KR20200024569A - Apparatus to detect water leak by using piezoelectric film - Google Patents

Abstract

A water leakage sensing apparatus using a piezoelectric film according to an embodiment of the present invention includes: a plurality of piezoelectric films attached in the circumferential direction from the outer surface of a water pipe which can leak water; and a water leakage sensing unit which detects water leakage by detecting a vibration mode generated from at least one piezoelectric film among the plurality of piezoelectric films when the water leakage occurs. With this configuration, when the water leakage occurs in a pipe such as the water pipe, it is possible to accurately sense the vibration mode generated in the pipe using the plurality of piezoelectric films. Accordingly, it is possible to accurately detect the water leakage regardless of where the water leakage is occured.

Description

Leakage detection device using piezoelectric film {APPARATUS TO DETECT WATER LEAK BY USING PIEZOELECTRIC FILM}

The present invention relates to a leak detection device using a piezoelectric film, and more particularly, to accurately detect a vibration mode generated by a plurality of piezoelectric films using a plurality of piezoelectric films when a leak occurs in a pipe such as a water pipe. The present invention relates to a leak detection apparatus using a piezoelectric film.

Currently, in Korea, due to poor construction or deterioration of water supply pipes or sewage pipes, for example, a considerable amount of water leakage occurs in water supply pipes.

In particular, leakage of water pipes is not just a matter of cost, but a problem related to public welfare in that drought can cause water shortages.

In addition, when a leak occurs in the water pipe, not only waste of money but also foreign matter, bacteria, heavy metals, etc. are introduced into the water pipe due to the pressure change at the location of the leak, thereby causing water pollution.

Therefore, it is necessary to replace and repair old or damaged water pipes by accurately identifying the leak location of water pipes, and conventional leak detection technology has a limitation in detecting a small amount of water leak. There was a limit not easy to do.

For example, with a conventional leak detection device, a designed sensor is attached to a tube so that moisture can directly penetrate the sensor. However, in the case of such a device, there is a risk of malfunction if the surrounding water in the place where the pipe is buried, not the water due to leakage.

In addition, as a study on the existing leak detection device, there was a study to detect the leak point by calculating the time difference of the leak sound using the acoustic emission sensor or the vibration acceleration sensor. However, in this case, it is appropriate when a large noise is generated, but there is a limit that is disadvantageous for detection when a low frequency noise of a small size is generated.

Therefore, there is a need for the development of a leak detection device that accurately detects a leak in a pipe regardless of a leak location.

Related prior art is Korean Patent No. 10-1298896 (name of the invention: clamp-type leak detection device, registration date: August 10, 2013).

Embodiments of the present invention can accurately detect the vibration mode generated in the pipe by using a plurality of piezoelectric film when the leak occurs in the pipe, such as a water pipe, through which the piezoelectric, which can accurately detect the leak regardless of the location of the leak Provided is a leak detection device using a film.

The problem to be solved by the present invention is not limited to the above-mentioned task (s), another task (s) not mentioned will be clearly understood by those skilled in the art from the following description.

Leakage detection apparatus using a piezoelectric film according to an embodiment of the present invention, when the leakage occurs when a plurality of piezoelectric film and circumferentially attached to the outer surface of the water pipe capable of leaking, generated from at least one piezoelectric film of the plurality of piezoelectric film It includes a leak detection unit for detecting the leak by detecting the vibration mode, by this configuration, it is possible to accurately detect the vibration mode generated in the pipe by using a plurality of piezoelectric film when the leak occurs in the pipe, such as water pipes, This enables accurate leak detection regardless of the location of the leak.

In addition, the plurality of piezoelectric films according to the embodiment of the present invention are arranged in at least two rows along the longitudinal direction of the water pipes on the outer surface of the water pipes and are formed of a first piezoelectric film row and a second piezoelectric film row, respectively, The plurality of piezoelectric films forming the piezoelectric film array may be arranged at regular intervals in the circumferential direction on the outer surface of the water pipe.

In addition, the plurality of piezoelectric films forming the first piezoelectric film string or the second piezoelectric film string according to the embodiment of the present invention may be disposed at intervals of 90 degrees in the circumferential direction on the outer surface of the water pipe.

In addition, a total of four piezoelectric films forming the first piezoelectric film array according to an embodiment of the present invention are attached at positions of 0 degrees, 90 degrees, 180 degrees, and 270 degrees from the reference position of the water pipe, and the second piezoelectric film. A total of four piezoelectric films forming a film row may be attached at positions 45 degrees, 135 degrees, 225 degrees, and 315 degrees from the reference position of the water pipe.

In addition, the vibration mode generated by the piezoelectric film according to an embodiment of the present invention, the zero-order vibration mode that is contracted or relaxed in the radial direction of the water pipe, and the one end is fixed and the other end is provided with a free cantilever type It may be a primary vibration mode of bending vibration in the vertical direction in the water pipe.

In addition, the leak detection unit according to an embodiment of the present invention, in order to detect the zero-order vibration mode of the water pipe due to the leak, a plurality of the piezoelectric film and the second piezoelectric film forming the first piezoelectric film string It may be determined whether the signal magnitudes of the plurality of piezoelectric films forming a column are the same.

In addition, the leak detection unit according to an embodiment of the present invention, in order to detect the primary vibration mode of the water pipe due to leakage, a pair of piezoelectric films facing each other among the plurality of piezoelectric films forming the piezoelectric film train It is possible to detect whether or not a difference in the signal magnitude of the pair of piezoelectric films and the other.

In addition, the leak detection unit according to an embodiment of the present invention, a signal amplifier for amplifying the signals received from the plurality of piezoelectric film, an oscilloscope for converting the signal received from the signal amplifier to the vibration signal information, and the vibration of the oscilloscope It may include a signal analyzer for analyzing signal information and a warning sound generator for generating a warning sound when determined as the vibration mode as a result of the analysis of the signal analyzer.

In addition, an aluminum electrode corresponding to the shape of the piezoelectric film may be attached to upper and lower surfaces of the piezoelectric film according to an embodiment of the present invention, and a wire connected to the leak detection unit may be connected to the plus and minus electrodes of the aluminum electrode. .

According to an embodiment of the present invention, when a leak occurs in a pipe such as a water pipe, a vibration mode generated in the pipe may be accurately detected using a plurality of piezoelectric films, and thus, the leak may be accurately detected regardless of the leak position. .

1 is a perspective view showing a state in which a water leak detection apparatus according to an embodiment of the present invention is mounted on a water pipe.
FIG. 2 is a perspective view of the piezoelectric film shown in FIG. 1.
3 is a vibration mode generated when leakage occurs, (a) represents the zero-order vibration mode, (b) represents the primary vibration mode.
(A) is a figure corresponding to FIG. 1, (b) is the A cross section of (a), (c) is the B cross section of (a).
FIG. 5A is a view corresponding to FIG. 1, (b) is a C cross section and a D cross section of (a) in the 0th order mode, and (c) is a C cross section and D of (a) in the primary mode Section.
FIG. 6 is a schematic configuration diagram of the leak detector illustrated in FIG. 1.

Advantages and / or features of the present invention and methods for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

1 is a perspective view illustrating a state in which a leak detection apparatus according to an embodiment of the present invention is mounted on a water pipe, and FIG. 2 is a perspective view of the piezoelectric film illustrated in FIG. 1. 3 is a vibration mode generated when leakage occurs, (a) represents the zero-order vibration mode, (b) represents the primary vibration mode.

First, referring to FIG. 1, the leak detecting apparatus 100 using the piezoelectric film according to an exemplary embodiment of the present invention detects a vibration mode of the water pipe 1 when a leak occurs, and accurately detects a leak position. It may include a plurality of piezoelectric film 111 attached in the circumferential direction on the outer surface of the water pipe (1) possible, and a leak detection unit 130 for detecting a leak by detecting the vibration mode generated from the plurality of piezoelectric film 111 Can be.

With this configuration, when a leak occurs in the water pipe 1, it is possible to accurately detect the vibration mode of the water pipe 1 to accurately find the leak point regardless of the leak position.

Looking at each configuration, the piezoelectric film 111 of the present embodiment, when the leakage occurs in the water pipe (1) detects the vibration mode and vibrates by the vibration mode of the water pipe (1) to generate an electrical signal. That is, the vibration of the water pipe 1 is converted to the vibration of the piezoelectric film 111, the vibration of the piezoelectric film 111 is converted into an electrical signal that can be analyzed by the leak detector 130.

As illustrated in FIG. 2, the piezoelectric film 111 includes a thin piezoelectric film layer 112 and a pair of aluminum electrodes 113 covering upper and lower surfaces of the piezoelectric film layer 112. One of the aluminum electrodes 113 has a positive (+) electrode and the other has a negative (-) electrode.

Since the piezoelectric film 111 has flexibility in itself, as shown in FIG. 1, the piezoelectric film 111 may be attached to the outer surface of the water pipe 1 in a pinched state.

On the other hand, referring to Figure 1, a plurality of piezoelectric film 111 according to an embodiment of the present invention, a total of eight is provided, four of the piezoelectric film 111 of the first piezoelectric film row 110 The remaining four piezoelectric films form a second piezoelectric film array 120 spaced apart from the first piezoelectric film array 110.

However, the arrangement and structure of the piezoelectric film 111 is not limited thereto. It is obvious that fewer or more piezoelectric films can be arranged in a plurality of rows, as well as having only one row of arrangement structures.

In the present embodiment, the first piezoelectric film array 110, as shown in Figure 1, a total of four piezoelectric film 111 may be arranged at intervals of 90 degrees in the circumferential direction on the outer surface of the water pipe (1). . In other words, a total of four piezoelectric films 111 constituting the first piezoelectric film array 110 are 0 degrees, 90 degrees, 180 degrees, at the reference position of the water pipe 1, as shown in FIG. It may be attached at a position (# 1-4) of 270 degrees.

The piezoelectric films 111 of the second piezoelectric film array 120 have a structure that is alternated with the piezoelectric films 111 of the first piezoelectric film array 110. In other words, the piezoelectric films 111 of the second piezoelectric film rows 120 are also spaced apart from each other along the circumferential direction on the outer surface of the water pipe 1, but are alternately arranged with the piezoelectric films 111 of the first piezoelectric film rows 110. It may be attached at positions # 1'-4 'at 45 degrees, 135 degrees, 225 degrees, and 315 degrees from the reference position.

As such, the first piezoelectric film row 110 and the second piezoelectric film row 120 are disposed in the water pipe 1 in a state spaced apart from each other, and the piezoelectric films 111 of the respective film rows 110 and 120 are staggered. By having a state, the vibration mode can be detected accurately, which can pinpoint leaks.

In other words, it is preferable that the first piezoelectric film rows 110 and the second piezoelectric film rows 120 have a spacing of 3 to 5 mm. However, the present invention is not limited thereto and may have different intervals.

In addition, although the piezoelectric films 111 of the first piezoelectric film array 110 and the piezoelectric films 121 of the second piezoelectric film array 120 have a structure in which they cross each other, the present invention is not limited thereto. Naturally, it may have a batch structure and the like.

Meanwhile, referring to the vibration mode, as shown in FIG. 3, there are two vibration modes as vibration modes generated when leakage occurs in the water pipe 1. First, the zeroth order vibration mode of the vibration mode is a vibration mode when the water pipe 1 contracts or relaxes in the radial direction due to the occurrence of leakage as shown in FIG.

Referring to FIG. 3B, the first vibration mode in the vibration mode is a mode in which the water pipe 1 is bent and vibrated in the up and down direction by providing a cantilever type having one side fixed and the other free.

As such, when leakage occurs, a zero-order or first-order vibration mode may be generated in the water pipe 1, which may include a first piezoelectric film row 110 and a second piezoelectric film row formed of a plurality of piezoelectric films 111. 120) can accurately find the vibration mode.

In other words, by comparing or contrasting the signal information in the first piezoelectric film string 110 and the signal information in the second piezoelectric film string 120, it is possible to more accurately identify a leak position.

Hereinafter, with reference to the drawings, a method of sensing the vibration mode of the leak detection apparatus 100 according to an embodiment of the present invention will be described.

(A) is a figure corresponding to FIG. 1, (b) is the A cross section of (a), (c) is the B cross section of (a).

When a leak occurs in the water pipe 1, a method of detecting a zero-order vibration mode of the water pipe 1 due to the leak may include the piezoelectric film of the first piezoelectric film row 110 shown in FIG. It may be determined by comparing the signal sizes of the 111 and the signal sizes of the piezoelectric films 111 of the second piezoelectric film array 120 shown in FIG. 4C. For example, if all of the piezoelectric films 111 of the first piezoelectric film array 110 installed on the A cross section of the water pipe 1 have the same signal amplitude, the vibration generated in the radial direction of the leak-producing dead water pipe 1 is the same. This can be seen in the 0th order vibration mode.

Here, as the distance between the first piezoelectric film row 110 and the second piezoelectric film row 120 provided in the water pipe 1 increases, the zero-order vibration mode may be detected more accurately. For example, if the position where the first piezoelectric film row 110 is leaked is close, the portion where the second piezoelectric film row 120 is installed is not likely, so the first piezoelectric film row 110 and the second piezoelectric film The comparison of vibration magnitudes in column 120 can be made more pronounced.

Meanwhile, as a method of detecting the first vibration mode of the water pipe 1 due to leakage, the piezoelectric films 111, # 1, and # 3 of the upper and lower parts of the piezoelectric films 111 of the first piezoelectric film array 110 may be used. And the signal sizes of the left and right piezoelectric films 111, # 2, and # 4 can be determined. In other words, when the signal size of the upper and lower piezoelectric films 111 is larger or smaller than the signal sizes of the left and right piezoelectric films 111, that is, when there is a difference in signal size, the first vibration mode may be identified.

When grasping the primary vibration mode, it is more preferable that the interval between the first piezoelectric film row 110 and the second piezoelectric film row 120 is closer. This is because the pair of piezoelectric films 111, # 1 ′, and # 3 ′ facing each other also in the second piezoelectric film string 120 and the other pair of piezoelectric films 111, # 2 ′, # 4 ′ By grasping the signal magnitude and comprehensively grasping the grasped information with the information with the first piezoelectric film string 110, it is possible to accurately grasp the primary vibration mode.

On the other hand, with reference to Figure 5 will be described with respect to the generation of the vibration mode in the longitudinal section of the water pipe (1) and through this will be described a method for detecting the leak.

(A) is a figure corresponding to FIG. 1, (b) is a C cross section and a D cross section of (a) in 0th mode, (c) is a C cross section and D of (a) in primary mode, Section.

Referring to FIG. 5B, in the zeroth order vibration mode, vibrations in the C cross section and the D cross section are the same. Here, when one piezoelectric film row, for example, the second piezoelectric film row 120 is installed in the vicinity of the leak point, and the other piezoelectric film row 110 is installed at a point away from the leak point, a signal is generated. Because of different sizes, leaks can be detected.

Referring to FIG. 5C, in the first vibration mode, it may be confirmed that vibrations are generated up and down on the C cross-section, but vibrations of the left and right are not generated on the D cross-section. In other words, when the vibration magnitude is maximum in the C cross section, the vibration magnitude is close to zero in the D cross section.

In this case, if the two piezoelectric film trains (110, 120) are installed in a position close to the leak point, the signal becomes more clear, so that accurate leak detection can be performed.

Meanwhile, referring to FIG. 1, signals obtained by the piezoelectric films 111 constituting each of the piezoelectric film strings 110 and 120 are transferred to the leak detector 130. As shown in FIG. 6, the leak detector 130 according to the present exemplary embodiment includes a signal amplifier 131 for amplifying signals received from a plurality of piezoelectric films 111 and vibration signal information for signals received from the signal amplifier 131. The oscilloscope 133 for converting the oscilloscope 133, the signal analyzer 135 for analyzing the vibration signal information of the oscilloscope 133, and the warning sound generator 137 for generating a warning sound when it is determined that the vibration mode is the analysis result of the signal analyzer 135. It may include.

Through this, when the leak occurs in the water pipe (1) can be provided in real time the information about the degree and point of the leak.

As such, according to an embodiment of the present invention, when a leak occurs in a pipe such as the water pipe 1, a vibration mode generated in the pipe may be accurately detected using a plurality of piezoelectric films, thereby irrespective of the leak position. It has the advantage of detecting leaks accurately.

Although specific embodiments of the present invention have been described so far, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

1: water pipe
100: leak detection device
110: first piezoelectric film heat
111: piezoelectric film
120: second piezoelectric film heat
130: leak detection unit

Claims (9)

A plurality of piezoelectric films attached in the circumferential direction on the outer surface of the leaky water pipe; And
A leak detection unit for detecting a leak by detecting a vibration mode generated from at least one piezoelectric film of the plurality of piezoelectric films when a leak occurs;
Leakage detection apparatus using a piezoelectric film comprising a.
The method of claim 1,
The plurality of piezoelectric films may be arranged in at least two rows along a length direction of the water pipe on the outer surface of the water pipe and formed of a first piezoelectric film row and a second piezoelectric film row. Piezoelectric film is leak detection device using a piezoelectric film, characterized in that arranged at regular intervals in the circumferential direction on the outer surface of the water pipe.
The method of claim 2,
The plurality of piezoelectric films forming the first piezoelectric film string or the second piezoelectric film string are disposed at 90 degree intervals in the circumferential direction on the outer surface of the water pipe.
The method of claim 3,
A total of four piezoelectric films forming the first piezoelectric film array are attached at positions of 0 degrees, 90, 180 degrees, and 270 degrees from the reference position of the water pipe.
A total of four piezoelectric films forming the second piezoelectric film array are attached at positions of 45 degrees, 135 degrees, 225 degrees, and 315 degrees from the reference position of the water pipe.
The method of claim 4, wherein
The vibration mode generated by the piezoelectric film,
Using a piezoelectric film, characterized in that the first order vibration mode to be bent in the vertical direction in the water pipe is provided in a zero-order vibration mode that is contracted or relaxed in the radial direction of the water pipe is fixed and the other end free cantilever Leak detection device.
The method of claim 5,
The leak detector may include a plurality of the piezoelectric films forming the first piezoelectric film row and the plurality of piezoelectric films forming the second piezoelectric film row to detect the zero-order vibration mode of the water pipe due to leakage. Leak detection apparatus using a piezoelectric film, characterized in that for determining whether the signal size is the same.
The method of claim 5,
The leak detector may detect a pair of piezoelectric films and a pair of piezoelectric films that face each other among a plurality of piezoelectric films forming the piezoelectric film array to detect a primary vibration mode of the water pipe due to leakage. Leakage detection device using a piezoelectric film, characterized in that for detecting the difference in size.
The method of claim 1,
The leak detection unit,
A signal amplifier for amplifying signals received from the plurality of piezoelectric films;
An oscilloscope for converting the signal received from the signal amplifier into vibration signal information;
A signal analyzer for analyzing the vibration signal information of the oscilloscope; And
Leakage detection device using a piezoelectric film, characterized in that it comprises a warning sound generator for generating a warning sound when determined as the vibration mode analysis result of the signal analyzer.
The method of claim 1,
An aluminum electrode corresponding to the shape of the piezoelectric film is attached to upper and lower surfaces of the piezoelectric film, and a wire connected to the leak detection unit is connected to a positive electrode and a negative electrode of the aluminum electrode. Device.

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