JPH0544761Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a water leakage detection device, more specifically,
For example, in a buried heat supply piping system such as a district heating plant, two bare electric wires are placed almost parallel in a place where there is a risk of water leakage, and the two electric wires are electrically connected at the point where water leakage occurs. The present invention relates to a device for detecting water leakage based on a short circuit.

Conventional Technology and Problems with the Invention Conventionally, this type of water leakage detection device measures resistance by detecting the current value between two bare wires placed close to each other in parallel, and a positive electrode and a negative electrode. One end of the first wire is connected to the positive electrode of the resistance meter, one end of the second wire is connected to the negative electrode of the resistance meter, and the other ends of the two wires are open. It has been known. With this device,
When there is no water leakage, the two wires are electrically insulated and the resistance between them becomes infinite; when water leakage occurs, the two wires are electrically shorted and the resistance between them becomes infinite. By decreasing,
It is possible to detect the occurrence of water leakage.

However, although this device can detect the occurrence of water leakage, it cannot identify the location where water leakage occurs.

If you divide the water leak detection point into multiple sections and install a water leak detection device like the one above in each section, you will be able to identify the location where the water leak occurs.
This increases costs.

There is also a device that can identify the location of a water leak by applying an electrical pulse from one end of the water leakage detection location and measuring the reflected waves due to changes in impedance caused by the water leakage, but these devices are more expensive.

The purpose of this invention is to provide a water leakage detection device that can solve the above problems, identify the location of water leakage, and can be constructed at low cost.

Means for Solving the Problem The water leakage detection device according to this invention uses two bare wires placed close to each other in parallel, and an ohmmeter that measures resistance by detecting the current value between the positive and negative electrodes. A water leakage detection device comprising: one end of the first electric wire connected to the positive electrode of the resistance meter, one end of the second electric wire connected to the negative electrode of the resistance meter, and the other ends of the two electric wires open. In the first electric wire, a plurality of rectifying elements are inserted at predetermined intervals such that the direction from the ohmmeter side to the open end side is the forward direction, and the first rectifying element is inserted into the second electric wire. The same number of rectifying elements as the rectifying elements of the electric wire,
in close proximity to a corresponding one of the rectifying elements of the first electric wire;
and each wire is inserted at a predetermined interval so that the direction from the open end side to the resistance meter side is the forward direction, and each wire is divided into a plurality of sections by a rectifier,
This is characterized in that a terminal for resistance measurement is provided in each section of each electric wire.

Effect When there is no water leakage at the location where the electric wires are placed,
Since the two wires are electrically insulated, the resistance value between them is infinite, and since no current flows between the positive and negative terminals of the ohmmeter, the measured value of the ohmmeter is infinite. becomes. When a water leak occurs and two wires are electrically shorted in a certain section, the first wire from the positive terminal of the ohmmeter to the short circuit point and the second wire from the short circuit point to the negative terminal of the ohmmeter. Since a forward voltage is applied to the rectifying element in that part, a current flows between the positive and negative electrodes of the ohmmeter, and the measured value of the ohmmeter decreases. Therefore, the occurrence of water leakage can be detected when the measured value of the resistance meter decreases from infinity.

Once water leakage has been detected in this way, remove the resistance meter from one end of the two wires, and for each section, connect the first section in order from the original resistance meter side.
The positive electrode of the ohmmeter is connected to the terminal of the second electric wire section, and the negative electrode of the ohmmeter is connected to the terminal of the second electric wire section, and the resistance values are sequentially measured. Until reaching the compartment where the water leak is occurring, as above, the rectifying element in the first wire from the positive electrode of the ohmmeter to the short circuit point and the second wire from the short circuit point to the negative electrode of the ohmmeter. Since the voltage in the direction is applied, the measured value of the ohmmeter is low. Even in areas where water leaks occur, current flows from the positive terminal of the ohmmeter to the negative terminal of the ohmmeter through the short circuit, so the measured value of the ohmmeter is low. In the section next to the section where the water leakage has occurred, connect the rectifying element in the first wire from the positive electrode of the ohmmeter to the short circuit point and the second wire from the short circuit point to the negative electrode of the ohmmeter in the opposite direction. Voltage is applied, and the open ends of the two wires are electrically insulated from the resistance meter connection point, so no current flows between the positive and negative electrodes of the resistance meter, and the resistance meter The measured value becomes infinite. Therefore, this makes it possible to specify the location where water leakage occurs.

When the occurrence of water leakage is detected, the location where water leakage occurs can be identified in almost the same way by sequentially measuring the resistance value in each compartment starting from the original open end side compartment. I can do it.

Embodiments Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 shows the basic configuration of a water leak detection device according to this invention, and FIG. 2 shows an example of its specific configuration. In the following description, for convenience, the left and right sides of the drawings are referred to as left and right.

In FIG. 1 showing the basic configuration, the water leakage detection device detects the current value between two bare electric wires 1 and 2 arranged close to each other in parallel, and a positive electrode 3a and a negative electrode 3b. It is equipped with a resistance meter 3 for measuring resistance. The right end of the first electric wire 1 is connected to the positive electrode 3a of the resistance meter 3, the right end of the second electric wire 2 is connected to the negative electrode 3b of the resistance meter 3, and the left ends of the two electric wires 1 and 2 are opened to form an open end. 1a, 2a.

In the first electric wire 1, n diodes (rectifiers) A are inserted at predetermined intervals, and in the second electric wire 2, the same number (n) of diodes A as in the first electric wire 1 are inserted. A diode B is inserted at a predetermined interval so as to be close to the corresponding one of the diode A of the first wire 1, so that each wire 1, 2
is divided into a plurality of sections C and D by diodes A and B. As shown in FIG. 1, the diodes A and B are arranged in order from the right to the first diode A
1, B1, second diode A2, B2, third diode A3, B3, fourth diode A4, B4,
5th diode A5, B5, ..., n-2nd diode An-2, Bn-2, n-1st diode
We will call them An-1, Bn-1 and n-th diode An, Bn, and the sections C and D are, in order from the right, the 0th section C0, D0, the 1st section C1, D1, and the 2nd section C.
2, D2, third section C3, D3, fourth section C4,
D4, 5th section C5, D5,..., n-2nd section
Cn-2, Dn-2, n-1st section Cn-1, Dn-
1. We will call them the n-th sections Cn and Dn. The diode A of the first electric wire 1 is inserted so that the direction from the resistance meter 3 side to the open end 1a side is the forward direction,
The diode B of the second electric wire 2 is inserted so that the direction from the open end 2a side to the resistance meter 3 side is the forward direction.

A leader line E,
Terminals G and H for resistance measurement are provided close to the ends of the lead wires E and F of each section C and D, respectively. As shown in Figure 1, terminals G and H are
Corresponding to sections C and D, in order from the right, the first terminal G
1, H1, second terminal G2, H2, third terminal G3,
H3, 4th terminal G4, H4, 5th terminal G5, H
5,..., n-2nd terminal Gn-2, Hn-2, n-th terminal
-1 terminal Gn-1, Hn-1 and n-th terminal Gn, Hn. The same applies to the leader lines E and F.

From the first section C1, D1 of the electric wires 1, 2 to the n-1th section
Parts up to section Cn-1 and Dn-1 and section 0 C
At least a portion of the 0, D0 and n-th sections Cn, Dn are placed in a location where there is a risk of water leakage, such as under underground pipes. The resistance meter 3 is placed at an appropriate location, such as a control room on the ground, and the terminals G and H are placed at an appropriate location, such as near the resistance meter 3 or inside a terminal box installed on the ground. .

Detection of water leakage and identification of the location of water leakage by the water leakage detection device shown in FIG. 1 are performed, for example, as follows.

When there is no water leakage in either section C or D, the two electric wires 1 and 2 are electrically insulated, so the resistance value between them is infinite.
Since no current flows between the positive electrode 3a and the negative electrode 3b of the resistance meter 3, the measured value of the resistance meter 3 becomes infinite.

For example, if a water leak occurs in the third section C3, D3, as shown by the broken line in FIG.
When the two wires 1, 2 are electrically short-circuited at D3, diodes A1, A2,
A3 and the diode B3 in the part of the second electric wire 2 from the short-circuit point I to the negative electrode 3b of the resistance meter 3,
Since a forward voltage is applied to B2 and B1, a current flows between the positive electrode 3a and the negative electrode 3b of the resistance meter 3,
The measured value of resistance meter 3 decreases. Therefore, as the measured value of resistance meter 3 decreases from infinity,
Occurrence of water leakage is detected.

Once the occurrence of a water leak is detected in this manner, the location where the water leak has occurred can be specified by either the first method or the second method below.

In the case of the first method, remove the resistance meter 3 from the right end of the two electric wires 1 and 2, and connect the positive electrode 3a of the resistance meter 3 to the terminal G of the first electric wire 1 in order from the right side for each section C and D. The negative electrode 3b of the resistance meter 3 is connected to the terminal H of the second electric wire 2, respectively, and the resistance values are sequentially measured. In this case, first, the first section C1, D
The resistance meter 3 is connected to the terminals G1 and H1 of the first electric wire 1, but at this time, the diode A2,
A3 and the diode B3 in the part of the second electric wire 2 from the short-circuit point I to the negative electrode 3b of the resistance meter 3,
Since a forward voltage is applied to B2, the resistance meter 3
The measured value of is low. Next, when the resistance meter 3 is connected to the terminals G2 and H2 of the second sections C2 and D2, the diode A3 in the first electric wire 1 from the positive electrode 3a of the resistance meter 3 to the short circuit point I and the short circuit point I
Since a forward voltage is applied to the diode B3 in the portion of the second electric wire 2 from the negative electrode 3b of the resistance meter 3 to the negative electrode 3b of the resistance meter 3, the measured value of the resistance meter 3 is low. Next, the terminal G3 of the third section C3, D3 where water leakage has occurred,
When the resistance meter 3 is connected to H3, the negative electrode 3 of the resistance meter 3 is connected from the positive electrode 3a of the resistance meter 3 through the short circuit point I.
Since current flows through b, the measured value of resistance meter 3 is low. When the resistance meter 3 is connected to the terminals G4, H4 of the fourth section C4, D4 next to the third section C3, D3 where water leakage occurs, the first A voltage in the opposite direction is applied to the diode A4 in the part of the electric wire 1 and the diode B4 in the part of the second electric wire 2 from the short-circuit point I to the negative electrode 3b of the resistance meter 3. Since the portions closer to the open ends 1a and 2a than the sections C4 and D4 to which the resistance meter 3 is connected are electrically insulated, no current flows between the positive electrode 3a and the negative electrode 3b of the resistance meter 3, and the resistance meter The measured value of 3 becomes infinity. Therefore, this makes it possible to know that water leakage has occurred in the third sections C3 and D3. That is, when the measured value of the resistance meter 3 reaches infinity for the first time, it can be known that water leakage has occurred in the sections C and D before that. Furthermore, when the measured value of the resistance meter 3 connected to the n-th terminals Gn and Hn is low in the last n-th section Cn and Dn, it is determined that water leakage has occurred in the n-th section Cn and Dn. be able to.

In the case of the second method, contrary to the first method, for each section C and D, the resistance meter 3 is connected to the terminals G and H in order from the left side, and the resistance value is sequentially measured.
In this case, first, the terminal Gn of the n-th section Cn, Dn,
Connect resistance meter 3 to Hn, but the positive terminal 3 of resistance meter 3
Diodes An, An- in the part of the first electric wire 1 from a to the short-circuit point I of the third section C3, D3
1, An-2...A5, A4 and diodes B4, B5...Bn-2, Bn- in the part of the second electric wire 2 from the short-circuit point I to the negative electrode 3b of the resistance meter 3
Since voltages in the opposite directions are applied to 1 and Bn, and the parts on the open ends 1a and 2a side of the sections Cn and Dn where the resistance meters 3 of the two electric wires 1 and 2 are connected are electrically insulated, No current flows between the positive electrode 3a and the negative electrode 3b of the resistance meter 3, and the measured value of the resistance meter 3 becomes infinite. The same applies to each of the sections C and D from the n-1st section Cn-1, Dn-1 to the fourth section C4, D4. Next, when the resistance meter 3 is connected to the terminals G3 and H3 of the third sections C3 and D3 where water leakage has occurred, the positive terminal of the resistance meter 3
Since current flows from a to the negative electrode 3b of the resistance meter 3 through the short-circuit point I, the measured value of the resistance meter 3 decreases. Therefore, as a result, the third section C3,D
You can tell that a water leak has occurred in step 3. That is, when the measured value of the resistance meter 3 becomes low for the first time, it can be known that water leakage has occurred in the sections C and D. In addition, if the measured value of the resistance meter 3 connected to the first terminals G1 and H1 is infinite in the last first section C1 and D1, it is assumed that water leakage has occurred in the 0th section C0 and D0. can be judged.

As is clear from the explanation of the two methods above,
If a water leak occurs in a plurality of sections C and D at the same time and an electrical short circuit occurs, the water leak location closest to the open ends 1a and 2a will be identified as the water leak occurrence location.

In the above explanation, the resistance meter 3 is placed on the right end of the wires 1 and 2.
is constantly connected to detect water leakage, but
Even if the resistance meter 3 is periodically connected and inspected, the occurrence of water leakage can be similarly detected.

In FIG. 2 showing a specific configuration, a heat insulating material 4
A pipe 5 covered with is buried underground. 2
The electric wires 1 and 2 are embedded in the heat insulating material 4 below the piping 5. Diodes A and B inserted into the electric wires 1 and 2 are also embedded in the heat insulating material 4. The lead wires E, F connected to the sections C, D of the electric wires 1, 2 are drawn out from the insulation material 4 to the ground, and the terminals G,
H is placed in a terminal box J installed on the ground.

The specific configuration of the water leakage detection device is not limited to that shown in FIG. 2, but may be changed as appropriate depending on the situation of the water leakage detection location. Furthermore, this invention can be applied to things other than water leakage detection in piping.

Effects of the invention As mentioned above, the water leakage detection device of this invention can detect the occurrence of water leakage and identify the location where the water leakage occurs, and it only requires adding multiple rectifying elements and lead wires to the conventional device. It can be constructed at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, with FIG. 1 being a block diagram showing one example of the basic structure, and FIG. 2 being a vertical sectional view of a main part showing one example of the specific structure. 1, 2...Bare electric wire, 1a, 2a...Open end, 3
...Resistance meter, 3a...Positive electrode, 3b...Negative electrode, A,
B...diode (rectifier), C, D... section,
G, H...Terminals for resistance measurement.

Claims (1)

[Claims for Utility Model Registration] The utility model is equipped with two bare electric wires arranged close to each other in parallel, and an ohmmeter that measures resistance by detecting the current value between the positive and negative electrodes. In a water leakage detection device, one end of the first wire is connected to the positive electrode of the ohmmeter, one end of the second wire is connected to the negative electrode of the ohmmeter, and the other ends of the two wires are open. , a plurality of rectifying elements are inserted at predetermined intervals so that the direction from the ohmmeter side to the open end side is the forward direction, and the same number of rectifying elements as the first electric wire are inserted into the second electric wire. The rectifying element is
in close proximity to a corresponding one of the rectifying elements of the first electric wire;
and each wire is inserted at a predetermined interval so that the direction from the open end side to the resistance meter side is the forward direction, and each wire is divided into a plurality of sections by a rectifier,
A water leak detection device characterized in that each section of each electric wire is provided with a terminal for measuring resistance.