JP6475370B1 - Leakage location estimation device - Google Patents

Abstract

In maintenance of a cable filled with gas, a gas leakage point is specified to improve maintenance efficiency.
A database 14 holds a plurality of gas pressure distribution calculation values obtained by assuming leakage locations as closures 5A, 5B,..., 5N, respectively, and a calculation unit 12 includes a pressure transmitter 3A, 3B,..., 3N based on the measurement results of the gas pressure distribution and the gas pressure distribution calculated values held in the database 14 are calculated, and the estimation unit 13 calculates the gas pressure having the maximum correlation. The closures 5A, 5B,..., 5N corresponding to the distribution calculation values are estimated as leaking points.
[Selection] Figure 2

Description

  The present invention relates to a technique for remotely monitoring a communication cable disposed in an underground facility.

  In maintenance of a metal cable arranged in an underground facility, gas is supplied from the facility building into the metal cable, and the pressure of the gas is monitored by a pressure sensor installed in a closure attached to the metal cable. When gas leaks, a person with advanced skills has identified the gas leak location based on experience using the gas pressure distribution in the facility created from the measurement data of the pressure sensor.

Tomoka Akimura, Naoko Osuka, Toshimi Mitsuhashi, “Improvement of computational efficiency by introducing implicit method into pipeline fluid analysis software”, Advanced Simulation, Advance Software Co., Ltd. July 2017, Vol. 24, pp. 12-49

  However, in underground metal cable maintenance, if a person with advanced skills has identified the location of the gas leak based on the identification of the location of the closure, if the location of the gas leak is incorrect, investigate other closures again. There was a problem that it took time.

  Further, although a high level of skill is required to identify a gas leak location, a technique that can identify a gas leak location has been desired even for those with low skills.

  The present invention has been made in view of the above, and an object of the present invention is to specify a gas leakage point in maintenance of a cable filled with gas and improve maintenance efficiency.

The leak location estimation apparatus according to the present invention is a leak location estimation apparatus that estimates a gas leaked closure in a facility in which a pressure transmitter for measuring gas pressure is installed in a closure attached to a cable filled with gas. For each closure in the facility, a database holding a gas pressure distribution calculation value indicating a distribution of gas pressure in the facility determined on the assumption that gas has leaked from the closure, and from the pressure transmitter Correlation degree calculating means for calculating the degree of correlation between the gas pressure distribution actual measurement value based on the obtained actual measurement value and each of the gas pressure distribution calculation values held in the database; and the gas pressure distribution calculation with the highest correlation degree It has a leakage point determining means for determining the closure corresponding to the value as closure gas is leaked, and the correlation calculation The means identifies the first closure having the lowest gas pressure and the second closure having the second lowest gas pressure based on the actual measurement value obtained from the pressure transmitter, and the second closure from the first closure is the second closure. A degree of correlation between each of the gas pressure distribution calculation values corresponding to the closure existing until the closure and the gas pressure distribution measurement value is calculated .

  ADVANTAGE OF THE INVENTION According to this invention, in the maintenance of the cable with which gas is filled, a gas leak location can be specified and the maintenance efficiency improvement can be aimed at.

1 is an overall configuration diagram of a gas pressure remote monitoring system including a leak location estimation device of the present embodiment. It is a functional block diagram which shows the structure of the leak location estimation apparatus of this embodiment. It is a flowchart which shows the flow of a process of the leak location estimation apparatus of this embodiment.

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

  FIG. 1 is an overall configuration diagram of a gas pressure remote monitoring system including a leak location estimation apparatus 1 of the present embodiment. The gas pressure remote monitoring system shown in the figure includes a leak point estimation device 1, a gas pressure monitoring device 2, and pressure transmitters 3A, 3B,..., 3N, and a metal cable 4 disposed in an underground facility. It is a system that monitors the pressure of the gas filled in and estimates and displays the location of gas leakage in the event of an abnormality.

  The metal cable 4 is supplied with dry air or nitrogen gas at a constant pressure from a gas supply device (not shown) installed in an equipment building or the like. Closures 5A, 5B,..., 5N that seal the connection points are attached to the connection points of the metal cable 4.

  In the closures 5A, 5B, ..., 5N, pressure transmitters 3A, 3B, ..., 3N for measuring the gas pressure in the closures 5A, 5B, ..., 5N are installed. Note that the pressure transmitters 3A, 3B,..., 3N may not be installed in all the closures 5A, 5B,.

  The pressure transmitters 3 </ b> A, 3 </ b> B,..., 3 </ b> N convert the measured gas pressure into an electrical signal and transmit it in response to the calling signal from the gas pressure monitoring device 2.

  The gas pressure monitoring device 2 transmits a calling signal to the pressure transmitters 3A, 3B,..., 3N at a predetermined timing, and collects the gas pressure in each of the closures 5A, 5B,. When an abnormality is recognized in the collected gas pressure, the gas pressure monitoring device 2 transmits the collected gas pressure to the leak location estimation device 1 in order to estimate the leak location of the gas. For example, when any of the gas pressures measured by the pressure transmitters 3A, 3B,..., 3N is equal to or lower than a predetermined threshold, the gas pressure monitoring device 2 determines that the gas is leaking.

  The leak location estimation device 1 is a gas pressure distribution (hereinafter referred to as “measured value of gas pressure distribution”) obtained from the pressure transmitters 3A, 3B,... ) And each of the gas pressure distributions (hereinafter referred to as “gas pressure distribution calculation values”) obtained by assuming that each of the closures 5A, 5B,. The closures 5A, 5B,..., 5N corresponding to the gas pressure distribution calculation values that have the maximum correlation with the distribution actual measurement values are estimated as leak points.

  A single gas pressure monitoring device 2 may monitor a plurality of metal cable networks. In this case, for each metal cable network, a gas pressure distribution calculation value assuming that each of the closures arranged in the metal cable network is a leak point is obtained.

  Next, the leak location estimation apparatus of this embodiment will be described.

  FIG. 2 is a functional block diagram showing the configuration of the leaked part estimation apparatus 1 of the present embodiment. The leak location estimation apparatus 1 shown in FIG. 1 includes an acquisition unit 11, a calculation unit 12, an estimation unit 13, and a database 14. Each part with which the leak location estimation apparatus 1 is provided is good also as what is comprised by the computer provided with the arithmetic processing apparatus, the memory | storage device, etc., and the process of each part is performed by a program. This program is stored in a storage device included in the leak location estimation apparatus 1, and can be recorded on a recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, or provided through a network. Hereinafter, each part will be described.

  The database 14 holds a plurality of gas pressure distribution calculation values obtained by assuming that the leakage points are the respective closures 5A, 5B,..., 5N. Specifically, for each of the closures 5A, 5B,..., 5N, it is assumed that each of the closures 5A, 5B,. The gas pressure distribution calculation value is calculated by, for example, the pipeline system fluid analysis technique of Non-Patent Document 1 using the number of lines, the type of closure, the connection point, the presence or absence of branching, and the like. That is, the database 14 holds N gas pressure distribution calculation values when each of the N closures 5A, 5B,.

  The database 14 may hold, for each of the closures 5A, 5B,..., 5N, time-series gas pressure distribution calculation values from a healthy state to an equilibrium state after a gas pressure drop. Further, the database 14 may calculate the gas pressure distribution by changing the gas leakage rate for each of the closures 5A, 5B,..., 5N, and hold the calculated gas pressure distribution value for each leakage rate.

  The acquisition part 11 acquires the gas pressure distribution actual value measured by the pressure transmitters 3A, 3B, ..., 3N.

  The calculation unit 12 correlates the measured gas pressure distribution value acquired by the acquisition unit 11 with each of the calculated gas pressure distribution values calculated on the assumption that gas has leaked from the respective closures 5A, 5B,. Calculate the degree. A well-known technique can be used for the calculation of the degree of correlation. The calculation part 12 should just be able to search the gas pressure distribution calculation value nearest to the gas pressure distribution actual measurement value.

  When the database 14 holds time-series gas pressure distribution calculation values for the respective closures 5A, 5B,..., 5N, the calculation unit 12 calculates the gas pressure distribution actual measurement values and the respective closures 5A, 5B,. The degree of correlation with each of the 5N time-series gas pressure distribution calculation values may be calculated. When the database 14 holds the gas pressure distribution calculation value for each leakage speed, the calculation unit 12 calculates the gas pressure distribution actual measurement value and the gas pressure distribution calculation for each of the closures 5A, 5B,. The degree of correlation with each of the values may be calculated.

  The estimation unit 13 estimates and outputs the closures 5A, 5B,..., 5N corresponding to the gas pressure distribution calculation value having the maximum correlation derived by the calculation unit 12 as a leak location. When the elapsed time after gas leakage and the leakage speed can be estimated, these pieces of information may be output.

  Next, the process of the leakage location estimation apparatus of this embodiment is demonstrated.

  FIG. 3 is a flowchart showing the flow of processing of the leak location estimation apparatus 1 of the present embodiment. When an abnormality occurs in the gas pressure, the leak location estimation device 1 starts the process of FIG.

  The acquisition unit 11 acquires gas pressure distribution actual measurement values measured by the pressure transmitters 3A, 3B, ..., 3N (step S11).

  The calculation unit 12 calculates the degree of correlation between the measured gas pressure distribution value acquired in step S11 and each of the calculated gas pressure distribution values held in the database 14 (step S12).

  The estimation unit 13 estimates the closures 5A, 5B,..., 5N corresponding to the calculated gas pressure distribution values having the highest degree of correlation obtained in step S12 as leakage locations (step S13).

  Next, a modified example of the process for estimating the leak location will be described.

  The first modification is an embodiment that uses time-series measured gas pressure distribution values and time-series calculated gas pressure distribution values.

  The database 14 holds, for each of the closures 5A, 5B,..., 5N, time-series gas pressure distribution calculation values from a healthy state before the occurrence of gas leakage to an equilibrium state after the gas pressure is reduced. . For example, time-series gas pressure distribution calculation values every several hours or every day from the healthy state to the equilibrium state are held.

  The acquisition unit 11 acquires time-series measured gas pressure distribution values. Considering that the gas pressure drop will reach an equilibrium state within a few days, at least the daily acquisition data will be the time-series measured gas pressure distribution measurement values, making it easier to find the characteristics of the gas pressure drop and The magnitude relationship is clarified, and improvement in the accuracy of leak point estimation can be expected.

  The calculation unit 12 calculates the degree of correlation between the time series gas pressure distribution calculation values of the respective closures 5A, 5B,..., 5N and the time series gas pressure distribution actual measurement values acquired by the acquisition unit 11. .

  The estimation unit 13 estimates a leakage location based on the degree of correlation obtained by the calculation unit 12.

  By obtaining the degree of correlation between the time-series data, it is possible to estimate the leak location with high accuracy in consideration of the leak process.

  The second modification also uses time-series gas pressure distribution calculation values, but the calculation amount is reduced by narrowing down the gas pressure distribution calculation values for calculating the degree of correlation based on the progress of the measured gas pressure distribution values. It is an example.

  Similar to the first modification, the database 14 holds time-series gas pressure distribution calculation values.

  The calculation unit 12 obtains a pressure drop value per time by comparing the latest measured gas pressure distribution value and the immediately preceding measured gas pressure distribution value. For example, the gas pressure drop value at any point in the facility may be averaged to obtain a pressure drop value per hour, or the drop value at the most gas pressure drop point at any point in the facility per hour It is good also as a pressure drop value.

  The calculation unit 12 acquires a gas pressure distribution calculation value having a pressure drop value per time corresponding to the obtained pressure drop value per time from the time-series gas pressure distribution calculation values held in the database 14, The degree of correlation with the actual measurement value of the gas pressure distribution is calculated. For example, the calculation unit 12 acquires a gas pressure distribution calculation value having a pressure drop value per hour within a predetermined range with reference to the pressure drop value per hour obtained from the actual measurement value.

  Since the calculation unit 12 does not calculate the degree of correlation between all the time-series gas pressure distribution calculation values and the gas pressure distribution actual measurement values, the calculation amount can be reduced.

  The third modified example is an embodiment in which the amount of calculation is reduced by narrowing the leaked portion from the pressure drop portion of the gas pressure distribution actual measurement value.

  The calculation unit 12 compares the actual measured gas pressure distribution with the gas pressure distribution in a healthy state, and among the closures 5A, 5B,. Identify the closed closure Q.

  The calculation unit 12 acquires the gas pressure distribution calculation value of the closure existing between the closures P and Q among the gas pressure distribution calculation values of the respective closures 5A, 5B,. The degree of correlation with the pressure distribution measured value is calculated.

  Since the calculation unit 12 does not calculate the degree of correlation for the gas pressure distribution calculation values of all the closures 5A, 5B,..., 5N, the calculation amount can be reduced.

  The third modification may be implemented in combination with the first and second modifications.

  In addition, as a method of narrowing down the leak location, calculation is performed by sequentially calculating from the closures 5A, 5B,... The amount can be reduced and high-speed output can be realized.

  As described above, according to the present embodiment, the database 14 holds a plurality of calculated gas pressure distribution values obtained by assuming that the leakage location is each of the closures 5A, 5B,. The calculation unit 12 calculates the degree of correlation between the measured gas pressure distribution values based on the measurement results of the pressure transmitters 3A, 3B,..., 3N and the calculated gas pressure distribution values held in the database 14, and the estimation unit 13 estimates the closure 5A, 5B,..., 5N corresponding to the gas pressure distribution calculated value with the maximum correlation as the leak location, so that the gas leak location can be estimated regardless of the presence or absence of skills. It can contribute to improvement of maintenance efficiency.

DESCRIPTION OF SYMBOLS 1 ... Leak location estimation apparatus 11 ... Acquisition part 12 ... Calculation part 13 ... Estimation part 14 ... Database 2 ... Gas pressure monitoring apparatus 3A, 3B, 3N ... Pressure transmitter 4 ... Metal cable 5A, 5B, 5N ... Closure

Claims (1)

In a facility in which a pressure transmitter for measuring gas pressure is installed in a closure attached to a cable filled with gas, a leakage point estimation device for estimating a gas leakage closure,
For each closure in the facility, a database holding gas pressure distribution calculation values indicating the distribution of gas pressure in the facility determined assuming that gas has leaked from the closure,
Correlation degree calculating means for calculating the correlation degree between the gas pressure distribution actual measurement value based on the actual measurement value obtained from the pressure transmitter and the gas pressure distribution calculation value held in the database;
A leakage point determination means for determining the closure corresponding to the gas pressure distribution calculated value having the highest correlation as a closure in which gas has leaked ,
The correlation degree calculating means identifies the first closure having the lowest gas pressure and the second closure having the second lowest gas pressure based on the actual measurement value obtained from the pressure transmitter, and the first closure. A leak point estimation apparatus characterized by calculating a degree of correlation between each of the calculated gas pressure distribution values corresponding to a closure existing between the first and second closures and the measured gas pressure distribution value .

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