JPH0427491B2 - - Google Patents
Info
- Publication number
- JPH0427491B2 JPH0427491B2 JP15332787A JP15332787A JPH0427491B2 JP H0427491 B2 JPH0427491 B2 JP H0427491B2 JP 15332787 A JP15332787 A JP 15332787A JP 15332787 A JP15332787 A JP 15332787A JP H0427491 B2 JPH0427491 B2 JP H0427491B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure side
- pressure
- pipe
- electric heater
- liquid level
- 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
- 239000007788 liquid Substances 0.000 claims description 29
- 239000003507 refrigerant Substances 0.000 claims description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 18
- 239000007789 gas Substances 0.000 description 11
- 229910052757 nitrogen Inorganic materials 0.000 description 9
- 239000004065 semiconductor Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000896 Manganin Inorganic materials 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- GPWDPLKISXZVIE-UHFFFAOYSA-N cyclo[18]carbon Chemical class C1#CC#CC#CC#CC#CC#CC#CC#CC#C1 GPWDPLKISXZVIE-UHFFFAOYSA-N 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 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
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910001120 nichrome Inorganic materials 0.000 description 1
- 238000007665 sagging Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、冷媒液面計に係り、特に液体窒素や
液体ヘリウムフロン系冷媒に使用するのに好適な
冷媒液面計に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigerant level gauge, and particularly to a refrigerant level gauge suitable for use with liquid nitrogen or liquid helium fluorocarbon type refrigerants.
従来、液体窒素等の極低温冷媒の貯槽の液面を
計測する方法として、貯槽の底部に高圧側配管
を、上部気相部に低圧側配管を開口せしめて、そ
の圧力差を測り、冷媒のヘツドを求める方法があ
る。例えば、実開昭62−12824号公報に記載のよ
うに、電気ヒータを高圧側取入口に設けた例があ
る。
Conventionally, the method of measuring the liquid level in a storage tank for cryogenic refrigerants such as liquid nitrogen is to open a high-pressure side pipe at the bottom of the storage tank and a low-pressure side pipe at the upper gas phase, measure the pressure difference, and measure the level of the refrigerant. There is a way to find the head. For example, as described in Japanese Utility Model Application Publication No. 62-12824, there is an example in which an electric heater is provided at the high-pressure side intake.
しかしながら、上記従来技術では、熱損失を小
さくするため高圧側配管の径を小さくすると、高
圧側取入口に設けたヒータにより発生した蒸気が
入口を塞ぎ、高圧側配管内に流入した液体が蒸気
と入れ替わることなく管内に捕促されてしまうこ
とがあつた。この場合、正しい液面の指示は得ら
なかつた。
However, in the above conventional technology, when the diameter of the high-pressure side piping is made small to reduce heat loss, the steam generated by the heater installed at the high-pressure side intake block the inlet, and the liquid flowing into the high-pressure side piping turns into steam. In some cases, they were trapped inside the pipe without being replaced. In this case, no indication of the correct liquid level was obtained.
本発明の目的は、このような問題点を除き、常
に正しい液面指示を得ることのできる冷媒液面計
を得ることにある。 An object of the present invention is to eliminate such problems and provide a refrigerant level gauge that can always provide correct level indications.
上記目的は、高圧側配管のある一定区間にわた
り、管の内側又は外側に電気ヒータを挿入又は巻
回し、液面測定時にのみこのヒータを加熱するこ
とにより達成される。
The above object is achieved by inserting or winding an electric heater inside or outside the high-pressure pipe over a certain section, and heating this heater only when measuring the liquid level.
本発明においては、高圧側配管を真空断熱二重
管とし、ヒータ挿入区間をこの断熱区間長とし、
低圧側配管を高圧側配管と同軸とし、圧力差は半
導体差圧変換器を用いるのが望ましい。 In the present invention, the high pressure side piping is a vacuum insulated double pipe, the heater insertion section is the length of this insulation section,
It is desirable that the low-pressure side piping be coaxial with the high-pressure side piping, and that a semiconductor differential pressure converter be used for the pressure difference.
断熱された高圧側配管は、液面計測時は電気ヒ
ータによつて加熱され、内部に外圧によつて侵入
したりあるいは管壁が冷やされて凝縮してできた
液体がこの熱で気化して、配管の外に押し出され
る。それにより、高圧側配管は全長にわたり気相
のみとなり、正しいヘツドを計測することができ
る。
The insulated high-pressure side piping is heated by an electric heater when measuring the liquid level, and this heat may cause liquid to enter the interior due to external pressure or to condense as the pipe wall cools. , pushed out of the pipe. As a result, the entire length of the high-pressure side piping is filled with only the gas phase, making it possible to measure the correct head.
以下、本発明の一実施例を第１図により説明す
る。１は、液体窒素２を収納する断熱された貯
槽、３は液体窒素２を入れたり、その蒸発したガ
ス相４を外に出したり、液面計５を挿入したりす
るポートである。液面計５は外筒６をポート３に
挿入し、Ｏリング７、ワツシヤー８、押え金具９
により、密封固定されている。１０は、逆止弁１
１の入つたガス抜き口である。外筒６は、孔１２
を有する固定金具１３により、真空ケース１４に
固定されている。真空ケース１４の内側には高圧
側の圧力管１５が貫通している。圧力管１５とし
ては、薄肉のステンレス鋼管が望ましく、内径１
〜５mmとするのがよく、その内側には、電気ヒー
タ線１６を入れる。電気ヒータ線１６は、電気絶
縁したマンガニン線やニクロム線で、直径0.2〜
１mmが望ましい。圧力管１５は、真空ケース１４
の上部の一部拡大した部分で屈曲部１７を形成
し、真空ケース１４と圧力管１５に生ずる熱歪み
の差を吸収する。真空ケース１４の底部には、活
性炭１８を少量入れておき、真空度劣化の原因と
なる放出ガスを吸着させる。１９は真空封じ部
で、内部は長期的に真空を維持できる。電気ヒー
タ線１６は上部のハーメチツク端子２０と下部の
圧力管先端２１に半田付けされる。また、圧力管
１５の上端は半導体式差圧変換器２２の高圧側管
２３に接続し、低圧側管２４は、外筒６中に開放
する。半導体式差圧変換器２２のリード端子２５
からのリード線２６、ハーメチツク端子２０から
のリード線２７及び、電気ヒータ線１６の他端の
電極に相当する圧力管１５からのリード線２８は
すべて、ハーメチツク・コネクタ２９に絶縁して
固定されたピン３０に接続してある。ハーメチツ
ク・コネクタ２９は、Ｏリング３１により外筒６
に気密に固定されている。
An embodiment of the present invention will be described below with reference to FIG. 1 is an insulated storage tank for storing liquid nitrogen 2; 3 is a port through which the liquid nitrogen 2 is put in, the evaporated gas phase 4 is taken out, and a liquid level gauge 5 is inserted. For the liquid level gauge 5, insert the outer cylinder 6 into the port 3, and attach the O-ring 7, washer 8, and presser fitting 9.
It is sealed and fixed. 10 is check valve 1
It is a gas vent with 1 in it. The outer cylinder 6 has a hole 12
It is fixed to the vacuum case 14 by a fixing fitting 13 having a shape. A pressure pipe 15 on the high pressure side passes through the inside of the vacuum case 14. As the pressure pipe 15, a thin-walled stainless steel pipe is preferable, and the inner diameter is 1
It is preferable to set it to ~5 mm, and the electric heater wire 16 is inserted inside it. The electric heater wire 16 is an electrically insulated manganin wire or nichrome wire, and has a diameter of 0.2~
1mm is desirable. The pressure pipe 15 is connected to the vacuum case 14
A bent portion 17 is formed at a partially enlarged upper portion of the tube, and absorbs the difference in thermal strain occurring between the vacuum case 14 and the pressure tube 15. A small amount of activated carbon 18 is placed at the bottom of the vacuum case 14 to adsorb released gases that cause deterioration of the degree of vacuum. Reference numeral 19 denotes a vacuum sealing section, which can maintain a vacuum inside for a long period of time. The electric heater wire 16 is soldered to an upper hermetic terminal 20 and a lower pressure tube tip 21. Further, the upper end of the pressure pipe 15 is connected to a high pressure side pipe 23 of a semiconductor type differential pressure converter 22, and a low pressure side pipe 24 is opened into the outer cylinder 6. Lead terminal 25 of semiconductor differential pressure converter 22
The lead wire 26 from the hermetic terminal 20, the lead wire 27 from the hermetic terminal 20, and the lead wire 28 from the pressure tube 15, which corresponds to the electrode at the other end of the electric heater wire 16, were all insulated and fixed to the hermetic connector 29. It is connected to pin 30. The hermetic connector 29 is connected to the outer cylinder 6 by an O-ring 31.
is fixed airtight.
このような構成によると、もし、圧力管１５の
内部に液体窒素２が入つていても、電気ヒータ線
１６に通電することにより、、この線に接触した
液体はすべて気化し、圧力管１５の中はすべて気
体になる。その結果、圧力管１５の下端には、液
面高さに相当するヘツド圧力と、ガス相４にかか
る圧力とが印加される。一方、半導体式差圧変換
器２２の低圧側管２４は外筒６内及び孔１２を通
じてガス相４に連通し、ガス相４の圧力がかかつ
ている。従つて、半導体式差圧変換器２２から
は、液面ヘツド圧力のみが信号として取り出され
る。差圧変換器のかわりにゲージ圧変換器を用い
ても同じ効果が得られる。真空ケース１４内の真
空が悪いと、熱伝導のため、周囲の液体窒素２に
熱が逃げ、その結果、圧力管１５が冷えて液体窒
素が凝縮することがおこる。その場合でも、電気
ヒータ線１６への供給電力を増やしてやれば、正
しく液面を測ることができる。 According to such a configuration, even if liquid nitrogen 2 is contained inside the pressure pipe 15, by energizing the electric heater wire 16, all the liquid that comes into contact with this wire is vaporized, and the pressure pipe 15 Everything inside becomes gas. As a result, a head pressure corresponding to the liquid level height and a pressure applied to the gas phase 4 are applied to the lower end of the pressure pipe 15. On the other hand, the low pressure side pipe 24 of the semiconductor type differential pressure converter 22 communicates with the gas phase 4 through the inside of the outer cylinder 6 and the hole 12, and the pressure of the gas phase 4 is applied thereto. Therefore, only the liquid level head pressure is taken out as a signal from the semiconductor differential pressure converter 22. The same effect can be obtained by using a gauge pressure transducer instead of a differential pressure transducer. If the vacuum inside the vacuum case 14 is poor, heat will escape to the surrounding liquid nitrogen 2 due to heat conduction, and as a result, the pressure pipe 15 will cool and the liquid nitrogen will condense. Even in that case, the liquid level can be measured correctly by increasing the power supplied to the electric heater wire 16.
第２図は、真空ケース１４のかわりに、合成樹
脂等からなる断熱管３２を用いた例である。ここ
では、液体窒素２の貯槽は省略してある。また、
電気ヒータ線３３は周囲と電気的に絶縁するた
め、往路と復路とからなり、ピン３４でたるみを
防いである。したがつて、ハーメチツクシール３
５も２ピンで、上部は非加熱とし、銅線３６を使
つている。液面計をポート３に固定するのに、こ
こでは、Ｏリング３７とカツプリング３８で結合
している。 FIG. 2 shows an example in which a heat insulating tube 32 made of synthetic resin or the like is used instead of the vacuum case 14. Here, the storage tank for liquid nitrogen 2 is omitted. Also,
In order to electrically insulate the electric heater wire 33 from the surroundings, it consists of an outgoing path and a returning path, and is prevented from sagging by a pin 34. Therefore, hermetic seal 3
5 also has 2 pins, the upper part is not heated, and uses copper wire 36. To fix the liquid level gauge to the port 3, here, it is coupled with an O-ring 37 and a coupling ring 38.
３９はピン・コネクタでケーブル４０で計器に
引き出している。この例では、断熱管３２の断熱
性が、第１図に示した真空ケース１４よりも悪
く、測定時に加えるヒータ電力も増すが、断熱管
３２の長さの調整が比較的自由で低コストであ
る。 39 is a pin connector which is led out to the instrument by a cable 40. In this example, the insulation properties of the insulation tube 32 are worse than the vacuum case 14 shown in FIG. 1, and the heater power applied during measurement increases, but the length of the insulation tube 32 can be adjusted relatively freely and at low cost. be.
第３図は、この液面計の測定方式を示すもので
ある。４１は計器本体で、４２は半導体圧力変換
器、４３は圧力配管中の電気ヒータ、４４はケー
ブルにつなぐコネクター、４５は液体指示メータ
である。ここでは、ａ，ｂが圧力変換器の入力電
流源、ｃ，ｄが圧力変換器からの出力電圧、ｅ，
ｆが、電気ヒータ入力電流端子、ｇ，ｈが計器４
１の交流又は直流電源端子、ｉ，ｊがメータ４５
と同一指示の出力信号端子である。なお、メータ
４５のかわりに、デイジタル表示パネルを用いて
もよい。計器には、主電源スイツチSW1のほか
に、測定スイツチSW2を設け、液面測定時にのみ
短時間通電するようにすれば、冷媒の消費は少な
くてすむ。もちろん、許容できるならば、連続通
電して継続して測定してもよい。 FIG. 3 shows the measurement method of this liquid level gauge. 41 is the instrument body, 42 is a semiconductor pressure transducer, 43 is an electric heater in the pressure piping, 44 is a connector connected to a cable, and 45 is a liquid indicator meter. Here, a, b are the input current sources of the pressure transducer, c, d are the output voltages from the pressure transducer, e,
f is the electric heater input current terminal, g and h are the meter 4
1 AC or DC power supply terminal, i and j are meters 45
This is an output signal terminal with the same instruction as . Note that a digital display panel may be used instead of the meter 45. If the meter is equipped with a measurement switch SW 2 in addition to the main power switch SW 1 , and the power is turned on for a short time only when measuring the liquid level, the consumption of refrigerant can be reduced. Of course, if it is permissible, continuous current may be applied and measurements may be made continuously.
その場合、ヒータ電流を調整するため、可変抵
抗器や切換スイツチを付加してもよい。 In that case, a variable resistor or a changeover switch may be added to adjust the heater current.
本発明によれば、圧力配管の高圧側配管内部を
少なくとも計測時には完全に気体で満たすように
することができるので正しい液面を読みとること
ができるという効果がある。
According to the present invention, the inside of the high-pressure side pipe of the pressure pipe can be completely filled with gas at least during measurement, so there is an effect that the liquid level can be read accurately.
第１図は本発明の一実施例を示す断面図、第２
図は本発明の他の実施例を示す断面図、第３図は
本発明に適用する測定回路のブロツク図である。
２…液体窒素、４…ガス相、１５…圧力管、３
２…断熱管、１６，３３…電気ヒータ線、２２…
半導体式差圧変換器。
FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view showing another embodiment of the present invention, and FIG. 3 is a block diagram of a measuring circuit applied to the present invention. 2...Liquid nitrogen, 4...Gas phase, 15...Pressure pipe, 3
2...Insulated pipe, 16, 33...Electric heater wire, 22...
Semiconductor differential pressure converter.
Claims (1)
を開口し、前記冷媒貯槽の上部気相部に低圧側配
管を開口した差圧測定方式の液面計において、上
記高圧側配管の所定の区間の外側に断熱層を形成
し、上記低圧側配管の圧力導入用外筒を上記高圧
側配管と同軸とし、上記高圧側配管の所定の区間
の内側又は外側に、電気ヒータ線を挿入し又は巻
回し、液面測定時にのみ上記電気ヒータ線に通電
するようにしたことを特徴とする冷媒液面計。1. In a differential pressure measuring liquid level gauge in which a high-pressure side pipe is opened at or near the bottom of the refrigerant storage tank and a low-pressure side pipe is opened at the upper gas phase part of the refrigerant storage tank, a predetermined section of the high-pressure side pipe is opened. A heat insulating layer is formed on the outside, the pressure introducing outer cylinder of the low pressure side piping is made coaxial with the high pressure side piping, and an electric heater wire is inserted or wound inside or outside a predetermined section of the high pressure side piping. A refrigerant level gauge, characterized in that the electric heater wire is energized only when measuring the liquid level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15332787A JPS63317726A (en) | 1987-06-22 | 1987-06-22 | Refrigerant level gauge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15332787A JPS63317726A (en) | 1987-06-22 | 1987-06-22 | Refrigerant level gauge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63317726A JPS63317726A (en) | 1988-12-26 |
| JPH0427491B2 true JPH0427491B2 (en) | 1992-05-12 |
Family
ID=15560066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15332787A Granted JPS63317726A (en) | 1987-06-22 | 1987-06-22 | Refrigerant level gauge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63317726A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5018387A (en) * | 1989-07-27 | 1991-05-28 | Southeastern Universities Research Association | Cryogenic liquid level measuring apparatus |
| JP6020119B2 (en) * | 2012-12-14 | 2016-11-02 | 株式会社Ihi | Liquid level measuring device |
-
1987
- 1987-06-22 JP JP15332787A patent/JPS63317726A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63317726A (en) | 1988-12-26 |
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