JP4860250B2 - Gas shut-off device - Google Patents

Description

  In the present invention, when the gas shut-off device opens and closes the gas passage, the abnormality determination based on the flow rate that does not assume the measurement condition is not performed.

  Conventionally, this type of gas shut-off device is configured as described in Patent Document 1.

FIG. 5 shows a conventional gas cutoff device described in Patent Document 1. In FIG. As shown in FIG. 5, the flow rate detection unit 1 that outputs a flow rate signal a corresponding to the gas flow rate that passes through the gas passage, and the flow rate b that calculates the flow rate b when the flow rate signal a of the flow rate detection unit 1 is received. When the flow rate b of the flow rate calculation unit 2 is received, the calculation unit 2, the abnormal flow rate determination unit 3 that outputs a valve closing signal c if it is abnormal as compared with a determination value held in advance, and the abnormal flow rate determination unit 3, when the valve closing signal c of 3 or the valve opening signal e of the return input unit 8 or the valve closing signal c of the sensor abnormality determination unit 6 is received, the valve driving unit 4 outputs a valve driving signal d, and the valve driving unit 4 When the valve driving signal d is received, the valve 5 that opens or closes the gas passage and the flow rate signal a of the flow rate detection unit 1 is subjected to an abnormality determination to determine whether or not it meets a predetermined abnormal condition. The sensor that outputs the valve closing signal c only when it is established. The abnormality determination unit 6, the integration unit 7 that integrates and holds the flow rate b when receiving the flow rate b of the flow rate calculation unit 2, and the return input that outputs the valve opening signal e when receiving a return input from the outside Part 8.
Japanese Patent No. 3624642

  However, in the conventional configuration, abnormal flow determination, sensor abnormality determination, and integration are performed based on the flow signal a detected by the flow detection unit 1, so that the flow type signal a When different gases (for example, when changing the amount of heat or when installing or replacing a gas shut-off device) are mixed non-uniformly, the flow rate is not as expected for the measurement conditions (if the gas layer is non-uniform, the propagation of ultrasonic waves is uniform. There is a possibility of showing different ways).

  The flow rate measurement of the ultrasonic gas shut-off device is configured to switch the transmission and reception of the sensor from the upstream side to the downstream side and from the downstream side to the upstream side, and obtain the flow velocity from the difference in the propagation time T. That is, the ultrasonic wave output from the sensor on the transmitting side is acquired as a waveform as shown in FIG. 6 on the receiving side, and the time when the third wave exceeds the third wave and zero crosses for the first time is measured as the propagation time T. Yes. For this reason, if the entire waveform is not an appropriate size, an abnormal flow velocity is calculated.

  In order to create an appropriate waveform, the gain is corrected so that the maximum peak of the waveform falls between VH and VL so that the third wave of the waveform always exceeds the V level for the first time. Therefore, when the gain correction requires unexpected fluctuations (when the gain increases or decreases cannot be followed, or when an appropriate waveform cannot be obtained due to sticking to the upper and lower limits). There is a problem that the measured flow velocity may become abnormal (for example, when the V level exceeds the V level for the first time at the second or fourth wave, or when the peak of all waveforms does not exceed the V level). Was.

The present invention solves the above-described conventional problems, and avoids a determination based on a flow rate signal that does not assume the measurement condition, so that the measurement condition may not be assumed (for example, when the heat amount is changed or gas is changed). In the shutdown / return timing including when installing and replacing the shut-off device, the abnormal flow signal that is transient (until the gas different from the gas type becomes uniform) can be bypassed for an arbitrary period of time to perform an abnormality determination process. An object of the present invention is to provide a gas shut-off device that can be avoided.

  In order to solve the conventional problem, the gas shutoff device of the present invention outputs a bypass signal for an arbitrary time when the abnormal bypass unit receives the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit, The sensor abnormality determination unit stops the abnormality determination if there is a bypass signal.

  This bypasses the transient abnormal flow signal that may occur when the gas shut-off device opens and closes the valve for an arbitrary period of time, thereby avoiding an abnormality determination process based on a flow rate that is not expected of the measurement conditions. be able to.

  The gas shut-off device of the present invention can bypass any time sensor abnormality determination, and can eliminate a transient abnormal flow signal. Therefore, it is possible to distinguish between a permanent sensor or measurement circuit that is physically damaged or malfunctioning and a sensor or measurement circuit that is based on a transient abnormal flow signal, thereby improving system reliability. be able to.

A first aspect of the present invention is a gas shut-off device provided with a valve that shuts off a gas flow in the gas passage when it is determined that the gas flow rate in the gas passage is abnormal. A flow rate detection unit that outputs a flow rate signal by providing a sensor that detects a physical quantity corresponding to the flow rate, a flow rate calculation unit that inputs a flow rate signal of the flow rate detection unit and calculates a flow rate, and a flow rate value calculated by the flow rate calculation unit in advance An abnormal flow rate determination unit that outputs a valve closing signal if it is abnormal by comparing with a determination value that is held, and a valve closing signal when the flow rate signal from the flow rate detection unit matches a predetermined abnormal condition A sensor abnormality determination unit that outputs a valve, a return input unit that outputs a valve open signal when a return input from the valve closed state to the valve open state is input from an external communication or a switch provided in the gas shut-off device, and the abnormal flow rate Judgment valve closed Or a valve driving signal for inputting a valve opening signal of the return input unit or a valve closing signal of the sensor abnormality determining unit and outputting a valve driving signal, and a gas passage is opened when the valve driving signal of the valve driving unit is received. Or a valve for closing, and an abnormal bypass unit that inputs a valve closing signal of the abnormal flow rate determination unit or a valve opening signal of the return input unit and outputs a bypass signal for a predetermined time, and the sensor abnormality determination unit includes the abnormality If there is no bypass signal from the bypass unit, an abnormality determination is performed as to whether or not the flow rate signal of the flow rate detection unit matches a predetermined abnormal condition, and a valve closing signal is output when the abnormality is established. If there is a bypass signal, the determination of the predetermined abnormal condition is stopped, and the abnormal bypass unit inputs the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit. By bypassing the determination of the predetermined time the flow detector of the flow signal as a point, it can be such that the sensor abnormality determination unit determines that no abnormal flow signal unexpected measurement conditions.

According to a second aspect of the present invention, in the gas shut-off device provided with a valve for shutting off the gas flow in the gas passage when it is determined that the gas flow rate in the gas passage is abnormal, the gas flow rate passing through the gas passage A flow rate detection unit that outputs a flow rate signal in response to the flow rate, a flow rate calculation unit that inputs a flow rate signal of the flow rate detection unit to calculate a flow rate, a flow rate value calculated by the flow rate calculation unit, and a determination value that is held in advance An abnormal flow rate determination unit that outputs a valve closing signal if abnormal, a return input unit that outputs the valve opening signal when receiving a return input from the valve closed state to the valve open state from the outside, and the abnormality A valve driving unit that inputs a valve closing signal of a flow rate determination unit or a valve opening signal of a return input unit and outputs a valve driving signal; a valve that inputs a valve driving signal of the valve driving unit and opens or closes a gas passage; , The valve closing signal of the abnormal flow rate determination unit or the An integration bypass unit that inputs a valve opening signal of the return input unit and stops outputting the flow rate value from the flow rate calculation unit for a predetermined time, and an integration that accumulates and holds the flow rate value when receiving the flow rate value from the integration bypass unit The integrated bypass unit stops the output of the flow rate value from the integrated bypass unit for a predetermined time from the input of the valve closing signal of the abnormal flow rate determining unit or the valve opening signal of the return input unit. Thereby, it is possible to prevent the integration unit from integrating the flow rate value that is not expected of the measurement conditions.

  According to a third aspect of the present invention, in the gas shut-off device provided with a valve for shutting off the gas flow in the gas passage when it is determined that the gas flow rate in the gas passage is abnormal, the gas flow rate passing through the gas passage A flow rate detection unit that outputs a flow rate signal in response to the flow rate, a flow rate calculation unit that inputs a flow rate signal of the flow rate detection unit to calculate a gas flow rate, and an abnormality compared with a judgment value that is held in advance when the flow rate value is received If so, the abnormal flow determination unit that outputs a valve close signal, the valve drive unit that outputs a valve drive signal when receiving the valve close signal of the abnormal flow determination unit or the valve open signal of the return input unit, and the valve A valve that opens and closes the gas passage by inputting a valve drive signal of the drive unit, a return input unit that outputs a valve open signal when receiving a return input from the closed state to the open state, and the abnormal flow rate determination unit Valve closing signal or return input A flow rate bypass unit that stops output of a flow rate value from the flow rate calculation unit for a predetermined time upon receipt of an open signal; and By stopping the output of the flow rate value from the flow rate bypass unit for an arbitrary time from the starting point, it is possible to prevent the abnormal flow rate determination unit from determining the flow rate outside the assumption of the measurement conditions.

A fourth invention is, in particular sensor abnormality determination unit of the first invention, when the flow rate of the flow rate calculation unit if the bypass signal from the abnormality bypass section is equal to or greater than a predetermined, the determination of the predetermined abnormal condition When a failure is established, a purge completion signal is output. When the flow rate of the flow rate calculation unit is less than a predetermined value , the determination of a predetermined abnormal condition is stopped, and the purge of the sensor abnormality determination unit is stopped. When a completion signal is received, a display unit that displays purge completion and an external communication unit that notifies the outside when the purge completion signal of the sensor abnormality determination unit is received are output from the flow rate calculation unit when the abnormality determination is not established. It is possible to display and report that the abnormal state has been reliably canceled and the gas can be used normally when the flow rate is higher than a predetermined value.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a functional block diagram of a gas cutoff device in Embodiment 1 of the present invention.

  In FIG. 1, the flow rate detection unit 11 may detect a gas flow rate based on a difference in propagation time of ultrasonic waves by attaching an ultrasonic sensor facing the gas passage (for example, an ultrasonic sensor facing the gas passage) A flow rate signal A is output in correspondence with a flow path A in which a gas flow is created and a gas flow rate is detected from vibration generated when the gas flows in the passage.

  When the flow rate calculation unit 12 receives the flow rate signal A from the flow rate detection unit 11, the flow rate calculation unit 12 calculates the flow rate B.

  When the abnormal flow rate determination unit 13 receives the flow rate B of the flow rate calculation unit 12, the determination value held in advance (for example, the maximum flow rate gas flow allowed by the gas shut-off device may be used, or a small amount of gas flow rate continues. The valve closing signal C is output if there is an abnormality as compared with the case where the allowable time is exceeded after the flow continues.

When the valve drive unit 14 receives the valve close signal C of the abnormal flow rate determination unit 13, the valve open signal E of the return input unit 16 or the valve close signal C of the sensor abnormality determination unit 18, the valve drive signal D (for example, opens the valve 15). Output a signal to drive the stopper or the stopper.

  When the valve 15 receives the valve drive signal D of the valve drive unit 14, the valve 15 opens or closes the gas passage.

  When the return input unit 16 receives a return input from the outside (for example, an input by a button, a non-contact type such as a reed switch, or the same effect can be obtained by an input by a communication message), a valve opening signal is received. E is output.

  When the abnormal bypass unit 17 receives the valve closing signal C of the abnormal flow rate determining unit 13 or the valve opening signal E of the return input unit 16, the abnormal bypass unit 17 may have an arbitrary time (for example, 10 minutes until the gas different from the gas type becomes uniform). (It may be set unconditionally for 1 hour, etc.) Outputs bypass signal F (if valve closing signal C or valve opening signal E occurs again before the arbitrary time elapses, restart the arbitrary time) Can be extended).

  If there is no bypass signal F from the abnormal bypass unit 17, the sensor abnormality determination unit 18 determines that the flow rate signal A of the flow rate detection unit 11 is a predetermined abnormal condition (for example, when there is no continuous signal from the sensor, An abnormality determination is performed as to whether or not the value matches the upper and lower limit values, and the valve closing signal C is output only when the abnormality is established. If there is a bypass signal F from the abnormal bypass unit 17, the determination of a predetermined abnormal condition is stopped.

  The operation and action of the gas shut-off device configured as described above will be described below.

First, the valve closing signal C or the valve opening signal E is generated (or an abnormality may be detected by another sensor such as an earthquake, an alarm device, a pressure drop / rise, etc. The bypass signal F is output for an arbitrary time.
If there is a bypass signal F, the determination of a predetermined abnormal condition is stopped.

  As described above, in the present embodiment, the sensor abnormality determination unit 18 generates the transient abnormal flow signal A that may be generated when the gas shut-off device from the flow detection unit 11 opens and closes the valve. It is possible to eliminate the sensor abnormality determination based on the abnormal flow rate signal A.

(Embodiment 2)
FIG. 2 shows a functional block diagram of the gas cutoff device according to Embodiment 2 of the present invention.

  In FIG. 2, the flow rate detection unit 11 outputs a flow rate signal A corresponding to the gas flow rate passing through the gas passage. When the flow rate calculation unit 12 receives the flow rate signal A from the flow rate detection unit 11, the flow rate calculation unit 12 calculates the flow rate B.

  When the abnormal flow rate determination unit 13 receives the flow rate B of the flow rate calculation unit 12, the abnormal flow rate determination unit 13 compares the determination value stored in advance and outputs a valve closing signal C if abnormal.

  When the valve drive unit 14 receives the valve close signal C of the abnormal flow rate determination unit 13 or the valve open signal E of the return input unit 16, the valve drive unit 14 outputs the valve drive signal D. When the valve 15 receives the valve drive signal D of the valve drive unit 14, the valve 15 opens or closes the gas passage.

  The return input unit 16 outputs a valve opening signal E when receiving a return input from the outside.

  When the integration bypass unit 19 receives the valve closing signal C of the abnormal flow rate determination unit 13 or the valve opening signal E of the return input unit 16, the integration bypass unit 19 may have an arbitrary time (for example, 10 minutes until the gas different from the gas type is made uniform). The gain correction value may be less than the predetermined value, and the same effect can be obtained as a period until the valve is opened after it is confirmed that there is no leakage in the gas passage after the return input) The output of the flow rate B of the flow rate calculation unit 12 is stopped (if the valve closing signal C or the valve opening signal E is generated again before an arbitrary time elapses, the arbitrary time may be restarted and extended. ).

  When the integrating unit 20 receives the flow rate B from the integrating bypass unit 19, the integrating unit 20 integrates and holds the flow rate B (for example, the stored integrated value is output to the outside by wired or wireless communication or displayed on the LCD or the like). .

  The operation and action of the gas shut-off device configured as described above will be described below.

  First, the valve closing signal C or the valve opening signal E is generated (or an abnormality may be detected by another sensor such as an earthquake, an alarm device, a pressure drop / rise, etc. The output of the flow rate B for an arbitrary time is stopped.

  As described above, in the present embodiment, the integration bypass unit 19 eliminates the transient abnormal flow rate B that may occur when the gas shutoff device from the flow rate calculation unit 12 opens and closes the valve. Therefore, it is possible to avoid integrating the transient abnormal flow rate B.

(Embodiment 3)
FIG. 3 shows a functional block diagram of the gas cutoff device according to Embodiment 3 of the present invention.

  In FIG. 3, the flow rate detector 11 outputs a flow rate signal A corresponding to the gas flow rate passing through the gas passage. When the flow rate calculation unit 12 receives the flow rate signal A from the flow rate detection unit 11, the flow rate calculation unit 12 calculates the flow rate B.

  When the flow rate bypass unit 21 receives the valve close signal C of the abnormal flow rate determination unit 13 or the valve open signal E of the return input unit 16, the flow rate bypass unit 21 may have an arbitrary time (for example, 10 minutes until the gas different from the gas type becomes uniform). The gain correction value may be less than the predetermined value, and the same effect can be obtained as a period until the valve is opened after it is confirmed that there is no leakage in the gas passage after the return input) The output of the flow rate B of the flow rate calculation unit 12 is stopped (if the valve closing signal C or the valve opening signal E is generated again before an arbitrary time elapses, the arbitrary time may be restarted and extended. ).

  When the abnormal flow rate determination unit 13 receives the flow rate B from the flow rate bypass unit 21, the abnormal flow rate determination unit 13 compares the determination value stored in advance and outputs a valve closing signal C if abnormal.

  When the valve drive unit 14 receives the valve close signal C of the abnormal flow rate determination unit 13 or the valve open signal E of the return input unit 16, the valve drive unit 14 outputs the valve drive signal D. When the valve 15 receives the valve drive signal D of the valve drive unit 14, the valve 15 opens or closes the gas passage.

  When the return input unit receives a return input from the outside, it outputs a valve opening signal E.

  The operation and action of the gas shut-off device configured as described above will be described below.

First, the valve closing signal C or the valve opening signal E is generated (or an abnormality may be detected by another sensor such as an earthquake, an alarm device, a pressure drop / rise, etc. If the switch is instructed to open and close, the output of the flow rate B at any time (for example, if the flow rate is generated after the gas passage is closed, the valve is regarded as not operating completely and the abnormal flow rate judgment function is repeated to close the plug again. At this time, if the valve is driven and closed based on an incorrect flow rate, the battery as the power source of the gas shutoff device is wasted).

  As described above, in the present embodiment, the flow rate bypass unit 21 eliminates the transient abnormal flow rate B that may occur when the gas shut-off device from the flow rate calculation unit 12 opens and closes the valve. It is possible to avoid a transient abnormal flow rate B from being determined as an abnormal flow rate.

(Embodiment 4)
FIG. 4 shows a functional block diagram of the gas cutoff device according to Embodiment 4 of the present invention. Note that the same reference numerals as those in FIG.

  In FIG. 4, if there is no bypass signal F from the abnormal bypass unit 17, the sensor abnormality determination unit 18 performs abnormality determination as to whether or not the flow rate signal A of the flow rate detection unit 11 matches a predetermined abnormal condition, and the abnormality is established. Only when the valve closing signal C is output.

  If there is a bypass signal F from the abnormal bypass unit 17, the flow rate B of the flow rate calculation unit 12 is a predetermined value or more (for example, 1000 L / h or more of the amount that the gas different from the gas type is sufficiently mixed downstream) In the case of a large flow rate), a predetermined abnormal condition is determined, and if a failure is established (that is, the flow rate is no longer a transient abnormal flow), a purge completion signal G is output (at this time, the bypass signal F May be stopped).

  In addition, by stopping the accumulation bypass of the second embodiment of the present invention by the purge completion signal G (forcibly elapses an arbitrary time), the accumulation based on the transient abnormal flow rate is eliminated, and then the accumulation is resumed. You may let them.

  Further, by stopping the flow rate bypass of the third embodiment of the present invention by the purge completion signal G (forcibly allowing an arbitrary time to elapse), the abnormal flow rate determination based on the transient abnormal flow rate is eliminated, and then an abnormality is detected. The flow rate determination may be resumed.

  When the flow rate B of the flow rate calculation unit 12 is less than a predetermined value (for example, less than 1000 L / h), the determination of a predetermined abnormal condition is stopped.

  When the display unit 22 receives the purge completion signal G from the sensor abnormality determination unit 18, the display unit 22 may display a purge completion display (for example, using an LCD. The same effect can be obtained by using an LED or a display device. Note that the display period may be a fixed time (for example, 60 seconds), or a person may operate to cancel the display).

  When the external communication unit 23 receives the purge completion signal G from the sensor abnormality determination unit 18, the external communication unit 23 may notify the outside (for example, a center that monitors the gas shutoff device using a public telephone line, Instead, the same effect can be obtained by the Internet or wireless communication).

The operation and action of the gas shut-off device configured as described above will be described below.
First, when there is a bypass signal F and the flow rate B is greater than or equal to a predetermined value, a predetermined abnormal condition is determined, and if an abnormality is not established, a purge completion signal G is output, and the display output is reported to the outside.

As described above, in the present embodiment, it becomes possible to detect that the sensor abnormality determination unit 18 has escaped from the abnormal state, so that it is safe to use gas. It is possible to display to the installation worker and report to the center monitoring the gas shutoff device.

  In the first to fourth embodiments, erroneous sensor abnormality determination (integration and abnormal flow determination) based on a transient abnormal flow signal can be eliminated. In addition, it is possible to distinguish between a permanent sensor or measurement circuit that is physically damaged or faulty and an abnormality based on a transient abnormal flow signal, improving system reliability. Can do.

  As described above, the gas shutoff device according to the present invention can bypass the sensor abnormality determination for arbitrary time determination, and can eliminate a transient abnormal flow signal. Therefore, it is possible to distinguish between a sensor or measurement circuit that is physically damaged or malfunctioning and a sensor or measurement circuit that is based on a transient abnormal flow signal, and the reliability of the system can be improved. If water is replaced with water, it can be applied to uses such as water meters.

Functional block diagram of the gas cutoff device in Embodiment 1 of the present invention Functional block diagram of the gas cutoff device in Embodiment 2 of the present invention Functional block diagram of the gas cutoff device in Embodiment 3 of the present invention Functional block diagram of the gas cutoff device in Embodiment 4 of the present invention Functional block diagram of a conventional gas shut-off device Characteristics of received waveform

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Flow detection part 12 Flow calculation part 13 Abnormal flow determination part 14 Valve drive part 15 Valve 16 Return input part 17 Abnormal bypass part 18 Sensor abnormality determination part 19 Integration bypass part 20 Accumulation part 21 Flow bypass part 22 Display part 23 External communication part

Claims (4)

In a gas shut-off device provided with a valve that shuts off the flow of gas in the gas passage when it is determined that the flow rate of gas passing through the gas passage is abnormal, a physical quantity corresponding to the flow rate of gas passing through the gas passage is detected. A flow rate detection unit that outputs a flow rate signal, a flow rate calculation unit that inputs the flow rate signal of the flow rate detection unit to calculate a flow rate, and a determination that the flow rate value calculated by the flow rate calculation unit is held in advance An abnormal flow determination unit that outputs a valve closing signal if an abnormality is detected by comparing the value, and a sensor abnormality that outputs a valve closing signal when the flow signal from the flow detection unit matches a predetermined abnormal condition A determination unit, a return input unit that outputs a valve opening signal when receiving a return input from the closed state to the open state, a valve closing signal of the abnormal flow rate determining unit, a valve opening signal of the return input unit, or the sensor abnormality Judgment A valve driving unit that inputs a valve closing signal and outputs a valve driving signal; a valve that opens or closes the gas passage when receiving the valve driving signal of the valve driving unit; and a valve closing signal of the abnormal flow determination unit Or an abnormal bypass unit that inputs a valve opening signal of the return input unit and outputs a bypass signal for a predetermined time, and if the sensor abnormality determination unit has no bypass signal from the abnormal bypass unit, the flow rate of the flow rate detection unit Determines whether the signal meets a predetermined abnormal condition, outputs a valve closing signal when an abnormality is established, and stops the determination of the predetermined abnormal condition if there is a bypass signal from the abnormal bypass unit The abnormal bypass unit bypasses the determination of the flow rate signal of the flow rate detection unit for a predetermined time from the input of the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit. Gas cutoff apparatus characterized by. In a gas shut-off device provided with a valve that shuts off the flow of gas in the gas passage when it is determined that the flow rate of gas passing through the gas passage is abnormal, a flow rate signal corresponding to the flow rate of gas passing through the gas passage Compare the flow rate value calculated by the flow rate calculation unit with the judgment value stored in advance. If there is an abnormal flow determination unit that outputs a valve closing signal, a return input unit that outputs a valve opening signal when a return input from the closed state to the open state is received, and a valve closing signal or return input of the abnormal flow determination unit A valve driving unit that inputs a valve opening signal and outputs a valve driving signal; a valve that inputs a valve driving signal of the valve driving unit to open or close a gas passage; and a valve closing signal of the abnormal flow rate determination unit Or input the valve open signal of the return input section The integration bypass unit includes: an integration bypass unit that stops outputting the flow rate value from the flow rate calculation unit for a predetermined time; and an integration unit that integrates and holds the flow rate value when the flow rate value is received from the integration bypass unit. A gas shutoff device characterized in that the unit stops the output of the flow rate value from the integration bypass unit for a predetermined time from the input of the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit. In a gas shut-off device provided with a valve that shuts off the flow of gas in the gas passage when it is determined that the flow rate of gas passing through the gas passage is abnormal, a flow rate signal corresponding to the flow rate of gas passing through the gas passage A flow rate detection unit that outputs a flow rate signal from the flow rate detection unit and calculates a gas flow rate. The abnormal flow rate determination unit that outputs the valve, the valve drive signal that outputs the valve drive signal when the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit is received, and the valve drive signal of the valve drive unit Is input to open or close the gas passage, a return input unit that outputs a valve open signal when receiving a return input from the closed state to the open state, and a valve close signal or return of the abnormal flow rate determination unit In response to the valve opening signal of the input section Then, a flow rate bypass unit that stops outputting the flow rate value from the flow rate calculation unit for a predetermined time, and the flow rate bypass unit starts from the valve close signal of the abnormal flow rate determination unit or the valve open signal of the return input unit A gas shut-off device, wherein output of a flow rate value from the flow rate bypass unit is stopped for an arbitrary time. If there is a bypass signal from the abnormal bypass unit, if the flow rate value of the flow rate calculation unit is equal to or greater than a predetermined value , the sensor abnormality determination unit performs a determination of a predetermined abnormal condition, and if a failure is not established, a purge completion signal is output. When the output flow rate value of the flow rate calculation unit is less than a predetermined value , the determination of a predetermined abnormal condition is stopped, and when the purge completion signal of the sensor abnormality determination unit is received, a display unit for displaying a purge completion; An external communication unit that reports to the outside when a purge completion signal from the sensor abnormality determination unit is received, and an abnormal state is detected when the flow rate value from the flow rate calculation unit is greater than or equal to a predetermined value when abnormality determination is not established. 2. The gas shut-off device according to claim 1, wherein the gas shut-off device displays and reports that the gas is surely released and the gas can be used normally.

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