JPH0221497B2 - - Google Patents
Info
- Publication number
- JPH0221497B2 JPH0221497B2 JP22493883A JP22493883A JPH0221497B2 JP H0221497 B2 JPH0221497 B2 JP H0221497B2 JP 22493883 A JP22493883 A JP 22493883A JP 22493883 A JP22493883 A JP 22493883A JP H0221497 B2 JPH0221497 B2 JP H0221497B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- refrigerator
- heat shield
- liquefaction
- expander
- 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.)
- Expired
Links
- 238000000034 method Methods 0.000 claims description 22
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- 239000007789 gas Substances 0.000 description 8
- 238000001816 cooling Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 239000003507 refrigerant Substances 0.000 description 5
- 238000005057 refrigeration Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 239000003595 mist Substances 0.000 description 4
- 238000010276 construction Methods 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000001174 ascending effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Description
【発明の詳細な説明】
本発明は極低温発生装置の熱侵入防止方法に関
し、特にHe液化冷凍機における熱シールド機構
部（以下熱シールド部という）への寒冷供給方法
の改良により設備コスト及びランニングコストの
低減を図る様にしたものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing heat intrusion into a cryogenic generator, and in particular to a method for supplying cold to a heat shield mechanism (hereinafter referred to as a heat shield) in a He liquefaction refrigerator, thereby reducing equipment costs and running costs. This is intended to reduce costs.
He液化冷凍機においては極低温部と室温部の
温度差が大きいため放射又は伝導により真空断熱
容器壁等を介して室温部から極低温部へ熱が侵入
するという構造上不可避の問題がある。そこで真
空断熱容器の室温部と極低温部との中間に熱シー
ルド部を設けて熱シールド部へ寒冷を供給するこ
とにより、極低温部への熱侵入をできる限り防止
することが行なわれている。例えば放射伝熱に関
していえば熱シールド部の温度を10℃Ｋに保持す
ると、極低温部への放射入熱量を室温部からの放
射入熱量の1/80程度に軽減できることが知られて
いる。ところで熱シールド部への寒冷供給方法と
してはこれまで提案又は更に実施されているもの
としては色々な具体例が挙げられるが、要約すれ
ば次の〜の方法に大別できる。 In Helium liquefaction refrigerators, there is an unavoidable structural problem in that the temperature difference between the cryogenic part and the room temperature part is large, so that heat intrudes from the room temperature part to the cryogenic part by radiation or conduction through the walls of the vacuum insulated container. Therefore, a heat shield section is provided between the room temperature section and the cryogenic section of the vacuum insulated container, and cold is supplied to the heat shield section in order to prevent heat from entering the cryogenic section as much as possible. . For example, with regard to radiant heat transfer, it is known that if the temperature of the heat shield section is maintained at 10 degrees K, the amount of radiant heat input to the cryogenic section can be reduced to about 1/80 of the amount of radiant heat input from the room temperature section. By the way, there are various specific examples of methods for supplying cold to the heat shield portion that have been proposed or further implemented, but they can be roughly divided into the following methods.
液体窒素を供給する方法：クロードサイクル
又はブライトンサイクルの熱力学的原理を応用
した極低温装置の典型例であるHe冷凍機装置
について図説すれば、次の通りである。第１図
はHe凍凍装置を例示する概略説明図で、He冷
凍装置１は、熱交換器５ａ〜５ｅ、膨張機７
ａ，７ｂ、JT弁６、熱シールド部１１等及び
これらを内蔵する真空断熱容器４より構成され
He液化冷凍機２、該冷凍機２入口側に連結さ
れた圧縮機３、該冷凍機２の出口側に連結され
た極低温環境部１０を中心に構成されている。
そしてHeガスは圧縮機３で加圧された後、第
１〜第５の熱交換器５ａ〜５ｅを降下（以下こ
の降下経路を「高圧側経路」という）して熱交
換を受けつつ膨張機７ａ，７ｂで発生した寒冷
により冷却され、更にJT弁６で大気圧近くま
で等エンタルピー膨張することにより一部液化
してHeの気液混合状態、即ちHeミストとなつ
た後、Heミスト供給管８から極低温環境部１
０内へ送られ、該環境部１０内におかれた被冷
却体９を極低温まで冷却する。尚極低温環境部
１０の具体的な用途としては、例えば極低温下
における超電導現象を利用した超電導コイルの
冷却を代表的に挙げることができる。 Method of supplying liquid nitrogen: A He refrigerator device, which is a typical example of a cryogenic device that applies the thermodynamic principle of the Claude cycle or Brighton cycle, is illustrated as follows. FIG. 1 is a schematic explanatory diagram illustrating a He freezing device, and the He freezing device 1 includes heat exchangers 5a to 5e, an expander 7,
a, 7b, a JT valve 6, a heat shield part 11, etc., and a vacuum insulated container 4 containing these.
It is mainly composed of a He liquefaction refrigerator 2, a compressor 3 connected to the inlet side of the refrigerator 2, and a cryogenic environment section 10 connected to the outlet side of the refrigerator 2.
After the He gas is pressurized by the compressor 3, it descends through the first to fifth heat exchangers 5a to 5e (hereinafter, this descending route is referred to as the "high pressure side route"), and is then transferred to the expander while undergoing heat exchange. It is cooled by the cold generated in 7a and 7b, and is further isenthalpically expanded to near atmospheric pressure in the JT valve 6, which partially liquefies He into a gas-liquid mixture state, that is, He mist, and then the He mist supply pipe 8 to cryogenic environment part 1
0 and cools the object to be cooled 9 placed in the environment section 10 to an extremely low temperature. A typical example of a specific use of the cryogenic environment section 10 is cooling of a superconducting coil utilizing the superconducting phenomenon at a cryogenic temperature.
さて極低温環境部１０内に存在する被冷却体
９の熱を奪つて気化したHeミストは、Heガス
となつて再びHe液化冷凍機２の熱交換器５ａ
〜５ｅを逆方向に上昇（以下この上昇経路を
「低圧側経路」という）し、対向流の高圧側経
路を流れるHeガスを冷却した後、自らは略常
温常圧のHeガスとなつて圧縮機３に戻る。そ
してHeガスがこの経路を循環することによつ
て極低温環境部１０内の被冷却体９を継続して
極低温に保つ様になつている。 Now, the He mist that has taken the heat of the object to be cooled 9 existing in the cryogenic environment section 10 and vaporized becomes He gas and returns to the heat exchanger 5a of the He liquefaction refrigerator 2.
5e in the opposite direction (hereinafter this ascending path will be referred to as the "low-pressure side path"), and after cooling the He gas flowing in the countercurrent high-pressure side path, it becomes He gas at approximately room temperature and normal pressure and is compressed. Return to machine 3. By circulating He gas through this path, the object to be cooled 9 in the cryogenic environment section 10 is continuously kept at a cryogenic temperature.
この様なHe液化冷凍機２において極低温部
に近い熱交換器５ｅ，５ｄ等は大きな表面積を
有するが故に真空断熱容器４の室温の壁から多
くの放射熱の侵入をうけ、液化冷凍能力の低下
を招き易い。そこで熱交換器５ｅ，５ｄと真空
断熱容器４の壁との間に熱シールド部１１を設
け、この熱シールド部１１に外部の液体窒素容
器１２より経路L3を通して液体窒素を供給す
ることにより低温に保持し、熱交換器５ｅ，５
ｄへの放射熱の侵入を防止している。 In such a He liquefaction refrigerator 2, the heat exchangers 5e, 5d, etc. near the cryogenic part have a large surface area, so they receive a lot of radiant heat from the room temperature wall of the vacuum insulation container 4, and the liquefaction refrigeration capacity is reduced. It is easy to cause a decline. Therefore, a heat shield part 11 is provided between the heat exchangers 5e, 5d and the wall of the vacuum insulation container 4, and liquid nitrogen is supplied to the heat shield part 11 from an external liquid nitrogen container 12 through the path L3 to reduce the temperature. and heat exchangers 5e, 5
This prevents radiant heat from entering d.
しかしこの場合は液体窒素の供給がなければ
He液化冷凍機２は所要の能力を発揮できない
欠点があり、設備費の増大と運転の自由度が制
約されるという問題がある。 However, in this case, if there is no liquid nitrogen supply,
The He liquefaction refrigerator 2 has the disadvantage that it cannot exhibit the required capacity, and there are problems in that the equipment cost increases and the degree of freedom of operation is restricted.
補助冷凍機を設けてこれにより寒冷を供給す
る方法：例えば第２図に示す様、第１図の構成
に対して真空断熱容器４内に補助熱交換器５ｆ
及び補助膨張機７ｃによりなる補助冷凍機２′
を新設すると共に、これらと真空断熱容器４外
に新設された補助圧縮機３′及び熱シールド部
１１とを経路L4，L5で連結する。該冷凍機
２′の運転により補助膨張機７ｃで発生した該
寒冷を熱シールド部１１へ供給することにより
熱侵入の防止を図つている。しかしこの場合も
補助冷凍機２′の並設によりHe液化冷凍機２の
構成が複雑且つ大型化し、設備コストの増加と
運転操作の複雑化を招く。 A method for supplying cold by providing an auxiliary refrigerator: For example, as shown in FIG. 2, for the configuration shown in FIG.
and an auxiliary refrigerator 2' consisting of an auxiliary expander 7c.
are newly installed, and these are connected to the auxiliary compressor 3' and the heat shield section 11, which are newly installed outside the vacuum insulation container 4, through paths L4 and L5 . By supplying the cold generated in the auxiliary expander 7c to the heat shield section 11 by operating the refrigerator 2', heat intrusion is prevented. However, in this case as well, the parallel arrangement of the auxiliary refrigerator 2' makes the configuration of the He liquefaction refrigerator 2 complicated and large, leading to increased equipment costs and complicated operation.
冷媒の一部を分岐し、真空断熱容器内の熱交
換器を通して冷却し、これにより寒冷を供給す
る方法：即ち第３図に示す様に圧縮機３で加圧
された冷媒（Heガス）の一部を分岐した後、
経路L6から補助熱交換器５ｆ、第２熱交換器
５ｂを通過する間に与えられた寒冷を熱シール
ド部１１へ供給し、次いで補助熱交換器５ｆ、
経路L7を通つて経路L1へ戻す方法である。し
かしこの方法においては補助熱交換器５ｆの新
設及び第２熱交換器５ｂの通路数増加による液
化冷凍機２の複雑且つ大型化を避けることはで
きず、又分岐した高圧の冷媒を余分に必要とす
るのみならず、その圧力を有効に利用せずに低
圧部へ戻すため圧縮動力の損失が大きくなると
いう欠点がある。 A method of branching a part of the refrigerant and cooling it through a heat exchanger in a vacuum insulated container, thereby supplying refrigeration: In other words, as shown in Fig. 3, the refrigerant (He gas) pressurized by the compressor 3 is After branching out some parts,
The cold given while passing through the auxiliary heat exchanger 5f and the second heat exchanger 5b from the path L6 is supplied to the heat shield part 11, and then the auxiliary heat exchanger 5f,
This is a method of returning to route L1 via route L7 . However, this method cannot avoid making the liquefaction refrigerator 2 more complicated and larger due to the new installation of the auxiliary heat exchanger 5f and the increase in the number of passages in the second heat exchanger 5b, and also requires extra branched high-pressure refrigerant. Not only that, but the pressure is returned to the low-pressure section without being effectively utilized, resulting in a large loss of compression power.
膨張機の排出管を熱シールド部と直接連結し
て寒冷を供給する方法：即ち第４図に示す様に
膨張機７ａ，７ｂからの排出ガスの全量を熱シ
ールド部１３，１４へ通して寒冷を供給する方
法であるが、この場合には排気管L8，L9の管
径を大きくして膨張機７ａ，７ｂの背圧損失が
極端に大きくなることを防がなければならな
い。従つて液化冷凍機２の容量が大きい場合に
はその排気管径が大きくなり過ぎ、冷却配管施
工の面で困難な問題が生じる。 A method of supplying cold by directly connecting the exhaust pipe of the expander to the heat shield part: In other words, as shown in FIG. However, in this case, the diameters of the exhaust pipes L 8 and L 9 must be increased to prevent the back pressure loss of the expanders 7a and 7b from becoming extremely large. Therefore, when the capacity of the liquefaction refrigerator 2 is large, the diameter of its exhaust pipe becomes too large, which causes difficult problems in the construction of cooling piping.
本発明は上記〜の欠点をすべて解消し、設
備コスト及びランニングコストの低減を図り得る
「熱シールド部への寒冷供給方法」を開発すべく
鋭意検討の結果完成したものであり、この様な本
発明の構成とは最も高温側に配置された膨張機の
排気管からのガスを分岐し、その一部を熱シール
ド部へ送つて所要の寒冷を供給したのち絞り部分
を通過した残部のガスと共に低圧側経路に合流さ
せる点に要旨を有するものである。 The present invention was completed as a result of intensive studies to develop a "method for supplying cold to a heat shield" that can eliminate all of the above-mentioned drawbacks and reduce equipment costs and running costs. The structure of the invention is to branch the gas from the exhaust pipe of the expander located on the highest temperature side, send a part of it to the heat shield part to supply the required cooling, and then, together with the remaining gas that passes through the throttle part. The gist of this is that it merges with the low pressure side path.
以下実施例図面に基づき本発明の構成及び作用
効果を説明するが、下記実施例は単に一代表例に
過ぎないものであつて、前・後記の趣旨に沿つて
適宜変更して実施し得ることは言うまでもない。 The configuration and effects of the present invention will be explained below based on the drawings of the embodiments. However, the embodiments below are merely representative examples, and the embodiments can be implemented with appropriate changes in accordance with the spirit of the above and below. Needless to say.
第５図は本発明の熱侵入防止方法を適用してな
るHe液化冷凍機を含むHe冷凍装置を例示する概
略説明図で、第１〜４図に示す従来例と基本的構
成は同一であり、同一構成のものには同一の符号
を付し、その説明は省略する。以下本実施例の特
徴とする構成を中心に説明する。まず最も高温部
に配置された膨張機７ａの排気管L10の途中に絞
り１５を設けると共に、該絞り１５の前後をバイ
パスする管を熱シールド部１６に直接連結せしめ
ている。即ち寒冷発生効率が最も高い膨張機７ａ
からの断熱膨張排気の保有寒冷のうちから絞り１
５によつて必要十分な量だけ熱シールド部１６へ
供給できるように構成されている。従つてこの様
に構成された液化冷凍機２においては、上記の
方法（第１図参照）に比べて液体窒素の供給を必
要とせず、従つて液化冷凍機２単独の運転を行な
うことができ、上記の方法の欠点を解消するこ
とができる。次に上記の方法（第２図参照）に
比べた場合、補助冷凍機２′を必要としないので
の方法の欠点も解消することができる。又上記
の方法（第３図参照）に比べて補助熱交換器５
ｆが不要であると共に第２熱交換器５ｂの通路数
を増加する必要もなく、又冷媒分岐方式故に問題
とされていた余分の高圧冷媒を無駄に減圧するこ
とによる動力損失を回避でき、の方法の欠点も
解消することができる。 FIG. 5 is a schematic explanatory diagram illustrating a He refrigeration system including a He liquefaction refrigerator to which the heat intrusion prevention method of the present invention is applied, and the basic configuration is the same as the conventional example shown in FIGS. 1 to 4. , those having the same configuration are given the same reference numerals, and the explanation thereof will be omitted. The following description will focus on the feature of this embodiment. First, a throttle 15 is provided in the middle of the exhaust pipe L10 of the expander 7a located at the highest temperature part, and a pipe that bypasses the front and rear of the throttle 15 is directly connected to the heat shield part 16. In other words, the expander 7a has the highest cold generation efficiency.
Adiabatic expansion exhaust from the holding cold out of the aperture 1
5 so that a necessary and sufficient amount can be supplied to the heat shield section 16. Therefore, the liquefaction refrigerator 2 configured in this manner does not require the supply of liquid nitrogen compared to the above method (see Figure 1), and therefore the liquefaction refrigerator 2 can be operated independently. , the drawbacks of the above methods can be overcome. Next, when compared with the above-mentioned method (see FIG. 2), the disadvantage of this method can also be overcome since the auxiliary refrigerator 2' is not required. Also, compared to the above method (see Figure 3), the auxiliary heat exchanger 5
f is unnecessary, there is no need to increase the number of passages in the second heat exchanger 5b, and power loss due to unnecessary pressure reduction of excess high-pressure refrigerant, which was a problem due to the refrigerant branching system, can be avoided. The shortcomings of the method can also be overcome.
更に上記の方法（第４図参照）に比べて、膨
張機７ａの排気管L10における圧力損失を一定に
保つた状態では、熱シールド部１６へ寒冷を供給
する配管を細くできる利点があり、冷却配管施工
の面で有利となる。 Furthermore, compared to the above method (see Fig. 4), there is an advantage that the pipe supplying cold to the heat shield section 16 can be made thinner while the pressure loss in the exhaust pipe L10 of the expander 7a is kept constant. This is advantageous in terms of cooling piping construction.
尚絞り１５の代わりに例えばエゼクターを設け
てもよく、要は熱シールド部１６に必要十分な寒
冷量だけ供給できる様に排気管L10の途中が絞ら
れた構成となつておればよい。又液化冷凍機２の
運転状況に応じて（例えば寒冷バランスの関係を
考慮して）上記の構成を更に膨張機７ｂの排気管
L11に組込むことも可能である。 Note that an ejector may be provided instead of the throttle 15, and the point is that the exhaust pipe L10 should be constricted in the middle so that the necessary and sufficient amount of cold can be supplied to the heat shield portion 16. Depending on the operating status of the liquefaction refrigerator 2 (for example, taking into consideration the cold balance), the above configuration may be further modified by adding the exhaust pipe of the expander 7b.
It is also possible to incorporate it into L 11 .
本発明の熱侵入防止方法は以上の様に構成した
ので、設備コスト及びランニングコストの点で非
常に有利なHe液化冷凍機を提供できることとな
つた。 Since the heat intrusion prevention method of the present invention is configured as described above, it has become possible to provide a He liquefaction refrigerator that is very advantageous in terms of equipment cost and running cost.
第１図〜第４図は従来の熱侵入防止方法を適用
してなるHe液化冷凍機を含むHe冷凍装置を示す
概略説明図、第５図は本発明の熱侵入防止方法を
適用してなるHe液化冷凍機を含むHe冷凍装置を
例示する概略説明図である。
１……He冷凍装置、２……He液化冷凍機、
２′……He補助冷凍機、３……圧縮機、３′……
補助圧縮機、４……真空断熱容器、５ａ〜５ｆ…
…熱交換器、６……JT弁、７ａ〜７ｃ……膨張
機、８……Heミスト供給管、９……被冷却体、
１０……極低温環境部、１１，１３，１４，１６
……熱シールド部、１５……絞り、L8，L9，
L10，L11……排気管。
1 to 4 are schematic explanatory diagrams showing a He refrigeration system including a He liquefaction refrigerator manufactured by applying the conventional method for preventing heat intrusion, and FIG. 1 is a schematic explanatory diagram illustrating a He refrigeration device including a He liquefaction refrigerator. FIG. 1...He refrigerator, 2...He liquefaction refrigerator,
2'... He auxiliary refrigerator, 3... Compressor, 3'...
Auxiliary compressor, 4... Vacuum insulation container, 5a to 5f...
... Heat exchanger, 6 ... JT valve, 7a to 7c ... Expander, 8 ... He mist supply pipe, 9 ... Cooled object,
10... Cryogenic environment department, 11, 13, 14, 16
... Heat shield part, 15 ... Aperture, L 8 , L 9 ,
L 10 , L 11 ...Exhaust pipe.
Claims (1)
の熱交換器、複数の膨張機及びジユールトムソン
膨張弁より構成されるHe液化冷凍機の前記熱シ
ールド機構部へ寒冷を供給することにより該He
液化冷凍機への熱侵入を防止する方法において、
最も高温側に配置された膨張機の低温ガス排気管
を分岐し、該膨張機で得られた低温ガスの一部を
前記熱シールド機構部へ送つて該機構部を冷却し
たのち絞り管路を通つた残部の低温ガス及び極低
温環境部からの戻りガスと合流させることを特徴
とするHe液化冷凍機の熱侵入防止方法。1. By supplying cold to the heat shield mechanism of a He liquefaction refrigerator, which is composed of a vacuum insulated container having a heat shield mechanism, multiple heat exchangers, multiple expanders, and a Joel-Thomson expansion valve, the He
In a method for preventing heat intrusion into a liquefaction refrigerator,
The low-temperature gas exhaust pipe of the expander placed on the highest temperature side is branched, and a part of the low-temperature gas obtained by the expander is sent to the heat shield mechanism to cool the mechanism, and then the throttle pipe is opened. A method for preventing heat intrusion into a He liquefaction refrigerator, characterized by combining the remaining low-temperature gas that has passed through and the return gas from a cryogenic environment section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22493883A JPS60117059A (en) | 1983-11-28 | 1983-11-28 | Method of preventing heat intrusion of he liquefying refrigerator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22493883A JPS60117059A (en) | 1983-11-28 | 1983-11-28 | Method of preventing heat intrusion of he liquefying refrigerator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60117059A JPS60117059A (en) | 1985-06-24 |
| JPH0221497B2 true JPH0221497B2 (en) | 1990-05-15 |
Family
ID=16821535
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22493883A Granted JPS60117059A (en) | 1983-11-28 | 1983-11-28 | Method of preventing heat intrusion of he liquefying refrigerator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60117059A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6291757A (en) * | 1985-10-16 | 1987-04-27 | 株式会社日立製作所 | Cryogenic refrigerating method and device |
| JPH0721357B2 (en) * | 1987-09-24 | 1995-03-08 | 株式会社日立製作所 | Cryogenic refrigerator |
-
1983
- 1983-11-28 JP JP22493883A patent/JPS60117059A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60117059A (en) | 1985-06-24 |
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