JP3388576B2 - Gas leak detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas shutoff device.

[0002]

2. Description of the Related Art When a gas is stopped, a user operates a valve opening / closing switch of an operating unit to forcibly shut off a shutoff valve of a microcomputer gas meter, thereby ensuring a safe gas supply state during the gas stop. The function of keeping is used conventionally.

While the shutoff valve of the microcomputer gas meter is forcibly shut off while the gas is stopped, the gas leak is detected by the minute flow rate leak detecting means usually installed inside the microcomputer gas meter. It is common that the functions for

In other words, there is little need to detect gas leakage while the gas supply is cut off while gas usage is stopped, and the power consumption used for the detection operation and the like is reduced rationally. Since it is possible to support the use of the power supply battery for a longer period of time, the user operates the valve open / close switch of the operating unit to forcibly shut off the shutoff valve of the gas meter while the gas is not used. The operation of the gas leakage detection means normally installed inside the microcomputer gas meter is stopped.

The above-mentioned gas leakage detecting means generally operates a timer function during use of the gas, and when it is detected that the gas continuously flows for a predetermined time (for example, 30 days). It is determined that a gas leak has occurred. That is, unless the gas flow rate is considered to be 0 on the way, it is determined that gas leakage has occurred.

Therefore, during the above-described gas use stop, the timer function of the gas leakage detection means is temporarily stopped, and the user operates the valve opening / closing switch of the operating device again to open the shutoff valve this time. When returning to the state, the timer function of the gas leakage detection means is restored and the counting of the predetermined time is started again.

However, in the case of a microcomputer gas meter for commercial use, for example, almost no gas is supplied except when the shutoff valve is closed while the gas is stopped, that is, while the shutoff valve is open. It is normal that the usage state continues, and the gas flow rate rarely becomes zero. Therefore, in the case of a microcomputer gas meter that is used for such a business, while the shutoff valve is open and the gas is used, the timer function is always in operation. Even if the shutoff valve is closed in the middle of the process, if the shutoff valve is returned to the open state and the gas usage is measured after that, there is a problem that a gas leak is erroneously determined.

In order to avoid the above problems, it is possible to reset the timer every time the shutoff valve is closed, but this time, the shutoff valve is closed more than a certain frequency. If it becomes frequent, it will not be possible to detect it even though the gas leak is continuing, and in the opposite sense of the leak detection error, that is, if the gas leak occurs, it will be overlooked. There is a problem that mistakes occur.

Further, when the shutoff valve is closed to shut off the gas supply while the gas is stopped as described above, at least the gas flow before and after the shutoff valve is shut off. However, even if a gas leak really occurs, the gas flow caused by the gas leak does not flow. Therefore, even if the gas leak detection means is operated at this time, there is a problem that the occurrence of the gas leak cannot be found.

Furthermore, in order to avoid such a problem, it may be considered not to shut off the gas even when the gas is stopped, but the valve is kept open during the gas is stopped. It is not preferable to leave it because it poses a safety problem. That is, if the shutoff valve is opened for gas leak detection, the gas can be supplied while the gas is stopped, which tends to be overlooked.
When a gas leak occurs, the gas leak itself is promoted, and there is a problem that the risk is further increased.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a state in which a gas flow is detected even in a minute amount within a predetermined detection period such as 30 days. Gas has a function to detect a gas leak if it continues, and has a function to forcibly shut off the shutoff valve and stop counting the detection period when gas is stopped. Leak detection device,
Alternatively, in a gas leak detection device used in a microcomputer gas meter that has a similar function, the problem of erroneous determination of gas leak due to the continued counting of the detection period before and after stopping gas use can be resolved, ensuring accurate and reliable operation. Gas leakage can be determined, and the shutoff valve can be forcibly shut off during gas stoppage to maintain safety. In addition, the power consumption during that time can be reduced to almost zero to reduce power consumption. It is an object of the present invention to provide a gas leakage detection device that can meet the requirements for a longer-term use of a microcomputer gas meter.

[0012]

First, a gas leakage detection device of the present invention is provided with a gas supply pipe for conducting gas supplied from a gas supply source from the gas supply source to a gas consuming device on a downstream side. Gas flow detection means disposed in the middle and outputting at least one pulse corresponding to the flow of the gas to detect the flow of the gas; and a gas flow detection means disposed in the middle of the gas supply pipe to open or close the valve to detect the gas flow. A shutoff valve for stopping and conducting the flow, and a first time counting means for continuing the time count over a predetermined first detection period, the shutoff valve being in an open state only. A first time during which the time counting is continued, but the time counting is temporarily stopped during the period in which the shutoff valve is in the closed state, and the once stopped time is continued when the shutoff valve returns to the open state again. Coun Means and gas leakage occurs when the gas flow detection means continuously detects the gas flow without interruption over the first detection period counted by the first time counting means. If it is determined that the gas flow is stopped while the time count of the first detection period is continuing, the time count is stopped and the time count is reset to set the time count. In a gas leakage detection device having a gas leakage determination means for returning to a state in which counting can be newly started again from an initial value, a shutoff valve for sending a signal for controlling an open / closed state of the shutoff valve to control opening / closing of the shutoff valve. When a signal for controlling the shutoff valve to be closed is sent from the open / close control means and the shutoff valve open / close control means, from the time when the signal is received, from the first detection period. A shut-off valve standby shutoff control means for executing the valve closing operation after at least the elapsed time over a shorter second detection period,
When a signal for controlling the shut-off valve to be closed is sent from the shut-off valve opening / closing control means, from the time of receiving the signal, the time count of the second detection period is continued for the second detection period. And when at least one pulse corresponding to the state where the gas flow is not 0 is output from the gas flow detection means during the second detection period,
While the time counting by the first time counting means continues without being reset, the time counting is further continued for a third detection period while the shutoff valve is kept open, and the third detection period is continued. When at least one pulse is output from the gas flow detection means during the time counting of the above, it is determined that gas leakage has occurred, and the shutoff valve is shut off by the shutoff valve standby shutoff control means. The alarm generation means issues an alarm indicating that the gas leakage has occurred while the switch is closed.
If no one pulse is output during the time counting of the second detection period or the time counting of the third detection period, it is determined that no gas leakage has occurred. 1. Standby shutoff leakage determination means for resetting the time count of the time counting means 1 and closing the shutoff valve by the shutoff valve standby shutoff control means, and alarm generation means for issuing the alarm. It is a characteristic gas leakage detection device.

That is, the fact that the signal for controlling the shut-off valve to be in the closed state is sent from the shut-off valve opening / closing control means means that the safety is further ensured when the user temporarily stops using the gas. It means that the gas supply was forcibly cut off. In other words, in other words, the user has informed the gas leak detection device and the gas meter that the use of gas will be stopped for a while from the time when this signal is sent. Therefore, for a while from the time when the signal for controlling such a shut-off valve to be closed is sent, the gas corresponding to the general use of gas should be in a state of not flowing. That is, if there is no gas leakage during that time, the gas flow must be 0. In other words, if there is any gas flow for a while (because the shutoff valve is not yet closed) for a while after the signal for controlling the shutoff valve to be closed is sent, In that case, the probability of gas leakage is extremely high. On the contrary, if the gas flow = 0 continues without interruption for a while, it is possible to highly accurately determine that the gas leakage has not occurred.

Therefore, according to the present invention, when a signal for controlling the shut-off valve to be closed is sent, the standby shut-off leakage determination means continues for the second detection period from the time when the signal is received. And continues the set time count such as 60 minutes and outputs at least one pulse corresponding to the state where the gas flow is not 0 during the second detection period from the gas flow detection means. Since the gas flow was detected during this period when the gas flow should be 0 if it is normal, it is considered that there is a high probability that a gas leak has occurred, and the first time count is performed. While the time counting by the means continues without resetting, the time counting is further continued over the third detection period set to 60 minutes or the like, and at least one pulse is generated during the time counting during the third detection period. When the above-mentioned pulse is output from the gas flow detection means, it is determined that a gas leak has occurred, the shutoff valve is closed, and the gas leak has occurred. An alarm to that effect is generated by the alarm generation means.

On the other hand, when no pulse is output during the time counting of the second detection period or the time counting of the third detection period, gas leakage occurs at least during this period. Since it can be determined that the time has not occurred, the time count of the first time counting means is reset and the shutoff valve is closed after the time count is completed. Then, after that, the gas flow detection function, the gas leakage determination function, and the like are stopped to save power consumption, and the shutoff valve is kept closed to enter the so-called forced shutoff state at the time of stopping gas use.

In this way, it is possible to determine whether or not gas leakage has occurred during the second detection period and the third detection period by the standby cutoff leakage determination means. The necessity as to whether or not to continue the time count of the detection period of 1 can be determined with high validity.

That is, when one or more pulses are detected in each of the second detection period and the third detection period and it is determined that gas leakage has occurred, an alarm to that effect is issued. It is possible to reliably notify the user of the occurrence of gas leakage. Alternatively, a pulse was detected in the second detection period (ie a gas flow was detected) but a third
Even if no pulse was detected during the detection period, the need to continue counting the time during the first detection period after that was suspected of gas leakage was determined with high validity, and the shutoff valve was opened again. After restarting the gas supply and returning the gas supply, by continuing the counting of the time count of the first detection period, the warning of gas leak detection is continued after that and the occurrence of the gas leak is surely found. (Determination) is possible.

On the other hand, if no pulse is detected during either the second detection period or the third detection period, no gas leakage has occurred. Since it is determined with high probability (validity), in that case, after that, that is, after the shutoff valve is returned to the open state and the gas supply is restored, the continuation of the time count of the first detection period is There is no need to count more. On the contrary, if the continuation of the time counting of the first detection period is continued, the second detection
Although it is determined that the gas leakage does not occur in the detection period and the third detection period, it will be erroneously determined that the gas leakage has occurred after the counting is ended, which is inconvenient. is there. Therefore, in such a case, by resetting the time count of the first detection period, it is possible to prevent erroneous determination due to the subsequent time count continuation.

After the second detection period or the third detection period elapses, the shutoff valve is closed to ensure the safety during the gas use stop and the gas leakage detection function corresponding to the gas use stop. It is possible to enter a temporary stop state such as, and save power consumption during that time.

In this way, according to the present invention, it is judged that gas leakage has occurred when the state in which the gas flow is detected is small even within a predetermined detection period such as 30 days. A gas leak detection device having a conventional function, which has the function of forcibly shutting off the shutoff valve and stopping the counting of the detection period while the gas is stopped, or a function similar to that. In a gas leak detection device used in a microcomputer gas meter, it is possible to solve the problem of erroneous determination of gas leak due to the continuation of the detection period before and after gas usage is stopped, and to make an accurate and reliable determination of gas leak. In addition, the shut-off valve can be forcibly shut off during gas stoppage to maintain safety, and the power consumption during that time can be kept low to almost zero to reduce power consumption. It is possible to sufficiently cope with the demand for further long-term use of the microcomputer gas meter to achieve power.

As the gas flow detecting means, for example, a so-called membrane gas flow meter is used, and a gas flow rate measuring mechanism of a volumetric flow rate measuring system is used for every one cycle or half cycle of the volume change. A gas flow meter that outputs a pulse may be used. Alternatively, a method of outputting a pulse having a frequency or intensity corresponding to various fluid physical quantities that change in accordance with the flow velocity or flow rate of a gas flow, which is called a so-called guess method (or an estimation method in literature). That is, a differential pressure flow meter pressure method that measures the dynamic pressure due to the gas flow, an area flow rate measurement method that measures the viscous resistance of the gas flow, a turbine flow rate measurement method that measures the power of the gas flow to move the turbine blades, Vortex flow rate measurement method that measures the frequency of the vortex generated in the gas flow, and ultrasonic flow rate measurement gas flow meter that propagates ultrasonic waves in the gas flow and measures their propagation time or velocity etc. It can be suitably used as a flow detection means. Alternatively, it is also possible to use a thermal mass flow rate measuring method in which a heat ray is arranged in the gas flow and the temperature change before and after the heat ray is measured.

Needless to say, any device that outputs a pulse corresponding to a factor (physical quantity) relating to the flow velocity or flow rate of gas can be suitably used as the gas flow detecting means according to the present invention. Yes. Secondly, in the gas leakage detection device according to the first aspect of the present invention, at least the gas flow detection means, the shutoff valve, the first time counting means, and the gas leakage determination means are included in the gas leakage detection means. Any one is arranged in the middle of the gas supply pipe that conducts the gas supplied from the gas supply source to the gas consuming device on the downstream side from the gas supply source, and measures the integrated flow rate of the gas. The gas flow detecting means, the shutoff valve, the first time counting means, and the gas leakage determining means used in the gas meter are also used in combination.

That is, at least one or more of the shutoff valve, the gas flow detection means, the first time counting means, and the shutoff valve opening / closing control means used in the gas leakage detection device according to the first aspect. In all, the constituent parts used in the main part of the conventional so-called microcomputer gas meter can be suitably used as the corresponding constituent parts.

That is, as the shut-off valve, the shut-off valve provided in the gas meter is preferably used to stop the gas supply in order to avoid the danger when the conventional general gas leak is detected. Can be used. Further, as the gas flow detection means, a membrane volumetric flow meter or an ultrasonic estimation type flow meter (or an anemometer) is provided in a gas meter and is used to measure an integrated consumption flow rate of gas consumed by a user. For example, a general gas flow rate measuring means can be suitably combined and used. However, as this gas flow detection means, it is desirable that it is possible to detect a minute flow rate (or flow velocity) when a minute gas leak occurs. From this point, accurate detection of the minute flow rate is possible. It goes without saying that it is desirable to use a gas flow rate measuring means that uses a flow rate sensor or a flow rate sensor capable of performing the above.

Further, as the first time counting means and the shutoff valve opening / closing control means, those used in the conventional general microcomputer gas meter can be used in combination. By doing so, the gas leak detection device according to the present invention can be constructed easily, inexpensively and compactly in the microcomputer gas meter by using the components already provided in the conventional general microcomputer gas meter. .

Thirdly, the gas leakage detection device of the present invention is the gas leakage detection device according to the first or second aspect, wherein the shutoff valve opening / closing control means includes a valve opening / closing changeover switch as a command input interface. A shutoff valve opening / closing control means for sending a signal for controlling the opening / closing of the shutoff valve in response to an input using the valve open / close changeover switch, wherein the valve open / close changeover switch includes at least the shutoff valve and the gas flow detection The shutoff valve opening / closing control means is arranged at a position different from the main body of the gas leak detection device in which the means is arranged, and is connected to the main body of the gas leak detection device via transmission means. I am trying.

That is, the shutoff valve opening / closing control means outputs (outputs) a signal for controlling the shutoff valve from the closed state to the open state as a signal for controlling the opening / closing of the shutoff valve.
On the contrary, the so-called command input for sending (outputting) a signal corresponding to the operation when the user inputs a different operation when outputting a signal for controlling the open state to the closed state. The valve opening / closing switch used as an interface should be installed in or near the user's daily living area as much as possible, rather than being installed outdoors where the main body of the microcomputer gas meter or gas leak detection device is installed. The operation should be convenient for the user.

Therefore, the valve open / close changeover switch used as a so-called command input interface is located at a position different from the position where the main body of the microcomputer gas meter or the gas leakage detection device is installed, more preferably within the daily living area of the user. It may be installed in the living room. Then, the transmission / reception of a signal between the valve opening / closing switch installed in the user's living room and the main body of the gas leakage detection device is performed by using a transmission means such as a dedicated transmission wiring or a wireless communication means. Just do it.

In particular, when an existing shutoff valve is already installed in the gas meter, it is preferable to use this as the shutoff valve of the gas leakage detection device according to the present invention. If a valve opening / closing switch used as a command input interface for sending a signal to forcibly shut off the shutoff valve when gas is stopped is already installed, use the valve opening / closing switch already installed. It can be suitably used as the valve opening / closing switch according to the present invention.

As described above, if there are existing hardware resources or the like, they can be suitably used as the valve opening / closing changeover switch or the like according to the present invention. And since existing hardware resources are diverted in this way, it is not necessary to add a changeover switch or wiring as an instruction input interface, and the addition of such things makes the entire device complicated. Can be avoided.

Fourthly, in the gas leakage detection device according to any one of the first to third aspects, the standby-interruption-time leakage determination means is a pulse during the time counting of the second detection period. Is output, but if no one pulse is output during the time count of the third detection period, it is determined that the possibility of gas leakage cannot be ignored and the The gas leak detection device is characterized in that the time count of the time count unit 1 is a leak determination means at the time of standby interruption that is not reset.

That is, when a pulse is output during the time counting of the second detection period, but no pulse is output during the time counting of the third detection period, it is certain that Since the gas flow was not detected in the third detection period, it is considered that no gas leakage has occurred at that time, but since the gas flow was detected during the second detection period before that, Therefore, it is not always possible to ignore the possibility that a gas leak has occurred, and it may be possible to achieve more reliable gas leak detection by continuing to monitor gas leaks after the return of gas usage. Many.

Therefore, in order to deal with such a case, in the technique described in the fourth aspect, the standby cutoff leakage determination means outputs a pulse during the time counting of the second detection period. If no one pulse is output during the time counting of the detection period of 3,
The possibility that gas leakage has occurred cannot be ignored, and the time count of the first time counting means is not reset. As a result, the probability that more reliable gas leakage detection can be realized can be increased. However, the effect of increasing the probability that such reliable gas leakage detection can be achieved is that the second detection period or the third detection period and the first detection period have a trade-off of the actual time length, Since it depends greatly on the trade-off of the length of time that can be taken as the actual detection period, it is not preferable to take the detection period too long by pursuing accuracy too much,
On the contrary, if it is too short, only coarse detection can be performed, so it is needless to say that an optimum value can be set appropriately in consideration of the measurement rangeability of the gas flow detection means, etc. in actual quantitative setting of the time. Yes.

Fifthly, the gas leakage detection device of the present invention is the gas leakage detection device according to any one of the first to third aspects, wherein the standby cutoff leakage determination means is the second gas leakage detection device.
When at least one pulse is output during the time count of the detection period of 1, it is determined that gas leakage has occurred, and at that time, the time count of the first time count means is reset. Along with this, the shutoff valve standby shutoff control means closes the shutoff valve, and the standby shutoff leakage determination means issues an alarm indicating that the gas leakage has occurred by the alarm generation means.

That is, if even one pulse is detected in the second detection period, it may be determined immediately that gas leakage has occurred. However, when the pulse detection in the third detection period is omitted in this way, the determination accuracy tends to be rougher than in the case where the pulse detection in the third detection period is performed as described above. Needless to say. However, on the other hand, regarding the time during which the gas flow detecting means and the like are continuously operated until the state is completely shifted to the forced shutoff state, the pulse detection is continued until the above third detection period. Since it can be completed in a short time, the merit that it is possible to save the power consumption required for operations such as pulse detection during that time, and the transition to the complete valve cutoff state that completely corresponds to the gas usage stop from the above There is also an advantage that you can do it early.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a gas leakage detection device according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a main part of a gas leakage detection device according to the present invention.

In this gas leakage detection device, a gas supplied from a gas supply source (not shown) is connected to the gas supply pipe 1 which connects the gas from the gas supply source to a gas consuming device (not shown) on the downstream side. Arranged to correspond to the flow of gas,
When a gas flow is flowing, at least one pulse is output to detect the gas flow (in the present embodiment, a membrane gas flow meter is used).
A shutoff valve 102 arranged in the middle of the gas supply pipe 1 for stopping and conducting the flow of the gas by opening and closing the valve 2; and a predetermined first detection period T1 (T1 in the present embodiment). = 30 days), the first time counting means 103 for continuing the time counting, and the time counting is continued only during the period when the valve 2 of the shutoff valve 102 is in the open state, but the shutoff is performed. A first time period during which the time counting is temporarily stopped during the period in which the valve 2 of the valve 102 is in the closed state, and the time period that has been temporarily stopped is continued when the valve 2 of the shutoff valve 102 returns to the open state again. Counting means 103 and the first time counting means 10
In the case where the gas flow detection means 101 continuously detects the flow of the gas without interruption (that is, without the gas flow = 0 in the middle) over the first detection period counted by 3. Determines that gas leakage has occurred, and when the stop of the flow of the gas is detected while continuing the time counting of the first detection period T1, the time counting is stopped and the time counting is reset. The shutoff valve 102 is provided in the gas leak detection device including the gas leak determination means 104 that resets the time count from the initial value (= 0) to a state in which counting can be newly started.
A signal for controlling the open / closed state of the shutoff valve 102
When the shut-off valve opening / closing control means 105 for controlling the opening / closing of the shut-off valve and a signal for controlling the shut-off valve 102 in the closed state are sent from the shut-off valve opening / closing control means 105, the first A shutoff valve standby shutoff control means 106 for executing the operation of closing the valve 2 after at least the time of the second detection period T2 shorter than the detection period T1 (T2 = 60 minutes in this embodiment) has elapsed. ,
When a signal for controlling the shutoff valve 102 to be closed is sent from the shutoff valve opening / closing control means 105, the second detection period T2 from the time when the signal is received over the second detection period. Of the second detection period T2
At least one pulse corresponding to the state in which the flow of the gas is not 0 is at least one pulse and the gas flow detection means 10
When it is output from 1, the time counting by the first time counting means 103 continues without resetting, while the shutoff valve standby shutoff control means 106 does not close the shutoff valve 102 and leaves it in the open state. While keeping this, the time counting is continued for the third detection period T3 (T3 = 60 minutes in the present embodiment), and at least one pulse or more is counted during the time counting of the third detection period T3. The pulse is the gas flow detection means 1
When output from 01, it is determined that a gas leak has occurred, and the shut-off valve standby shut-off control means 106 closes the shut-off valve 102 and an alarm indicating that the gas leak has occurred. Is generated by the alarm generation means 107, but no pulse is output from the gas flow detection means 101 during the time count of the second detection period T2 or the time count of the third detection period T3. If it is determined that the gas leakage has not occurred, the first time counting means 103 is determined.
And the alarm generation means for issuing a warning indicating that the gas leakage has occurred, for resetting the time count of the above and closing the shutoff valve 102 by the shutoff valve standby shutoff control means 106. 107 are provided. In addition, this alarm generation means 1
In the present embodiment, even if the gas leakage determination means 104 determines that a gas leakage has occurred, 07 is to issue an alarm to that effect. It is needless to say that the alarm generation means 107 can be used in any of the cases in which the occurrence of gas leakage is determined in this way, since all of them issue the same warning of gas leakage. Since only one alarm generating means 107 is required, it can be said that there is a great merit in simplifying the structure of the entire device.

In the present embodiment, the first time counting means 103 detects the open / closed state of the shutoff valve directly from the open / closed state of the shutoff valve 102. However, the output signal of the shutoff valve opening / closing control means 105 is also sent to the first time counting means 103, and the shutoff valve 10 is based on this signal.
It goes without saying that the open / closed state of 2 may be detected.

Further, the gas flow detecting means 10
1, the shutoff valve 102, the first time counting means 1
03, gas leakage determination means 104, shutoff valve opening / closing control means 105, shutoff valve standby shutoff control means 1
06, the alarm generation means 107, and the standby cutoff leakage determination means 108 are in the middle of the gas supply pipe 1 for conducting the gas supplied from the gas supply source from the gas supply source to the gas consuming equipment on the downstream side. In the inside of the gas meter 200 for measuring the integrated flow rate of the gas, the gas flow rate detecting means for the gas meter 200, the shutoff valve, the first time counting means, and the gas leakage determining means are also used in combination. ing.

Further, the shutoff valve opening / closing control means 105 has valve opening / closing changeover switches 3a, 3b as an instruction input interface, and corresponds to an input using the valve opening / closing changeover switches 3a, 3b. The shutoff valve 1
Shut-off valve opening / closing control means 105 for sending out a signal for controlling opening / closing of the valve 02, said valve opening / closing changeover switches 3a, 3b
Is at a position different from the main body of the gas leak detection device, that is, the main body of the gas meter 200 in which at least the shutoff valve 102 and the gas flow detection means 101 are arranged (in the present embodiment, in the living room of the user), and the operation device 300. It is disposed above and is connected to the main body of the gas meter 200, which is the main body of the gas leakage detection device, via the transmission means 400.

It goes without saying that the alarm generating means 107 may be arranged on the operating device 300 side instead of the main body of the gas meter 200. Further, the operation device 300 may be installed on the front surface of the gas meter 200 or attached thereto, but it is desirable to install the operation device 300 in the user's living room or the like in consideration of the operability of the user.

Further, in the present embodiment, since the purpose is to describe in detail the constitution and operation of the main part of the gas leakage detection device according to the present invention, the structure as a general gas meter other than that is described. As for functions and functions, that of a general gas meter may be used. Rather, it is preferable to be able to use a general gas meter as much as possible when adding a main part of the gas leakage detection device according to the present invention, and the gas leakage detection according to the present invention can be performed. The structure of the main part of the apparatus can be arranged in such a general gas meter, and at least a part of the constituent parts of the gas meter as described above can be used in combination, so that the present invention can be used. The configuration of the main part of such a gas leakage detection device also has an advantage that it can be installed extremely easily in a general gas meter.

Therefore, with respect to the configuration and the operation thereof as a general gas meter other than the configuration and the operation of the main part of the gas leakage detection device according to the present invention, that of a general gas meter may be used. In this embodiment, in order to simplify the description of the main part, detailed description and illustration of the part as the gas meter main body are omitted.

Next, the main operation of the above-described gas leakage detection apparatus according to the present invention will be described below, focusing on the operation of the standby cutoff leakage determination means 108 particularly when the gas usage is stopped. FIG. 2 is a schematic flowchart showing the main operation of the gas leakage detection device according to the present invention.

When using a normal gas, the user uses the valve opening / closing changeover switches 3a and 3b of the operating device 300 to open the shutoff valve 102 (N in s1) to continue the gas supply to consume the gas. Is continued (s2). Then, when it becomes time to stop using the gas, for example, after the operation stop time at midnight, the user depresses the valve opening / closing change-over switch 3b of the operation device 300 to switch the shutoff valve 102 to the closed state. Perform (Y of s1).

Then, based on this command input, the shutoff valve opening / closing control means 105 sends the signal S for controlling the shutoff valve 102 to the closed state to the shutoff valve standby shutoff control means 106 (s3). When the shutoff valve standby shutoff control means 106 receives the signal S, the shutoff valve standby shutoff control means 106 sets a time count t2 of T2 = 60 minutes in the present embodiment as the time of the second detection period T2 from the time of receiving the signal S. Counting starts from an initial value t2 = 0 (s4).

If no pulse is output (detected) during the time count of the second detection period T2 (Y of s5) (N of s6 to N of s5), gas leakage is caused. Since it is determined that it has not occurred, in this case, the standby shutoff leakage determination means 108 resets the time count of the first time counting means 103 (s8) and closes the shutoff valve 102. (S9), the standby shutoff is completed and the gas shutoff state is entered.

On the other hand, during the time counting of the second detection period T2 (Y of s5), at least one pulse is output (detected) corresponding to the gas flow from the gas flow detection means 101. If (detected), (s
6), the shut-off valve standby shut-off control means 106 further sets the third time count t3 to the initial value t2 = T3 = 60 minutes in this embodiment as the third detection period T3 from that time point. Counting is started from 0 and this is continued (s7).

Subsequently, when no pulse is output (detected) during the time count of the third detection period T3 (Y of s10) (N of s11 to N of s10), the standby state is achieved. The shutoff leakage determination means 108 determines that no gas leakage has occurred, resets the time count of the first time counting means 103 (s8), and closes the shutoff valve 102 (s9). ), The standby shutoff operation during the second detection period and the third detection period is completely finished, and the shutoff state at the time of gas stop is completely entered.

On the other hand, during the time counting of the third detection period T3 (Y of s10), that is, in the present embodiment, at least one pulse is output (detected) corresponding to the gas flow within T3 = 60 minutes. When a pulse is output (detected) from the gas flow detection means 101 (Y in s11), the standby cutoff leakage determination means 108 at that time.
Determines that a gas leak has occurred (s12),
A warning to that effect is issued by the alarm generation means 107 (s
Along with 13), the time count of the first time counting means 103 is reset to the initial value = 0 (s14). At this time, the shutoff valve 102 is closed (s15). In this way, the standby cutoff is completed and the cutoff state at the time of gas stop is completely entered.

As described above, even if the gas leakage is determined or left undetermined, after the standby shutoff is completed and the gas shutoff state is completely entered, the user again turns off the gas. At the start of use, the user presses the valve opening / closing changeover switch 3a of the operating device 300 to switch the shutoff valve 102 to the open state (Y in s16).

Then, based on the input of the switching command to the open state, the shutoff valve opening / closing control means 105 causes the shutoff valve 102 to operate.
The shutoff valve 1 controls the signal R that controls the valve to return to the open state.
(S17). Then, based on this signal R, the shutoff valve 102 returns the valve 2 which was in the shutoff state to the open state again (s18).

At this time, the signal R is also sent to the shutoff valve standby shutoff control means 106. However, this is a part of the transmission of the command for forcibly ending the series of standby cutoff operations in the interrupt mode when the above standby cutoff is not completed completely, that is, in the operation stage in the middle of s1 to s15. Also, with respect to the parts other than the shutoff valve standby shutoff control means 106, the shutoff valve 102 is returned to the open state, and this is detected to perform the standby shutoff operation in the interrupt mode. To force it to end.

That is, in this embodiment, s in FIG.
Each step from 16 onward to s18 is an operation in the middle of a series of operations of s1 to s15 of the above standby cutoff from the time when Y of s16, that is, the valve opening / closing changeover switch 3a of the operation device 300 is pressed by the user. This means that even if the input is made at the stage, it is executed in the interrupt mode so that it is forcibly terminated during the operation.

In the present embodiment, the third detection period T
If no pulse is detected in 3,
The case where the time count of the first time counting means 103 which has been counted and stopped until then is reset (that is, particularly when s8 is executed) has been described, but the pulse is set to 1 during the third detection period T3. Even if no pulse is detected, at least one pulse is detected during the second detection period T2. In that case, it is considered that gas leakage has occurred, and the pulse is counted until then and is temporarily stopped. First time counting means 10
The time count t1 of 3 is stored as it is without being reset, and the first time counting means 10 is started from the time when the shutoff valve is returned to the open state and the gas use is restarted.
It is also possible to continue counting the time count t1 of the first detection cycle T1 of 3 and monitor (detect) the gas leakage during that time. That is, the above s8 may be omitted.

Alternatively, it goes without saying that the pulse detection in the third detection period may not be performed, and if even one pulse is detected in the second detection period, it may be immediately determined that gas leakage has occurred. . That is, s7
It is also possible to omit s11 and to immediately proceed to s12 from Y in s6. However, when the pulse detection (s7 to s11) in the third detection period is omitted in this way, the determination accuracy is rougher than in the case where the pulse detection in the third detection period is performed as described above. It goes without saying that there is a tendency to become However, on the other hand, the time during which the gas flow detection means 101 and the like are continuously operated until the complete shift to the forced shutoff state can be completed in a shorter time than the above. There is an advantage that power consumption can be saved.

Next, the first time counting means 103 when using general gas with the shutoff valve 102 opened.
The gas leak detection operation in the first detection cycle T1 according to the above is shown as s (step) 19 in FIG. 2, but the content thereof is shown separately in FIG. That is, as shown in FIG. 3, first, when even one pulse is detected by the gas flow detection means 101 (Y of s20), the first time counting means 103.
Starts counting the time count t1 (s21).

Then, the first time counting means 103
The time count t1 is continuously counted up to the first detection cycle T1 (N of s22 to s20 to s21), during which pulses are continuously detected without interruption (Y of s20), the first detection is performed in that state. When the count-up is completed up to the cycle T1 (Y in s22), that is, when the state in which a pulse is detected for at least one pulse every 60 minutes over 30 days continues, the gas leakage determination means 104
Determines that a gas leak has occurred, and alarm generation means 1
An alarm is issued by 07 (s23). When the occurrence of gas leakage is determined in this way, the shutoff valve 1 is immediately stopped.
02 is shut off (s24), the gas leakage at that time is prevented from expanding, and the immediate safety is ensured and the time count t1 is reset (s2).
5).

On the other hand, in the above s20, when a state in which no pulse is detected in 60 minutes occurs (N in s20), it is considered that the gas flow is completely stopped. Then, it is determined that there is no gas leakage, t1 is reset (s26), and the state returns to the state of waiting for a pulse to be detected again (s20).

However, here, in the middle of any of the operation steps of s20 to s25, if the input of the valve shutoff command as shown in s1 is input by interruption, any of the above s20 to s25 is performed. It is needless to say that even during the operation of the step, each operation after s1 based on the input of the valve shutoff command input at that time is executed in the interrupt mode.

[0061]

As described above in detail, according to the present invention, when the gas flow is detected even in a small amount within a predetermined detection period, such as 30 days, the gas is continuously detected. A gas leak detection device that has a gas leak detection means for determining that a leak has occurred, and has the function of forcibly shutting off the shutoff valve and stopping the counting of the detection period when the gas is not used, or a gas leak detection device similar to that In a gas leak detection device used in a microcomputer gas meter that has a function, the problem of erroneous determination of gas leak due to the continued counting of the detection period before and after the gas is stopped is solved, and accurate and reliable gas leak Judgment can be performed, and the shutoff valve can be forcibly shut off during gas stoppage to maintain safety, and the power consumption during that period can be kept to almost zero. Capable of corresponding to the additional long-term use request of the microcomputer gas meter to achieve power consumption reduction, it is possible to provide a gas leakage detection device.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a configuration of a gas leakage detection device according to the present invention.

FIG. 2 is a schematic flowchart mainly showing a standby cutoff operation, which is a particularly main operation of the gas leakage detection device according to the present invention.

FIG. 3 shows a first time counting means 103 for first use of a general gas when the shutoff valve 102 is open.
5 is a schematic flowchart showing the operation of gas leakage detection in the detection cycle T1 of FIG.

[Explanation of symbols]

1 ... Gas supply piping 2 ... valve 3a, 3b ... Valve open / close selector switch 200 ... Gas meter (main unit) 300 ... Operation device 400 ... Transmission means 101 ... Gas flow detection means 102 ... Shut-off valve 103 ... First time counting means 104 ... Gas leakage determination means 105 ... Shutoff valve opening / closing control means 106. Shutoff valve standby shutoff control means 107 ... Alarm generating means 108 ... Leakage judging means at standby shutdown

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Megumi Iwakawa, 4-1-2 Hiranomachi, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. (56) Reference JP-A-6-307909 (JP, A) JP Sho 63-52031 (JP, A) JP 59-121300 (JP, A) JP 8-28799 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01M 3 / 00 G01F 1/00 G01F 3/22 G01M 3/26

Claims (5)

(57) [Claims] 1. A gas supply pipe that connects a gas supplied from a gas supply source to a gas consuming device on the downstream side from the gas supply source is arranged in the middle of the gas supply pipe and at least one pulse is generated corresponding to the flow of the gas. A gas flow detection means for outputting and detecting the flow of the gas, a shut-off valve arranged in the middle of the gas supply pipe to stop and conduct the flow of the gas by opening and closing the valve, and a predetermined first Is a first time counting means for continuing the time counting over the detection period of, and continues the time counting only during the period when the shutoff valve is in the open state, but during the period when the shutoff valve is in the closed state. Is counted by the first time counting means for temporarily stopping the time counting and continuing the once stopped time counting when the shutoff valve returns to the open state again, and the first time counting means. When the gas flow detection means continuously detects the gas flow without interruption over the first detection period, it is determined that gas leakage has occurred, and the first detection period When the stop of the gas flow is detected during the continuation of the time counting, the time counting is stopped, the time counting is reset, and the time counting can be restarted from the initial value. In a gas leakage detection device having a gas leakage determination means for returning, a shutoff valve opening / closing control means for sending a signal for controlling the open / closed state of the shutoff valve to control opening / closing of the shutoff valve, and the shutoff valve opening / closing control means When a signal for controlling the shutoff valve to be closed is sent, at least a time period from the time of receiving the signal to the second detection period shorter than the first detection period has elapsed. After the shutoff valve standby shutoff control means for executing the operation of closing the valve and a signal for controlling the shutoff valve to be closed are sent from the shutoff valve opening / closing control means, from the time when the signal is received, The time count of the second detection period is continued over the second detection period, and at least one pulse corresponding to a state where the gas flow is not 0 is generated during the second detection period. When output from the gas flow detection means,
While the time counting by the first time counting means continues without being reset, the time counting is further continued for a third detection period while the shutoff valve is kept open, and the third detection period is continued. When at least one pulse is output from the gas flow detection means during the time counting of the above, it is determined that gas leakage has occurred, and the shutoff valve is shut off by the shutoff valve standby shutoff control means. The alarm generation means issues an alarm indicating that the gas leakage has occurred while the switch is closed.
If no one pulse is output during the time counting of the second detection period or the time counting of the third detection period, it is determined that no gas leakage has occurred. A standby-shutdown-leakage determining means for resetting the time count of the time counting means of No. 1 and closing the shutoff valve by the shutoff valve standby shutoff control means; and an alarm generating means for issuing the alarm. Characteristic gas leak detection device. 2. The gas leakage detection device according to claim 1, wherein at least one of the gas flow detection means, the shutoff valve, the first time counting means, and the gas leakage determination means is the gas. It is used inside a gas meter that is arranged in the middle of the gas supply pipe that conducts the gas supplied from the supply source to the gas consuming equipment on the downstream side from the gas supply source and measures the integrated flow rate of the gas. A gas leakage detection device, wherein at least one of a gas flow detection means, a shutoff valve, a first time counting means, and a gas leakage determination means is used in combination. 3. The gas leakage detection device according to claim 1, wherein the shutoff valve opening / closing control unit includes a valve opening / closing changeover switch as a command input interface, and an input using the valve opening / closing changeover switch is provided. Correspondingly, a shutoff valve opening / closing control means for sending a signal for controlling the opening / closing of the shutoff valve,
The valve opening / closing changeover switch is arranged at a position different from the main body of the gas leakage detection device in which at least the shut-off valve and the gas flow detection means are arranged. A gas leakage detection device, characterized in that it is a shutoff valve opening / closing control means that is connected as a unit. 4. The gas leakage detection device according to claim 1, wherein the standby cutoff leakage determination means outputs the pulse during the time counting of the second detection period. If no one pulse is output during the time count of the third detection period, it is determined that the possibility of gas leakage cannot be ignored and the first time count means A gas leak detection device, characterized in that the time count is a leak determination means at the time of standby cutoff that is not reset. 5. The gas leakage detection device according to claim 1, wherein the standby cutoff leakage determination means outputs at least one pulse during the time count of the second detection period. If
It is determined that gas leakage has occurred, and at that time, the time count of the first time counting means is reset, and the shutoff valve is closed by the shutoff valve standby shutoff control means. A gas leakage detection device, characterized in that it is a leakage determination means during standby shutdown in which an alarm indicating that the alarm has been generated is generated by an alarm generation means.