JP4486150B2 - Gas shut-off device - Google Patents

Description

  The present invention relates to a gas shut-off device as a safety measure in the use of gas, and relates to a gas shut-off function equipped with an abnormality detection function for opening a valve shut-off valve that is closed when an abnormality is detected and then returning to normal after a safety check operation. It relates to the device.

  FIG. 9 is a block diagram showing a configuration of a gas cutoff device according to a conventional example. The gas shut-off device performs a gas leak test when the gas shut-off valve shuts off the gas passage, and is divided into a flow rate method and a pressure method according to the method of performing this gas leak test. The shut-off device 50 is based on a pressure method.

In FIG. 9, the gas shut-off device 50 is attached to the gas meter 51 and outputs a one-pulse flow signal when the membrane meter makes one rotation, and measures the gas pressure in the gas passage to measure the pressure signal. A gas sensor abnormal pattern detector 54 that outputs a valve closing signal by detecting abnormal conditions such as abnormal use of gas appliances or gas leakage based on the flow rate signal, and a valve closed state. A return signal input unit 56 for outputting a return signal when a return switch provided outside to open a certain gas shut-off valve 55 is pushed by a human operation, and a gas leak when the return signal is input A valve opening / closing signal for opening the gas shut-off valve 55 for 2 seconds in order to fill the pressure for inspection, and a valve opening / closing control unit 57 for outputting a pressure filling completion signal when the opening / closing operation is completed; When a signal is input, to measure the pressure P ₁ of the pressure P ₀ and the predetermined time T ₂ after at that time, it determines that the value of P ₀ -P ₁ there is no gas leak smaller than a predetermined value And a leakage determining unit 58 that outputs a valve opening signal, and a cutoff valve driving unit 59 that drives the gas cutoff valve 55 to open and close by inputting the valve closing signal, the valve opening / closing signal, and the valve opening signal. Yes.

In the above configuration, for example, when a gas appliance is used for an abnormal time or when there is a gas leak, this gas usage abnormality is detected by the gas usage abnormality pattern detection unit 54 from the flow rate signal from the flow rate sensor 52, and a valve closing signal is generated. Since it outputs to the cutoff valve drive part 59, the gas cutoff valve 55 carries out valve closing operation | movement, and closes a gas path. Similarly, when the seismic device is activated when an earthquake occurs, the gas shutoff valve 55 is closed. At this time, since the combustion of the gas appliance is stopped, when the gas is reused, it is necessary to use it after confirming safety. For this purpose, the following operation is performed. That is, when a return switch installed outside is pressed to open the gas passage, the return signal input unit 56 outputs a return signal. In response to this return signal, the valve opening / closing control unit 57 outputs a valve opening / closing signal for opening the gas cutoff valve 55 for 2 seconds and a pressure filling completion signal. When receiving a pressure filling completion signal, the leakage determination unit 58 measures the pressure P ₀ at that time, measures the pressure P ₁ after a predetermined time T ₂ (for example, 20 seconds), and P ₀ -P _When the value of ₁ is smaller than 10 mmH ₂ O (Pdet), it is determined that there is no gas leakage and a valve opening signal is output. When the value of P ₀ -P ₁ is 10 mmH ₂ O or more, there is a possibility that raw gas is emitted from the gas appliance that has been abnormally used. Is not output.

  In the processing operation in the above-described conventional configuration, the pressure is temporarily reduced even when there is no gas leakage due to the adiabatic change due to the rapid pressure change when the gas shut-off valve is opened and closed, so it is erroneously determined that there is a gas leak. There was a problem.

In FIG. 9, when the gas shut-off valve 55 opens and closes for 2 seconds while the downstream pressure from the gas meter 51 is 0 mmH ₂ O, the pressure is temporarily increased even when there is no gas leakage due to the adiabatic change accompanying the sudden pressure change. Since it decreases, it may be erroneously determined that there is a gas leak.

  FIG. 10 is a graph showing the pressure change due to the opening / closing operation of the gas shut-off valve 55. FIG. 10 (a) shows the case where there is no gas leak, and FIG. 10 (b) shows the case where there is a gas leak.

In FIG. 10A, T ₁ is 2 seconds when the gas shut-off valve 55 is opened and closed. The pressure fluctuation P due to the adiabatic change varies between 15 and 25 mmH ₂ O, but it takes approximately 20 seconds for the pressure to stabilize. However, since the pressure P ₀ before the pressure stabilizes is measured in the conventional configuration, the pressure drop due to the gas leak and the pressure drop due to the adiabatic change may be erroneously determined.

  The present invention was devised to solve the problems of the conventional configuration, and an object of the present invention is to provide a gas shut-off device that can perform accurate gas leak detection.

  The first invention of the present application detects a gas use abnormality based on a flow sensor for measuring a gas flow rate in a gas pipe, a pressure sensor for measuring a gas pressure in the gas pipe, and a flow signal from the flow sensor. And a gas use abnormality pattern detection unit that issues a command to the shutoff valve drive unit to close the gas shutoff valve connected to the gas pipe, and a return signal for opening the gas shutoff valve that is closed due to an abnormal gas use. An input unit, a valve opening / closing control unit that receives a signal from the return signal input unit, opens the gas shut-off valve for a predetermined time, and issues a command to the shut-off valve drive unit to fill a gas pressure in the gas pipe; and the valve The waiting time measuring means for setting the waiting time from the completion of the gas pressure filling when the pressure filling completion signal is output from the opening / closing control section, and the pressure sensor when the waiting time set by the waiting time measuring means has elapsed. Measurement of gas pressure drop in the pipe is started, gas leak inspection is performed based on the gas pressure drop value after the predetermined leak judgment time has elapsed, and if there is no leak, the shut-off valve drive unit opens the gas shut-off valve. When there is a leak, there is a leak determination unit that continues the closed state of the gas shut-off valve, and when there is a leak selection signal by communication from a remote place, this leak selection signal is sent to the leak determination unit An external communication unit for transmission, and when the leakage selection signal is selected with high accuracy, the leakage determination unit is set so that the leakage determination time is longer than when normal accuracy is selected. Is.

  According to the above configuration, after an abnormal pattern of gas use is detected and the gas shut-off valve is closed by the shut-off valve driving means, the gas shut-off valve is opened and closed for a short time to perform pressure filling when returning to normal. The pressure measurement when is completed is performed before and after waiting for a time for the pressure change to stabilize. Since the waiting time measuring means is provided for outputting the inspection start signal after waiting for the pressure change to stabilize, no erroneous determination is caused in the gas leak inspection accompanying the pressure change. In addition, based on the leak selection signal given from the external communication unit by communication from a remote place when conducting periodic inspection of the gas shut-off device or when inputting and controlling information from an abnormality detection sensor such as a gas alarm The accuracy of the gas leak inspection is changed by the control. Specifically, when the high accuracy is selected through the external communication unit, the gas leak inspection time of the leak determination unit is longer than when the normal accuracy is selected. Can be set and implemented.

As described above, according to the first invention of the present application, when an abnormal pattern of gas use is detected and the gas shut-off valve is closed by the shut-off valve driving means and then returned to normal, the gas shut-off valve is used. The pressure measurement when the pressure filling is completed by opening and closing for a short time is performed before and after waiting for a time for the pressure change to stabilize. Since the waiting time measuring means is provided for outputting the inspection start signal after waiting for the pressure change to stabilize, no erroneous determination is caused in the gas leak inspection accompanying the pressure change. In addition, based on the leak selection signal given from the external communication unit by communication from a remote place when conducting periodic inspection of the gas shut-off device or when inputting and controlling information from an abnormality detection sensor such as a gas alarm The accuracy of the gas leak inspection is changed by the control. Specifically, when the high accuracy is selected through the external communication unit, the gas leak inspection time of the leak determination unit is longer than when the normal accuracy is selected. Can be set and implemented.

  Hereinafter, an embodiment of the present invention will be described together with a reference example with reference to the accompanying drawings for understanding of the present invention. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention.

  FIG. 1 is a block diagram showing a configuration of a gas cutoff device 1 according to a first reference example of the present invention. The gas shut-off device 1 is configured with an abnormality detection function.

In FIG. 1, a gas shut-off device 1 is attached to a gas meter 2 and outputs a flow rate sensor 3 that outputs a flow signal of one pulse when the membrane meter makes one rotation, and measures a gas pressure in a gas pipe to measure a pressure signal. And a gas usage abnormality pattern detection unit (gas usage abnormality pattern detection means) that detects abnormality such as abnormal use of gas appliances or gas leakage based on the flow rate signal and outputs a valve closing signal. ) 5, a return signal input unit 7 for outputting a return signal when a return switch provided outside to open the gas shut-off valve 6 in the valve closed state is pressed by a human operation, and the return signal The valve opening / closing control unit 8 outputs a valve opening / closing signal for opening the gas shutoff valve 6 for 2 seconds and a pressure filling completion signal when opening / closing is completed in order to fill the pressure for gas leakage inspection And the pressure A standby timer (the waiting time measuring means) 9 for Hama completion signal outputs a test start signal leakage after waiting a predetermined time when the input when the leak test start signal is input, the pressure P ₁ at that time Measure the pressure P ₂ after 20 seconds (see FIG. 10). If the value of P ₁ -P ₂ is smaller than 5 mmH ₂ O (Pdet), it is determined that there is no gas leakage and a valve opening signal is generated. A leakage determination unit (leakage determination means) 10 for outputting, and a cutoff valve driving unit 11 for opening and closing the gas cutoff valve 6 by inputting the valve closing signal, the valve opening / closing signal and the valve opening signal are provided. .

  In the above configuration, when the gas appliance is used for an abnormal time, a gas usage abnormality is detected by the gas usage abnormality pattern detection unit 54 from the flow rate signal from the flow rate sensor 3, and a valve closing signal is output to the shut-off valve driving unit 59. Therefore, the gas shut-off valve 55 is closed to close the gas passage.

  The operation of returning from the state where the gas passage is shut off due to abnormal use of gas will be described with reference to the flowchart shown in FIG. Note that S1, S2,... Shown in the figure are step numbers indicating processing procedures and coincide with numbers appended to the text.

  Since the combustion of the gas appliance is stopped due to the gas passage blockage, the gas appliance is installed outside the gas cutoff device 1 after confirming the safety by closing the stopper and the main plug of the gas appliance in order to return the gas to a usable state. Operate the return switch. When the return switch is pressed, the return signal input unit 7 outputs a return signal and is input to the valve opening / closing control unit 8 (S1).

  In response to this return signal, the valve opening / closing control unit 8 outputs a valve opening / closing signal and a pressure filling completion signal (S2). The valve opening / closing signal is input to the shut-off valve driving unit 11, and the shut-off valve driving unit 11 performs an opening / closing operation of opening and closing the gas shut-off valve 6 for 2 seconds. By this operation, the gas passage is filled with pressure.

The pressure filling completion signal is input to the standby timer 9, and after waiting for 20 seconds, a leak inspection is performed (S3). Since the standby timer 9 outputs a leak test start signal 20 seconds after the pressure due to valve opening and closing stabilizes, the leak determination unit 10 measures the pressure P ₁ at that time based on the pressure signal from the pressure sensor 4 (S4). . When passed further 20 seconds (S5), by measuring the pressure _{P 2 (S6), P 1} -P 2 values 5mmH ₂ O (Pdet ') is smaller than, it is determined that there is no leakage (S7) Since the leakage determination unit 10 outputs a valve opening signal (S8), the shut-off valve driving unit 11 opens the gas shut-off valve 6 to restore the use of gas. When the value of P ₁ -P ₂ is 5 mmH ₂ O or more, there is a possibility that raw gas has been emitted from the gas appliance that has been abnormally used, so the gas shut-off valve 6 remains closed. No signal is output.

  In this configuration, since the leak is determined based on the pressure measured before and after waiting for 20 seconds by the standby timer 9, the adiabatic change accompanying the rapid pressure change as shown in FIG. The influence of the pressure fluctuation due to the pressure can be eliminated, and the leak inspection can be performed accurately by waiting for 20 seconds so that the pressure drop amount and the leak amount match the theoretical curve.

  It is known that the relationship between the pressure drop and the leakage amount is expressed by Expression (1).

Here, P ₀ : initial pressure, ΔP: pressure drop amount, T: time, V ₀ : pipe capacity, Pa: atmospheric pressure, Q: leakage amount.

In the above configuration, as is apparent from the theoretical formula shown in Equation (1), if the pipe capacity V is 20 L and the pressure drop ΔP for 20 seconds is 5 mmH ₂ O, the leakage amount of 1.8 L / h is erroneously determined. It can be measured without doing. Therefore, the gas leakage is detected with high accuracy and the safety in using the gas is improved.

  Next, an embodiment of the present invention will be described. FIG. 3 is a block diagram showing the configuration of the gas shut-off device according to one embodiment, and FIG. 4 is a flowchart for explaining the operation thereof. In addition, the same code | symbol is attached | subjected to the element which is common in the structure of a previous 1st reference example, and the description is abbreviate | omitted.

  In FIG. 3, the gas shut-off device 13 is provided with an external communication unit (external communication means) 14 that outputs a return signal and a leakage accuracy selection signal by communication from a remote place in addition to the configuration of the gas shut-off device 1 described above. ing. In addition, the gas use abnormality pattern detection unit 17 is configured to receive an abnormality detection signal from an external sensor such as a seismic sensor or a gas leak alarm or an inspection signal from an inspection switch. When there is an input, a valve closing signal or a leakage accuracy selection signal is output. Furthermore, when the leakage accuracy selection signal is input from the external communication unit 14, the leakage determination unit (leakage determination unit) 16 selects the leakage determination time as normal (20 seconds) or high accuracy (60 seconds). Thus, the inspection can be performed while changing the leak detection accuracy.

  The processing procedure of the operation according to the above configuration will be described with reference to the flowchart of FIG.

  Note that S1, S2,... Shown in the figure are step numbers indicating processing procedures and coincide with numbers appended to the text.

When the return signal input unit 7 or the return signal from the external communication unit 14 is input to the valve opening / closing control unit 15 (S1), the valve opening / closing control unit 15 opens the gas shut-off valve 6 for 2 seconds for pressure filling. A close valve opening / closing signal is output to the shut-off valve drive unit 11 (S2). Simultaneously with this processing operation, a pressure filling completion signal is input to the standby timer 18. After waiting timer 18 waiting 20 seconds the pressure due to the valve is stabilized (S3), the pressure P ₁ is measured by the pressure sensor 4 (S4). Here, the standby timer 18 determines the instruction of the standby time selection signal input from the leak determination unit 16 (S5), and if the selection is normal, the standby time is set to 20 seconds. if set to 60 seconds, since outputs again the leak test signal after the lapse waiting time set (S6), the pressure P ₂ is measured by the pressure sensor 4 (S7). When the value of P ₁ -P ₂ is smaller than 5 mmH ₂ O (Pdet ′), the leakage determination unit 16 determines that there is no leakage (S8), and outputs a valve opening signal to the cutoff valve driving unit 11 (S9). The shutoff valve drive unit 11 turns the gas shutoff valve 6 on when the gas use abnormal pattern detection unit 17 does not receive a valve close signal due to an abnormality detection signal from an external sensor or a check signal from a check switch or the like (S10). Open to restore gas use.

  Next, a second reference example of the present invention will be described. FIG. 5 is a block diagram showing a configuration of a gas shut-off device according to a second reference example, and FIG. 6 is a flowchart for explaining the operation thereof. In addition, the same code | symbol is attached | subjected to the element which is common in a previous structure, and the description is abbreviate | omitted.

  In FIG. 5, the gas shut-off device 20 is different from the configuration of the previous gas shut-off device 1 in the processing operation in the leakage determination unit 21. A processing procedure including a processing operation by the leakage determination unit 21 will be described with reference to a flowchart of FIG. Note that S1, S2,... Shown in the figure are step numbers indicating processing procedures and coincide with numbers appended to the text.

When a return signal is input from the return signal input unit 7 to the valve opening / closing control unit 8 (S1), the valve opening / closing control unit 8 opens a valve opening / closing signal that opens and closes the gas shut-off valve 6 for 2 seconds for pressure filling. It outputs to the cutoff valve drive part 11 (S2). Simultaneously with this processing operation, a pressure filling completion signal is input to the standby timer 9. Relay timer 9 waits 20 seconds the pressure due to the valve is stabilized (S3), since outputs a leakage inspection start signal, the pressure P ₁ is measured by the pressure sensor 4 (S4). The pressure P ₁ is determined whether 100 mm H ₂ O or more supply pressure specified (S5), only after 20 seconds if there 100 mm H ₂ O or more (S6), the pressure P ₂ is measured by the pressure sensor 4 ( S7). When the value of P ₁ -P ₂ is smaller than 5 mmH ₂ O (Pdet ′), the leakage determination unit 16 determines that there is no leakage (S8), and outputs a valve opening signal to the cutoff valve driving unit 11 (S9).

  With the above processing operation of the leakage determination unit 21 in this configuration, leakage determination can be performed in a shorter time.

  Next, a third reference example of the present invention will be described. FIG. 7 is a block diagram showing a configuration of a gas cutoff device according to a third reference example, and FIG. 8 is a flowchart for explaining the operation thereof. In addition, the same code | symbol is attached | subjected to the element which is common in a previous structure, and the description is abbreviate | omitted.

  In FIG. 7, the gas shut-off device 23 is configured by providing a flow rate monitoring unit 24 in addition to the configuration of the previous gas shut-off device 1 as shown in FIG. 7, and the overall processing operation differs accordingly. The procedure of this processing operation will be described with reference to the flowchart of FIG. Note that S1, S2,... Shown in the figure are step numbers indicating processing procedures and coincide with numbers appended to the text.

When a return signal is input from the return signal input unit 7 to the valve opening / closing control unit 25 (S1), the valve opening / closing control unit 8 sends a valve opening / closing signal that opens and closes the gas shut-off valve 6 for 2 seconds for pressure filling. It outputs to the cutoff valve drive part 11 (S2). Simultaneously with this processing operation, a pressure filling completion signal is input to the standby timer 9. Since the pressure filling completion signal is also input to the flow rate monitoring unit 24, the flow rate monitoring unit 24 takes in the flow rate signal from the flow rate sensor 3 (S3). After waiting timer 9 waiting 20 seconds the pressure due to the valve is stabilized (S4), since outputs a leakage inspection start signal, the pressure P ₁ is measured by the pressure sensor 4 (S5). After a further lapse of 20 seconds (S6), the pressure P ₂ is measured by the pressure sensor 4 (S7). The leakage judgment unit 26 has a value of P ₁ −P ₂ of 5 mmH ₂ O (Pde
If it is smaller than t ′), it is determined that there is no leakage and a corresponding signal is output (S8). Next, it is determined whether or not there is a leak-free signal (S9). If there is a leak-free signal, a valve opening output is output to open the valve (S10). If there is no leak signal, a valve closing signal is output. Then, the valve is closed (S11).

The flow rate monitoring unit 24 monitors the flow rate signal from the flow rate sensor 3 until the leak determination unit 26 measures the pressure P ₂ by the pressure sensor 4 when the pressure filling completion signal is input. A none signal is output (S9). By this process, when there is a gas leak on the upstream side even though the gas shut-off valve 6 is closed due to a failure of the gas shut-off valve 6 or the like, the accuracy of the leak judgment in a state that cannot be detected by pressure measurement is increased. Can do.

  When the leak-free signal is input to the leak determination unit 26, the leak determination unit 26 outputs a valve open signal to the shut-off valve drive unit 11 when there is no leak determination in the previous pressure test (S10). The valve drive unit 11 opens the gas shut-off valve 6 to restore the use of gas. When leakage is detected by the flow rate monitoring unit 24, no leakage signal is not output, so a valve closing signal is output and the gas shutoff valve 6 is maintained closed (S11).

It is a block diagram which shows the structure of the gas interruption | blocking apparatus which concerns on the 1st reference example of this invention. It is a flowchart which shows the procedure of the processing operation by the said structure. It is a block diagram which shows the structure of the gas cutoff device which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the processing operation by the said structure. It is a block diagram which shows the structure of the gas cutoff apparatus which concerns on the 2nd reference example of this invention. It is a flowchart which shows the procedure of the processing operation by the said structure. It is a block diagram which shows the structure of the gas cutoff apparatus which concerns on the 3rd reference example of this invention. It is a flowchart which shows the procedure of the processing operation by the said structure. It is a block diagram which shows the structure of the gas cutoff device which concerns on a prior art. It is a graph which shows the state of the pressure change for a gas leak test, (a) is a state without a gas leak, (b) is a state with a gas leak.

1, 13, 20, 23 Gas shut-off device 3 Flow rate sensor 4 Pressure sensor 5, 17, 27 Gas use abnormality pattern detection unit (gas use abnormality pattern detection means)
6 Gas shut-off valve 7 Return signal input unit 8, 15, 25 Valve open / close control unit (valve open / close control means)
9 Waiting timer (waiting time measuring means)
10, 16, 21, 26 Leakage determination unit (leakage determination means)
11 Shut-off valve drive section (shut-off valve drive means)
14 External communication unit (external communication means)
13 Pressure judgment value change part

Claims (1)

A flow sensor that measures the gas flow rate in the gas pipe, a pressure sensor that measures the gas pressure in the gas pipe, and an abnormal gas usage based on the flow signal from the flow sensor, and connected to the gas pipe A gas use abnormality pattern detection unit that issues a command to the shutoff valve drive unit to close the gas shutoff valve, a return signal input unit for opening and returning the gas shutoff valve that is in a closed state due to an abnormal gas use, and the return signal Upon receipt of a signal from the input unit, the gas shut-off valve is opened for a predetermined time, and a valve opening / closing control unit that issues a command to the shut-off valve drive unit to fill the gas pipe with gas pressure, and pressure filling is completed from the valve open / close control unit A waiting time measuring means for setting a waiting time from the completion of gas pressure filling when the signal is output, and the gas pressure in the gas pipe by the pressure sensor when the waiting time set by the waiting time measuring means has elapsed. Starts a drop measurement, and checks for gas leaks based on the gas pressure drop after a predetermined leak judgment time. If there is no leak, the shut-off valve drive opens the gas shut-off valve and returns to the normal state. A leakage determination unit that continues the closed state of the gas shut-off valve when there is a leakage, and an external communication unit that transmits the leakage selection signal to the leakage determination unit when there is a leakage selection signal by communication from a remote place; And the leak determination unit is configured to set the leak determination time to be longer than when the normal accuracy is selected when the leak selection signal is selected with high accuracy.

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