JP2018184798A - Water leakage detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect water leakage in a water service pipe.SOLUTION: A water leakage detection device for a water service pipe comprises: a detection pipe which is disposed in the water service pipe at a downstream side of first shut valve provided in the water service pipe, one end side of which is communicated with the water service pipe and the other end of which is positioned under the water service pipe; a second shut valve provided in the detection pipe; a sensor detecting the presence or absence of water leakage from the detection pipe; and a control unit determining the presence or absence of water leakage in the water service pipe using detected values of the sensor. The control unit determines that there is water leakage in the water service pipe at a downstream side of the first shut valve, when the sensor detects water outflow, in a state in which the first shut valve is closed and the second shut valve is opened.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water leak detection device for water pipes.

  In patent document 1, the method of detecting the water leak of a cogeneration system is disclosed. The cogeneration system includes a supply-side water circulation path, a reception-side water circulation path, a heat exchanger that exchanges heat between water circulating in the supply-side water circulation path and water circulating in the reception-side water circulation path, and a reception side A heating water tank that communicates with the water circulation path and stores water, a water level detection unit installed in the heating water tank, a control device, and a timer are provided. In the heat exchanger, the supply-side water circulation path and the reception-side water circulation path are separated by a partition, and the pressure of the supply-side water circulation path is higher than the pressure of the reception-side water circulation path. When the water level detector detects that the water level of the heating water tank has reached a predetermined water level, the control device operates a timer to measure the time until the warning water level is reached, and the measured time is a predetermined time set in advance. If it is within the range, it is determined that water leakage has occurred due to breakage of the partition wall of the heat exchanger and intrusion of water in the supply-side water circulation path into the reception-side water circulation path.

JP 2004-257714 A

  In the prior art of Patent Document 1, the leaked water is stored in the heating water tank, and the leakage is detected by a water level gauge. However, since there is no circulation path like patent document 1 in a water pipe, it is difficult to apply the technique of patent document 1 to the water leak detection of a water pipe. Therefore, conventionally, there has been a demand for a technique that can detect water leakage in a water pipe with a simple configuration.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one form of this invention, the water leak detection apparatus for water pipes is provided. The water leakage detection device is installed in the water pipe downstream of the first shut valve provided in the water pipe, one end communicates with the water pipe, and the other end is located below the water pipe. A detection pipe, a second shut valve provided in the detection pipe, a sensor for detecting the presence / absence of water outflow from the detection pipe, and the presence / absence of water leakage in the water pipe are determined using a detection value of the sensor. And a control device. When the sensor detects that the water has flowed out with the first shut valve closed and the second shut valve open, the control device may be located downstream of the first shut valve. It is determined that there is water leakage in the water pipe.
According to the water leakage detection device of this aspect, when there is water leakage in the water pipe, it can be detected by the sensor that water flows out of the detection pipe, so that water leakage in the water pipe can be detected with a simple configuration.

(2) In the water leakage detection device of the above aspect, when there is no water leakage in the water pipe, water from the detection pipe is in a state where the first shut valve is closed and the second shut valve is open. An outflow prevention means for preventing the outflow of the liquid may be provided.
According to the water leakage detection device of this aspect, when there is no water leakage in the water pipe, the outflow prevention means prevents water from flowing out from the detection pipe. By detecting the outflow of water, it is possible to reliably detect water leakage in the water pipe.

(3) In the water leakage detection device according to the above aspect, the outflow prevention means may be configured such that the inner diameter of the other end of the detection pipe is the surface tension of the water surface located at the other end with the second shut valve open. It is good also as what includes that the air is set so thin that it does not enter into the detection pipe.
According to the water leakage detection device of this embodiment, the other end of the detection pipe is set to be thin, so that when there is no water leakage in the water pipe, air is introduced into the detection pipe by the surface tension of the water surface located at the other end. Intrusion can be suppressed and water does not flow out of the detection pipe. On the other hand, if there is water leakage in the water pipe, water continues to flow out of the detection pipe, so that the water leakage can be detected by the sensor.

(4) In the water leakage detection device according to the above aspect, when water is exposed to the outside from the opening at the other end of the detection pipe, the exposed portion of water is M [kg], and the exposed portion When the surface tension of water is γ [N / m] and the gravitational acceleration is g [m / s ² ], the inner diameter D [m] of the other end is given by the following formula: π × γ × D ≧ M It may be set so as to satisfy xg.
According to the water leakage detection device of this aspect, even when water is exposed to the outside from the opening at the other end of the detection pipe with no water leakage in the water pipe, the water does not flow out from the detection pipe. On the other hand, if there is water leakage in the water pipe, water continues to flow out of the detection pipe, so that the water leakage can be detected by the sensor.

(5) In the water leakage detection device of the above aspect, the outflow prevention means includes a container that is installed at a position below the other end of the detection pipe and that stores water flowing out of the detection pipe, The detection pipe may be configured so as to be able to accommodate water up to a water level higher than the height of the opening at the other end.
According to the water leakage detection device of this aspect, when there is no water leakage in the water pipe, when the second shut valve opens, water flows out from the detection pipe and is stored in the container, and the water surface in the container is the other end of the detection pipe. When it reaches the opening of the section, the outflow of water stops. On the other hand, if there is water leakage in the water pipe, water continues to flow out of the detection pipe, so that the water leakage can be detected by the sensor.

(6) In the water leakage detection device of the above aspect, the outflow prevention means may include a decompression pump that is installed in the water pipe downstream from the first shut valve and reduces the pressure in the water pipe.
According to the water leakage detection device of this aspect, the pressure reducing pump reduces the pressure in the water pipe, so that a negative pressure can be generated in the water pipe. Therefore, when there is no water leakage in the water pipe, the gravity applied to the water in the detection pipe, the atmospheric pressure applied to the water surface located at the other end of the detection pipe, and the negative pressure generated by the decompression pump are balanced. Water does not flow out from the detection pipe. On the other hand, if there is water leakage in the water pipe, water continues to flow out of the detection pipe, so that the water leakage can be detected by the sensor.

  The present invention can be implemented in various forms other than the above. For example, it is realizable with forms, such as a water leak detection method of a water pipe.

The conceptual diagram of the water leak detection apparatus in 1st Embodiment of this invention. The figure which shows the mode of the water leak detection apparatus when there is no water leak in a water pipe. The figure which shows the mode of the water leak detection apparatus when there is water leak in a water pipe. The conceptual diagram of the water leak detection apparatus in 2nd Embodiment. The figure which shows the mode of the water leak detection apparatus when there is no water leak in a water pipe. The figure which shows the mode of the water leak detection apparatus when there is water leak in a water pipe. The conceptual diagram of the water leak detection apparatus in 3rd Embodiment. The figure which shows the mode of the water leak detection apparatus when there is no water leak in a water pipe. The figure which shows the mode of the water leak detection apparatus when there is water leak in a water pipe.

First embodiment:
FIG. 1 is a conceptual diagram of a water leak detection device 500 for a water pipe 110 in the first embodiment of the present invention. For convenience of illustration, water in the water pipe 110 and the water leakage detection device 500 is indicated by hatching. In the water pipe 110, a part of the water pipe 110 including its end is installed in the indoor R on the ground, and the remaining part is installed in the underground G and passes through the basement B. A faucet 300 is provided at the end of the water pipe 110 installed in the indoor R on the ground. A first shut valve 210 is provided in the water pipe 110 in the basement B, and a water leak detection device 500 is installed downstream of the first shut valve 210.

  The water leakage detection device 500 includes a detection pipe 120, a second shut valve 220 provided in the detection pipe 120, a flow sensor 230, and a control device 400. The detection pipe 120 is installed in the water pipe 110 on the downstream side of the first shut valve 210. One end 121 of the detection pipe 120 is attached to the water pipe 110 and communicates with the water pipe 110. The other end 122 of the detection pipe 120 is located vertically below the water pipe 110. However, the other end 122 of the detection pipe 120 may be installed at an arbitrary position as long as it is below the water pipe 110. The downstream part including the other end 122 of the detection pipe 120 is provided to be narrower than the upstream part including the one end 121. The downstream portion including the other end 122 of the detection pipe 120 has, for example, an inner diameter of 10 mm or less and a length in the range of 50 to 70 cm.

  The flow sensor 230 is provided in the detection pipe 120 and is located on the upstream side of the second shut valve 220. The flow sensor 230 measures the flow rate of water in the detection pipe 120 and transmits the measured flow value to the control device 400. Specifically, the flow rate sensor 230 transmits the flow rate value of water to the control device 400 when water flows out from the other end 122 of the detection pipe 120, and the flow rate when there is no water flow out. No signal is transmitted to the control device 400. In the first embodiment, the flow sensor 230 is used as a sensor that detects the presence or absence of water outflow from the detection pipe 120.

  The control device 400 is constituted by a microcomputer including a central processing unit and a main storage device. The control device 400 operates the first shut valve 210, the second shut valve 220, and the alarm device 600 installed in the indoor R on the ground. Control. Moreover, the control apparatus 400 determines the presence or absence of the water leak of the water pipe 110 using the detection value of the flow sensor 230. FIG. For convenience of illustration, connection relationships for control signals and sensor signals between the control device 400 and the above-described devices are indicated by broken lines.

  In FIG. 1, the first shut valve 210 provided in the water pipe 110 is open, and the second shut valve 220 provided in the detection pipe 120 is closed. At this time, the entire water pipe 110 and the detection pipe 120 upstream of the second shut valve 220 are filled with water.

  FIG. 2 is a view showing a state after the first shut valve 210 of the water pipe 110 is closed and the second shut valve 220 of the detection pipe 120 is opened, and a water leak detection device when there is no water leak in the water pipe 110. 500 is shown. When the first shut valve 210 of the water pipe 110 is closed, water and water pressure on the upstream side of the first shut valve 210 are shut off. And if the 2nd shut valve 220 of the detection pipe 120 is opened, the water in the detection pipe 120 will receive atmospheric pressure. When the second shut valve 220 is opened, the water in the detection pipe 120 tends to flow to the other end 122 due to gravity. Here, the inner diameter of the other end 122 of the detection pipe 120 is set so thin that air does not enter the detection pipe 120 due to the surface tension of the water surface located at the other end 122. For this reason, the water in the detection pipe 120 slightly drops after passing through the second shut valve 220 and stops before the opening of the other end 122.

In some cases, the water in the detection pipe 120 descends and the water is exposed to the outside through the opening of the other end 122. In this case, when the mass of the water in the exposed part is M [kg], the surface tension of the water in the exposed part is γ [N / m], and the acceleration of gravity is g [m / s ² ], The inner diameter D [m] of the end 122 is preferably set so as to satisfy the following expression (1).
π × γ × D ≧ M × g (1)

  Setting the inner diameter of the other end 122 of the detection pipe 120 to be narrow is that the first shut valve 210 is closed and the second shut valve 220 is opened when the water pipe 110 has no water leakage. 3 is an example of outflow prevention means for preventing outflow of water from the detection pipe 120. FIG. However, the water leakage detection device 500 may not include the outflow prevention means. In the detection pipe 120, negative pressure (pressure smaller than atmospheric pressure) is generated as a result of the water in the detection pipe 120 flowing in the direction of gravity.

  When there is no water leakage in the water pipe 110 shown in FIG. 2, gravity, atmospheric pressure, and negative pressure applied to the water in the detection pipe 120 are balanced, and no water flows out of the detection pipe 120. Therefore, the flow sensor 230 transmits a signal indicating no flow rate to the control device 400. When the flow sensor 230 detects that there is no outflow of water, the control device 400 determines that there is no water leakage in the water pipe 110. Immediately after opening the second shut valve 220, the water in the detection pipe 120 slightly falls, so that the control device 400 has a flow rate after a certain time (for example, 5 seconds) after the second shut valve 220 is opened. It is preferable to acquire the flow rate value measured by the sensor 230.

  FIG. 3 is a diagram illustrating a state of the water leak detection device 500 when water leaks in the water pipe 110 in the state of FIG. The water leak hole LH is located downstream of the first shut valve 210 of the water pipe 110. When water leaks in the water pipe 110, the atmospheric pressure applied to the water surface located in the water leak hole LH breaks the equilibrium in FIG. 2, and water flows out from the other end 122 of the detection pipe 120. Accordingly, the flow sensor 230 transmits the flow value of water in the detection pipe 120 to the control device 400. When the flow rate sensor 230 detects that the water has flowed out, the control device 400 determines that there is water leakage in the water pipe 110 downstream from the first shut valve 210. Further, when it is determined that there is water leakage in the water pipe 110, the control device 400 may continue to close the first shut valve 210. At the same time, the alarm device 600 installed in the indoor R on the ground may issue an alarm.

  As described above, in the first embodiment, the control device 400 detects that the water flow sensor 230 has an outflow of water while the first shut valve 210 is closed and the second shut valve 220 is open. In this case, it is determined that there is water leakage in the water pipe 110 downstream of the first shut valve 210. That is, when water leaks in the water pipe 110, water flows out from the detection pipe 120, so that water leak in the water pipe 110 can be detected with a simple configuration.

Second embodiment:
FIG. 4 is a conceptual diagram of a water leakage detection device 500a in the second embodiment, and corresponds to FIG. 1 of the first embodiment. Compared with the first embodiment shown in FIG. 1, the configuration of the detection pipe 120a is different and the container 240 with the water level sensor 250 is provided without the flow rate sensor 230, and other configurations are substantially the same. .

  In FIG. 4, the detection pipe 120 a is provided so that the downstream portion including the other end portion 122 has the same thickness as the upstream portion including the one end portion 121. The other end 122 of the detection pipe 120a is thicker than the first embodiment so that water flows out from the other end 122 when the second shut valve 220 is opened. At a position below the other end 122 of the detection pipe 120a, a container 240 that stores water flowing out from the detection pipe 120a is installed. The opening K1 of the container 240 is located above the opening K2 of the other end 122 of the detection pipe 120a. For this reason, the container 240 can accommodate water up to a water level higher than the height of the opening K2 of the other end 122 of the detection pipe 120a. The container 240 is an outflow prevention means for preventing outflow of water from the detection pipe 120a when the first shut valve 210 is closed and the second shut valve 220 is opened when there is no water leakage in the water pipe 110. It is another example.

  A water level sensor 250 is provided on the periphery of the opening 240 of the container 240. The water level sensor 250 is preferably installed at a position higher than the opening K2 of the other end 122 of the detection pipe 120a. In the example of FIG. 4, the water level sensor 250 measures the water level at the position of the opening K <b> 1 of the container 240 and transmits the measured water level value to the control device 400. Specifically, when the water level in the container 240 reaches the opening K1, the water level sensor 250 transmits a signal indicating the maximum water level value to the control device 400. Further, when the water level in the container 240 does not reach the opening K1, the water level sensor 250 transmits a signal indicating a water level value of zero to the control device 400. In the second embodiment, the water level sensor 250 is used as a sensor that detects the presence or absence of water outflow from the detection pipe 120.

  FIG. 5 corresponds to FIG. 2 of the first embodiment, and shows a state of the water leakage detection device 500a when there is no water leakage in the water pipe 110. FIG. When the second shut valve 220 of the detection pipe 120a is opened, the water in the detection pipe 120a flows into the container 240. When the water surface in the container 240 reaches the opening K2 of the other end 122 of the detection pipe 120a, the outflow of water stops. At this time, the gravity applied to the water in the detection pipe 120a, the atmospheric pressure applied to the water surface in the container 240, and the negative pressure generated from the outflow of water in the detection pipe 120a are balanced. Since the opening K1 of the container 240 is located above the opening K2 of the other end 122 of the detection pipe 120a, the water level in the container 240 when the outflow of water from the detection pipe 120a reaches the water level sensor 250. do not do.

  When there is no water leakage in the water pipe 110 shown in FIG. 5, the water level in the container 240 has not reached the opening K <b> 1, so the water level sensor 250 transmits a signal indicating the water level value zero to the control device 400. The control device 400 regards the signal indicating the water level value zero transmitted from the water level sensor 250 as a signal indicating that there is no outflow of water from the detection pipe 120a, and determines that there is no water leakage in the water pipe 110.

  FIG. 6 is a diagram illustrating a state of the water leak detection device 500a when water leaks in the water pipe 110 in the state of FIG. 5, and corresponds to FIG. 3 of the first embodiment. When water leaks in the water pipe 110, the atmospheric pressure applied to the water surface located in the water leak hole LH breaks the equilibrium in FIG. 5, and water flows out from the detection pipe 120a again. The water that has flowed out fills the container 240, and the water surface reaches the opening K <b> 1 of the container 240. Therefore, the water level sensor 250 transmits a signal indicating the maximum water level value to the control device 400. The control device 400 regards the signal indicating the maximum water level value transmitted from the water level sensor 250 as a signal indicating that there is an outflow of water from the detection pipe 120a, and supplies the signal to the water pipe 110 downstream of the first shut valve 210. Determine that there is water leakage.

  In the second embodiment, when the first shut valve 210 is closed and the second shut valve 220 is opened, the control device 400 detects that the water level value in the container 240 is maximum. It is determined that there is water leakage in the water pipe 110 downstream of the first shut valve 210. That is, when water leaks in the water pipe 110, water flows out from the detection pipe 120a again, so that the water leak in the water pipe 110 can be detected with a simple configuration. Instead of the water level sensor 250, a flow rate sensor may be provided in the detection pipe 120a.

Third embodiment:
FIG. 7 is a conceptual diagram of a water leakage detection device 500b according to the third embodiment, and corresponds to FIG. 1 of the first embodiment. Compared with the first embodiment shown in FIG. 1, the length of the detection pipe 120b and the point where the pressure reducing pump 280 is provided are different, and other configurations are substantially the same.

  In FIG. 7, the detection pipe 120b is shorter than the detection pipe 120 shown in FIG. The decompression pump 280 is installed in the water pipe 110 on the downstream side of the first shut valve 210 of the water pipe 110 via the connection pipe 260. The decompression pump 280 has a function of reducing the pressure in the water pipe 110. The decompression pump 280 is an outflow prevention means for preventing outflow of water from the detection pipe 120b in a state where the first shut valve 210 is closed and the second shut valve 220 is opened when there is no water leakage in the water pipe 110. Another example. The connection pipe 260 is provided with a third shut valve 270. The operations of the decompression pump 280 and the third shut valve 270 are controlled by the control device 400.

  In FIG. 7, the first shut valve 210 provided in the water pipe 110 is open, the second shut valve 220 provided in the detection pipe 120b and the third shut valve 270 provided in the connection pipe 260 are closed. Yes. At this time, the entire water pipe 110, the detection pipe 120b upstream of the second shut valve 220, and the connection pipe 260 upstream of the third shut valve 270 are filled with water.

  FIG. 8 is a view showing a state after the first shut valve 210 is closed and the second shut valve 220 and the third shut valve 270 are opened in the state of FIG. 7, and the water pipe 110 has no water leakage. The state of the water leakage detection device 500b is shown. The control device 400 reduces the pressure in the connection pipe 260c between the third shut-off valve 270 and the pressure-reducing pump 280 with the three shut-off valves 210, 220, and 270 closed before the state shown in FIG. Reduced by pump 280 to create negative pressure. Thereafter, when the decompression pump 280 is stopped and the third shut valve 270 is opened, the state shown in FIG. 8 is obtained. At this time, the gravity applied to the water in the detection pipe 120b, the atmospheric pressure applied to the water surface located at the other end 122 of the detection pipe 120b, and the negative pressure generated by the decompression pump 280 are balanced, and the detection pipe There is no outflow of water from 120b.

  FIG. 9 is a diagram illustrating a state of the water leak detection device 500b when water leaks in the water pipe 110 in the state of FIG. 8, and corresponds to FIG. 3 of the first embodiment. When water leaks in the water pipe 110, the atmospheric pressure applied to the water surface located in the water leak hole LH breaks the equilibrium in FIG. 8, and water flows out from the other end 122 of the detection pipe 120b. Also in the third embodiment, when the flow sensor 230 detects that the first shut valve 210 is closed and the second shut valve 220 is open, the flow sensor 230 detects that the water has flowed out. It can be determined that there is water leakage in the water pipe 110 downstream of the 1-shut valve 210.

  The present invention is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments corresponding to the technical features in each embodiment described in the summary section of the invention are intended to solve part or all of the above-described problems, or one of the above-described effects. In order to achieve part or all, replacement or combination can be appropriately performed. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

110 ... Water pipe 120, 120a, 120b ... Detection pipe 121 ... One end 122 ... Other end 210 ... First shut valve 220 ... Second shut valve 230 ... Flow sensor 240 ... Vessel 250 ... Water level sensor 260, 260c ... Connection pipe 270 ... third shut valve 280 ... pressure reduction pump 300 ... faucet 400 ... control device 500, 500a, 500b ... water leakage detection device 600 ... alarm device B ... basement G ... basement K1 ... opening K2 ... opening LH ... water leakage hole R ... indoor

Claims (6)

A water leak detection device for water pipes,
A detection pipe installed in the water pipe downstream from the first shut valve provided in the water pipe, one end communicating with the water pipe and the other end positioned below the water pipe;
A second shut valve provided in the detection pipe;
A sensor for detecting the presence or absence of water outflow from the detection pipe;
A control device for determining the presence or absence of water leakage in the water pipe using the detection value of the sensor;
With
When the sensor detects that the water has flowed out with the first shut valve closed and the second shut valve open, the control device may be located downstream of the first shut valve. It is determined that there is water leakage in the water pipe.
Water leak detection device. The water leakage detection device according to claim 1, further comprising:
An outflow prevention means for preventing outflow of water from the detection pipe in a state where the first shut valve is closed and the second shut valve is open when there is no water leakage in the water pipe;
Water leak detection device. In the water leak detection device according to claim 2,
The outflow prevention means has an inner diameter of the other end portion of the detection pipe such that air does not enter the detection pipe due to a surface tension of a water surface located at the other end portion with the second shut valve open. Including thin settings,
Water leak detection device. In the water leak detection device according to claim 3,
When water is exposed to the outside from the opening at the other end of the detection pipe, the mass of water in the exposed portion is M [kg], and the surface tension of water in the exposed portion is γ [N / m ], And when the gravitational acceleration is g [m / s ² ], the inner diameter D [m] of the other end is set so as to satisfy the following formula π × γ × D ≧ M × g. ,
Water leak detection device. In the water leak detection device according to claim 2,
The outflow prevention means is installed at a position below the other end of the detection pipe, and includes a container for storing water flowing out from the detection pipe,
The container is configured to be capable of containing water up to a water level equal to or higher than the height of the opening at the other end of the detection pipe.
Water leak detection device. In the water leak detection device according to claim 2,
The outflow prevention means includes a pressure reducing pump that is installed in the water pipe downstream from the first shut valve and reduces the pressure in the water pipe.
Water leak detection device.

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