (second circulation path). The main circulation path, at one end of the superconducting cable, the refrigerant is introduced from the inner channel IC ₁ of the branch cable section 100B via the first supply pipe Cg1. The inner flow path IC ₁ passes through the heat insulation pipe β of the branch cable portion 100B and also passes through the branch box 150 and the heat insulation pipe α of the focusing cable portion, and further passes through the branch box 150 on the other end side of the superconducting cable. It reaches to the tip side in the part 100B. That is, one end side of the inner flow channel IC ₁ 'is connected to the cooling mechanism 200 through the first supply pipe Cg1, the other end is opened to the heat insulating tube β in the branch cable section 110B. The refrigerant discharged from the opening is folded and through the splitter box 150 through the outside flow path OC ₁ in the other end of the branch cable section 110B to the first set channel A1 in the heat-insulated pipe alpha. Then, the refrigerant is returned to the cooling mechanism 200 from the branch box 150 on one end side of the first collecting channel A1 via the first discharge pipe Cr1.

On the other hand, the sub-circulation path, at one end of the superconducting cable, the refrigerant is introduced from the tip end of the insulating tube β to the outer channel OC ₂ of the branch cable section 110B via the second supply pipe Cg _2. The heat insulation pipe β is connected to the heat insulation pipe α, and the outer flow path OC ₂ in the heat insulation pipe β is communicated with the second collecting flow path A 2 in the branch box 150. The second collecting flow path A2 in the heat insulating pipe α is connected to the circulation mechanism through the second discharge pipe Cr2.

  Such a main circulation path and a secondary circulation path are formed by dividing the collective flow path in the heat insulating pipe α from the second collective flow path A2 on one end side by the collective flow path partitioning section 310 in the branch box 150 on one end side. It is configured independently by dividing it into the first collecting channel A1 on the end side. In this example, a composite cooling mechanism 200 is provided in each of the main circuit and the sub circuit. As an actual configuration around the collective flow path partition section, each cable core penetrates the collective flow path partition section 310, between the inner peripheral surface of the collective flow path partition section 310 and the outer peripheral surface of the cable core, and the collective flow The space between the outer peripheral surface of the road partition 310 and the inner peripheral surface of the heat insulation pipe α is sealed in a watertight manner with respect to the liquid refrigerant.

  In FIG. 5, for convenience of explanation, the first supply pipe Cg1 and the second supply pipe Cg2 are illustrated only for the route A (Af, At), and the route B (Bf, Bt) and the route C (Cf, Ct). ) Is shown divided in the middle. However, in practice, the first supply pipe Cg1 and the second supply pipe Cg2 of a total of three routes including the route B and the route C are connected to the distal end side of each branch cable portion 100B. In the case of this example, since there are three routes in each of the first supply pipe Cg1 and the second supply pipe Cg2, the number of pumps 220 that supply the refrigerant from the cooling mechanism 200 is preferably six in total. Thereby, it is easy to adjust the flow path of the refrigerant for each branch cable portion.

According to the system having the above-described configuration, not only the space between the heat insulating pipe α (β) and the core but also the space inside the former is used as a refrigerant flow path to form two circulation paths. At that time, one end side of the collective flow path is separated as the second collective flow path A2 and the other end side is separated as the first collective flow path A1 by the flow path partitioning section 310. Since the outer channel OC ₁ in the other end of the branch cable section 100B is mainly individual channel, the outer channel OC ₂ in one end of the branch cable section 100B is an auxiliary individual passage, a plurality The refrigerant is allowed to flow from the individual flow path to the collective flow path, but the refrigerant is not diverted from the collective flow path to the plurality of individual flow paths. Thereby, it is possible to suppress the cooling degree of each core in each branch cable portion 110B from varying. In particular, since the pump 220 is used individually corresponding to each core, it is easy to suppress the imbalance in the refrigerant flow rate in each individual flow path.

<Embodiment 6>
Next, in the system according to the first to third embodiments, a terminal structure suitable for introducing a refrigerant from the cooling mechanism to the individual flow path in the branch cable portion will be described with reference to FIG. This terminal structure 1A is formed by connecting the superconducting cable 100 and the normal conducting lead 2, and covering the outer periphery of the connecting portion with the heat insulating structure 3A extending from the heat insulating tube α of the cable 100 to the normal conducting lead 2. .

  The superconducting cable 100 that forms the terminal structure 1A is used in a strand wire structure former that is insulated from the strands, and the space between the heat insulating tube α and the core group is used as a refrigerant flow path. In FIG. 6, for convenience of explanation, since the tip of the core 110 is stripped, only the former 111 and the superconducting conductor layer 112 are shown, and the other components are omitted. The configuration is the same as that of the ten cable cores 110 (this also applies to Embodiments 7 to 9 described later).

  The heat insulating structure 3A includes a cable-side heat insulating container 31 disposed on the superconducting cable side of the terminal structure (which may be simply referred to as a cable side (direction) in the lower side of FIG. 6) and a normal conductive lead side (see FIG. 6). A lead-side heat insulating container 32 disposed on the lead side (direction), and an insulating member 33 disposed between the two heat insulating containers 31 and 32.

  The cable-side heat insulation container 31 is a vacuum double structure container attached to the end of the heat insulation pipe α of the superconducting cable. In this example, since the stress cone is formed in the insulating member 33 described later, the cable-side heat insulating container 31 is configured by a cylindrical body having an inner peripheral shape corresponding to the outer peripheral shape of the insulating member 33. The cable-side heat insulation container 31 is formed with a refrigerant passage 31h that communicates with the space between the heat insulation pipe α and the core 110 and the external space of the heat insulation container 31.

  With respect to such a cable-side heat insulating container 31, the end portion of the core 110 protrudes in the lead direction. That is, the connecting portion between the core 110 and the normal conducting lead 2 also protrudes outward in the lead direction from the cable-side heat insulating container 31. In this example, the end of the core 110 protrudes further in the lead direction than an insulating member 33 described later.

  The dimension in the radial direction of the cable-side heat insulation container 31 is larger than that of the heat insulation pipe α. This is because most of the insulating member 33 described later is accommodated in the cable-side heat insulating container 31. However, the protruding amount in the radial direction of the cable-side heat insulating container 31 may be smaller than the conventional one. This is because the end portion of the core 110 protrudes to the outside of the cable-side heat insulating container 31 or the insulating member 33, so that the cable insulating layer 113 exists in a portion of the core 110 that is covered with the cable-side heat insulating container 31. That is, since the cable-side heat insulating container 31 can be maintained at the ground potential without taking a distance from the core 110 in the radial direction due to the presence of the cable insulating layer 113, the dimension in the radial direction can be made smaller than before.

  The lead side heat insulating container 32 is a vacuum double structure container attached to the end of the normal conducting lead 2. In this example, the lead-side heat insulating container 32 is formed of a tubular body having an inner diameter on the REIT side smaller than an inner diameter on the cable side and a uniform outer diameter. Since the lead-side heat insulating container 32 is attached to the end of the normal conducting lead 2, it has a high potential. The end of the lead-side heat insulating container 32 on the side with the larger inner diameter is housed in the cable-side heat insulating container 31, and is overlapped with the lead-side end of the cable-side heat insulating container 31 in the longitudinal direction of the core 110. . The overlap length is determined by the allowable amount of intrusion heat. At a low voltage, the insulating member 33 is thin and the overlap length can be shortened. On the other hand, it is desirable to increase the overlap length as the voltage increases.

  The insulating member 33 is interposed in an overlap portion between the cable-side heat insulation container 31 and the lead-side heat insulation container 32, and insulates between the cable-side heat insulation container 31 connected to the ground and the lead-side heat insulation container 32 in the high voltage region. For the insulating member 33, for example, a material having excellent withstand voltage characteristics such as an epoxy molded member used for a terminal portion of an existing normal conducting cable or the like can be used. In this example, the insulating member 33 is a stress cone.

  The insulating member 33 protrudes not only in the overlap portion but also in both the lead direction and the cable direction of the overlap portion. This is because the necessary creepage distance is provided between the cable-side heat insulating container 31 and the lead-side heat insulating container 32 to ensure insulation between the two containers 31 and 32. Further, in this example, the portion of the insulating member 33 that protrudes to the inner peripheral side is flush with the inner peripheral surface of the insulating member 33 and the lead-side heat insulating container 32, and the refrigerant flow is disturbed in the portion. That is restrained.

  Further, in this example, a partition member 44 is provided between the heat insulating structure 3A and the cable core 110 via a spacer 45. The partition member 44 is a cylindrical member that covers the outer periphery of a predetermined length portion of the cable core 110, has a uniform outer diameter and inner diameter over the entire length, and has a flange portion on the cable side in the longitudinal direction (lower side in the drawing). Have. The flange portion is connected to the inner peripheral surface on the cable side of the cable-side heat insulating container 31 with respect to the core-side opening of the refrigerant passage 31h. On the other hand, the end portion of the partition member 44 opposite to the flange portion is disposed as a free end in the space between the lead-side heat insulating container 32 and the core 110. By this partition member 44, a space on the outer peripheral side and a space on the inner peripheral side sandwiching the partition member 44 are partitioned. In this example, the refrigerant passage 31h provided in the cable-side heat insulating container 31 is connected to the cable side of the outer peripheral space, and further connected to the inner peripheral space on the lead side of the outer peripheral space.

  The spacer 45 that holds the partition member 44 between the heat insulating structure 3A and the cable core 110 is interposed between the partition member 44 and the core 110 and between the partition member 110 and the heat insulating structure 3A. The spacers 45 are provided at substantially equal intervals in the circumferential direction on the inner periphery or outer periphery of the partition member 44.

  In such a terminal structure 1A, the refrigerant is introduced from the refrigerant passage 31h provided in the cable-side heat insulating container 31, flows in the space on the outer peripheral side of the partition member 44 toward the lead side, and the lead-side end portion of the partition member 44 Between the heat insulation pipe α and the core 110, and is distributed to the space on the inner peripheral side of the partition member 44. Therefore, if this terminal structure 1A is used as a terminal portion of the superconducting cable of Embodiments 1 to 3, the refrigerant pumped from the cooling mechanism 200 (FIGS. 1 to 3) is supplied to the heat insulating tube α and the core 110 via the terminal. Can be supplied to the space between. When the refrigerant is discharged from the terminal portion of the superconducting cable to the cooling mechanism side, the flow direction of the refrigerant may be reversed using the same terminal structure 1A.

<Embodiment 7>
Next, in the system according to Embodiments 4 and 5, a terminal structure suitable for the distal end portion of the branch cable portion on the other end side (the right side in FIGS. 4 and 5) will be described based on FIG.

  Similarly to the sixth embodiment, the terminal structure 1B connects the core 110 exposed from the heat insulating tube 120 (α) of the superconducting cable 100 to the normal conductive lead 2, and the normal conductive lead 2 and the end of the heat insulating tube 120 are connected. Is covered with a heat insulating structure 3B having a cable side heat insulating container 31, a lead side heat insulating container 32, and an insulating member 33. Both the heat insulating containers 31 and 32 partially overlap each other, an insulating member 33 is interposed at the overlapped portion, and the inner peripheral surface of the heat insulating structure 3B is configured by a cylindrical surface. This is the same as in the sixth embodiment.

  However, the superconducting cable 100 used in this example includes a core 110 using a hollow pipe former, and not only the space between the heat insulating tube α and the core 110 but also the space in the former is used as a refrigerant flow path. To do. At the end of the core 110, a communication hole 110h is formed which communicates the space in the former with the outer space of the core. The insulating member 33 is not a stress cone, but is a cylindrical member. More specifically, the insulating member 33 has an inner diameter at the end on the lead side larger than the inner diameter on the cable side and has a step on the inner peripheral surface, and both end sides sandwiching the step are formed to have a uniform thickness. ing. Furthermore, the cable side heat insulating container 31 is not formed with the refrigerant passage 31h shown in the sixth embodiment, and the space surrounded by the normal conducting lead 2, the heat insulating structure 3B, the heat insulating tube α, and the core 110 is not formed. It is sealed against the outside of the heat insulating structure 3B.

  In such a terminal structure 1B, the refrigerant that has flowed toward the lead side through the space in the former flows from the inside of the former to the outer space of the core 110 through the communication hole 110h at the tip of the core 110. Is done. Then, it is folded back to the cable side and distributed in the space between the heat insulating tube α and the core 110. Therefore, if such a terminal structure 1B is used for the terminal on the other end side (right side of the drawings) of FIGS. 4 and 5, the refrigerant can be circulated so as to be folded at the tip in each branch cable portion. In this terminal structure 1B, it is a matter of course that the refrigerant can be circulated from the outer space of the core 110 to the space inside the former 111 by reversing the flow direction of the refrigerant.

<Eighth embodiment>
Next, in the system according to the second and third embodiments, a configuration of a connection unit suitable for configuring the refrigerant flow path of the branch cable portion will be described with reference to FIG. In this example, the connection unit 400 on the left side in FIGS. 2 and 3 is described as an example. The superconducting cable 100X is on the right side and the superconducting cable 100Y is on the left side with the middle part of the unit 400 as a boundary.

  In this example, each core 110 of the superconducting cable and each core 110u, 110v, 110w in the branch cable portion 110B are made independent, and both the cores 110, 110u, 110v, 110w are connected via the connection unit 400. Adopted. In FIG. 8, the right side is the superconducting cable side, the left side is the branch cable portion 100B side, and the upper one of the three branch cable portions 110B has a refrigerant flow path only between the core 110u and the heat insulating tube β. The two cores 110v and 110w in the middle part and the lower part further use the interior of the former 111 as a refrigerant flow path.

  The connection unit 400 includes, in order from the inside, a conductive block 410, an insulating portion 430, and a heat insulating container 440, a superconducting cable insertion port on one end side, and each core 110u, 110v of the branch cable portion 100B on the other end side. 110w outlet is provided. That is, the right side of FIG. 8 has one insertion port 401 into which the cores 110 of the superconducting cable are collectively inserted, and three cores 110u, 110v, 110w of the branch cable unit 100B are individually inserted on the left side. An insertion port 402 is provided.

  The conductive block 410 is a conductive member for electrically connecting the respective superconducting conductor layers of the core 110 of the superconducting cable and the 100B cores 110u, 110v, 110w of the branch cable portion for each phase. Both ends of the conductive block 410 are provided with connection concave portions 412 directed to the respective insertion ports 401 and 402, and each connection concave portion 412 has a connection convex portion 130 obtained by terminating the end portion of the superconducting conductor layer 112 to be connected. Plugged in. The connection convex portion 130 is made of a conductive material such as copper, and is inserted into the connection concave portion 412 so that they are engaged with each other and the conductor to be connected is reliably connected to the conductive block 410. Specific examples of the connection concave portion 412 and the connection convex portion 130 include a tulip contact and a multi-contact that are generally used for conductor connection between normal conducting cables. As a material of the conductive block 410, a metal having high conductivity at a low temperature, for example, copper, a copper alloy, aluminum, or an aluminum alloy can be suitably used. In this example, three conductive blocks 410 made of solid copper are used.

  Furthermore, in this example, the inside of the front end side of each connection convex part 130 corresponding to a pair of cores 110v and 110w is connected so as to intersect with the vertical hole communicating with the inner flow path IC in the former 111. A horizontal hole 130h is provided. In addition, a through hole 432h is formed in a portion of the insulating portion 430 that is interposed between the conductive blocks 410 corresponding to the pair of cores 110v and 110w. When each connecting projection 130 is inserted into the connecting recess 412, the lateral holes 130h in the conductive block 410 are communicated with each other through the through holes 432h. Therefore, in the state where the connection convex portion 130 is inserted into the connection concave portion 412, the inner flow path IC in the former 111 in one of the cores 110v and 110w is connected to the other core 110v through the vertical hole, the horizontal hole 130h, and the through hole 432h. (110w) of the inner flow path IC in the former 111 is communicated.

  In this conductive block 410, connection concave portions 412 into which the connection convex portions 130 are inserted are opened at both ends, and portions other than the opening portions are covered with the insulating portion 430. The insulating portion 430 does not deteriorate with the temperature of the refrigerant, and a material suitable for an airtight structure can be preferably used. In this example, the insulating part 430 is made of a plastic material such as epoxy. The insulating portion 430 forms openings that connect to the respective insertion ports 401 and 402 in order to secure a insertion path from which the connection target reaches each connection recess 412.

  In addition, the insulating portion 430 is formed with a communication hole 434h that connects the openings into which the core 110u and the core 110v of the branch cable portion 100B are inserted. In a state where the connecting projections 130 of the core 110u and the core 110v are inserted into the conductive block 410, the outer flow paths OC corresponding to the core 110u and the core 110v are communicated with each other. That is, the insulating part 430 in the vicinity of the communication hole 434h corresponds to the individual flow path partition part 320 in FIG.

  Further, the insulating portion 430 is provided with a communication hole 436 h that is connected from one end side to the other end side of the connection unit 400. The communication hole 436h in this example communicates from the opening of the insulating portion 430 corresponding to the core 110w to the opening into which the connection convex portion 130 of the core 110 abutted against the core 110w is inserted. Therefore, in a state where the core 110w of the superconducting cable and the core 110w of the branch cable portion 110B are inserted into the connection recess 412 of the conductive block 410, the outer flow path OC of the core 110w and the first aggregate flow path A1 of the core 110 are communicated with each other. Will be.

  On the other hand, the outside of the insulating part 430 is surrounded by a heat insulating container 440. The heat insulating container 440 forms a heat insulating space on the outer periphery of the insulating part 430, and suppresses heat intrusion into the refrigerant in the vicinity of the opening of the insulating part 430. In this example, the heat insulating container 440 is disposed so as to overlap the outside of the insulating portion 430, and the closed space in the heat insulating container 440 is evacuated to form the heat insulating space. In this heat insulating space, a heat insulating material (not shown) such as super insulation may be arranged in order to suppress heat intrusion due to radiation. Of course, this heat insulating container 440 also has an opening where a connection object is inserted.

  As the material of the heat insulating container 440, a metal material having excellent airtightness can be suitably used. In this example, stainless steel is used.

  The outside of the heat insulating container 440 is covered with a corrosion prevention layer (not shown). The anticorrosion layer may be thin enough to protect from the external environment. This is because the heat insulating container 440 itself is at the ground potential by covering the conductive block 410 with the insulating portion 430.

  In order to connect each core 110 of the superconducting cable 100 and each core 110u, 110v, 110w of the branch cable unit 100B to such a connection unit 400, terminal processing is performed on the tip of each core 110, 110u, 110v, 110w. Do. For example, the former 111 exposed from the branch cable portion is connected to the connection convex portion 130 by compression or the like, and the superconducting conductor layer 112 and the connection convex portion 130 are electrically connected. The same terminal processing is performed on each core 110 of the superconducting cable. The heat insulating tube α is vacuum-processed after being cut and sealed at a predetermined position, for example.

  If the connection portion having such a structure is used, the refrigerant flowing through the outer flow path OC of the core 110u flows to the outer flow path OC corresponding to the core 110v via the communication hole 434h on the conductive block side of the core 110u. Is done. The refrigerant that has flowed through the outer flow path OC corresponding to the core 110v from the conductive block side toward the terminal portion side (left side in FIG. 8) is folded back at the terminal portion and formed in the former 111 of the core 110v. To reach the connection convex portion 130. Further, the refrigerant is formed in the former 111 of the core 110w through the vertical hole, the horizontal hole 130h, the communication hole 432h of the insulating part 430, the horizontal hole 130h of the core 110w, and the vertical hole. Introduced into the inner channel IC. Subsequently, the refrigerant flows through the inner flow path IC of the core 110w from the conductive block 410 side toward the terminal portion side, and is turned back at the terminal portion to pass through the outer flow path OC corresponding to the core 110w to the conductive block 410 side again. Refrigerant is distributed. Then, the refrigerant flows from the outer channel OC of the core 110w to the first collecting channel A1 of the superconducting cable through the communication hole 436h.

  If such a connection unit 400 is used, a configuration from the connection unit 400 to the branch cable portion 100B in FIGS. 2 and 3 can be easily constructed. At that time, by inserting the cable cores 110, 110u, 110v, 110w subjected to terminal processing into the connection unit 400, communication between the refrigerant channels of the superconducting cable and the branch cable unit 100B, and between the cores of the superconducting cable and the branch cable unit 100B The electrical connection can be easily realized.

<Ninth Embodiment>
Next, in the system according to the fifth embodiment, a terminal structure suitable for introducing a refrigerant into each of the inner flow path and the outer flow path from the branch cable portion on one end side (left side in FIG. 5) based on FIG. explain. The following description is mainly about differences from the terminal structure described in the seventh embodiment.

The terminal structure 1C is similar to the terminal structure of the seventh embodiment, but the two refrigerant passages 31h ₁ and 31h ₂ are formed in the cable-side heat insulating container 31, and the cable-side heat insulating container 31 and the core are formed. The difference is that a partition plate 46 is interposed between the two and 110. The partition plate 46 is disposed on the entire circumference of the core 110 in the outer circumferential direction, and partitions the space between the heat insulating tube α and the heat insulating structure 3C and the core 110 into the lead side and the cable side. One of the two refrigerant passages 31h ₁ and 31h ₂ opens into the space on the lead side of the partition plate 46, and the other opens into the space on the cable side.

Such a terminal structure 1C is preferably used for the terminal on one end side (left side in the figure) of FIG. 5 to supply the refrigerant from the cooling mechanism into the former and also supply the refrigerant to the outside of the core 110. Available. That is, the refrigerant supplied from _one refrigerant passage 31h1 is introduced into the space on the lead side of the partition plate 46 in the space between the heat insulating structure 3C and the core 110, and the core end communication hole 110h. Is circulated through the inner flow path in the former. Further, the refrigerant supplied from the other refrigerant passage 31h _2, of the space between the insulation assembly 3C and the core 110, the partition plate 46 is introduced into the space of the cable, the heat insulating tube α and the core 110 Is circulated in the outer flow path between.

  In addition, this invention is not necessarily limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably. For example, when the superconducting cable is for alternating current and includes a cable shielding layer, it is preferable to short-circuit each cable shielding layer within the collective flow path or the individual flow path.

  The superconducting cable system of the present invention can be suitably used for forming an AC or DC power transmission network using a low-temperature insulated superconducting cable.

100,100X, 100Y superconducting cable
110,100u, 100v, 100w Cable core 110h Communication hole
111 Former 112 Superconducting conductor layer
113 Cable insulation layer 114 Cable shielding layer 115 Protective layer
120, α, β Insulated pipe 121 Inner pipe 122 Outer pipe 123 Anticorrosion layer
100A Focusing cable part 100B Branch cable part
100E terminal
AC collecting channel A1 First collecting channel A2 Second collecting channel
BC Individual flow path
B1, B1u, B1v, B1w 1st individual outbound route
B2, B2u, B2v, B2w Second individual outbound route
Bg Individual outbound route Br Individual returning route
CC Return C1 First Return C2 Second Return
Cg, Cg1, Cg2 supply pipe Cr, Cr1, Cr2 discharge pipe
IC, IC ₁ , IC ₂ inner flow path OC, OC ₁ , OC ₂ outer flow path
T1 First channel transition part T2 Second channel transition part
130 Connection convex part 130h Side hole
150 branch box
200 Cooling mechanism 210 Reservoir tank 220 Pump 230 Refrigerator
300 Channel partition 310 Collective channel partition 320 Individual channel partition
1A, 1B, 1C terminal structure
2 Normal conducting lead
3A, 3B, 3C thermal insulation structure
31 Cable side insulation container 31h, 31h ₁ , 31h ₂ Refrigerant passage
32 Lead-side insulated container
33 Insulation material
44 Partition member 45 Spacer 46 Partition plate
400 connection units
401, 402 outlet
410 Conductive block
412 Connection recess
430 Insulation part 432h Through hole 434h, 436h Communication hole 440 Thermal insulation container
Sc, S1, S2, S3, S4, S5 Superconducting cable system

Claims (8)

In the middle part of the superconducting cable line, a converging cable part in which a plurality of cable cores are collectively stored in one heat insulating tube α,
At both ends of the superconducting cable line, branch cable portions that are branched into the respective cable cores and housed in individual heat insulating tubes β,
A superconducting cable system comprising: a cooling mechanism that cools a refrigerant that maintains the cable core at a cryogenic temperature and circulates the refrigerant in a circulation path that passes through the focusing cable portion and the branch cable portion;
The circuit is
A collecting channel formed in the converging cable portion;
Individual flow paths formed in each branch cable part,
A flow path transition section that allows the refrigerant to flow from at least one of the individual flow paths to the collective flow path;
A superconducting cable system comprising: a flow path partitioning section that prevents the refrigerant from being diverted from the collective flow path to a plurality of individual flow paths. The circulation path includes a first circulation path and a second circulation path that are independent from each other,
The first circuit is
A first individual flow path provided at one end of the superconducting cable line;
A first collecting channel connected to the first individual channel via a first channel transition part;
The second circuit is
A second individual flow path provided on the other end of the superconducting cable line;
Having a second collecting channel connected to the second individual channel via a second channel transition part,
2. The superconducting cable system according to claim 1, wherein the flow path partitioning section includes a collective flow path partitioning section that partitions the first collective flow path and the second collective flow path.   At least one of the first individual flow path and the second individual flow path is configured in parallel for each cable core, and any of the parallel individual flow paths is the first flow path transition portion and the second flow path. 3. The superconducting cable system according to claim 2, wherein the superconducting cable system is connected to at least one of the first collecting channel and the second collecting channel via at least one of the transition portions. At least one of the first individual flow path and the second individual flow path is configured in a series along all cable cores, and only one of the individual flow paths along each cable core has the flow path transition portion. Connected to at least one of the first collecting channel and the second collecting channel via
3. The flow path partitioning section has an individual flow path partition section that partitions the remaining individual flow paths excluding one individual flow path connected to the collective flow path from the collective flow path. Superconducting cable system. The circuit is composed of a single circuit,
The individual flow path is
One end side individual flow path formed in series along all cable cores on one end side of the superconducting cable line,
The other end side individual flow path formed in series along all the cable cores on the other end side of the superconducting cable line,
2. The superconducting cable system according to claim 1, wherein the collecting channel is configured to connect the one end side individual channel and the other end side individual channel.   The first individual flow path and the second individual flow path are formed in a space between the heat insulation pipe β and each core, and the first collective flow path and the second collective flow path are between the heat insulation pipe α and each core. The superconducting cable system according to any one of claims 3 to 5, wherein the superconducting cable system is formed in a space. The superconducting cable line is
An outer flow path through which a refrigerant flows in a space between the heat insulation pipe α and the heat insulation pipe β and each cable core;
An inner flow path through which refrigerant flows in the internal space of the hollow former provided in each cable core,
The circulation path is a cooling mechanism, an outer channel in the branch cable part on one end side of the superconducting cable line, an inner channel in the branch cable part on one end side of the superconducting cable line, an inner channel in each core in the focusing cable part, Single flow that is circulated in the order of the inner flow path in the branch cable part on the other end side of the superconducting cable line, the outer flow path in the branch cable part on the other end side of the superconducting cable line, the outer flow path in the focusing cable part, and the cooling mechanism Consisting of
2. The superconducting cable system according to claim 1, wherein the flow path partitioning section partitions an outer flow path in the branch cable section on one end side of the superconducting cable line and an outer flow path in the focusing cable section. The superconducting cable line is
An outer flow path through which a refrigerant flows in a space between the heat insulation pipe α and the heat insulation pipe β and each cable core;
An inner flow path through which refrigerant flows in the internal space of the hollow former provided in each cable core,
The circuit includes a main circuit and a sub circuit independent from each other,
The main circulation path includes a cooling mechanism, an inner flow path in the branch cable portion on one end of the superconducting cable line, an inner flow path in each core in the focusing cable portion, and an inner flow in the branch cable portion on the other end side of the superconducting cable line. Circulated in the order of the path, the outer flow path in the branch cable part on the other end side of the superconducting cable line, the outer flow path in the focusing cable part, and the cooling mechanism,
The secondary circulation path is circulated in the order of the cooling mechanism, the outer flow path in the branch cable part on one end side of the superconducting cable line, the outer flow path in the focusing cable part, and the cooling mechanism.
2. The superconducting cable system according to claim 1, wherein the flow path partition section partitions outer flow paths in the converging cable section of the main circulation path and the sub circulation path.

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