JP3273847B2 - Gas leak 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 leak detecting device for detecting a gas leak from a supply pipe in a gas supply system for supplying gas to a gas meter through a supply pipe.

[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. Thus, leakage in the pipe, unnatural gas outflow, and the like are detected, accidents are prevented, and safety is assured.

FIG. 7 shows a schematic configuration of a conventional gas supply system for general households. The gas meter 1 is disposed in the vicinity of the house 2, and a main pipe 3 and a supply pipe 4 buried underground are provided at a gas inlet of the gas meter 1.
The gas is supplied through the. An outlet of the gas meter 1 is connected to each gas appliance inside the house 2 through a supply pipe 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 could be automatically detected by the gas meter 1, Gas leaks from the buried gas pipe (supply pipe 4) on the premises could not be detected by the gas meter 1. Therefore, gas leaks have been detected by methods such as a patrol person confirming by odor or the like at the time of periodic security patrol once every three years, a meter reader noticing by odor at meter reading, and a consumer noticing 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.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a gas leak that can automatically and early detect a gas leak in a supply pipe leading to a gas meter with a simple configuration. It is to provide a detection device.

The gas leak detecting device according to the first aspect is applied to a gas supply system that supplies gas to a gas appliance via a gas meter, and is provided in a gas flow path on the upstream side of the gas meter. and Fuetai for transmitting a sound wave in response to the passage of gas is provided, the whistle is provided in the gas meter
Sound wave receiving means for receiving sound waves generated from the body , converting the electric waves into electric signals, and outputting the electric signals; gas flow detecting means provided in the gas meter for detecting a gas flow rate; and a gas flow path on the upstream side of the gas meter. First storage means in which data indicating a relationship between gas flow rate data output from the gas flow rate detection means and sound wave data output from the sound wave reception means in a normal time when there is no gas leakage is stored in advance; A second storage unit in which data indicating a relationship between the gas flow rate data output from the detection unit and the sound wave data output from the sound wave reception unit is sequentially stored for each unit time, and stored in the second storage unit; The data obtained is compared with the normal data stored in the first storage means in advance, and a gas leak from the gas flow path on the upstream side of the gas meter is detected based on the comparison result. And a scan leakage detection means.

In this gas leak detection device, when gas flows in the gas flow path on the upstream side of the gas meter, a sound wave is transmitted from the whistle body, and the sound wave is received by the sound wave receiving means in the gas meter via the gas flow path. You. The received sound wave data is sequentially stored in the second storage means for each unit time together with the flow rate data detected by the gas flow rate detection means. The gas leak detecting means compares the data stored in the second storage means with the normal data stored in the first storage means in advance, and, based on the comparison result, the gas flow on the upstream side of the gas meter. Detect gas leaks from roads.

[0010]

[0011]

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

FIG. 1 shows a schematic configuration of a gas supply system to which a gas leak detecting device according to one embodiment of the present invention is applied. This gas supply system converts a gas a supplied through a main pipe or a branch pipe (hereinafter referred to as a main pipe) 10 buried in the ground into a supply pipe (a lamp inner pipe) partially buried in the ground. ) 20 to the gas meter 30, and the flow rate is measured by the gas meter 30, and then supplied to a gas appliance (not shown) in each home via a supply pipe (including a lamp outer pipe) 40. is there.

A branch 50 called service cheese is provided between the main pipe 10 and the supply pipe 20. In this branch 50, the gas a is supplied to the gas meter 3 for each household.
It branches to 0. A whistle body 60 as a sound wave transmitting means is disposed inside the branching section 50, and the whistle body 60 transmits a sound wave as the gas a passes. The sound wave transmitted from the whistle body 60 is supplied to the supply pipe 20.
Is transmitted to the gas meter 30 via the tube wall and the internal gas flow path. The supply pipe 20 is made of, for example, a metal such as iron or a resin such as polyethylene.

The gas meter 30 is provided with a safety function using a microcomputer. Inside the gas meter 30, a gas inlet 31 and a gas outlet 3
2 is provided. The gas flow path 33 receives a sound wave transmitted from the whistle body 60 via the supply pipe 20 in order from the gas inlet 31 side, and converts the microphone into an electric signal. And a gas flow meter 36 for measuring the flow rate of the gas passing through the gas flow path 33. Also,
An alarm lamp 35 is provided on the front surface of the gas meter 30 for notifying by flashing or lighting a gas leak alarm (to be described later) (FIG. 3). In addition, you may make it alert | report by audio | voice instead of the warning lamp 35. FIG.

The gas meter 10 is provided with a control section 37 for inputting output signals of the microphone 34 and the gas flow meter 36 to control the alarm lamp 35.

FIG. 2 is a block diagram showing the configuration of the control unit 37 and its periphery in the gas meter 30 of the present embodiment.
The control unit 37 includes a CPU (Central Processing Unit) 70, an RO
An M (read only memory) 71, a RAM (random access memory) 72, a clock 73 for time measurement, and an input / output port 74 are connected to each other by a bus 75. A drive circuit 75 for driving the alarm lamp 35 is connected to the input / output port 74 in addition to the gas flow meter 36 and the microphone 34 described above. In this control unit 37, the CPU 70
By executing a program stored in the ROM 71 using the AM 72 as a working area, a safety function such as detection of gas leakage in the supply pipe 20 on the upstream side of the gas meter 30 is realized.

FIG. 3 is a functional block diagram showing the function of the gas leak detection device of the present embodiment. As shown in this figure, the gas leak detection device is provided in a gas flow path leading to the gas meter 30 and transmits sound waves of different types (wavelengths or amplitudes) in accordance with the gas flow rate; A sound wave receiving unit 81 provided in the gas meter 30 for receiving a sound wave transmitted from the sound wave transmitting unit 80, converting the sound wave into an electric signal, and outputting the electric signal; a gas flow detecting unit 82 provided in the gas meter 30 for detecting a flow rate of the gas a; It has. The sound wave transmitting means 80 includes the whistle body 60 shown in FIG.
1 is realized by the microphone 34, and the flow rate detecting means 82 is realized by the gas flow meter 36, respectively.

The gas leak detecting device of the present embodiment further includes gas flow data output from the gas flow detecting means 82 and output from the sound wave receiving means 81 in a normal state where there is no gas leak from the supply pipe 20 such as when a new pipe is installed. The first storage means 83 in which data indicating the relationship with the sound wave data to be stored is stored, and the relationship between the gas flow rate data output from the gas flow rate detection means 82 and the sound wave data output from the sound wave receiving means 81 is shown. Second storage means 84 in which data is sequentially stored for each unit time
And the data stored in the second storage means 84 are compared with the normal data stored in the first storage means 83 in advance. Gas leak detecting means 8 for detecting gas leaks
5 and an alarm unit 86 for issuing an alarm when the gas leak detection unit 85 detects a gas leak. The first storage unit 83 and the second storage unit 84 are both realized by the RAM 72, the gas leak detection unit 85 is realized by the control unit 37, and the alarm unit 86 is realized by the display lamp 35, the drive circuit 75, and the control unit 37.

FIGS. 4 and 5 show the sound wave transmitting means 8 respectively.
This represents a specific configuration of the whistle body 60 as 0.
The whistle body 60 has a cylindrical whistle body 61 formed of, for example, a resin such as polyethylene. The whistle body 61 is disposed inside the branch portion 50 along the longitudinal direction of the supply pipe 20, and is fixedly supported on the inner wall of the branch portion 50 via support rods 65a and 65b. One end opening (gas inlet 62) of the whistle body 61 faces a position where the gas flowing from the main pipe 10 changes direction. On the other hand, the other end opening (gas outlet 63) of the whistle body 61 is connected to the supply pipe 20.
Is opposed to the gas inlet 21. A gas branch port 64 is formed on the upper wall surface of the whistle body 61. A part of the gas a flowing from the gas branch port 64 toward the supply pipe 20 as shown by a solid line in FIG. It blows out as shown by.

That is, in the whistle body 60, the gas a supplied to the gas meter 30 with a constant pressure passes through the whistle body 61 as shown by a solid line in FIG. Emits a sound, that is, a sound wave b having a wavelength and an amplitude corresponding to the flow rate by blowing out from the gas branch port 64. Although this sound wave b is attenuated on the way, it is transmitted through the internal space of the supply pipe 20 and received by the microphone 34 in the gas meter 30. Here, a hole 20a is opened in the wall surface of the supply pipe 20 as shown in FIG. 1 due to the aging of the pipe and the like, and when gas leaks through this hole 20a, the gas flow rate fluctuates and the sound wave b is also generated.
Leak outside through 0a. Therefore, the relationship between the gas flow rate data and the sound wave data detected by the gas meter 30 changes from the normal state, and the presence or absence of gas leakage can be detected based on the change.

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

In this gas leak detecting device, when the supply pipe 20 is healthy (ie, when there is no gas leak from the supply pipe 20), such as when a new pipe is installed, the gas flow rate detecting means 8 is set in advance.
Gas flow data and sound wave receiving means 8 output from
The relationship between each of the sound wave data output from 1 is stored in the first storage means 83 (step S100).

When the use of a gas appliance (not shown) is started, a predetermined sound wave is transmitted from the sound wave transmitting means 80 in accordance with the passage of the gas, and the transmitted sound wave is transmitted to the gas meter 30 via the supply pipe 20. Is done. And the gas flow rate detecting means 82
And the sound wave data is detected by the sound wave receiving means 81 (step S10).
1) Thereafter, data indicating the relationship between the gas flow rate data and the sound wave data is sequentially stored and stored in the second storage means 84 for each unit time (step S10).
2). The gas leak detection means 85 compares the current data stored in the second storage means 84 with the first storage means 83
Is compared with the normal data stored in the gas flow path (the supply pipe 2) on the upstream side of the gas meter 30 based on the comparison result.
It is determined whether or not gas leakage from 0) has occurred (step S103).

When a gas leak is detected by the gas leak detecting means 85 (step S103; Y), the alarm means 86 drives the alarm lamp 35 to notify an alarm (step S104).

As described above, in the gas leak detection device of the present embodiment, the whistle body 60 is disposed at the branch portion 50 between the main pipe 10 and the supply pipe 20, and the supply pipe 20 generated from the whistle body 60 is connected to the whistle body 60. The sound wave reaching the gas meter 30 through the microphone 3
4, the gas meter 30 automatically detects a gas leak in the supply pipe 20 extending from the branch portion 50 to the gas meter 30, and can operate the safety device. That is, instead of detecting the odor of the gas which is easily diffused as in the conventional case, the change in the reception state of the sound wave is detected, so that the gas leak can be always detected, and the early detection is possible. In addition, even a small amount of gas leakage can be detected, and the gas meter 3
The safety function of No. 0 is further improved, and occurrence of a gas accident can be prevented.

A whistle body 60 used as sound wave transmitting means
Can be easily realized because of its simple structure.

The present invention has been described with reference to the embodiments.
The present invention is not limited to the above-described embodiment, and can be variously modified without changing the gist thereof. For example, in the above embodiment, the whistle body 60 shown in FIG. 4 has been described as the sound wave transmitting means, but the size, shape, material, position, and the like are arbitrary, and the point is generated in accordance with the flow rate of the gas a. Any sound can be used as long as it changes. The sound wave transmitting means is not limited to the whistle body 60, but may be any other means. However, it is desirable that the sound wave transmitting means can mechanically transmit sound waves in consideration of explosion protection.

As described above, according to the gas leak detection device of the present invention, the whistle body is provided in the gas flow path on the upstream side of the gas meter, and the sound wave transmitted through the gas flow path is transmitted. Since the gas leak is received by the sound wave receiving means and the change in the received sound wave is detected to detect the gas leak, the gas leak on the upstream side of the gas meter can be detected early and automatically, and a small amount of gas can be detected. Leakage can be detected, and the safety function of the gas meter is further improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining a gas supply system to which a gas leak detection device according to one embodiment of the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of a control unit in the gas leak detection device of FIG.

FIG. 3 is a block diagram for explaining a function of the gas leak detection device of FIG. 1;

FIG. 4 is a cross-sectional view illustrating a configuration of a whistle body used in the gas leak detection device of FIG.

FIG. 5 is a sectional view taken along line AA of FIG. 5;

FIG. 6 is a flowchart for explaining the operation of the gas leak detection device of FIG. 1;

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

[Explanation of symbols]

 Reference Signs List 10 main pipe 20 supply pipe 30 gas meter 34 microphone 35 alarm lamp 36 gas flow meter 37 control section 50 branch section (service cheese) 60 whistle body (sonic wave transmitting means)

Continuation of the front page (56) References JP-A-4-297994 (JP, A) JP-A-59-150320 (JP, A) JP-A-59-150321 (JP, A) JP-A-57-74635 (JP) , A) Actual opening 1975-78143 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/28 G01F 1/00 G01F 3/22

Claims (1)

(57) [Claims] 1. A gas supply system configured to supply gas to a gas appliance via a gas meter, a whistle body provided in a gas flow path on an upstream side of the gas meter and transmitting a sound wave in accordance with passage of the gas, A sound wave receiving unit provided in the gas meter for receiving a sound wave generated from the whistle body , converting the electric wave into an electric signal, and outputting the electric signal; a gas flow detecting unit provided in the gas meter for detecting a gas flow rate; A first stored data indicating a relationship between gas flow rate data output from the gas flow rate detection means and sound wave data output from the sound wave reception means in a normal state where there is no gas leakage from the upstream gas flow path. Storage means, and data indicating the relationship between the gas flow rate data output from the gas flow rate detection means and the sound wave data output from the sound wave reception means, for each unit time A second storage unit to be stored next; comparing data stored in the second storage unit with normal data stored in the first storage unit in advance; A gas leak detecting device, comprising: gas leak detecting means for detecting gas leak from an upstream gas flow path.