JPH0464787A - Leak monitoring system for gas supply pipe - Google Patents

Abstract

PURPOSE:To detect existence of leak by letting a fine leak detecting gas meter learn a daily normal gas flow motion pattern, and comparing it with current data. CONSTITUTION:A gas meter 20 has a flow detection mechanism, a CPU to determine if data detected by it are normal or not, and a communication controller 24 to take out data computed by the CPU through a signal line 22, and the data are sent to a host computer 28 on the center side through a telephone line 26. First, a flow per uit time is computed, the minimum consumption and time zone for it are memorized in a memorizing part, these are repeated for a predetermined period, the upper limit and the lower limit of the minimum consumption are computed, an upper limit off peak value R1 for a normal time is computed, and this value is stored. Off peak value data R2 for a predetermined period are computed in similar procedures, and when it is determined that the consumption is too large (R2>R1), an alarm is displayed in the host computer 28.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a leak monitoring system for gas supply pipes.

(Prior Art) For example, gas supply equipment in a housing complex such as a condominium is configured as shown in FIG.

In the figure, a gas supply source 1 such as a propane gas cylinder and a gas intake port 3 of an apartment are connected by a gas supply pipe 4, and pressure regulators 5, 6 and a gas meter 7 are connected to the base of the gas supply pipe 4. ing.

In addition, valves 8 and 9 are connected to the gas intake port 3 for each floor, and one valve for each household.
Gas is supplied to the gas consumption installation i*13 via the pipe]-2 via the gas meter 11 and the gas meter 11.

On the other hand, the portion of the gas supply pipe 4 that is close to the condominium 2, for example, is often buried underground because it is necessary to provide a passage or the like.

Therefore, in this area, cracks may occur due to loads from the ground surface or cracks may occur due to corrosion, etc., and gas is used to leak from the cracks, so it is necessary to monitor for gas leaks.

Conventionally, monitoring of this gas leakage was performed using the following method.

(1) A worker selects a time when gas consumption is low, such as at night or late at night, and checks the movement of the totalizer of the gas meter 7 every day for about 30 days, and compares the usage status from consecutive nights to see if there are any abnormalities.

(2) Temporarily stop the gas supply, disconnect the connection of the gas supply pipe 4, introduce pressurized air, and perform an airtightness test.

However, among the above monitoring methods, method (1) requires workers to be on site for about 30 days and requires a large amount of labor. It is difficult to detect minute flow rates.

In addition, with method (2), the gas supply must be temporarily stopped, which limits the time slots in which inspections can be performed. A large amount of gas was released and there was a risk of an accident.

Therefore, the applicant first provided the gas supply pipe with a first pressure regulator and a gas flow path that bypassed this pressure regulator,
We have developed a monitoring system in which a second pressure regulator with a higher regulation pressure than the pressure regulator and microleak detection means are provided in this gas flow path.

In this system, when the flow rate flowing through the gas supply pipe is small and the pressure inside the pipe becomes high, the first pressure regulator is blocked and the gas is pressure regulated by the second pressure regulator, allowing only the bypass flow path to flow. flows.

Therefore, if there is a leak in the gas supply pipe when gas consumption has almost stopped at night, this gas flows through the bypass passage and is detected by the detection means.

(Problem to be solved by the invention) However, even with this system, 30 days or 7 days
There must be a time period during which gas usage is stopped for more than an hour during a 20-hour period, and if there are many households supplied, gas may always be in use somewhere, so in such a case, Couldn't fit. In addition, in gas supply equipment with long piping and many connections, multiple small leaks unrelated to the accident will be added, and there is a risk that these may exceed the lower detection limit of the detection means, resulting in false detection. was there.

In addition, this system cannot determine the size of a leak, and after detection, it is necessary to re-inspect by using the above-mentioned method (2), for example.

This invention solves the above problems by making a micro leakage detection gas meter learn daily normal gas flow rate trend patterns, and by comparing this with current data, it is possible to detect the presence or absence of a leak. The present invention provides a leak monitoring system for gas supply pipes.

[Configuration of the Invention (Means for Solving the Problems) To achieve the above object, this invention provides a gas integration means that is linked to a gas meter connected to a gas supply pipe in a gas supply facility, and a gas integration means that In response to the signal, a first calculating means calculates the gas flow rate trend per unit time during the time period when gas usage is reduced at night, and the lowest flow rate data obtained by the first calculating means is acquired for a predetermined number of days, a second calculation means for calculating the minimum flow rate and their deviation value during normal operation of the equipment; average minimum flow rate data and deviation value data obtained from this calculation result; The apparatus is provided with an alarm means for comparing the current data with the average minimum flow rate data for a predetermined period of the current data and generating an alarm output when the values of the average minimum flow rate data and the deviation value data of these data exceed the average data.

The present invention also includes a comparison means for comparing the previous day's lowest flow rate data with today's lowest flow rate data, and an alarm means for capturing data from the comparison means and generating an alarm output when the lowest flow rate data increases each day. You can also set one up.

Furthermore, when the gas flow per unit time during the daily gas usage reduction period is recorded on a recorder and an obvious abnormality occurs when comparing this flow rate record with the record up to the previous day,
In other words, it is possible to determine that an abnormality is occurring and output an alarm when a large amount of gas flows continuously for a long period of time, such as at night or late at night, when normal people cannot detect it.

(Function) According to the above configuration, while measuring the flow rate inside the gas meter, it learns the period of reduced gas usage, the lowest flow rate, and their deviation values, and compares these total values with the current data. The system determines whether the current data value is within the normal range, and generates an alarm if it is deemed abnormal.

Furthermore, it can be determined whether or not there is an abnormality by observing that the pattern of daily minimum value data increases day by day.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described in detail using the drawings.

FIG. 1 shows the system configuration of this invention.

Since the basic configuration of the gas supply equipment as a whole remains the same, the same reference numerals as in the conventional example will be used and the explanation will be omitted.
A gas meter 20 connected to the base of the gas supply pipe 4 has a flow rate detection mechanism and data detected by this detection mechanism, and receives data calculated by a CPU and cPU that takes in the data detected by this detection mechanism and determines whether it is normal or not. signal line 22
It is equipped with a communication controller 24 that takes out data through a telephone line 26 and sends the data to a host computer 28 on the center side.

Note that the data sent includes not only alarm signals, but also data such as gas consumption data to warn when it is time to replace the gas, but in this invention, only small gas leaks will be dealt with.

FIG. 2 shows the internal structure of the gas meter 20.

The gas meter 20 in the figure has a meter housing 30
A measuring section 32 is provided which forms a gas inlet 32a and a gas outlet 32b that form a flow path on both sides inside the gas flow chamber, and converts this movement into rotational movement as the gas flows, and is provided near the gas inlet 32a. A cutoff valve 38 consisting of a self-holding formation direction solenoid or the like having a protruding valve body 36 facing the nozzle 34 and an operation detection sensor 38a attached to the cutoff valve 38 are provided.

Further, a rotating disk 40 that rotates in synchronization with the internal rotational movement of the measuring section 2 protrudes from the upper part of the measuring section 2, and the rotation of the rotating disk 40 is detected by a flow sensor 42.

Further, the housing 30 is provided with a display section 44 .

These solenoids38. The motion detection sensor 38a, the flow rate sensor 42, the display section 44, and the above-mentioned signal line 22 are connected to the above-mentioned CPU 48 consisting of a microcomputer etc. through an input/output interface 46, and these are built in the housing 1. It is powered by a battery (not shown) as a power source.

In the above configuration, gas flows to the downstream side of the gas supply pipe 4 through the metering section 32, the metering section 32 rotates according to the usage status of the gas appliance, and the flow rate sensor 42 detects the rotation according to the rotating disk 400 revolutions. .

Upon receiving the detection signal from the flow rate sensor 42, the CPU 48 causes the display section 44 to sequentially display integrated values according to the flow rate, and not only reports the consumption data depending on the time to the center side through the signal line 22, but also controls the operation of the equipment. At the initial stage, calculations are performed to constantly monitor microleakage.

Fig. 3 shows the flowchart. First, at the start point, the detection period is set on day A, and then the flow rate per unit time in the middle of the night of that day is calculated and stored in the storage unit. At the time of completion, the minimum consumption amount and the time period of the day are stored as a pair of data in the storage unit,
Erase other data.

■Repeat this process from the first day to day A, then calculate the upper and lower limits of the minimum consumption amount that will be the minimum consumption amount P for each day, calculate the upper limit OFF peak value R1 in normal times, and store this value. (Steps 1 to 8 above).

Note that this upper limit OFF peak value R1 is the OFF peak value R1 for a predetermined period.
Calculate from the F peak detection value and take the variation into account and turn it off.
The upper limit of the OFF peak flow rate is determined as a peak abnormality.

■Once this data has been obtained, next, use the same procedure as in ■ to detect the data P of the day until the set period A, and each data P
Calculate the OFF peak value data R2 based on 1 to PA using the same procedure as step 9 to 13). Compare this value R2 with the OFF peak value R1, which is the set value, and find that R2≦R1.
, that is, if the value does not exceed the OFF peak value, the process returns to step 9 and the same measurements and calculations as in (2) above are performed.

In addition, when R2>R1, if it is determined that the consumption amount is large, an alarm output is generated and the above-mentioned telephone line 2
6, a warning is displayed on the host computer 28 on the center side (steps 14 and 15).

In addition, the center side can issue a command through two-way communication to cause the shutoff valve 38 to shut off, and when it is determined that an abnormality has occurred, the CPU 48 outputs a shutoff pulse to cause the shutoff operation, and at the same time the center side You can also report it.

Furthermore, actual data can also be sent along with the alarm signal.

Then, after manually inspecting and restoring the equipment (step 16), the process returns to step 1 and performs the same measurements and calculations as described above.

Moreover, FIG. 4 shows the execution means according to the second embodiment. First, the detection period is set to day A as in the first embodiment,
OFF peak value R1 from the minimum flow rate Pi-PA for each day
is calculated and set to k-0 (steps 1 to 10). Detect the minimum flow rate from the next day, apply this value to the formula in step 9 with a shift of one day at a time, obtain the calculated value R2 for that day, and check whether this value is greater than the set value R1. If the calculation is negative, the operation to obtain the calculated value R2 is repeated the next day with another day.

Also, if it is determined that the value is greater than the set value R1, the value will be changed to +.
1 and when the value becomes X, that is, when the OFF peak value continues to rise for several days, an alarm output is generated (steps 11 to 20), and after manual recovery work (step 20), step again. Return to 1.

In other words, in this embodiment, the data obtained is a daily rising pattern, and if this state continues for several days, it is determined that there is an abnormality, and an abnormality signal is output to the center side in the same way as above. The criteria for judgment is that if the supply pipe 4 cracks due to the load, the cracked area will increase day by day due to the addition of the edge-turning load, and this will increase the amount of gas leakage.

In addition, in each example, only microleakage was explained.
When a recorder records the gas flow per unit time during the daily reduced gas usage period and compares this flow rate record with the previous day's record, an obviously abnormal record occurs, such as at night or late at night. Of course, it is also possible to determine that there is an abnormality and output an alarm when a large amount of gas flows continuously for a long time during an uncontrollable time period.

Effects of the Invention 1 As explained in detail in the above embodiments, the gas supply pipe leak monitoring system according to the present invention measures the flow rate inside the gas meter and detects the minimum Learn the flow rates and their deviation values, and compare these total values with the current data to determine whether the current data values are within the normal range, or if the pattern of the daily minimum value data is different from day to day. It is possible to determine whether or not there is an abnormality by rising to a certain level, and generate an alarm output. There is no need to measure
It is also possible to check for large amounts of leakage at an early stage.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the gas supply equipment according to the first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the internal configuration of a gas meter, FIG. 3 is a flowchart showing the execution state of the microleak monitoring system, and FIG. The figure is a flowchart showing the execution state of microleakage monitoring according to the second embodiment, and FIG. 5 is an explanatory diagram showing the conventional gas supply equipment. 4...Gas supply pipe 20...Gas meter 22.24, 26.28...Alarm means (22...Communication line, 24...Communication controller, 26...Telephone line, 2
8...Host computer) 42...Flow rate sensor 48...CPU Agent Patent attorney Hidekazu Miyoshi Diagram 2 procedural amendment (release) 6゜Subject of amendment, 21 deception□4 Yozuhaku↑ Contents of correction / @ki1mi (sai n + (&i 1,000 u, θ history 4t, general hitani)
；G、Special Italy Patent Application No. 17t/// 2008 Patent Application No. 2 2. Name of invention

Claims (2)

[Claims] (1) A gas integration means linked to a gas meter connected to a gas supply pipe in the gas supply equipment, and a gas integration means that calculates the gas flow rate trend per unit time during the time period when gas usage is reduced at night based on the signal from the integration means. a second calculation means that takes in the minimum flow rate data obtained by the first calculation means for a predetermined number of days and calculates the minimum flow rate during normal operation of the supply equipment and the deviation value thereof; Compare the average minimum flow rate data and deviation value data obtained from the calculation results with the current data obtained by the first calculation means, and calculate the average minimum flow rate data and deviation value data for a predetermined period of the current data. A leakage monitoring system for a gas supply pipe, comprising: an alarm means for generating an alarm output when the value of exceeds the average data. (2) Comparison means for comparing the previous day's minimum flow rate data with today's minimum flow rate data, and an alarm means for capturing data from this comparison means and generating an alarm output when the minimum flow rate data increases each day. Claim 1 characterized in that
Leakage monitoring system for the gas supply pipes described.