JP3438955B2 - Gas leak detection device for common piping - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas leak detecting device for detecting gas leak in a common pipe such as an apartment house.

[0002]

2. Description of the Related Art In the case where gas is supplied to each dwelling unit through a common pipe, unlike the dwelling unit pipe that is normally arranged to check gas leaks individually, it is possible to find a gas leak in the common pipe portion. There was a problem that was delayed. Further, even when the occurrence of gas leakage is confirmed due to odor or the like, there is a problem that it takes time to specify that the gas leakage occurrence location is the common pipe. However, heretofore, there has been no suitable detection device capable of easily and reliably detecting such a gas leak in the common pipe.

[Problems to be Solved by the Invention]

Therefore, a first object of the present invention is to provide an original gas meter for measuring the total flow rate of gas supplied to each dwelling unit at the entrance of the common pipe, and to measure the dwell unit gas flow rate by each dwell unit gas meter. It is an object of the present invention to provide a gas leak detection device capable of automatically detecting a gas leak in a common pipe and issuing an alarm or immediately cutting off the gas supply by constantly checking the flow rate difference from the total.

In addition, as described above, when the flow rates of a large number of dwelling unit gas meters are summed up, the tolerances of individual dwelling unit gas meters also accumulate, and this becomes a noise component, making it difficult to detect gas leaks. . Therefore, the second object of the present invention is to accumulate the data of the flow difference between the original gas flow rate of the common pipe and the total of the dwelling unit gas flow rate in the normal time, and correct the error by using this as the gas leak measurement offset. By doing so, it is possible to detect gas leaks with high accuracy.

[0005]

In order to achieve the above object, the structure according to claim 1 of the present invention is, for example, as shown in FIGS. A dwelling unit gas meter 5 is provided, and an electronic original gas meter 6 is provided near the entrance of the common pipe 3, and the total S of dwelling unit gas flow rates mi measured by each dwelling unit gas meter 5 and the original gas meter 6 are measured. The gas flow rate M is compared, and the determination means 7 is provided for outputting a gas leak detection signal when the flow rate difference d is greater than or equal to a predetermined value X. Further, the configuration of claim 2 is as shown in FIG. , The sum S ′ of the integrated values mi ′ of the gas flow rate mi of each dwelling unit for a certain period T and the integrated value M ′ of the original gas flow rate M are compared, and when the difference D is equal to or greater than a predetermined value X ′, a gas leak detection signal is given The output according to the third aspect is the above. The determination means 7 is configured so that a plurality of determination programs having different periods T and predetermined values X'can be executed in parallel. Further, the configuration of claim 4 is, as shown in FIG. 5, the original gas flow rate. Data of M (or M ′) and flow rate difference d (or D) is stored, a relationship curve between the original gas flow rate M and flow rate difference d is created from these data, and this relationship curve is updated at regular intervals. Then, an error correction means 8 is provided to use this as an offset for gas leak measurement.

[0006]

The electronic gas meter 5 usually provided in each dwelling unit 2 uses a microcomputer to measure the amount of gas used in each dwelling unit, leaks gas in the dwelling unit 2, forgets to turn off the gas burner, and produces raw gas. The present invention utilizes these dwelling unit gas meters 5 and also shares a large-capacity gas meter with the same structure as the original gas meter 6 while detecting the discharge of gas, disconnection of gas pipe, etc. Installed near the inlet of the pipe 3, this original gas meter 6
The determination unit 7 or the error correction unit 8 is realized by adding the program of the microcomputer of 1., and the total S of the dwelling unit gas flow rate values mi measured by each dwelling unit gas meter 5 and the original gas meter 6 are measured. It compares the original gas flow rate value M, and when the difference d is greater than or equal to a predetermined value X, it determines the gas leak and outputs a detection signal. It is possible to shut off the gas supply, thereby preventing accidents such as gas poisoning and gas explosion.

Further, as in claim 2, the dwelling unit gas integrated value m obtained by integrating the dwelling unit gas flow rate mi for each fixed period T
The determination means 7 may be formed so as to compare the sum S ′ of i ′ and the original gas integrated M ′ value obtained by integrating the original gas flow rate M, and output a gas leak detection signal when the difference D is equal to or greater than a predetermined value X. If so, it is possible to detect gas leaks with higher accuracy and reduce malfunctions. Further, as in claim 3, if a plurality of determination programs having different periods T and predetermined values X ′ are executed in parallel, it is possible to cope with a large gas leak that requires an emergency and a small gas leak that requires accuracy. Therefore, high-quality gas leak detection is possible. Further, as in claim 4 or 5, the relation curve with respect to the original gas flow rate M or M ′ of the difference d or D in the period in which no gas leak occurs is previously set. If the error correction means 8 for correcting the predetermined values X and X ′ based on the obtained value is provided, the detection accuracy can be further improved.

[0008]

1 to 3 show an embodiment of the present invention. Generally, gas is supplied to each dwelling unit 2 of the housing complex 1 through a common pipe 3 as shown in FIG. 1, and each dwelling unit 2 is provided with an electronic dwelling unit gas meter 5, respectively. As shown in FIG. 2, the electronic dwelling unit gas meter 5 is formed by using a microcomputer 51, and a gas flow path 5a is operated by a meter measuring mechanism 52 for measuring a gas flow rate and an electric signal. A shutoff valve 53 that shuts off the gas flow path is provided. Further, in the control box 5b, a flow rate sensor 54 that magnetically detects the rotation of the meter measuring mechanism 52, a pressure switch 55 that detects a pressure change in the gas flow path 5a, a vibration detector 56 that detects an earthquake, and A substrate 57 on which the microcomputer 51 is mounted is stored. On the substrate 57, an abnormality display lamp (two-color display LED) 60, a test switch 61, a cutoff switch 62, a communication I / O circuit 63, a sensor I / O circuit 64, a pressure switch input circuit 65, a vibration detector input circuit. 6
6, flow rate pulse input circuit 67, shutoff valve I / O circuit 68,
A voltage drop determination circuit 69 or the like for determining the voltage drop of the lithium battery 70 is provided.

The present invention utilizes the function of the dwelling unit gas meter 5 as it is, and the original gas meter 6 newly installed is also scaled up in the gas flow path 5a and the meter lightweight mechanism 52, but other configurations are the dwelling unit. It is almost the same as the gas meter 5. In any of the gas meters 5 and 6, the rotation (gas flow rate) of the blades of the meter metering mechanism 52 is detected by the flow rate sensor 54, and the detected pulse signal is input to the microcomputer 51 via the flow rate pulse input circuit. In the microcomputer 51, the gas flow rate value obtained by counting the flow rate pulse and the pressure sensor 5
Based on the 5 outputs, the vibration detector 56 outputs, the states of the test switch 61 and the cutoff switch 62, various functions are calculated (security function, integrating function, telemeter function).

The gas leak detection apparatus according to the present invention uses the gas meters 5 and 6 configured as described above, and the original gas meter 6 is provided at the entrance of the common pipe 3 and the dwelling unit measured by each dwelling unit gas meter 5 The gas flow rate and the source gas flow rate measured by the source gas meter 6 are compared to determine a gas leak, and a determination means 7 for outputting a gas leak detection signal is provided. In the embodiment shown in FIG. , The total S of the dwelling unit gas flow rate values mi measured by each dwelling unit gas meter 5, and
The original gas flow rate value M measured by the original gas meter 6 is compared, and the difference d is a predetermined value X (for example, 3 liters /
In the above case, the determination means 7 is formed so as to output the gas leak detection signal. The original gas meter 6 is provided on each floor or each building depending on the scale of the housing complex 1.

Next, the operation will be described. Now Figures 1-3
In the case where no gas leak occurs in the common pipe 3, the total S of the dwelling unit gas flow rate values mi measured by the dwelling unit gas meters 5 is almost equal to the original gas flow rate value M measured by the source gas meter 6. Are equal. Therefore, the difference d becomes equal to or less than the predetermined value X set in consideration of the measurement error of the dwelling unit gas meter 5, and the determination unit 7 does not output the gas leak detection signal. When a gas leak occurs in the common pipe 3, the original gas flow rate value M measured by the original gas meter 6 is higher than the total S of the dwelling unit gas flow rate values mi measured by the respective dwelling unit gas meters 5. The amount of leakage increases. The judging means 7 judges that a gas leak has occurred when the difference d becomes equal to or larger than a predetermined value X, and outputs a gas leak detection signal.

Further, the main valve 9 provided at the inlet of the common pipe 3 is provided with an automatic shut-off means 9a which performs a closing operation upon receiving a gas leak detection signal, so that an accident caused by a gas leak can be prevented. To prevent. If this main valve 9 is integrated with the main gas meter 6, the structure can be simplified.
Further, in practice, the determination means 7 is configured by adding the program of the microcomputer 51 of the original gas meter 6. Further, in the embodiment, the signal transmission between the determination means 7 and each dwelling unit gas meter 5 is wired via the communication I / O circuit 63 or the sensor I / O circuit 64. It is also possible to form this by a wireless transmission means to simplify the wiring work.

FIG. 4 shows another embodiment, in which the dwelling unit gas integrated value mi 'is obtained by integrating the dwelling unit gas flow rates mi during a certain period T (for example, 1 hour, 1 day, 1 week, 1 month, etc.).
Is compared with the original gas integrated value M ′ obtained by integrating the original gas flow rate M for the certain period T, and a gas leak detection signal is output when the difference D is greater than or equal to a predetermined value X ′. The determination means 7 is formed in the. The longer the period T is, the longer the time from the occurrence of leakage to the detection is, but the detection accuracy is improved accordingly. Therefore, if the determination programs of a plurality of different periods T are simultaneously executed in parallel, it is urgent. Gas leaks that require
Since small gas leaks can be detected with high accuracy, higher quality gas leak detection can be performed.

FIGS. 5 to 6 show still another embodiment, in which a change pattern of the flow rate difference d or D with respect to the original gas flow rate M or M'in a proper length period in which no gas leakage occurs. Is obtained as a relational curve representing the measurement error as shown in FIG. 6A, and an error correction means 8 for correcting the predetermined values X and X ′ based on the relational curve is provided. Thus, the malfunction due to the measurement error of each dwelling unit gas meter 5 is prevented, and the device of the present invention can be practically used. Generally, the magnitude and sign of the measurement error of each meter 5 differs depending on the individual meter, and the gas usage amount of each meter also differs depending on the user. Therefore, it is difficult to predict the error as a group of gas meters. However, there is a problem that the measurement error is buried in the accumulated error. On the other hand, the measurement error is large when the flow rate is small and decreases exponentially as the flow rate increases, as shown in FIG. There is a tendency, and the distribution of gas meters in a certain residential area and the pattern of gas usage of residents living there tend to show a certain tendency with almost no change over a certain period of time. Therefore, if this relational curve is obtained in advance and the means 8 for correcting the above predetermined value X or X ', that is, the gas leak detection level is provided, the gas leak detection performance can be improved.

Even if a standard relational curve theoretically obtained from the average error of the gas meter is used as the error correction means 8, a certain degree of accuracy can be achieved, but the actual installed gas meter is also shown in FIG. Much higher accuracy can be achieved by actually measuring the relationship curve as shown. Also, even when actually measuring, using the relationship curve obtained by measuring only once at the time of installation will change the tendency of error due to moving residents, adding gas equipment, or aging of instruments, etc.
The accuracy may decrease. Therefore, in this embodiment, data of the original gas flow rate and the total dwelling unit gas flow rate for every day or every week as shown in FIG. 6B are accumulated, and from this data, the original gas flow rate as shown in FIG. M and flow rate difference d
A relationship curve with is created, and this relationship curve is updated at regular intervals, and this is used as an offset for gas leak measurement in the next measurement period. The leak information can be detected.

To specifically obtain the relationship curves shown in FIGS. 1B to 1A, for example, the total dwelling unit gas flow rate S is read and accumulated as data each time the value of the original gas flow rate M increases or decreases by 1 cubic meter per hour. When a plurality of d's are obtained for the same original gas flow rate M, the accuracy may be increased by taking the average. Further, when obtaining a relationship curve of D with respect to the integrated value M ′ for a certain period (one day, one week, etc.) as shown in FIG. 7C, it is necessary to accumulate data of the integrated value D for one day or one week. is there. In this case, it takes, for example, about one year to accumulate the data of the entire change width of the original gas flow rate M ′. Therefore, in order to shorten this cycle, the average value D'of D for a certain source gas flow rate M '(for example, 50 cubic meters) is measured at regular intervals, and the standard value is passed through the point (M', D '). It is also possible to adopt a simplified method of translating the pattern.

[0017]

As described above, the gas leak detection device according to the present invention has the sum S of the dwelling unit gas flow rate values mi measured by each dwelling unit gas meter 5 and the original gas flow rate value measured by the source gas meter 6. M is compared, and when the difference d is greater than or equal to a predetermined value X, gas leakage is determined and a detection signal is output, so that the occurrence of gas leakage is quickly detected, and a notification or gas supply is shut off. Therefore, accidents such as gas poisoning and gas explosion can be prevented in advance.

Further, the sum of the dwelling unit gas integrated values obtained by integrating the dwelling unit gas flow rates for a certain period of time is compared with the original gas integrated value obtained by integrating the aforesaid fixed period gas flow rates. At this time, if the determination means is formed so as to output the gas leak detection signal, the gas leak can be detected more reliably, malfunctions can be reduced, and the predetermined value can be corrected based on the change pattern of the past difference. Providing a correction means that has the effect of further improving the detection accuracy.

Furthermore, if an automatic shut-off means for closing the main valve provided at the entrance of the common pipe with the gas leak detection signal is provided, the gas supply can be automatically stopped when the gas leak is detected.
Furthermore, if the original gas meter and the original valve are integrated, the configuration can be simplified and the installation work can be facilitated. Furthermore, if the signal transmission between the determination means and the original gas meter and each dwelling unit gas meter is formed by the wireless transmission means, wiring work becomes unnecessary and the installation work can be greatly simplified, and the determination means can be used as the original meter. If integrated, there is an effect that the configuration can be further simplified.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part of the above.

FIG. 3 is an operation explanatory diagram of the above.

FIG. 4 is an operation explanatory diagram of another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of still another embodiment.

6A is a graph showing an example of an error correction curve, FIG.
(B) is a graph showing a change in gas flow rate, and (c) is a graph showing another example of an error correction curve.

[Explanation of symbols]

1 housing complex 2 dwelling units 3 common piping 5 dwelling unit gas meter 6 yuan gas meter 7 Judgment means 8 Correction means 9 yuan dialect 9a Automatic shutoff means

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Claims (5)

(57) [Claims] 1. An electronic dwelling unit gas meter is provided in each dwelling unit, and an electronic original gas meter is provided near the entrance of the common pipe, and the total of the dwelling unit gas flow rate measured by each dwelling unit gas meter and the original gas meter are used. A gas leak detection device for a common pipe, comprising: a determination unit that compares the measured original gas flow rate and outputs a gas leak detection signal when the difference between the flow rates is a predetermined value or more. 2. A determination means for comparing a total of integrated values of gas flow rates of respective dwelling units for a certain period of time with an integrated value of original gas flow rates and outputting a gas leak detection signal when the difference in the flow rates is a predetermined value or more. The gas leak detection device for a shared pipe according to claim 1, characterized in that. 3. The gas leakage detection device for a shared pipe according to claim 2, further comprising a determination unit that executes a plurality of determination programs having different lengths of the certain period in parallel. 4. The error correction means for correcting the predetermined value according to a relationship curve between the original gas flow rate and the error of the total dwelling unit gas flow rate, which has been obtained in advance.
Gas leak detection device for shared piping as described. 5. The data collected for gas leak detection is stored, a relationship curve between the original gas flow rate and the flow rate difference is created from these data, and the relationship curve is updated at regular intervals. The gas leak detection device for a shared pipe according to claim 4, further comprising an error correction means for correcting the predetermined value.