JP3801761B2 - Gas leak detection system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas leak detection system that detects a gas leak from a piping system and identifies the leak location.
[0002]
[Prior art]
Conventionally, as a gas leakage detection system that detects gas leakage from piping and identifies the leakage location, for example, a sound detection sensor is arranged at two locations on the piping, and the leakage sound emitted from the leakage location is the sound detection sensor at the two locations. The one that identifies the leak location based on the time difference until it is detected by the sensor, the one that detects the leaked gas with the odor sensor, or the attenuation of the laser beam that is seen when the leaked gas is irradiated with laser light It is known to detect and detect.
[0003]
[Problems to be solved by the invention]
However, among the conventional gas leak detection systems described above, when a sound detection sensor is used, if the pipe is buried, the sound detection sensor must be mounted by digging up the ground to the buried position, which requires work. It took a lot of effort.
[0004]
In addition, what is detected using an odor sensor or what is detected using a laser is easy because it can be detected on the ground surface, but gas heavier than air such as LP gas leaks from the buried pipe. However, since the gas hardly appears on the ground surface, it has a problem that leakage cannot be detected. Furthermore, for equipment using laser equipment, the equipment is large and costly for system construction.
[0005]
The present invention has been proposed in view of the above, and it is an object of the present invention to provide a gas leak detection system that can easily construct a system at low cost and can detect LP gas leak from an embedded pipe on the ground surface. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a predetermined frequency band extracted from sound collection information obtained by collecting sound on the ground surface in a gas leak detection system for detecting gas leak from a piping system. The noise information is obtained from the collected sound information by comparing the collected sound information subjected to the above-mentioned filter processing and the pre-patterned noise information by pattern matching, by performing a predetermined weighting process on the information of the sound and removing noise. Noise detection means to determine the leakage sound information and the above leakage sound information, whether the leakage sound is exposed piping, buried piping or concealed piping, and also whether the piping is a rubber tube or a steel pipe A leakage sound determination means for comparing the leakage sound pattern information set in advance according to each situation by sound pressure to determine which piping system installation state corresponds to the leakage sound, and the leakage sound The location where the leaked sound is maximized from the multiple sets of information, and the location of the leak as the location of the piping system is specified. And means .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of a gas leak detection system according to the present invention. In the figure, a gas leak detection system 100 includes a filter processing means 1, a leak sound determination means 2, and a leak location specifying means 3. Each of these means 1, 2, and 3 includes a CPU, a ROM, a RAM, and the like. In the computer constructed as the center, the CPU is configured as a software function that is executed by the CPU according to a predetermined program in the ROM.
[0009]
The filter processing means 1 performs a predetermined weighting process on the sound collection data (sound collection information) obtained by collecting sounds on the ground surface using the microphone 11 to remove noise.
The leaked sound determination means 2 compares the collected sound data from which noise has been removed by the filtering process with noise data (noise information) that has been patterned in advance by pattern matching, and removes the noise data from the collected sound data. Leakage sound data (leakage sound information) is confirmed, and “Gas Leakage” is displayed on the screen 21 in response to the confirmation. Then, the leak location specifying means 3 sets the confirmed leak sound data and the sound collection position data (sound collection position information) corresponding to the leak sound data as one set, and the leak sound is generated from the plural sets of data (information). The maximum position is specified, and that position is output as a leak point in the piping system.
[0010]
Next, the filter processing means 1 will be described with reference to FIGS.
FIG. 2 is a flowchart showing a procedure executed by the filter processing means. In the filter processing means 1, as a previous step, for example, microphones 11 are sequentially set at the A position, B position,..., M position along the ground surface where the gas pipe is embedded, and sound collection / recording is performed. .
[0011]
In step S1, sound collection data obtained by collecting and recording with the microphone 11 is taken from the recording tape 12, and the process proceeds to the next step S2. The acquired sound collection data is associated with position data at the A position, B position,..., M position.
[0012]
In step S2, only the 0 to 60 KHz band, which is a frequency band in which leakage sound is always included, is extracted from the acquired sound collection data, and the other frequency bands are removed as noise, and the process proceeds to the next step S3.
[0013]
In step S3, the frequency band (0 to 60 KHz) of the collected sound data obtained by extraction is divided into N equal parts, and any of 0, ± 0.3, ± 0.6, ± 1.0, etc. A predetermined weighting process is performed by multiplying these coefficients, and a process of removing noise mixed in the 0 to 60 KHz band is performed (FIG. 3). This noise processing is performed by applying a neural network model.
[0014]
In step S4, it is determined whether or not processing has been performed for all of the N equal frequency bands. If processing has been performed N times, it is determined that processing has been performed for all of the frequency bands, and the following processing is performed. Proceeding to step S5, if the process is not performed N times, step S3 and step S4 are repeated.
[0015]
In step S5, noise is removed by performing the above extraction process and weighting process on all the collected sound collection data, and the process proceeds to the next step S6.
[0016]
In step S6, the collected sound data from which noise has been removed is stored in a predetermined memory area together with the position data, and the filtering process is completed.
[0017]
Next, the leakage sound determination means 2 will be described with reference to FIG.
FIG. 4 is a flowchart showing a procedure executed by the leaked sound determination means. In this leaked sound determination means 2, first, in step S11, the noise collection data after noise removal stored in a predetermined memory area is read, and the process proceeds to the next step S12.
[0018]
In step S12, the noise data that has been patterned and stored in advance is read, and the process proceeds to the next step S13.
[0019]
In step S13, the read sound collection data and the noise data are compared by a pattern matching method, and the process of removing the noise data from the sound collection data is performed to extract leaked sound data, and the process proceeds to the next step S14.
[0020]
In step S14, data generated by removing noise data from the collected sound data is determined as leaked sound data, and the process proceeds to next step S15. When the leaked sound data is confirmed, the screen 21 displays “gas leaked” and notifies the user.
[0021]
In step S15, the leaked sound corresponds to the exposed sound by comparing the determined leaked sound data with the pattern data of the exposed sound that is stored in advance and is leaked from the pipe exposed on the ground surface. If the leakage sound corresponds to the exposure sound, the process proceeds to the next step S18, and if the leakage sound does not correspond to the exposure sound, the process branches to step S16.
[0022]
In step S16, the leaked sound corresponds to the buried sound by comparing the confirmed leaked sound data with the pattern data of the buried sound that is stored in advance and is leaked from the underground pipe. If the leakage sound corresponds to the embedded sound, the process proceeds to the next step S18, and if the leakage sound does not correspond to the embedded sound, the process branches to step S17.
[0023]
In step S17, since the determined leaked sound data is neither an exposure sound nor a buried sound, it is assumed that the leaked sound data corresponds to a concealed sound that is a leaked sound from a pipe concealed in a building or the like. move on.
The pattern data in each of the above steps S15, S16, and S17 is set for each of the case where the pipe is a rubber pipe and the case where the pipe is a steel pipe. In each step S15, S16, and S17, the pattern data in both cases is set. Thus, the leakage sound can be determined with higher accuracy.
[0024]
In step S18, the leaked sound is assumed to be the sound (exposure sound, embedded sound, concealed sound) determined in steps S15, S16, and S17, and stored together with its position data. Complete.
[0025]
The comparison between the leaked sound data and the pattern data in the above steps S15, S16, and S17 is a comparison of sound pressures. As a result of this comparison, as described above, any of the pipe installation situations of exposure, burial, and concealment can be obtained. It is possible to determine whether the sound is a relevant sound, and it is also possible to estimate the hole diameter and the leakage amount at the leakage location from the piping installation status and the sound pressure data.
[0026]
In the above description, the leak sound data and the leak sound pattern data stored in advance are sequentially compared for all the leak sound pattern data. If there is, a configuration having a changeover switch function may be adopted so that pattern comparison is performed only for the leakage sound pattern data corresponding to the piping system installation status. Thus, by providing the changeover switch function, it is possible to determine the leaked sound more quickly.
[0027]
Next, the leakage location specifying means 3 will be described with reference to FIG.
At the stage where the leaked sound at each sound collection position (A position, B position,..., M position) has been determined, the location of the leak is specified as follows.
[0028]
FIG. 5 is an explanatory diagram for specifying a leakage location, FIG. 5A is an explanatory diagram when a piping diagram is present, and FIG. 5B is an explanatory diagram when a piping diagram is not present.
If there is a piping diagram, in the area where gas leakage is occurring, set the sound collection position (A position, B position,..., M position) along the piping diagram. The leakage sound is confirmed for Then, when the maximum value of the leaked sound determined at each sound collection position (A position, B position,..., M position) is sequentially plotted, for example, as shown in FIG. Therefore, the position P at which the maximum value is taken is specified as the leakage location.
[0029]
Alternatively, an arbitrary point can be set as a starting point, and the point can be moved while being measured, and the maximum value at that time can be specified as a leaking point. At this time, the value at the time of measurement is displayed on the display surface, and the measurer determines the maximum value by looking at the value. Thereby, a leak location can be specified in real time.
[0030]
On the other hand, when there is no piping diagram, in areas where gas leakage is assumed to occur, the sound collection position (A position, B position,. And the leakage sound is determined for each of the sound collection positions. Then, the maximum value of the leaked sound determined at each sound collection position (A position, B position,..., M position) is sequentially plotted on a map of the surrounding area, and contour lines are drawn, for example, FIG. ), The island or point having the maximum value is formed at the leakage location, and therefore the island region Q or point having the maximum value is specified as the leakage location.
[0031]
The leak location specifying means 3 outputs the location information of the leak location P or Q determined in this way, and performs printout or screen display.
[0032]
As described above, in this embodiment, since the sound leakage is determined only by performing predetermined computer processing on the sound collection information collected on the surface of the earth, it is possible to determine whether there is leakage with a simple configuration and at low cost. Can be confirmed.
[0033]
Also, if it is determined that there is a leak, it is also determined which piping system is installed, for example, whether it is an exposed pipe, a buried pipe, a concealed pipe, or whether it is a rubber pipe or a steel pipe. Since it was made possible, it is possible to accurately cope with subsequent pipe replacement work and the like.
[0034]
In addition, since the changeover switch function is provided, when the piping system installation status is known in advance, it is only necessary to switch to the leakage sound pattern information corresponding to the piping system installation status and perform pattern comparison. Can be performed more quickly.
[0035]
Furthermore, since the display is performed according to the confirmation of the leaked sound, it is possible to reliably notify the operator that the leak has occurred.
[0036]
In addition, based on the sound collection information collected using a microphone or the like on the surface of the earth, it was possible to identify the gas leak location by simply processing the sound collection information. It is possible to easily construct a system up to the identification at low cost.
[0037]
Further, since it is only necessary to collect sound on the ground surface using a microphone or the like, large-scale construction and facility arrangement are not required.
[0038]
Furthermore, when LP gas leaks from the buried pipe, the LP gas is heavier than air and thus does not appear on the ground surface, and it was difficult to detect with the conventional method using an odor sensor or a laser. Since the location is specified, it is possible to reliably detect and specify LP gas leakage from the buried pipe on the ground surface.
[0039]
In the above description, the sound collection data is obtained using the microphone 11 on the ground surface. However, the sound collection data is obtained using other means, for example, using an AE sensor attached to a pipe. May be. By performing filtering, pattern matching, etc. on the sound collection data detected and obtained using this AE sensor, it is possible to determine the leaked sound and determine which leaked sound corresponds to which piping installation situation. To do. In this way, as in the case of using the above-mentioned microphone, a system for detecting gas leakage can be easily constructed at low cost, and there is an effect that large-scale construction and facility arrangement are not required. In addition, external noise is less likely to enter the sound collection data, and noise removal, noise information removal, and the like can be performed more quickly.
[0040]
In addition, when specifying the leak location based on the sound collection data by the AE sensor, the method is specified from the time difference of the measurement waveform by the AE sensor attached to any two locations of the pipe, or the leak location is attached to any one location of the pipe. There is a method of specifying by combining the leaked sound detected by the AE sensor and the sound generated by an external factor at the end of the pipe.
[0041]
【The invention's effect】
Since this invention consists of an above-described structure, there can exist an effect which is demonstrated below.
According to the first aspect of the present invention, since the sound leakage is determined only by performing predetermined computer processing on the sound collection information collected on the surface of the earth, it is determined whether or not there is a leakage with a simple configuration and at a low cost. can do.
[0042]
Further, in the invention of this, when determined that there is leakage, either the leak sound is in one of the pipeline installation conditions, for example, either the exposed pipe, or buried pipes, or concealed piping, furthermore, if they the rubber tube Since it is also possible to determine whether it is a steel pipe, it is possible to accurately cope with subsequent pipe replacement work and the like.
[0043]
Further, in the invention of this, it is provided with the changeover switch function, when the piping system installation condition is known in advance, since it is sufficient to compare the pattern is switched to the leak sound pattern information, more deterministic leakage sound It can be done promptly.
[0044]
Furthermore, in the invention of this, in response to confirmation of the leakage sound, since to perform its display, it can be informed to ensure operator that a leak has occurred.
[0045]
In this invention, based on collected sound information collected using the microphone at the surface, only to computer processes the collected information, since to be able to identify the leakage location of the gas, sensing gas leakage However, a system for specifying the position can be easily constructed at low cost.
[0046]
Further, since it is only necessary to collect sound on the ground surface using a microphone or the like, large-scale construction and facility arrangement are not required.
[0047]
Furthermore, when LP gas leaks from the buried pipe, the LP gas is heavier than air and thus does not appear on the ground surface, and it was difficult to detect with the conventional method using an odor sensor or a laser. Since the location is specified, it is possible to reliably detect and specify LP gas leakage from the buried pipe on the ground surface.
[0048]
Further, in the invention this, the sound collection information detected by the AE sensor attached to the pipe, since to carry out the determination of the leakage sounds by performing predetermined computer processing, external noise is prevented from entering the sound collecting information Therefore, noise removal, noise information removal, and the like can be performed more quickly.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a gas leak detection system according to the present invention.
FIG. 2 is a flowchart showing a procedure executed by filter processing means.
FIG. 3 is an explanatory diagram of weighting processing.
FIG. 4 is a flowchart showing a procedure executed by leaked sound determination means.
FIGS. 5A and 5B are explanatory diagrams for specifying a leakage location. FIG. 5A is an explanatory diagram when a piping diagram is provided, and FIG. 5B is an explanatory diagram when a piping diagram is not provided.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filter processing means 2 Leakage sound determination means 3 Leak location specific means 11 Microphone 12 Recording tape 21 Screen 100 Gas leak detection system

Claims (5)

In the gas leakage detection system that detects gas leakage from the piping system,
Filter processing means for performing predetermined weighting processing on information in a predetermined frequency band extracted from sound collection information obtained by collecting sound on the ground surface and removing noise;
Leaked sound determination means for comparing the collected sound information subjected to the filtering process and noise information that has been patterned in advance by pattern matching, removing the noise information from the collected sound information, and determining the leaked sound information;
The above leakage sound information, and whether the leakage sound is exposed piping, buried piping or concealed piping, and leakage pattern information set in advance according to each piping system installation status of whether the piping is a rubber tube or a steel tube Leakage sound determination means for comparing the sound pressure and determining whether the leaked sound corresponds to which piping system installation situation;
The leaked sound information and the information on the sound collecting position from which the leaked sound information is obtained are set as one set, the position where the leaked sound is maximized is specified from the plurality of sets of information, and the position is set as a leaked part of the piping system Leak location identification means,
A gas leak detection system comprising: Among the above leakage sound pattern information, it has a changeover switch function for specifying which leakage sound pattern information is used.
The gas leakage detection system according to claim 1. According to the confirmation of the leak sound information by the leak sound determination means, the gas leak information is displayed.
The gas leak detection system according to claim 1 or 2, wherein The sound collection position in the leakage location specifying means is a position set along the piping system known from the piping diagram when the piping diagram is known, and a position set within an arbitrary range when there is no piping diagram.
The gas leak detection system according to any one of claims 1 to 3, wherein Instead of the sound collection information obtained by collecting sound on the ground surface, the sound collection information detected by the AE sensor attached to the pipe is used.
The gas leak detection system according to any one of claims 1 to 4, wherein

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