JP2015206615A - Water level detector - Google Patents

Water level detector Download PDF

Info

Publication number
JP2015206615A
JP2015206615A JP2014085706A JP2014085706A JP2015206615A JP 2015206615 A JP2015206615 A JP 2015206615A JP 2014085706 A JP2014085706 A JP 2014085706A JP 2014085706 A JP2014085706 A JP 2014085706A JP 2015206615 A JP2015206615 A JP 2015206615A
Authority
JP
Japan
Prior art keywords
water level
probe
current
level detection
containment vessel
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.)
Granted
Application number
JP2014085706A
Other languages
Japanese (ja)
Other versions
JP6479334B2 (en
Inventor
雅人 大庭
Masahito Oba
雅人 大庭
浩幸 右近
Hiroyuki Ukon
浩幸 右近
翔平 長谷川
Shohei Hasegawa
翔平 長谷川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Priority to JP2014085706A priority Critical patent/JP6479334B2/en
Publication of JP2015206615A publication Critical patent/JP2015206615A/en
Application granted granted Critical
Publication of JP6479334B2 publication Critical patent/JP6479334B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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

Landscapes

  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
  • Monitoring And Testing Of Nuclear Reactors (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a water level detector for extending service life of a probe used for detecting water level in a reactor container.SOLUTION: The water level detector measures the position of liquid face of a liquid in a reactor container. The water level detector includes: a probe which is disposed in the reactor container; a power supply that supplies a DC current to the probe; a current measurement circuit that measures the DC current flowing on the probe; and a current limit circuit that limits the magnitude of the DC current supplied to the probe based on the concentration electrolyte of the liquid.

Description

本発明は、原子炉格納容器内の水位を検出する水位検出装置に関する。   The present invention relates to a water level detection device for detecting a water level in a reactor containment vessel.

原子炉格納容器内の水位検出装置は圧力バウンダリの拡大及び設備物量の増大を最小限に抑えるとともに、機械的な可動部をなくして故障頻度の低減及び保守性の向上を図ることが要求される。例えば、特許文献１には、水位検出装置に電極式レベルスイッチ、同心円状の金属プローブ間の静電容量を測定する静電容量式レベルスイッチや超音波発振器で発振された超音波の反射時間の差から水位の有無を測定する超音波式レベルスイッチ等の各種の水位検出装置を設けることが記載されている。   The water level detection device in the reactor containment vessel is required to minimize the expansion of the pressure boundary and the amount of equipment, and to reduce the failure frequency and improve the maintainability by eliminating the mechanical moving parts. . For example, Patent Document 1 discloses a reflection level of an ultrasonic wave oscillated by an ultrasonic wave oscillator or an electrostatic level switch that measures an electrostatic capacity between an electrode type level switch and a concentric metal probe in a water level detection device. It is described that various water level detection devices such as an ultrasonic level switch for measuring the presence or absence of a water level from the difference are provided.

特開平１１-１１８９７６号公報Japanese Patent Laid-Open No. 11-118976

原子炉格納容器内の水位検出においては、簡易な構成で長寿命であること、幅広い水質に対応できることが必要とされる。高感度での水位検出のためには、直流電流であることが好ましい。このように直流電流を使用し、高温、高湿度かつ高放射線の環境下で、長寿命であるためには、プローブの溶出を防ぐこと並びにプローブの構成材料の耐久性を向上させることが必要である。水位検出装置に直流電流を用いることと、プローブの溶出を防ぐことは、トレードオフの関係になっており、双方を満たすことが求められている。   In the detection of the water level in the reactor containment vessel, it is necessary to have a simple configuration with a long life and to cope with a wide range of water quality. In order to detect the water level with high sensitivity, a direct current is preferable. In order to use a direct current in this way and have a long life under high temperature, high humidity and high radiation, it is necessary to prevent elution of the probe and to improve the durability of the constituent materials of the probe. is there. Using a direct current for the water level detection device and preventing the elution of the probe are in a trade-off relationship, and both are required to be satisfied.

原子炉格納容器内の水位検出装置は、発電設備の非常時に原子炉格納容器内に注入される発電設備が保安用に保有する水の注入量を検出するため、水位を電流値の変化として高感度で検出できることが要求される。また、測定地点から離隔距離が大きいため、ノイズの影響を低減することも要求される。これらの要求を満たすため、水位の検出には直流電流が用いられる。その結果、例えば、発電設備の非常時において、海水等の電解質を多く含む水を注入する場合、プローブが電気分解の作用により溶出する可能性がある。   The water level detection device in the reactor containment vessel detects the amount of water that the power generation facility that is injected into the reactor containment vessel in the event of an emergency in the power generation facility. It must be detectable with sensitivity. Further, since the separation distance from the measurement point is large, it is also required to reduce the influence of noise. In order to satisfy these requirements, a direct current is used to detect the water level. As a result, for example, when water containing a large amount of electrolyte such as seawater is injected in an emergency of a power generation facility, the probe may be eluted by the action of electrolysis.

本発明は、原子炉格納容器内の水位検出用プローブを長寿命化するための水位検出装置を提供することを目的とする。   An object of this invention is to provide the water level detection apparatus for extending the lifetime of the water level detection probe in a nuclear reactor containment vessel.

本発明は、原子炉格納容器内の液体の液面位置を計測するにあたって、前記原子炉格納容器内に設けられる水位検出用プローブと、前記水位検出用プローブに直流電流を供給する電源と、前記水位検出用プローブを流れる前記直流電流を計測する電流測定回路と、前記液体の電解質の濃度に基づいて前記水位検出用プローブに供給される前記直流電流の大きさを制限する電流制限回路と、を含む水位検出装置である。   The present invention provides a water level detection probe provided in the nuclear reactor containment vessel, a power source for supplying a direct current to the water level detection probe, and the liquid level position of the liquid in the nuclear reactor containment vessel, A current measurement circuit for measuring the DC current flowing through the water level detection probe; and a current limiting circuit for limiting the magnitude of the DC current supplied to the water level detection probe based on the concentration of the electrolyte in the liquid. It is a water level detection device including.

この水位検出装置は、水位検出用プローブに流れる電流を制限する電流制限回路を用いるので、水位検出用プローブに過大な電流が流れることを抑制できる。その結果、原子炉格納容器内で水位を検出するために用いられる水位検出用プローブの溶出を制限することになり、長寿命化が可能になる。   Since this water level detection device uses a current limiting circuit that limits the current flowing through the water level detection probe, it is possible to suppress an excessive current from flowing through the water level detection probe. As a result, the elution of the water level detection probe used for detecting the water level in the reactor containment vessel is limited, and the life can be extended.

前記電源、前記電流測定回路及び前記電流制限回路は、前記原子炉格納容器の外に設置されることが好ましい。このようにすれば、電流測定回路及び電流制限回路のメンテナンスが容易になると共に、発電設備の非常時においても原子炉格納容器内の環境悪化の影響を受けにくいといった利点がある。   The power source, the current measurement circuit, and the current limiting circuit are preferably installed outside the reactor containment vessel. In this way, there are advantages that the maintenance of the current measuring circuit and the current limiting circuit is facilitated and that it is less susceptible to environmental deterioration in the reactor containment vessel even in the event of an emergency power generation facility.

前記電流制限回路は、前記水位検出用プローブに一定以上の直流電流が流れた場合、水位検出用プローブ両端に印加される電圧が調節される回路であることが好ましい。電気抵抗を用いることで、電流制限回路を比較的容易に構成することができる。   The current limiting circuit is preferably a circuit that adjusts a voltage applied to both ends of the water level detection probe when a DC current of a certain level or more flows through the water level detection probe. By using the electrical resistance, the current limiting circuit can be configured relatively easily.

前記水位検出用プローブの電極は、第四族元素及び第五族元素のうち少なくとも一つ以上を含むことが好ましい。このようにすることで、電極の耐久性を向上させることができる。   The electrode of the water level detection probe preferably includes at least one of a Group 4 element and a Group 5 element. By doing in this way, durability of an electrode can be improved.

前記水位検出用プローブに利用される絶縁材には、一部がセラミックスであることが好ましい。このようにすることで、水位検出用プローブの耐久性を向上させることができる。   It is preferable that a part of the insulating material used for the water level detection probe is ceramic. By doing in this way, durability of the probe for water level detection can be improved.

前記水位検出用プローブは、前記セラミックスと前記電極とが接合されていることが好ましい。   In the water level detection probe, the ceramic and the electrode are preferably joined.

本発明は、高温、高湿度かつ高放射線の環境下で使用される原子炉格納容器内の水位検出用プローブを長寿命化するための水位検出装置を提供することができる。   The present invention can provide a water level detection device for extending the life of a water level detection probe in a reactor containment vessel used in an environment of high temperature, high humidity and high radiation.

図１は、原子炉格納容器内の原子炉容器とその周辺機器を含む空間を示す図である。FIG. 1 is a view showing a space including a nuclear reactor vessel and its peripheral devices in the nuclear reactor containment vessel. 図２ａは、水位検出装置を有する電流制限回路の一例を示す図である。FIG. 2a is a diagram illustrating an example of a current limiting circuit having a water level detection device. 図２ｂは、水位検出装置を有する他の電流制限回路を示す図である。FIG. 2b shows another current limiting circuit with a water level detection device. 図２ｃは、水位検出装置が有する他の電流制限回路を示す図である。FIG. 2c is a diagram illustrating another current limiting circuit included in the water level detection device. 図２ｄは、水位検出装置が有する他の電流制限回路の例を示す図である。FIG. 2d is a diagram illustrating an example of another current limiting circuit included in the water level detection device. 図３ａは、プローブを示す図である。FIG. 3a shows a probe. 図３ｂは、プローブの分解図である。FIG. 3b is an exploded view of the probe. 図３ｃは、プローブに含まれる電極の一例を示す図である。FIG. 3c is a diagram illustrating an example of electrodes included in the probe.

図１は、原子炉格納容器内の原子炉容器２を含む空間１０とその周辺機器とを示す図である。原子炉格納容器１９の内部は、密閉されている空間であり、外部より注水することで格納容器内の水位が上昇する。   FIG. 1 is a diagram showing a space 10 including a reactor vessel 2 in a reactor containment vessel and peripheral devices thereof. The inside of the reactor containment vessel 19 is a sealed space, and the water level in the containment vessel rises by pouring water from the outside.

原子炉格納容器内の空間１０には、発電装置の非常時に、注水される水位の上昇を監視するために、格納容器内に水位の検知箇所が設定されている。原子炉格納容器内の空間１０内の水位を計測するために、水位検出装置１４の一対の水位検出用プローブ（以下、適宜プローブと称する）１５が設置されている。プローブ１５を上限水位１２の位置に設けることにより、原子炉格納容器１９内に設置される重要機器が水没しないよう監視することができる。また、原子炉容器２の底面よりも低い位置の空間にプローブ１５を設け、下部水位１３として水位の検知箇所を追加することで、直接的に溶融した燃料の冠水状態を監視するための手段を提供することも出来る。一対のプローブ１５は、水位の上昇を監視する目的から、複数の場所を測定できるよう設置してもよい。   In the space 10 in the reactor containment vessel, a water level detection point is set in the containment vessel in order to monitor the rise of the water level to be poured in the event of an emergency of the power generation device. In order to measure the water level in the space 10 in the reactor containment vessel, a pair of water level detection probes (hereinafter referred to as probes as appropriate) 15 of the water level detection device 14 is installed. By providing the probe 15 at the position of the upper limit water level 12, it is possible to monitor the important equipment installed in the reactor containment vessel 19 so as not to be submerged. In addition, by providing a probe 15 in a space lower than the bottom surface of the reactor vessel 2 and adding a water level detection point as the lower water level 13, means for directly monitoring the flooded state of the molten fuel is provided. It can also be provided. The pair of probes 15 may be installed so that a plurality of locations can be measured for the purpose of monitoring the rise in water level.

原子炉格納容器１９の水は、原子炉格納容器１９の下層フロアから格納容器再循環サンプへ流入する経路が確保されている。格納容器再循環サンプ水位計１１又は格納容器内への注水経路に設置される流量計等の積算値を求めることで、原子炉格納容器内の空間１０に注水した量を測定し、間接的に水位を推定することが可能であるため、これらを用いて原子炉格納容器１９内の水位を把握することが可能である。さらに、発電設備の非常時においても、原子炉格納容器内の空間１０の水位を直接的に監視し、格納容器再循環サンプ水位計等既存の水位計の計測範囲を超える範囲に対しても水位を監視可能なように、水位検出装置１４を設ける。   A path for the water in the reactor containment vessel 19 to flow from the lower floor of the reactor containment vessel 19 to the containment vessel recirculation sump is secured. The amount of water injected into the space 10 in the reactor containment vessel is measured by obtaining the integrated value of the containment vessel recirculation sump water level meter 11 or a flow meter installed in the water injection path into the containment vessel, and indirectly Since it is possible to estimate the water level, it is possible to grasp the water level in the reactor containment vessel 19 using these. Furthermore, even in the event of an emergency in the power generation facility, the water level in the space 10 in the reactor containment vessel is directly monitored, and the water level is also exceeded for ranges that exceed the measurement range of existing water level meters such as the containment vessel recirculation sump water level meter. The water level detection device 14 is provided so that it can be monitored.

水位検出装置１４は、一対のプローブ１５、水位測定回路１６、電流制限回路１７及び直流電源１８を含む。水位検出装置１４は、圧力バウンダリの拡大及び設備物量の増大を最小限に抑えるため、プローブ１５が原子炉格納容器１９内に設けられ、水位測定回路１６、電流制限回路１７及び直流電源１８が中央操作室２０に設けられる。水位測定回路１６は、水位状態を表示する機器２１に接続されてもよいし、記録装置に接続されてもよい。   The water level detection device 14 includes a pair of probes 15, a water level measurement circuit 16, a current limiting circuit 17, and a DC power source 18. In the water level detection device 14, in order to minimize the expansion of the pressure boundary and the increase in the amount of equipment, the probe 15 is provided in the reactor containment vessel 19, and the water level measurement circuit 16, the current limiting circuit 17, and the DC power source 18 are provided in the center. It is provided in the operation room 20. The water level measurement circuit 16 may be connected to a device 21 that displays a water level state or may be connected to a recording device.

電流制限回路１７には、例えばＩＧＢＴ（Insulate Gate Bipolar Transistor）、ＭＯＳＦＥＴ（Metal Oxide Semiconductor Field Effect Transistor）又はバイポーラトランジスタ等のトランジスタを用いて実現されてもよいし、トランジスタ等と電気的に等価となる回路により実現されてもよい。   The current limiting circuit 17 may be realized by using a transistor such as an IGBT (Insulate Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), or a bipolar transistor, or is electrically equivalent to a transistor or the like. It may be realized by a circuit.

図２ａは、水位検出装置を有する電流制限回路１７の一例を示す図である。図２ｂは、水位検出装置を有する他の電流制限回路１７ａを示す図である。図２ｃは、水位検出装置が有する他の電流制限回路１７ｂを示す図である。図２ｄは、水位検出装置が有する他の電流制限回路１７ｃの例を示す図である。   FIG. 2a is a diagram illustrating an example of a current limiting circuit 17 having a water level detection device. FIG. 2b is a diagram showing another current limiting circuit 17a having a water level detection device. FIG. 2c is a diagram illustrating another current limiting circuit 17b included in the water level detection device. FIG. 2d is a diagram illustrating an example of another current limiting circuit 17c included in the water level detection device.

図２ａに示す電流制限回路１７は、水位測定回路１６と直流電源１８との間に電気抵抗３１を設け、一定値以上の電流がプローブ１５に流れないようにした回路である。電気抵抗３１の電気抵抗値をＲ１、プローブ１５、１５の間に存在する可能性のある液体のうち、最も電気抵抗値の小さい液体の電気抵抗値をＲ２とする。一対のプローブ１５、１５に前述した最も電気抵抗値の小さい液体が存在する場合、直流電源１８、電気抵抗３１、水位測定回路１６及びプローブ１５、最も電気抵抗値の小さい液体及びプローブ１５で閉回路が形成される。直流電源１８の端子間電圧をＶとすると、電流制限回路１７を流れる電流Ｉは、式（１）で求めることができる。
Ｉ＝Ｖ／（Ｒ１＋Ｒ２）・・（１） The current limiting circuit 17 shown in FIG. 2 a is a circuit in which an electric resistance 31 is provided between the water level measurement circuit 16 and the DC power supply 18 so that a current exceeding a certain value does not flow to the probe 15. The electric resistance value of the electric resistance 31 is R1, and among the liquids that may exist between the probes 15 and 15, the electric resistance value of the liquid having the smallest electric resistance value is R2. When the liquid having the smallest electric resistance value is present in the pair of probes 15 and 15, the DC power source 18, the electric resistance 31, the water level measurement circuit 16 and the probe 15, the liquid having the smallest electric resistance value and the probe 15 are closed circuit Is formed. Assuming that the voltage between the terminals of the DC power supply 18 is V, the current I flowing through the current limiting circuit 17 can be obtained by Expression (1).
I = V / (R1 + R2) (1)

電流制限回路１７を流れる電流ＩをＩ＿ｌｉｍ以下に制限したい場合、式（１）を用いて、Ｒ１は式（２）に示すようになる。一対のプローブ１５、１５の間に存在する可能性のある液体のうち、最も電気抵抗値の小さい液体を想定し、かつプローブ１５、１５に流れる電流の上限値Ｉ＿ｌｉｍを定めることで、式（２）から電気抵抗３１の電気抵抗値Ｒ１を求めることができる。このようにして求めた電気抵抗値Ｒ１を有する電気抵抗３１を用いることにより、電流制限回路１７は、プローブ１５、１５を流れる電流Ｉを、上限値Ｉ＿ｌｉｍ以下に制限することができる。
Ｒ１＞Ｖ／Ｉｌｉｍ−Ｒ２・・（２） When it is desired to limit the current I flowing through the current limiting circuit 17 to I_lim or less, R1 is expressed by the equation (2) using the equation (1). By assuming the liquid having the smallest electrical resistance value among the liquids that may exist between the pair of probes 15 and 15 and determining the upper limit value I_lim of the current flowing through the probes 15 and 15, the equation (2 ), The electric resistance value R1 of the electric resistance 31 can be obtained. By using the electrical resistance 31 having the electrical resistance value R1 thus obtained, the current limiting circuit 17 can limit the current I flowing through the probes 15 and 15 to the upper limit value I_lim or less.
R1> V / Ilim-R2 (2)

図２ｂに示す電流制限回路１７ａは、水位測定回路１６と直流電源１８との間に可変電気抵抗３３を設けた回路である。この電流制限回路１７ａを用いる場合、例えば作業者３２が、水位測定回路１６の電流値を管理室で読み取り、電流値が上限値Ｉ＿ｌｉｍを超えていれば、可変電気抵抗３３の電気抵抗値を変更する。このようにすることで、一対のプローブ１５に流れる電流の量が一定となるように、かつ上限値Ｉ＿ｌｉｍを超えないようにする。また、可変電気抵抗３３は、水位測定回路１６からの信号により上限値Ｉ＿ｌｉｍを超えないよう自動で調整されるようにしてもよい。   The current limiting circuit 17a shown in FIG. 2b is a circuit in which a variable electrical resistance 33 is provided between the water level measurement circuit 16 and the DC power source 18. When this current limiting circuit 17a is used, for example, the operator 32 reads the current value of the water level measuring circuit 16 in the management room, and changes the electric resistance value of the variable electric resistance 33 if the current value exceeds the upper limit value I_lim. To do. By doing so, the amount of current flowing through the pair of probes 15 is kept constant and does not exceed the upper limit value I_lim. The variable electrical resistance 33 may be automatically adjusted so as not to exceed the upper limit value I_lim by a signal from the water level measurement circuit 16.

この場合、例えば、制御装置３０が、水位測定回路１６によって検出された電流値Ｉｃと、電流制限回路１７ａを流れる電流の目標電流値Ｉｐとの差分が０になるように、可変電気抵抗３３をフィードバック制御することができる。目標電流値Ｉｐは、上限値Ｉ＿ｌｉｍ以下に設定される。このようにすることで、電流制限回路１７ａは、プローブ１５を流れる電流Ｉを、上限値Ｉ＿ｌｉｍ以下に制限することができる。   In this case, for example, the control device 30 sets the variable electrical resistance 33 so that the difference between the current value Ic detected by the water level measurement circuit 16 and the target current value Ip of the current flowing through the current limiting circuit 17a becomes zero. Feedback control can be performed. The target current value Ip is set to the upper limit value I_lim or less. By doing so, the current limiting circuit 17a can limit the current I flowing through the probe 15 to the upper limit value I_lim or less.

図２ｃに示す電流制限回路１７ｂは、水位測定回路１６と直流電源１８との間にｎｐｎ型トランジスタ３６を設け、ｎｐｎ型トランジスタ３６のベースに可変電源３４と電気抵抗３５を、ｎｐｎ型トランジスタ３６のコレクタ側に直流電源１８を設けた回路である。図２ｂに示す電流制限回路１７ａの可変電気抵抗３３を用いる方法での制御は容易であるが、可変電気抵抗３３で電力が消費されるので、直流電源の消耗が大きい。図２ｃに示す電流制限回路１７ｂは、直流電源１８とは異なる可変電源３４を制御することで、直流電源１８の消耗を抑制することができる。可変電源３４は、水位測定回路１６で計測された電流値をフィードバックすることで、電気抵抗３５を介してｎｐｎ型トランジスタ３６がプローブ１５に流す電流Ｉを調整する。調整のための操作は自動で行われてもよいし、作業者が手動で行ってもよい。   The current limiting circuit 17b shown in FIG. 2c includes an npn-type transistor 36 between the water level measurement circuit 16 and the DC power source 18, and a variable power source 34 and an electric resistor 35 at the base of the npn-type transistor 36. In this circuit, a DC power source 18 is provided on the collector side. Although control by the method using the variable electric resistance 33 of the current limiting circuit 17a shown in FIG. 2b is easy, since power is consumed by the variable electric resistance 33, the consumption of the DC power supply is large. The current limiting circuit 17b shown in FIG. 2c can suppress consumption of the DC power supply 18 by controlling the variable power supply 34 different from the DC power supply 18. The variable power supply 34 feeds back the current value measured by the water level measurement circuit 16, thereby adjusting the current I that the npn transistor 36 flows to the probe 15 through the electric resistance 35. The operation for adjustment may be performed automatically or manually by an operator.

図２ｄに示す電流制限回路１７ｃは、水位測定回路１６と直流電源１８との間にｐｎｐ型トランジスタ３９を設け、ダイオード３８をｐｎｐ型トランジスタ３９のベースに、電気抵抗３７をｐｎｐ型トランジスタ３９のエミッタに接続した回路である。   The current limiting circuit 17c shown in FIG. 2d includes a pnp transistor 39 between the water level measuring circuit 16 and the DC power supply 18, a diode 38 as a base of the pnp transistor 39, and an electric resistor 37 as an emitter of the pnp transistor 39. It is a circuit connected to.

ダイオード３８の順方向における電圧降下の最大値は、ダイオード３８を構成する材料の物性により決まっていることから、電気抵抗３７に流れる電圧の最大値はダイオード３８の順方向電圧降下となる。一対のプローブ１５、１５間の電気抵抗が一定以下になった場合でも、電流Ｉは式（３）で求める値を超えることはない。Ｉ＿ｌｉｍはプローブ１５に流れる電流の上限値、Ｖｄはダイオード３８の順方向電圧降下、Ｒは電気抵抗３７の電気抵抗値である。このように、電流制限回路１７ｃは、電気抵抗３７の電気抵抗値Ｒを適切な値とすることにより、プローブ１５を流れる電流Ｉを、上限値Ｉ＿ｌｉｍ以下に制限することができる。
Ｉ＿ｌｉｍ＝Ｖｄ／Ｒ・・（３） Since the maximum value of the voltage drop in the forward direction of the diode 38 is determined by the physical properties of the material constituting the diode 38, the maximum value of the voltage flowing through the electric resistance 37 is the forward voltage drop of the diode 38. Even when the electrical resistance between the pair of probes 15 and 15 becomes below a certain level, the current I does not exceed the value obtained by the equation (3). I_lim is an upper limit value of the current flowing through the probe 15, Vd is a forward voltage drop of the diode 38, and R is an electric resistance value of the electric resistor 37. Thus, the current limiting circuit 17c can limit the current I flowing through the probe 15 to the upper limit value I_lim or less by setting the electric resistance value R of the electric resistance 37 to an appropriate value.
I_lim = Vd / R (3)

図３ａは、プローブ１５を示す図である。図３ｂは、プローブ１５の分解図である。プローブ１５は、電極２８と、キャップ２９、スリーブ２４Ａ、アダプタ２４Ｂと環状部材２３と、チタンを含んでいる絶縁機能を有するパーツ２２とを含む。電極２８、キャップ２９、スリーブ２４Ａ、と環状部材２３は、本実施形態においてはチタン又はチタン合金であるが、第四族元素及び第五族元素のうち少なくとも一つ以上を含んでいればよい。環状部材２３も、本実施形態においてはチタン又はチタン合金であるが、第四族元素及び第五族元素のうち少なくとも一つ以上を含んでいればよい。ＭＩ（Mineral Insulator）ケーブル被覆２５、アダプタ２４Ｂは、例えば鉄を主成分とする合金である。ＭＩ絶縁体２６は、例えば酸化マグネシウムである。   FIG. 3 a shows the probe 15. FIG. 3 b is an exploded view of the probe 15. The probe 15 includes an electrode 28, a cap 29, a sleeve 24A, an adapter 24B, an annular member 23, and a part 22 having an insulating function containing titanium. The electrode 28, the cap 29, the sleeve 24 </ b> A, and the annular member 23 are titanium or a titanium alloy in the present embodiment, but may include at least one of the Group 4 element and the Group 5 element. Although the annular member 23 is also titanium or a titanium alloy in this embodiment, it should just contain at least 1 or more among a group 4 element and a group 5 element. The MI (Mineral Insulator) cable sheath 25 and the adapter 24B are, for example, an alloy containing iron as a main component. The MI insulator 26 is, for example, magnesium oxide.

プローブ１５は、ＭＩケーブルの末端に接続される。電極２８は、パーツ２２を貫通して、アダプタ２４Ｂ内でと強固に接着される。電極２８のＭＩケーブル側端面はＭＩケーブルの芯材２７と溶接又はろう付けにより接合される。また、電極２８はキャップ２９と溶接又はろう付けにより接合される。パーツ２２は、絶縁及び耐水性機能を有する材料から成り、環状部材２３とろう付けにより強固に接着される。パーツ２２はセラミックス製であるため、キャップ２９およびスリーブ２４Ａと接触して設けられ、環状部材２３と溶接又はろう付けすることによりこれらの部品と接着する。芯材２７と電極２８は、ケーブル被覆２５、アダプタ２４Ｂ、スリーブ２４Ａ、上側の環状部材２３と接触しないよう、セラミックの絶縁体２６を内部に充填して固定される。   The probe 15 is connected to the end of the MI cable. The electrode 28 penetrates the part 22 and is firmly bonded in the adapter 24B. The MI cable side end surface of the electrode 28 is joined to the core member 27 of the MI cable by welding or brazing. The electrode 28 is joined to the cap 29 by welding or brazing. The part 22 is made of a material having an insulating and water-resistant function, and is firmly bonded to the annular member 23 by brazing. Since the part 22 is made of ceramics, the part 22 is provided in contact with the cap 29 and the sleeve 24 </ b> A, and adheres to these parts by welding or brazing to the annular member 23. The core member 27 and the electrode 28 are fixed by being filled with a ceramic insulator 26 so as not to come into contact with the cable sheath 25, the adapter 24B, the sleeve 24A, and the upper annular member 23.

プローブ１５は、例えばチタンと耐水性を有するセラミックス（アルミナ）で構成される。その他、コバールと耐水性を有するセラミックスとの組み合わせでもよい。なお、プローブ１５に使用される非導通材には、設置環境における耐熱性、耐放射線性に応じてセラミックス（アルミナや酸化マグネシウム等）以外にもプラスチック等の樹脂材料（例えば、ポリイミドや芳香族エーテルケトン、エポキシ等）を用いてもよい。   The probe 15 is made of, for example, titanium and water-resistant ceramic (alumina). In addition, a combination of Kovar and ceramics having water resistance may be used. The non-conductive material used for the probe 15 is not only ceramics (alumina, magnesium oxide, etc.) but also a resin material such as plastic (for example, polyimide or aromatic ether) according to the heat resistance and radiation resistance in the installation environment. Ketone, epoxy, etc.) may be used.

本実施形態は、電流制限回路１７、１７ａ、１７ｂ、１７ｃを用いてプローブ１５を流れる電流を制限する。その結果、プローブ１５に過大な電流が流れることを抑制できるので、電蝕によるプローブの溶出を抑制でき、原子炉格納容器１９内のプローブ１５を長寿命化することができる。   In the present embodiment, the current flowing through the probe 15 is limited using the current limiting circuits 17, 17a, 17b, and 17c. As a result, since an excessive current can be suppressed from flowing through the probe 15, elution of the probe due to electrolytic corrosion can be suppressed, and the life of the probe 15 in the reactor containment vessel 19 can be extended.

図３ｃは、プローブ１５に含まれる電極２８の一例を示す図である。電極２８は、組み立て時に対向する電極板２８ｂを含む。電極板２８ｂの形状は円形、楕円形、長方形、正方形、棒状などであり、対向する電極板の面積は等しいことが好ましいが、異なっても良い。互いに対抗する電極板２８ｂの存在により、プローブ１５の水との接触面積を拡大し、センサーとしての感度を向上させることができる。   FIG. 3 c is a diagram illustrating an example of the electrode 28 included in the probe 15. The electrode 28 includes an electrode plate 28b that faces when assembled. The electrode plate 28b has a circular shape, an elliptical shape, a rectangular shape, a square shape, a rod shape, and the like. The areas of the opposing electrode plates are preferably equal, but may be different. Due to the presence of the electrode plates 28b facing each other, the contact area of the probe 15 with water can be increased, and the sensitivity as a sensor can be improved.

以上、実施形態に記載した内容により本発明が限定されるものではない。また、実施形態の構成要素には、当業者が容易に想定できるもの、実質的に同一のもの、均等の範囲のものが含まれる。さらに、実施形態に記載した構成要素は適宜組み合わせることが可能である。また、実施形態の要旨を逸脱しない範囲で構成要素の種々の省略、置換又は変更を行うことができる。   As described above, the present invention is not limited by the contents described in the embodiments. The constituent elements of the embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are equivalent. Furthermore, the components described in the embodiments can be combined as appropriate. In addition, various omissions, substitutions, or changes of the components can be made without departing from the scope of the embodiment.

２ 原子炉容器
１０ 原子炉格納容器内の空間
１１ 格納容器再循環サンプ水位計
１２ 上限水位
１３ 格納容器内水位
１４ 水位検出装置
１５ 水位検出用プローブ（プローブ）
１６ 水位測定回路
１７、１７ａ、１７ｂ、１７ｃ 電流制限回路
１８ 直流電源
１９ 原子炉格納容器
２０ 中央操作室
２１ 機器
２２ パーツ
２３ 環状部材
２４Ａ スリーブ
２４Ｂ アダプタ
２５ ケーブル被覆
２６ 絶縁体
２７ 芯材
２８ 電極
２８ｂ 電極板
２９ キャップ
３０ 制御装置
３１ 電気抵抗
３３ 可変電気抵抗
３４ 可変電源
３５ 電気抵抗
３６ ｎｐｎ型トランジスタ
３７ 電気抵抗
３８ ダイオード
３９ ｐｎｐ型トランジスタ 2 Reactor vessel 10 Space in reactor containment vessel 11 Containment vessel recirculation sump water level meter 12 Upper water level 13 Water level in containment vessel 14 Water level detection device 15 Water level detection probe (probe)
16 Water level measurement circuit 17, 17a, 17b, 17c Current limiting circuit 18 DC power source 19 Reactor containment vessel 20 Central operation room 21 Equipment 22 Parts 23 Annular member 24A Sleeve 24B Adapter 25 Cable coating 26 Insulator 27 Core material 28 Electrode 28b Electrode Plate 29 Cap 30 Controller 31 Electrical resistance 33 Variable electrical resistance 34 Variable power supply 35 Electrical resistance 36 npn transistor 37 Electrical resistance 38 Diode 39 pnp transistor

Claims (6)

原子炉格納容器内の液体の液面位置を計測するにあたって、
前記原子炉格納容器内に設けられるプローブと、
水位検出に用いられる前記プローブに直流電流を供給する電源と、
前記プローブを流れる前記直流電流を計測する電流測定回路と、
前記液体の電解質の濃度に基づいて前記プローブに供給される前記直流電流の大きさを制限する電流制限回路と、
を含む水位検出装置。 In measuring the liquid level in the reactor containment vessel,
A probe provided in the reactor containment vessel;
A power supply for supplying a direct current to the probe used for water level detection;
A current measuring circuit for measuring the DC current flowing through the probe;
A current limiting circuit that limits the magnitude of the direct current supplied to the probe based on the concentration of the liquid electrolyte;
Including a water level detection device. 前記電源、前記電流測定回路及び前記電流制限回路は、前記原子炉格納容器の外に設置される、請求項１に記載の水位検出装置。   The water level detection device according to claim 1, wherein the power source, the current measurement circuit, and the current limiting circuit are installed outside the reactor containment vessel. 前記電流制限回路は、前記プローブに一定以上の前記直流電流が流れた場合、電気抵抗が変更される回路である、請求項１又は請求項２に記載の水位検出装置。   The water level detection device according to claim 1, wherein the current limiting circuit is a circuit in which an electrical resistance is changed when the DC current of a certain level or more flows through the probe. 前記プローブに含まれる電極は、第四族元素及び第五族元素のうち少なくとも一つ以上を含む請求項１から請求項３のいずれか１項に記載の水位検出装置。   The water level detection device according to any one of claims 1 to 3, wherein the electrode included in the probe includes at least one of a Group 4 element and a Group 5 element. 前記プローブは、一部がセラミックスである請求項１から請求項４のいずれか１項に記載の水位検出装置。   The water level detection device according to claim 1, wherein a part of the probe is ceramic. 前記プローブは、前記セラミックスと前記電極とが接合されている、請求項１から請求項５のいずれか１項に記載の水位検出装置。   The water level detection device according to any one of claims 1 to 5, wherein the probe is bonded to the ceramic and the electrode.
JP2014085706A 2014-04-17 2014-04-17 Water level detection device Active JP6479334B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2014085706A JP6479334B2 (en) 2014-04-17 2014-04-17 Water level detection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2014085706A JP6479334B2 (en) 2014-04-17 2014-04-17 Water level detection device

Publications (2)

Publication Number Publication Date
JP2015206615A true JP2015206615A (en) 2015-11-19
JP6479334B2 JP6479334B2 (en) 2019-03-06

Family

ID=54603518

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2014085706A Active JP6479334B2 (en) 2014-04-17 2014-04-17 Water level detection device

Country Status (1)

Country Link
JP (1) JP6479334B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017146343A (en) * 2016-02-15 2017-08-24 アルパイン株式会社 On-vehicle display device

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4914157U (en) * 1972-05-09 1974-02-06
JPS52141361U (en) * 1976-04-19 1977-10-26
JPS5328750U (en) * 1976-08-19 1978-03-11
JPS5514505U (en) * 1978-07-14 1980-01-30
JPS59168322A (en) * 1983-03-14 1984-09-22 Toyota Central Res & Dev Lab Inc Method and device for measuring lubricating oil
JPS60111116A (en) * 1983-11-18 1985-06-17 Ngk Insulators Ltd Water level detecting element
JP2001324590A (en) * 2000-05-17 2001-11-22 Toshiba Eng Co Ltd System for measuring water level of nuclear reactor
JP2002013963A (en) * 2000-06-28 2002-01-18 Koichi Yamai Electrode type liquid level indicator
JP2003035586A (en) * 2001-07-23 2003-02-07 Konami Sports Life Corp Water gauge and method of sterilizing water gauge
JP2005241475A (en) * 2004-02-26 2005-09-08 Nissei Electric Co Ltd Liquid level sensor
US20070115308A1 (en) * 2005-11-24 2007-05-24 Kabushiki Kaisha Toshiba Liquid quantity sensing device
JP2013205060A (en) * 2012-03-27 2013-10-07 Mitsubishi Heavy Ind Ltd Water level gauge and nuclear facility
JP2014215179A (en) * 2013-04-25 2014-11-17 株式会社東芝 Water level and temperature measuring device and water level temperature measurement system

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4914157U (en) * 1972-05-09 1974-02-06
JPS52141361U (en) * 1976-04-19 1977-10-26
JPS5328750U (en) * 1976-08-19 1978-03-11
JPS5514505U (en) * 1978-07-14 1980-01-30
JPS59168322A (en) * 1983-03-14 1984-09-22 Toyota Central Res & Dev Lab Inc Method and device for measuring lubricating oil
JPS60111116A (en) * 1983-11-18 1985-06-17 Ngk Insulators Ltd Water level detecting element
JP2001324590A (en) * 2000-05-17 2001-11-22 Toshiba Eng Co Ltd System for measuring water level of nuclear reactor
JP2002013963A (en) * 2000-06-28 2002-01-18 Koichi Yamai Electrode type liquid level indicator
JP2003035586A (en) * 2001-07-23 2003-02-07 Konami Sports Life Corp Water gauge and method of sterilizing water gauge
JP2005241475A (en) * 2004-02-26 2005-09-08 Nissei Electric Co Ltd Liquid level sensor
US20070115308A1 (en) * 2005-11-24 2007-05-24 Kabushiki Kaisha Toshiba Liquid quantity sensing device
JP2013205060A (en) * 2012-03-27 2013-10-07 Mitsubishi Heavy Ind Ltd Water level gauge and nuclear facility
JP2014215179A (en) * 2013-04-25 2014-11-17 株式会社東芝 Water level and temperature measuring device and water level temperature measurement system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017146343A (en) * 2016-02-15 2017-08-24 アルパイン株式会社 On-vehicle display device

Also Published As

Publication number Publication date
JP6479334B2 (en) 2019-03-06

Similar Documents

Publication Publication Date Title
KR101884619B1 (en) Heat radiation-resistant ntc temperature sensors and applications thereof
US10422680B2 (en) Method for monitoring at least one media-specific property of a medium
US9772369B2 (en) Precision measurement of voltage drop across a semiconductor switching element
CN108450018B (en) Method and device for detecting aging of a power electronic device comprising a semiconductor component, and power electronic system
US9372012B2 (en) Determining heating element and water heater status based on galvanic current
KR20060052602A (en) Resistance heater
CN101159225A (en) Method for measuring liquid film thickness of electrically-conductive backing plate
KR20120113306A (en) Detecting device for temperature of terminal
JP2011145294A (en) Liquid level measuring probe
JP6479334B2 (en) Water level detection device
JP6258064B2 (en) Semiconductor test equipment
JP2016109474A (en) Noncontact voltage sensor and electric power measurement device
US9091583B2 (en) Fluid level sensor system and method
JP2018031671A (en) Temperature detector
US20140376592A1 (en) Device for representing and displaying the coil temperature of an electrical power transformer and limitation circuit suitable therefor
JP2016205874A (en) Resin degradation measurement sensor and degradation measurement system
JP5274515B2 (en) Moisture concentration detector
JP4532357B2 (en) Concentration measuring device
CA2709206C (en) Assembly for measurement of a metal level in a reduction cell
JP2014215179A (en) Water level and temperature measuring device and water level temperature measurement system
KR101113018B1 (en) Electric heater, temperature control module, and method for controlling the temperature of the electric heater
US9551602B2 (en) Electromagnetic flow meter and magnetic excitation control method
US9671265B2 (en) Thermal dispersion mass flow rate, material interface, and liquid level sensing transducer
CN108827422B (en) liquid metal liquid level continuous measuring device and liquid level measuring method thereof
CN207717188U (en) A kind of nuclear heat island changing resistor type level detection device assembly

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20170301

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20171124

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20171205

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20180130

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20180626

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20180801

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20190108

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20190206

R150 Certificate of patent or registration of utility model

Ref document number: 6479334

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150