JP2599487B2 - Gas supply pipe leak monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention] (Industrial application field) The present invention relates to a gas supply pipe leak monitoring system. << Prior Art >> For example, a gas supply facility in an apartment house such as an apartment is configured as shown in FIG. In the figure, a gas supply source 1 such as a propane gas cylinder is shown.
And the gas inlet 3 of the apartment are connected by a gas supply pipe 4, and pressure regulators 5, 6 and a gas meter 7 are connected to the base side of the gas supply pipe 4. In addition, for example, valves 8 and 9 are connected to the gas intake 3 for each floor, and a valve 10 is provided for each household.
And gas consumption equipment by piping 12 through gas meter 11
13 is supplied with gas. On the other hand, a portion of the gas supply pipe 4 that is close to, for example, the apartment 2 is often buried underground because a passage or the like must be provided. Therefore, in this part, cracks may occur due to the load from the ground surface or cracks due to corrosion, etc.There is a possibility that gas may leak from the crack part, and it is necessary to monitor the presence or absence of gas leakage . Monitoring of this gas leak has conventionally been performed by the following method. (1) The operator checks the operation of the integrator of the gas meter 7 every day for about 30 days, selecting a time zone such as nighttime or late at night when the gas consumption is small, and compares the usage status of the nights to check for abnormalities. (2) The gas supply is temporarily stopped, the connection portion of the gas supply pipe 4 is disconnected, and pressurized air is introduced to perform an air tightness inspection. However, among the above monitoring methods (1), a worker must go to the site for about 30 days, which requires a large amount of labor. On the other hand, a gas meter that integrates a relatively large gas flow rate requires a large amount of labor. It is difficult to detect minute flow rates. In the method (2), since the gas supply must be temporarily stopped, the time period during which the inspection can be performed is restricted, and when the gas supply is resumed, the valves of the gas consuming facilities in each house are opened. A large amount of gas was released, which could lead to an accident. Therefore, the present applicant previously provided a first pressure regulator and a gas flow path bypassing the pressure regulator in the gas supply pipe, and provided the gas flow path with a second pressure regulator having a higher regulation pressure than the pressure regulator. A monitoring system using a pressure regulator and micro leak detection means has been developed. In this system, when the flow rate in the gas supply pipe is small and the pressure in the pipe is high, the first pressure regulator is closed, the gas is regulated by the second pressure regulator, and only the bypass flow path is Flows. Therefore, if the gas supply pipe leaks when the gas consumption almost stops at night, this gas flows through the bypass flow path and is detected by the detecting means. (Problems to be solved by the invention) However, even in this system, 30 days or 72 days
In a case such as this, it is necessary to have a time zone in which gas use is stopped for more than one hour during 0 hours, and if there are many households, gas may always be used somewhere. Could not fit. Further, in gas supply equipment having long pipes and many connection parts, a plurality of minute leaks unrelated to the accident are added, so that these may exceed the detection lower limit of the detection means and erroneous detection may occur. was there. Further, in this system, the magnitude of the leakage cannot be determined, and after the detection, it is necessary to perform the inspection again by, for example, the above-described means (2). The present invention solves the above-described problems, and makes a micro leak detection gas meter learn a normal gas flow trend pattern every day, and compares it with current data to detect the presence or absence of a leak. The present invention provides a leak monitoring system for a gas supply pipe. [Constitution of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a gas accumulating means interlocked with a gas meter connected to a gas supply pipe in a gas supply facility, and a signal from the accumulating means. By, the first computing means to calculate the gas flow tendency per unit time in the gas usage reduction time zone at night, and the minimum flow rate data obtained by the first computing means for a predetermined number of days,
The second operation means for calculating the minimum flow rate and the deviation value thereof in the normal state of the supply equipment, the average minimum flow rate data and the deviation value data obtained by this operation result, and the first operation means Alarm means for comparing the obtained current data with the current data and generating an alarm output when the values of the average minimum flow rate data and the deviation value data of the current data for a predetermined period exceed the average data. is there. Further, according to the present invention, a comparing means for comparing the lowest flow data of the previous day with the lowest flow data of the present day, and an alarm means for taking in the data from the comparing means and generating an alarm output when the lowest flow data rises every day. It can also be provided. Further, when the gas flow per unit time in the daily gas use reduction time period is recorded on a recorder, and when a clear abnormal record occurs from the flow rate record and the record until the previous day, that is, at night or midnight For example, when a large amount of gas flows continuously for a long time in a time zone that cannot be normally considered, it is possible to determine that an abnormality has occurred and output an alarm. (Operation) According to the above configuration, while measuring the flow rate inside the gas meter, the gas usage reduction time zone, the minimum flow rate and their deviation values are learned, and these total values are compared with the current data. It is determined whether the value of the current data is within the normal range, and an alarm output is generated when it is determined that the value is abnormal. In addition, it can be determined whether or not the pattern of the minimum value data for each day is abnormal by rising every day. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the system configuration of the present invention. Since the basic configuration of the entire gas supply facility does not change, the same reference numerals as those in the conventional example are used and the description thereof is omitted, but the gas meter 20 connected to the base side of the gas supply pipe 4 is omitted.
Has a flow rate detection mechanism, a CPU that takes in data detected by the detection mechanism and determines whether or not the data is normal, and a communication controller 24 that takes out data calculated by the CPU through a signal line 22. The data is transmitted to a host computer 28 on the center side through a telephone line 26. The data to be transmitted includes not only an alarm signal but also data for warning a replacement time, such as gas consumption data, for example. In the present invention, only gas leakage is dealt with. FIG. 2 shows the internal configuration of the gas meter 20. At the same time, the gas meter 20 forms a gas inlet 32a and a gas outlet 32b inside the meter housing 30 and constitutes a flow path on both sides, and is provided with a measuring unit 32 that converts this movement into a rotational movement with the gas flow. A shutoff valve 38 composed of a self-holding bidirectional solenoid or the like having a valve body 36 protruding from a nozzle 34 provided in the vicinity of the gas inlet 32a, and an operation detection sensor 38a attached to the shutoff valve 38 are provided. I have. A rotating disk 40, which rotates in synchronization with the rotation inside the measuring unit 2, protrudes above the measuring unit 2, and the rotation of the rotating disk 40 is detected by a flow rate sensor 42. The housing 30 is provided with a display unit 44. The solenoid 38, the operation detection sensor 38a, the flow sensor 42, the display unit 44, and the signal line 22 are connected to the CPU 48 including a microcomputer or the like via an input / output interface 46.
It is driven using a battery (not shown) built therein. In the above configuration, the gas flows to the lower side of the gas supply pipe 4 through the measuring unit 32, the measuring unit 32 rotates according to the usage state of the gas equipment, and the flow sensor according to the rotation of the rotating disk 40.
42 detects. The CPU 48 receives the detection signal of the flow sensor 42 and sequentially displays the integrated value according to the flow rate on the display unit 44,
In addition to notifying the center of the consumption data according to the time through the signal line 22, an arithmetic operation for constantly monitoring the micro leakage at the initial stage of the operation of the equipment is executed. FIG. 3 shows a flowchart of the process. First, the detection period is set to the A day at the start, then the flow rate per unit time at midnight of the day is calculated and stored in the storage unit. At this point, the minimum consumption amount and the time zone on the day are stored as a pair of data in the storage unit, and the other data is deleted. This operation is repeated from the first day to the A day, and thereafter, the upper limit and the lower limit of the minimum consumption which is the minimum consumption P on each day are calculated, and the upper limit OFF peak value R1 in a normal state is calculated,
This value is stored (steps 1 to 8). Note that the upper limit OFF peak value R1 is calculated from the OFF peak detection value in a predetermined period, and is set as an upper limit OFF peak flow rate at which an OFF peak abnormality is determined in consideration of variation. If this data is obtained, the data P of that day is detected until the set period A in the same procedure as the next, and each data P1 is detected.
Calculate the OFF peak value data R2 in the same procedure as on the basis of ＰPA (steps 9 to 13), and calculate this value R2 and the set value.
The OFF peak value R1 is compared, and if R2 ≦ R1, that is, if the value does not exceed the OFF peak value, step 9 is performed again.
Then, the same measurement and calculation as described above are performed. When R2> R1, if it is determined that the consumption is large, an alarm output is generated and a warning is displayed on the host computer 28 on the center side through the above-mentioned telephone line 26 (steps 14 and 15). ). In addition, a command from the center can be issued by two-way communication to shut off the shut-off valve 38, and when it is determined that there is an abnormality, a shut-off pulse is output by the CPU 48 and the shut-off operation is performed. You can also. Further, actual data can be sent together with the alarm signal. Then, after the inspection and restoration work of the equipment by hand (step 16), the flow returns to step 1 again, and the same measurement and calculation as described above are performed. FIG. 4 shows the execution means according to the second embodiment. First, the detection period is set to A day as in the first embodiment, and the OFF peak value from the minimum flow rate P1 to PA on each day is set. R1 is calculated and k is set to 0 (steps 1 to 10). From the next day, the minimum flow rate is detected, and this value is applied to the calculation formula of step 9 in a state shifted one day at a time, and a calculated value R2 of the day is obtained, and it is determined whether this value is larger than the set value R1. Calculate,
If determined to be no, calculate the value the next day with the day shifted
Repeat the process to find R2. If it is determined that the value is larger than the set value R1, k = k +
When the value becomes x, that is, when the OFF peak value continuously rises for several days, an alarm output is generated (steps 11 to 20), and a manual return operation (step 2) is performed.
After 0), the process returns to step 1 again. That is, in this embodiment, the obtained data is a daily rising pattern, and if this state continues for several days, it is determined that there is an abnormality, and an abnormal signal is output to the center side in the same manner as described above. When the supply pipe 4 is cracked due to the load, the cracked portion increases daily due to the repeated load, and the amount of gas leakage is increased. In each embodiment, only the micro leakage was described.However, the gas flow per unit time in the daily gas use reduction time zone was recorded on a recorder, and it was clear from the flow rate record to the previous day's record. It is also possible to output an alarm when abnormal recording occurs, that is, when a large amount of gas flow continues continuously for a long period of time, such as at night or late at night when it is not normally conceivable, and it is determined to be abnormal. Of course.

【The invention's effect】

As described in detail in the above embodiments, in the gas supply pipe leakage monitoring system according to the present invention, while measuring the flow rate inside the gas meter, the gas use reduction time zone, the minimum flow rate, and the deviation thereof By learning the values and comparing these total values with the current data to determine whether the current data value is within the normal range, or by increasing the daily minimum data pattern by day Since it is possible to judge whether or not there is an abnormality and generate an alarm output, there is no need to dispatch a measurement staff, temporarily stop gas for measurement, or use other equipment to perform measurement as in the past. It is also possible to check for mass leakage at an early stage.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a gas supply system according to a first embodiment of the present invention, FIG. 2 is an explanatory view showing an internal configuration of a gas meter, FIG. 3 is a flowchart showing an execution state of a monitoring system for minute leaks, FIG. FIG. 5 is a flowchart showing an execution state of monitoring for minute leakage according to the second embodiment, and FIG. 5 is an explanatory diagram showing a conventional gas supply facility. 4 Gas supply pipe 20 Gas meter 22, 24, 26, 28 Alarm means (22 Communication line, 24 Communication controller, 26 Telephone line, 28 Host computer) 42 Flow sensor 48 …… CPU

Claims (2)

(57) [Claims] 1. A gas integrating means interlocked with a gas meter connected to a gas supply pipe in a gas supply facility, and a signal from the integrating means calculates a gas flow tendency per unit time in a time zone in which gas usage is reduced at night. The first arithmetic means, and the second arithmetic means for capturing the minimum flow rate data obtained by the first arithmetic means for a predetermined number of days, calculating the minimum flow rate when the supply equipment is normal and the deviation thereof. Comparing the average minimum flow rate data and the deviation value data obtained by the calculation result with the current data obtained by the first calculation means, and calculating the average minimum flow rate data and the deviation of the current data for a predetermined period of time. And a warning means for generating a warning output when the value of the value data exceeds the average data. 2. A comparison means for comparing the minimum flow data of the previous day with the minimum flow data of the present day, and an alarm means for taking in data from the comparison means and generating an alarm output when the minimum flow data rises every day. 2. The gas supply pipe leakage monitoring system according to claim 1, further comprising: