JP2005265529A - Gas shut-off device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas shut-off device for performing anomaly monitoring while distinguishing between an instrument and a leakage based on a change in a flow rate. <P>SOLUTION: A flow velocity is detected by a flow velocity detection means 14 and converted into flow rate by a flow rate computation means 20. When a change in the flow rate is detected from a flow rate value of the computation means 20, a change with time in the flow rate value is stored in a flow rate storage means 21. A comparison/determination means 23 compares a flow rate pattern of the instrument previously stored in a flow rate pattern storage means 22 with the flow rate value of the flow rate storage means in order to determine whether it is the instrument or not. When it is determined not to be the instrument but to be a leakage, a shut-off means 26 outputs a shut-off signal at once to stop gas supply. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas cutoff device that detects the flow rate of various media such as city gas and LP gas flowing in a flow path using ultrasonic waves and monitors whether the gas usage state is safe based on the change in gas flow rate.

  Conventionally, this type of gas cutoff device has a configuration as shown in FIG. 3 (see, for example, Patent Document 1).

  FIG. 3 shows a block diagram of a conventional gas shut-off device. In FIG. 3, 1 is a flow path, 2 is an upstream vibrator, and is installed on the upstream side of the flow path 1 for transmitting and receiving ultrasonic waves. Reference numeral 3 denotes an upstream vibrator that transmits and receives ultrasonic waves and is attached to the downstream side of the flow channel 1 so as to face the upstream vibrator 2. Reference numeral 4 denotes a transmission circuit that transmits an ultrasonic signal to the upstream vibrator 2, and reference numeral 5 denotes an amplification circuit that amplifies the signal received by the downstream vibrator 3. A comparison circuit 6 compares the amplified signal with a reference signal. 7 is a time measuring means, which measures the time from the transmission of the ultrasonic wave to the reception by a timer counter. Reference numeral 8 denotes a measurement circuit including the transmission circuit 4 to the time measuring means 7. A flow rate calculating means 9 obtains a flow rate value in consideration of the size of the pipe line and the flow state according to the ultrasonic propagation time by the time measuring means 7. Reference numeral 10 denotes a cycle variable means for changing the measurement cycle according to the value of the flow rate calculation means 9. Reference numeral 11 denotes a measurement start means that adjusts the signal transmission timing to the transmission circuit in accordance with the value of the period variable means 10. Reference numeral 12 denotes measurement end means for detecting the end of calculation of the flow rate calculation means 9. Reference numeral 13 denotes voltage control means for lowering the voltage of the measurement circuit 8 in synchronization with the measurement end means 12 and returning the voltage of the measurement circuit 8 in synchronization with the start of measurement by the measurement start means 11.

Next, the operation of the configuration of the conventional example will be described. In the flow path 1 through which the medium gas such as city gas or LP gas flows, a burst signal is transmitted from the transmission circuit 4 by the measurement start means 11, and the ultrasonic signal transmitted from the upstream vibrator 2 flows in the flow path 1. , And is received by the downstream vibrator 3 and further processed by the amplifier circuit 5 and the comparison circuit 6, and the time from transmission to reception is measured by the time measuring means 7. When the flow rate is large, it is necessary to reduce the error by increasing the time sampling, and when the flow rate is low or when the flow rate is zero, there is almost no error even if the measurement sampling is delayed. Therefore, the measurement interval is changed according to the value of the flow rate calculation means 9. The time interval variable means 10 with a small value of the flow rate calculation means 9 increases the measurement time interval, and as the value of the flow rate calculation means 9 increases, the measurement time interval is reduced. Further, the voltage of the measuring circuit 8 is reduced between the measurements. When the flow rate measurement means 9 finishes the flow rate measurement, a signal is sent to the measurement end means 12 and the voltage control means 13 lowers the voltage or makes it zero. The voltage starter 11 restores the voltage of the measuring circuit 8 to the original state by the voltage controller 13 before starting the measurement.
Japanese Patent Laid-Open No. 9-21667

  However, the conventional configuration has the following problems. The flow rate in the flow path 1 is measured by the upstream vibrator 2 and the downstream vibrator 3, but troubles such as piping cracking for some reason or disconnection of the hose connected to the instrument occur on the downstream side. If the flow rate is the same as that of a device, it is difficult to determine whether it is leaking or the device is used, and the time limit is set according to the flow rate considered to be a normal device, and the usage time is monitored. It is anticipated that the gas will fill the room under the floor or in the living room and the worst explosion accident or fire will occur. However, there is no disclosure of a method for judging leakage and device identification in such a case.

  The present invention solves the above problems, detects a change in flow rate unique to the appliance used, identifies the use of a gas appliance or a leak that has occurred for some reason, and accurately discriminates between the appliance and the leak. The object of the present invention is to provide a gas shut-off device that immediately stops the gas supply at the time of determination.

  In order to solve the above-described conventional problems, the gas shutoff device of the present invention detects the flow rate in the medium by the flow rate detection unit, converts the flow rate to the flow rate by the flow rate calculation unit, and detects the flow rate change from the flow rate value of the flow rate calculation unit. The storage means stores the change in the flow rate over time, the flow rate pattern of the instrument previously stored in the flow rate pattern storage means and the flow rate value of the flow rate storage means are compared by the comparison determination means, and it is determined whether or not it is an instrument. Rather than a shutoff means for outputting a shutoff signal immediately upon determination of leakage and stopping gas supply.

  As a result, even if the hose connected to the instrument comes off for some reason, or the hose is gnawed by a mouse, etc. and gas leaks, the gas supply can be identified and the gas supply can be stopped immediately. The effect is greatly improved.

  According to the gas shut-off device of the present invention, low-flow appliances such as gas tables and gas fan heaters and large-flow appliances such as GHP and water heaters possessed by gas consumers have a flow pattern unique to the appliance. , Store the flow rate change pattern peculiar to the instrument in the flow pattern storage means in advance, convert it to the flow rate value by the flow rate calculation means, compare the flow rate change pattern with the flow rate memory value stored in time series, and leak the instrument If there is a discrepancy, it is determined that the device is not an appliance, that is, if it is determined to be a leak, the gas supply is immediately stopped by the shut-off means. Thus, there is an effect that the safety and reliability can be greatly improved by accurately and accurately discriminating between the use of the appliance and the leakage without causing a trouble such as an accident.

  According to a first aspect of the present invention, flow rate detection means for measuring a signal propagation time in a medium and detecting a flow rate, flow rate calculation means for converting the flow rate from the flow rate detected by the flow rate detection means, and flow rate change by the flow rate calculation means. A flow rate storage means for storing a change in flow rate value upon detection, a flow rate pattern storage means for storing an instrument flow rate change compared with a flow rate change stored in the flow rate storage means, a flow rate storage means and the flow rate pattern storage means. Comparison determination means for comparing and specifying the appliance, average flow calculation means for obtaining an average flow rate from the stored flow rate of the flow rate storage means when the appliance is specified by the comparison determination means, and whether or not the flow rate value of the average flow calculation means is abnormal And an interruption determining means for stopping the medium supply at the time of determination as abnormal by the abnormality determining means.

  Gas appliances such as gas tables, gas fan heaters, gas heat pump air conditioners (GHP) and water heaters connected to the downstream side of the gas shut-off device are each unique when the flow rate change from the start of use of the appliance is obtained from the flow rate detection means. The flow rate change pattern is stored in advance in the flow rate pattern storage means, and when the flow rate is detected by the flow velocity detection means, the flow rate change is stored in time series, and the prestored instrument flow rate pattern is compared with the flow rate change pattern. If they match, the device is determined to be an appliance, the average flow rate is calculated by the average flow rate calculation means, and based on the obtained flow rate, the abnormal determination means is used to monitor whether the flow rate is abnormal or has not been used for a long time. When it is determined that the change pattern does not match, it is determined that the device is not an appliance, that is, it is determined that there is an abnormality such as leakage, and the gas supply is stopped immediately after driving is output to the shut-off means. It is possible to distinguish between the use of the instrument and the leak accurately and accurately without the problem that the instrument leaks for a long time and a gas leak occurs for a long time, leading to an accident in the worst explosion or fire, etc., improving safety and reliability To do.

  According to a second aspect of the present invention, flow rate detection means for measuring a signal propagation time in a medium and detecting a flow rate, flow rate calculation means for converting the flow rate from the flow rate detected by the flow rate detection means, and a driving cycle of the flow rate detection means are set. Cycle setting means for variably setting, flow rate storage means for storing a change in flow rate value when a flow rate change is detected by the flow rate calculation means, and a flow rate pattern for storing a change in instrument flow rate to be compared with the flow rate change stored in the flow rate storage means A storage unit, a comparison determination unit that compares the flow rate storage unit and the flow rate pattern storage unit to specify an appliance, and an average flow rate calculation that calculates an average flow rate from the stored flow rate of the flow rate storage unit when the appliance is specified by the comparison determination unit Means, an abnormality determining means for determining whether or not the flow rate value of the average flow rate calculating means is abnormal, and a blocking means for stopping the medium supply at the time of determination as abnormal by the abnormality determining means That.

  Gas appliances such as gas tables, gas fan heaters, gas heat pump air conditioners (GHP), and water heaters connected to the downstream side of the gas shut-off device are each unique when the flow rate change from the start of appliance use is determined by the flow rate detection means. The flow rate change pattern is stored in advance in the flow rate pattern storage unit, the flow rate is detected by the flow rate detection unit, and the cycle setting unit sets the flow rate detection cycle to a short cycle based on the flow rate value from the flow rate calculation unit. The flow rate change is detected in series, the flow rate pattern is memorized, the instrument flow rate pattern stored in advance is compared with the flow rate change pattern, and if they match, the device is determined to be an appliance and the average flow rate calculation means is used to determine the average flow rate. Based on the measured flow rate, the abnormality judgment means monitors whether the flow rate is abnormal or has not been used for a long time. In other words, it is determined that there is an abnormality such as leakage, and the drive output is immediately output to the shut-off means to stop the gas supply. Therefore, the leakage is judged for the instrument and gas leakage occurs for a long time, causing an accident such as a worst explosion or fire. In the stable flow rate range, the flow rate measurement period can be increased and the current consumption can be reduced. It can be reduced, and when using the instrument and leakage can be identified accurately and accurately, safety and reliability are improved.

  The third invention is a program for causing a computer to function as all or part of the means of the gas cutoff device of the first or second invention, and can be easily realized using a microcomputer.

  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 gas shut-off device according to a first embodiment of the present invention. Reference numeral 14 denotes a flow velocity detecting means, which is an upstream vibrator 2 and a downstream vibrator 3 that are installed opposite to a flow path 1 of a gas medium such as LP. An ultrasonic signal is transmitted from one to the other between them, and the flow velocity of the gas used is detected from the propagation time. An example of the flow velocity detection means 14 is as follows. That is, the flow velocity detection unit 14 includes a switching unit 15, a transmission unit 16, a reception unit 17, a repetition unit 18, and a propagation time measurement unit 19. The transmission means 16 and the reception means 17 are connected to the switching means 15. The switching means 15 first connects the transmission means 16 to the upstream vibrator 2, the reception means 17 to the downstream vibrator 3, and then the transmission means 16. The connection destinations of the transmission means 16 and the reception means 17 are alternately switched such that the transmission means 16 is connected to the downstream vibrator 3 and the reception means 17 is connected to the upstream vibration element 2.

  When the switching means 15 connects the receiving means 17 to the upstream vibrator 2 and the transmitting means 16 to the downstream vibrator 3, the repeating means 18 transmits the ultrasonic signal transmitted from the transmitting means 16 to the upstream vibration. The signal is received by the receiving means 17 from the downstream vibrator 3 through the flow path 1 from the child 2, but the transmission from the ultrasonic signal to the reception is repeated, and the signal propagation time is measured by the propagation time measuring means 19. Repeat the operation. The propagation time measuring means 19 measures and accumulates the time from transmission to reception of the ultrasonic signal.

  Next, the receiving means 17 is connected to the downstream vibrator 3 and the transmitting means 16 is connected to the upstream vibrator 2 by the switching means 15, and the above operation is repeated. The propagation time measuring means 19 obtains a propagation time difference from the propagation time first received and obtained and the signal propagation time measured after being switched by the switching means 15 next.

  Reference numeral 20 denotes a flow rate calculation means for obtaining a flow velocity from the obtained propagation time and further converting it to a flow rate value. A flow rate storage means 21 stores the flow rate value obtained by the flow rate calculation means 20 in a time-series manner for a predetermined time. 22 is a flow rate pattern storage means, and starts using the appliance for each appliance, such as a large flow appliance such as a water heater, a gas dryer, a heating appliance such as a No. 5 instantaneous water heater and a fan heater, and a cooking appliance such as a gas table. And a plurality of flow rate change patterns for a predetermined time from the start of use of the instrument.

  Reference numeral 23 denotes a comparison / determination unit that compares and collates the flow rate change pattern stored in the flow rate storage unit 21 with the flow rate pattern stored in advance in the flow rate change storage unit 22 to determine whether the change tendency of the flow rate change pattern is the same. If they match, it is determined as an instrument, and if they do not match, it is determined that there is some abnormality, for example, an abnormality such as gas leakage. Reference numeral 24 denotes an average flow rate calculation means, which obtains an average flow rate as a representative flow rate as an instrument from the flow rate pattern stored in the flow rate storage means 21.

  25 is an abnormality determination means for dividing abnormal flow values such as hose disconnection and flow rate ranges that can be used by the gas shut-off device, and having usage time set values corresponding to each flow rate range, and distinguishing between normal usage times of gas appliances The determination time or the like is held, and when the comparison / determination means 23 determines that the appliance is in one of the consumption categories, the abnormality determination when using the set gas appliance is determined from the flow rate value obtained by the average flow rate calculation means 24. Compare with the value to determine whether it is in an abnormal usage state.

  For example, when a connection hose to an appliance such as a stove is accidentally disconnected, an abnormal flow rate flows, but the abnormality determination means 25 compares the obtained flow rate value with the abnormality determination value to determine whether or not there is an abnormality. Alternatively, a usage time cut-off table that defines a time limit for use time corresponding to the case where the appliance such as a stove is used much longer than the normal use time is stored, and the abnormality determination means 25 is an average flow rate calculation means. The flow value obtained at 24 is monitored.

  Reference numeral 26 denotes a shut-off means, which shuts off the gas flow path 1 when a comparison / determination means 23 determines that it is not an instrument or when the abnormality determination means 25 determines that an abnormality has occurred. Reference numeral 27 denotes an informing means. When the gas judging state is judged to be abnormal by the comparison judging means 23 and the abnormality judging means 25, and the shutting means 26 is driven, the shutting state and shutoff content are displayed on the liquid crystal display element of the notifying means and the like. Report to the center (not shown) that is monitoring the safety of the gas via a telephone line.

  Next, the operation of the above configuration will be described. Usually, the LPG container is connected to a pressure regulator by a high-pressure hose, and a gas shut-off device is installed downstream thereof. The flow path 1 of the gas shut-off device is a part of a long pipe. Among these, the upstream vibrator 2 and the downstream vibrator 3 are installed obliquely to measure the flow rate by propagation of ultrasonic waves. A gas consuming appliance, for example, a gas heat pump air conditioner (GHP), a heater such as a fan heater or a stove, a water heater for supplying hot water to a bath or kitchen, and a cooking appliance such as a gas table are connected downstream of the gas shut-off device.

  Here, an example of the operation of the flow velocity detection means 14 will be described. In the flow path (gas pipe) 1, an ultrasonic signal is transmitted and received between the upstream transducer 2 and the downstream transducer 3 installed obliquely. The transmission means 16 is connected to the upstream vibrator 2 by the switching means 15, while the downstream vibrator 3 is connected to the reception means 17, and the signal transmitted from the transmission means 16 is transmitted from the upstream vibrator 2 to the downstream vibrator. 3 is received. A single-around system in which this operation is performed the number of times set by the repeating means 18 is configured. The propagation time until the reception means 17 receives the ultrasonic signal emitted from the transmission means 16 is accumulated, and the propagation time measurement means 19 obtains the time.

  Next, the switching means 15 connects the transmitting means 16 to the downstream vibrator 3 and connects the receiving means 17 to the upstream vibrator 2. An ultrasonic signal is output from the transmitting means 16 and received by the receiving means 17 connected to the upstream vibrator 2 via the flow path 1 via the downstream vibrator 3. As described above, the number of times set by the repeating means 18 is performed. The propagation time until the reception means 17 receives the ultrasonic signal emitted from the transmission means 16 is accumulated by the propagation time measurement means 19, and further the propagation time when the ultrasonic signal is emitted from the upstream to the downstream, and the downstream The difference in propagation time is obtained from the propagation time when fired upstream from. The propagation time obtained by the propagation time measuring means 19 in the flow rate computing means 20 is converted into a flow velocity value V and then converted into a flow value Q. In FIG. 1, A indicates the direction in which the gas medium flows.

  Next, the flow rate value obtained by the flow rate calculation means 20 is stored in the flow rate storage means 21 in a time-series manner. The flow rate pattern storage means 22 stores in advance a flow rate change pattern from the start of use of a typical instrument until the flow rate is stabilized.

  For example, the flow rate change pattern at the start of use of the instrument is roughly classified into gas consumption ranges of less than 5000 kcal / h, 5000 to 15000 kcal / h, and 15000 kcal / h or more. For each consumption range, that is, for each flow rate range, the sequence for each time, such as the start of use of the appliance, ignition, and the change in gas amount after detection of ignition, is roughly determined. I remember it. When the comparison determination unit 23 stores a flow rate value in a time series for a predetermined time in the flow rate storage unit 21, the comparison determination unit 23 compares and collates data in the flow rate pattern storage unit 22. The peak flow rate in the flow rate storage unit 21 is normalized and converted into the same scale as the peak flow rate in the flow rate pattern storage unit 22, and pattern matching is performed to check whether the time-series flow rate change pattern is within a standard deviation of a predetermined value. When the flow rate pattern and the detected flow rate change data are within a predetermined deviation, it is determined that the flow rate pattern and the detected flow rate match the device, and are output to the abnormality determination means 25 as a device signal. In parallel, the average flow rate calculation means 24 performs an averaging process from the time-series flow rate signals stored in the flow rate storage means 21 to obtain an average flow rate as a representative flow rate value.

  Further, when the flow rate pattern does not match with the various flow rate patterns in the entire flow rate range, when the standard deviation is larger than the predetermined value and deviates, it is determined that the device is not an instrument and an abnormality signal is output to the abnormality determination means 25. There are accident cases where the rubber hose is gnawed by a mouse or the like, causing gas leakage, but the flow rate change pattern at the time of gas detection in this case does not apply to any change in the flow rate of the instrument and can be detected immediately, and an abnormal signal is generated. The comparison determination means 23 outputs the result to the abnormality determination means 25.

  Next, from the appliance signal input from the comparison determination means 23 and the flow rate obtained from the average flow rate calculation means 24, the abnormality determination means 25 determines whether the appliance is in an abnormal use state. The abnormality determination means 25 divides the determination flow rate between the maximum flow rate usable in the gas shut-off device and the abnormal large flow rate due to hose disconnection, etc., and the flow rate range usable in the gas shut-off device to correspond to each flow rate range It has a usage time setting value. The abnormality determination unit 25 compares the flow rate calculated by the flow rate calculation unit 20 with the set abnormality determination flow rate to determine whether or not the flow rate has been exceeded. Compare with the value to determine whether it is in an abnormal long-time use state.

  For example, a use time cut-off table that defines a time limit for use time corresponding to a case where an appliance such as a stove is used much longer than the maximum use time for normal use is stored in the abnormality determination means 25. Monitors instrument flow. When the abnormality determining means 25 determines that an abnormality has occurred, a cutoff signal is output to the cutoff means 26 to shut off the gas flow path 1. On the other hand, when an abnormal signal such as leakage is input from the comparison / determination unit 23, the abnormality determination unit 25 immediately determines that the gas use state is abnormal, and drives the blocking unit 26 to stop the gas supply. When shut off, the shut-off state and the content of the shut-off are displayed on the liquid crystal display element of the informing means 27, and at the same time, a telephone line or the like is notified to the center that is monitoring the safety of the gas.

  When a flow rate change is detected by the flow rate detection means 14 during flow rate measurement in the flow path 1 where the gas shut-off device is installed in this way, the flow rate value obtained by the flow rate calculation means 20 is stored in the flow rate storage means 21 in time series. Compared with the instrument flow rate change pattern stored in the flow rate pattern storage means 22 in advance, it is possible to accurately determine whether the instrument flow rate or an abnormal flow rate such as leakage, etc. Even though a leak with the same flow rate as a stove or the like has occurred for some reason, it is regarded as an instrument and monitored for a long time. As a result, the room is filled with gas and leaks immediately without causing the worst abnormal state such as a gas explosion or fire. Since it can be identified and shut off, it is possible to accurately monitor the appliance and leakage, and to grasp the state of use of the gas, thereby improving safety and reliability.

(Embodiment 2)
FIG. 2 shows a gas cutoff device according to a second embodiment of the present invention. 2, components having the same functions as those in FIGS. 1 and 3 are denoted by the same reference numerals and description thereof is omitted.

  The difference from the first embodiment of the present invention is that the cycle variable means 28 variably sets the driving cycle of the flow velocity detection means 14. Here, the cycle variable means 28 shortens the measurement cycle when determining that there is a flow rate based on the flow rate value from the flow rate calculation means 20, that is, when detecting the instrument flow rate, and changes the measurement cycle to a longer measurement cycle when the flow rate is stable for a predetermined time. .

  Next, the operation of the above configuration will be described. Usually, the LPG container is connected to a pressure regulator by a high-pressure hose, and a gas shut-off device is installed downstream thereof. The flow path 1 of the gas shut-off device is a part of a long pipe. Among these, the upstream vibrator 2 and the downstream vibrator 3 are installed obliquely to measure the flow rate by propagation of ultrasonic waves. A gas consuming appliance, for example, a heating device such as a gas heat pump air conditioner (GHP), a fan heater, or a stove, a water heater that supplies hot water to a bath or kitchen, and a cooking appliance such as a gas table are connected to the downstream side of the gas shut-off device.

  Here, an example of the operation of the flow velocity detection means 14 will be described. In the flow path (gas pipe) 1, an ultrasonic signal is transmitted and received between the upstream transducer 2 and the downstream transducer 3 installed obliquely. The transmission means 16 is connected to the upstream vibrator 2 by the switching means 15, while the downstream vibrator 3 is connected to the reception means 17, and the signal transmitted from the transmission means 16 is transmitted from the upstream vibrator 2 to the downstream vibrator. 3 is received. A single-around system in which this operation is performed the number of times set by the repeating means 18 is configured. The propagation time until the reception means 17 receives the ultrasonic signal emitted from the transmission means 16 is accumulated, and the propagation time measurement means 19 obtains the time.

  Next, the switching means 15 connects the transmitting means 16 to the downstream vibrator 3 and connects the receiving means 17 to the upstream vibrator 2. An ultrasonic signal is output from the transmitting means 16 and received by the receiving means 17 connected to the upstream vibrator 2 via the flow path 1 via the downstream vibrator 3. As described above, the number of times set by the repeating means 18 is performed. The propagation time until the reception means 17 receives the ultrasonic signal emitted from the transmission means 16 is accumulated by the propagation time measurement means 19, and further the propagation time when the ultrasonic signal is emitted from the upstream to the downstream, and the downstream The difference in propagation time is obtained from the propagation time when fired upstream from. The propagation time obtained by the propagation time measuring means 19 in the flow rate computing means 20 is converted into a flow velocity value V and then converted into a flow value Q. In FIG. 2, A indicates the direction in which the gas medium flows.

  When the flow rate value obtained by the flow rate calculation means 20 is input to the cycle setting means 28, it is determined whether or not it is outside the predetermined flow rate range. That is, it is determined whether the flow rate is not near zero. If the flow rate is out of the predetermined flow range, there is a possibility of the instrument flow rate, and the cycle setting unit 28 sets the time to a short flow rate measurement cycle and starts the flow rate measurement of the flow rate detection unit 14 at the short cycle.

  When the flow rate is detected at the next short measurement cycle, the flow rate calculated is converted into a flow rate by the flow rate calculation means 20 and the flow rate change is stored in the flow rate storage means 21 in time series. When a stable flow rate is continuously input from the flow rate calculation unit 20, the cycle setting unit 28 returns the cycle to the normal measurement cycle. The flow rate pattern storage unit 22 stores in advance a flow rate change pattern from the start of use of a typical instrument until the flow rate is stabilized. For example, the flow rate change pattern at the start of use of the instrument is roughly classified into gas consumption ranges of less than 5000 kcal / h, 5000 to 15000 kcal / h, and 15000 kcal / h or more. For each consumption range, that is, for each flow rate range, the sequence for each time, such as the start of use of the appliance, ignition, and the change in gas amount after detection of ignition, is roughly determined. I remember it. When the comparison determination unit 23 stores a flow rate value in a time series for a predetermined time in the flow rate storage unit 21, the comparison determination unit 23 compares and collates data in the flow rate pattern storage unit 22. The peak flow rate in the flow rate storage unit 21 is normalized and converted into the same scale as the peak flow rate in the flow rate pattern storage unit 22, and pattern matching is performed to check whether the time-series flow rate change pattern is within a standard deviation of a predetermined value. When the flow rate pattern and the detected flow rate change data are within a predetermined deviation, it is determined that the flow rate pattern and the detected flow rate match the device, and are output to the abnormality determination means 25 as a device signal. In parallel, the average flow rate calculation means 24 performs an averaging process from the time-series flow rate signals stored in the flow rate storage means 21 to obtain an average flow rate as a representative flow rate value.

  Further, when the flow rate pattern does not match with the various flow rate patterns in the entire flow rate range, when the standard deviation is larger than the predetermined value and deviates, it is determined that the device is not an instrument and an abnormality signal is output to the abnormality determination means 25. There are accident cases where the rubber hose is gnawed by a mouse or the like, causing gas leakage, but the flow rate change pattern at the time of gas detection in this case does not apply to any change in the flow rate of the instrument and can be detected immediately, and an abnormal signal is generated. The comparison determination means 23 outputs the result to the abnormality determination means 25.

  Next, from the appliance signal input from the comparison determination means 23 and the flow rate obtained from the average flow rate calculation means 24, the abnormality determination means 25 determines whether the appliance is in an abnormal use state. The abnormality determination means 25 divides the determination flow rate between the maximum flow rate usable in the gas shut-off device and the abnormal large flow rate due to hose disconnection, etc., and the flow rate range usable in the gas shut-off device to correspond to each flow rate range It has a usage time setting value. The abnormality determination unit 25 compares the flow rate calculated by the flow rate calculation unit 20 with the set abnormality determination flow rate to determine whether or not the flow rate has been exceeded. Compare with the value to determine whether it is in an abnormal long-time use state. For example, a use time cut-off table that defines a time limit for use time corresponding to a case where an appliance such as a stove is used much longer than the maximum use time for normal use is stored in the abnormality determination means 25. Monitors instrument flow. When the abnormality determining means 25 determines that an abnormality has occurred, a cutoff signal is output to the cutoff means 26 to shut off the gas flow path 1.

  On the other hand, when an abnormal signal such as leakage is input from the comparison / determination unit 23, the abnormality determination unit 25 immediately determines that the gas use state is abnormal, and drives the blocking unit 26 to stop the gas supply. When shut off, the shut-off state and the content of the shut-off are displayed on the liquid crystal display element of the informing means 27, and at the same time, a telephone line or the like is notified to the center that is monitoring the safety of the gas.

  When a flow rate change is detected by the flow rate detection means 14 during flow rate measurement in the flow path 1 in which the gas shut-off device is installed in this way, the flow rate change means is precisely measured in a short measurement cycle by the cycle setting means 28. The flow rate value precisely calculated by the calculation means 20 is stored in the flow rate storage means 21 in time series, and compared with the instrument flow rate change pattern stored in the flow rate pattern storage means 22 in advance, the flow rate is abnormal or an abnormal flow rate such as leakage. It can be accurately judged, and it can be shut off immediately when it is judged that it is not the flow rate of the appliance, etc. Without being filled with gas and leading to the worst abnormal state such as gas explosion or fire, it is possible to immediately identify whether it is a leak or an instrument and shut it off, so the instrument and leak monitoring are accurate and the gas usage status can be grasped. All sex and reliability is improved.

  As described above, the gas shut-off device according to the present invention is a water meter that measures various media flowing in the flow path using ultrasonic waves, for example, a liquid such as water, and an electric power that measures the amount of electricity and integrates the amount used. It can also be applied to uses such as meters.

FIG. 1 is a control block diagram of the gas cutoff device according to Embodiment 1 of the present invention. Control block diagram of gas cutoff device of embodiment 2 of the present invention Control block diagram of a conventional gas shut-off device

Explanation of symbols

14 Flow rate detection means 20 Flow rate calculation means 21 Flow rate storage means 22 Flow rate pattern storage means 23 Comparison determination means 24 Average flow rate calculation means 25 Abnormality determination means 26 Blocking means 28 Period setting means

Claims (3)

A flow rate detecting means for measuring a signal propagation time in the medium and detecting a flow rate; a flow rate calculating means for converting the flow rate to a flow rate detected by the flow rate detecting means; and a change in flow rate value when a flow rate change is detected by the flow rate calculating means. Is stored in time series, flow rate pattern storage means for storing a change in flow rate of the instrument to be compared with the change in flow rate stored in the flow rate storage means, and the flow rate storage means and the flow rate pattern storage means are compared with each other. Comparison determining means for specifying, average flow calculating means for obtaining an average flow rate from the stored flow rate of the flow rate storing means when the appliance is specified by the comparison determining means, and determining whether or not the flow value of the average flow calculating means is abnormal A gas shut-off device comprising: an abnormality determining unit; and a blocking unit that stops medium supply when an abnormality is determined by the abnormality determining unit. A flow rate detecting unit for measuring a signal propagation time in the medium and detecting a flow rate; a flow rate calculating unit for converting the flow rate from the flow rate detected by the flow rate detecting unit; and a cycle setting unit for variably setting a driving cycle of the flow rate detecting unit A flow rate storage unit that stores a change in flow rate value when a flow rate change is detected by the flow rate calculation unit, a flow rate pattern storage unit that stores a change in the instrument flow rate compared with the flow rate change stored in the flow rate storage unit, and the flow rate Comparison determining means for comparing the storage means and the flow rate pattern storage means to specify the appliance, average flow rate calculating means for obtaining an average flow rate from the stored flow rate of the flow rate storage means when the appliance is specified by the comparison determination means, and the average flow rate A gas shut-off device comprising: an abnormality judging means for judging whether or not the flow rate value of the computing means is abnormal; and a shut-off means for stopping the medium supply when judged abnormal by the abnormality judging means . A program for causing a computer to function as all or part of means of the gas shut-off device according to claim 1.

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