JP3267428B2 - Gas supply system abnormality detection device - 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 supply system abnormality detecting apparatus for detecting an abnormality such as gas leakage in a gas supply system.

[0002]

2. Description of the Related Art Generally, a household gas meter has a function of measuring a flow rate of gas passing therethrough, and detects a gas supply pressure by a pressure switch (pressure sensor) so that the pressure is measured when the gas is not used. If a decrease is detected, or if a gas flow of a predetermined amount or more is detected using a flow meter,
When the gas flow rate is detected for a predetermined period or more, the gas shutoff valve is driven to shut off the gas flow path.
Thereby, leakage in the piping, unnatural outflow of gas, and the like are detected, accidents are prevented beforehand, and safety is assured.

FIG. 7 shows a schematic configuration of a conventional gas supply system for general households. The gas meter 1 is arranged at a position close to the house 2, and gas is supplied to a gas inlet of the gas meter 1 through a main pipe 3 buried underground and a lamp outer pipe 4. The outlet of the gas meter 1 is connected to each gas appliance inside the house 2 through the lamp inner tube 5. A gas leak alarm 6 for issuing a gas leak alarm is provided inside the house 2.

In this conventional gas supply system, gas leakage from the gas meter 1 to the gas tap 7 provided for each gas appliance in the house 2 is detected by the gas leak detection mechanism of the gas meter 1. When the gas meter 1 detects a gas leak, the gas is shut off. In addition, if there is a gas leak in the room, the gas leak alarm 6 can detect and shut off the gas or issue an alarm.

[0005]

As described above, in the conventional system, the gas leak on the downstream side of the gas meter 1 can be automatically detected by the gas meter 1, but the gas leaks to the gas meter 1 by the customer. The gas meter 1 was unable to detect gas leaks from the buried gas pipes on the premises (the inner pipes 4 outside the lamps). For this reason, gas leaks have been detected by a method such as a patrol person confirming by odor or the like at the time of regular security patrol once every three years, a meter reader being noticed by odor at the time of meter reading, and a consumer being noticed by odor.

However, since a gas leaks outside, the gas diffuses, the conventional method cannot detect a small amount of the gas leak, and it takes a long time to find the gas leak. Was. In addition, at present, periodic inspections are performed only once every three years. Therefore, there is a problem that even if there is a gas leak, it may be used for a long time without being detected and lead to an accident.

The present invention has been made in view of such a problem, and an object of the present invention is to automatically and early detect an abnormality such as a gas leak in a gas supply system on the upstream side of a gas meter. It is an object of the present invention to provide a gas supply system abnormality detecting device.

[0008] In the gas supply system abnormality detecting device according to the first aspect, one end of the gas supply system crosses the main pipe buried underground.
Connected, the other end is connected to the gas meter,
Used for gas supply system with lamp outer tube buried underground
It is one which need a pressure variation generating means for generating a pressure fluctuation in the gas flow path which passes through the gas in the gas supply system, a wave lamp outside the tube by the generated pressure fluctuations by the pressure fluctuation generating means Pressure fluctuation detecting means for detecting a pressure fluctuation due to a reflected wave generated by reflection at the pressure, storage means for storing data of the pressure fluctuation detected by the pressure fluctuation detecting means when the gas supply system is normal, An abnormality determining means for comparing the data of the pressure fluctuation detected by the fluctuation detecting means with the data of the pressure fluctuation stored by the storage means, and determining an abnormality of the gas supply system based on the comparison result.

In this apparatus for detecting an abnormality in the gas supply system, the pressure fluctuation is generated in the gas flow path by the pressure fluctuation generating means, and the pressure fluctuation due to the reflected wave generated by the wave due to the pressure fluctuation being reflected in the gas supply system. Is detected by the pressure fluctuation detecting means. The data of the pressure fluctuation detected by the pressure fluctuation detecting means when the gas supply system is normal is stored by the storage means. Then, the abnormality determining means compares the data of the pressure fluctuation detected by the pressure fluctuation detecting means at the time of the inspection with the data of the pressure fluctuation stored by the storage means, and determines an abnormality in the gas supply system based on the comparison result. .

According to a second aspect of the present invention, there is provided a gas supply system abnormality detecting device, wherein the pressure fluctuation generating means and the pressure fluctuation detecting means in the gas supply system abnormality detecting device according to the first aspect of the present invention are configured to detect a gas passing through a gas passage. It is provided in a gas meter that measures the flow rate.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a gas supply system including a gas supply system abnormality detecting device according to one embodiment of the present invention. This gas supply system supplies a gas a supplied through a main pipe or a branch pipe (hereinafter referred to as a main pipe) 10 buried in the ground to a lamp outer pipe 11 also partially buried in the ground.
Through the gas meter 20 and the gas meter 2
After measuring the flow rate at 0, the gas is supplied to gas appliances (not shown) in each household via the inner tube 12 within the lamp.

The gas meter 20 is provided with a safety function using a microcomputer. Inside the gas meter 20, a gas inlet 21 and a gas outlet 2 are provided.
2 and a gas pipe 23 constituting a part of a gas flow path in the gas supply system is provided. The gas pipe 23 is provided with a speaker 24 as a pressure fluctuation generating means for generating pressure fluctuation in the gas flow path in order from the gas inlet 21 side.
And a microphone 25 as pressure fluctuation detecting means for detecting a pressure fluctuation caused by a pressure fluctuation wave generated by the speaker 24, that is, a reflected wave generated by reflection of a sound wave in the gas supply system, and a gas pipe 23 to be shut off. And a gas flow meter 27 for measuring the flow rate of the gas passing through the gas pipe 23.

The gas meter 20 is provided with a control unit 30 for inputting output signals of the microphone 25 and the gas flow meter 27 and for controlling the speaker 24 and the gas cutoff valve 26.

FIG. 2 shows a control unit 30 of the gas meter 20.
FIG. 2 is a block diagram showing a configuration of a peripheral device. The control unit 30 includes a CPU (central processing unit) 31, a ROM (read only memory) 32, a RAM (random access memory) 33, a clock 34 for time measurement, and an input / output port 35. Are connected to each other by a bus 36. The input / output port 35 has a speaker 2 in addition to the gas flow meter 27 and the microphone 25 described above.
4, a drive circuit 38 for driving the gas cutoff valve 26, and a drive circuit 40 for driving an alarm lamp 39 provided in the gas meter 20 are connected. In the control unit 30, the CPU 31
By executing the program stored in the ROM 32 using the M33 as a working area, the gas meter 2
The function of detecting an abnormality such as a gas leak in the gas supply system (supply pipe 11) on the upstream side of 0 is realized.

FIG. 3 is a functional block diagram showing the function of the apparatus for detecting abnormality of the gas supply system of the present embodiment. As shown in this figure, the abnormality detection device of the gas supply system includes a pressure fluctuation generating means 41 for generating a pressure fluctuation in a gas flow path, and a wave generated by the pressure fluctuation generated by the pressure fluctuation generating means 41. A pressure fluctuation detecting means for detecting a pressure fluctuation due to a reflected wave generated by reflection in the system; and a first for storing data of the pressure fluctuation detected by the pressure fluctuation detecting means when the gas supply system is normal. Storage means 43
A second storage means 44 for storing data of the pressure fluctuation detected by the pressure fluctuation detecting means 42 at the time of the inspection; and a pressure fluctuation data stored by the first storage means 43 and the second storage means 44. Abnormality determining means 45 for comparing the stored pressure fluctuation data and determining an abnormality in the gas supply system based on the comparison result;
And alarm means 46 for notifying an alarm when the abnormality of the gas supply system is determined by 5.

The pressure fluctuation generating means 41 is realized by the speaker 24, and the pressure fluctuation detecting means 42 is realized by the microphone 25. The first storage unit 43 and the second storage unit 44 are realized by the RAM 33, and the abnormality determination unit 45 is realized by the control unit 30,
The warning means 46 is realized by a warning lamp 39.

Next, the operation of the gas supply system abnormality detecting device according to the present embodiment will be described with reference to the flowchart shown in FIG.

In this gas supply system abnormality detecting device, first, when the gas supply system is normal, such as when the gas meter 20 and the pipe are newly installed, the pressure fluctuation generating means 41 generates a pulse-like pressure fluctuation (pulse sound). Then, a sound wave due to the pressure fluctuation is emitted toward the inner tube 11 outside the lamp (step S1).
01). This sound wave is reflected at the connection between the lamp outer tube 11 and the main tube 10, and returns to the gas meter 20 side. The pressure fluctuation due to the reflected wave is detected by the pressure fluctuation detecting means 42 (Step S102). Then, the data of the pattern of the pressure fluctuation in the normal state detected by the pressure fluctuation detecting means 42 is stored in the first storage means 43 (step S103). FIG. 5 shows an example of a pressure fluctuation pattern in the normal state.

Next, at the time of inspection performed at a predetermined cycle, a pulse-like pressure fluctuation (pulse sound) is generated by the pressure fluctuation generating means 41, and a sound wave due to this pressure fluctuation is generated by the lamp inner tube 1.
1 (step S104), and a pressure fluctuation caused by a reflected wave generated by reflection of the sound wave in the gas supply system is detected by the pressure fluctuation detecting means 42 (step S104).
105). Then, the data of the pressure fluctuation pattern detected by the pressure fluctuation detecting means 42 is stored in the second storage means 44 (step S106).

FIG. 6 shows an example of a pressure fluctuation pattern due to a reflected wave when there is an abnormality in the gas supply system. In the example shown in this figure, a fluctuation (hereinafter referred to as a transient phenomenon) 51 that does not appear in a normal state appears before a reflected wave reflected at a connection portion between the lamp outer tube 11 and the main tube 10. This transient phenomenon 51 is due to corrosion leakage of the lamp inner tube 11. When the gas component changes, the sound speed changes, so that the pressure fluctuation pattern moves in the time axis direction with respect to the normal state. Therefore, by comparing the pattern of the pressure fluctuation at the time of the inspection with the pattern of the pressure fluctuation at the normal time, it is possible to determine an abnormality in the gas supply system such as corrosion leakage, water entry, and a change in gas components.

In this embodiment, the abnormality determining means 45
A matching operation is performed between the pressure fluctuation pattern at the time of inspection stored by the second storage means 44 and the normal pressure fluctuation pattern stored by the first storage means 43 to determine the degree of matching between the two patterns ( Step S107). In the matching operation, for example, a difference between sound pressures in both patterns is obtained at each time, and a sum of absolute values of the differences and a sum of squared differences are obtained. The smaller the sum of the absolute values of the differences or the sum of the squared differences, the greater the degree of matching between the two patterns. Abnormality determination means 45
Determines whether there is an abnormality in the gas supply system based on the degree of matching between the two patterns (step S108). If there is no abnormality (N), the process returns to step S104. If there is an abnormality (Y), the abnormality detection device of the gas supply system
An alarm is notified by the alarm means 46 (step S10).
9) The gas flow path is cut off by the gas cutoff valve 26, and the operation is terminated. In addition, as a method of the alarm, the alarm lamp 39
Not limited to the above, a buzzer may be used, and by shutting off the gas flow path by the gas shutoff valve 26,
It is also possible to forcibly urge the gas user to report an abnormality.

The gas meter 20 detects the normal pressure fluctuation pattern (step S in FIG. 4).
If a reset switch for starting 101 to S103) is provided, a normal pressure fluctuation pattern can be reset when the gas supply system is changed due to remodeling or the like.

As described above, according to the gas supply system abnormality detecting device of the present embodiment, a sound wave is periodically emitted toward the upstream side of the gas meter 20 in the gas flow path.
Since a pattern of a reflected wave generated by reflection in the gas supply system is detected and an abnormality in the gas supply system is detected based on a change in the diameter of the pattern, a gas leak in the gas supply system on the upstream side of the gas meter 20 is detected. And the like can be automatically and early detected.

Further, in the gas supply system abnormality detection apparatus of the present embodiment, the abnormality is detected without shutting off the gas, so that the abnormality can be detected without stopping the gas supply to the customer.

The present invention is not limited to the above embodiment,
For example, in the embodiment, all the components of the abnormality detection device of the gas supply system are provided in the gas meter 20, but all or some of these components are provided separately from the gas meter 20 in the vicinity of the gas meter 20. You may. For example,
A speaker 24 and a microphone 25 are arranged in the lamp outer tube 11 in the vicinity of the gas meter 20, and the gas meter 20
May be connected to the control unit 30.

The wave due to the pressure fluctuation is not limited to the audible sound, but may be a compression wave having a lower or higher frequency than the audible sound. Further, the pressure fluctuation generating means is not limited to the speaker 24, and may be a proportional valve or an on-off valve which generates a compression wave by opening and closing the gas flow path in a short time.

In the embodiment, a sound wave is emitted toward the upstream side of the gas meter 20 to detect an abnormality in the gas supply system on the upstream side of the gas meter 20.
It is also possible to emit a sound wave toward the downstream side of the gas meter 20 and detect an abnormality in the gas supply system downstream of the gas meter 20. Therefore, according to the present invention, it is possible to detect an abnormality in the gas supply system from the main pipe to the gas tap in the house.

[0029]

As described above, according to the gas supply system abnormality detecting device of the present invention, the pressure fluctuation generating means for generating the pressure fluctuation in the gas flow path, and the pressure generated by the pressure fluctuation generating means Pressure fluctuation detecting means for detecting pressure fluctuation due to reflected waves generated by reflection of waves due to fluctuations in the gas supply system, and data of pressure fluctuation detected by the pressure fluctuation detecting means when the gas supply system is normal The data of the pressure fluctuation detected by the pressure fluctuation detecting means at the time of inspection and the data of the pressure fluctuation stored by the storing means are compared by the abnormality determining means, and the result of the comparison is used for the gas supply system. Since abnormalities are determined, it is necessary to automatically and early detect abnormalities such as gas leakage in the gas supply system on the upstream side of the gas meter. An effect that can be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a gas supply system including a gas supply system abnormality detection device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control unit of the gas meter in FIG. 1 and its surroundings.

FIG. 3 is a block diagram for explaining a function of an abnormality detection device of the gas supply system of FIG. 1;

FIG. 4 is a flowchart for explaining the operation of the abnormality detection device for the gas supply system of FIG. 1;

FIG. 5 is a characteristic diagram showing an example of a pattern of pressure fluctuation in a normal state detected by the abnormality detection device of the gas supply system of FIG. 1;

FIG. 6 is a characteristic diagram showing an example of a pressure fluctuation pattern at the time of an abnormality detected by the abnormality detection device of the gas supply system of FIG. 1;

FIG. 7 is an explanatory diagram for explaining a conventional gas supply system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Main pipe 11 Lamp outer tube 20 Gas meter 24 Speaker 25 Microphone 26 Gas shutoff valve 30 Control part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01M 3/24 G01F 1/00 G01F 15/06 G01M 3/00 G01M 3/26

Claims (2)

(57) [Claims] 1. One end intersects with a main pipe buried underground.
And the other end is connected to the gas meter.
Gas supply with a lamp outer tube partially buried underground
A failure detection device of the system, the pressure fluctuation generating means for generating a pressure fluctuation in the gas flow path of gas passes in the gas supply system, the lamp wave due to pressure fluctuations generated by the pressure fluctuation generating means and pressure fluctuation detecting means for detecting a pressure variation due to the reflected wave generated by reflection in the outer and inner tubes, storage means for storing the data of the pressure variation of the gas supply system is detected by the pressure fluctuation detecting means when the normal And abnormality determination means for comparing the data of the pressure fluctuation detected by the pressure fluctuation detection means at the time of inspection with the data of the pressure fluctuation stored by the storage means, and determining an abnormality of the gas supply system based on the comparison result. An abnormality detection device for a gas supply system, comprising: 2. The gas supply according to claim 1, wherein said pressure fluctuation generating means and said pressure fluctuation detecting means are provided in a gas meter for measuring a flow rate of a gas passing through said gas flow path. System abnormality detection device.