JPH0774018A - Current lead of superconducting apparatus - Google Patents
Current lead of superconducting apparatusInfo
- Publication number
- JPH0774018A JPH0774018A JP5220872A JP22087293A JPH0774018A JP H0774018 A JPH0774018 A JP H0774018A JP 5220872 A JP5220872 A JP 5220872A JP 22087293 A JP22087293 A JP 22087293A JP H0774018 A JPH0774018 A JP H0774018A
- Authority
- JP
- Japan
- Prior art keywords
- heat exchange
- exchange block
- lead
- current
- liquid nitrogen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 117
- 239000007788 liquid Substances 0.000 claims abstract description 66
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 56
- 239000001307 helium Substances 0.000 claims abstract description 35
- 229910052734 helium Inorganic materials 0.000 claims abstract description 35
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims abstract description 35
- 238000007710 freezing Methods 0.000 claims abstract description 24
- 230000008014 freezing Effects 0.000 claims abstract description 21
- 229910052751 metal Inorganic materials 0.000 claims abstract description 20
- 239000002184 metal Substances 0.000 claims abstract description 20
- 238000010438 heat treatment Methods 0.000 claims abstract description 12
- 230000002265 prevention Effects 0.000 claims abstract description 8
- 239000004020 conductor Substances 0.000 claims description 17
- 238000001816 cooling Methods 0.000 claims description 15
- 230000008018 melting Effects 0.000 claims description 7
- 238000002844 melting Methods 0.000 claims description 7
- 238000012544 monitoring process Methods 0.000 claims description 7
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 239000007789 gas Substances 0.000 abstract description 14
- 238000002347 injection Methods 0.000 abstract description 5
- 239000007924 injection Substances 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 2
- 238000002309 gasification Methods 0.000 abstract 1
- 238000010791 quenching Methods 0.000 description 7
- 230000008016 vaporization Effects 0.000 description 7
- 238000009834 vaporization Methods 0.000 description 7
- 230000020169 heat generation Effects 0.000 description 6
- 230000000171 quenching effect Effects 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 239000002887 superconductor Substances 0.000 description 3
- 229910000881 Cu alloy Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000009545 invasion Effects 0.000 description 2
- 230000000306 recurrent effect Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、極低温にある超電導
コイルに室温にある電源からの電流を通流する電流リー
ド、ことにリードの低温側に酸化物系超電導導体を用い
た電流リードの冷却構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current lead for passing a current from a power source at room temperature into a superconducting coil at a cryogenic temperature, and more particularly to a current lead using an oxide-based superconducting conductor on the low temperature side of the lead. Regarding cooling structure.
【０００２】[0002]
【従来の技術】超電導コイルは通常液体ヘリウム等の極
低温冷媒によって冷却されるため、液体窒素シールドや
高真空などで熱の浸入を阻止した断熱真空容器内に設け
られた液体ヘリウム容器に、液体ヘリウムに浸漬した状
態で収納される。電流リードは極低温に保持された超電
導電磁石としての超電導コイルに常温側から励磁電流を
通流するために設けられるものであり、リードで発生す
るジュール熱および常温側から極低温側に伝導により浸
入する熱を低減するために、電流リードの内部に気化し
た低温のヘリウムガスを流すよう構成したものが知られ
ている。この場合、電流リードの材料としては銅または
銅合金のような良導電性金属導体を用いるのが一般的で
あるが、その熱伝導率が高く浸入熱を低減する効果を期
待できないため、電流リードの侵入熱による液体ヘリウ
ムの気化量が超電導装置全体の液体ヘリウムの消費量の
大部分を占めるという問題があった。そこで、電流リー
ドを良導電性金属導体を用いた高温側リードと酸化物系
超電導導体を用いた低温側リードとの直列接続体とし、
両者の中間接続部に液体窒素冷却される良導電性金属容
器（熱交換ブロック）を設けて高温側リードからの侵入
熱を吸収し、かつ低温側リードを液体窒素およびヘリウ
ムガス冷却して液体窒素温度（７７．３５Ｋ）以下に保
ち、低温側リードを超電導状態に保持してジュ−ル発熱
を零にするとともに、その低熱伝導性を利用して液体ヘ
リウムの消費量を低減した電流リードが、例えば特開平
４−９４１０５号，特開平５−４８１５６号などで開示
されている。2. Description of the Related Art Since a superconducting coil is usually cooled by a cryogenic refrigerant such as liquid helium, liquid nitrogen is shielded in a liquid helium container provided in an adiabatic vacuum container in which heat is prevented from entering with a liquid nitrogen shield or high vacuum. It is stored while being immersed in helium. The current lead is provided to pass the exciting current from the room temperature side to the superconducting coil as a superconducting electromagnet, which is kept at a cryogenic temperature.The Joule heat generated in the lead and the penetration from the room temperature side to the cryogenic side by conduction. In order to reduce the generated heat, it is known that a vaporized low-temperature helium gas is caused to flow inside the current lead. In this case, it is common to use a good conductive metal conductor such as copper or copper alloy as the material of the current lead, but since the thermal conductivity is high and the effect of reducing the infiltration heat cannot be expected, the current lead cannot be expected. There is a problem that the amount of liquid helium vaporized by the heat of penetration of the liquid occupies most of the amount of liquid helium consumed by the entire superconducting device. Therefore, the current lead is a series connection body of a high temperature side lead using a good conductive metal conductor and a low temperature side lead using an oxide superconducting conductor,
A highly conductive metal container (heat exchange block) that is cooled with liquid nitrogen is provided at the intermediate connection between the two to absorb heat that has entered from the high temperature side lead and to cool the low temperature side lead with liquid nitrogen and helium gas. Keeping the temperature (77.35K) or less, keeping the low temperature side lead in the superconducting state to eliminate the Jule heat generation, and utilizing the low thermal conductivity, the current lead which reduces the consumption of liquid helium, For example, it is disclosed in JP-A-4-94105 and JP-A-5-48156.
【０００３】図４は従来の超電導装置の電流リードを模
式化して示す断面図である。図において、超電導コイル
１１は図示しない断熱真空容器内に設けられた液体ヘリ
ウム容器１２内に液体ヘリウムＨe に浸漬した状態で収
納され、超電導状態が保持される。電流リード１は銅ま
たは銅合金等の良導電性金属導体６からなる高温側リー
ド２と、酸化物系超電導導体からなる低温側リード３と
の直列接続体からなり、良導電性金属からなり液体窒素
Ｎ2 冷却される熱交換ブロック４を介して両者が直列接
続され、低温端子金具３Ａが超電導コイル１１に接続さ
れ、常温端子金具２Ａが図示しない電源に接続されるこ
とにより、超電導コイル１に電流が供給される。FIG. 4 is a schematic sectional view showing a current lead of a conventional superconducting device. In the figure, the superconducting coil 11 is housed in a liquid helium container 12 provided in an adiabatic vacuum container (not shown) in a state of being immersed in liquid helium He so that the superconducting state is maintained. The current lead 1 is composed of a series connection body of a high temperature side lead 2 made of a good conductive metal conductor 6 such as copper or a copper alloy and a low temperature side lead 3 made of an oxide-based superconducting conductor. Both are connected in series via the heat exchange block 4 cooled by nitrogen N 2 , the low temperature terminal metal fitting 3A is connected to the superconducting coil 11, and the room temperature terminal metal fitting 2A is connected to a power source (not shown). Electric current is supplied.
【０００４】また、高温側リード２は冷却フィン７を有
する良導電性金属導体６と、良導電性金属導体６との間
に冷却通路８を形成する筒状容器５とを備え、冷却通路
８の下端部が熱交換ブロック４内の液体窒素室に連通
し、上端部が排出口５Ａを介して外部に連通し、熱交換
ブロック内で気化した低温の窒素ガスＧＮ2 が冷却通路
８を介して外部に放出される。一方、低温側リード３は
液体ヘリウム容器１２に連通する筒状容器９で包囲さ
れ、液体ヘリウム容器１２内で気化した低温のヘリウム
ガスＧＨe が酸化物系超電導導体３の表面に沿って流れ
ることにより冷却される。従って、高温側リード２側の
侵入熱およびジュ−ル発熱は高温側リードの伝導によっ
て熱交換ブロック４に導かれ、熱交換ブロック内での液
体窒素の気化熱として吸収されるとともに、気化した低
温の窒素ガスが冷却フィンを有する冷却通路８を通って
排出される過程で高温側リードが冷却される。また、低
温側リード３はその上部側が液体窒素温度（約７７Ｋ）
に保持された熱交換ブロック４によって冷却され、下端
部側からは低温のヘリウムガスによって冷却されること
により、液体窒素温度以下に保持されて超電導状態とな
り、そのジュ−ル発熱が零になって低温端子金具３Ａ側
への侵入熱が減り、高価な液体ヘリウムの消費量が少な
く運転コストの低い超電導装置が得られる。The high temperature side lead 2 is provided with a good conductive metal conductor 6 having a cooling fin 7 and a cylindrical container 5 forming a cooling path 8 between the good conductive metal conductor 6 and the cooling path 8. Has a lower end communicating with the liquid nitrogen chamber in the heat exchange block 4, an upper end communicating with the outside through the discharge port 5A, and the low temperature nitrogen gas GN 2 vaporized in the heat exchange block passes through the cooling passage 8. Is released to the outside. On the other hand, the low temperature side lead 3 is surrounded by the cylindrical container 9 communicating with the liquid helium container 12, and the low temperature helium gas GH e vaporized in the liquid helium container 12 flows along the surface of the oxide superconducting conductor 3. Is cooled by. Therefore, the invasion heat and the Jule heat on the high temperature side lead 2 side are guided to the heat exchange block 4 by the conduction of the high temperature side lead, are absorbed as the vaporization heat of liquid nitrogen in the heat exchange block, and are vaporized at a low temperature. The high temperature side lead is cooled in the process in which the nitrogen gas is discharged through the cooling passage 8 having the cooling fin. Further, the low temperature side lead 3 has a liquid nitrogen temperature (about 77K) at its upper side.
The liquid is cooled by the heat exchange block 4 held by and is cooled by the low temperature helium gas from the lower end side to be kept at the liquid nitrogen temperature or lower to be in a superconducting state, and its Jule heat generation becomes zero. The heat entering the low-temperature terminal fitting 3A is reduced, the consumption of expensive liquid helium is small, and the superconducting device with low operating cost can be obtained.
【０００５】[0005]
【発明が解決しようとする課題】電流リードの低温側に
酸化物系超電導導体としてイットリウム，バリウムを含
むセラミック系高温超電導体を用いた場合、液体窒素温
度以下で超電導常態を示し、ジュ−ル熱が零になるとと
もに、その熱伝導率が銅の１／１００程度と小さく伝導
による侵入熱を大幅に低減できるので、液体ヘリウムの
消費量が少なく運転コストの低い超電導装置が得られ
る。また、高温側リードの熱伝導による侵入熱，および
電流により発生するジュ−ル熱（併せて侵入熱と呼ぶ）
を、熱交換ブロック中の液体窒素の気化熱として吸収
し、中間接続部の温度を液体窒素温度近くに保持できる
ので、低温側に酸化物系超電導導体を用いることによっ
て液体ヘリウムの気化量が減少し、これに伴って低温の
ヘリウムガスによる低温側リードの冷却効果が不十分に
なっても、この不足分を熱交換ブロックの液体窒素冷却
効果によって補償して低温側リードの超電導状態を安定
に保持し、信頼性の高い電流リードを備えた超電導装置
を得ることができる。When a ceramic high-temperature superconductor containing yttrium or barium is used as the oxide superconductor on the low temperature side of the current lead, the superconducting normal state is shown below the liquid nitrogen temperature, and the jule heat is generated. Becomes zero and the thermal conductivity thereof is as small as about 1/100 of that of copper, and the invasion heat due to conduction can be greatly reduced, so that a superconducting device with low consumption of liquid helium and low operating cost can be obtained. In addition, heat that penetrates due to heat conduction in the high temperature side lead and Jule heat that is generated by current (collectively called heat of penetration)
Is absorbed as the heat of vaporization of liquid nitrogen in the heat exchange block, and the temperature of the intermediate connection can be maintained near the temperature of liquid nitrogen, so the vaporization amount of liquid helium can be reduced by using the oxide superconductor on the low temperature side. However, even if the cooling effect of the low temperature side lead due to the low temperature helium gas becomes insufficient accordingly, this shortage is compensated by the liquid nitrogen cooling effect of the heat exchange block to stabilize the superconducting state of the low temperature side lead. It is possible to obtain a superconducting device having a current lead that is retained and has high reliability.
【０００６】ところが、超電導コイル側で発熱を伴う異
常現象，例えば超電導コイルが局部的に常電導状態に転
移するクエンチ現象が発生すると、その発熱によって液
体ヘリウムが多量に気化し、この低温のヘリウムガスに
よって低温側リードおよび熱交換ブロックが過冷却状態
となり、熱交換ブロックおよびその注入管部分で液体窒
素がその融点（６３Ｋ）以下に冷却されて固体化（凍
結）するという現象が発生する。液体窒素は固体化する
と、水におけると同様にその比重が液体状態のそれより
大きくなるという性質があるため、固体窒素の体膨張に
熱交換ブロックおよびその注入管部分が耐え切れずに破
損するという事態が予想される。また、熱交換ブロック
内の液体窒素が一旦凍結すると、高温側リード側からの
侵入熱によって固体窒素が融解するのに時間がかかり、
この間超電導コイルの再励磁が困難になるという問題も
発生する。However, when an abnormal phenomenon accompanied by heat generation on the superconducting coil side, for example, a quench phenomenon in which the superconducting coil locally changes to the normal conducting state occurs, a large amount of liquid helium is vaporized by the heat generation, and this low temperature helium gas is generated. As a result, the low temperature side lead and the heat exchange block are supercooled, and liquid nitrogen is cooled below its melting point (63K) and solidified (freezes) in the heat exchange block and its injection pipe portion. When liquid nitrogen solidifies, its specific gravity becomes larger than that of water in the same way as in water, so the heat exchange block and its injection pipe part will not be able to withstand the body expansion of solid nitrogen and will be damaged. The situation is expected. Also, once the liquid nitrogen in the heat exchange block freezes, it takes time for the solid nitrogen to melt due to the heat entering from the high temperature side lead side,
During this time, there arises a problem that it becomes difficult to re-excite the superconducting coil.
【０００７】この発明の目的は、液体窒素の凍結を防止
することにより、電流リードの損傷を防ぎ、かつ電流の
通流が常時可能な状態に保持することにある。An object of the present invention is to prevent freezing of liquid nitrogen, thereby preventing damage to the current leads and maintaining a state in which current can always flow.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決するため
に、この発明によれば、真空断熱容器の液体ヘリウム容
器内に液体ヘリウムに浸漬した状態で収納された超電導
コイルに外部より電流を通流する電流リードが、良導電
性金属導体からなる高温側リードと、酸化物系超電導導
体からなる低温側リードと、高温側リードと低温側リー
ドとを直列に導電接続しかつ冷却する，それ自身液体窒
素冷却される熱交換ブロックと、前記高温側リード内に
形成されて熱交換ブロック内で気化した低温の窒素ガス
により前記良導電性金属導体を冷却する冷却通路とを備
えたものにおいて、前記熱交換ブロック内の液体窒素の
凍結防止手段を備えてなるものとする。In order to solve the above-mentioned problems, according to the present invention, an electric current is externally applied to a superconducting coil housed in a liquid helium container of a vacuum heat insulation container while being immersed in the liquid helium. The current lead to be flowed is such that the high temperature side lead made of a good conductive metal conductor, the low temperature side lead made of an oxide superconducting conductor, and the high temperature side lead and the low temperature side lead are conductively connected in series and cooled. A liquid nitrogen-cooled heat exchange block, and a cooling passage formed in the high temperature side lead for cooling the good conductive metal conductor by low temperature nitrogen gas vaporized in the heat exchange block, It shall be provided with a means for preventing freezing of liquid nitrogen in the heat exchange block.
【０００９】凍結防止手段が埋込電気ヒ−タを良導電性
金属板中に埋設した加熱板からなり、この加熱板と熱交
換ブロックとを密接して一体化してなるものとする。凍
結防止手段が埋込電気ヒ−タからなり、この埋込電気ヒ
−タを熱交換ブロックの母材中に埋設してなるものとす
る。凍結防止手段が埋込電気ヒ−タと、熱交換ブロック
温度の監視センサと、検出温度が窒素の融点近傍にまで
低下したとき前記埋込ヒ−タに加熱を指令する制御回路
とからなるものとする。The antifreezing means is composed of a heating plate in which an embedded electric heater is embedded in a metal plate of good conductivity, and the heating plate and the heat exchange block are closely integrated with each other. The antifreezing means is composed of an embedded electric heater, and the embedded electric heater is embedded in the base material of the heat exchange block. The antifreezing means includes an embedded electric heater, a heat exchange block temperature monitoring sensor, and a control circuit for instructing the embedded heater to heat when the detected temperature drops to near the melting point of nitrogen. And
【００１０】[0010]
【作用】この発明において、高温側リードと低温側リー
ドとを直列に導電接続しかつ冷却するそれ自身液体窒素
室冷却される熱交換ブロックに、熱交換ブロック内の液
体窒素の凍結防止手段を設けるよう構成したことによ
り、超電導コイルでクエンチが発生して低温のヘリウム
ガスの気化量が急増したとき、凍結防止手段の発熱によ
って熱交換ブロックおよび液体窒素の注入口内の液体窒
素の凍結を防止できるので、液体窒素が凍結，膨張する
ことにより発生する熱交換ブロックおよび液体窒素の注
入口の損傷、および凍結した窒素が自然融解する迄の
間、電流の再通流が制約されるなどの従来の問題点を排
除し、電流リードを電流の通流が常時可能な状態に保持
する機能が得られる。According to the present invention, the heat exchange block, which electrically connects the high temperature side lead and the low temperature side lead in series and cools itself in the liquid nitrogen chamber, is provided with the antifreezing means of the liquid nitrogen in the heat exchange block. With this configuration, when quenching occurs in the superconducting coil and the vaporization amount of low-temperature helium gas increases rapidly, it is possible to prevent freezing of liquid nitrogen in the heat exchange block and the inlet of liquid nitrogen by the heat generation of the antifreezing means. , Conventional problems such as damage to the heat exchange block and liquid nitrogen inlet caused by freezing and expansion of liquid nitrogen, and restriction of re-current flow until the frozen nitrogen spontaneously melts The point is eliminated, and the function of keeping the current lead in a state where the current can always flow is obtained.
【００１１】また、凍結防止手段を良導電性金属板中に
埋込電気ヒ−タを埋設した加熱板とし、この加熱板と熱
交換ブロックとを密接して一体化するよう構成すれば、
簡素な構成の凍結防止手段により、超電導コイルでクエ
ンチが発生して低温のヘリウムガスの気化量が急増した
とき、凍結防止手段の発熱によって熱交換ブロックおよ
び液体窒素の注入口内の液体窒素の凍結を防止できるの
で、液体窒素が凍結，膨張することにより発生する熱交
換ブロックおよび液体窒素の注入口の損傷、および凍結
した窒素が自然融解する迄の間、電流の再通流が制約さ
れるなどの従来の問題点を排除し、電流リードを電流の
通流が常時可能な状態に保持する機能が得られる。Further, if the antifreezing means is a heating plate in which an embedded electric heater is embedded in a metal plate of good conductivity, and the heating plate and the heat exchange block are closely integrated,
When the quenching occurs in the superconducting coil and the vaporization amount of low-temperature helium gas increases rapidly, the antifreezing means with a simple structure heats the antifreezing means to freeze the liquid nitrogen in the heat exchange block and the liquid nitrogen inlet. Since it can be prevented, damage to the heat exchange block and the liquid nitrogen inlet caused by freezing and expansion of liquid nitrogen, and restriction of recurrent flow of electric current until the frozen nitrogen spontaneously melts can be prevented. It is possible to obtain the function of eliminating the conventional problems and keeping the current lead in a state where the current can always flow.
【００１２】さらに、凍結防止手段を埋込電気ヒ−タと
し、この埋込電気ヒ−タを熱交換ブロックの母材中に埋
設するよう構成すれば、より簡素な構成の凍結防止手段
により、上記と同様の機能が得られる。一方、凍結防止
手段を埋込電気ヒ−タと、熱交換ブロック温度の監視セ
ンサと、検出温度が窒素の融点近傍にまで低下したとき
埋込ヒ−タの加熱を指令する制御回路とで構成すれば、
クエンチの発生によるヘリウムガスの発生量の増加を、
熱交換ブロック温度の低下として温度監視センサが捕ら
え、その温度が窒素の融点近傍にまで低下したことを制
御回路が検知して埋込電気ヒ−タの加熱を指令するの
で、自動化することによって凍結防止手段の保護動作の
信頼性を向上し、液体窒素の凍結を確実に防止する機能
が得られる。Furthermore, if the freezing prevention means is an embedded electric heater, and this embedded electric heater is embedded in the base material of the heat exchange block, the antifreezing means having a simpler structure can be used. The same function as above can be obtained. On the other hand, the anti-freezing means is composed of an embedded electric heater, a heat exchange block temperature monitoring sensor, and a control circuit for instructing the heating of the embedded heater when the detected temperature drops to near the melting point of nitrogen. if,
The increase in the amount of helium gas generated due to the occurrence of quench,
As the temperature of the heat exchange block decreases, the temperature monitoring sensor catches it, and the control circuit detects that the temperature has dropped to near the melting point of nitrogen and commands the heating of the embedded electric heater, so it is frozen by automation. The function of improving the reliability of the protection operation of the prevention means and reliably preventing the freezing of the liquid nitrogen can be obtained.
【００１３】[0013]
【実施例】以下、この発明を実施例に基づいて説明す
る。図１はこの発明の実施例になる超電導装置とその電
流リードを模式化して示す断面図であり、従来技術と同
じ構成部分には同一参照符号を付すことにより、重複し
た説明を省略する。図において、凍結防止手段２１は埋
込電気ヒ−タ２２を熱伝導性のよい金属板２３中に埋設
した加熱板として構成され、熱交換ブロック４の下面に
密着するよう取り付けられる。EXAMPLES The present invention will be described below based on examples. FIG. 1 is a cross-sectional view schematically showing a superconducting device and a current lead thereof according to an embodiment of the present invention. The same components as those of the conventional art are designated by the same reference numerals, and a duplicate description will be omitted. In the figure, the antifreezing means 21 is configured as a heating plate in which an embedded electric heater 22 is embedded in a metal plate 23 having good thermal conductivity, and is attached so as to be in close contact with the lower surface of the heat exchange block 4.
【００１４】このように構成された凍結防止手段２１を
有する電流リード１において、超電導コイル１１でクエ
ンチが発生して低温のヘリウムガスＧＨ2 の気化量が急
増したとき埋込電気ヒ−タ２２に通電すれば、凍結防止
手段２１の発熱によって熱交換ブロック４および液体窒
素の注入口４Ａ内の液体窒素の凍結を防止できるので、
液体窒素が凍結，膨張することによって発生する電流リ
ードの損傷，および電流の再通流に与える制約を排除
し、電流リードを電流の通流が常時可能な状態に保持で
きる利点が得られる。なお、液体ヘリウム容器１２には
バイパス通路１２Ｂを設け、低温側リード３側の筒状容
器９に流れる低温のヘリウムガス流量を制限するよう構
成してもよい。In the current lead 1 having the anti-freezing means 21 constructed as described above, when the quenching occurs in the superconducting coil 11 and the vaporization amount of the low-temperature helium gas GH 2 rapidly increases, the embedded electric heater 22 is provided. When the power is turned on, it is possible to prevent the freezing of the liquid nitrogen in the heat exchange block 4 and the liquid nitrogen inlet 4A by the heat generation of the antifreezing means 21,
There is an advantage that the current lead can be maintained in a state where the current can always flow, by eliminating the damage on the current lead caused by the freezing and expansion of the liquid nitrogen and the restriction on the current reflow. The liquid helium container 12 may be provided with a bypass passage 12B so as to limit the flow rate of the low-temperature helium gas flowing into the tubular container 9 on the low temperature side lead 3 side.
【００１５】図２はこの発明の異なる実施例になる超電
導装置とその電流リードを模式化して示す断面図であ
り、凍結防止手段としての埋込ヒ−タ２２が熱交換ブロ
ック４の母材中に直接埋設された点が前述の実施例と異
なり、凍結防止手段をより簡素に構成して前記実施例と
同様に目的を達成することができる。図３はこの発明の
他の実施例になる超電導装置とその電流リードを模式化
して示す断面図であり、凍結防止手段３１を埋込電気ヒ
−タ２２と、熱交換ブロック温度の監視センサ３２と、
検出温度が窒素の融点（固体化開始温度）近傍にまで低
下したとき埋込ヒ−タ２２に加熱を指令する制御回路３
３とで構成すれば、クエンチの発生によるヘリウムガス
の発生量の増加を、熱交換ブロック４の温度の低下とし
て温度監視センサ３２が捕らえ、その温度が窒素の融点
近傍にまで低下したことを制御回路３３が検知して埋込
電気ヒ−タに加熱を指令するので、自動化することによ
って凍結防止手段の動作の信頼性が向上し、液体窒素が
凍結することにより発生する電流リードの損傷，および
電流の再通流に与える制約を未然に排除し、電流の通流
を常時可能な状態に保持できる電流リードを得ることが
できる。FIG. 2 is a schematic sectional view showing a superconducting device and its current lead according to another embodiment of the present invention. The embedded heater 22 as the antifreezing means is in the base material of the heat exchange block 4. Unlike the above-mentioned embodiment in that it is directly embedded in the structure, the antifreezing means can be configured more simply to achieve the same purpose as in the above-described embodiment. FIG. 3 is a sectional view schematically showing a superconducting device and a current lead thereof according to another embodiment of the present invention. An anti-freezing means 31 is embedded in an electric heater 22, and a heat exchange block temperature monitoring sensor 32 is provided. When,
A control circuit 3 for instructing the embedded heater 22 to heat when the detected temperature falls near the melting point of nitrogen (solidification start temperature).
If configured with 3, the temperature monitoring sensor 32 catches an increase in the amount of helium gas generated due to the occurrence of quench as a decrease in the temperature of the heat exchange block 4, and controls that the temperature has decreased to near the melting point of nitrogen. Since the circuit 33 detects and commands the embedded electric heater to heat, the automation improves the reliability of the operation of the antifreezing means, and damages of the current lead caused by freezing of the liquid nitrogen, and It is possible to obtain a current lead that can keep the current flow in a state where the current flow can be always performed by removing the restriction on the current reflow.
【００１６】[0016]
【発明の効果】この発明は前述のように、高温側リード
と低温側リードとを直列に導電接続しかつ冷却するそれ
自身液体窒素冷却される熱交換ブロックに、熱交換ブロ
ック内の液体窒素の凍結防止手段として例えば良導電性
金属板中に埋込電気ヒ−タを埋設した加熱板を設けるよ
う構成した。その結果、超電導コイルでクエンチが発生
して低温のヘリウムガスの気化量が急増したとき、凍結
防止手段の発熱によって熱交換ブロックの温度の低下を
防ぎ、液体窒素の凍結を防止できるので、従来、液体窒
素が凍結，膨張することによって発生した熱交換ブロッ
クおよび液体窒素の注入口の損傷、および凍結した窒素
が自然融解する迄の間、電流の再通流が制約されるなど
の問題点を排除し、電流の通流を常時可能な状態に安定
して保持できる電流リードを備えた超電導装置を提供す
ることができる。As described above, according to the present invention, the heat exchange block which is liquid nitrogen cooled by itself electrically connecting and cooling the high temperature side lead and the low temperature side lead is connected to the liquid nitrogen in the heat exchange block. As a means for preventing freezing, for example, a heating plate in which an embedded electric heater is embedded in a metal plate having good conductivity is provided. As a result, when quenching occurs in the superconducting coil and the vaporization amount of low-temperature helium gas increases rapidly, the temperature of the heat exchange block can be prevented from lowering due to the heat generated by the antifreezing means, and the freezing of liquid nitrogen can be prevented. Eliminates problems such as damage to the heat exchange block and liquid nitrogen injection port caused by freezing and expansion of liquid nitrogen, and restriction of recurrent flow of electric current until the frozen nitrogen spontaneously melts. However, it is possible to provide a superconducting device provided with a current lead capable of stably maintaining a current flow state at all times.
【図１】この発明の実施例になる超電導装置とその電流
リードを模式化して示す断面図FIG. 1 is a sectional view schematically showing a superconducting device and its current lead according to an embodiment of the present invention.
【図２】この発明の異なる実施例になる超電導装置とそ
の電流リードを模式化して示す断面図FIG. 2 is a sectional view schematically showing a superconducting device according to another embodiment of the present invention and its current lead.
【図３】この発明の他の実施例になる超電導装置とその
電流リードを模式化して示す断面図FIG. 3 is a sectional view schematically showing a superconducting device and its current lead according to another embodiment of the present invention.
【図４】従来の超電導装置の電流リードを模式化して示
す断面図FIG. 4 is a sectional view schematically showing a current lead of a conventional superconducting device.
１ 電流リード ２ 高温側リード ３ 低温側リード（酸化物系超電導導体） ４ 熱交換ブロック ４Ａ 液体窒素の注入口 ５ 筒状容器 ５Ａ 排出口 ６ 良導電性金属導体 ７ 冷却フィン ８ 冷却通路 ９ 筒状容器（低温側リード側） １１ 超電導コイル １２ 液体ヘリウム容器 ２１ 凍結防止手段（加熱板） ２２ 埋込ヒ−タ ２３ 良熱伝導性金属板 ３１ 凍結防止手段 ３２ 温度監視センサ ３３ 制御回路 ＧＨe 低温のヘリウムガス ＧＮ2 低温の窒素ガス1 Current Lead 2 High Temperature Side Lead 3 Low Temperature Side Lead (Oxide Superconducting Conductor) 4 Heat Exchange Block 4A Liquid Nitrogen Injection Port 5 Cylindrical Container 5A Discharge Port 6 Good Conductive Metal Conductor 7 Cooling Fin 8 Cooling Passage 9 Cylindrical Container (low temperature side lead side) 11 Superconducting coil 12 Liquid helium container 21 Freezing prevention means (heating plate) 22 Embedded heater 23 Good heat conductive metal plate 31 Freezing prevention means 32 Temperature monitoring sensor 33 Control circuit GHe Low temperature helium Gas GN 2 Low temperature nitrogen gas
Claims (4)
ヘリウムに浸漬した状態で収納された超電導コイルに外
部より電流を通流する電流リードが、良導電性金属導体
からなる高温側リードと、酸化物系超電導導体からなる
低温側リードと、高温側リードと低温側リードとを直列
に導電接続しかつ冷却する，それ自身液体窒素冷却され
る熱交換ブロックと、前記高温側リード内に形成されて
熱交換ブロック内で気化した低温の窒素ガスにより前記
良導電性金属導体を冷却する冷却通路とを備えたものに
おいて、前記熱交換ブロック内の液体窒素の凍結防止手
段を備えてなることを特徴とする超電導装置の電流リー
ド。1. A current lead for passing an electric current from the outside to a superconducting coil housed in a liquid helium container in a vacuum heat-insulated container immersed in the liquid helium, and a high temperature side lead made of a good conductive metal conductor, A low temperature side lead made of an oxide-based superconducting conductor, a high temperature side lead and a low temperature side lead are electrically connected in series and cooled, and a heat exchange block cooled by liquid nitrogen itself is formed in the high temperature side lead. And a cooling passage for cooling the good conductive metal conductor by the low-temperature nitrogen gas vaporized in the heat exchange block, characterized in that it comprises means for preventing freezing of liquid nitrogen in the heat exchange block. And the current lead of the superconducting device.
金属板中に埋設した加熱板からなり、この加熱板と熱交
換ブロックとを密接して一体化してなることを特徴とす
る請求項１記載の超電導装置の電流リード。2. The antifreezing means comprises a heating plate in which an embedded electric heater is embedded in a metal plate having good conductivity, and the heating plate and the heat exchange block are closely integrated with each other. The current lead of the superconducting device according to claim 1.
この埋込電気ヒ−タを熱交換ブロックの母材中に埋設し
てなることを特徴とする請求項１記載の超電導装置の電
流リード。3. Freezing prevention means comprises an embedded electric heater,
2. The current lead of a superconducting device according to claim 1, wherein the embedded electric heater is embedded in the base material of the heat exchange block.
ブロック温度の監視センサと、検出温度が窒素の融点近
傍にまで低下したとき前記埋込ヒ−タに加熱を指令する
制御回路とからなることを特徴とする請求項１記載の超
電導装置の電流リード。4. An embedded electric heater, a heat exchange block temperature monitoring sensor, and a control for instructing the embedded heater to heat when the detected temperature drops near the melting point of nitrogen. The current lead of a superconducting device according to claim 1, wherein the current lead comprises a circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5220872A JPH0774018A (en) | 1993-09-06 | 1993-09-06 | Current lead of superconducting apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5220872A JPH0774018A (en) | 1993-09-06 | 1993-09-06 | Current lead of superconducting apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0774018A true JPH0774018A (en) | 1995-03-17 |
Family
ID=16757865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5220872A Pending JPH0774018A (en) | 1993-09-06 | 1993-09-06 | Current lead of superconducting apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0774018A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1261113A2 (en) * | 2001-05-15 | 2002-11-27 | General Electric Company | High temperature superconducting rotor power leads |
| KR20140040418A (en) * | 2012-09-26 | 2014-04-03 | 한국전력공사 | Apparatus for cooling current leads of superconducting machine |
-
1993
- 1993-09-06 JP JP5220872A patent/JPH0774018A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1261113A2 (en) * | 2001-05-15 | 2002-11-27 | General Electric Company | High temperature superconducting rotor power leads |
| EP1261113A3 (en) * | 2001-05-15 | 2002-12-11 | General Electric Company | High temperature superconducting rotor power leads |
| CN1311616C (en) * | 2001-05-15 | 2007-04-18 | 通用电气公司 | Power source wire for high-temp. superconductive rotor |
| CZ301682B6 (en) * | 2001-05-15 | 2010-05-26 | General Electric Company | Power leads of high temperature superconducting rotor |
| KR20140040418A (en) * | 2012-09-26 | 2014-04-03 | 한국전력공사 | Apparatus for cooling current leads of superconducting machine |
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