JP3693946B2 - Leak position detection line and leak detection system using the same - Google Patents

Description

導電線３ａの単位長さあたりの導体抵抗Ｒ₁ が抵抗線２ａの単位長さあたりの導体抵抗Ｒ₀ に比べて無視し得るほどに小さいと次の近似式が成り立つ。
Ｖ_Y ／Ｖ_X ≒Ｙ／Ｘ （５）
式（４）から、
Ｙ＝Ｌ−Ｘ
であるから、これを式（５）代入すると、
Ｖ_Y ／Ｖ_X ≒（Ｌ／Ｘ）−１
Ｘ＝Ｌ×〔Ｖ_X ／（Ｖ_X ＋Ｖ_Y ）〕 （６）
同様にして、
Ｙ＝Ｌ×〔Ｖ_Y ／（Ｖ_X ＋Ｖ_Y ）〕 （７）
式（７）には単位長さあたりの抵抗値Ｒ₀ 、Ｒ₁ が含まれないので、Ｖ_X やＶ_Y が測定されると、近端又は遠端から漏液点Ｐまでの距離Ｘ又はＹは、抵抗線２ａ，導電線３ａの単位長さあたりの導体抵抗値Ｒ₀ 、Ｒ₁ に関係なく得られる。
【００３２】
次に、図４に基づいて、漏液検知システムの第２の実施形態２０について説明する。
漏液検知システム２０は、遮水シートが２枚の場合に適用される（図６参照）。
第１の実施形態１５と異なるところは、遮水シートが、上下２枚の遮水シート６１，６２で構成されるため、漏液位置検知線１を、２枚の遮水シート６１、６２の間に敷設して共用とし、電流ソース線を遮水シート６１の上面に敷設される上側電流ソース線２１と、下側遮水シート６２の下面に敷設される下側電流ソース線２２の２本とし、これらの端部（図示例では、近端Ｊ１，Ｊ２）及び漏液位置検知線の端部（図示例では、近端Ｉ、Ｋ）を検知器２５の端子２６，２７、２８，２９にそれぞれ接続したものである。
【００３３】
検知器２５において、直流電源Ｂ及び電流制御器Ｃからなる定電流電源Ｄは電流計Ａ及び電流ソース線切り替えスイッチＳ２を介して、端子２６，２７に切り替え可能に接続されている。そして、電流ソース線切り替えスイッチＳ２は、端子２６を介して電流ソース線２１に接続される極４７と端子２７を介して電流ソース線２２に接続される極４８と電流計Ａに接続された極４９とを備えている。また、近端遠端切り替えスイッチＳ１は、端子２８，２９間に接続される。近端遠端切り替えスイッチＳ１の構成は、図３の近端遠端切り替えスイッチＳと同じである。そして、直流電圧計Ｖは、近端遠端切り替えスイッチＳ１を介して、抵抗線２ａの両端の電圧を測定できるように接続されている。
【００３４】
次に、動作について説明する。
遮水シート６１の点Ｐ₁ に漏液が生じたときは、電流ソース線切り替えスイッチＳ２を電流ソース線２１側の極４７に接続すると、電流ソース線２１と漏液位置検知線１の抵抗線２ａとの間に漏液Ｅ₁ と半導電性被覆２ｂを介して定電流Ｉｃが流れる。
さらに近端遠端切り換えスイッチＳ１が、近端側に接続されていると、抵抗線 2ａの漏液点Ｐ₁ から近端Ｉへと電流が流れ、端子２８、近端遠端切り換えスイッチＳ１を介して、接地点ｇに流れる。
そのとき、直流電圧計Ｖには、導電線３ａを介して、Ｐ点の電位、すなわち漏液点Ｐから接地点ｇまでの電位差が測定されることになる。以下、図３の漏液検知システムの場合と同様にして漏液点Ｐ₁ の位置が検知できる。
【００３５】
同様にして、遮水シート６２の点Ｐ₂ に漏液Ｅ₂ が生じたときは、電流ソース線切り替えスイッチＳ２を電流ソース線２２側の極４８に接続すると、電流ソース線２２と漏液位置検知線１の抵抗線２ａとの間に漏液Ｅ₂ と半導電性被覆２ｂを介して抵抗線 2ａに定電流Ｉｃが流れる。
近端遠端切り換えスイッチＳ１が、近端側に接続されていると、抵抗線２ａの漏液点Ｐ₂ から近端Ｉへと電流が流れ、端子２９、近端遠端切り替えスイッチＳ１を介して、接地点ｇに流れる。
そのとき、直流電圧計Ｖには、導電線３ａを介して、Ｐ₂ 点の電位、すなわち漏液点Ｐ₂ から接地点ｇまでの電位差が測定されることになる。以下、図3 の漏液検知システムの場合と同様にして漏液点Ｐ₂ の位置が検知できる。
【００３６】
上記漏液検知システムにおいて、漏液位置検知線１と、電流ソース線２１，２２とは、ほぼ平行に配設されるのが好ましいが、遮水シート６１，６２を挟んでともに面状に配設されるようにし、互いに多数の点で交差するようにしてもよい。
漏液位置検知線１及び電流ソース線２１，２２を面状に敷設する方法は、地形に合わせて、全長を適宜の長さごとに折り返し蛇行させつつ面状に形成してもよいし、適宜の長さのものを面状に配設して接続してもよい。
【００３７】
以上の漏液検知システムにおいて、電流ソース線２１、２２は、裸銅線であってもよいが、耐腐食性の点からいえば、被覆抵抗線の半導電性の被覆と同様、半導電性の高分子材料を被覆したものとしてもよい。
また、漏液位置検知線としては、漏液位置検知線１を用いるものとして説明したが、もちろん漏液位置検知線１０を用いたものとしてもよい。
近端遠端切り替えスイッチＳ，Ｓ１及び電流ソース線切り替えスイッチＳ２は，手動スイッチとして説明したが、もちろんリレーや電子スイッチなどを用いても良い。
【００３８】
【実施例】
次に、実施例による漏液位置検知の実例について説明する。
図５において、１は、表１に示す構造・寸法を有する全長６０ｍの漏液位置検知線であり、被覆抵抗線及び被覆リード線の近端Ｉ，Ｋから遠端Ｆ，Ｇまでを１０ｍごとに折り返し蛇行させて面状に敷設した。被覆抵抗線の抵抗線の近端Ｉを、抵抗線用リード線２３を介し、被覆リード線のなかの導電線の遠端Ｇを、被覆リード線用リード線２４を介して、それぞれ検知器２５に接続した。被覆リード線の導電線が、近端Ｋではなく遠端Ｇにおいて検知器２５に接続されている点で、図３及び図４の場合と異なるが、測定原理上変わるところがないことは容易に理解できよう。
【００３９】
【表１】

【００４０】
電流ソース線２１には、４ｍｍの裸軟銅線を用い、次に示すように被覆抵抗線に直接接触させるか又は水道水での水溜りをつくりそれを介して接触させた。
＜測定方法１＞ 電流ソース線２１を漏液位置検知線１の漏液位置模擬点として近端Ｉから５ｍ，１５ｍ，２５ｍ，３５ｍ，４５ｍ、５５ｍの点Ｐ_5,Ｐ_15, Ｐ_25, Ｐ_35, Ｐ_45, Ｐ₅₅に被覆抵抗線２１を順次直接触させて測定した。
＜測定方法２＞ 漏液位置検知線１の漏液位置模擬点Ｐ_5,Ｐ_15, Ｐ_25, Ｐ_35, Ｐ_45, Ｐ₅₅上に水道水の水溜りＥ₅ ，Ｅ₁₅，Ｅ₂₅，Ｅ₃₅，Ｅ₄₅，Ｅ₅₅を順次つくり、その都度その水溜りを介して、電流ソース線２１をその外周と被覆抵抗線の外周との間に２〜３ｍｍの間隔をあけて配設し、測定した。
測定結果を表２に示す。
【００４１】
【表２】

【００４２】
測定結果は、漏液位置模擬点Ｐ_5,Ｐ_15, Ｐ_25, Ｐ_35, Ｐ_45, Ｐ₅₅の近端からの距離を正確に示している。
【００４３】
【発明の効果】
以上に説明したように、本発明の請求項１記載の発明によれば、
抵抗線には、耐液性で半導電性の高分子部材が被覆され、被覆リード線は、導電線の上に耐液性の絶縁部材を被覆してあるので、抵抗線や導電線が腐食されることがなく、また被覆抵抗線の被覆は半導電性であるから、抵抗線を電極として他の電極線との間に電圧を加えれば、電極線間への液体の浸入などによる電気特性の変化を検知することができる。そして、１本の被覆抵抗線と１本の被覆リード線は連接して一体化されているので、曲げ方向が短径方向に限定されるが、抵抗線と導電線との間に剛性のちがいがあってもキンクを生じることがないから、取り扱いが容易である。
【００４４】
請求項２記載の発明によれば、請求項１記載の発明の効果に加えて、
適度の導電性を有する半導電性の高分子部材で被覆された被覆抵抗線が安価に得られるので、漏液位置検知線も安価となる。
【００４５】
請求項３記載の発明によれば、請求項１又は２記載の発明の効果に加えて、
被覆抵抗線と被覆リード線との一括押し出しが可能となり、被覆抵抗線及び被覆リード線の形成と連接・一体化が同時に行われ量産に適している。
【００４６】
請求項４記載の発明によれば、請求項１乃至３のいずれかに記載の発明の効果に加えて、
抵抗線の端部から漏液位置までの導体抵抗を測定することにより、漏液位置の検知ができ、しかも被覆リード線中の導電線を測定用のリード線として用いることができるので測定が容易である。
【００４７】
請求項５記載の発明によれば、請求項１乃至４のいずれかに記載の発明の効果に加えて、
連接・一体化された被覆抵抗線と被覆リード線は、保護編組体により、いっそう確実に一体化され、ばらけたりするおそれがないので丈夫で取り扱いが容易である。
【００４８】
請求項６記載の発明によれば 遮水シートの損傷により、漏液が生じると、漏液位置検知線の抵抗線と、遮水シートを挟んで反対側に敷設された電流ソース線との間に定電流電源からの電流が流れ、電圧測定手段によって抵抗線の両端の電圧を測定すると、抵抗線の端部から漏液点までの距離が分かり、漏液位置が検知できる。また抵抗線には、耐液性で半導電性の高分子部材が被覆され、被覆リード線は、導電線の上に耐液性の絶縁部材を被覆してあるので、抵抗線や導電線が腐食されることがなく、また被覆抵抗線の被覆は半導電性であるから、抵抗線と電流ソース線との間に電圧を加えれば、その間への液体の浸入などによる電気特性の変化を検知することができる。そして、被覆抵抗線と被覆リード線は連接して一体化されているので、曲げ方向が短径方向に限定されるが、抵抗線と導電線との間に剛性のちがいがあってもキンクを生じることがない。したがって、漏液検知システムとして、敷設や取り扱いが容易であり、長期間の使用に耐える。
【００４９】
請求項７記載の発明によれば、請求項６記載の発明の効果に加えて、
上下２枚の遮水シートの間に漏液位置検知線を、上側遮水シートの上面に上側電流ソース線を、下側遮水シートの下面に下側電流ソース線を、それぞれ敷設し、漏液位置検知線中の抵抗線と上側及び下側電流ソース線との間にそれぞれ定電流電源から定電流を供給するようにすれば、電圧測定手段により抵抗線の両端の電圧を測定することにより上下２枚の遮水シートのいずれに損傷が生じてもそこからの漏液を検知し、その位置を検知することができるので、遮水シートが２枚ある場合でも、漏液位置検知が確実に行われ、２枚の使用を容易にする。
【図面の簡単な説明】
【図１】本発明の漏液位置検知線の第１の実施形態の斜視図である。
【図２】本発明の漏液位置検知線の第２の実施形態の斜視図である。
【図３】本発明の漏液検知システムの第１の実施形態の説明図である。
【図４】本発明の漏液検知システムの第２の実施形態の説明図である。
【図５】本発明の実施例による位置検知の実験の説明図である。
【図６】漏液検知システムの使用例の説明図である。
【図７】漏液検知システムの原理の説明図である。
【図８】従来の漏液検知線の斜視図である。
【符号の説明】
１，１０ 漏液位置検知線
２ 被覆抵抗線
２ａ 抵抗線
２ｂ 半導電性の被覆
３ 被覆リード線
３ａ 導電線
３ｂ 絶縁被覆
４ 連接部
１１ 保護編組体
１５，２０ 漏液検知システム
２１，２２ 電流ソース線
２５ 検知器
５０ 廃棄物処分場
６０ 地盤
６１，６２ 遮水シート
Ａ，Ａ１，Ａ２ 直流電流計
Ｃ，Ｃ１，Ｃ２ 電流制御器
Ｄ，Ｄ１，Ｄ２ 定電流電源
Ｖ 直流電圧計[0001]
BACKGROUND OF THE INVENTION
The present invention is used to detect leakage due to damage to a water shielding sheet that blocks outflow of liquid from deposits, etc., and a leakage position detection line suitable for detecting the leakage position, and the same In particular, the present invention relates to a leak position detection line excellent in liquid resistance against a detection target liquid, excellent in mechanical strength and handleability, and a leak detection system using the leak position detection line.
[0002]
[Prior art]
In recent years, as one of environmental problems, countermeasures against leaching of environmental pollutants from waste disposal sites have become a major problem. As a method for disposing of the waste, as shown in FIG. 6, water-impervious sheets 61, 62, etc. are laid in the recesses of the ground 60, and the waste 67 is dumped and deposited thereon, and finally, as it is in the soil. The method of embedding in is adopted. These water shielding sheets 61 and 62 are for preventing harmful substances mixed in the waste 67 and harmful substances generated by chemical reaction during the deposition from entering the ground 60 and contaminating the groundwater. It is. Therefore, assuming various conditions, it is said to have sufficient characteristics both mechanically and chemically, but if it is still damaged due to aging or some condition, the leaked liquid containing harmful substances from there May leach into the ground. Therefore, it is necessary to detect the occurrence of liquid leakage due to damage to the water shielding sheet, and to detect the damage position (leakage position) at an early stage so that measures can be taken.
[0003]
Such a liquid leakage detection system for detecting liquid leakage from the water shielding sheet is proposed in Japanese Patent Application Laid-Open No. 10-300622 and put into practical use.
FIG. 7 is a principle diagram of leak position detection in the leak detection system.
The liquid leakage detection system 30 includes a resistance wire 31a and a conductive wire 32 disposed below the water shielding sheet 61, a current source line 33 disposed above the water shielding sheet 61, and one end of the current source line 33. A constant current power source comprising a DC power source (not shown) and a current controller 36, a voltmeter V for measuring the voltage across the resistance wire 31a, and the constant current power source to the current source line 33 and the resistance wire 31a. And an ammeter A for monitoring current. When the water shielding sheet 61 is damaged and a fracture P is generated, and the liquid E discharged from the waste is leaked from the fracture P, the current source line 33 and the resistance line 31a are brought into conduction by the liquid leakage E, and the ammeter A current Ic flows through A. Therefore, the voltage Vx appearing at both ends of the resistance wire 31a is a potential difference from the breakage (leakage point) P to the ground point G, and the resistance value per unit length of the resistance wire 31a is represented by R. ₀ The length X from the leakage point P of the resistance wire 31a to the ground side end I is such that the potential difference in the lead wire 39 can be ignored.
X = Vx / (R ₀ × Ic) (1)
And the position of the breakage P is known.
[0004]
By the way, in this liquid leakage detection system 30, the following are used as specific examples of the resistance wire 31a, the conductive wire 32, and the current source wire 33.
FIG. 8 shows twisting of a braided resistance wire 31 coated with an internal braid 31b made of polyester fiber yarn on a resistance wire 31a and a coated lead wire 32 coated with a polyvinyl chloride coating 32b on a conductive wire 32a, The liquid leakage position detection wire 30 was coated with an external braided body 33 made of polyester fiber, and a bare copper wire was used as the current source wire 33.
[0005]
As described above, the resistance wire 31a such as a Kanthal wire and the conductive wire 32 made of annealed copper are integrated as the liquid leakage position detection wire 30, so that the handling is easier than arranging them individually. However, if the resistance wire 31a is exposed to leakage, it may corrode and break, and due to the difference in rigidity between the resistance wire 31a and the conductive wire 32a, there is a problem that kinks are likely to occur during laying. there were.
[0006]
[Problems to be solved by the invention]
The present invention is to solve the above problems,
It is an object of the present invention to provide a leakage position detection line that does not corrode the resistance wire, does not cause kinking, and has mechanical strength. It is an object of the present invention to provide a leak detection system capable of reliably detecting the leak position using the leak position detection line.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 of the present invention is arranged substantially in parallel. One Sheathing resistance wire and One Connected and integrated with the coated lead wire,
The covered resistance wire is formed by coating a liquid-resistant and semiconductive polymer member on a resistance wire having a uniform conductor resistance in the length direction,
The covered lead wire is formed by covering a conductive wire with a liquid-resistant insulating member.
[0008]
Here, liquid resistance refers to the property that the characteristics of the liquid to be detected (liquid leaking from the breakage, ie, liquid leakage) are not easily deteriorated, and the function as a covered resistance wire or a covered lead wire is maintained during the period of use. Say.
The resistance wire is coated with a liquid-resistant and semi-conductive polymer member, and the coated lead wire is coated with a liquid-resistant insulating member on the conductive wire. In addition, since the covering of the covering resistance line is semiconductive, if a voltage is applied between the resistance line and another electrode line (for example, a current source line), It is possible to detect a change in electrical characteristics due to liquid intrusion or the like. And One Sheathing resistance wire and One Coated lead wire Toga Since they are connected and integrated, the bending direction is limited to the minor axis direction, but there is no kinking even if there is a difference in rigidity between the resistance wire and the conductive wire, and the resistance wire is covered. Therefore, it has mechanical strength.
[0009]
The invention according to claim 2 is the liquid leakage position detection line according to claim 1,
The covering of the covering resistance wire is made of a polymer member containing conductive powder.
Thereby, the covering resistance wire coat | covered with the semiconductive polymer member which has moderate electroconductivity is obtained cheaply.
[0010]
The invention according to claim 3 is the leakage position detection line according to claim 1 or 2,
The covering resistance wire covering and the insulating member of the covering lead wire are both made of a polymer member whose base material can be extruded.
The covering resistance wire covering and the covering lead wire insulating member are both made of a polymer member whose base material can be extruded.
As a result, batch extrusion becomes possible, and formation, connection, and integration of the covering resistance wire and the covering lead wire are simultaneously performed.
[0011]
According to a fourth aspect of the present invention, in the liquid leakage position detection line according to any one of the first to third aspects,
The conductor resistance of the conductive wire of the covered lead wire is characterized by being negligibly small compared to the conductor resistance of the resistance wire.
Thus, by measuring the conductor resistance from the end of the resistance wire to the leakage position, the leakage position can be detected, and the conductive wire in the covered lead wire can be used as the lead wire.
[0012]
The invention according to claim 5 is the liquid leakage position detection line according to any one of claims 1 to 4,
It has a protective braided body that circumscribes and covers the covering resistance wire and the covering lead wire.
The covered resistance wire and the covered lead wire that are connected and integrated are more reliably integrated by this protective braid, and there is no possibility of being scattered.
[0013]
The invention according to claim 6 is a liquid leakage detection system for detecting liquid leakage due to damage of a water shielding sheet that blocks outflow of liquid from a deposit or the like.
The liquid leakage position detection line according to any one of claims 1 to 5 laid on one side of the water shielding sheet,
A current source line that is laid on the opposite side of the leakage position detection line across the water shielding sheet, and detects a change in electrical characteristics between the resistance line in the leakage position detection line,
A constant current power source for supplying a constant current between the resistance line and the current source line;
Voltage measuring means for measuring the voltage across the resistance wire is provided.
[0014]
If liquid leakage occurs due to damage to the water shielding sheet, current from the constant current power source flows between the resistance line of the leakage detection line and the current source line laid on the opposite side across the water shielding sheet. By measuring the voltage at both ends of the covering resistance wire by the voltage measuring means, the distance from the end of the covering resistance wire to the leakage point can be known, and the leakage position can be detected. The resistance wire is coated with a liquid-resistant and semi-conductive polymer member, and the coated lead wire is coated with a liquid-resistant insulating member on the conductive wire. Because it is not corroded and the sheath of the sheathing resistance wire is semiconductive, if a voltage is applied between the resistance wire and the current source wire, changes in electrical characteristics due to liquid intrusion, etc., can be detected. can do. And since the coated resistance wire and the coated lead wire are connected and integrated, the bending direction is limited to the minor axis direction, but even if there is a difference in rigidity between the resistance wire and the conductive wire, kinks are not formed. It does not occur.
[0015]
The invention according to claim 7 is the liquid leakage detection system according to claim 6,
The water shielding sheet is composed of two upper and lower water shielding sheets,
The liquid leakage position detection line according to any one of claims 1 to 5, which is laid between the two upper and lower water shielding sheets,
An upper current source line laid on the upper surface of the upper water shielding sheet;
A lower current source line laid on the lower surface of the lower water shielding sheet,
A constant current power source for supplying a constant current between the covering resistance line in the leak position detection line and the upper and lower current source lines;
Voltage measuring means for measuring the voltage across the covering resistance wire is provided.
[0016]
When there are two water-impervious sheets, the water-impervious sheet is more reliably formed, and as described above, the liquid leakage position detection line is placed between the upper and lower water-impervious sheets, and the upper current on the upper surface of the upper impermeable sheet Lay the source wire and the lower current source line on the lower surface of the lower water-impervious sheet, and set the current from the constant current power source between the resistance line in the leak detection line and the upper and lower current source lines. If the current is supplied, the voltage at both ends of the resistance wire is measured by the voltage measuring means to detect the leakage from any of the two upper and lower water shielding sheets, and the position Can be detected.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a first embodiment of a leak position detection line of the present invention, FIG. 2 is a perspective view of a second embodiment of a leak position detection line of the present invention, and FIG. FIG. 4 is an explanatory diagram of the second embodiment of the liquid leakage detection system of the present invention, and FIG. 5 is an experiment of position detection according to the embodiment of the present invention. It is explanatory drawing of.
[0018]
In FIG. 1, a liquid leakage position detection wire 1 according to the first embodiment is formed by connecting and connecting a covering resistance wire 2 and a covering lead wire 3 arranged substantially in parallel. The covered resistance wire 2 is obtained by coating a liquid resistant and semiconductive polymer member 2b on a resistance wire 2a having a uniform conductor resistance in the longitudinal direction. A liquid-resistant insulating member 3b is coated thereon.
[0019]
As mentioned earlier, liquid resistance here means that the characteristics of the liquid to be detected (liquid leaking from the breakage, that is, liquid leakage) are unlikely to deteriorate and function as a coated resistance wire or coated lead wire during the period of use. However, depending on the type of the liquid to be detected, if the liquid to be detected is, for example, water, acid or alkali, it means water resistance, acid resistance, and alkali resistance.
[0020]
For the resistance wire 2a, for example, a conductor resistance per unit length such as a Kanthal wire (nickel chrome alloy wire manufactured by Kanthal Gadelius) is high enough to ignore that of the copper wire of the conductive wire 2a or the tinned annealed copper wire. Things are used. This is to reduce the error in detecting the leak position as will be described later.
[0021]
The resistance wire 2a is covered with a liquid-resistant semiconductive polymer member 2b, and the conductive wire 3a is covered with a liquid-resistant insulating member 3b. The wire 3a is not corroded, and the covering 2b of the covering resistance wire 2 is semiconductive. Therefore, if a voltage is applied between the resistance wire 2a and another electrode wire, the interposition between the electrode wires It is possible to detect a change in the electrical characteristics of an object. Further, if the conductive wire 3a of the coated lead wire 3 is used as an electrode wire, the leak position detection line can be used alone as a leak detection line.
[0022]
If the coating 2b of the covering resistance wire 2 is a polymer member containing conductive powder, the semiconductive polymer member 2b having moderate conductivity can be easily obtained by adjusting the content of the conductive powder. As a result, an inexpensive covering resistance wire 2 is obtained.
[0023]
Further, the method 4 for connecting the coated resistance wire 2 and the coated lead wire 3 naturally includes bonding with an appropriate adhesive, but the base of the coated resistance wire coating 2a and the coated lead wire insulating member 3b. If the material is a polymer member that can be extruded together, the coated resistance wire 2 and the coated lead wire 3 can be batch-extruded, and the connected resistance wire 2 and the coated lead wire 3 can be connected and integrated simultaneously. Since it is performed, it is preferable.
[0024]
For example, it is preferable to use a general-purpose plastic such as polyvinyl chloride because the substrate is inexpensive and easy to perform batch extrusion. Further, since only the coating 2a of the coating resistance wire may be used in which conductive powder such as carbon black is mixed, it is also preferable in that a semiconductive coating can be easily obtained.
[0025]
In FIG. 2, the liquid leakage detection wire 10 according to the second embodiment encloses the protective braid 11 on the liquid leakage position detection wire 1 so as to circumscribe the covering resistance wire 2 and the covering lead wire 3. It is a thing.
The covering resistance wire 2 and the covering lead wire 3 are connected and integrated by adhesion, collective extrusion or the like, but by covering the protective braid 11, the covering resistance wire 2 and the covering lead wire 3 are more reliably integrated and scattered. There is no fear.
[0026]
When used as a liquid leakage position detection line, the yarn constituting the protective braided body 11 may have any strength to integrate and hold the covering resistance wire 2 and the covering lead wire 3, but as the liquid leakage detection line, When used, it is preferable in terms of recoverability after a synthetic resin thread such as Tetron gets wet with the liquid leakage. Further, the detection sensitivity can be adjusted by adjusting the density of the protective braid.
[0027]
Next, the leakage detection system of the present invention will be described based on FIG.
FIG. 3 is an explanatory diagram of the outline and operation of the configuration of the first embodiment of the liquid leakage detection system, and is applied to the case where there is one water shielding sheet. In FIG. 3A, the liquid leakage detection system 15 is laid on the opposite side of the liquid leakage position detection line 1 with the water leakage sheet 61 sandwiched between the liquid leakage position detection line 1 and the water shielding sheet 61. A constant current is supplied between the resistance source 2a and the current source line 21 and a current source line 21 for detecting a change in electrical characteristics between the resistance line 2a and the resistance line 2a in the leakage position detection line 1. A current power source D and voltage measuring means V for measuring the voltage across the resistance wire 2a are provided.
[0028]
In the liquid leakage detection system 15, the liquid leakage position detection line 1 has the above-described characteristics, and the characteristics are utilized here.
Then, when liquid leakage E occurs due to damage to the water shielding sheet, it is fixed between the resistance wire 2a of the liquid leakage position detection line 1 and the current source line 21 laid on the opposite side across the water shielding sheet 61. When the constant current Ic from the current power source D flows and the voltage across the resistance wire 2a is measured by the voltage measuring means V, the liquid leakage from the end of the resistance wire is represented by the equation (1) as described in the prior art. The distance to the point is known and the leak position can be detected.
X = Vx / (R ₀ × Ic) (1)
However, since the resistance value of the resistance wire 2a varies depending on the temperature, a near-end / far-end switch S is provided as a system that does not cause this error.
[0029]
The near end far end changeover switch S is composed of main poles 41 and 42, near end side poles 43 and 44, and far end side poles 45 and 46.
In FIG. 3A, the near end far end changeover switch S is connected to the near end side. Therefore, the constant current Ic flows from the [+] side of the DC power source B through the near end J of the current source line 21 and through the leak point P to the resistance line 2a of the leak position detection line. Returning to the near end I, the current flows to the [-] side (ground point g) of the DC power source B through the poles 45 → 44 → 42.
At that time, the DC voltmeter V measures the potential at point P, that is, the potential difference from the leak point P to the near end I, pole 45-44-42 (ground point g) via the conductive wire 3a. become. Since the lead wire resistance from the near end I to the ground point g is negligible compared to the resistance between P-I of the resistance wire 2a, the measured voltage V _X Is approximately equal to the voltage drop across the resistance line 2a. The conductor resistance of the resistance wire 5a is uniform in the length direction, and the conductor resistance value per unit length is R ₀ When the distance from the near end I of the leak position detection line 1 to the leak point P is X, the above formula (1) is obtained.
[0030]
In FIG.3 (b), the near end far end changeover switch S is connected to the far end side. Therefore, the constant current Ic flows from the [+] side of the DC power source B through the near end J of the current source line 21 to the resistance wire 2a via the leak point P and via the far end F. Then, it returns from G to the near end K of the conductive wire 3a, and flows to the [-] side (ground point g) of the DC power supply B via the poles 46 → 42.
At that time, the DC voltmeter V is connected to the potential at the point P via the resistance wire 2a, that is, from the leakage point P via the far ends F and G, the near end K of the conductive wire 3a, the pole 46 → 42 (grounding point). The potential difference up to g) will be measured. Here, the conductor resistance R per unit length of the resistance wire 2a ₀ Is the conductor resistance R per unit length of the conductive wire 2a ₁ Is so large that the voltage drop between P and F of the resistance line 2a is so large that the voltage drop between G and K of the conductive line 3a is negligible. _Y Is approximately equal to the voltage drop across P-F of the resistance wire 2a. The conductor resistance of the resistance wire 2a is uniform in the length direction, and the conductor resistance value per unit length is R ₀ The conductor resistance value per unit length of the conductive wire 3a is R ₁ And the distance from the leak point P to the far end F is Y, and the total length of the leak position detection line is L,
V _Y = Ic × [(R ₀ × Y) + (R ₁ × L)] (2)
[0031]
Ic, R ₀ , R ₂ , L is known, the distance X or Y from the equations (1) and (2) to the leak point can be determined.
Therefore, dividing both sides of equation (2) by both sides of equation (1),
V _Y / V _X = [(R ₀ × Y) + (R ₁ × L)] / (R ₀ × X) (3)
However,
L = X + Y (4)
Because

Conductor resistance R per unit length of the conductive wire 3a ₁ Is the conductor resistance R per unit length of the resistance wire 2a ₀ If it is small enough to be ignored as compared to, the following approximate expression holds.
V _Y / V _X ≒ Y / X (5)
From equation (4)
Y = L-X
Therefore, if this is substituted into equation (5),
V _Y / V _X ≒ (L / X) -1
X = L × [V _X / (V _X + V _Y ] (6)
Similarly,
Y = L × [V _Y / (V _X + V _Y ] (7)
Equation (7) shows the resistance value R per unit length. ₀ , R ₁ Is not included, so V _X Or V _Y Is measured, the distance X or Y from the near end or the far end to the leakage point P is the conductor resistance value R per unit length of the resistance wire 2a and the conductive wire 3a. ₀ , R ₁ Can be obtained regardless of
[0032]
Next, a second embodiment 20 of the liquid leakage detection system will be described based on FIG.
The liquid leakage detection system 20 is applied when there are two water shielding sheets (see FIG. 6).
The difference from the first embodiment 15 is that the water shielding sheet is composed of two upper and lower water shielding sheets 61 and 62, so that the liquid leakage position detection line 1 is connected to the two water shielding sheets 61 and 62. Two current source lines are laid between the upper current source line 21 laid on the upper surface of the water shielding sheet 61 and the lower current source line 22 laid on the lower surface of the lower water shielding sheet 62. These ends (near ends J1, J2 in the illustrated example) and the ends (near ends I, K in the illustrated example) of the leakage position detection line are connected to the terminals 26, 27, 28, 29 of the detector 25. Are connected to each other.
[0033]
In the detector 25, a constant current power source D including a DC power source B and a current controller C is connected to terminals 26 and 27 through an ammeter A and a current source line changeover switch S2 so as to be switchable. The current source line changeover switch S2 includes a pole 47 connected to the current source line 21 via the terminal 26, a pole 48 connected to the current source line 22 via the terminal 27, and a pole connected to the ammeter A. 49. Further, the near-end / far-end selector switch S <b> 1 is connected between the terminals 28 and 29. The configuration of the near end far end changeover switch S1 is the same as that of the near end far end changeover switch S of FIG. And the direct-current voltmeter V is connected so that the voltage of the both ends of the resistance wire 2a can be measured via the near end far end changeover switch S1.
[0034]
Next, the operation will be described.
Point P of the water shielding sheet 61 ₁ When leakage occurs in the current source line, if the current source line changeover switch S2 is connected to the pole 47 on the current source line 21 side, the leakage E between the current source line 21 and the resistance line 2a of the leakage position detection line 1 is detected. ₁ And a constant current Ic flows through the semiconductive coating 2b.
Furthermore, when the near end far end changeover switch S1 is connected to the near end side, the leakage point P of the resistance wire 2a. ₁ Current flows from the near end I to the near end I, and flows to the ground point g via the terminal 28 and the near end far end changeover switch S1.
At that time, the DC voltmeter V measures the potential at the point P, that is, the potential difference from the leakage point P to the ground point g via the conductive wire 3a. Hereinafter, in the same manner as in the case of the leak detection system of FIG. ₁ Can be detected.
[0035]
Similarly, point P of the water shielding sheet 62 ₂ Leakage E ₂ When the current source line changeover switch S2 is connected to the pole 48 on the current source line 22 side, the liquid leakage E occurs between the current source line 22 and the resistance line 2a of the liquid leakage position detection line 1. ₂ A constant current Ic flows through the resistance wire 2a through the semiconductive coating 2b.
When the near end far end changeover switch S1 is connected to the near end side, the leakage point P of the resistance wire 2a ₂ Current flows from the near end I to the near end I and flows to the ground point g via the terminal 29 and the near end far end changeover switch S1.
At that time, the DC voltmeter V is connected to P through the conductive wire 3a. ₂ Point potential, that is, leak point P ₂ To the ground point g is measured. The leak point P is the same as in the leak detection system of FIG. ₂ Can be detected.
[0036]
In the liquid leakage detection system, the liquid leakage position detection line 1 and the current source lines 21 and 22 are preferably arranged substantially in parallel, but are arranged in a planar shape with the water shielding sheets 61 and 62 interposed therebetween. It may be provided and may intersect with each other at many points.
The method of laying the liquid leakage position detection line 1 and the current source lines 21 and 22 in a planar shape may be formed in a planar shape while being meandered by an appropriate length according to the topography. The thing of length of this may be arrange | positioned and connected in planar shape.
[0037]
In the above leakage detection system, the current source wires 21 and 22 may be bare copper wires, but in terms of corrosion resistance, they are semiconductive as in the case of the semiconductive coating of the coated resistance wires. The polymer material may be coated.
In addition, the liquid leakage position detection line has been described as using the liquid leakage position detection line 1, but of course, the liquid leakage position detection line 10 may be used.
Although the near-end / far-end changeover switches S and S1 and the current source line changeover switch S2 have been described as manual switches, of course, relays, electronic switches, or the like may be used.
[0038]
【Example】
Next, an example of leakage position detection according to the embodiment will be described.
In FIG. 5, reference numeral 1 denotes a leakage position detection line having a total length of 60 m having the structure and dimensions shown in Table 1. Every 10 m from the near end I, K to the far end F, G of the covering resistance wire and covering lead wire It was made to meander and laid in a plane. The near end I of the resistance wire of the covered resistance wire is passed through the lead wire 23 for resistance wire, and the far end G of the conductive wire in the covered lead wire is connected to the detector 25 via the lead wire 24 for covered lead wire. Connected to. Although it differs from the case of FIG. 3 and FIG. 4 in that the conductive wire of the coated lead wire is connected to the detector 25 at the far end G instead of the near end K, it is easily understood that there is no change in the measurement principle. I can do it.
[0039]
[Table 1]

[0040]
A 4 mm bare soft copper wire was used as the current source line 21, and was directly brought into contact with the coated resistance wire as shown below, or a water reservoir was formed through tap water and brought into contact therewith.
<Measuring Method 1> Using the current source line 21 as a leakage position simulation point of the leakage position detection line 1, a point P of 5 m, 15 m, 25 m, 35 m, 45 m, and 55 m from the near end I. _Five, P _15, P _{twenty five,} P _35, P _45, P ₅₅ The coating resistance wires 21 were sequentially brought into direct contact with each other and measured.
<Measuring method 2> Leak position simulation point P of the leak position detection line 1 _Five, P _15, P _{twenty five,} P _35, P _45, P ₅₅ A puddle of tap water E _Five , E ₁₅ , E _{twenty five} , E ₃₅ , E ₄₅ , E ₅₅ Each time, the current source line 21 was disposed with an interval of 2 to 3 mm between the outer periphery and the outer periphery of the covering resistance wire through the water reservoir and measured.
The measurement results are shown in Table 2.
[0041]
[Table 2]

[0042]
The measurement result is the simulated leak position P _Five, P _15, P _{twenty five,} P _35, P _45, P ₅₅ The distance from the near end of is accurately shown.
[0043]
【The invention's effect】
As described above, according to the first aspect of the present invention,
The resistance wire is coated with a liquid-resistant and semi-conductive polymer member, and the coated lead wire is coated with a liquid-resistant insulating member on the conductive wire. In addition, since the coating of the coated resistance wire is semiconductive, if a voltage is applied between another electrode wire using the resistance wire as an electrode, the electrical characteristics due to liquid intrusion between the electrode wires, etc. Changes can be detected. And One Sheathing resistance wire and One Since the coated lead wire is connected and integrated, the bending direction is limited to the minor axis direction, but there is no kink even if there is a difference in rigidity between the resistance wire and the conductive wire. Easy to handle.
[0044]
According to the invention of claim 2, in addition to the effect of the invention of claim 1,
Since the covering resistance wire covered with the semiconductive polymer member having appropriate conductivity can be obtained at a low cost, the liquid leakage position detection wire is also inexpensive.
[0045]
According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2,
The covered resistance wire and the covered lead wire can be extruded together, and the formation, connection and integration of the covered resistance wire and the covered lead wire are performed at the same time, which is suitable for mass production.
[0046]
According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3,
By measuring the conductor resistance from the end of the resistance wire to the leak position, the leak position can be detected, and the conductive wire in the coated lead wire can be used as a measurement lead wire, making measurement easy It is.
[0047]
According to the invention of claim 5, in addition to the effect of the invention of any of claims 1 to 4,
The connected and integrated covered resistance wire and the covered lead wire are more reliably integrated by the protective braid, and are strong and easy to handle because there is no risk of loosening.
[0048]
According to the sixth aspect of the present invention, when leakage occurs due to damage to the water shielding sheet, the gap between the resistance line of the leakage position detection line and the current source line laid on the opposite side across the water shielding sheet When a current from the constant current power source flows and the voltage at both ends of the resistance wire is measured by the voltage measuring means, the distance from the end of the resistance wire to the leak point can be known, and the leak position can be detected. The resistance wire is coated with a liquid-resistant and semi-conductive polymer member, and the coated lead wire is coated with a liquid-resistant insulating member on the conductive wire. Because it is not corroded and the sheath of the sheathing resistance wire is semiconductive, if a voltage is applied between the resistance wire and the current source wire, changes in electrical characteristics due to liquid intrusion, etc., can be detected. can do. And since the coated resistance wire and the coated lead wire are connected and integrated, the bending direction is limited to the minor axis direction, but even if there is a difference in rigidity between the resistance wire and the conductive wire, kinks are not formed. It does not occur. Therefore, it is easy to install and handle as a leakage detection system, and withstands long-term use.
[0049]
According to the invention of claim 7, in addition to the effect of the invention of claim 6,
Leakage position detection lines between the upper and lower water shielding sheets, the upper current source line on the upper surface of the upper water shielding sheet, and the lower current source line on the lower surface of the lower water shielding sheet are laid. If a constant current is supplied from the constant current power source between the resistance line in the liquid position detection line and the upper and lower current source lines, the voltage at both ends of the resistance line is measured by the voltage measuring means. If any of the two upper and lower water-impervious sheets is damaged, it can detect the leaked liquid and detect its position, so even if there are two sheets of water-impervious sheet, the liquid leak position can be detected reliably. To facilitate the use of two sheets.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first embodiment of a leak position detection line according to the present invention.
FIG. 2 is a perspective view of a second embodiment of a leak position detection line of the present invention.
FIG. 3 is an explanatory diagram of a first embodiment of a leak detection system of the present invention.
FIG. 4 is an explanatory diagram of a second embodiment of the leak detection system of the present invention.
FIG. 5 is an explanatory diagram of an experiment of position detection according to an embodiment of the present invention.
FIG. 6 is an explanatory diagram of a usage example of a leak detection system.
FIG. 7 is an explanatory diagram of the principle of a leakage detection system.
FIG. 8 is a perspective view of a conventional leak detection line.
[Explanation of symbols]
1,10 Leak position detection line
2 Insulation resistance wire
2a Resistance wire
2b Semiconductive coating
3 Coated lead wire
3a Conductive wire
3b Insulation coating
4 connecting parts
11 Protective braid
15, 20 Leak detection system
21, 22 Current source line
25 Detector
50 Waste disposal site
60 ground
61,62 Waterproof sheet
A, A1, A2 DC ammeter
C, C1, C2 Current controller
D, D1, D2 constant current power supply
V DC voltmeter

Claims (7)

One covering resistance wire and one covering lead wire arranged substantially in parallel are connected and integrated,
The covered resistance wire is formed by coating a liquid-resistant and semiconductive polymer member on a resistance wire having a uniform conductor resistance in the length direction,
The covered lead wire is formed by covering a conductive wire with a liquid-resistant insulating member. In the leak position detection line according to claim 1,
The covering of the covering resistance wire is made of a polymer member containing conductive powder, and the liquid leakage position detection wire. In the leak position detection line according to claim 1 or 2,
The covering member of the covering resistance wire and the insulating member of the covering lead wire are made of a polymer member whose base material can be extruded together. In the leak position detection line according to any one of claims 1 to 3,
The liquid leakage position detection line, wherein the conductor resistance of the conductive wire of the covered lead wire is negligibly small as compared with the conductor resistance of the resistance wire of the covered resistance wire. In the leak position detection line according to any one of claims 1 to 4,
A liquid leakage position detection line comprising a protective braid that encloses and covers the covering resistance wire and the covering lead wire. In a leak detection system that detects leaks due to damage to the water shielding sheet that blocks outflow of liquid from sediments, etc.,
The liquid leakage position detection line according to any one of claims 1 to 5 laid on one side of the water shielding sheet,
A current source line that is laid on the opposite side of the leakage position detection line across the water shielding sheet, and detects a change in electrical characteristics between the resistance line in the leakage position detection line,
A constant current power source for supplying a constant current between the resistance line and the current source line;
A liquid leakage detection system comprising voltage measuring means for measuring a voltage across the resistance wire. The liquid leakage detection system according to claim 6,
The water shielding sheet is composed of two upper and lower water shielding sheets,
The liquid leakage position detection line according to any one of claims 1 to 5, which is laid between the two upper and lower water shielding sheets,
An upper current source line laid on the upper surface of the upper water shielding sheet;
A lower current source line laid on the lower surface of the lower water shielding sheet,
A constant current power source for supplying a constant current between the resistance line in the leak position detection line and the upper and lower current source lines;
A liquid leakage detection system comprising voltage measuring means for measuring a voltage across the resistance wire.

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