JP3400913B2 - Potential measurement device and piping system of power plant - Google Patents
Potential measurement device and piping system of power plantInfo
- Publication number
- JP3400913B2 JP3400913B2 JP17514896A JP17514896A JP3400913B2 JP 3400913 B2 JP3400913 B2 JP 3400913B2 JP 17514896 A JP17514896 A JP 17514896A JP 17514896 A JP17514896 A JP 17514896A JP 3400913 B2 JP3400913 B2 JP 3400913B2
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- Japan
- Prior art keywords
- electrode
- measured
- potential
- reference electrode
- liquid
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
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- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、構造材料の腐食電
位を測定する電位測定装置と、それを有する発電プラン
トの配管系統とに係り、特に原子力プラントや火力プラ
ントの配管系統に設置して構造材料の腐食損傷性を判定
するのに好適なものに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a potential measuring device for measuring a corrosion potential of a structural material and a piping system of a power plant having the potential measuring device, and more particularly, to a structure installed in a piping system of a nuclear power plant or a thermal power plant. It relates to those suitable for determining the corrosion damage of a material.
【０００２】[0002]
【従来の技術】近年、原子力発電や火力発電プラントに
おいて、構造材料の腐食電位を測定して水質を制御しよ
うとする動きが活発化しており、そのため、構造材料の
腐食電位を測定する電位測定装置が開発され、現在、我
が国でも実用化段階にさしかかっている。2. Description of the Related Art In recent years, in nuclear power plants and thermal power plants, the movement to measure the corrosion potential of structural materials to control the water quality has become active, and therefore, a potential measuring device for measuring the corrosion potential of structural materials. Has been developed, and is now in the stage of practical application in Japan.
【０００３】腐食電位について概要を説明すると、例え
ば、室温において酸素等の酸化種を含んだ水溶液中に非
貴金属を浸すと、該金属上で金属の酸化反応（アノード
反応：４Ｍｅ→４Ｍｅ+＋４ｅ）および酸素の還元反応
（カソード反応：０2＋４Ｈ＋＋４ｅ→２Ｈ2Ｏ）が生じ
る。An outline of the corrosion potential will be explained. For example, when a non-noble metal is immersed in an aqueous solution containing an oxidizing species such as oxygen at room temperature, an oxidation reaction of the metal on the metal (anode reaction: 4Me → 4Me + + 4e). And a reduction reaction of oxygen (cathode reaction: 0 2 + 4H ++ 4e → 2H 2 O) occurs.
【０００４】このときの酸化反応および還元反応はお互
いに等しい電子数分だけ釣り合いながら進行する。即
ち、金属の酸化反応で放出された電子は酸素の還元反応
に過不足なく消費される。常温におけ鉄鋼材料の場合、
もし環境中に酸素がなければ、金属が放出した電子を受
容する化学種が存在しないため、金属の溶解や腐食は発
生しない。従って、酸化反応だけが、あるいは還元反応
だけが一方的に進むことはない。At this time, the oxidation reaction and the reduction reaction proceed while balancing each other by the same number of electrons. That is, the electrons released by the metal oxidation reaction are consumed in the oxygen reduction reaction in just proportion. In the case of steel materials at room temperature,
If there is no oxygen in the environment, there is no chemical species that accepts the electrons emitted by the metal, and no metal dissolution or corrosion occurs. Therefore, only the oxidation reaction or only the reduction reaction does not proceed unilaterally.
【０００５】腐食電位はこのように、酸化反応と還元反
応とが釣り合った状態で進んでいるときの金属電極の電
位をいう。The corrosion potential refers to the potential of the metal electrode when the oxidation reaction and the reduction reaction proceed in a balanced manner.
【０００６】この様子を図５の分極曲線を用いて説明す
る。図５において、Ｅｍは金属の平衡電位を示す。平衡
電位とはただ一つの電気化学反応が平衡状態にあるとき
の電位であり、金属の場合、次のＭｎ+＋ｎｅ←→Ｍの
反応における電位である。このＥｍを基点としてこの電
極が分極すると、実線で示したような電流と電位との関
係が得られる。This situation will be described with reference to the polarization curve of FIG. In FIG. 5, Em represents the equilibrium potential of the metal. The equilibrium potential is a potential when only one electrochemical reaction is in an equilibrium state, and in the case of metal, it is a potential in the next reaction of Mn + + ne ← → M. When this electrode is polarized with this Em as the base point, the relationship between current and potential as shown by the solid line is obtained.
【０００７】即ち、電位が貴方向（アノード）へシフト
するとプラスの電流が流れ、逆に電位を卑方向へシフト
するとマイナスの電流が流れる。ここで、プラスの電流
は金属が電子を放出してイオンに変化する酸化反応が進
行し、マイナスの電流は金属イオンが電子を取り込んで
金属に変化する還元反応が進行することを意味する。That is, when the potential shifts in the noble direction (anode), a positive current flows, and conversely, when the potential shifts in the base direction, a negative current flows. Here, the positive current means that the oxidation reaction in which the metal emits an electron and changes into an ion proceeds, and the negative current means that the reduction reaction in which the metal ion takes in an electron and changes into a metal proceeds.
【０００８】これと同様のことを酸素について考えてみ
ると、Ｅｏは酸素の平衡電位を示し、Ｅｏを基点として
電位を卑方向あるいは貴方向にシフトすると、それぞれ
マイナス電流（カソード電流）およびプラス電流（アノ
ード電流）が流れる。酸素のカソード電流は電位が卑に
なっても、電位に依存せず、電流が一定値を示すように
なる。Considering the same thing with oxygen, Eo indicates the equilibrium potential of oxygen, and when the potential is shifted to the base direction or the noble direction with Eo as the base point, a negative current (cathode current) and a positive current, respectively. (Anode current) flows. The cathode current of oxygen does not depend on the potential even if the potential becomes base, and the current shows a constant value.
【０００９】酸素の還元反応が進行すると、電極表面が
酸素が消費されることになり、電極表面の酸素濃度が低
下する。これを補うため、バルク溶液から酸素が電極表
面に濃度勾配に基づいて拡散するが、この拡散が還元反
応の進行を律速するため、カソード電流は電位によらず
一定になる。腐食電位は図中、Ｅｃｏｒｒ１，２にて示
したような金属のアノード電流と酸素のカソード電流の
絶対値が一致するところの電位である。When the oxygen reduction reaction proceeds, oxygen is consumed on the electrode surface, and the oxygen concentration on the electrode surface decreases. In order to compensate for this, oxygen diffuses from the bulk solution to the electrode surface based on the concentration gradient, but this diffusion controls the progress of the reduction reaction, so that the cathode current becomes constant regardless of the potential. The corrosion potential is a potential at which the absolute values of the anode current of metal and the cathode current of oxygen coincide with each other as indicated by Ecorr 1 and 2 in the figure.
【００１０】腐食電位の実際の測定は、電位の基準とな
る参照電極と被測定物である金属電極とを目的とする環
境中に浸し、前記参照電極に対して金属電極の電位がい
くらになるかを、端子間の電圧を測定する装置を用いて
行う。但し、電圧測定装置の入力インピーダンスが被測
定系のインピーダンスより十分大きく、かつ、この電圧
測定装置は、参照電極，金属電極に極力電流が流れない
ものであることが要求される。その理由は、電圧測定に
際し、参照電極，金属電極に電流が流れると、それぞれ
の電極の電位が変わることがあるためである。In actual measurement of the corrosion potential, the reference electrode serving as the reference of the potential and the metal electrode as the object to be measured are immersed in the intended environment, and the potential of the metal electrode becomes relative to the reference electrode. This is done using a device that measures the voltage across the terminals. However, it is required that the input impedance of the voltage measuring device is sufficiently larger than the impedance of the system under measurement, and that this voltage measuring device is such that no current flows through the reference electrode and the metal electrode as much as possible. The reason is that the potential of each electrode may change when a current flows through the reference electrode and the metal electrode during voltage measurement.
【００１１】腐食電位は通常、金属電極の組成，金属電
極周囲の環境により変化する。その典型的な例として、
常温の海水中におけるＳＵＳ３１６ステンレス鋼と炭素
鋼の腐食電位を比較した場合、ＳＵＳ３１６ステンレス
鋼の腐食電位は炭素鋼のそれより数１００ｍＶ高い。一
方、同じＳＵＳ３１６ステンレス鋼であっても、大気飽
和ほどの溶存酸素が存在するときと、酸素がほとんど存
在しないとき（約０ｐｐｂ以下）とを比較すると、溶存
酸素が存在するときの方が存在しないときより、５００
ｍＶほど高くなる。このように腐食電位は金属の組成や
環境により変化する。The corrosion potential usually changes depending on the composition of the metal electrode and the environment around the metal electrode. As a typical example,
When comparing the corrosion potentials of SUS316 stainless steel and carbon steel in seawater at room temperature, the corrosion potential of SUS316 stainless steel is several hundred mV higher than that of carbon steel. On the other hand, even when the same SUS316 stainless steel is used, when comparing the presence of dissolved oxygen to the extent of atmospheric saturation with the presence of almost no oxygen (approximately 0 ppb or less), there is no presence of dissolved oxygen. From time to time, 500
It becomes as high as mV. Thus, the corrosion potential changes depending on the metal composition and environment.
【００１２】このほか、腐食電位は流速にも影響され
る。流速が速いと腐食電位は増加する傾向を示す。これ
は、金属表面に到達できる酸素量が増加するからであ
る。例えば図５に示すように、流速が速くなると、バル
ク溶液からの酸素の拡散が速くなる。換言すると、金属
が放出した電子を受容する物質が多く供給される結果、
腐食電位Ｅｏｒｒは流速の増加とともに貴方向にシフト
することとなる。Besides, the corrosion potential is also affected by the flow velocity. The corrosion potential tends to increase as the flow velocity increases. This is because the amount of oxygen that can reach the metal surface increases. For example, as shown in FIG. 5, the faster the flow rate, the faster the diffusion of oxygen from the bulk solution. In other words, as a result of supplying a lot of substances that accept the electrons emitted by the metal,
The corrosion potential Eorr shifts in the noble direction as the flow velocity increases.
【００１３】もし、電位の測定対象部位の流速が部分部
分で異なると、腐食電位は測定対象部と参照電極間の電
位分布の強度に応じた平均的な値となる。従って、腐食
電位に及ぼす流速の影響を調べるときは、流速を明確に
知ることができるような条件下で腐食電位を測定する必
要がある。If the flow velocity of the potential measurement target portion is different in the partial portion, the corrosion potential becomes an average value according to the strength of the potential distribution between the measurement target portion and the reference electrode. Therefore, when investigating the influence of the flow velocity on the corrosion potential, it is necessary to measure the corrosion potential under the condition that the flow velocity can be clearly known.
【００１４】さらに、腐食電位は材料の腐食挙動と密に
関係する。例えば、発電プラントの蒸気タービンの動翼
等に使用されるマルテンサイト系ステンレス鋼は、腐食
電位が低下すると、腐食疲労亀裂進展速度が低下するこ
とが知られている。オーステナイト系ステンレス鋼も腐
食電位が低下するに従って応力腐食割れ感受性が低下す
る。このように、腐食電位をモニタすることによって材
料の腐食環境を把握することが可能となる。Furthermore, the corrosion potential is closely related to the corrosion behavior of the material. For example, it is known that the martensitic stainless steel used for the blades of a steam turbine of a power plant has a reduced corrosion fatigue crack growth rate when the corrosion potential decreases. Austenitic stainless steels also have lower susceptibility to stress corrosion cracking as the corrosion potential decreases. In this way, by monitoring the corrosion potential, it is possible to grasp the corrosive environment of the material.
【００１５】上述の如く、腐食電位を測定することは、
材料がおかれた腐食環境を推定する上で、有用な方法で
あり、先に述べたように、これには腐食電位を左右する
流速を予め正確に把握することが重要である。As mentioned above, measuring the corrosion potential is
This is a useful method for estimating the corrosive environment in which the material is placed, and as described above, it is important to accurately grasp the flow velocity that influences the corrosion potential in advance.
【００１６】ところで、従来の腐食電位測定装置として
は、例えばＥＰＲＩのレポート（ＮＰ−３５２１ Ｐｒ
ｏｊｅｃｔ ７０６−１ Ｆｉｎａｌ Ｒｅｐｏｒｔ
Ｍａｙ １９８４）において、円筒状のオートクレーブ
に電位の基準となる参照電極、及び被測定対象の金属電
極が任意に装荷され、参照電極と金属電極間の電位を測
定することが記載されている。あるいは、単に参照電極
のみを装荷し、参照電極とオートクレーブ間の電位を電
圧計やエレクトロメータを用いて測定することが記載さ
れている。A conventional corrosion potential measuring device is, for example, an EPRI report (NP-3521 Pr).
object 706-1 Final Report
May 1984) describes that a cylindrical autoclave is optionally loaded with a reference electrode serving as a potential reference and a metal electrode to be measured, and the potential between the reference electrode and the metal electrode is measured. Alternatively, it is described that only the reference electrode is loaded and the potential between the reference electrode and the autoclave is measured using a voltmeter or an electrometer.
【００１７】また、他の従来技術として、ＥＰＲＩのレ
ポート（ＮＰ−６７３２ Ｍａｒｃｈ １９９０）に
は、腐食電位に及ぼす流速の影響を調べる場合、金属チ
ューブ内に参照電極を挿入し、金属チューブと参照電極
との間の電位を測定することが記載されている。As another conventional technique, in the report of EPRI (NP-6732 March 1990), when investigating the influence of flow velocity on the corrosion potential, a reference electrode is inserted in a metal tube, and the metal tube and the reference electrode are inserted. It is described to measure the potential between and.
【００１８】[0018]
【発明が解決しようとする課題】ところで、腐食電位の
測定に際しては、上述した如く、金属の組成，温度，環
境中の酸化還元種の種類や濃度のみならず、金属電極表
面の流速の影響を大きく受けるので、流速を明確に把握
した状態で測定することが肝要である。By the way, in measuring the corrosion potential, as described above, the influence of the flow velocity on the surface of the metal electrode as well as the composition and temperature of the metal and the kind and concentration of the redox species in the environment are measured. Since it is greatly affected, it is important to measure with the flow velocity clearly understood.
【００１９】しかしながら、上記に示す第一の従来技術
のものは参照電極と金属電極（あるいはオートクレー
ブ）間の電位を測定すると云う原理的な記載内容であ
り、ある程度おおまかな流速を知ることができるが、ミ
クロ的な目で見ると、金属電極表面の流速が部分部分に
よって異なることがあるので、測定される腐食電位は平
均的な値となり、そのため、正確な腐食電位を得ること
が難しい問題がある。However, the above-mentioned first prior art is the description of the principle that the potential between the reference electrode and the metal electrode (or the autoclave) is measured, and the flow velocity can be roughly known to some extent. From a microscopic point of view, the flow velocity on the surface of the metal electrode may differ depending on the part, so the measured corrosion potential will be an average value, so there is a problem that it is difficult to obtain an accurate corrosion potential. .
【００２０】また第二の従来技術のものは、腐食電位に
及ぼす流速の影響を調べるため、金属チューブを用いる
ことが記載されているものの、金属チューブ内に装荷す
る参照電極の構造が明示されておらず、即ち、参照電極
の電位検出口に相当する液絡部から金属チューブまでの
距離，位置関係が不明であるため、電位測定対象部位の
正確な流速を求めることができず、その結果、腐食電位
を測定しても、腐食評価の信頼性に乏しい問題がある。In the second prior art, it is described that a metal tube is used in order to investigate the influence of the flow velocity on the corrosion potential. However, the structure of the reference electrode loaded in the metal tube is clarified. No, that is, since the distance from the liquid junction corresponding to the potential detection port of the reference electrode to the metal tube and the positional relationship are unknown, it is not possible to obtain an accurate flow velocity at the potential measurement target site, and as a result, Even if the corrosion potential is measured, there is a problem that the reliability of the corrosion evaluation is poor.
【００２１】本発明の目的は、上記従来技術の問題点に
鑑み、金属表面の流速を正確に把握でき、以て正確な腐
食電位を測定し得る電位測定装置を提供することにあ
り、また、他の目的は、所望の種々の流速環境を容易に
形成でき、その種々の流速環境下での電位を測定し得る
電位測定装置を提供することにあり、さらに他の目的
は、流速が時間によって変化する場合などでも、実現し
得る電位測定装置を提供することにある。In view of the above problems of the prior art, an object of the present invention is to provide an electric potential measuring device capable of accurately grasping the flow velocity on the metal surface and thereby measuring an accurate corrosion potential. Another object is to provide an electric potential measuring device capable of easily forming desired various flow velocity environments and capable of measuring an electric potential under the various flow velocity environments. An object of the present invention is to provide an electric potential measuring device that can be realized even when it changes.
【００２２】さらに、本発明の目的は、発電プラントの
給水系に利用し、該給水系の腐食電位を正確に得ること
により、配管系統の腐食評価を正確に行い得る発電プラ
ントの配管系統を提供することにある。Further, the object of the present invention is to provide a piping system of a power plant, which can be used for a water supply system of a power plant, and by accurately obtaining the corrosion potential of the water supply system, the corrosion of the piping system can be accurately evaluated. To do.
【００２３】[0023]
【課題を解決するための手段】本発明の電位測定装置に
おいては、内径が軸方向に沿い同一寸法をなす円筒状の
被測定電極と、該被測定電極の内部に設置され、外径が
軸方向に沿い同一寸法をなし且つ電位感知口としての液
絡部を設けた円柱状の参照電極と、参照電極の液絡部の
電圧に基づき被測定電極の電位を測定する電位測定部と
を有し、前記参照電極が、該参照電極の外周と前記被測
定電極の内周との間に形成される流路が軸方向における
何れの位置でも同一の間隙を有するように、当該参照電
極の軸線が被測定電極の軸線と平行に配置されており、
前記液絡部が、前記参照電極の外周部の軸線上であり且
つその軸線の略中央部に配置されていることを特徴とす
るものである。In the potential measuring device of the present invention, a cylindrical electrode to be measured whose inner diameter has the same dimension along the axial direction, and an outer diameter which is installed inside the electrode to be measured. Yes a cylindrical reference electrode having a liquid junction as and potential sensing port without the same dimension along the direction, based on the voltage of the reference electrode liquid junction and a potential measuring unit for measuring the potential of the measuring electrode However, the reference electrode and the outer circumference of the reference electrode are
The flow path formed between the inner circumference of the constant electrode and
The reference voltage should be the same so that the same gap is obtained at all positions.
The axis of the pole is arranged parallel to the axis of the electrode to be measured,
The liquid junction is on the axis of the outer periphery of the reference electrode and
It is characterized in that it is arranged substantially in the center of its axis .
【００２４】本発明の発電プラントにおいては、給水を
高圧加熱する給水加熱手段と、該給水加熱手段からの高
圧水をさらに加熱し、蒸気を生成する手段とを有する発
電プラントにおいて、給水加熱手段と蒸気を生成する手
段との間の配管の途中位置に接続された分岐管と、該分
岐管の途中位置に接続され、内径が軸方向に沿い同一寸
法をなす円筒状の被測定電極と、該被測定電極の内部に
設置され、外径が軸方向に沿い同一寸法をなすと共に、
軸線が被測定電極の軸線と平行に配置され、かつ電位感
知口としての液絡部を設けた円柱状の参照電極と、参照
電極の液絡部の電圧に基づき被測定電極の電位を測定す
る電位測定部と、該電位測定部の出力に基づき給水加熱
手段の上流側に水質改善用の薬品を注入する薬品注入部
とを有する電位測定装置を備えたことを特徴とするもの
である。[0024] In the power plant of the present invention includes a feedwater heater means for high-pressure heated water, further heating the high-pressure water from the water supply the heating means, the power plant having means for generating steam, a water supply heating means Hands that generate steam
A branch pipe connected to the middle position of the pipe between the step and the pipe, a cylindrical electrode under measurement connected to the middle position of the branch pipe and having the same inner diameter along the axial direction, and the electrode under measurement. Installed inside, the outer diameter is the same along the axial direction,
The axis of the reference electrode is arranged parallel to the axis of the electrode to be measured, and a cylindrical reference electrode provided with a liquid junction as a potential sensing port, and the potential of the electrode to be measured is measured based on the voltage of the liquid junction of the reference electrode. It is characterized by comprising a potential measuring device having a potential measuring part and a chemical injection part for injecting a chemical for water quality improvement on the upstream side of the feed water heating means based on the output of the potential measuring part.
【００２５】[0025]
【発明の実施の形態】以下、本発明の実施例を図１乃至
図１０により説明する。図１は本発明による電位測定装
置の概念を示している。本発明の電位測定装置は、図１
（ａ）及び（ｂ）に示すように、被測定電極１の内部に
電位感知口としての液絡部３を有する参照電極２が設置
されている。被測定電極１は、内部に液体を左側から右
側方向に流通させるように円筒状をなしており、その内
径が軸方向に沿い同一寸法に形成されると共に、外径も
軸方向に沿い同一寸法に形成されている。参照電極２は
被測定電極１の内径と同様、外径が軸方向に沿い同一寸
法となるよう円柱状に形成されている。この参照電極２
は、ある特定の電気化学平衡反応を形成するような電極
で構成され、被測定電極１の内部において該被測定電極
１の軸線と参照電極２の軸線とが平行となるように配置
されている。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows the concept of a potential measuring device according to the present invention. The potential measuring device of the present invention is shown in FIG.
As shown in (a) and (b), a reference electrode 2 having a liquid junction 3 as a potential sensing port is installed inside the electrode 1 to be measured. The electrode 1 to be measured has a cylindrical shape so that the liquid flows from the left side to the right side inside, and the inner diameter thereof is formed to have the same dimension along the axial direction, and the outer diameter also has the same dimension along the axial direction. Is formed in. Like the inner diameter of the measured electrode 1, the reference electrode 2 is formed in a cylindrical shape so that the outer diameter has the same dimension along the axial direction. This reference electrode 2
Is composed of electrodes that form a specific electrochemical equilibrium reaction, and is arranged inside the measured electrode 1 such that the axis of the measured electrode 1 and the axis of the reference electrode 2 are parallel to each other. .
【００２６】本発明は、上記の如く、円筒状の被測定電
極１の管中に円柱状の参照電極２が配置されているの
で、該参照電極２の液絡部３と、被測定電極１の内周に
おいて前記液絡部３と対向する部分との間では同一の間
隙（流路）をもつこととなり、そのため、被測定電極１
において参照電極２の液絡部３が配置されている部分で
の流速が均一となる。According to the present invention, as described above, since the cylindrical reference electrode 2 is arranged in the tube of the cylindrical electrode 1 to be measured, the liquid junction 3 of the reference electrode 2 and the electrode 1 to be measured. There is the same gap (flow path) between the portion facing the liquid junction 3 on the inner periphery of the electrode, and therefore the measured electrode 1
In, the flow velocity becomes uniform in the portion of the reference electrode 2 where the liquid junction 3 is arranged.
【００２７】即ち、被測定電極１に液体を左側から右側
方向に流すと、参照電極２の先端から後端の間で流路が
狭まるので、流速が増加する。そして、流速が増加した
液体は、参照電極２を通過すると、流速は元に戻る。That is, when the liquid is flown to the electrode 1 to be measured from the left side to the right side, the flow path is narrowed between the front end and the rear end of the reference electrode 2, so that the flow velocity is increased. Then, when the liquid having the increased flow velocity passes through the reference electrode 2, the flow velocity returns to the original.
【００２８】ここで、図１（ｂ）に示すように被測定電
極１において参照電極２までの領域をＡ、参照電極２に
対応する領域をＢ、参照電極２以降の領域をＣとする
と、同図（ｃ）に示すように、領域Ａと領域Ｃとにおけ
る前記被測定電極１内の液体流速は等しいが、領域Ｂで
は参照電極２が占める体積分だけ流速が速くなる。この
領域Ｂにおける被測定電極１内の流速は、単位時間に流
れる液体の量と被測定電極１の内径と参照電極２の外径
との関係から求めることができる。Here, as shown in FIG. 1B, in the measured electrode 1, the area up to the reference electrode 2 is A, the area corresponding to the reference electrode 2 is B, and the area after the reference electrode 2 is C. As shown in FIG. 6C, the liquid velocities in the electrode 1 to be measured are equal in the region A and the region C, but in region B, the flow velocity is increased by the volume of the reference electrode 2 occupied. The flow velocity in the measured electrode 1 in this region B can be obtained from the relationship between the amount of liquid flowing per unit time, the inner diameter of the measured electrode 1 and the outer diameter of the reference electrode 2.
【００２９】例えば、被測定電極１の内径をＤ１
（ｍ）、参照電極２の外径をＤ２、単位時間当たりの流
量をＶ（ｍ3／ｓ）とすると、参照電極２が設置されて
いない場所の流速は４Ｖ／πＤ１2となる。一方、参照
電極２が設置されている場所の流速は以下の式となる。For example, if the inner diameter of the measured electrode 1 is D1
(M), assuming that the outer diameter of the reference electrode 2 is D2 and the flow rate per unit time is V (m 3 / s), the flow velocity at the place where the reference electrode 2 is not installed is 4V / πD1 2 . On the other hand, the flow velocity at the place where the reference electrode 2 is installed is given by the following formula.
【００３０】[0030]
【数１】４Ｖ／π（Ｄ１2−Ｄ２2）
従って、液体が流れる流量がわかれば、前記被測定電極
１の流速を知ることができる。## EQU1 ## 4V / π (D1 2 -D2 2 ) Therefore, if the flow rate of the liquid is known, the flow velocity of the electrode 1 to be measured can be known.
【００３１】電位の測定に際しては、参照電極２の液絡
口３を通して行われる。従って、前記液絡口３が領域Ａ
／Ｂや領域Ｂ／Ｃの境界部あるいは参照電極２の先端に
ある構造の場合、測定される電位は領域Ａや領域Ｂある
いは領域Ｃの電位が混じった状態で与えられる。The potential is measured through the liquid junction 3 of the reference electrode 2. Therefore, the liquid junction 3 has an area A
In the case of a structure at the boundary between / B and the region B / C or at the tip of the reference electrode 2, the measured potential is given in a state in which the potentials of the regions A, B and C are mixed.
【００３２】本発明では、参照電極２において領域Ａ／
Ｂや領域Ｂ／Ｃの境界部から離れた領域に液絡口３が配
置されるので、領域Ｂの電位のみを測定することがで
き、しかも上述の如く、円筒状の被測定電極１の管中に
円柱状の参照電極２が配置され、該参照電極２の液絡部
３と、被測定電極１の内周における前記液絡部３と対向
する部分との間の流路が軸方向において何れの位置でも
同一の間隙をもっているので、正確に測定することがで
きる。In the present invention, the area A /
Since the liquid junction 3 is arranged in a region away from the boundary between B and the region B / C, only the potential of the region B can be measured, and as described above, the tube of the cylindrical electrode 1 to be measured is measured. A cylindrical reference electrode 2 is arranged therein, and a flow path between the liquid junction 3 of the reference electrode 2 and a portion of the inner circumference of the electrode 1 to be measured facing the liquid junction 3 is axially arranged. Since the gap is the same at any position, accurate measurement can be performed.
【００３３】本発明は、以上の概念に基づいたものであ
るので、次に本発明の一実施例について図２および図３
を用いて詳細に述べる。参照電極２は図２に示すよう
に、被測定電極１の内部に固定された４個の固定板４に
取付けられ、その軸線が被測定電極１の軸線と一致して
配置されている。固定板４は、被測定電極１の内周にお
いて例えば９０度の等間隔をもって固定されている。被
測定電極１は図１に示したものと同様であるので、ここ
では説明を省略する。Since the present invention is based on the above concept, an embodiment of the present invention will be described with reference to FIGS.
Will be described in detail using. As shown in FIG. 2, the reference electrode 2 is attached to four fixing plates 4 fixed inside the electrode 1 to be measured, and its axis is aligned with the axis of the electrode 1 to be measured. The fixed plate 4 is fixed on the inner circumference of the electrode 1 to be measured at equal intervals of 90 degrees, for example. The electrode 1 to be measured is the same as that shown in FIG. 1, and therefore its explanation is omitted here.
【００３４】前記参照電極２は図３に示すように、電気
的導通を防ぐため絶縁性の四フッ化ポリエチレン（ＰＴ
ＦＥ）で形成された筒状の本体８と、本体８の前後部に
夫々設けられた前蓋９及び後蓋１０と、本体８内に封入
され、例えば０．１Ｍの濃度からなる塩化カリウム溶液
７と、該本体８の内部に塩化銀１１を融着して配線さ
れ、後蓋１０を貫通して外部に引き出される銀線からな
る電位信号線６と、本体８の外周部に設けられた液絡口
３とを有している。As shown in FIG. 3, the reference electrode 2 is made of insulating tetrafluoropolyethylene (PT) in order to prevent electrical conduction.
FE) cylindrical main body 8, a front lid 9 and a rear lid 10 provided at the front and rear portions of the main body 8, and a potassium chloride solution enclosed in the main body 8 and having a concentration of, for example, 0.1M. 7 and a potential signal line 6 made of a silver wire that is fused and wired with silver chloride 11 inside the main body 8 and that extends through the rear lid 10 to the outside, and is provided on the outer peripheral portion of the main body 8. It has a liquid junction 3.
【００３５】この液絡部３は、電位測定の際、微少な電
流が流れるようにすると共に、被測定電極１を流れる液
体と本体８内の塩化カリウム溶液７とが極力混じり合わ
ないようにするため、微小な大きさのジルコニア製によ
り形成されている。この液絡部３は、本体８の外周部の
軸線上に、即ち、参照電極外周部の軸線上であってしか
も軸線の中央部の位置に配置されている。The liquid junction 3 allows a minute current to flow during potential measurement, and prevents the liquid flowing through the electrode 1 to be measured from mixing with the potassium chloride solution 7 in the main body 8 as much as possible. Therefore, it is formed of zirconia having a minute size. The liquid junction 3 is arranged on the axis of the outer periphery of the main body 8, that is, on the axis of the outer periphery of the reference electrode and at the center of the axis.
【００３６】再び図２に戻り、電位測定装置は、上記被
測定電極１と参照電極２との他、電位測定部５を有して
いる。この電位測定部５は、被測定電極１と参照電極２
間の電圧を測定するためのものであり、一端には電位信
号線１９を介し被測定電極１の外周部に設けられた端子
１３と接続される一方、他端には参照電極２から引き出
された電位信号線６と接続されている。この場合、例え
ば被測定電極１の電位信号線１９が＋側（Ｈｉｇｈ側）
に、かつ電位信号線６が−側（Ｌｏｗ側）に夫々接続さ
れる。従って、参照電極２の電位信号線６は、被測定電
極１を貫通して接続されるので、四フッ化ポリエチレン
製の絶縁チューブ１２により、被測定電極１と直接接触
しないように被覆されている。Returning to FIG. 2 again, the potential measuring device has a potential measuring section 5 in addition to the measured electrode 1 and the reference electrode 2. The potential measuring unit 5 includes a measured electrode 1 and a reference electrode 2
It is for measuring the voltage between them, and is connected to a terminal 13 provided on the outer peripheral portion of the electrode 1 to be measured through a potential signal line 19 at one end, and is drawn from the reference electrode 2 at the other end. Connected to the potential signal line 6. In this case, for example, the potential signal line 19 of the measured electrode 1 is on the + side (High side)
And the potential signal line 6 is connected to the − side (Low side), respectively. Therefore, since the potential signal line 6 of the reference electrode 2 is connected through the measured electrode 1, it is covered with the insulating tube 12 made of polyethylene tetrafluoride so as not to come into direct contact with the measured electrode 1. .
【００３７】従って、この電位測定装置は、内径が軸方
向に同一寸法をなす円筒状の被測定電極１と、その被測
定電極１内に該被測定電極の軸線と一致して配置され、
かつ軸方向に同径をなす円柱状の参照電極２と、参照電
極２及び被測定電極１間の電圧を電位測定部５とを有し
て構成されている。Therefore, this potential measuring device is provided with a cylindrical electrode 1 to be measured whose inner diameter has the same dimension in the axial direction, and in the electrode 1 to be measured, aligned with the axis of the electrode to be measured,
In addition, it has a cylindrical reference electrode 2 having the same diameter in the axial direction, and a potential measuring unit 5 for measuring the voltage between the reference electrode 2 and the electrode 1 to be measured.
【００３８】図２，図３に示す実施例の電位測定装置
は、円筒状の被測定電極１の管中にその軸線と一致する
ように円柱状の参照電極２が配置されているので、参照
電極２の外周と被測定電極１の内周との間が軸方向にお
いて何れの位置でも同一の間隙をもつこととなる。その
ため、被測定電極１において参照電極２が配置されてい
る部分での流速を確実に均一となる。In the potential measuring device of the embodiment shown in FIGS. 2 and 3, the cylindrical reference electrode 2 is arranged in the tube of the cylindrical electrode 1 to be measured so as to coincide with the axis thereof. The outer circumference of the electrode 2 and the inner circumference of the measured electrode 1 have the same gap at any position in the axial direction. Therefore, the flow velocity in the portion of the measured electrode 1 where the reference electrode 2 is arranged can be surely made uniform.
【００３９】因みに、被測定電極１として１２Ｃｒマル
テンサイト系ステンレス鋼で形成し、これに流量１．０
ｄｍ3／ｓ，３０℃の純水を流通させたときの電位の経
時変化について説明する。なお、被測定電位１を流通す
る純水には１０ｐｐｂの酸素が溶け込んでいる。被測定
電位１としては、長さが１ｍ，内径が５２ｍｍの大きさ
であり、参照電極２としては長さが１００ｍｍ，外形が
１０ｍｍである。参照電極２における液絡部３の位置
は、参照電極２の上流側先端から５０ｍｍの位置にあ
る。いま、被測定電極１内に１ｄｍ3／ｈの流量を流
し、そのときの参照電極２と被測定電極１の間を流れる
液体の線流速は、数１式から０．４９ｍ／ｓとなる。図
４に示す高流速Ｘは、上記条件下で測定した被測定電極
１の電位を表しており、測定開始直後を除き、電位が時
間に拘わらずほぼ一定に推移していることがわかる。Incidentally, the electrode 1 to be measured was made of 12Cr martensitic stainless steel, and the flow rate was 1.0.
The change with time in the potential when pure water of dm 3 / s and 30 ° C. is passed will be described. In addition, 10 ppb of oxygen is dissolved in the pure water flowing through the measured potential 1. The potential to be measured 1 has a length of 1 m and an inner diameter of 52 mm, and the reference electrode 2 has a length of 100 mm and an outer diameter of 10 mm. The position of the liquid junction 3 in the reference electrode 2 is 50 mm from the upstream end of the reference electrode 2. Now, a linear flow velocity of the liquid flowing between the reference electrode 2 and the measured electrode 1 at a flow rate of 1 dm 3 / h flowing into the measured electrode 1 is 0.49 m / s from the equation (1). The high flow velocity X shown in FIG. 4 represents the potential of the measured electrode 1 measured under the above conditions, and it can be seen that the potential remains substantially constant regardless of time except immediately after the start of measurement.
【００４０】次に、被測定電極１内に０．０１ｄｍ3／
ｓで測定した電位の経時変化を図４に低流速Ｙで表し、
この低流速Ｙにおいても電位が時間に拘わらずほぼ一定
に推移している。このときの参照電極２と被測定電極１
の間を流れる液体の線流速は数１式から０．００４９ｍ
／ｓである。図４より、流量１．０ｄｍ3／ｓの高流速
Ｘと、流量０．０１ｄｍ3／ｓの低流速Ｙとの電位を観
察すると、高流速Ｘの電位より低流速の電位が約０．１
Ｖほど高い値を示す。Next, 0.01 dm 3 /
The change over time of the potential measured with s is represented by the low flow velocity Y in FIG.
Even at this low flow velocity Y, the potential remains almost constant regardless of time. Reference electrode 2 and measured electrode 1 at this time
The linear flow velocity of the liquid flowing between the two is 0.0049m from the formula 1
/ S. From FIG. 4, a high flow rate X of the flow rate 1.0 dm 3 / s, when observing the potential of the low velocity Y of the flow 0.01dm 3 / s, the potential of the low flow rates than the potential of the high flow rate X of about 0.1
The higher the value V, the higher the value.
【００４１】比較例として、液絡部３を、参照電極２の
本体８の上流側にある前蓋９に設置し、上記と同様に流
量１．０ｄｍ3／ｓの試験をすると、その電位は、図４
に破線Ｚにて示すよう、平均的に数十ｍＶほど低くな
り、また液絡部３が前蓋９に設置したとき、液体が直接
衝突する場所でもあることから、上下に多少変動してい
ることが理解できよう。As a comparative example, when the liquid junction 3 is installed on the front lid 9 on the upstream side of the main body 8 of the reference electrode 2 and a flow rate of 1.0 dm 3 / s is tested in the same manner as above, the potential is , Fig. 4
As indicated by a broken line Z, the average voltage is lowered by several tens of mV, and when the liquid junction 3 is installed on the front lid 9, the liquid directly collides with the liquid junction 3 and thus fluctuates slightly up and down. You can understand that.
【００４２】従って、液体の流速の変化する場所や、液
体の流れの妨げになるような場所に液絡部３を設ける
と、測定される電位に差が生じるが、被測定電極１に対
し図２にて前述した如く参照電極２及び液絡部３を配置
すれば、液体の流速を安定化かつ均一化させることがで
き、液体の流速を把握できる。その結果、流速の把握し
た状態の中で電位測定を行うので、それだけ電位測定を
正確に行うことができる。Therefore, if the liquid junction 3 is provided at a place where the flow velocity of the liquid changes or a place where the flow of the liquid is obstructed, a difference in measured potential occurs, but the measured potential is different from the measured electrode 1. By disposing the reference electrode 2 and the liquid junction 3 as described in 2 above, the flow velocity of the liquid can be stabilized and made uniform, and the flow velocity of the liquid can be grasped. As a result, since the electric potential is measured while the flow velocity is known, the electric potential can be accurately measured accordingly.
【００４３】図６は本発明の第二の実施例を示す。この
場合は、被測定電極１として、内径が軸方向に階段状に
変化する形状に形成されている。FIG. 6 shows a second embodiment of the present invention. In this case, the measured electrode 1 is formed in a shape whose inner diameter changes stepwise in the axial direction.
【００４４】即ち、階段状の被測定電極１は、全体とし
てＬ字形に形成されており、その内部においては元管１
６に接続され、参照電極２の外径より若干大きい内径を
有する第一の部分１Ａと、第一の部分１Ａにテーパ状の
拡径部１ａを介し連続すると共に、第一の部分１Ａより
若干内径が大きく形成された第二の部分１Ｂと、該第二
の部分１Ｂにテーパ状の拡径部１ｂを介し連続すると共
に、第二の部分１Ｂより若干内径が大きく形成された第
三の部分１Ｃと、該第三の部分１Ｃにテーパ状の拡径部
１ｃを介し連続すると共に、第三の拡径部１Ｃより若干
内径が大きく形成された第四の部分１Ｄと、該第四の部
分１Ｄにテーパ状の縮径部１ｄを介し連続すると共に、
第四の部分１Ｄに対し直角方向（下方）に屈曲する第五
の部分１Ｅとを有している。これら各第一の部分１Ａ〜
第四の部分１Ｄは共に同軸上に配置されている。That is, the step-like electrode 1 to be measured is formed in an L-shape as a whole, and the inside of the source tube 1 is inside.
6 is connected to the first portion 1A having an inner diameter slightly larger than the outer diameter of the reference electrode 2 and is continuous to the first portion 1A via the tapered expanded portion 1a, and is slightly larger than the first portion 1A. A second portion 1B having a large inner diameter and a third portion which is continuous with the second portion 1B via a tapered enlarged diameter portion 1b and has a slightly larger inner diameter than the second portion 1B. 1C, a fourth portion 1D which is continuous with the third portion 1C via a tapered enlarged portion 1c, and which has an inner diameter slightly larger than that of the third enlarged portion 1C, and the fourth portion. While continuing to 1D through the tapered diameter reducing portion 1d,
The fourth portion 1D has a fifth portion 1E which is bent at a right angle (downward) with respect to the fourth portion 1D. Each of these first parts 1A-
The fourth portions 1D are arranged coaxially with each other.
【００４５】一方、参照電極２の一端には電位信号線６
を挿通している駆動棒１５が取付けられている。駆動棒
１５は、その先端部が被測定電極１を挿通すると共に、
被測定電極１の第一の部分１Ａ〜第四の部分１Ｄの軸方
向に沿って配置され、被測定電極１における第四の部分
１Ｄ側の外壁に設けられた駆動部１４により、第一の部
分１Ａ〜第四の部分１Ｄ内の軸線上を移動するように構
成されている。駆動部１４は、例えば２個のローラ１４
ａ，１４ｂを有し、図示しない操作部の操作によってロ
ーラ１４ａ，１４ｂが回転したとき、駆動棒１５を移動
させる。On the other hand, the potential signal line 6 is provided at one end of the reference electrode 2.
A drive rod 15 which is inserted through is attached. The drive rod 15 has its tip inserted through the electrode 1 to be measured, and
By the drive unit 14 that is arranged along the axial direction of the first portion 1A to the fourth portion 1D of the measured electrode 1, and is provided on the outer wall of the measured electrode 1 on the fourth portion 1D side, It is configured to move on an axis in the portion 1A to the fourth portion 1D. The drive unit 14 includes, for example, two rollers 14
When the rollers 14a and 14b have a and 14b and are rotated by an operation of an operation unit (not shown), the drive rod 15 is moved.
【００４６】従って、駆動部１４の駆動によって駆動棒
１５が移動すると、参照電極２が第一の部分１Ａ〜第４
の部分１Ｄの所望の位置に移動する。なお、この場合の
参照電極２の内部構成については前記第一の実施例と同
様であるので、ここではその説明を省略する。Therefore, when the drive rod 15 is moved by the drive of the drive unit 14, the reference electrode 2 causes the reference electrode 2 to move from the first portion 1A to the fourth portion.
Move to the desired position of the part 1D of. Since the internal structure of the reference electrode 2 in this case is the same as that of the first embodiment, its explanation is omitted here.
【００４７】他方、階段状の被測定電極１の端子１３か
ら引き出された電位信号線１９と、駆動棒１５から引き
出された電位信号線６とが電位測定部５に接続され、該
電位測定部５により被測定電極１と参照電極２間の電圧
を測定する。On the other hand, the potential signal line 19 drawn from the terminal 13 of the stepped electrode 1 to be measured and the potential signal line 6 drawn from the driving rod 15 are connected to the potential measuring section 5, and the potential measuring section 5 is connected. 5, the voltage between the measured electrode 1 and the reference electrode 2 is measured.
【００４８】この実施例によれば、被測定電極１内に液
体を流通させているとき、該被測定電極１の各部分１Ａ
〜１Ｄに参照電極２を移動し、そのときの参照電極２と
被測定電極１との電圧を測定することにより、種々の流
速環境下における電位を求めることができる。従って、
被測定電極１及び参照電極２を上記の如く構成すれば、
一つの被測定電極１であっても、種々の流速での電位を
確実に求めることができる。According to this embodiment, when the liquid is circulated in the electrode 1 to be measured, each portion 1A of the electrode 1 to be measured is
By moving the reference electrode 2 to 1D and measuring the voltage between the reference electrode 2 and the measured electrode 1 at that time, the potentials under various flow velocity environments can be obtained. Therefore,
If the measured electrode 1 and the reference electrode 2 are configured as described above,
Even with one measured electrode 1, the potentials at various flow rates can be reliably obtained.
【００４９】また、一つの参照電極２を第一の部分１Ａ
〜第四の部分１Ｄに夫々移動し、その都度測定すれば、
参照電極２自身がもつ固有のばらつきを考慮しなくても
良い利点がある。Further, one reference electrode 2 is connected to the first portion 1A.
~ If you move to the 4th part 1D and measure each time,
There is an advantage that it is not necessary to consider the inherent variation of the reference electrode 2 itself.
【００５０】実験では、被測定電極１における第一の部
分１Ａは内径を１２ｍｍ，長さを１００ｍｍで、第二の
部分１Ｂは内径を１５ｍｍ，長さを３０ｍｍで、第三の
部分１Ｃは内径を３６ｍｍ，長さを５０ｍｍで、第四の
部分１Ｄは内径を５０ｍｍ，長さを２００ｍｍに形成
し、また参照電極２の大きさは図４を測定した場合のも
のと同寸法のものを用いた。そして、この被測定電極１
内に１００ｄｍ3／ｓの流量で液体を流通し、該被測定
電極１の第一の部分１Ａ〜第四の部分１Ｄに参照電極２
を夫々順次移動した場合、夫々の位置における液体の線
流速は、第一の部分１Ａでは２．８９ｍ／ｓ、第二の部
分１Ｂでは１．０２ｍ／ｓ、第三の部分１Ｃでは０．１
１、第四の部分１Ｄでは０．０５３ｍ／ｓとなり、従っ
て、一つの被測定電極１であっても、上記の形状に形成
すれば、種々の流速を得ることができるのが理解されよ
う。In the experiment, the first portion 1A of the electrode 1 to be measured has an inner diameter of 12 mm and a length of 100 mm, the second portion 1B has an inner diameter of 15 mm and a length of 30 mm, and the third portion 1C has an inner diameter. With a length of 36 mm and a length of 50 mm, the fourth portion 1D is formed with an inner diameter of 50 mm and a length of 200 mm, and the reference electrode 2 has the same size as that used in the measurement of FIG. I was there. And this measured electrode 1
A liquid is circulated at a flow rate of 100 dm 3 / s inside, and the reference electrode 2 is applied to the first portion 1A to the fourth portion 1D of the electrode 1 to be measured.
When moving sequentially, the linear velocity of the liquid at each position is 2.89 m / s in the first portion 1A, 1.02 m / s in the second portion 1B, and 0.1 in the third portion 1C.
It is understood that the first and fourth portions 1D have a flow rate of 0.053 m / s, so that even one electrode 1 to be measured can have various flow velocities if it is formed in the above shape.
【００５１】図７は本発明の第三の実施例を示す。この
場合は、電位測定を種々の流速条件化で同時に行うよう
にしたものである。FIG. 7 shows a third embodiment of the present invention. In this case, the potential measurement is performed simultaneously under various flow rate conditions.
【００５２】具体的に述べると、図７に示すように、元
管１６の上流部（図示左側）には分配管１７Ａが接続さ
れ、該分配管１７に対し第一〜第三からなる三本の電極
部１０１〜１０３の一端が接続され、各電極部１０１〜
１０３の他端に連結部１７Ｂを介し元管１６の下流部
（図示右側）に接続されている。これら第一電極部１０
１〜第三電極部１０３の三本は、互いに内径が異なって
おり、被測定電極１を構成している。More specifically, as shown in FIG. 7, a distribution pipe 17A is connected to the upstream portion (left side in the drawing) of the main pipe 16, and three pipes including first to third pipes are connected to the distribution pipe 17. One end of each of the electrode parts 101 to 103 is connected to each of the electrode parts 101 to 103.
The other end of 103 is connected to the downstream portion (right side in the drawing) of the main pipe 16 via a connecting portion 17B. These first electrode parts 10
The inner diameters of the three first to third electrode portions 103 are different from each other and constitute the measured electrode 1.
【００５３】一方、第一〜第三の各電極部１０１〜１０
３には互いに軸線が一致するよう、固定板４により取付
けられた三本の参照電極２Ａ〜２Ｃが夫々設置され、か
つ各参照電極２Ａ〜２Ｃの液絡部３も参照電極及び各電
極部の軸線上に配置されている。なお図示していない
が、第一〜第三の各電極部１０１〜１０３と各参照電極
２Ａ〜２Ｃとは夫々独立的に設けられた電位測定５に接
続されている。On the other hand, the first to third electrode portions 101 to 10
3, three reference electrodes 2A to 2C attached by a fixing plate 4 are installed so that their axes coincide with each other, and the liquid junction portion 3 of each reference electrode 2A to 2C also has a reference electrode and an electrode portion. It is located on the axis. Although not shown, each of the first to third electrode portions 101 to 103 and each of the reference electrodes 2A to 2C is connected to a potential measurement 5 provided independently of each other.
【００５４】この実施例によれば、元管１６の途中位置
に第一〜第三の各電極部１０１〜１０３が設けられると
共に、各電極部１０１〜１０３内に参照電極２Ａ〜２Ｃ
が設置されているので、種々の流速環境を形成すること
ができると共に、該種々の流速環境下において電位測定
を同時に行うことができる。According to this embodiment, the first to third electrode portions 101 to 103 are provided in the middle of the main tube 16, and the reference electrodes 2A to 2C are provided in the electrode portions 101 to 103.
Is installed, it is possible to form various flow velocity environments and simultaneously perform potential measurement under the various flow velocity environments.
【００５５】図８は本発明の第四の実施例を示す。この
場合は、被測定電極１の外部に参照電極２が設置されて
いる。即ち、この参照電極２は、被測定電極１の外周上
に設置され、液絡部３が被測定電極１の外周部に設けら
れた孔に埋設されている。この場合、液絡部３は、被測
定電極１の内周壁面にそれと同一面となるように埋設さ
れたジルコニアで形成され、被測定電極１の内周壁面よ
り内方には突出しておらず、液体が流通するときに障害
となることはない。なお、参照電極２の内部構造は基本
的には図３に示すものと同様であり、液絡部３の位置の
みが異なっている。また、参照電極２からの電位信号線
６と被測定電位１からの電位信号線１９とは電位測定部
５に接続されている。FIG. 8 shows a fourth embodiment of the present invention. In this case, the reference electrode 2 is installed outside the measured electrode 1. That is, the reference electrode 2 is installed on the outer circumference of the electrode 1 to be measured, and the liquid junction 3 is buried in the hole provided on the outer circumference of the electrode 1 to be measured. In this case, the liquid junction 3 is formed of zirconia embedded in the inner peripheral wall surface of the measured electrode 1 so as to be flush with the inner peripheral wall surface of the measured electrode 1, and does not project inward from the inner peripheral wall surface of the measured electrode 1. , It does not hinder the flow of liquid. The internal structure of the reference electrode 2 is basically the same as that shown in FIG. 3, and only the position of the liquid junction 3 is different. The potential signal line 6 from the reference electrode 2 and the potential signal line 19 from the measured potential 1 are connected to the potential measuring unit 5.
【００５６】この実施例によれば、上述の如く、被測定
電極１の外周上に参照電極２が設置されると共に、該参
照電極２の液絡部３が被測定電極１の内周壁面に埋設さ
れているので、被測定電極１の内部を流れる流量によっ
て線流速が一義的に決まることとなる。その結果、、被
測定電極１の内部で安定した流速を得ることができるの
で、流速を把握した環境下で被測定電極１の電位を測定
することができる。According to this embodiment, as described above, the reference electrode 2 is installed on the outer circumference of the measured electrode 1, and the liquid junction 3 of the reference electrode 2 is formed on the inner peripheral wall surface of the measured electrode 1. Since it is embedded, the linear flow velocity is uniquely determined by the flow rate flowing inside the measured electrode 1. As a result, a stable flow velocity can be obtained inside the measured electrode 1, so that the potential of the measured electrode 1 can be measured in an environment in which the flow velocity is known.
【００５７】図９は本発明の第五の実施例を示し、この
場合は、液体を流通する送液管１８内に電位測定装置の
被測定電極１と参照電極２とが設置されたものである。FIG. 9 shows a fifth embodiment of the present invention. In this case, the measured electrode 1 and the reference electrode 2 of the potential measuring device are installed in the liquid supply pipe 18 through which the liquid flows. is there.
【００５８】即ち、この実施例は、送液管１８の内部に
固定板４により被測定電極１が設置され、該被測定電極
１の軸線が送液管１８の軸線と一致するように配置され
ている。被測定電極１の内部にはその軸線と一致するよ
う、固定板４により参照電極２が設置されている。これ
ら双方の固定板４は電気的な絶縁性をもたせるため、例
えば熱酸化処理されたジルコニウムで形成されており、
その配置形態は第一の実施例（図２）と同様である。That is, in this embodiment, the electrode 1 to be measured is installed inside the liquid feed pipe 18 by the fixing plate 4, and the axis of the electrode 1 to be measured is arranged so as to coincide with the axis of the liquid feed pipe 18. ing. A reference electrode 2 is installed inside the measured electrode 1 by a fixing plate 4 so as to coincide with the axis of the measured electrode 1. Both of these fixing plates 4 are made of, for example, thermally oxidized zirconium in order to have electrical insulation,
The arrangement form is similar to that of the first embodiment (FIG. 2).
【００５９】また、被測定電極１の外周部に設けられた
端子１３により電位信号線１９が引き出される一方、参
照電極２からも電位信号線６が引き出され、これら引き
出された電位信号線１９と電位信号線６とが送液管１８
の外周部から気密を保った状態で挿出して電位測定部５
に接続されている。この場合、電位信号線１９を挿通し
ている絶縁チューブ１２と、電位信号線６を挿通してい
る絶縁チューブ１２とは、送液管１８の外周部に装着さ
れたシール手段２０を貫通し、該シール手段２０により
送液管１８内の液体が外部に漏出しないようにしてい
る。Further, the potential signal line 19 is drawn out by the terminal 13 provided on the outer peripheral portion of the measured electrode 1, while the potential signal line 6 is also drawn out from the reference electrode 2 and these drawn potential signal lines 19 and The potential signal line 6 is the liquid delivery pipe 18
The potential measuring unit 5 is inserted from the outer periphery of the
It is connected to the. In this case, the insulating tube 12 through which the potential signal line 19 is inserted and the insulating tube 12 through which the potential signal line 6 is inserted penetrate the sealing means 20 attached to the outer peripheral portion of the liquid supply pipe 18, The sealing means 20 prevents the liquid in the liquid supply pipe 18 from leaking to the outside.
【００６０】さらに、参照電極２は、本体８の先端部に
円錐状に形成された流路調整部２１が設けられている。
流路調整部２１は、先端部から後端に至るに従い次第に
径が大きくなり、しかもその最大径の部分が本体８の外
径と同一寸法となるように形成されている。なお、参照
電極２の内部構造は図３に示すものと同様である。Further, the reference electrode 2 is provided with a conical flow path adjusting portion 21 at the tip of the main body 8.
The flow path adjusting portion 21 is formed such that the diameter gradually increases from the front end portion to the rear end, and the maximum diameter portion has the same size as the outer diameter of the main body 8. The internal structure of the reference electrode 2 is similar to that shown in FIG.
【００６１】従って、この電位測定装置は、送液管１８
内に互いに軸線が一致するように配置された被測定電極
１と、該被測定電極１内に互いに軸線が一致すると共
に、その軸線上に液絡部３を有する参照電極２とを有し
て構成されている。Therefore, this potential measuring device is provided with the liquid feeding pipe 18
An electrode to be measured 1 arranged so that the axes thereof coincide with each other, and a reference electrode 2 having the liquid junction 3 on the axis thereof while the axes thereof coincide with each other. It is configured.
【００６２】この実施例によれば、送液管１８内に被測
定電極１及び参照電極２が設置されているので、特に送
液管１８と被測定電極１との材質が異なる場合に有効で
あり、送液管１８内に設置することにより確実に電位測
定を行うことができる。According to this embodiment, since the measured electrode 1 and the reference electrode 2 are installed in the liquid feed pipe 18, it is particularly effective when the material of the liquid feed pipe 18 and the measured electrode 1 are different. Yes, the potential can be reliably measured by installing it in the liquid feed pipe 18.
【００６３】また実施例によれば、参照電極２の先端に
流路調整部２１が形成されているので、次の効果があ
る。即ち、参照電極の先端部（上流端部）が図３にて示
す前蓋９の如く平坦形状である場合、被測定電極１内を
流れる液体が参照電極２に達すると、液体は参照電極の
前蓋９に衝突するので、流れが妨げられてしまう。この
とき、前蓋９より下流側の領域では液体の流れに乱流、
あるいはよどみを発生してしまい、参照電極の外周と被
測定電極１の内周間の特定位置によって流速が異なるお
それがある。Further, according to the embodiment, since the flow path adjusting portion 21 is formed at the tip of the reference electrode 2, the following effects can be obtained. That is, when the front end portion (upstream end portion) of the reference electrode has a flat shape like the front lid 9 shown in FIG. 3, when the liquid flowing in the measured electrode 1 reaches the reference electrode 2, the liquid is Since it collides with the front lid 9, the flow is obstructed. At this time, turbulence in the flow of the liquid occurs in the region downstream of the front lid 9,
Alternatively, stagnation may occur, and the flow velocity may vary depending on a specific position between the outer circumference of the reference electrode and the inner circumference of the measured electrode 1.
【００６４】本実施例では、上述の如く、参照電極２の
先端に円錐状の流路調整部２１が形成されているので、
液体の流れがスムースになり、そのため、参照電極２の
外周と被測定電極１の内周との間で乱流あいるはよどみ
等が発生するのを防止することができ、安定したかつ確
実な電位測定を行うことができる。この場合、被測定電
極１が送液管１８内に設置された例のみならず、送液管
１８内に設置しないで使用するときにも同様の効果を得
ることができるのは勿論である。In this embodiment, as described above, since the conical flow path adjusting portion 21 is formed at the tip of the reference electrode 2,
The flow of the liquid becomes smooth, so that it is possible to prevent the occurrence of turbulent flow or stagnation between the outer circumference of the reference electrode 2 and the inner circumference of the measured electrode 1, and to provide a stable and reliable Potential measurements can be made. In this case, it is needless to say that the same effect can be obtained not only when the electrode 1 to be measured is installed in the liquid supply pipe 18 but also when the electrode 1 is used without being installed in the liquid supply pipe 18.
【００６５】なお、本例では、送液管１８内に被測定電
極１と参照電極２からなる一組のものを設置した例を図
示したが、内径の異なる被測定電極１と、それに対応し
て形成された参照電極２とからなる複数組のものを、送
液管１８内に並列に配置すれば、同一の場所でかつ同時
に種々の流速を形成することができると共に、種々の流
速環境下での電位測定が可能となる。さらに、送液管１
８内の同一場所で材質の異なる電極によって電位測定を
同時に行う場合、互いに材質の異なる被測定電極と、そ
の内部に設置される参照電極との組を複数用意し、これ
らの組を送液管１８内に設置することにより、実現する
ことができる。In this example, an example in which one set of the measured electrode 1 and the reference electrode 2 is installed in the liquid supply pipe 18 is shown, but the measured electrodes 1 having different inner diameters and corresponding electrodes By arranging a plurality of sets of the reference electrodes 2 formed in parallel with each other in the liquid delivery pipe 18, various flow velocities can be formed at the same place and at the same time, and under various flow velocity environments. It becomes possible to measure the electric potential at. Furthermore, the liquid delivery pipe 1
When the potentials are simultaneously measured by electrodes made of different materials at the same place in 8, a plurality of pairs of electrodes to be measured having different materials and reference electrodes installed therein are prepared, and these pairs are connected to the liquid feed pipe. It can be realized by installing in 18.
【００６６】以上述べたこれまでの実施例では、参照電
極２の液絡部３とこれに対向する被測定電極１の内周壁
間の線流速が、液体流量と被測定電極１と参照電極２の
形状で決まり、何れも、被測定電極１の形状（径）を途
中で変えることができない例を示した。これは被測定電
極１の参照電極２の形状は任意に変化させることができ
ないからである。In the above-described embodiments, the linear flow velocity between the liquid junction 3 of the reference electrode 2 and the inner peripheral wall of the measured electrode 1 facing the liquid junction 3 is determined by the liquid flow rate and the measured electrode 1 and the reference electrode 2. The example shows that the shape (diameter) of the measured electrode 1 cannot be changed on the way. This is because the shape of the reference electrode 2 of the measured electrode 1 cannot be changed arbitrarily.
【００６７】しかし、被測定電極１の上流側と下流側と
のすくなくとも何れか一方に、流量を制御し得るポンプ
手段を設け、あるいは流量調整手段を設けることによ
り、被測定電極１を流れる液体の流量を任意に変えるこ
とができるので、結果として線流速を調節することが可
能になる。However, by providing the pump means capable of controlling the flow rate or the flow rate adjusting means on at least one of the upstream side and the downstream side of the electrode to be measured 1, the liquid flowing through the electrode to be measured 1 is provided. Since the flow rate can be changed arbitrarily, the linear flow velocity can be adjusted as a result.
【００６８】逆に全体の構造上、流量を変化させること
ができいな場合、流量が時間と共に変化する場合、実施
例１及び２のようにすることもできるが、流量を知る手
段として、流量計あるいは流速計を被測定電極１の上流
側と下流側との一方に設けることにより、正確な流速を
知ることができる。On the contrary, in the case where the flow rate cannot be changed due to the entire structure, or when the flow rate changes with time, it can be carried out as in the first and second embodiments. Alternatively, by providing a flow meter on one of the upstream side and the downstream side of the electrode 1 to be measured, the accurate flow rate can be known.
【００６９】図１０は本発明の他の実施例を示す。この
場合は、本願発明の電位測定装置を火力発電プラントに
適用したものである。火力発電プラントは、図１０に示
すように、高圧加熱蒸気が供給されることによってター
ビン２３が駆動され、そのタービン２３の駆動によって
発電機２４が発電する。一方、タービン２３を駆動した
高圧加熱蒸気が復水器２５により復水され、復水は復水
ポンプ３４により復水ろ過脱塩器２６に送り込まれて脱
塩された後、低圧給水加熱器２７，給水ポンプ２８を経
て高圧給水加熱器２９に送り込まれることにより高圧化
し、次いで火炉２２を経て高圧加熱蒸気となることによ
りタービン２３に送られる。FIG. 10 shows another embodiment of the present invention. In this case, the potential measuring device of the present invention is applied to a thermal power plant. As shown in FIG. 10, in the thermal power plant, the turbine 23 is driven by the supply of high-pressure heating steam, and the generator 24 generates power by driving the turbine 23. On the other hand, the high-pressure heating steam that has driven the turbine 23 is condensed by the condenser 25, and the condensed water is sent to the condensate filtration desalination unit 26 by the condensate pump 34 to be desalted, and then the low-pressure feed water heater 27. The high pressure water is supplied to the high pressure feed water heater 29 via the water supply pump 28 to increase the pressure, and then the high pressure heating steam is passed through the furnace 22 to be sent to the turbine 23.
【００７０】実施例では、高圧給水加熱器２９と火炉２
２とを結ぶ配管の途中位置に分岐管３６が設けられ、該
分岐管３６の途中位置に電位測定装置が設置される。こ
の場合、電位測定装置の被測定電極１，参照電極２，電
位測定部５は、図２にて示すものと同様であるので、そ
の説明を省略する。In the embodiment, the high pressure feed water heater 29 and the furnace 2
A branch pipe 36 is provided in the middle of the pipe connecting the two, and a potential measuring device is installed in the middle of the branch pipe 36. In this case, the measured electrode 1, the reference electrode 2, and the potential measuring unit 5 of the potential measuring device are the same as those shown in FIG.
【００７１】また、分岐管３６において、被測定電極１
より下流側には流量可変式の高圧ポンプ３０，流量調節
弁３１，流量計３２が順次設けられている。さらに、電
位測定部５の出力部には薬品注入部３３が接続されてい
る。該薬品注入部３３は、電位測定部５からの出力に基
づきアンモニアおよび酸素ガスを給水系に供給、即ち、
低圧給水加熱器２７と復水ろ過脱塩器２６とを結ぶ配管
３７に供給するようにしている。Further, in the branch pipe 36, the measured electrode 1
On the further downstream side, a variable flow type high pressure pump 30, a flow rate control valve 31, and a flow meter 32 are sequentially provided. Further, the chemical injection part 33 is connected to the output part of the potential measurement part 5. The chemical injection part 33 supplies ammonia and oxygen gas to the water supply system based on the output from the potential measuring part 5, that is,
The low pressure feed water heater 27 and the condensate water filter desalting device 26 are connected to a pipe 37.
【００７２】実施例では、上述の如く、電位測定装置を
有する分岐管３６，該分岐管３６の下流側に高圧ポンプ
３０，流量調節弁３１が夫々設けられているので、高圧
ポンプ３０の吐出量を変えたり、流量調節弁３１の開度
を変えたりすることにより、被測定電極１内を通過する
高圧水の流量を任意に変えることができる。しかも、流
量計３２をも有し、該流量計３２によって高圧水の流量
を検出できるので、高圧給水加熱器２９から供給される
高圧水の流量が時間と共に変化する場合等があっても、
これに拘わることなく正確な流速を知ることができる。In the embodiment, as described above, since the branch pipe 36 having the potential measuring device and the high pressure pump 30 and the flow rate adjusting valve 31 are provided on the downstream side of the branch pipe 36, respectively, the discharge amount of the high pressure pump 30. Or the opening of the flow rate control valve 31 can be changed to arbitrarily change the flow rate of the high-pressure water passing through the electrode 1 to be measured. Moreover, since the flow meter 32 is also provided and the flow rate of the high pressure water can be detected by the flow meter 32, even if the flow rate of the high pressure water supplied from the high pressure feed water heater 29 changes with time,
It is possible to know the accurate flow velocity without being concerned with this.
【００７３】その結果、被測定電極１と参照電極２との
形状を変化させることができなくとも、高圧水の流量を
任意に変えることができ、また流量が時間と共に変化す
る等の場合でも、正確な流速を知ることができるので、
正確な電位測定を確実に実現することができ、腐食電位
の評価を正確に行える。As a result, even if the shapes of the measured electrode 1 and the reference electrode 2 cannot be changed, the flow rate of the high-pressure water can be arbitrarily changed, and even when the flow rate changes with time, Since you can know the accurate flow velocity,
Accurate measurement of the potential can be reliably realized, and the corrosion potential can be accurately evaluated.
【００７４】さらに、実施例においては次のような効果
もある。一般に、火力発電プラントの水処理方法の一つ
として複合水処理方法（ＣＷＴ）がある。該複合水処理
方法では、配管，蒸発管表面にヘマタイト（α−Ｆｅ2
Ｏ3）を生成させ、給水系２７〜２９および火炉２３の
構造材料の腐食溶出，付着を低減させる目的でしようさ
れている。このとき、配管，蒸発管の腐食電位はある一
定電位以上になることが知られている。高圧給水加熱器
２９の出口温度は約２８０℃であり、その場所での酸素
量がヘマタイト生成に対し不足するときの腐食電位は、
−０．５Ｖｖｓ．ＳＨＥ前後となっている。一方、ヘマ
タイトが安定に存在できるような酸素存在下では腐食電
位は約０．２Ｖｖｓ．ＳＨＥ以上である。Further, the embodiment has the following effects. Generally, there is a combined water treatment method (CWT) as one of the water treatment methods for a thermal power plant. In the composite water treatment method, hematite (α-Fe 2
It is used for the purpose of generating O 3 ) and reducing corrosion elution and adhesion of structural materials of the water supply systems 27 to 29 and the furnace 23. At this time, it is known that the corrosion potential of the pipe and the evaporation pipe becomes a certain constant potential or more. The outlet temperature of the high-pressure feed water heater 29 is about 280 ° C., and the corrosion potential when the amount of oxygen at that location is insufficient for hematite formation is:
-0.5 Vvs. It is around SHE. On the other hand, in the presence of oxygen such that hematite can exist stably, the corrosion potential is about 0.2 Vvs. It is more than SHE.
【００７５】そこで、ヘマタイトが安定に存在し、酸素
存在環境を生成するよう給水の水質を制御するため、薬
品注入部３３が電位測定部５からの電位値に基づき酸素
およびアンモニアを低圧給水加熱器２７の上流側に供給
し、分岐管３６側の電位が意って位置以上になるように
制御保持されることとなる。即ち、ヘマタイトが安定に
存在できる電位となるように腐食電位を保持することが
できるので、酸素量を過不足なく制御することが可能と
なり、それだけプラントの信頼性を高めることができる
ばかりでなく、配管の腐食防止を図ることによりその分
だけ経済性に優れる効果もある。Therefore, in order to control the water quality of the feed water so that hematite is stably present and an oxygen-existing environment is generated, the chemical injection unit 33 supplies oxygen and ammonia to the low-pressure feed water heater based on the potential value from the potential measuring unit 5. It is supplied to the upstream side of 27 and is controlled and held so that the potential on the side of the branch pipe 36 is higher than the desired position. That is, since it is possible to maintain the corrosion potential so that hematite has a potential that can be stably present, it becomes possible to control the oxygen amount without excess or deficiency, and not only can the reliability of the plant be increased, By preventing the corrosion of the pipes, there is also an effect that is more economical.
【００７６】なお、本実施例では、薬品注入部３３が電
位測定部５からの出力に基づき低圧給水加熱器２７の上
流側に薬品を注入するように構成した例を示したが、次
のように構成してもよい。例えば、薬品注入部３３と電
位測定部５との間に制御部を介装し、該制御部が電位測
定部５からの出力に基づき演算し、薬品注入部３３に指
令することにより、薬品注入部３３が注入動作するよう
に構成してもよい。この場合、制御部としては、電位測
定部５からの出力により薬品注入部３３を制御するのみ
ならず、流量計３２からの信号を取り込んだり、高圧ポ
ンプ３０の回転数，流量調節弁３１の開度を制御するよ
うに構成することもできる。In the present embodiment, an example is shown in which the chemical injection section 33 is configured to inject chemicals to the upstream side of the low-pressure feed water heater 27 based on the output from the potential measuring section 5, but the following is given. You may comprise. For example, by inserting a control unit between the chemical injection unit 33 and the electric potential measurement unit 5, the control unit calculates based on the output from the electric potential measurement unit 5, and instructs the chemical injection unit 33 to inject the chemical. The part 33 may be configured to perform an injection operation. In this case, the control section not only controls the chemical injection section 33 by the output from the potential measuring section 5, but also takes in a signal from the flow meter 32, opens the high-pressure pump 30 and the flow rate control valve 31. It can also be configured to control the degree.
【００７７】これまで述べた幾つの実施例では、被測定
電極１の軸線に対し参照電極２の軸線を一致させた例を
示したが、これに限定されるものではなく、被測定電極
１内に設置された参照電極２の液絡部３と、被測定電極
１の内周壁における前記液絡部３と対向する位置との間
を流れる液体の流速が、予め把握できる形状であればよ
い。即ち、被測定電極１に参照電極２が設置されたと
き、被測定電極１の軸線に対し参照電極２の軸線が平行
であってもよいのは勿論である。In some of the embodiments described above, the axis of the reference electrode 2 is aligned with the axis of the measured electrode 1, but the invention is not limited to this. It is sufficient that the flow velocity of the liquid flowing between the liquid junction 3 of the reference electrode 2 installed at the position and the position on the inner peripheral wall of the measured electrode 1 facing the liquid junction 3 can be grasped in advance. That is, when the reference electrode 2 is installed on the measured electrode 1, the axis of the reference electrode 2 may be parallel to the axis of the measured electrode 1.
【００７８】また、参照電極２については、本実施例で
は、０．１Ｍ塩化カリウム溶液を含む銀／塩化銀タイプ
を用いた例を示したが、参照電極自身のもつ電位が時
間，環境の変化により変わらないものであれば、何れの
タイプを用いてもよい。As for the reference electrode 2, an example of using a silver / silver chloride type containing a 0.1 M potassium chloride solution was shown in this embodiment, but the potential of the reference electrode itself changes with time and environment. Any type may be used as long as it does not change.
【００７９】さらに図示実施例では、参照電極２の外周
部において軸方向の中間部に液絡部３が配置された例を
示したが、液絡部３の位置は、参照電極２の先端部およ
び後端部のように流速が変化する箇所から十分離れた位
置であって、また参照電極２が設置されていない部分で
かつ被測定電極１の電位の影響をうけにくい箇所であれ
ば何れであってもよい。しかも、液絡部３を参照電極１
において１個だけ設けられた例を示したが、上述した条
件のもとであれば参照電極本体８の軸方向に複数個、あ
るいは本体８の外周部に複数個設けてもよい。Further, in the illustrated embodiment, the example in which the liquid junction 3 is arranged at the intermediate portion in the axial direction on the outer peripheral portion of the reference electrode 2 is shown. However, the position of the liquid junction 3 is at the tip of the reference electrode 2. And a position such as a rear end which is sufficiently distant from a position where the flow velocity changes, and which is a part where the reference electrode 2 is not installed and is not easily affected by the potential of the measured electrode 1. It may be. Moreover, the liquid junction 3 is connected to the reference electrode 1
In the above, an example in which only one electrode is provided is shown, but a plurality of electrodes may be provided in the axial direction of the reference electrode main body 8 or a plurality of them may be provided on the outer peripheral portion of the main electrode 8 under the above-mentioned conditions.
【００８０】[0080]
【発明の効果】以上述べたように、本発明の請求項１〜
４によれば、内径が軸方向に沿い同一寸法をなす円筒状
の被測定電極と、該被測定電極の内部に設置され、外径
が軸方向に沿い同一寸法をなし且つ電位感知口としての
液絡部を設けた円柱状の参照電極と、参照電極の液絡部
の電圧に基づき被測定電極の電位を測定する電位測定部
とを有し、前記参照電極を、該参照電極の外周と前記被
測定電極の内周との間に形成される流路が軸方向におけ
る何れの位置でも同一の間隙を有するように、当該参照
電極の軸線が被測定電極の軸線と平行に配置し、前記液
絡部を、前記参照電極の外周部の軸線上であり且つその
軸線の略中央部に配置して構成したので、被測定電極の
内側と参照電極間で液体がばらつくことなく均一に流れ
る状態を形成し、液体の流速を把握できることにより、
正確な電位測定を実現することができる結果、腐食電位
の評価を正確に行えるという効果がある。この効果は請
求項７によっても同様である。As described above, the claims 1 to 3 of the present invention are as follows.
According to 4, the inner diameter of the cylindrical electrode to be measured has the same dimension along the axial direction and the inner diameter of the electrode to be measured, and the outer diameter has the same dimension along the axial direction and serves as a potential sensing port. A columnar reference electrode provided with a liquid junction, and a potential measuring unit for measuring the potential of the electrode under measurement based on the voltage of the liquid junction of the reference electrode, the reference electrode, the outer periphery of the reference electrode Said cover
The flow path formed between the inner circumference of the measurement electrode and the
Reference so that they have the same gap at all positions.
The axis of the electrode is placed parallel to the axis of the electrode to be measured,
A contact portion on the axis of the outer periphery of the reference electrode and
Since it is arranged near the center of the axis, it is possible to form a state in which the liquid flows evenly between the inside of the measured electrode and the reference electrode without variation, and by being able to grasp the flow velocity of the liquid,
As a result of being able to realize accurate potential measurement, there is an effect that the corrosion potential can be evaluated accurately. This effect is the same as in claim 7.
【００８１】また、請求項５によれば、参照電極の軸線
が被測定電極の軸線に一致し、より均一な流速を得るこ
とができ、より正確な電位測定を実現できる結果、腐食
電位の評価をいっそう正確に行い得る効果があり、請求
項６によれば、流路調整部により乱流あるいはよどみ等
が発生するのを防止することができ、安定したかつ確実
な電位測定を行うことができる効果がある。さらに、請
求項８によれば、ポンプと液体流量測定手段と液体流速
測定手段との何れかを有することにより、種々の流速の
環境下で電位測定を実現し得る効果がある。Further, according to claim 5, the axis of the reference electrode coincides with the axis of the electrode to be measured, a more uniform flow velocity can be obtained, and more accurate potential measurement can be realized. As a result, the corrosion potential is evaluated. According to claim 6, turbulent flow or stagnation can be prevented from occurring, and stable and reliable potential measurement can be performed. effective. Further, according to claim 8, by having any of the pump, the liquid flow rate measuring means, and the liquid flow velocity measuring means, there is an effect that the potential measurement can be realized under the environment of various flow velocity.
【００８２】そして、請求項９によれば、液体の水質を
改善でき、それだけプラントの信頼性を高めることがで
きるばかりでなく、配管の腐食防止を図ることによりそ
の分だけ経済性に優れる効果もある。請求項１０によれ
ば、種々の流速の環境下で電位測定を実現し得ると共
に、流速が時間と共に変化する場合でも容易に対処する
ことができる効果がある。According to the ninth aspect, not only the water quality of the liquid can be improved and the reliability of the plant can be improved by that much, but also the corrosion of the pipe can be prevented, and accordingly, the effect of being excellent in the economical efficiency can be obtained. is there. According to the tenth aspect, there is an effect that the potential measurement can be realized under the environment of various flow velocities and the case where the flow velocities change with time can be easily dealt with.
【図１】本発明による電位測定装置の概念を示す被測定
電極の端面図（ａ），軸方向の断面図（ｂ），被測定電
極内における各部の位置と液体の流速との関係を示す説
明図（ｃ）。FIG. 1 is an end view (a) of an electrode to be measured showing the concept of a potential measuring device according to the present invention, a sectional view (b) in the axial direction, showing the relationship between the position of each part in the electrode to be measured and the flow velocity of a liquid. Explanatory drawing (c).
【図２】本発明による電位測定装置を示す被測定電極の
端面図（ａ），軸方向の説明用断面図（ｂ）。FIG. 2 is an end view (a) of an electrode to be measured showing an electric potential measuring device according to the present invention, and an axial cross-sectional view (b) for explanation.
【図３】参照電極の内部構造を示す説明図。FIG. 3 is an explanatory diagram showing an internal structure of a reference electrode.
【図４】本発明による電位測定装置における電位測定部
の測定結果を示す説明図。FIG. 4 is an explanatory diagram showing a measurement result of a potential measuring unit in the potential measuring device according to the present invention.
【図５】金属の分極曲線を示す説明図。FIG. 5 is an explanatory view showing a polarization curve of metal.
【図６】本発明の第二の実施例を示す説明用断面図。FIG. 6 is an explanatory sectional view showing a second embodiment of the present invention.
【図７】本発明の第三の実施例を示す説明用断面図。FIG. 7 is an explanatory sectional view showing a third embodiment of the present invention.
【図８】本発明の第四の実施例を示す被測定電極と参照
電極との側面図（ａ）及び全体を示す説明用断面図
（ｂ）。FIG. 8 is a side view (a) of an electrode to be measured and a reference electrode according to a fourth embodiment of the present invention and an explanatory cross-sectional view (b) showing the whole.
【図９】本発明の第五の実施例を示し、電位測定装置を
送液管に設置した状態を示す説明用断面図。FIG. 9 is an explanatory cross-sectional view showing a fifth embodiment of the present invention, showing a state in which a potential measuring device is installed in a liquid feed pipe.
【図１０】本発明を火力発電プラントに適用した実施例
を示す配管系統図。FIG. 10 is a piping system diagram showing an embodiment in which the present invention is applied to a thermal power plant.
１…被測定電極、２…参照電極、３液絡部、５…電位測
定部、６…参照電極の電位信号線、１３…被測定電極の
電位信号線、１６…元管、１８…送液管、２７〜２９…
給水系、２２…火炉、３０…高圧ポンプ、３１…流量調
節弁、３２…流量計、３３…薬品注入部、３６…分岐
管。DESCRIPTION OF SYMBOLS 1 ... Electrode to be measured, 2 ... Reference electrode, 3 liquid junction part, 5 ... Potential measuring part, 6 ... Potential signal line of reference electrode, 13 ... Potential signal line of measured electrode, 16 ... Main pipe, 18 ... Liquid transfer Tubes, 27-29 ...
Water supply system, 22 ... Furnace, 30 ... High-pressure pump, 31 ... Flow control valve, 32 ... Flow meter, 33 ... Chemical injection section, 36 ... Branch pipe.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高橋 卓也 茨城県日立市大みか町七丁目１番１号 株式会社 日立製作所 日立研究所内 (72)発明者 赤嶺 和彦 茨城県日立市幸町三丁目１番１号 株式 会社 日立製作所 日立工場内 (72)発明者 清水 暢夫 茨城県日立市幸町三丁目１番１号 株式 会社 日立製作所 日立工場内 (56)参考文献 特開 平４−83153（ＪＰ，Ａ) 特開 平８−114569（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 27/26 351 G21C 17/003 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuya Takahashi 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Kazuhiko Akamine 3-chome, Sachi-cho, Hitachi-shi, Ibaraki No. 1 Hitachi Ltd., Hitachi factory (72) Inventor Nobuo Shimizu 3-1-1 1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd., Hitachi factory (56) Reference JP-A-4-83153 (JP, A) ) JP-A-8-114569 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) G01N 27/26 351 G21C 17/003
Claims (10)
状の被測定電極と、該被測定電極の内部に設置され、外
径が軸方向に沿い同一寸法をなし且つ電位感知口として
の液絡部を設けた円柱状の参照電極と、参照電極の液絡
部の電圧に基づき被測定電極の電位を測定する電位測定
部とを有し、 前記参照電極は、該参照電極の外周と前記被測定電極の
内周との間に形成される流路が軸方向における何れの位
置でも同一の間隙を有するように、当該参照電極の軸線
が被測定電極の軸線と平行に配置されており、 前記液絡部は、前記参照電極の外周部の軸線上であり且
つその軸線の略中央部に配置されている ことを特徴とす
る電位測定装置。1. A cylinder whose inside diameter is the same along the axial direction.
-Shaped electrode to be measured and installed inside the electrode to be measured and outside
Same diameter along the axial directionNone andAs a potential sensing port
Columnar reference electrode with the liquid junction part of
Potential measurement to measure the potential of the measured electrode based on the voltage of the part
Part andHave, The reference electrode is the outer circumference of the reference electrode and the measured electrode.
The axial flow path formed between the inner circumference and
Axis of the reference electrode so that the same gap is maintained even when placed
Is arranged parallel to the axis of the electrode to be measured, The liquid junction is on the axis of the outer periphery of the reference electrode and
It is located approximately in the center of its axis Characterized by
Potential measuring device.
する形状をなす円筒状の被測定電極と、該被測定電極の
内部に設置され、外径が軸方向に沿い同一寸法をなすと
共に、軸線が被測定電極の軸線と平行に配置され、かつ
電位感知口としての液絡部を設けた円柱状の参照電極
と、参照電極の液絡部の電圧に基づき被測定電極の電位
を測定する電位測定部と、参照電極を被測定電極内の所
望位置に軸方向に移動させる手段とを有することを特徴
とする電位測定装置。2. A cylindrical electrode to be measured, the inner diameter of which gradually increases in a stepwise manner along the axial direction, and the inner diameter of the electrode to be measured is set inside the electrode to be measured. At the same time, the axis of the reference electrode is arranged parallel to the axis of the electrode to be measured, and a cylindrical reference electrode provided with a liquid junction as a potential sensing port, and the potential of the electrode to be measured based on the voltage of the liquid junction of the reference electrode. An electric potential measuring device comprising: an electric potential measuring unit for measuring; and a means for axially moving a reference electrode to a desired position in an electrode to be measured.
複数並列に接続され、かつ各々が互いに内径が異なる円
筒状の被測定電極と、各被測定電極の内部にそれぞれ設
置され、外径が軸方向に沿い同一寸法をなすと共に、軸
線が各被測定電極の軸線と平行に配置され、かつ電位感
知口としての液絡部を設けた複数からなる円柱状の参照
電極と、各参照電極の液絡部の電圧に基づき対応する被
測定電極の電位を測定する電位測定部とを有することを
特徴とする電位測定装置。3. A cylindrical electrode to be measured, which is connected in parallel to each other at a midpoint of a main pipe through which liquid flows, and has inner diameters different from each other. Have the same dimension along the axial direction, the axis is arranged in parallel with the axis of each electrode to be measured, and a plurality of cylindrical reference electrodes provided with a liquid junction portion as a potential sensing port, and each reference electrode. And a potential measuring unit that measures the potential of the corresponding electrode under measurement based on the voltage of the liquid junction.
設置され、かつ内径が軸方向に沿い同一寸法をなす円筒
状の被測定電極と、該被測定電極の内部に設置され、外
径が軸方向に沿い同一寸法をなし且つ電位感知口として
の液絡部を設けた円柱状の参照電極と、参照電極の液絡
部の電圧に基づき被測定電極の電位を測定する電位測定
部とを有し、 前記参照電極は、該参照電極の外周と前記被測定電極の
内周との間に形成される流路が軸方向における何れの位
置でも同一の間隙を有するように、当該参照電 極の軸線
が被測定電極の軸線と平行に配置されており、 前記液絡部は、前記参照電極の外周部の軸線上であり且
つその軸線の略中央部に配置されている ことを特徴とす
る電位測定装置。4. An intermediate position in a liquid delivery pipe for circulating a liquid
A cylinder that is installed and has the same inner diameter along the axial direction.
-Shaped electrode to be measured and installed inside the electrode to be measured and outside
Same diameter along the axial directionNone andAs a potential sensing port
Columnar reference electrode with the liquid junction part of
Potential measurement to measure the potential of the measured electrode based on the voltage of the part
Part andHave, The reference electrode is the outer circumference of the reference electrode and the measured electrode.
The axial flow path formed between the inner circumference and
The reference voltage so that the Pole axis
Is arranged parallel to the axis of the electrode to be measured, The liquid junction is on the axis of the outer periphery of the reference electrode and
It is located approximately in the center of its axis Characterized by
Potential measuring device.
の軸線に一致して配置されていることを特徴とする請求
項１〜４の何れか一項に記載の電位測定装置。5. The potential measuring device according to claim 1, wherein the reference electrode is arranged with its axis aligned with the axis of the electrode to be measured.
状の流路調整手段を形成していることを特徴とする請求
項１〜４の何れか一項に記載の電位測定装置。6. The potential measuring device according to claim 1, wherein the reference electrode has a conical flow path adjusting means formed at an upstream end thereof.
状の被測定電極と、該被測定電極の外周上に設置され且
つ電位感知口としての液絡部を設けた参照電極と、参照
電極の液絡部の電圧に基づき被測定電極の電位を測定す
る電位測定部とを有し、 前記液絡部は、前記液絡部の一面と前記被測定電極の内
周壁面とが同一面となるように前記被測定電極の内周壁
面に埋設されている ことを特徴とする電位測定装置。7. A cylinder whose inside diameter is the same along the axial direction.
-Shaped electrode to be measured and installed on the outer circumference of the electrode to be measuredAnd
OneA reference electrode provided with a liquid junction as a potential sensing port, and a reference
Measure the potential of the measured electrode based on the voltage at the liquid junction of the electrode.
The potential measuring unitHave, The liquid junction part is provided on the one surface of the liquid junction part and the electrode to be measured.
The inner peripheral wall of the electrode to be measured so that it is flush with the peripheral wall.
Is buried in the surface A potential measuring device characterized by the above.
一方に、液体を供給するポンプと、液体の流量を測定す
る手段と、液体の流速を測定する手段との何れかを有す
ることを特徴とする請求項１〜４の何れか一項に記載の
電位測定装置。8. A pump for supplying a liquid, a means for measuring the flow rate of the liquid, and a means for measuring the flow velocity of the liquid are provided on either the upstream side or the downstream side of the electrode to be measured. The potential measuring device according to any one of claims 1 to 4, characterized in that.
給水加熱手段からの高圧水をさらに加熱し、蒸気を生成
する手段とを有する発電プラントにおいて、給水加熱手
段と蒸気を生成する手段との間の配管の途中位置に接続
された分岐管と、該分岐管の途中位置に接続され、内径
が軸方向に沿い同一寸法をなす円筒状の被測定電極と、
該被測定電極の内部に設置され、外径が軸方向に沿い同
一寸法をなすと共に、軸線が被測定電極の軸線と平行に
配置され、かつ電位感知口としての液絡部を設けた円柱
状の参照電極と、参照電極の液絡部の電圧に基づき被測
定電極の電位を測定する電位測定部と、該電位測定部の
出力に基づき給水加熱手段の上流側に水質改善用の薬品
を注入する薬品注入部とを有する電位測定装置を備えた
ことを特徴とする発電プラントの配管系統。9. A power plant having a feed water heating means for heating feed water under high pressure and a means for further heating high pressure water from the feed water heating means to generate steam , and feed water heating means and means for generating steam. a branch pipe connected to the intermediate position of the piping between, is connected to the middle position of the branch pipe, a cylindrical measured electrodes forming the same dimensions along an inner diameter in the axial direction,
A cylindrical column which is installed inside the electrode to be measured, has an outer diameter of the same dimension along the axial direction, is arranged in parallel with the axis of the electrode to be measured, and has a liquid junction as a potential sensing port. Of the reference electrode, the potential measuring section for measuring the potential of the measured electrode based on the voltage of the liquid junction of the reference electrode, and the chemical for improving the water quality is injected into the upstream side of the feed water heating means based on the output of the potential measuring section. A piping system of a power plant, comprising: a potential measuring device having a chemical injection part that operates.
該給水加熱手段からの高圧水をさらに加熱し、蒸気を生
成する手段とを有する発電プラントにおいて、給水加熱
手段と蒸気を生成する手段との間の配管の途中位置に接
続された分岐管と、該分岐管の途中位置に接続され、内
径が軸方向に沿い同一寸法をなす円筒状の被測定電極
と、該被測定電極の内部に設置され、外径が軸方向に沿
い同一寸法をなすと共に、軸線が被測定電極の軸線と平
行に配置され、かつ電位感知口としての液絡部を設けた
円柱状の参照電極と、参照電極の液絡部の電圧に基づき
被測定電極の電位を測定する電位測定部と、該電位測定
部の出力に基づき給水加熱手段の上流側に水質改善用の
薬品を注入する薬品注入部と、分岐管における被測定電
極より上流側と下流側との何れかに設けられ、かつ少な
くとも液体供給用ポンプ手段と液体の流量測定手段と液
体の流速測定手段との何れか一方の手段とを有する電位
測定装置を備えたことを特徴とする発電プラントの配管
系統。10. A feed water heating means for heating feed water under high pressure,
In a power plant having means for further heating high-pressure water from the feed water heating means to generate steam, a branch pipe connected to an intermediate position of a pipe between the feed water heating means and the steam generating means , A cylindrical electrode to be measured, which is connected to an intermediate position of the branch pipe and has the same inner diameter along the axial direction, and is installed inside the electrode to be measured, and the outer diameter has the same dimension along the axial direction. , A cylindrical reference electrode whose axis is arranged parallel to the axis of the electrode to be measured and has a liquid junction as a potential sensing port, and the potential of the electrode to be measured is measured based on the voltage of the liquid junction of the reference electrode. Potential measuring section, a chemical injection section for injecting a chemical for water quality improvement on the upstream side of the feed water heating means based on the output of the potential measuring section, and either the upstream side or the downstream side of the measured electrode in the branch pipe. And at least a liquid supply port Plumbing power plant, characterized in that it comprises a potential measurement apparatus having either one of the means of the flop means and the liquid flow rate measuring means and the velocity measuring means of the liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17514896A JP3400913B2 (en) | 1996-07-04 | 1996-07-04 | Potential measurement device and piping system of power plant |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17514896A JP3400913B2 (en) | 1996-07-04 | 1996-07-04 | Potential measurement device and piping system of power plant |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1019825A JPH1019825A (en) | 1998-01-23 |
| JP3400913B2 true JP3400913B2 (en) | 2003-04-28 |
Family
ID=15991121
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17514896A Expired - Fee Related JP3400913B2 (en) | 1996-07-04 | 1996-07-04 | Potential measurement device and piping system of power plant |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3400913B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7060177B2 (en) * | 2003-03-28 | 2006-06-13 | General Electric Company | Method and apparatus for measuring electrochemical corrosion potential inside small shallow cracks |
| JP5264402B2 (en) * | 2008-10-14 | 2013-08-14 | 日本原子力発電株式会社 | Corrosion potential measuring device |
| JP5519920B2 (en) * | 2008-10-14 | 2014-06-11 | 日本原子力発電株式会社 | PWR power plant secondary cooling system water treatment system and method |
| JP2011149764A (en) * | 2010-01-20 | 2011-08-04 | Hitachi-Ge Nuclear Energy Ltd | Method for reducing dose of nuclear power plant component member |
| JP6249266B2 (en) * | 2013-06-03 | 2017-12-20 | 三浦工業株式会社 | Water quality monitor |
| JP6096682B2 (en) * | 2014-01-20 | 2017-03-15 | 東京瓦斯株式会社 | Pitting potential monitoring reference electrode, pitting potential monitoring device |
| CN111118502B (en) * | 2020-01-16 | 2023-03-21 | 西安热工研究院有限公司 | Small-caliber heat exchange tube cathode protection potential measuring device and using method |
-
1996
- 1996-07-04 JP JP17514896A patent/JP3400913B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1019825A (en) | 1998-01-23 |
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