JP2008008734A - Gas shutoff apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas shutoff apparatus which promptly detects an abnormal flow and stops medium supply such as gas. <P>SOLUTION: The gas shutoff apparatus detects a flow speed in piping by a flow speed detection means 8, converts it into a flow rate by a flow rate calculation means 14, stores an abnormal flow rate decision value of an instrument in use or the like in a flow rate abnormality storage means 16, determines an instantaneous flow rate estimated value by a flow rate estimation means 15 from an instantaneous flow rate determined by the flow rate calculation means 14, compares the instantaneous flow rate of the flow estimation means 15 with the abnormal flow rate decision value of the flow abnormality storage means 16, and stops the medium supply by a shutoff means 18 when an abnormality decision means 17 decides that the instantaneous flow rate estimated value is larger than a flow rate abnormality storage value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas shut-off device that detects the flow rate of various media flowing in a pipe using ultrasonic waves, such as city gas and LP gas, and monitors whether the gas usage state is safe based on the total flow rate.

  Conventionally, this type of gas shut-off device has a configuration shown in FIGS. 2 and 3 as disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-207965 (see, for example, Patent Document 1).

  FIG. 2 shows a block diagram of a conventional gas shut-off device. In FIG. 2, reference numeral 1 denotes a flow rate monitoring unit that monitors the flow rate of gas flowing through the gas flow path using an ultrasonic sensor, a flow sensor, or the like, and detects an instantaneous flow rate. Reference numeral 2 denotes a data calculation unit, which is supplied with detection output from the flow rate monitoring unit 1 by sampling at a predetermined time interval, calculates an instantaneous flow rate based on the detection output, and moves to the instantaneous flow rate measurement value at a predetermined time interval. Processing is performed to calculate the moving average flow rate. A data storage unit 3 stores the instantaneous flow rate and the moving average flow rate calculated by the data calculation unit 2. Reference numeral 4 denotes a cutoff value storage unit that stores in advance a preset cutoff value of the total flow cutoff function. This cutoff value includes a first cutoff value Rth1 compared with the moving average flow rate and a second flow rate Rth2 compared with the instantaneous flow rate. A data comparison unit 5 compares the instantaneous flow rate and moving average flow rate stored in the data storage unit 3 with the cutoff value stored in the cutoff value storage unit 4, and outputs an abnormality detection signal as a comparison result. A control unit 6 outputs an instruction signal that instructs the flow rate monitoring unit 1 to perform flow rate sampling at predetermined time intervals. In response to the input of the abnormality detection output from the data comparison unit 5, a cutoff signal is output. Reference numeral 7 denotes a shut-off unit, which comprises a shut-off valve controlled by a shut-off signal from the control unit 6.

  Next, the operation of the configuration of the conventional example will be described. First, the instantaneous flow rate Rn is measured. When measuring the flow rate, the control unit 6 instructs the flow rate monitoring unit 1 to perform flow rate sampling at predetermined time intervals. Thus, the flow rate detection signal from the flow rate monitoring unit 1 output at a predetermined time interval is calculated by the data calculation unit 2 to calculate the instantaneous flow rate Rn. Data of the calculated instantaneous flow rate Rn is sent to the data storage unit 3 and stored therein.

  Next, on the basis of the calculated instantaneous flow rate Rn, the moving average calculation process is performed in the data calculation unit 2 for every eight data shifted by one, and the moving average flow rate Ra is calculated. The calculated data of the moving average flow rate Ra is sent to the data storage unit 3 and stored therein. Next, whether or not the calculated moving average flow rate Ra is sent from the data storage unit 3 to the data comparison unit 5 and compared with the first cutoff value RTh1 stored in the cutoff value storage unit 4 is greater than it. Determine. When the moving average flow rate Ra is larger than the first cut-off value Rth1, an abnormality detection output is sent from the data comparison unit 5 to the control unit 6, whereby a drive output from the control unit 6 is sent to the cut-off unit 7 and the cut-off unit. 7 is used to shut off the gas.

  On the other hand, when the moving average flow rate Ra is smaller than the first cutoff value Rth1, the next calculated instantaneous flow rate Rn is sent from the data storage unit 3 to the data comparison unit 5 and stored in the cutoff value storage unit 4. It is compared with the cutoff value Rth2 of 2, and it is determined whether it is larger than that. When the instantaneous flow rate Rn is larger than the second cutoff value Rth2, the data comparison unit 5 increments the abnormal number counter. It is determined whether or not the incremented abnormality number counter has exceeded the specified number. If over, an abnormality detection output is sent from the data comparison unit 5 to the control unit 6, and a drive output is sent to the cutoff unit 7 to shut off the gas.

In this way, the set value of the flow rate cutoff is provided in two stages, the first cutoff value Rth1 and the second cutoff value Rth2, and the average flow rate Ra is compared with the first cutoff value Rth1, and the first cutoff value is determined. If exceeded, it will be blocked. In addition, the instantaneous flow rate Rn is monitored in parallel with the monitoring of the average flow rate Ra, and the instantaneous flow rate Rn exceeding the second cutoff value Rth2 higher than the first cutoff value Rth1 is continuously generated more than the specified number of times. In that case, a gas shut-off is performed.
JP 2005-207965 A

  However, the conventional configuration has the following problems. If trouble such as cracking of the piping for some reason or disconnection of the hose connected to the instrument occurs on the downstream side, it will be shut off if an abnormally large flow rate that exceeds that normally used by the instrument flows. When the moving average flow rate Ra does not reach the first cutoff value Rth1, and the instantaneous flow rate Rn does not reach the second cutoff value Rth2, the original cutoff value Rth1 However, since the second cutoff value Rth2 has not been reached, it cannot be shut off and is extremely dangerous. On the other hand, when the cutoff is judged, it is judged with an abnormally large cutoff value, so it cannot be shut down quickly, and the cutoff valve It is expected that the gas supply will be delayed and the gas supply will be delayed, the raw gas will leak, and the gas will fill the room under the floor or the living room, and the accident such as the worst explosion and fire may occur.

  The present invention solves the above-mentioned problems, and always detects an instantaneous flow rate, immediately identifies an abnormal flow rate caused by some cause, rather than judging with two types of determination flow rates, and immediately stops the gas supply. The object is to provide a gas shut-off device.

  In order to solve this problem, the present invention detects the flow rate in the pipe by the flow velocity detection means, converts the flow rate to the flow rate by the flow rate calculation means, stores the abnormal flow rate judgment value of the instrument used in the flow rate storage means, and calculates the flow rate. The instantaneous flow rate estimated value is obtained by the flow rate estimating means from the instantaneous flow rate obtained by the means, the instantaneous flow rate of the flow rate estimating means is compared with the abnormal flow judgment value of the abnormal flow rate memory means, and the instantaneous flow rate estimated value is larger than the abnormal flow rate stored value. If the abnormality determination means determines, the interruption means stops the medium supply.

  As a result, even if an abnormal and large amount of gas leaks, the abnormality can be determined at an early stage based on the original cutoff determination value, and the gas supply can be stopped immediately, so that the safety is greatly improved.

  According to the gas shut-off device of the present invention, the piping from the gas shut-off device to the appliance owned by the gas consumer, the hose connected to the fixture, etc. are disconnected for some reason or destroyed, and the gas is flowed at an abnormal flow rate. However, since the abnormal flow rate value is stored in advance in the flow rate abnormality storage means, the estimated value of the instantaneous flow rate that should be stabilized is obtained from the instantaneous flow rate value obtained by the flow rate calculation means, and compared with the abnormal value. Since the gas supply is immediately stopped by the shut-off means when it is determined that there is an abnormal leak, it does not take a long time to determine the abnormal flow rate, and as a result, there is no problem of accidents such as worst explosions or fires due to gas leaks. Since it can be shut off accurately and immediately without having a shut-off value, there is no risk of causing gas poisoning or fire, and the safety and reliability are greatly improved.

In order to achieve the above-mentioned object, the present invention provides a flow rate detection means for measuring a signal propagation time in a medium and detecting a flow rate, a flow rate calculation means for converting the flow rate from the flow rate detected by the flow rate detection means, and a tool used. An abnormal flow rate storage means for storing an abnormal flow rate judgment value, a flow rate estimation means for obtaining an instantaneous flow rate estimation value from an instantaneous flow rate obtained by the flow rate calculation means, an instantaneous flow rate of the flow rate estimation means and an abnormal flow rate judgment of the flow rate storage means And an abnormality determining means for comparing the value and determining the instantaneous flow rate estimated value obtained by the flow rate estimating means as a predetermined value and an abnormality at the time of determination, and a shutting means for stopping the medium supply at the time of the abnormality determination by the abnormality determining means. .

  And the gas table, gas fan heater, gas heat pump air conditioner (GHP) connected to the downstream side of the gas shut-off device, piping to the hot water heater, hose connected to the instrument may be disconnected or destroyed for some reason The gas is ejected at an abnormal flow rate, but the abnormal flow value is stored in advance in the flow rate storage means, and the estimated instantaneous flow rate to be stabilized is obtained from the instantaneous flow rate value obtained by the flow rate calculation means. Since the gas supply is immediately stopped by the shut-off means because it is compared with the value and the gas supply is immediately stopped, the abnormal flow rate determination does not take a long time, and as a result, there is a problem that the gas leak causes an accident such as a worst explosion or fire. Without having multiple shut-off values, it can be shut off accurately and immediately with the specified shut-off values according to the original standards, so there is no danger of the worst explosion or fire, and safety and reliability There is extremely improved. The invention described in claim 2 is a program for causing a computer to execute all or a part of the means of the gas cutoff device according to claim 1.

  And since it is a program, a part or all of the interruption | blocking apparatus of this invention can be easily implement | achieved using a microcomputer etc. Also, program distribution and installation can be simplified by recording on a recording medium or distributing a program using a communication line.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, components having the same functions as those in FIG.

(Embodiment 1)
FIG. 1 shows a gas shut-off device according to a first embodiment of the present invention. Reference numeral 8 denotes a flow velocity detecting means between an upstream vibrator 2 and a downstream vibrator 3 which are installed opposite to a flow path 1 of a gas medium such as LP. Then, an ultrasonic signal is transmitted from one to the other, and the flow rate of the gas used is detected from the propagation time. An example of the flow velocity detection means 8 is as follows. That is, the flow velocity detection unit 8 includes a switching unit 9, a transmission unit 10, a reception unit 11, a repetition unit 12, and a propagation time measurement unit 13. The transmission means 10 and the reception means 11 are connected to the switching means 9. The switching means 9 first connects the transmission means 10 to the upstream vibrator 2, the reception means 11 to the downstream vibrator 3, and then the transmission means 10. The connection destination of the transmission means 10 and the reception means 11 is alternately switched such that the transmission means 10 is connected to the downstream vibrator 3 and the reception means 11 is connected to the upstream vibration element 2. When the repeating means 12 is connected to the upstream vibrator 2 by the switching means 9 and the transmitting means 10 to the downstream vibrator 3, the ultrasonic signal transmitted from the transmitting means 10 is the upstream vibration. The signal is received by the receiving means 11 from the downstream vibrator 3 through the flow path 1 from the child 2, but the transmission to reception of the ultrasonic signal is repeated, and the signal propagation time is measured by the propagation time measuring means 13. The operation is repeated, but the number of times can be changed from one to any number of times. The propagation time measuring means 13 measures and accumulates the time from transmission to reception of the ultrasonic signal. Next, the receiving means 11 is connected to the downstream vibrator 3 and the transmitting means 10 is connected to the upstream vibrator 2 by the switching means 9, and the above operation is repeated. The propagation time measurement means 21 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 9 next.

  Reference numeral 14 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. Reference numeral 15 denotes a flow rate estimating means for obtaining a flow rate change value per unit time from the instantaneous flow rate from the flow rate calculating means 14, that is, estimating an instantaneous flow rate that is reached from a differential value of the instantaneous flow rate. Reference numeral 16 denotes an abnormal flow rate storage means for storing an abnormal flow rate value such as a hose disconnection or an abnormal flow rate judgment value that is not a normal flow rate of a gas appliance or the like. Reference numeral 17 denotes an abnormality determination unit that compares the instantaneous flow rate estimated value obtained by the flow rate estimation unit 15 with the abnormal flow rate determination value stored in the flow rate abnormality storage unit 16 to determine whether the flow rate is abnormal. If so, it is determined that the flow rate is abnormal such as hose disconnection. At this time, once the peak is detected by the appliance, it is stabilized after the peak is detected, but this peak detection and the estimated flow rate are used. When the instantaneous flow rate estimated value shows a stable value without detecting a peak in the abnormal state from the beginning, abnormality determination is performed with the flow rate estimated value.

  18 is a blocking means, and when the abnormality determining means 17 determines that the flow rate is abnormal, a blocking signal is output to block the gas flow path 1. 19 is an informing means. When the abnormality determining means 17 determines that the gas use state is abnormal and the shut-off means 18 is driven, the shut-off state and the shut-off content are displayed on the liquid crystal display element of the notifying means and the safety monitoring of the gas is performed. Report to the center where you are using 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 fluid pipe 1 of the gas shut-off device is a part of a long pipe, and the upstream vibrator 2 and the downstream vibrator 3 are installed obliquely in such a manner, and the flow rate is measured 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 to the downstream side of the gas shut-off device.

  Here, an example of the operation of the flow velocity detection means 8 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 transmitting means 10 is connected to the upstream vibrator 2 by the switching means 9, while the downstream vibrator 3 is connected to the receiving means 11, and the signal transmitted from the transmitting means 10 is transmitted from the upstream vibrator 2 to the downstream vibrator. 3 is received. This operation is performed as many times as set by the repeating means 12. The propagation time until the reception means 11 receives the ultrasonic signal emitted from the transmission means 10 is accumulated, and the propagation time measurement means 13 obtains the time.

  Next, the switching means 9 connects the transmitting means 10 to the downstream vibrator 3 and connects the receiving means 11 to the upstream vibrator 2. An ultrasonic signal is output from the transmitting means 10 and received by the receiving means 11 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 12 is performed. The propagation time until the reception means 11 receives the ultrasonic signal emitted from the transmission means 10 is accumulated by the propagation time measurement means 13, and further the propagation time when the ultrasonic signal is emitted from upstream to downstream, and 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 13 in the flow rate calculation means 14 is converted into a flow velocity value V and then converted into a flow value Q.

  Next, a flow rate change means, that is, a differential value is obtained by the flow rate estimation means 15 from the flow value obtained by the flow rate calculation means 14, and the instantaneous flow rate value to be stabilized is estimated. The abnormality determination unit 17 compares the flow rate abnormality determination value stored in the flow rate abnormality storage unit 16 in advance with the instantaneous flow rate estimation value. In the flow rate storage means 16, a large flow rate device such as a water heater, a gas dryer, a heating device such as a No. 5 instantaneous water heater, a fan heater, a cooking device such as a gas table, etc. are all used, or a plurality of uses. The flow rate value larger than the total flow rate value is set as the abnormal flow rate. The abnormality determination means 17 determines whether the estimated instantaneous flow rate is equal to or higher than the abnormal determination flow rate. At the start of use of the device, the initial pressure is generally high, and after a large flow rate is temporarily reached, the flow rate tends to decrease and stabilize. The flow rate estimation means 15 detects a change in flow rate with a positive gradient after detecting a flow rate present state, and the abnormality determination means 17 does not determine the instantaneous flow rate even if the estimated peak value exceeds the cutoff value. After the peak is detected by the flow rate estimation means 15, the flow rate decreases immediately thereafter, but the stabilized flow rate is estimated from the differential value of the flow rate. The abnormality determination unit 17 receives the peak signal and the flow rate estimated value from the flow rate estimation unit 15 and determines an abnormality based on the instantaneous flow rate estimated value. In particular, if the connection hose is accidentally disconnected during use of the device, an abnormal flow rate flows, or the piping is destroyed for some reason, and an abnormal flow rate is ejected, the instantaneous flow rate value for each flow rate sampling at the flow velocity detection means 8 is The flow rate estimating means 15 obtains a value at which the flow rate is to be stabilized at an early stage by estimating this state with a differential value, although it stabilizes quickly even if it falls below the peak value. In other words, since the abnormality determination means 17 determines at an early stage that the estimated and stable instantaneous flow rate value has exceeded the abnormality determination flow rate value, the interruption determination can be performed earlier than the abnormality determination based on the moving average flow rate.

  When the abnormality determining unit 17 determines that an abnormality has occurred, a cutoff signal is output to the blocking unit 18 to shut off the gas flow path 1. When shut off, the shut-off state and shut-off content are displayed on the liquid crystal display element of the informing means 19 and at the same time a communication message is sent via a telephone line to the center that is monitoring the safety of the gas.

  In this way, when measuring the flow rate in the pipe 1 where the gas shut-off device is installed, the abnormal instantaneous flow velocity by the flow velocity detection means 8 is continuously detected and converted by the flow rate calculation means 14, and the instantaneous value obtained by the flow rate estimation means 15. The instantaneous flow rate estimated to be more stable than the flow rate value is obtained, and when it is detected that it exceeds the instantaneous flow rate value stored in the flow rate storage means 16 in advance, it is determined that the flow rate is not normally used by an instrument or the like and is immediately detected. Output a blocking signal and detect the peak at the start of use of the instrument, estimate the stable flow rate thereafter, and determine whether the estimated value is abnormal or not, so that it is erroneously blocked depending on the characteristics of the instrument. Without interruption, judgment is made based on the standard that should be shut off with the instantaneous flow rate, and shuts off early, so that the abnormal flow rate is blown out for some reason, resulting in the gas filling the room and the worst abnormal state such as a gas explosion or fire Without reaching an early stage can determine the abnormal state safety and reliability is improved since the immediately shut off the gas supply.

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

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

Explanation of symbols

8 Flow rate detection means 14 Flow rate calculation means 15 Flow rate estimation means 16 Flow rate storage means 17 Abnormality determination means 18 Blocking means

Claims (2)

Flow rate detection means for measuring the signal propagation time in the medium and detecting the flow rate, flow rate calculation means for converting the flow rate from the flow rate detected by the flow rate detection means, and abnormal flow rate memory for storing abnormal flow rate judgment values such as used tools The flow rate estimating means for obtaining an instantaneous flow rate estimated value from the instantaneous flow rate obtained by the flow rate calculating means, and comparing the instantaneous flow rate of the flow rate estimating means with the abnormal flow rate judgment value of the flow rate storage means. A gas shut-off device comprising: an abnormality determining means for determining that the obtained instantaneous flow rate estimated value is a predetermined value and an abnormality at the time of determination; and an interrupting means for stopping the medium supply at the time of determination as abnormal by the abnormality determining means. A program for causing a computer to function as all or part of means of the shut-off device according to claim 1.

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