JP2014146585A

JP2014146585A - Superconductive cable and superconductive cable rail track

Info

Publication number: JP2014146585A
Application number: JP2013016179A
Authority: JP
Inventors: Masayuki Hirose; 正幸廣瀬; Hiroyasu Yumura; 洋康湯村
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 2013-01-30
Filing date: 2013-01-30
Publication date: 2014-08-14

Abstract

PROBLEM TO BE SOLVED: To provide a superconductive cable that can make the length of a cooling section longer than before.SOLUTION: A superconductive cable 1 includes: a cable unit 90; an inner coolant 20C; and an outer coolant 30C. The cable unit 90 includes: a cable internal member 10; an internal member housing tube 20 that houses the cable internal member 10 in the inside; and an outer insulating tube 30 that houses the internal member housing tube 20 in the inside. The internal member housing tube 20 is set longer than the outer insulating tube 30. The inner coolant 20C is circulated in the inside of the internal member housing tube 20, and the outer coolant 30C is circulated in the inside of the outer insulating tube 30 and in the outside of the internal member housing tube 20. The intruded heat from outside environment via the outer insulating tube 30 is treated by the circulation of the outer coolant 30C.

Description

本発明は、超電導導体を有するケーブル内部部材を備える超電導ケーブル、およびその超電導ケーブルを備える超電導ケーブル線路に関する。 The present invention relates to a superconducting cable including a cable internal member having a superconducting conductor, and a superconducting cable line including the superconducting cable.

超電導導体を有するケーブル内部部材を備える超電導ケーブルが知られている。特許文献１の超電導ケーブルは、フォーマの外周に少なくとも超電導導体と電気絶縁層を設けたケーブル内部部材を断熱管の内部に収納し、その断熱管の内部に液体冷媒を循環させる構成（いわゆる低温絶縁型の構成）を備える。一方、特許文献２の超電導ケーブルは、フォーマの外周に超電導導体を備えるケーブル内部部材を、電気絶縁層を外周に設けた断熱管の内部に収納し、その断熱管の内部に液体冷媒を循環させる構成（いわゆる常温絶縁型の構成）を備える。いずれの構成においても、ケーブル内部部材を収納する断熱管内に液体冷媒を循環冷却させることで、外部環境から断熱管内への侵入熱を処理し、ケーブル内部部材の超電導導体を極低温に維持することができる。なお、交流送電を行なう超電導ケーブルでは、交流損失によって超電導導体自身が発熱するため、侵入熱に加えて超電導導体の発生熱を処理する必要があるのに対し、直流送電を行なう超電導ケーブルでは、外部環境からの侵入熱を処理することで超電導導体を極低温に維持することができる。 A superconducting cable including a cable inner member having a superconducting conductor is known. The superconducting cable of Patent Document 1 has a configuration in which a cable internal member having at least a superconducting conductor and an electrical insulating layer provided on the outer periphery of a former is housed in a heat insulating tube, and a liquid refrigerant is circulated inside the heat insulating tube (so-called low temperature insulation). Mold configuration). On the other hand, in the superconducting cable of Patent Document 2, a cable inner member having a superconducting conductor on the outer periphery of the former is housed in a heat insulating pipe having an electric insulating layer provided on the outer periphery, and a liquid refrigerant is circulated inside the heat insulating pipe. It has a configuration (so-called room temperature insulation type configuration). In any configuration, by circulating and cooling the liquid refrigerant in the heat insulation pipe that houses the cable internal member, the intrusion heat from the external environment into the heat insulation pipe is processed, and the superconducting conductor of the cable internal member is maintained at a very low temperature. Can do. In a superconducting cable that performs AC power transmission, the superconducting conductor itself generates heat due to AC loss, so it is necessary to handle the heat generated by the superconducting conductor in addition to intrusion heat. The superconducting conductor can be kept at a very low temperature by treating the intrusion heat from the environment.

上記構成における液体冷媒は、循環路中で気化しない温度・圧力の条件（つまり、循環路中で液体冷媒の気化が生じることは、この条件を外れていることを意味する）の下、所定の流量で循環されている。気化要因である液体冷媒の温度は、直流送電にあっては侵入熱、交流送電にあっては侵入熱に加えて超電導導体の発生熱によって上昇する。その温度上昇が所定の範囲内になるように液体冷媒の流量が設定され、温度が上昇した液体冷媒は冷却システムにより冷却されることで、循環路中の液体冷媒が気化しない状態に維持される。なお、許容温度とは、超電導導体の臨界温度未満の温度であって、超電導導体が所定の電流容量（Ａ）を満たすことができる温度のことである。 The liquid refrigerant in the above configuration has a predetermined temperature / pressure condition that does not vaporize in the circulation path (that is, the occurrence of vaporization of the liquid refrigerant in the circulation path means that this condition is not met). Circulated at a flow rate. The temperature of the liquid refrigerant, which is a vaporization factor, rises due to heat generated by the superconducting conductor in addition to intrusion heat in DC transmission and intrusion heat in AC transmission. The flow rate of the liquid refrigerant is set so that the temperature rise is within a predetermined range, and the liquid refrigerant whose temperature has risen is cooled by the cooling system, so that the liquid refrigerant in the circulation path is maintained in a state that does not vaporize. . The allowable temperature is a temperature that is lower than the critical temperature of the superconducting conductor and can satisfy the predetermined current capacity (A).

特開２０１１−２２６５２６号公報JP 2011-226526 A 特開２０１２−１７４４０３号公報JP 2012-174403 A

近年、超電導ケーブルの冷却区間長を長くすることが望まれている。例えば、長距離トンネルなど、超電導ケーブルの冷却システムを設置するスペースの確保が難しい環境に、超電導ケーブルを布設する場合が想定されるからである。 In recent years, it has been desired to increase the cooling section length of a superconducting cable. For example, it is assumed that the superconducting cable is laid in an environment where it is difficult to secure a space for installing the cooling system for the superconducting cable, such as a long-distance tunnel.

ここで、超電導ケーブルの冷却区間長が長くなると、ケーブル内部部材を冷却する液体冷媒の圧力損失が大きくなるため、超電導ケーブルに何らかの対策を施すことが求められる。例えば、液体冷媒の圧力損失を考慮して液体冷媒を高圧で循環させることが考えられる。その場合、液体冷媒の圧力に耐え得るように断熱管を耐高圧設計とする必要がある。しかし、断熱管の強度の向上にも限界があるため、断熱管の強度による超電導ケーブルの長尺化には限界がある。また、別の対策として、断熱管の径を大きくする、即ち液体冷媒の流路断面積を大きくして、液体冷媒の圧力損失が高くなることを抑制することが考えられる。しかし、超電導ケーブルの設置スペースの問題、大径化した断熱管の強度の問題などがあるため、断熱管の径を大きくすることにも限界があり、やはり超電導ケーブルの長尺化は難しい。そのため、全く新しい構造の超電導ケーブルの開発が望まれている。 Here, when the cooling section length of the superconducting cable becomes longer, the pressure loss of the liquid refrigerant that cools the cable internal member becomes larger. Therefore, it is required to take some measures against the superconducting cable. For example, it is conceivable to circulate the liquid refrigerant at a high pressure in consideration of the pressure loss of the liquid refrigerant. In that case, it is necessary to make the heat insulating tube have a high pressure resistant design so as to withstand the pressure of the liquid refrigerant. However, since there is a limit to improving the strength of the heat insulating tube, there is a limit to lengthening the superconducting cable due to the strength of the heat insulating tube. As another countermeasure, it is conceivable to increase the diameter of the heat insulating tube, that is, to increase the flow passage cross-sectional area of the liquid refrigerant, thereby suppressing an increase in the pressure loss of the liquid refrigerant. However, since there are problems with the space for installing the superconducting cable and the strength of the heat insulating pipe having a large diameter, there is a limit to increasing the diameter of the heat insulating pipe, and it is difficult to lengthen the superconducting cable. Therefore, development of a superconducting cable with a completely new structure is desired.

本発明は上記事情に鑑みてなされたものであり、その目的の一つは、従来よりも冷却区間長を長くすることができる超電導ケーブル、およびその超電導ケーブルを用いた超電導ケーブル線路を提供することにある。 The present invention has been made in view of the above circumstances, and one of its purposes is to provide a superconducting cable capable of making the cooling section length longer than before, and a superconducting cable line using the superconducting cable. It is in.

本発明の超電導ケーブルは、超電導導体を有するケーブル内部部材を備える超電導ケーブルであって、ケーブル部と、内側冷媒と、外側冷媒と、を備える。ケーブル部は、ケーブル内部部材と、ケーブル内部部材を内部に収納する内部部材収納管と、その内部部材収納管を内部に収納する外側断熱管と、を備える。内側冷媒は、内部部材収納管の内部に循環され、ケーブル内部部材に備わる超電導導体を極低温に冷却する。外側冷媒は、外側断熱管の内部で、かつ内部部材収納管の外側に循環され、内部部材収納管の温度上昇を抑制する。内部部材収納管は、外側断熱管よりも長く、それによってケーブル部の長手方向に、内部部材収納管に外側断熱管が重複する重複領域（即ち、内側冷媒に外側冷媒が重複する領域）と、内部部材収納管に外側断熱管が重複しない非重複領域（即ち、内側冷媒に外側冷媒が重複しない領域）と、が形成されている。 The superconducting cable of the present invention is a superconducting cable including a cable inner member having a superconducting conductor, and includes a cable portion, an inner refrigerant, and an outer refrigerant. The cable portion includes a cable internal member, an internal member storage tube that stores the cable internal member therein, and an outer heat insulating tube that stores the internal member storage tube therein. The inner refrigerant is circulated inside the inner member storage pipe and cools the superconducting conductor provided in the cable inner member to a cryogenic temperature. The outer refrigerant is circulated inside the outer heat insulating tube and outside the inner member housing tube, and suppresses the temperature rise of the inner member housing tube. The inner member storage tube is longer than the outer heat insulation tube, thereby overlapping in the longitudinal direction of the cable portion, the overlapping region where the outer heat insulation tube overlaps the inner member storage tube (that is, the region where the outer refrigerant overlaps the inner refrigerant), A non-overlapping region where the outer heat insulating tube does not overlap with the inner member storage tube (that is, a region where the outer refrigerant does not overlap with the inner refrigerant) is formed.

上記本発明の超電導ケーブルは、ケーブル内部部材よりも外側に内側冷媒の流路と外側冷媒の流路が形成された構成、即ちケーブル内部部材よりも外側に二重に液体冷媒の流路が形成された二重流路構造を備えている。これに対して、従来の超電導ケーブルには、ケーブル内部部材よりも外側に一重の液体冷媒の流路が形成された一重流路構造しかない。なお、従来の超電導ケーブルとして、ケーブル内部部材の中空フォーマの内側と、ケーブル内部部材の外側とに冷媒流路を形成したものはあるが、その場合もケーブル内部部材の外側には一重の液体冷媒の流路が形成されるのみであり、この構造は本明細書では一重流路構造として扱う。 The superconducting cable of the present invention has a configuration in which the flow path of the inner refrigerant and the flow path of the outer refrigerant are formed outside the cable internal member, that is, the liquid refrigerant flow path is formed double outside the cable internal member. Provided with a double channel structure. On the other hand, the conventional superconducting cable has only a single flow path structure in which a single liquid refrigerant flow path is formed outside the cable internal member. There is a conventional superconducting cable in which a refrigerant flow path is formed inside the hollow former of the cable internal member and outside of the cable internal member. In this case, a single liquid refrigerant is provided outside the cable internal member. This flow path is formed as a single flow path structure in the present specification.

本発明の超電導ケーブルでは、ケーブル内部部材を極低温に維持する内側冷媒と、外部環境からの侵入熱を処理する外側冷媒と、を分け、かつ内側冷媒の流路長を外側冷媒の流路長よりも長くした二重流路構造を採用している。そうすることで、本発明の超電導ケーブルの冷却区間長を、従来の超電導ケーブル構造（即ちケーブル内部部材の外側に一重の液体冷媒の流路が形成される一重流路構造の超電導ケーブル）よりも長くできる。仮に、基準となる一重流路構造の超電導ケーブルの冷却区間長を『１』とした場合、流路断面積を２倍とした一重流路構造の超電導ケーブルの冷却区間長は『約１．４』まで延ばすことが可能であるのに対して、本発明の二重流路構造を有する超電導ケーブルの冷却区間長は『約１．６』まで延ばすことが可能である。なお、本発明の超電導ケーブルにおける冷却区間長とは、超電導導体を有するケーブル内部部材に接触する内側冷媒の流路長のことである。 In the superconducting cable of the present invention, the inner refrigerant that maintains the cable inner member at a cryogenic temperature and the outer refrigerant that processes intrusion heat from the external environment are separated, and the flow length of the inner refrigerant is set to the flow length of the outer refrigerant. A longer double channel structure is adopted. By doing so, the cooling section length of the superconducting cable of the present invention is made longer than that of the conventional superconducting cable structure (that is, a superconducting cable having a single channel structure in which a single liquid refrigerant channel is formed outside the cable internal member). Can be long. Assuming that the cooling section length of the superconducting cable having a single-channel structure as a reference is “1”, the cooling section length of the superconducting cable having a single-channel structure in which the channel cross-sectional area is doubled is “about 1.4. In contrast, the cooling section length of the superconducting cable having the double flow path structure of the present invention can be extended to “about 1.6”. The cooling section length in the superconducting cable of the present invention is the flow path length of the inner refrigerant that contacts the cable internal member having the superconducting conductor.

本発明の超電導ケーブルとして、内部部材収納管が、少なくとも第一分割管と、その第一分割管と異なる構造の第二分割管と、を組み合わせてなる形態を挙げることができる。その場合、外側断熱管の内部に、外側断熱管とほぼ同尺の第一分割管が収納され、重複領域と非重複領域とのほぼ境界位置で、第一分割管と第二分割管とが接続される。 Examples of the superconducting cable of the present invention include a form in which the internal member housing pipe is a combination of at least the first split pipe and the second split pipe having a structure different from that of the first split pipe. In that case, a first divided pipe that is approximately the same size as the outer insulated pipe is accommodated inside the outer insulated pipe, and the first divided pipe and the second divided pipe are substantially at the boundary position between the overlapping region and the non-overlapping region. Connected.

上記構成によれば、後述する断熱構造と伝熱構造が混在した内部部材収納管を形成することが容易になる。 According to the said structure, it becomes easy to form the internal member storage pipe in which the heat insulation structure and heat-transfer structure which are mentioned later were mixed.

本発明の超電導ケーブルとして、外側断熱管の内部に、外側断熱管よりも長尺の内部部材収納管の一部が配置されている形態を挙げることができる。つまり、この構成では、内部部材収納管は、その全長にわたって断熱構造を有する部材である。 As the superconducting cable of the present invention, a form in which a part of the inner member housing tube that is longer than the outer heat insulating tube is disposed inside the outer heat insulating tube can be mentioned. That is, in this configuration, the inner member storage tube is a member having a heat insulating structure over its entire length.

上記構成によれば、外側断熱管の内部に内部部材収納管を配置するだけで、重複領域と非重複領域とを備える超電導ケーブルとすることができる。 According to the said structure, it can be set as the superconducting cable provided with an overlapping area | region and a non-overlapping area | region only by arrange | positioning an internal member accommodation pipe | tube inside an outer side heat insulation pipe | tube.

本発明の超電導ケーブルとして、内部部材収納管における少なくとも非重複領域に相当する部分が断熱構造を備える形態を挙げることができる。もちろん、内部部材収納管の全長にわたって断熱構造を備える形態でも良い。さらに、内部部材収納管の非重複領域が断熱構造、重複領域が伝熱構造である形態とすることもできる。 As the superconducting cable of the present invention, a form in which at least a portion corresponding to a non-overlapping region in the internal member housing pipe has a heat insulating structure can be mentioned. Of course, the form provided with a heat insulation structure over the full length of an internal member storage pipe may be sufficient. Furthermore, the non-overlapping area | region of an internal member storage pipe can also be set as the form which is a heat insulation structure and an overlapping area | region is a heat-transfer structure.

例えば、内部部材収納管が全長にわたって断熱構造を備える場合、内部部材収納管の内部の内側冷媒と、内部部材収納管の外部の外側冷媒と、の間の熱交換を抑制することができる。その場合、外側冷媒の影響によって内側冷媒の温度が変化することを抑制できる。この構成は、送電に伴うケーブル内部部材の発熱が無い直流送電に用いると良い。 For example, when the internal member storage tube has a heat insulating structure over its entire length, heat exchange between the internal refrigerant inside the internal member storage tube and the external refrigerant outside the internal member storage tube can be suppressed. In that case, the change of the temperature of the inner refrigerant due to the influence of the outer refrigerant can be suppressed. This configuration is preferably used for direct current power transmission without heat generation of the cable internal member accompanying power transmission.

一方、内部部材収納管における重複領域に相当する部分が伝熱構造である場合、その重複領域に相当する部分で内側冷媒と外側冷媒との間で熱交換を許容することができる。その場合、重複領域に相当する部分で内側冷媒の温度よりも外側冷媒の温度が低ければ、内側冷媒の温度上昇を抑制することができる。この構成は、送電に伴うケーブル内部部材の発熱が有る交流送電に用いると良い。ここで、内部部材収納管を、重複領域に配置される第一分割管と、非重複領域に配置される第二分割管と、に分ける構成であれば、重複領域を伝熱構造、非重複領域を断熱構造とすることが容易にできる。 On the other hand, when a portion corresponding to the overlapping region in the internal member storage pipe has a heat transfer structure, heat exchange can be allowed between the inner refrigerant and the outer refrigerant in the portion corresponding to the overlapping region. In that case, if the temperature of the outer refrigerant is lower than the temperature of the inner refrigerant in the portion corresponding to the overlapping region, the temperature rise of the inner refrigerant can be suppressed. This configuration is preferably used for AC power transmission in which the cable internal member generates heat due to power transmission. Here, if it is the structure which divides an internal member storage pipe into the 1st division pipe arrange | positioned in an overlap area, and the 2nd division pipe arrange | positioned in a non-overlap area, an overlap area will be a heat-transfer structure, non-overlap The region can be easily made into a heat insulating structure.

本発明の超電導ケーブルとして、内部部材収納管の断熱性能が変更可能に構成されている形態を挙げることができる。 Examples of the superconducting cable of the present invention include a configuration in which the heat insulation performance of the internal member housing pipe is changeable.

ケーブル内部部材を冷却する際、ケーブル内部部材の冷却状態にムラがあると、ケーブル内部部材の長手方向にケーブル内部部材の収縮差が生じるため、ケーブル内部部材に過大な張力が作用する恐れがある。これに対して、上記構成のように、内部部材収納管の断熱性能を変化させることができれば、ケーブル内部部材を冷却する際、ケーブル内部部材を長手方向にわたって極端な温度差が生じないように冷却することができ、ケーブル内部部材に過大な張力が作用することを抑制できる。ケーブル内部部材を長手方向にわたって冷却するには、ケーブル内部部材の冷却を開始するときにまず内部部材収納管の断熱性能を高くし、内部部材収納管と外側断熱管との間を冷却する。内部部材収納管の外周の温度が全長にわたって冷却された状態となったら、内部部材収納管の断熱性能を低くする。そうすることで、内部部材収納管の内部、即ちケーブル内部部材をその全長にわたってムラなく冷却することができる。 When the cable internal member is cooled, if there is unevenness in the cooling state of the cable internal member, a difference in contraction of the cable internal member occurs in the longitudinal direction of the cable internal member, so that excessive tension may act on the cable internal member. . On the other hand, if the heat insulation performance of the internal member storage tube can be changed as in the above configuration, when the cable internal member is cooled, the cable internal member is cooled so that an extreme temperature difference does not occur in the longitudinal direction. It is possible to suppress excessive tension from acting on the cable inner member. In order to cool the cable internal member in the longitudinal direction, when the cooling of the cable internal member is started, first, the heat insulation performance of the internal member storage tube is increased, and the space between the internal member storage tube and the outer heat insulation tube is cooled. When the temperature of the outer periphery of the internal member storage tube is cooled over the entire length, the heat insulation performance of the internal member storage tube is lowered. By doing so, the inside of the internal member housing tube, that is, the cable internal member can be cooled uniformly over its entire length.

本発明の超電導ケーブルは、直流送電に利用される形態であっても良いし、交流送電に利用される形態であっても良い。 The superconducting cable of the present invention may be used for DC power transmission or may be used for AC power transmission.

本発明の超電導ケーブルは特に、直流送電に利用される場合に超電導ケーブルの長尺化に寄与する。直流送電用途の超電導ケーブルにおいては交流損失がないため、超電導導体を適正な温度に維持するために処理すべき熱は外部環境からの侵入熱のみである。 The superconducting cable of the present invention contributes to the lengthening of the superconducting cable, particularly when used for direct current power transmission. Since there is no AC loss in a superconducting cable for direct current power transmission, the only heat that must be processed to maintain the superconducting conductor at an appropriate temperature is intrusion heat from the external environment.

一方、本発明の超電導ケーブル線路は、本発明の超電導ケーブルを少なくとも一部に備える。例えば、上記本発明の超電導ケーブル線路において、本発明の超電導ケーブルからなる第一超電導ケーブルと、内側流通管、および内側流通管が内部に収納される外側流通管を備えるリターン管と、が並列して設けられる箇所を有する形態を挙げることができる。その場合、第一超電導ケーブルの内部部材収納管と、リターン管の内側流通管と、を繋げ、第一超電導ケーブルの外側断熱管と、リターン管の外側流通管と、を繋げておくと良い。また例えば、上記本発明の超電導ケーブル線路において、本発明の超電導ケーブルからなる第二超電導ケーブルと第三超電導ケーブルとが並列して設けられる箇所を有する形態を挙げることができる。その場合、並列される第二超電導ケーブルと第三超電導ケーブルに備わる内部部材収納管同士、および外側断熱管同士を繋げておくと良い。 On the other hand, the superconducting cable line of the present invention includes at least a part of the superconducting cable of the present invention. For example, in the superconducting cable line of the present invention, the first superconducting cable made of the superconducting cable of the present invention and the return pipe including the inner flow pipe and the outer flow pipe in which the inner flow pipe is housed are arranged in parallel. The form which has the location provided in this way can be mentioned. In that case, it is preferable to connect the inner member storage pipe of the first superconducting cable and the inner circulation pipe of the return pipe, and to connect the outer heat insulating pipe of the first superconducting cable and the outer circulation pipe of the return pipe. Further, for example, in the superconducting cable line of the present invention, there can be mentioned a form having a location where the second superconducting cable and the third superconducting cable made of the superconducting cable of the present invention are provided in parallel. In that case, it is preferable to connect the inner member housing tubes and the outer heat insulating tubes provided in the second superconducting cable and the third superconducting cable arranged in parallel.

本発明の超電導ケーブル線路によれば、超電導ケーブル線路の布設経路において冷却システムを容易に設けることができない難布設区間（例えば長距離トンネルの内部など）がある場合にも超電導ケーブル線路を容易に構築することができる。本発明の超電導ケーブル線路に備わる超電導ケーブルのうち、冷却区間長が従来よりも長い本発明の超電導ケーブルを難布設区間に適用すれば、難布設区間における冷却システムの配置の問題を解決することができるからである。 According to the superconducting cable line of the present invention, it is easy to construct a superconducting cable line even when there is a difficult installation section (for example, inside a long-distance tunnel) where a cooling system cannot be easily provided in the installation path of the superconducting cable line. can do. Among the superconducting cables provided in the superconducting cable line of the present invention, if the superconducting cable of the present invention having a longer cooling section length than the conventional one is applied to the difficult-to-lay section, the problem of the arrangement of the cooling system in the difficult-to-lay section can be solved. Because it can.

本発明の超電導ケーブルによれば、従来よりも冷却区間長が長い超電導ケーブルとすることができる。 According to the superconducting cable of the present invention, a superconducting cable having a longer cooling section length than the conventional one can be obtained.

実施形態１に示す超電導ケーブル線路の一部を示す概略構成図である。2 is a schematic configuration diagram showing a part of a superconducting cable line shown in Embodiment 1. FIG. （Ａ）は低温絶縁型の超電導ケーブルに備わるケーブル部の重複領域における概略横断面図、（Ｂ）は常温絶縁型の超電導ケーブルに備わるケーブル部の重複領域における概略横断面図である。(A) is a schematic cross-sectional view in the overlapping region of the cable part provided in the low-temperature insulation type superconducting cable, and (B) is a schematic cross-sectional view in the overlapping region of the cable part provided in the room temperature insulation type superconducting cable.

以下、本発明の実施形態を図面に基づいて説明する。なお、各図面で同一の符号を付しているものは同一物である。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, what attaches | subjects the same code | symbol in each drawing is the same thing.

＜実施形態１＞
≪全体構成≫
図１は、本実施形態の超電導ケーブル線路１０１における冷却システムの設置が困難な区間長のほぼ半分を示す概略構成図である。図１の紙面右端の一点鎖線よりも右側には、一点鎖線よりも左側に示す構成が左右反転した状態で存在している。 <Embodiment 1>
≪Overall structure≫
FIG. 1 is a schematic configuration diagram showing almost half of a section length in which it is difficult to install a cooling system in the superconducting cable line 101 of the present embodiment. The configuration shown on the left side of the alternate long and short dash line is present on the right side of the alternate long and short dash line in FIG.

本実施形態の超電導ケーブル線路１０１は、紙面左側に示す端末９１と、紙面右側の一点鎖線よりも右側にある図示しない端末と、の間で直流送電を行なう送電路である。この超電導ケーブル線路１０１では、超電導ケーブル１の導電路となるケーブル内部部材１０が、接続部Ｊ３を介して、一点鎖線よりも右側にある超電導ケーブルのケーブル内部部材に接続されている。また、本実施形態の超電導ケーブル１０１では、超電導ケーブル１に並列してリターン管８が設けられている（一点鎖線よりも右側にあるリターン管は省略）。リターン管８は、上述した超電導ケーブル１との間で超電導ケーブル１の超電導導体を極低温に維持する冷媒の循環路を構成する部材である。図１に示されるリターン管８と、一点鎖線よりも右側にある図示しないリターン管とは、接続されておらず、図１に示される冷媒の循環は一点鎖線の左側で完結している。上述した超電導ケーブル１とリターン管８とを備える本実施形態１の超電導ケーブル線路１０１の最も特徴とするところは、超電導ケーブル１の一部が、ケーブル内部部材１０の外側を内側冷媒２０Ｃと外側冷媒３０Ｃとで二重に取り囲む二重流路構造となっており、超電導ケーブル１の残部が、ケーブル内部部材１０の外側を内側冷媒２０Ｃで一重に取り囲む一重流路構造となっていることである。以下、超電導ケーブル線路１０１に備わる超電導ケーブル１およびリターン管８の構成を説明し、次いで流路構造の構築状態を説明する。 The superconducting cable line 101 of this embodiment is a power transmission path that performs DC power transmission between a terminal 91 shown on the left side of the drawing and a terminal (not shown) on the right side of the one-dot chain line on the right side of the drawing. In this superconducting cable line 101, the cable internal member 10 which becomes the conductive path of the superconducting cable 1 is connected to the cable internal member of the superconducting cable located on the right side of the one-dot chain line through the connecting portion J3. Moreover, in the superconducting cable 101 of this embodiment, the return pipe 8 is provided in parallel with the superconducting cable 1 (the return pipe on the right side of the one-dot chain line is omitted). The return pipe 8 is a member constituting a refrigerant circulation path that maintains the superconducting conductor of the superconducting cable 1 at a cryogenic temperature with the superconducting cable 1 described above. The return pipe 8 shown in FIG. 1 and a return pipe (not shown) on the right side of the dashed line are not connected, and the refrigerant circulation shown in FIG. 1 is completed on the left side of the dashed line. The most characteristic feature of the superconducting cable line 101 according to the first embodiment including the superconducting cable 1 and the return pipe 8 described above is that a part of the superconducting cable 1 has an inner refrigerant 20C and an outer refrigerant outside the cable internal member 10. This is a double flow path structure that double surrounds 30C, and the remaining part of the superconducting cable 1 has a single flow path structure that surrounds the outside of the cable internal member 10 with the inner refrigerant 20C. Hereinafter, the configuration of the superconducting cable 1 and the return pipe 8 provided in the superconducting cable line 101 will be described, and then the construction state of the flow channel structure will be described.

≪超電導ケーブル≫
超電導ケーブル１は、ケーブル部９０と、ケーブル部９０に備わるケーブル内部部材１０を極低温に冷却する内側冷媒２０Ｃと、ケーブル部９０における内側冷媒の外周側に配される外側冷媒３０Ｃと、を備える。ケーブル部９０は、導電路となるケーブル内部部材１０と、それを内部に収納する内部部材収納管２０と、さらに内部部材収納管２０を内部に収納する外側断熱管３０と、を備える。内部部材収納管２０は、外側断熱管３０よりも長くなっている。そのため、超電導ケーブル１の長手方向において、内部部材収納管２０に外側断熱管３０が重複する重複領域Ｒ１と、内部部材収納管２０に外側断熱管３０が重複しない非重複領域Ｒ２と、が形成されている。即ち、重複領域Ｒ１においては、ケーブル内部部材１０が内側冷媒２０Ｃと外側冷媒３０Ｃとで二重に取り囲まれた二重流路構造となっており、非重複領域Ｒ２においては、ケーブル内部部材１０が内側冷媒２０Ｃで一重に取り囲まれた一重流路構造となっている。 ≪Superconducting cable≫
The superconducting cable 1 includes a cable portion 90, an inner refrigerant 20C that cools the cable inner member 10 included in the cable portion 90 to a cryogenic temperature, and an outer refrigerant 30C that is disposed on the outer peripheral side of the inner refrigerant in the cable portion 90. . The cable portion 90 includes a cable internal member 10 that becomes a conductive path, an internal member storage tube 20 that stores the cable internal member 10 therein, and an outer heat insulating tube 30 that stores the internal member storage tube 20 therein. The inner member storage tube 20 is longer than the outer heat insulating tube 30. Therefore, in the longitudinal direction of the superconducting cable 1, an overlapping region R1 in which the outer heat insulating tube 30 overlaps the inner member storage tube 20 and a non-overlapping region R2 in which the outer heat insulating tube 30 does not overlap the inner member storage tube 20 are formed. ing. That is, in the overlapping region R1, the cable inner member 10 has a double flow path structure that is doubly surrounded by the inner refrigerant 20C and the outer refrigerant 30C, and in the non-overlapping region R2, the cable inner member 10 is It has a single flow path structure surrounded by a single inner refrigerant 20C.

［ケーブル部］
ケーブル部９０の説明にあたり、重複領域Ｒ１における超電導ケーブル１の横断面図である図２（Ａ）を参照する。図２（Ａ）に示すケーブル部９０を備える超電導ケーブル１は、いわゆる低温絶縁型の超電導ケーブルである。なお、低温絶縁型の超電導ケーブルを、常温絶縁型の超電導ケーブルに置換することもできる。その点に関しては、図２（Ｂ）を参照する実施形態２で説明する。 [Cable section]
In description of the cable part 90, FIG. 2 (A) which is a cross-sectional view of the superconducting cable 1 in the overlapping region R1 will be referred to. A superconducting cable 1 including a cable portion 90 shown in FIG. 2A is a so-called low-temperature insulated superconducting cable. Note that the low-temperature insulated superconducting cable can be replaced with a room-temperature insulated superconducting cable. This point will be described in Embodiment 2 with reference to FIG.

低温絶縁型の超電導ケーブルのケーブル部９０は、超電導導体１２を備えるケーブル内部部材１０と、そのケーブル内部部材１０が内部に収納される内部部材収納管２０と、その内部部材収納管２０が内部に収納される外側断熱管３０と、を備える。ケーブル内部部材１０は内部部材収納管２０内で鉛直下方に偏り、内部部材収納管２０は外側断熱管３０内で鉛直下方に偏る傾向にある。 The cable portion 90 of the low-temperature insulated superconducting cable includes a cable internal member 10 including a superconducting conductor 12, an internal member storage tube 20 in which the cable internal member 10 is stored, and the internal member storage tube 20 therein. And an outer heat insulating pipe 30 to be housed. The cable internal member 10 tends to be biased vertically downward within the internal member storage tube 20, and the internal member storage tube 20 tends to be biased vertically downward within the outer heat insulating tube 30.

（ケーブル内部部材）
ケーブル内部部材１０は、代表的には、フォーマ１１の上に順次、超電導導体１２、電気絶縁層１３、外側導体層１４、保護層１５を設けた構成を備える。図１に示すように、内部部材収納管２０の内部で複数のケーブル内部部材１０が接続部Ｊ１，Ｊ２を介して接続される。なお、図示される接続部の数は実際の数よりもかなり少なく表示している。 (Cable internal member)
The cable inner member 10 typically has a configuration in which a superconducting conductor 12, an electrical insulating layer 13, an outer conductor layer 14, and a protective layer 15 are sequentially provided on the former 11. As shown in FIG. 1, a plurality of cable internal members 10 are connected through connection portions J 1 and J 2 inside the internal member storage tube 20. It should be noted that the number of connections shown in the figure is considerably smaller than the actual number.

ケーブル内部部材１０に備わるフォーマ１１は、超電導導体１２の支持体に利用される部材であり、例えば、図２（Ａ）に示すような中実体を利用できる。フォーマ１１の形状としては、撚り線などの中実体の他、パイプ状の中空体を利用することもできる。このフォーマ１１の材質は特に限定されない。単に超電導導体１２の支持体としてフォーマ１１を利用するのであれば、フォーマ１１は樹脂（例えば、繊維強化プラスチック）などの非導電性材料から構成しても良いし、フォーマ１１に異常時電流の分流路としての機能も持たせるのであれば、銅やアルミニウムなどの常電導の金属材料から構成しても良い。 The former 11 provided in the cable internal member 10 is a member used as a support for the superconducting conductor 12, and for example, a solid body as shown in FIG. As the shape of the former 11, a pipe-like hollow body can be used in addition to a solid body such as a stranded wire. The material of the former 11 is not particularly limited. If the former 11 is simply used as a support for the superconducting conductor 12, the former 11 may be made of a non-conductive material such as a resin (for example, fiber reinforced plastic), or the current flow to the former 11 may be shunted. If it also has a function as a path, it may be made of a normal conductive metal material such as copper or aluminum.

超電導導体１２は、例えば酸化物超電導体を備えるテープ状線材をフォーマ１１の外周に螺旋状に巻回することで形成できる。テープ状線材は、単層状に巻回しても良いし、多層状に巻回しても良い。このテープ状線材としては、例えば、Ｂｉ２２２３系超電導テープ線（Ａｇ−ＭｎやＡｇなどの安定化金属中に酸化物超電導体からなるフィラメントが配されたシース線）、ＲＥ１２３系薄膜線材（ＲＥ：希土類元素、例えばＹ、Ｈｏ、Ｎｄ、Ｓｍ、Ｇｄなど。金属基板に酸化物超電導相が成膜された積層線材）が挙げられる。 The superconducting conductor 12 can be formed by, for example, winding a tape-like wire rod having an oxide superconductor spirally around the outer periphery of the former 11. The tape-shaped wire may be wound in a single layer shape or may be wound in a multilayer shape. Examples of the tape-shaped wire include Bi2223 superconducting tape wire (sheath wire in which a filament made of an oxide superconductor is disposed in a stabilizing metal such as Ag-Mn or Ag), RE123 thin film wire (RE: rare earth) Elements such as Y, Ho, Nd, Sm, Gd, etc. (a laminated wire in which an oxide superconducting phase is formed on a metal substrate).

電気絶縁層１３は、例えばクラフト紙とポリプロピレンなどの樹脂フィルムとをラミネートした半合成紙（住友電気工業株式会社製ＰＰＬＰ：登録商標）を超電導導体１２の外周に巻回することで形成できる。電気絶縁層１３は、後述する内部部材収納管２０内で超電導導体１２と共に極低温に冷却される。 The electrical insulating layer 13 can be formed, for example, by winding semi-synthetic paper (PPLP: registered trademark, manufactured by Sumitomo Electric Industries, Ltd.) laminated with kraft paper and a resin film such as polypropylene around the outer periphery of the superconducting conductor 12. The electrical insulating layer 13 is cooled to a cryogenic temperature together with the superconducting conductor 12 in an internal member storage tube 20 described later.

外側導体層１４は、電気絶縁層１３の外周に、例えば超電導導体１２に用いたものと同様の超電導線材を巻回することで形成できる。外側導体層１４を超電導線材から構成した場合、交流ケーブルでは電磁シールドとして利用することができるし、直流ケーブルでは電流の往路と帰路の一方を構成する往路導体層（帰路導体層）、又は中性線として利用することができる。なお、超電導ケーブル１に流れる電流値が大きくない場合などには、外側導体層１４は必ずしも超電導線材で構成する必要はない。その場合、金属テープなどで外側導体層１４を構成すれば良い。 The outer conductor layer 14 can be formed by winding a superconducting wire similar to that used for the superconducting conductor 12, for example, around the outer periphery of the electrical insulating layer 13. When the outer conductor layer 14 is composed of a superconducting wire, it can be used as an electromagnetic shield in an AC cable, and in a DC cable, it is a forward conductor layer (return conductor layer) that constitutes one of a current forward path and a return path, or neutral. Can be used as a line. When the value of the current flowing through the superconducting cable 1 is not large, the outer conductor layer 14 does not necessarily need to be composed of a superconducting wire. In that case, the outer conductor layer 14 may be made of a metal tape or the like.

保護層１５は、例えば、クラフト紙を巻回することで形成することができる。この保護層１５は、外側導体層１４を機械的に保護すると共に、内部部材収納管２０との間を絶縁させるためのものである。 The protective layer 15 can be formed, for example, by winding kraft paper. The protective layer 15 mechanically protects the outer conductor layer 14 and insulates it from the inner member storage tube 20.

（内部部材収納管）
内部部材収納管２０は、上述したケーブル内部部材１０を内部に収納する管路である。本実施形態における内部部材収納管２０は、その全長にわたって断熱構造（真空・非真空を問わない）を有する。なお、図示していないが、内部部材収納管２０は、長手方向に繋ぎ目や接続部が形成されていても良い。 (Inner member storage tube)
The internal member storage tube 20 is a conduit that stores the cable internal member 10 described above. The internal member storage tube 20 in the present embodiment has a heat insulating structure (whether vacuum or non-vacuum) over its entire length. Although not shown, the inner member storage tube 20 may be formed with a joint or a connecting portion in the longitudinal direction.

内部部材収納管２０には、例えば、ケーブル内部部材１０を収納する内管２１と、内管２１を内部に収納する外管２２と、を備える二重管構造を採用することができる。内管２１と外管２２との間に断熱材や、内管２１と外管２２とを離隔させるスペーサを配置すると、内部部材収納管２０の断熱性を高められる。なお、本実施形態では、内部部材収納管２０として二重管構造を利用しているが、三重以上の多重管構造としても良い。 For example, a double tube structure including an inner tube 21 that houses the cable inner member 10 and an outer tube 22 that houses the inner tube 21 therein can be adopted as the inner member housing tube 20. If a heat insulating material or a spacer that separates the inner tube 21 and the outer tube 22 is disposed between the inner tube 21 and the outer tube 22, the heat insulating property of the inner member storage tube 20 can be enhanced. In this embodiment, a double tube structure is used as the internal member storage tube 20, but a multiple tube structure of triple or more may be used.

内管２１及び外管２２の構成材料としては、ステンレス鋼、アルミニウムやその合金などの金属が挙げられる。両管２１，２２の材質を異ならせてもよい。また、両管２１，２２はいずれも、その全長に亘ってコルゲート加工が施されたコルゲート管とすることができる。そうすることで、搬送時や布設時にケーブル部９０を曲げ易くすることができる。 Examples of the constituent material of the inner tube 21 and the outer tube 22 include metals such as stainless steel, aluminum, and alloys thereof. The materials of both pipes 21 and 22 may be different. Moreover, both the pipes 21 and 22 can be corrugated pipes that have been corrugated over their entire length. By doing so, the cable part 90 can be made easy to bend at the time of conveyance or laying.

（外側断熱管）
外側断熱管３０は、上述した内部部材収納管２０を内部に収納する管路であって、断熱構造を有する。この外側断熱管３０も、図示していないが、その長手方向に繋ぎ目や接続部を有していても良い。 (Outside insulation pipe)
The outer heat insulating pipe 30 is a pipe line that houses the internal member storage pipe 20 described above, and has a heat insulating structure. Although not shown, the outer heat insulating tube 30 may have a joint or a connecting portion in the longitudinal direction.

上記外側断熱管３０は、内部部材収納管２０を内部に収納する内管３１と、内管３１を内部に収納する外管３２と、を備える。内管３１と外管３２との間は真空引きされ、それによって真空断熱層が形成されている。その他、内管３１と外管３２との間にスーパーインシュレーションといった断熱材や、内管３１と外管３２とを離隔させるスペーサを配置すると、外側断熱管３０の断熱性を高められる。なお、本実施形態では、断熱管として二重構造の断熱管を利用しているが、三重以上の多重管構造としても良い。 The outer heat insulating tube 30 includes an inner tube 31 that houses the inner member housing tube 20 inside, and an outer tube 32 that houses the inner tube 31 inside. A vacuum is drawn between the inner tube 31 and the outer tube 32, thereby forming a vacuum heat insulating layer. In addition, if a heat insulating material such as a super insulation or a spacer that separates the inner tube 31 and the outer tube 32 is disposed between the inner tube 31 and the outer tube 32, the heat insulating property of the outer heat insulating tube 30 can be improved. In the present embodiment, a double-insulated heat insulating tube is used as the heat insulating tube, but a triple or more multiple tube structure may be used.

内管３１及び外管３２の構成材料としては、ステンレス鋼、アルミニウムやその合金などの金属が挙げられる。両管３１，３２の材質を異ならせてもよい。また、両管３１，３２はいずれも、その全長に亘ってコルゲート加工が施されたコルゲート管とすることができる。そうすることで、搬送時や布設時にケーブル部９０を曲げ易くすることができる。 Examples of the constituent material of the inner tube 31 and the outer tube 32 include metals such as stainless steel, aluminum, and alloys thereof. The materials of both pipes 31 and 32 may be different. Moreover, both the pipes 31 and 32 can be corrugated pipes that have been corrugated over their entire length. By doing so, the cable part 90 can be made easy to bend at the time of conveyance or laying.

［内側冷媒］
以上説明したケーブル部９０の内部部材収納管２０の内部には内側冷媒２０Ｃが循環される。この内側冷媒２０Ｃにより、ケーブル内部部材１０の超電導導体１２を極低温に冷却し、超電導導体１２を超電導状態に維持することができる。内側冷媒２０Ｃとしては、液体窒素（沸点；約７７Ｋ）や、液体空気（沸点；約８３Ｋ）、液体酸素（沸点；約９０Ｋ）、液体水素（沸点；約２０．６Ｋ）、液体ヘリウム（沸点；約４．２Ｋ）などを利用することができる。ケーブル内部部材１０に備わる超電導導体１２が、例えばＢｉ２２２３系や、ＲＥ１２３系（ＲＥ：希土類元素、例えばＹ、Ｈｏ、Ｎｄ、Ｓｍ、Ｇｄなど）などの高温超電導材料の場合、約８５Ｋ以下の沸点をもつ液体冷媒が好ましく、安全性、入手の容易さ、絶縁性、コストを考慮して、液体窒素が最も好ましい。 [Inside refrigerant]
The inner refrigerant 20C is circulated inside the inner member storage tube 20 of the cable portion 90 described above. The inner refrigerant 20C can cool the superconducting conductor 12 of the cable inner member 10 to a cryogenic temperature and maintain the superconducting conductor 12 in a superconducting state. As the inner refrigerant 20C, liquid nitrogen (boiling point: about 77K), liquid air (boiling point: about 83K), liquid oxygen (boiling point: about 90K), liquid hydrogen (boiling point: about 20.6K), liquid helium (boiling point; About 4.2K) can be used. When the superconducting conductor 12 provided in the cable internal member 10 is a high-temperature superconducting material such as Bi2223 series or RE123 series (RE: rare earth elements such as Y, Ho, Nd, Sm, Gd, etc.), it has a boiling point of about 85K or less. Liquid nitrogen is preferable, and liquid nitrogen is most preferable in view of safety, availability, insulation, and cost.

［外側冷媒］
図２（Ａ）に示すように、外側冷媒３０Ｃは、ケーブル部９０における外側断熱管３０の内部で、かつ内部部材収納管２０の外側の空間に循環される。本実施形態では、外側冷媒３０Ｃの流路断面積は、内側冷媒２０Ｃの流路断面積とほぼ同じとなっている。この外側冷媒３０Ｃの循環によって外側断熱管３０を介した侵入熱を処理し、内部部材収納管２０の温度上昇を抑制することができる。内部部材収納管２０の温度上昇を抑制することができれば、その内部部材収納管２０の内部に充填される内側冷媒２０Ｃの温度上昇を抑制でき、超電導導体１２を極低温に維持することができる。 [Outside refrigerant]
As shown in FIG. 2A, the outer refrigerant 30 C is circulated inside the outer heat insulating pipe 30 in the cable portion 90 and in a space outside the inner member housing pipe 20. In the present embodiment, the channel cross-sectional area of the outer refrigerant 30C is substantially the same as the channel cross-sectional area of the inner refrigerant 20C. By circulating the outer refrigerant 30C, the intrusion heat through the outer heat insulating pipe 30 can be processed, and the temperature rise of the inner member housing pipe 20 can be suppressed. If the temperature rise of the internal member storage tube 20 can be suppressed, the temperature increase of the inner refrigerant 20C filled in the internal member storage tube 20 can be suppressed, and the superconducting conductor 12 can be maintained at a very low temperature.

外側冷媒３０Ｃには、上述した内側冷媒２０Ｃに利用することができる液体冷媒を用いることができる。外側冷媒３０Ｃと内側冷媒２０Ｃとに同一の液体冷媒を用いても良いし、異なる液体冷媒を用いても良い。後者の場合、外側冷媒３０Ｃとして、内側冷媒２０Ｃの沸点よりも低沸点の液体冷媒を利用することが好ましい。また、外側冷媒３０Ｃは、固液混合としても良い。例えば、外側冷媒３０Ｃとして液体窒素を利用する場合、その液体窒素中にスラッシュ窒素を含有させても構わない。スラッシュ窒素を用いることで液体窒素のガス化を遅らせることができる。 As the outer refrigerant 30C, a liquid refrigerant that can be used for the inner refrigerant 20C described above can be used. The same liquid refrigerant may be used for the outer refrigerant 30C and the inner refrigerant 20C, or different liquid refrigerants may be used. In the latter case, it is preferable to use a liquid refrigerant having a boiling point lower than that of the inner refrigerant 20C as the outer refrigerant 30C. Further, the outer refrigerant 30C may be solid-liquid mixed. For example, when liquid nitrogen is used as the outer refrigerant 30C, slush nitrogen may be included in the liquid nitrogen. Gasification of liquid nitrogen can be delayed by using slush nitrogen.

≪リターン管≫
本実施形態におけるリターン管８は、図１に示すように、上述した超電導ケーブル１からケーブル内部部材１０を除いたような構成を備える。即ち、リターン管８は、内側冷媒２０Ｃを流通させる内側流通管８１と、内側流通管８１を内部に収納すると共に、外側冷媒３０Ｃを流通させる外側流通管８２とを備える。また、内側流通管８１が外側流通管８２よりも長くなっており、従ってリターン管８においても重複領域Ｒ１と非重複領域Ｒ２とが形成される。内側流通管８１には、超電導ケーブル１の内部部材収納管２０と同様の二重管構造を利用することができ、また、外側流通管８２には、超電導ケーブル１の外側断熱管３０と同様の二重管構造を利用することができる。 ≪Return pipe≫
As shown in FIG. 1, the return pipe 8 in the present embodiment has a configuration in which the cable internal member 10 is removed from the superconducting cable 1 described above. That is, the return pipe 8 includes an inner circulation pipe 81 that circulates the inner refrigerant 20C, and an outer circulation pipe 82 that accommodates the inner circulation pipe 81 and circulates the outer refrigerant 30C. Further, the inner flow pipe 81 is longer than the outer flow pipe 82, and therefore, an overlapping region R 1 and a non-overlapping region R 2 are also formed in the return pipe 8. A double pipe structure similar to the inner member housing pipe 20 of the superconducting cable 1 can be used for the inner distribution pipe 81, and the same as the outer heat insulating pipe 30 of the superconducting cable 1 can be used for the outer distribution pipe 82. A double tube structure can be utilized.

ここで、内側流通管８１の流路断面積および外側流通管８２の流路断面積はそれぞれ、内部部材収納管２０の流路断面積および外側断熱管３０の流路断面積と同等以上としておく。特に、リターン管８と超電導ケーブル１とで流路断面積を同じとすると、内側冷媒２０Ｃと外側冷媒３０Ｃの循環が阻害されることがなく、しかもリターン管８の外径を超電導ケーブル１の外径よりも小さくすることができる。また、リターン管８の流路断面積を、超電導ケーブル１の流路断面積よりも大きくすれば、冷却区間長を長くするために有効である。その場合でも、リターン管８の流路断面積を大きくしすぎなければ、リターン管８の外径を超電導ケーブル１の外径以下とすることは可能である。 Here, the flow path cross-sectional area of the inner flow pipe 81 and the flow cross-sectional area of the outer flow pipe 82 are equal to or larger than the flow path cross-sectional area of the internal member storage pipe 20 and the flow cross-section area of the outer heat insulation pipe 30, respectively. . In particular, if the return pipe 8 and the superconducting cable 1 have the same flow path cross-sectional area, the circulation of the inner refrigerant 20C and the outer refrigerant 30C is not hindered, and the outer diameter of the return pipe 8 is set outside the superconducting cable 1. It can be made smaller than the diameter. Further, if the flow path cross-sectional area of the return pipe 8 is made larger than the flow path cross-sectional area of the superconducting cable 1, it is effective for increasing the cooling section length. Even in that case, the outer diameter of the return pipe 8 can be made equal to or smaller than the outer diameter of the superconducting cable 1 unless the flow passage cross-sectional area of the return pipe 8 is excessively increased.

≪流路構造の構築状態≫
図１に示すように、超電導ケーブル１の内部部材収納管２０と、リターン管８の内側流通管８１とは、接続部Ｊ３の位置で内側流路接続部２９によって接続される。内側流路接続部２９は、外部環境からの熱侵入を抑制する断熱構造を有している。この内側流路接続部２９によって、超電導ケーブル１とリターン管８との間で内側冷媒２０Ｃの循環路が形成される。 <Construction state of flow channel structure>
As shown in FIG. 1, the internal member storage pipe 20 of the superconducting cable 1 and the inner flow pipe 81 of the return pipe 8 are connected by an inner flow path connection portion 29 at the position of the connection portion J3. The inner flow path connection portion 29 has a heat insulating structure that suppresses heat intrusion from the external environment. By this inner flow path connection portion 29, a circulation path for the inner refrigerant 20 C is formed between the superconducting cable 1 and the return pipe 8.

内側冷媒２０Ｃは、端末９１の近傍に設けられる内側冷媒の循環冷却機構４０によって内部部材収納管２０内に循環される（図中の白抜き矢頭の付いた実線矢印を参照）。当該循環冷却機構４０は、リザーバタンク４１と、往路管４２と、復路管４３と、液化機４４と、ポンプ４５と、を備える。リザーバタンク４１は断熱構造を備え、内側冷媒２０Ｃの温度変化に伴う内側冷媒２０Ｃの体積変化を吸収すると共に、内側冷媒２０Ｃを貯留する部材である。往路管４２は、端末９１近傍でリザーバタンク４１と内部部材収納管２０とを繋ぐ断熱管であり、復路管４３は、リザーバタンク４１と内側流通管８１とを繋ぐ断熱管である。冷却システム４４は、内側冷媒２０Ｃを冷却するシステムであって、冷凍機やポンプなどで構成される。また、ポンプ４５は、往路管４２の途中に設けられ、内側冷媒２０Ｃを内部部材収納管２０に送り出す部材であって、市販のものを利用することができる。 The inner refrigerant 20C is circulated in the inner member storage tube 20 by the inner refrigerant circulation cooling mechanism 40 provided in the vicinity of the terminal 91 (see the solid line arrow with a white arrowhead in the figure). The circulation cooling mechanism 40 includes a reservoir tank 41, an outward pipe 42, a return pipe 43, a liquefier 44, and a pump 45. The reservoir tank 41 has a heat insulating structure, and is a member that absorbs the volume change of the inner refrigerant 20C accompanying the temperature change of the inner refrigerant 20C and stores the inner refrigerant 20C. The forward path pipe 42 is a heat insulation pipe that connects the reservoir tank 41 and the internal member storage pipe 20 in the vicinity of the terminal 91, and the return path pipe 43 is a heat insulation pipe that connects the reservoir tank 41 and the inner distribution pipe 81. The cooling system 44 is a system that cools the inner refrigerant 20C, and includes a refrigerator, a pump, and the like. Further, the pump 45 is a member that is provided in the middle of the forward path pipe 42 and sends out the inner refrigerant 20C to the internal member storage pipe 20, and a commercially available one can be used.

内側冷媒２０Ｃの循環は次のように行なわれる。まず、リザーバタンク４１に貯留される内側冷媒２０Ｃは、ポンプ４５によって往路管４２に送り出され、端末９１の近傍で内部部材収納管２０の内部に流れ込む。内部部材収納管２０に流れ込んだ内側冷媒２０Ｃは、紙面右側に向かって流れ、紙面右端の内側流路接続部２９を介して、リターン管８の内側流通管８１に流れ込む。そして、リターン管８を紙面左側に向かって流れる内側冷媒２０Ｃは、紙面左端で内側冷媒の循環冷却機構４０の復路管４３に流れ込み、リザーバタンク４１に戻る。リザーバタンク４１に戻った内側冷媒２０Ｃは冷却システム４４で冷却され、再び往路管４２に送り出される。 Circulation of the inner refrigerant 20C is performed as follows. First, the inner refrigerant 20 C stored in the reservoir tank 41 is sent out to the forward pipe 42 by the pump 45 and flows into the internal member storage pipe 20 in the vicinity of the terminal 91. The inner refrigerant 20 C that has flowed into the internal member storage pipe 20 flows toward the right side of the page, and flows into the inner flow pipe 81 of the return pipe 8 via the inner channel connection portion 29 at the right end of the page. The inner refrigerant 20 C flowing through the return pipe 8 toward the left side of the drawing flows into the return pipe 43 of the inner refrigerant circulation cooling mechanism 40 at the left end of the drawing and returns to the reservoir tank 41. The inner refrigerant 20 C that has returned to the reservoir tank 41 is cooled by the cooling system 44 and is sent out to the forward pipe 42 again.

一方、超電導ケーブル１の外側断熱管３０と、リターン管８の外側流通管８２とは、重複領域Ｒ１と非重複領域Ｒ２の境界近傍で、外側流路接続部３９によって接続されている。外側流路接続部３９も、外部環境からの熱侵入を抑制する断熱構造を有している。この外側流路接続部３９によって、超電導ケーブル１とリターン管８との間で外側冷媒３０Ｃの循環路が形成される。 On the other hand, the outer heat insulating pipe 30 of the superconducting cable 1 and the outer flow pipe 82 of the return pipe 8 are connected by an outer flow path connecting portion 39 in the vicinity of the boundary between the overlapping region R1 and the non-overlapping region R2. The outer flow path connecting portion 39 also has a heat insulating structure that suppresses heat intrusion from the external environment. The outer flow path connecting portion 39 forms a circulation path for the outer refrigerant 30 C between the superconducting cable 1 and the return pipe 8.

外側冷媒３０Ｃは、外側冷媒の循環冷却機構５０によって外側断熱管３０内に循環される（図中の点線矢印を参照）。当該循環冷却機構５０は、リザーバタンク５１と、往路管５２と、復路管５３と、液化機５４と、ポンプ５５と、を備える。リザーバタンク５１は断熱構造を備え、外側冷媒３０Ｃの温度変化に伴う外側冷媒３０Ｃの体積変化を吸収すると共に、外側冷媒３０Ｃを貯留する部材である。往路管５２は、端末９１近傍でリザーバタンク５１と外側断熱管３０とを繋ぐ断熱管であり、復路管５３は、リザーバタンク５１と外側流通管８２とを繋ぐ断熱管である。冷却システム５４は、外側冷媒３０Ｃを冷却するシステムであって、冷凍機やポンプなどで構成される。また、ポンプ５５は、往路管５２の途中に設けられ、外側冷媒３０Ｃを外側断熱管３０に送り出す部材であって、市販のものを利用することができる。 The outer refrigerant 30C is circulated in the outer heat insulating pipe 30 by the outer refrigerant circulation cooling mechanism 50 (see the dotted arrow in the figure). The circulation cooling mechanism 50 includes a reservoir tank 51, an outward pipe 52, a return pipe 53, a liquefier 54, and a pump 55. The reservoir tank 51 has a heat insulating structure, and is a member that absorbs a volume change of the outer refrigerant 30C accompanying a temperature change of the outer refrigerant 30C and stores the outer refrigerant 30C. The forward pipe 52 is a heat insulating pipe that connects the reservoir tank 51 and the outer heat insulating pipe 30 in the vicinity of the terminal 91, and the return pipe 53 is a heat insulating pipe that connects the reservoir tank 51 and the outer flow pipe 82. The cooling system 54 is a system that cools the outer refrigerant 30C, and includes a refrigerator, a pump, and the like. The pump 55 is a member that is provided in the middle of the outward pipe 52 and that sends out the outer refrigerant 30C to the outer heat insulating pipe 30, and a commercially available one can be used.

外側冷媒３０Ｃの循環は次のように行なわれる。まず、リザーバタンク５１に貯留される外側冷媒３０Ｃは、ポンプ５５によって往路管５２に送り出され、端末９１の近傍で外側断熱管３０の内部に流れ込む。外側断熱管３０に流れ込んだ外側冷媒３０Ｃは、紙面右側に向かって流れ、重複領域Ｒ１と非重複領域Ｒ２との境界近傍で外側流路接続部３９を介して、リターン管８の外側流通管８２に流れ込む。そして、リターン管８を紙面左側に向かって流れる外側冷媒３０Ｃは、紙面左端で外側冷媒の循環冷却機構５０の復路管５３に流れ込み、リザーバタンク５１に戻る。リザーバタンク５１に戻った外側冷媒３０Ｃは冷却システム５４で冷却され、再び往路管５２に送り出される。 Circulation of the outer refrigerant 30C is performed as follows. First, the outer refrigerant 30 C stored in the reservoir tank 51 is sent out to the forward pipe 52 by the pump 55 and flows into the outer heat insulating pipe 30 in the vicinity of the terminal 91. The outer refrigerant 30C that has flowed into the outer heat insulating pipe 30 flows toward the right side of the drawing, and is located near the boundary between the overlapping area R1 and the non-overlapping area R2 via the outer flow path connecting portion 39, and the outer circulation pipe 82 of the return pipe 8. Flow into. The outer refrigerant 30 C flowing through the return pipe 8 toward the left side of the drawing flows into the return pipe 53 of the outer refrigerant circulation cooling mechanism 50 at the left end of the drawing and returns to the reservoir tank 51. The outer refrigerant 30 C that has returned to the reservoir tank 51 is cooled by the cooling system 54, and sent out to the forward pipe 52 again.

≪本発明の超電導ケーブル線路の効果≫
以上説明した超電導ケーブル線路１０１（超電導ケーブル１）によれば、その冷却区間長を従来の超電導ケーブルに比べて大幅に長くすることができる。具体的には、本実施形態における内部部材収納管２０と同じ流路断面積を有し、その外部に外側断熱管３０がない従来の一重流路構造の超電導ケーブルの冷却区間長を『１』とした場合、流路断面積を２倍とした一重流路構造の冷却区間長は『約１．４』となる（下記計算例２を参照）のに対し、内側流路と同じ流路断面積を有する外部流路を構成する本実施形態の超電導ケーブル線路１０１の冷却区間長を『約１．６』とすることができる（下記計算例１を参照）。なお、計算にあたっては、各構成の単位体積当たりの流路抵抗は同じと見做す。 ≪Effect of superconducting cable line of the present invention≫
According to the superconducting cable line 101 (superconducting cable 1) described above, the cooling section length can be significantly increased as compared with the conventional superconducting cable. Specifically, the cooling section length of the conventional superconducting cable having the same flow path cross-sectional area as that of the internal member storage pipe 20 in the present embodiment and having no outer heat insulating pipe 30 outside thereof is “1”. In this case, the cooling section length of the single flow path structure with the flow path cross-sectional area doubled is “about 1.4” (see calculation example 2 below), whereas the flow path breaks the same as the inner flow path. The cooling section length of the superconducting cable line 101 of the present embodiment constituting the external flow path having an area can be set to “about 1.6” (see calculation example 1 below). In the calculation, the flow path resistance per unit volume of each component is assumed to be the same.

［計算例１］
重複領域Ｒ１の長さをＡ１、非重複領域Ｒ２の長さをＢ１とした場合、外側冷媒３０Ｃでは、Ａ１の長さで侵入熱の熱処理を行なうと共に、Ａ１の長さの圧力損失に対応する必要がある。一方、内側冷媒２０Ｃでは、Ｂ１の長さで侵入熱の熱処理を行なうと共に、Ａ１＋Ｂ１の長さの圧力損失に対応する必要がある。必要な冷媒の流量は、熱負荷（侵入熱や発生熱）を処理する区間の長さに比例し、圧力損失は冷媒流量（熱負荷区間の長さ）×流路の長さに比例することから、外側冷媒３０Ｃの圧力損失＝ｋ×Ａ１×Ａ１、内側冷媒２０Ｃの圧力損失＝ｋ×Ｂ１×（Ａ１＋Ｂ１）となる（ｋは流路抵抗に当たる係数）。外側冷媒３０Ｃが流れる部分の流路抵抗と、内側冷媒２０Ｃが流れる部分の流路抵抗とを同等とする場合、外側冷媒３０Ｃの圧力損失と内側冷媒２０Ｃの圧力損失とが同じとなるとき、即ちｋ×Ａ１×Ａ１＝ｋ×Ｂ１×（Ａ１＋Ｂ１）となるときのＢ１は約０．６１８×Ａ１となる。つまり、冷却区間長を、Ａ１＋０．６１８×Ａ１、即ちＡ１の約１．６倍とすることができる。 [Calculation Example 1]
When the length of the overlapping region R1 is A1 and the length of the non-overlapping region R2 is B1, the outer refrigerant 30C performs the heat treatment of the intrusion heat with the length of A1, and corresponds to the pressure loss of the length of A1. There is a need. On the other hand, in the inner refrigerant 20C, it is necessary to perform the heat treatment of the intrusion heat with the length of B1 and to cope with the pressure loss of the length of A1 + B1. The required flow rate of the refrigerant is proportional to the length of the section that processes the heat load (intrusion heat and generated heat), and the pressure loss is proportional to the refrigerant flow rate (the length of the heat load section) x the length of the flow path. Therefore, the pressure loss of the outer refrigerant 30C = k × A1 × A1 and the pressure loss of the inner refrigerant 20C = k × B1 × (A1 + B1) (k is a coefficient corresponding to the flow path resistance). When the flow resistance of the portion through which the outer refrigerant 30C flows is equal to the flow resistance of the portion through which the inner refrigerant 20C flows, when the pressure loss of the outer refrigerant 30C and the pressure loss of the inner refrigerant 20C are the same, B1 when k × A1 × A1 = k × B1 × (A1 + B1) is about 0.618 × A1. That is, the cooling section length can be A1 + 0.618 × A1, that is, about 1.6 times A1.

［計算例２］
一方、基準となる一重流路構造の長さをＡ１、その流路抵抗に当たる係数をｋとしたとき、流路断面積を２倍とした一重流路構造の流路抵抗に当たる係数はｋ／２になる。２倍断面積の一重流路構造の冷却区間長をＡ１’とした場合、その２倍断面積の一重流路構造における冷媒の圧力損失＝（ｋ／２）×Ａ１’×Ａ１’となる。基準となる一重流路構造での冷媒の圧力損失と、２倍断面積の一重流路構造での冷媒の圧力損失と、が同じとなるとき、即ちｋ×Ａ１×Ａ１＝（ｋ／２）×Ａ１’×Ａ１’となるときのＡ１’は約１．４１４×Ａ１となる。即ち、断面積を２倍にすることで、冷却区間長は約１．４倍にできる。 [Calculation Example 2]
On the other hand, when the length of the reference single channel structure is A1, and the coefficient corresponding to the channel resistance is k, the coefficient corresponding to the channel resistance of the single channel structure in which the channel cross-sectional area is doubled is k / 2. become. When the cooling section length of the single flow path structure having a double cross-sectional area is A1 ′, the pressure loss of the refrigerant in the single flow path structure having a double cross-sectional area = (k / 2) × A1 ′ × A1 ′. When the pressure loss of the refrigerant in the single channel structure serving as a reference and the pressure loss of the refrigerant in the single channel structure having a double cross-sectional area are the same, that is, k × A1 × A1 = (k / 2) A1 ′ when × A1 ′ × A1 ′ is about 1.414 × A1. That is, the cooling section length can be increased by about 1.4 times by doubling the cross-sectional area.

また、本実施形態の超電導ケーブル線路１０１（超電導ケーブル１）において、外側冷媒３０Ｃがケーブル内部部材１０の電気絶縁層１３と隔離されていることも、超電導ケーブル１の冷却区間長を長くすることができる要因の一つである。ＰＰＬＰ（登録商標）を巻回することで構成されるケーブル内部部材１０の電気絶縁層１３において、液体冷媒の圧力が低いと絶縁性能が不安定になることが知られている。安定した絶縁性能を確保するために、従来の超電導ケーブルでは、液体冷媒の最低圧力は０．２ＭＰａ（ベース圧力）以上とするのが一般的である。これに対して、本実施形態の超電導ケーブル１では、外側冷媒３０Ｃの循環にあたり上記ベース圧力を考慮する必要がなく、循環路中における外側冷媒３０Ｃ最高圧力と最低圧力との圧力差を従来構成よりも大きくすることができる。そのため、圧力差を大きくできる分だけ流量の調整幅を大きくすることができ、超電導ケーブル１の冷却区間長を長くすることができる。なお、外側冷媒３０Ｃがケーブル内部部材１０の電気絶縁層１３と隔離されていることで、外側冷媒３０Ｃの温度変化幅も大きくすることができる可能性がある。 Further, in the superconducting cable line 101 (superconducting cable 1) of the present embodiment, the fact that the outer refrigerant 30C is isolated from the electrical insulating layer 13 of the cable inner member 10 can also increase the cooling section length of the superconducting cable 1. One of the possible factors. It is known that in the electrical insulation layer 13 of the cable internal member 10 configured by winding PPLP (registered trademark), the insulation performance becomes unstable when the pressure of the liquid refrigerant is low. In order to ensure stable insulation performance, in the conventional superconducting cable, the minimum pressure of the liquid refrigerant is generally 0.2 MPa (base pressure) or more. On the other hand, in the superconducting cable 1 of the present embodiment, it is not necessary to consider the base pressure when the outer refrigerant 30C is circulated, and the pressure difference between the outer refrigerant 30C maximum pressure and the minimum pressure in the circulation path is different from the conventional configuration. Can also be increased. Therefore, the adjustment range of the flow rate can be increased as much as the pressure difference can be increased, and the cooling section length of the superconducting cable 1 can be increased. In addition, since the outer refrigerant 30C is isolated from the electrical insulating layer 13 of the cable inner member 10, there is a possibility that the temperature change width of the outer refrigerant 30C can be increased.

＜実施形態２＞
実施形態１で説明した低温絶縁型の超電導ケーブルを、常温絶縁型の超電導ケーブルに置換することもできる。常温絶縁型の超電導ケーブルとして、例えば、図２（Ｂ）の横断面図に示すケーブル部９０’を備える超電導ケーブルを利用することができる。なお、この置換は、後述する実施形態においても同様に行なうことができる。 <Embodiment 2>
The low-temperature insulated superconducting cable described in the first embodiment can be replaced with a room-temperature insulated superconducting cable. As the room temperature insulation type superconducting cable, for example, a superconducting cable including a cable portion 90 ′ shown in the cross-sectional view of FIG. 2B can be used. This replacement can be performed in the same manner in the embodiments described later.

≪常温絶縁型超電導ケーブル≫
図２（Ｂ）に示す常温絶縁型の超電導ケーブルのケーブル部９０’は、図２（Ａ）に示す低温絶縁型の超電導ケーブルのケーブル部９０と同様、ケーブル内部部材１０’と、内部部材収納管２０’と、外側断熱管３０’と、を備える。両型の主たる相違点は、ケーブル内部部材の構成、および外側断熱管の構成にある。以下、両型の相違点を中心に説明する。 ≪Room-temperature insulated superconducting cable≫
The cable portion 90 ′ of the room temperature insulation type superconducting cable shown in FIG. 2B is similar to the cable portion 90 of the low temperature insulation type superconducting cable shown in FIG. A tube 20 ′ and an outer heat insulating tube 30 ′ are provided. The main difference between the two types is the configuration of the cable inner member and the configuration of the outer heat insulating tube. Hereinafter, the difference between the two types will be mainly described.

［ケーブル内部部材］
ケーブル内部部材１０’は、フォーマ１１の外周に超電導導体１２と保護層１５を備えるが、図２（Ａ）のケーブル内部部材１０における電気絶縁層１３と外側導体層１４に相当するものを有さない。超電導導体１２は、端末やジョイント部で内部部材収納管２０’に接続され、超電導導体１２と内部部材収納管２０’とは同電位となっている。そこで、後述する外側断熱管３０’の構成に示すように、常温絶縁型の超電導ケーブルでは、外側断熱管３０’の外周に電気絶縁層３３を設けている。なお、上記ケーブル内部部材１０’における超電導導体１２の外周には、保護層１５を設けることが好ましい。保護層１５としては、クラフトテープなどを利用することができる。 [Cable internal members]
The cable inner member 10 ′ includes the superconducting conductor 12 and the protective layer 15 on the outer periphery of the former 11, but has a portion corresponding to the electric insulating layer 13 and the outer conductor layer 14 in the cable inner member 10 of FIG. Absent. The superconducting conductor 12 is connected to the inner member housing tube 20 ′ at the terminal or joint portion, and the superconducting conductor 12 and the inner member housing tube 20 ′ have the same potential. Therefore, as shown in the configuration of the outer heat insulating tube 30 ′, which will be described later, in the room temperature insulation type superconducting cable, an electrical insulating layer 33 is provided on the outer periphery of the outer heat insulating tube 30 ′. Note that a protective layer 15 is preferably provided on the outer periphery of the superconducting conductor 12 in the cable inner member 10 '. As the protective layer 15, craft tape or the like can be used.

［外側断熱管］
外側断熱管３０’は、内管３１と外管３２に加え、外管３２の外周に電気絶縁層３３を備える。電気絶縁層３３は、所望の耐電圧特性を有するものであって、常温環境で利用される。この電気絶縁層３３には、常電導ケーブルで実績がある電気絶縁強度に優れる材料、代表的にはＣＶケーブルに利用される架橋ポリエチレン（ＸＬＰＥ）などを利用できる。架橋ポリエチレンなどの絶縁性樹脂であれば、外管３２の外周に絶縁性樹脂を押し出すだけで電気絶縁層３３を容易に形成できる。 [Outside insulation pipe]
The outer heat insulating tube 30 ′ includes an electric insulating layer 33 on the outer periphery of the outer tube 32 in addition to the inner tube 31 and the outer tube 32. The electrical insulating layer 33 has a desired withstand voltage characteristic and is used in a normal temperature environment. The electrical insulating layer 33 can be made of a material having a proven record in normal conducting cables and having excellent electrical insulation strength, typically, crosslinked polyethylene (XLPE) used for CV cables. In the case of an insulating resin such as cross-linked polyethylene, the electrical insulating layer 33 can be easily formed simply by extruding the insulating resin to the outer periphery of the outer tube 32.

＜実施形態３＞
実施形態１で説明した内部部材収納管２０は、その断熱性能を変更可能に構成しても良い。その場合、例えば、内部部材収納管２０の内管２１と外管２２との間の内部空間に繋がる真空ポートを内部部材収納管２０に設ければ良い。この真空ポートを用いて上記内部空間を真空引きすれば、内部部材収納管２０の断熱性能を上昇させることができる。逆に真空ポートを用いて内部空間内に窒素ガスなどを導入すれば、内部部材収納管２０の断熱性能を低下させることができる。 <Embodiment 3>
The internal member storage tube 20 described in the first embodiment may be configured so that its heat insulation performance can be changed. In that case, for example, a vacuum port connected to the internal space between the inner tube 21 and the outer tube 22 of the inner member housing tube 20 may be provided in the inner member housing tube 20. If the internal space is evacuated using this vacuum port, the heat insulation performance of the internal member storage tube 20 can be increased. Conversely, if nitrogen gas or the like is introduced into the internal space using the vacuum port, the heat insulation performance of the internal member storage tube 20 can be lowered.

内部部材収納管２０の断熱性能を変更可能に構成することで、超電導ケーブル１のケーブル内部部材１０を冷却する際、ケーブル内部部材１０に過大な張力が作用し、ケーブル内部部材１０が損傷することを防止できる。具体的には、まず内部部材収納管２０の断熱性能を高くし、外側冷媒３０Ｃの充填を行う。当初はガス状態での冷却が進められ、所定の温度に到達した時点で液体冷媒を充填し、最終的に循環させる。外側冷媒３０Ｃによって内部部材収納管２０の重複領域Ｒ１の外周の温度が全長にわたってほぼ低下した状態となったら、内部部材収納管２０の断熱性能を低くする。そうすることで、内部部材収納管２０の内部が、内部部材収納管２０の全長にわたって冷却され、その内部部材収納管２０の内部に収納されるケーブル内部部材１０も全長にわたって冷却される。ケーブル内部部材１０の全長を冷却することができれば、ケーブル内部部材１０の長手方向にケーブル内部部材１０の収縮差が生じることを回避でき、ケーブル内部部材１０に過大な張力が作用することを回避できる。 By configuring the heat insulation performance of the internal member storage tube 20 to be changeable, when the cable internal member 10 of the superconducting cable 1 is cooled, excessive tension acts on the cable internal member 10 and the cable internal member 10 is damaged. Can be prevented. Specifically, first, the heat insulation performance of the inner member storage tube 20 is increased, and the outer refrigerant 30C is charged. At first, cooling in a gas state is advanced, and when a predetermined temperature is reached, liquid refrigerant is filled and finally circulated. When the temperature of the outer periphery of the overlapping region R1 of the internal member storage tube 20 is substantially lowered over the entire length by the outer refrigerant 30C, the heat insulation performance of the internal member storage tube 20 is lowered. By doing so, the inside of the internal member storage tube 20 is cooled over the entire length of the internal member storage tube 20, and the cable internal member 10 stored in the internal member storage tube 20 is also cooled over the entire length. If the entire length of the cable internal member 10 can be cooled, it is possible to avoid a difference in contraction of the cable internal member 10 in the longitudinal direction of the cable internal member 10 and to avoid excessive tension acting on the cable internal member 10. .

なお、内部部材収納管２０内への内側冷媒２０Ｃの循環は、内部部材収納管２０内が十分に冷却されてから開始すれば良い。また、ケーブル内部部材１０を冷却した後の内部部材収納管２０の断熱性能は、高くする。 The circulation of the inner refrigerant 20C into the internal member storage tube 20 may be started after the internal member storage tube 20 is sufficiently cooled. Moreover, the heat insulation performance of the internal member accommodation pipe | tube 20 after cooling the cable internal member 10 is made high.

＜実施形態４＞
実施形態１では、内部部材収納管２０がその全長にわたって断熱構造を備える例を説明した。これに対して、内部部材収納管２０のうち、非重複領域Ｒ２に対応する部分のみを断熱構造とし、残りの重複領域Ｒ１に対応する部分を伝熱構造としても良い。この構成は、重複領域Ｒ１において、内部冷媒２０Ｃと外側冷媒３０Ｃとの間で熱交換を可能にする構成である。この構成を採用した超電導ケーブル線路は、送電に伴って超電導導体が発熱する交流送電に適している。 <Embodiment 4>
Embodiment 1 demonstrated the example in which the internal member storage pipe | tube 20 is equipped with the heat insulation structure over the full length. On the other hand, only the part corresponding to the non-overlapping area | region R2 among the internal member accommodation pipe | tubes 20 is made into a heat insulation structure, and the part corresponding to the remaining overlapping area | region R1 is good also as a heat-transfer structure. This configuration is a configuration that enables heat exchange between the internal refrigerant 20C and the outer refrigerant 30C in the overlapping region R1. A superconducting cable line employing this configuration is suitable for AC power transmission in which the superconducting conductor generates heat as power is transmitted.

上記断熱構造と伝熱構造とが混在した内部部材収納管２０は、例えば、伝熱構造の第一分割管と、断熱構造の第二分割管と、を接続することで得られる。伝熱構造の第一分割管としては、例えばステンレス製の一重管を利用することができ、その長さは外側断熱管３０とほぼ同尺である。一方、断熱構造の第二分割管としては、実施形態１で説明した内管と外管とからなる二重管構造を利用することができる。これら第一断熱管と第二断熱管とを接続すれば、重複領域Ｒ１と非重複領域Ｒ２とのほぼ境界位置で、伝熱構造と断熱構造とに分けられた内部部材収納管２０を構築することができる。 The internal member storage pipe 20 in which the heat insulating structure and the heat transfer structure are mixed is obtained by connecting, for example, a first divided pipe having a heat transfer structure and a second divided pipe having a heat insulating structure. As the first divided tube having the heat transfer structure, for example, a single tube made of stainless steel can be used, and the length thereof is approximately the same as that of the outer heat insulating tube 30. On the other hand, as the second divided pipe having the heat insulating structure, the double pipe structure including the inner pipe and the outer pipe described in the first embodiment can be used. If these 1st heat insulation pipes and the 2nd heat insulation pipes are connected, the internal member storage pipe 20 divided into the heat transfer structure and the heat insulation structure is constructed at the substantially boundary position between the overlapping region R1 and the non-overlapping region R2. be able to.

＜実施形態５＞
実施形態１では、超電導ケーブル１とリターン管８とを並列させた超電導ケーブル線路１０１を説明した。これに対して、リターン管８を超電導ケーブル１と同様の構成を備える超電導ケーブルに置換することもできる。その場合、並列される両超電導ケーブルの内側冷媒の流路同士、および外側冷媒の流路同士を繋げれば良い。 <Embodiment 5>
In the first embodiment, the superconducting cable line 101 in which the superconducting cable 1 and the return pipe 8 are arranged in parallel has been described. On the other hand, the return pipe 8 can be replaced with a superconducting cable having the same configuration as the superconducting cable 1. In that case, it is only necessary to connect the flow paths of the inner refrigerant and the flow paths of the outer refrigerant of the superconducting cables arranged in parallel.

＜実施形態６＞
実施形態１では、二重流路構造を有する本発明の超電導ケーブル１同士を直列に接続することで超電導ケーブル線路１０１を構築した。これに対して、二重流路構造を有する本発明の超電導ケーブルと、一重流路構造を有する従来の超電導ケーブルと、を直列に接続した部分を有する超電導ケーブル線路とすることもできる。その場合、直列に接続される本発明の超電導ケーブルと従来の超電導ケーブルのケーブル内部部材同士は接続するが、冷媒流路同士は接続しないようにすると良い。 <Embodiment 6>
In Embodiment 1, the superconducting cable line 101 was constructed by connecting the superconducting cables 1 of the present invention having a double channel structure in series. On the other hand, it can also be set as the superconducting cable line which has the part which connected the superconducting cable of this invention which has a double flow path structure, and the conventional superconducting cable which has a single flow path structure in series. In that case, although the superconducting cable of the present invention connected in series and the cable internal members of the conventional superconducting cable are connected, it is preferable not to connect the refrigerant flow paths.

上記構成は、超電導ケーブル線路の布設経路において、冷却システムの設置スペースの確保が難しい難布設区間がある場合に好適である。例えば、超電導ケーブル線路の布設にあたって、難布設区間に本発明の超電導ケーブルを配置し、残りの区間に従来の超電導ケーブルを配置すると良い。 The above configuration is suitable when there is a difficult-to-install section in the installation path of the superconducting cable line in which it is difficult to secure the installation space for the cooling system. For example, when laying a superconducting cable line, the superconducting cable of the present invention may be arranged in a difficult laying section, and a conventional superconducting cable may be arranged in the remaining section.

＜実施形態７＞
実施形態１では、１条の超電導ケーブルに１心のケーブル内部部材を備える構成を説明した。これに対して、複数のケーブル内部部材を備える超電導ケーブルとすることができる。例えば、３心のケーブル内部部材を備える超電導ケーブルの場合、各ケーブル内部部材をそれぞれ内部部材収納管の内部に配置し、それら内部部材収納管を一括して外側断熱管の内部に配置すれば良い。 <Embodiment 7>
In the first embodiment, the configuration in which a single superconducting cable is provided with a single cable inner member has been described. On the other hand, it can be set as the superconducting cable provided with a some cable internal member. For example, in the case of a superconducting cable having three-core cable inner members, each cable inner member may be disposed inside the inner member storage tube, and these inner member storage tubes may be collectively disposed in the outer heat insulating tube. .

なお、本発明は、上述した実施形態に限定されるわけではなく、本発明の要旨を逸脱しない範囲において適宜変更して実施することが可能である。 Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the gist of the present invention.

本発明の超電導ケーブル、および本発明の超電導ケーブルを用いた超電導ケーブル線路は、例えば工場内の送電路に利用することができる。 The superconducting cable of the present invention and the superconducting cable line using the superconducting cable of the present invention can be used for a power transmission path in a factory, for example.

１０１超電導ケーブル線路
１超電導ケーブル（第一超電導ケーブル）
９０，９０’ ケーブル部
１０，１０’ ケーブル内部部材
１１フォーマ１２超電導導体１３電気絶縁層１４外側導体層
１５保護層
２０，２０’ 内部部材収納管
２１内管２２外管
２９内側流路接続部
３０，３０’ 外側断熱管
３１内管３２外管３３電気絶縁層
３９外側流路接続部
２０Ｃ内側冷媒
３０Ｃ外側冷媒
４０内側冷媒の循環冷却機構
４１リザーバタンク４２往路管４３復路管４４冷却システム
４５ポンプ
５０外側冷媒の循環冷却機構
５１リザーバタンク５２往路管５３復路管５４冷却システム
５５ポンプ
８リターン管８１内側流通管８２外側流通管
９１端末
Ｊ１〜Ｊ３接続部 101 Superconducting cable line 1 Superconducting cable (first superconducting cable)
90, 90 ′ Cable portion 10, 10 ′ Cable inner member 11 Former 12 Superconducting conductor 13 Electrical insulating layer 14 Outer conductor layer 15 Protective layer 20, 20 ′ Inner member storage tube 21 Inner tube 22 Outer tube 29 Inner flow path connection portion 30 , 30 'Outer heat insulation pipe 31 Inner pipe 32 Outer pipe 33 Electrical insulating layer 39 Outer flow path connection portion 20C Inner refrigerant 30C Outer refrigerant 40 Inner refrigerant circulation cooling mechanism 41 Reservoir tank 42 Outward pipe 43 Return pipe 44 Cooling system 45 Pump 50 Circulation cooling mechanism for outer refrigerant 51 Reservoir tank 52 Outward pipe 53 Return pipe 54 Cooling system 55 Pump 8 Return pipe 81 Inner flow pipe 82 Outer flow pipe 91 Terminals J1 to J3 Connection portion

Claims

超電導導体を有するケーブル内部部材を備える超電導ケーブルであって、
前記ケーブル内部部材、前記ケーブル内部部材が収納される内部部材収納管、および前記内部部材収納管が内部に収納される外側断熱管を備えるケーブル部と、
前記内部部材収納管の内部に循環され、前記ケーブル内部部材に備わる超電導導体を極低温に冷却する内側冷媒と、
前記外側断熱管の内部で、かつ前記内部部材収納管の外側に循環される外側冷媒と、を備え、
前記内部部材収納管が、前記外側断熱管よりも長く、それによって前記ケーブル部の長手方向に、前記内部部材収納管に前記外側断熱管が重複する重複領域と、前記内部部材収納管に前記外側断熱管が重複しない非重複領域と、が形成されている超電導ケーブル。 A superconducting cable comprising a cable inner member having a superconducting conductor,
A cable portion including the cable internal member, an internal member storage pipe in which the cable internal member is stored, and an outer heat insulating pipe in which the internal member storage pipe is stored;
An inner refrigerant that is circulated inside the inner member storage pipe and cools the superconducting conductor provided in the cable inner member to a cryogenic temperature;
An outer refrigerant circulated inside the outer heat insulating pipe and outside the inner member housing pipe,
The inner member storage tube is longer than the outer heat insulation tube, thereby overlapping in the longitudinal direction of the cable portion, the overlapping region where the outer heat insulation tube overlaps the inner member storage tube, and the outer surface of the inner member storage tube. A superconducting cable formed with non-overlapping areas where heat insulation pipes do not overlap.

前記内部部材収納管は、少なくとも第一分割管と、その第一分割管と異なる構造の第二分割管と、を組み合わせてなり、
前記外側断熱管の内部に、前記外側断熱管とほぼ同尺長の第一分割管が収納され、
前記重複領域と前記非重複領域とのほぼ境界位置で、前記第一分割管と前記第二分割管とが接続されている請求項１に記載の超電導ケーブル。 The internal member storage pipe is a combination of at least a first divided pipe and a second divided pipe having a structure different from that of the first divided pipe,
Inside the outer heat insulating tube, a first divided tube having the same length as the outer heat insulating tube is housed,
The superconducting cable according to claim 1, wherein the first divided pipe and the second divided pipe are connected at a substantially boundary position between the overlapping area and the non-overlapping area.

前記外側断熱管の内部に、前記外側断熱管よりも長尺の前記内部部材収納管の一部が配置されている請求項１に記載の超電導ケーブル。 The superconducting cable according to claim 1, wherein a part of the inner member housing pipe that is longer than the outer heat insulating pipe is disposed inside the outer heat insulating pipe.

前記内部部材収納管における少なくとも前記非重複領域に相当する部分は、断熱構造を備える請求項１〜３のいずれか一項に記載の超電導ケーブル。 The superconducting cable according to any one of claims 1 to 3, wherein at least a portion corresponding to the non-overlapping region in the internal member storage pipe includes a heat insulating structure.

前記内部部材収納管における前記重複領域に相当する部分は、伝熱構造を備える請求項４に記載の超電導ケーブル。 The superconducting cable according to claim 4, wherein a portion corresponding to the overlapping region in the internal member storage pipe has a heat transfer structure.

前記内部部材収納管の断熱性能が変更可能に構成されている請求項１〜５のいずれか一項に記載の超電導ケーブル。 The superconducting cable according to any one of claims 1 to 5, wherein the heat insulation performance of the internal member storage pipe is changeable.

直流送電に利用される請求項１〜６のいずれか一項に記載の超電導ケーブル。 The superconducting cable according to any one of claims 1 to 6, which is used for direct current power transmission.

交流送電に利用される請求項１〜６のいずれか一項に記載の超電導ケーブル。 The superconducting cable according to any one of claims 1 to 6, which is used for AC power transmission.

請求項１〜８のいずれか一項に記載の超電導ケーブルを少なくとも一部に備える超電導ケーブル線路。 A superconducting cable line comprising at least a part of the superconducting cable according to claim 1.

請求項１〜８のいずれか一項に記載の超電導ケーブルからなる第一超電導ケーブルと、
内側流通管、および前記内側流通管が内部に収納される外側流通管を備えるリターン管と、が並列して設けられる箇所を有し、
前記内側流通管が前記外側流通管よりも長く、それによってリターン管の長手方向に、前記内側流通管に前記外側流通管が重複する重複領域と、前記内側流通管に前記外側流通管が重複しない非重複領域と、が形成されており、
前記第一超電導ケーブルの内部部材収納管と、前記リターン管の内側流通管と、を繋げ、
前記第一超電導ケーブルの外側断熱管と、前記リターン管の外側流通管と、を繋げた請求項９に記載の超電導ケーブル線路。 A first superconducting cable comprising the superconducting cable according to any one of claims 1 to 8,
An inner distribution pipe, and a return pipe including an outer distribution pipe in which the inner distribution pipe is housed, and a portion provided in parallel;
The inner flow pipe is longer than the outer flow pipe, whereby in the longitudinal direction of the return pipe, an overlapping region where the outer flow pipe overlaps the inner flow pipe and the outer flow pipe does not overlap the inner flow pipe. A non-overlapping region is formed,
Connecting the internal member storage pipe of the first superconducting cable and the inner flow pipe of the return pipe,
The superconducting cable line according to claim 9, wherein an outer heat insulating pipe of the first superconducting cable and an outer circulation pipe of the return pipe are connected.

請求項１〜８のいずれか一項に記載の超電導ケーブルからなる第二超電導ケーブルと、
請求項１〜８のいずれか一項に記載の超電導ケーブルからなる第三超電導ケーブルと、
が並列して設けられる箇所を有し、
並列される前記第二超電導ケーブルと前記第三超電導ケーブルに備わる前記内部部材収納管同士、および前記外側断熱管同士を繋げた請求項９に記載の超電導ケーブル線路。 A second superconducting cable comprising the superconducting cable according to any one of claims 1 to 8,
A third superconducting cable comprising the superconducting cable according to any one of claims 1 to 8,
Are provided in parallel,
The superconducting cable track according to claim 9, wherein the inner member housing tubes and the outer heat insulating tubes provided in the second superconducting cable and the third superconducting cable arranged in parallel are connected.