JP2016061763A - Water leakage spot detection method for water pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of indicating a piping route of a resin water pipe made of polyvinyl chloride or the like and detecting a water leakage spot on the line.SOLUTION: An ultrasonic pulse transmitter is attached to a base end side of piping, an ultrasonic pulse is transmitted from the base end side of the piping in the state where hydraulic pressure is applied into the piping as much as possible, the piping is filled with a pulse signal sound with Huygens' principle, a water leakage sound wave from the piping water leakage spot is detected by a sound wave detector on the ground and a water leakage spot is detected. A signal based on the ultrasonic pulse can be used for a detection pulse sound wave. It is preferred that line-tracing of the piping route is performed on the sound wave detector on the ground.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for detecting a water leakage point of a water pipe, particularly a resin water pipe.

  Leakage from water pipes in ordinary households and factories, or water leakage from water pipes laid on public roads is a major problem in terms of effective use of water resources. In other words, even if the amount of water leakage at each home or factory is small, the entire amount will be washed away without being used, and the leakage of water pipes laid on public roads will not be invalid. This is because the amount of collected water is dissipated as it is. For this reason, water leak detection of water pipes has been conventionally performed, and the detection method has been studied.

  A commonly used method for detecting water leaks in water pipes is to use a water leak detector (FIG. 4). A leak detector is used to listen to the leak sound indirectly from the ground, or the leak detector is applied to the water supply device to detect the leak point. However, the method using a water leak detector is difficult if the amount of water leak is not more than a certain level, and requires a certain number of years and experience. For this reason, various methods for detecting a water leakage location with higher accuracy are considered. For example, a method of detecting the sound wave of a water leak point from the ground by the difference from the reference signal by exciting the water in the water pipe (Patent Document 1), sending a cable with a flow detector attached to the tip into the pipe body, A method for detecting (Patent Document 2), a method for pouring tracer water in which a rare gas is dissolved into a pipe body, and detecting a rare gas leaking to the ground surface (Patent Document 3) are proposed.

  However, at present, it cannot be said that work efficiency for detecting water leakage has necessarily improved due to the digitization of survey equipment and the improvement in accuracy of sensor equipment. This is because even with a method using an ultrasonic sensor or the like, the arrangement of pipes buried in the ground is complicated, and it is difficult to easily identify the location of water leakage due to various disturbances. is there. Moreover, there are metal pipes buried in the ground and non-metal pipes such as resin pipes, and non-metal pipes are less likely to transmit sound than metal pipes. Recently, non-metallic pipes that have been laid in ordinary households have been increasingly used. Therefore, it is actually very difficult to specify a water leak location even if a method of detecting vibration such as sound waves using a sensor or the like is used.

  Therefore, as a method for detecting the water leakage location, the detection capsule is sent from the base end side of the pipe, and the water supply device for the pipe is closed and water pressure or water distribution pipe hydraulic pressure is applied to the base end side of the pipe. A method (Patent Document 4) characterized in that a capsule is moved to a leaking point to detect the leaking point (Patent Document 4), a high-voltage direct current is passed through the liquid in the pipe, and a surface current flowing out from the leaking point with the leak is detected. A method (Patent Document 5) has been proposed.

JP 60-238733 A JP 56-111442 A JP-A-5-340837 JP 2001-21435 JP 2013-24849

However, the signal from the detection capsule is a point signal regardless of sound waves, radio waves, etc., and is not much different from the conventional water leakage exploration technology. It is difficult to specify the location accurately. On the other hand, the method of flowing a high-voltage direct current to the liquid in the pipe is dangerous to detect, and it is difficult to identify the location of the water leakage by detecting the direction of the surface current, which has both advantages and disadvantages.
Therefore, it is desired to provide a safe water leak detection method that shows a pipe route on the display even if the pipe route is branched on the way, and specifies a sound wave diffusion point on the line as a water leak point.

The present invention allows ultrasonic pulses to be filled even in pipes branched according to the Huygens principle by continuously sending ultrasonic pulses to tap water in underground water pipes at a speed of about 1500 m / s. As a result, it was found that the ultrasonic line of the piping can be displayed and the leakage point can be detected with the improvement in the capacity of the detector on the ground.
Install a pulse sound wave transmitter on the base end side of the pipe, send a pulse sound wave from the base end side of the pipe to the water in the pipe with water pressure applied in the pipe, fill the pipe with a pulse signal, and leak the water A leaking point detection method for a water pipe is characterized by detecting a leaking sound wave from the ground with a sonic detector on the ground and detecting the leaking point.

  According to the method of the present invention, the pipe subjected to water pressure can be filled with pulsed sound waves even in a pipe branched according to the Huygens principle, and the pulsed sound waves leak from the ground surface from the water leakage point. Is easy to detect. In addition, it is possible to fill the ultrasonic pulse in the pipe and detect the image of the pipe line on the display. Therefore, it is possible to specify the location where the sound wave is diffused as a water leak location.

  According to the present invention, the detection pulse sound wave may be an audible sound, but it is preferably based on an ultrasonic pulse having a high frequency. If necessary, it is preferable to use a signal in which an audible sound is superimposed. This is because by increasing the water pressure in the pipe, high-frequency sound is more likely to be emitted from the water leakage point to the ground surface.

  An object of the present invention is to make it possible to detect a leaking point even in a situation where the S / N ratio is poor by using a signal having a strong autocorrelation and a detection technique. The sonic detector 3 on the ground arranges many synthetic aperture microphones 33 (Rake reception / phase synthesis) in parallel to the sound collector 32 as reception probes, and performs focus tuning & tracking by focus search and signal synthesis reproduction. Optimum equalizer is installed in the sound detector 34, background noise elimination (adaptive elimination of distant tones and near sounds), multi-ch signal A / D conversion (hardware H / W reduction by time sharing, 1-chip microcomputer Built-in), multi-microphone signal synthesis (AMP + A / D + phase delay synthesis + D / A), auto tuning & auto signal processing, etc. Detect.

It is a top view which shows the attachment state to the water supply piping of a sound wave transmitter. It is AA sectional view taken on the line of FIG. 1A. It is a side view which shows the whole acoustic probe. It is a top view which shows the arrangement | positioning state of the receiving probe of the sound collector of a sound wave probe. It is a top view which shows the probe meter display connected to a sound wave probe. It is a schematic diagram which shows the water leak location exploration method of this invention. It is explanatory drawing which shows the outline | summary of the conventional water leak detection construction method.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
Remove the water meter from the water pipe and attach the sonic transmitter 1 to the PVC pipe 2. A transmitter probe 11 is built in the transmitter 1, and an ultrasonic pulse having a high frequency is transmitted by energization from a power source. The pipe 2 is filled with water, and water pressure is applied. A pulsed sound wave is transmitted from the proximal end side of the pipe into the water in the pipe in a state where an ultrasonic pulse having a high frequency is applied to tap water in the pipe from the probe 11. Thereby, even if the pipe is branched, the pulse signal is filled in the pipe by the Huygens principle.

  On the other hand, FIG. 2 shows a sound probe 3 in which a sound collector 32 is provided at the tip of a probe 31 and a receiving probe 33 is provided in parallel on the surface thereof. It has a sensitivity of 10 to 15 times or more. On the other hand, a detection meter 34 is provided at the upper end of the exploration rod, and a pipe line is displayed on the display 34a. Therefore, when the power switch 35 is turned on and the sound collection is advanced while alternately switching the expansion switch 36 for setting the sound collection sensitivity to the expansion mode and the reduction switch 37 for setting the sound collection sensitivity to the reduction mode, a pipe route is provided on the display. In addition, the location of water leakage is displayed on the piping route.

  FIG. 3 is an explanatory diagram during exploration of the piping route and the water leakage location, and it is assumed that the water pipe 2 is piped to the underground layer 42 below the concrete road 4 in which the wire mesh 41 is embedded. The water meter of this water pipe 2 is removed, the ultrasonic pulse transmitter 1 is attached, and the ultrasonic wave is continuously transmitted to the tap water with water pressure in the pipe at about 1500 m / s. On the other hand, when the ground surface in which the pipe is embedded is advanced while swinging the lower sound collector 32 of the receiving probe 3 to the left and right, the sound wave from the water pipe is displayed as a line on the display 34a. When a high frequency or high current is passed through the water pipe, a magnetic field is formed around it, and an induced current easily flows. When the wire mesh 41 is present, the induced current or magnetic field around the water pipe is disturbed and cannot be accurately detected. In the present invention, since an ultrasonic pulse is used, the wire mesh 41 above the pipe does not get in the way and the pipe route is easily displayed. And since an ultrasonic wave leaks from a water leak location and leaks to the ground, it can detect with the sound detector 2, and can detect a water leak location.

  The speed of sound in water is about 1500 m / s, and the speed of sound in a medium is similar to that of a resin such as soft polyethylene and natural rubber. Therefore, using sound waves does not hinder sound wave detection. And when a sound wave becomes a high frequency like an ultrasonic wave, and when the water pressure is applied to the tap water in piping, it will make it easier to detect the leak sound from a water leak location. Therefore, the present invention is particularly excellent in water leak detection in a resin pipe.

DESCRIPTION OF SYMBOLS 1 ... Sound wave transmitter 2 ... Water supply piping 3 ... Sound wave probe 32 ... Sound collector

Claims (3)

  A pulse sound wave transmitter is installed on the base end side of the water pipe, and with the water pressure applied to the tap water in the pipe, a pulse sound wave is transmitted from the base end side of the pipe to the tap water in the pipe, and a pulse signal is sent into the pipe. A method for detecting a leaking point of a water pipe, wherein the leaking wave is detected by detecting a sound wave leaking from the leaking point with a ground acoustic detector.  2. A water pipe leakage point detection method according to claim 1, wherein the detection pulse sound wave is a signal based on an ultrasonic pulse. The water pipe leakage point detection method according to claim 2, wherein the ground acoustic detector performs line tracing of the piping route.

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