JPH0933312A - Resetting method and device for microcomputer fluidic gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm the reset of a cutoff valve in a shout time by measuring the flow value based on the number of times and cycle of the sensor drive in response to the size of the variation of the flow values detected after the gas flow is stabilized, and measuring the presence of absence of a gas leak based on the average value of this flow value and the flow value when the variation is detected. SOLUTION: When a cutoff valve 9 is reset, a flow sensor 6 is driven by a flow sensor drive circuit 14 at interval of 1sec to stabilize the flow rate, then the flow rate is measured at the interval of about 0.5sec shorter than the drive interval (about 6sec) at the time of normal measurement. A variation judging circuit 15 obtains the variation of the flow rates, calculates 16 the number of times of measurement, the number of times of vibration, and cycle in response to the size of the variation based on the table set in advance, drives the sensor 6 at the interval of 0.5sec tens times, and measures the flow rate. A flow rate judging circuit 17 judges that a gas leak occurs and closed the cutoff valve 9 when the average value of this measured value and the measured value when the variation is detected is the reset condition value (e.g., 3l/h) or above, and it judges that no gas leak occurs and keeps the cutoff valve 9 opened when the average value is below the reset condition value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a return method in a so-called microcomputer fluidic gas meter, which has a function of automatically shutting off gas when an abnormal flow rate or an earthquake occurs in addition to a flow rate measuring function. Regarding the device.

[0002]

2. Description of the Related Art In a microcomputer fluidic gas meter, when a shutoff valve is actuated for some reason to stop gas, it is necessary to restore the shutoff valve as soon as the cause is resolved. As the resetting means, there are a method of manually operating the reset button and a method of automatically resetting the shutoff valve by an electric signal. However, in the case of the above two restoration methods, if they are unconditionally restored as they are, there is a risk that raw gas may leak from the instrument stopper if it is opened. Conventionally, in order to prevent such a danger, in the N-type microcomputer gas meter (membrane gas meter), once the shutoff valve is opened, the gas flow is monitored for 2 minutes and the metering membrane is activated within 2 minutes. Then, when a signal of one pulse is output (see FIG. 5), it is determined that there is a gas leak and the shutoff valve is shut off again. FIG. 6 is a flow chart of the confirmation work accompanying the return of the shutoff valve.

[0003]

However, the above-mentioned confirmation work has the following problems to be solved. a. Since it is necessary to wait for 2 minutes to confirm the return,
It takes time to confirm the restoration. In particular, when a large number of meters are shut off due to an earthquake or the like, if one meter waits for 2 minutes, the recovery work will be greatly delayed. b. In N type No. 7 meter, the capacity of the measuring chamber is large,
No leaks below 50 l / h can be found.

[0004]

[Means for Solving the Problems] The technical means for solving the above problems are as follows. 1. A microcomputer configured to measure the gas flow rate with a fluidic element and a flow sensor, and to automatically shut off the gas by driving the shut-off valve built into the meter when an abnormality is found in the measured flow rate. In the fluidic gas meter, when returning the shutoff valve, first open the shutoff valve and after a certain period of time until the flow rate stabilizes, drive the flow sensor several tens of times in a short cycle to measure the flow rate. While detecting the variation in the value, the number of driving and the period for the subsequent flow rate measurement are calculated from the predetermined table according to the magnitude of this variation and the flow sensor is driven again to measure the flow rate. If the average value of the flow rate is calculated by combining this measured value and the measured value when the variation is calculated, and this average value is within the reset condition value Microcomputer fluidic gas meter return method of driving again shut-off valve in the closed in other cases as it maintains the shut-off valve is opened, the.

[0005] 2. A microcomputer configured to measure the gas flow rate with a fluidic element and a flow sensor, and to automatically shut off the gas by driving the shut-off valve built into the meter when an abnormality is found in the measured flow rate. In the fluidic gas meter, when returning the shutoff valve, first open the shutoff valve and drive the flow sensor in a short cycle to measure the gas flow to check the gas flow stability and stabilize the gas flow. By the way, the flow sensor is driven again several tens of times in a short cycle to measure the flow rate, and the variation in the measured flow rate value is detected, and the number of driving for the subsequent flow rate measurement is performed according to the magnitude of this variation. And the cycle are obtained from a predetermined table, and the flow sensor is driven again to measure the flow rate. Calculate the average value of the flow rate by combining the measured values at the time of determination, if the average value is within the reset condition value, keep the shutoff valve open, otherwise, drive the shutoff valve to close again. How to reset the microcomputer fluidic gas meter.

[0006] 3. The driving cycle of the flow sensor after the variation of the gas flow rate is determined is set to 0.5 second intervals.
Alternatively, the method of resetting the microcomputer fluidic gas meter described in 2. 4. 3. The method of resetting a microcomputer fluidic gas meter according to 2 above, wherein when the flow rate of gas is measured immediately after the valve is opened and the flow rate is stabilized, the flow sensor drive cycle is set to 1 second intervals. 5. The method for returning to the microcomputer fluidic gas meter according to 1 or 2 or 3 or 4, which judges that there is a leak and closes the shutoff valve when the average value exceeds 3 l / h.

[0007] 6. Along with detecting the flow rate of gas with a fluidic element and a flow sensor, if an abnormality is found in this flow rate, in a microcomputer fluidic gas meter configured to drive the shutoff valve incorporated in the meter to shut off the gas, When opening the shut-off valve for recovery, a flow sensor drive circuit that waits for a time set in advance as the time for the flow rate to stabilize and then drives the flow sensor in a short cycle several tens of times is provided. That, provided with a variation determination circuit for determining the variation of the flow rate value measured by measuring the flow rate detected by the flow sensor, depending on the magnitude of the variation determined by the variation determination circuit thereafter The number of times of driving and the cycle for measuring the flow rate to be performed are obtained from a predetermined table, and the flow An arithmetic circuit for driving the controller is provided, a measurement value obtained by the number of measurements and a cycle set by the arithmetic circuit, and an average value of the flow rate are obtained by combining the measurement values when the variation is obtained. In the microcomputer fluidic gas meter, the flow rate determination circuit for maintaining the shut-off valve open when the average value is within the value set as the return condition value in advance and for controlling the shut-off valve closed in other cases, Return device.

[0008] 7. Along with detecting the flow rate of gas with a fluidic element and a flow sensor, if an abnormality is found in this flow rate, in a microcomputer fluidic gas meter configured to drive the shutoff valve incorporated in the meter to shut off the gas, When the shutoff valve is opened for restoration, the flow sensor is driven in a short cycle to measure the gas flow rate, and when the measured flow rate is stable, the flow sensor is driven again in a short cycle several tens of times. A drive circuit is provided, and the variation in the measured flow rate value is detected by measuring the flow rate detected by the flow sensor, and the number of times of drive for the subsequent flow rate measurement is performed according to the magnitude of this variation. And the cycle is obtained from a predetermined table, and the flow sensor is driven again by this, and the flow rate is measured. The average value of the flow rate is calculated by combining the measured values when the variations are calculated.If the average value is within the value set as the return condition value in advance, the shutoff valve is kept open, otherwise the shutoff valve is closed. A reset device for a microcomputer fluidic gas meter, which is provided with a reset confirmation circuit for controlling.

8. 8. The reset device in the microcomputer fluidic gas meter according to 6 or 7, wherein the flow sensor drive circuit sets the drive cycle of the flow sensor after the variation of the gas flow rate is determined to be 0.5 seconds. 9. 8. The reset device in the microcomputer fluidic gas meter according to 7, wherein the flow sensor drive circuit sets the drive cycle of the flow sensor when obtaining the variation immediately after the valve is opened to an interval of 1 second. 10. In the recovery confirmation circuit, the average value of the flow rate is 3 l / h
The recovery device in the microcomputer fluidic gas meter according to 6 or 7 or 8 or 9, which is configured to close the shut-off valve when it is determined that there is leakage.

[0010]

When the reset button is pressed or a reset signal is input to restore the shutoff valve, the shutoff valve opens. After a certain waiting time has passed since the shutoff valve was opened (Claim 1 or Claim 6) or the flow sensor drive circuit drives the flow sensor, for example, at 1 second intervals to measure the flow rate, and this flow rate is stable. When it is recognized that the flow sensor is driven (Claim 2 or Claim 7), the flow sensor drive circuit drives the flow sensor 15 to 20 times at intervals of 0.5 seconds to measure the gas flow rate. Output to the variation determination circuit side in the recovery confirmation circuit. The variation determination circuit obtains the variation of the measured flow rate input from the flow sensor, finds the number of driving and the period for the subsequent flow rate measurement from a predetermined table according to the magnitude of this variation, and then repeats the flow. The sensor is driven to measure the flow rate, and the flow rate determination circuit calculates the average value of the flow rate by combining the measured value and the measured value when the variation is calculated, and the average value is, for example, 3 l / h or more. In the case, the re-shutoff valve is closed, and in the case of within the range, the reopening operation is maintained as it is and the return work is completed.

[0011]

FIG. 1 shows a microcomputer fluidic gas meter embodying the present invention. In FIG. 1, 1 is a fluidic gas meter main body, 2 is a gas inlet, 3 is a metered gas outlet, 4 is a fluidic element, 5 is a nozzle, 6
Is a flow sensor incorporated in the nozzle 5 portion, 7 is a gas flow path from the gas inlet 2 to the nozzle 5, 8 is a valve seat provided in the gas flow path 7, 9 is a shutoff valve, and a shutoff signal is When input, the shut-off valve 9 operates and the valve 10 comes into close contact with the valve seat 8 to shut off gas. Reference numeral 11 denotes a reset button, and when the button 11 is pushed when manually resetting after the shutoff valve 9 is operated, the reset mechanism in the shutoff valve 9 is actuated, the valve 10 is returned to the original state, and the valve seat Open 8 to resume gas flow.

Reference numeral 12 is a measuring unit, which is shown in FIG. 2 together with the function of calculating the flow rate from the fluid vibration (pulse) generated in the fluidic element 4 and the electric signal output from the flow sensor 6. A configuration recovery confirmation circuit 13 is incorporated. In FIG. 2, 14 is a flow sensor drive circuit (flow sensor drive interval control circuit),
When the reset signal of the shutoff valve 9 is input, the flow sensor 6 is first driven at 1 second intervals to measure the flow rate until the flow rate becomes stable, and then the flow rate is measured again at 0.5 second intervals. Then, the variation determination circuit 15 determines the variation in the flow rate, and the arithmetic circuit 16 that determines the number of driving times and the driving cycle according to the magnitude of the variation determines the number of driving times for the next measurement based on a predetermined table. Then, the flow sensor 6 is driven 20 times at 0.5 second intervals. The drive interval of the flow sensor 6 during normal flow rate measurement is 6 seconds.

Reference numeral 17 denotes a flow rate judging circuit, which is an arithmetic circuit 1.
The measured flow rate value obtained by driving in 6 and the flow rate value at the time of obtaining the variation are combined to obtain an average value of the flow rate, and when the average value is 3 l / h or more, it is determined that there is gas leakage, A signal is sent to the shutoff valve drive circuit 18 to close the shutoff valve 9 and 3 l
When it is less than / h, it is determined that there is no gas leakage, and the shutoff valve 9 is kept open. The above operation is performed by the flow sensor 6
It has been confirmed that the gas flow immediately after the valve is opened is stabilized by means of the above-mentioned method. However, the unstable gas flow immediately after the valve is opened is as shown in FIG. Set the timer to the timer as the waiting time in advance,
After that, the flow sensor 6 may be driven to shift to the gas leak confirmation operation (the above 1 or 6). FIG. 3 is a flow chart of the above-mentioned return leakage confirmation work.

[0014]

As described above, according to the present invention, at the time of restoration, after the gas flow rate is stabilized, the flow sensor is driven several tens of times at intervals shorter than the normal drive interval, for example, at 0.5 second intervals. Determine the variation, drive the subsequent flow sensor based on the number of driving times and the cycle determined in advance according to the magnitude of this variation, and see if there is any leakage from this flow rate value and the average value of the flow rate values when looking at the variation. As compared with the conventional method of performing leakage confirmation over 2 minutes, the time required for recovery confirmation is about 20 to 30 seconds as a whole, so the leakage confirmation work time is large. Can be shortened. Therefore, for example, in the event of an earthquake, when the restoration work is performed on a large number of meters, the work time can be greatly shortened, and there is an effect that the restoration is accelerated by this amount. Further, according to the present invention, the leak confirmation measurement is performed after the flow rate is stabilized after the valve is opened, so that the accuracy is high. Further, in the present invention, since the flow rate is measured by the flow sensor,
It is possible to confirm leakage in the minute flow rate range. Further, according to the present invention, the variation of the flow rate is first observed, the number of times of measurement and the period after that are determined, the measurement is performed, and the average value of the entire flow rate values is obtained as the judgment value. Presence / absence can be correctly determined.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a microcomputer fluidic gas meter embodying the present invention.

FIG. 2 is an explanatory diagram of a recovery confirmation circuit.

FIG. 3 is a return confirmation flowchart.

FIG. 4 is an explanatory diagram of a gas flow immediately after opening the valve.

FIG. 5 is a recovery confirmation time chart in the membrane gas meter.

FIG. 6 is a reset confirmation flowchart in a membrane gas meter.

[Explanation of symbols]

 1 Fluidic Gas Meter Main Body 2 Gas Inlet 3 Gas Outlet 4 Fluidic Element 5 Nozzle 6 Flow Sensor 7 Gas Flow Path 8 Valve Seat 9 Shutoff Valve 10 Valve 11 Reset Button 12 Measuring Section 13 Recovery Confirmation Circuit 14 Flow Sensor Drive Circuit 15 Variation Judgment Circuit 16 Calculation circuit 17 Flow rate determination circuit 18 Shutoff valve drive circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuto Sakai 3-2-7-123 Takasago, Katsushika-ku, Tokyo (72) Inventor Shinichi Sato 543-15 Kitano-cho, Hachioji-shi, Tokyo (72) Inventor Toshihiko Ito Aichi Clock Electric Co., Ltd. 1-270, Chitose 1-chome, Atsuta-ku, Nagoya, Aichi Prefecture (72) Inventor Koichi Ueki 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. A gas flow rate is measured by a fluidic element and a flow sensor, and when an abnormality is found in the measured flow rate, a shut-off valve incorporated in the meter is driven to automatically shut off the gas. In the microcomputer fluidic gas meter configured as above, when returning the shutoff valve, first open the shutoff valve and drive the flow sensor several tens of times in a short cycle after a certain period of time until the flow rate stabilizes, and measure the flow rate. By detecting the variation of the flow rate value measured by, the number of driving and the period for the subsequent flow rate measurement are obtained from the table that is determined beforehand according to the magnitude of this variation, and the flow sensor is driven again by this. The flow rate is measured, and the average value of the flow rate is calculated by combining this measurement value and the measurement value when the variation is calculated, and this average value is the recovery condition. If the value is within the value, the shut-off valve is kept open as it is, and in other cases, the shut-off valve is closed again and the microcomputer fluidic gas meter is restored. 2. The gas flow rate is measured by a fluidic element and a flow sensor, and when an abnormality is found in the measured flow rate, a shut-off valve incorporated in the meter is driven to automatically shut off the gas. In the microcomputer fluidic gas meter configured as described above, when returning the shutoff valve, first open the shutoff valve and drive the flow sensor at a short cycle to measure the gas flow and check the gas flow stability. When the flow is stable, the flow sensor is driven again several tens of times in a short cycle to measure the flow rate, and the variation in the measured flow rate value is detected, and the subsequent flow rate measurement is performed according to the magnitude of this variation. Then, the flow sensor is driven again to measure the flow rate by obtaining the number of driving times and the cycle from a predetermined table, and the measured value, The average value of the flow rate is calculated by combining the measured values when the variation is calculated, and if this average value is within the return condition value, the shutoff valve is maintained open, otherwise the shutoff valve is closed again. How to reset the microcomputer fluidic gas meter that is driven by. 3. The driving cycle of the flow sensor after determining the variation in the gas flow rate is set to 0.5 second intervals.
Alternatively, the method of resetting the microcomputer fluidic gas meter described in 2. 4. The method of resetting a microcomputer fluidic gas meter according to claim 2, wherein when the gas flow is measured immediately after the valve is opened and the flow rate is stabilized, the drive period of the flow sensor is set to 1 second intervals. 5. The method of resetting a microcomputer fluidic gas meter according to claim 1, 2 or 3 or 4, wherein when the average value exceeds 3 l / h, it is judged that there is a leak and the shutoff valve is closed. 6. A microcomputer configured to detect the flow rate of gas with a fluidic element and a flow sensor, and to drive the shut-off valve incorporated in the meter to shut off the gas when an abnormality is found in this flow rate. In the fluidic gas meter, when the shut-off valve is opened for recovery, the flow sensor waits for the time set in advance as the time for the flow rate to stabilize, and after this time has elapsed, the flow sensor is driven several tens of times in a short cycle. A sensor drive circuit is provided, a variation determination circuit that determines the variation of the flow rate value measured by measuring the flow rate detected by the flow sensor is provided, and the magnitude of the variation determined by the variation determination circuit. The number of driving and the period for the subsequent flow rate measurement are calculated from the predetermined table according to An arithmetic circuit for driving the flow sensor again is provided, and the average value of the flow rate is obtained by combining the measured value obtained by the number of times of measurement and the period set by the arithmetic circuit and the measured value when the variation is obtained. If the average value is within the value set as the return condition value in advance, the shutoff valve is kept open, and in other cases, a flow rate judgment circuit for controlling the shutoff valve to be closed is provided. Return device for Dick gas meter. 7. A microcomputer configured to detect the flow rate of gas by a fluidic element and a flow sensor and, when an abnormality is detected in this flow rate, shut off the gas by driving a shut-off valve incorporated in the meter. In the fluidic gas meter, when the shut-off valve is opened for restoration, the flow sensor is driven in a short cycle to measure the gas flow rate, and when the measured flow rate stabilizes, the flow sensor is again set in a short cycle for several tens of cycles. A flow sensor drive circuit for driving the flow sensor is provided, and the variation in the measured flow rate value is detected by measuring the flow rate detected by the flow sensor, and the flow rate measurement is performed thereafter according to the magnitude of this variation. The number of times of driving and the period for are determined from a predetermined table and the flow sensor is driven again to measure the flow rate. The average value of the flow rate is calculated by combining the measured value of and the measured value when the variation is calculated, and when the average value is within the value set as the return condition value in advance, the shutoff valve is kept open, and other than A recovery device for a microcomputer fluidic gas meter, which is equipped with a recovery confirmation circuit that sometimes controls the shutoff valve to close. 8. The reset in the microcomputer fluidic gas meter according to claim 6, wherein the flow sensor drive circuit sets the drive cycle of the flow sensor after the variation of the flow rate of the gas is determined to be 0.5 second intervals. apparatus. 9. A flow sensor drive circuit, wherein the drive cycle of the flow sensor is 1 when the variation is obtained immediately after the valve is opened.
The resetting device in the microcomputer fluidic gas meter according to claim 7, wherein the resetting device is set at an interval of seconds. 10. The recovery confirmation circuit is configured to close the shutoff valve by determining that there is a leak when the average value of the flow rate exceeds 3 l / h.
Returning device in the described microcomputer fluidic gas meter.