JP5305518B2 - Gas shut-off device - Google Patents

Description

  The present invention relates to a gas shut-off device that detects the presence or absence of internal pipe leakage.

  Conventionally, there has been a gas shut-off device of this type as shown in FIG. The gas shut-off device includes a flow rate measuring unit 3, a calculating unit 6, and a display unit 4. The display unit 4 is supplied from a gas container (not shown) as a gas supply source to a gas appliance (not shown). The gas flow rate is counted (integrated display). In order to determine the leakage, the leakage determining means 13 for determining leakage, the blocking means 2 for blocking the gas supply from the gas container to the gas appliance by closing the valve, the valve driving means 14 for driving the blocking means 2 The time measuring means 12 for counting the predetermined time is provided.

  In the above configuration, the leakage determination means 13 is based on the timing pulse output from the time measurement means 12, etc., every time a predetermined time elapses, the maximum value Qmax and the minimum value Qmin of the flow rate value Q detected during that time. The difference ΔQ = Qmax−Qmin is calculated, the value of the difference ΔQ is compared with a predetermined difference threshold value ΔQth, and the value of the difference ΔQ exceeds the difference threshold value ΔQth. In this case, it is determined that there is no inner pipe leakage. If the difference ΔQ is equal to or smaller than the difference threshold value ΔQth, the average value Qave of the flow rate values within the predetermined time is further calculated, and the average is calculated. When the value Qave is compared with a predetermined average flow rate threshold value and the average value Qave of the flow rate value Q exceeds the average flow rate threshold value aveQth, it is determined that there is no internal pipe leakage, and the average value of the flow rate value Q Qave is the average flow rate If was below threshold aveQth determines an inner tube leakage.

  With the above configuration, even when a pulsation caused by a nearby gas device occurs via a common pipe or the like, it can be prevented from being erroneously detected as a gas leak (see, for example, Patent Document 1).

  Moreover, when using a device with a spark, there is a device in which a spark flow is registered in advance so that it is not erroneously detected as an inner pipe leak (for example, see Patent Document 2). The configuration will be described below with reference to FIG.

  FIG. 11 is a timing chart showing the operation of the conventional flame flow rate measuring device. In the allowable flow rate range where the gas flow rate calculation values Qh to Ql are set, a flow rate equal to or higher than the first predetermined value Qp is detected at the timing of time t0. Since the minimum flow rate Qmin from t0 to t1 is within the set allowable flow rate range, that is, Qh to Ql, until the time t1 when the timing ends, Qmin is registered as the ignition flow at time t1.

With the above-described configuration, the amount of gas combustion equivalent to an open flame is registered and can be effectively used in connection with the detection of leaks in the inner pipe.
JP 2002-156304 A Japanese Examined Patent Publication No. 6-92903

  However, in the conventional configuration, when a large combustion device such as GHP is installed in the vicinity, the pulsation is intense, so it is judged that the inner pipe is leaked, or conversely, the threshold is changed and the pulsation is erroneous. If it is not judged, even if a leak actually occurs, it can not be detected, or if it is not possible to register a fire due to pulsation and a device with a fire is used, it is misjudged as an inner pipe leak, Even if it is possible to register the flaming, the minimum pulsation flow rate, which is a lower flow rate, is registered instead of the original flaming flow rate, and when the pulsation is stopped, the fire flow rate is erroneously determined as an inner pipe leak. It was.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a gas shut-off device that can correctly detect an inner pipe leak even if there is a pulsation, and can reliably perform flaming registration.

  In order to solve the above-described conventional problems, a gas shutoff device according to the present invention includes an external communication unit connected to a gas supply pipe and capable of communicating with the outside, a control unit for controlling the external communication unit, and a gas flow rate. A flow rate measuring means for measuring at regular time intervals, a calculation means for obtaining a flow rate value by output from the flow rate measurement means, a flaming determination means for determining whether or not there is a fire from the flow rate value calculated by the calculation means, and a calculation means The calculated flow rate value is accumulated for a predetermined time to calculate the section average flow, and the section calculation means for selecting the maximum flow and the minimum flow therebetween, and the presence / absence determination of the flow based on the output from the section calculation means Means for determining whether or not the flow rate has been continued a predetermined number of times while the difference between the maximum flow rate and the minimum flow rate from the interval calculation means is within a predetermined allowable range and the average flow rate is within a predetermined allowable range. If the average of the average flow rate is within the average judgment flow rate, it is determined that there is no flow rate, and the inner pipe leak judgment timer is initialized. It is set as the structure to do. In addition, with regard to the flaming registration necessary for the determination of the inner pipe leakage, the flaming registration is surely performed even under pulsation by determining the difference between the previous section average flow rate and the current section average flow rate and the ratio thereof. It is a thing.

  As a result, even in an environment where pulsation due to GHP or the like occurs, it is possible to prevent an erroneous determination that an inner pipe leakage warning is generated even though there is no actual leakage. In addition, it can be registered reliably in the flaming registration, and it is possible to prevent misjudgment of inner pipe leakage after the flaming registration, to eliminate the user's anxiety due to false warnings, and to unnecessarily dispatch gas companies Can be prevented.

  The first invention is an external communication means connected to a gas supply pipe and capable of communicating with the outside, a control means for controlling the external communication means, a flow rate measuring means for measuring a gas flow rate at a constant time interval, Calculation means for obtaining a flow rate value by output from the flow rate measurement means, ignition determination means for determining whether or not there is a fire from the flow rate value calculated by the calculation means, and the flow rate value calculated by the calculation means for a predetermined time The flow rate calculation unit includes a zone calculation unit that accumulates and calculates a zone average flow rate, and selects a maximum flow rate and a minimum flow rate therebetween, and a flow rate presence / absence determination unit that determines the presence or absence of a flow rate based on an output from the zone calculation unit. The presence / absence determining means is such that the difference between the maximum flow rate and the minimum flow rate from the section calculation means is less than the allowable determination range and the average section flow is within the allowable determination range + the allowable determination range shift amount every predetermined time. If there is, the section average flow rate is accumulated, the average flow rate is calculated when the first judgment count is accumulated, and if the calculated average flow rate is within the average judgment flow rate, it is determined that there is no flow rate and the inner pipe leaks The determination timer is initialized, and when it is determined that there is a flow rate other than that and continues for a predetermined period, the inner pipe leakage is confirmed.

  Thereby, by determining the average of the number of determinations of the section average flow rate, it is possible to stably determine that there is no flow rate even under pulsation, and to prevent an erroneous warning of inner pipe leakage.

  In the second invention, in particular, the flow rate presence / absence determining means according to the first invention is such that the difference between the maximum flow rate and the minimum flow rate from the section calculating means is less than the determination allowable range and the section average flow rate is determined allowable after the flares registration. If it is within the range, the section average flow rate is accumulated, and when the second determination times are accumulated, the average flow rate is calculated, and the difference between the calculated average flow rate and the ignited registered flow rate is the predetermined ratio of the registered flow rate or the average When it falls within the judgment flow rate, it is judged that there is no flow rate and initializes the inner pipe leak judgment timer. is there.

  As a result, it is possible to stably determine that there is no flow even under pulsation by determining the difference between the average for the number of determinations of the average flow rate of the section after the flares registration and the flares registered flow, and the inner pipe leakage Can prevent false alarms.

  In the third aspect of the invention, in particular, when the ignition determination means of the first aspect of the invention is inputted with an ignition registration start request from the external communication means, the zone average flow rate from the zone calculation means is within a predetermined flame registration flow rate range and The difference between the maximum flow rate and the minimum flow rate from the section calculation means is continuously accommodated twice within the first differential flow rate, and the difference between the previous section average flow and the current section average flow is the previous section average flow. When it becomes within the first predetermined ratio or within the predetermined flow rate, the average flow rate of the previous zone average flow rate and the current zone average flow rate is registered as the igniting registered flow rate.

  As a result, by determining the difference between the previous average flow rate and the current average flow rate and the ratio thereof, it is possible to perform the on-site burning registration reliably even under pulsation.

  According to a fourth aspect of the present invention, in particular, when there is no flaming registration start request from the external communication means, the flaming judgment means of the first invention is such that the section average flow rate from the section calculation means is a predetermined flaming. Within the registered flow rate range, the difference between the maximum flow rate and the minimum flow rate from the interval calculation means is continuously accommodated twice within the second differential flow rate, and the difference between the previous interval average flow rate and the current interval average flow rate is When the average flow rate is within the first predetermined ratio or within the predetermined flow rate, the average flow rate between the previous average flow rate and the current average flow rate is used as the temporary crater registration flow rate, The sum of the previous section average flow and the current section average flow is stored in the adding means, and after the provisional crater registration, the difference between the section average flow from the section calculation means and the provisional bonfire registration flow is determined. Within the allowable range and the interval calculation When the difference between the maximum flow rate and the minimum flow rate falls within the second differential flow rate, the section average flow rate is added to the adding means, and when the third determination number is reached, the average of the flow rates added to the adding means When the calculated average flow rate is within the registered flow rate range, the calculated average flow rate is registered as the ignited registered flow rate.

  As a result, by determining the average for the number of determinations of the section average flow after the provisional igniting flow rate registration and the provisional igniting flow rate registration, automatic registration of the igniting can be performed reliably even under pulsation.

  A fifth invention is a program for causing a computer to function as all or part of the gas shut-off device according to any one of the first to fourth inventions. And since it is a program, at least one part of the program of this invention is easily realizable using a general purpose computer or a server. Also, program distribution and installation can be simplified by recording on a recording medium or distributing a program using a communication line.

  Since the present invention can achieve the object of the present invention by making the main parts of the first to fourth inventions into embodiments, the details of the embodiments corresponding to each claim will be described below with reference to the drawings. The description will be given with reference to the best mode for carrying out the present invention. Note that the present invention is not limited to the present embodiment. Further, in the description of each embodiment, the same configuration and the same function and effect are given the same reference numerals, and redundant description will not be given.

(Embodiment 1)
FIG. 1 shows a block diagram of a gas meter as a gas shut-off device in the first embodiment of the present invention.

  In FIG. 1, a gas meter device 1 is provided in the middle of a gas supply pipe, and one or more gas appliances installed in each customer's house are connected to a downstream pipe.

  In FIG. 1, the gas meter device 1 includes a flow rate measuring unit 3, a calculation unit 6, a fire discrimination unit 7, a section calculation unit 8, a flow rate presence / absence determination unit 9, a control unit 10, a display unit 4, a seismic device 5, and a cutoff unit 2. The external communication means 11 is configured. The flow rate measuring means 3 is connected in the path of the gas supply pipe a and, as will be described later, obtains a propagation time difference caused by the gas flow in the gas supply pipe a by using an ultrasonic signal, and detects an instantaneous gas flow rate. Is. The calculating means 6 calculates the gas flow rate by integrating the instantaneous flow rate based on the detected instantaneous flow rate. The flow rate measurement means 3 and the calculation means 6 realize the function of the flow rate measurement unit.

  The spark determination means 7 determines the spark for registering the spark flow based on the calculated flow value.

  The section calculation means 8 accumulates the calculated flow rate value for a predetermined time to calculate a section average flow rate, or selects the maximum flow rate and the minimum flow rate during that time.

  The flow rate presence / absence determining means 9 performs a flow rate presence / absence determination process for determining inner pipe leakage from the section average flow rate and the maximum flow rate and the minimum flow rate therebetween at predetermined time intervals.

  In addition to controlling the operation of each part in the gas meter device 1, the control means 10 performs a flow rate presence / absence determination result by the flow rate presence / absence determination unit 9 and a safety process such as a warning by shutting off the inner pipe and shutting off the gas.

  Here, the control means 10, the calculation means 6, the ignition determination means 7, the section calculation means 8, and the flow rate presence / absence determination means 9 are configured by a processor and an operation program that constitute a microcomputer (microcomputer) and the like, and a predetermined operation in the processor. Each function is realized by executing a program and performing a corresponding process.

  In addition, regarding the flow rate measuring means 3 of the present invention, an ultrasonic type measuring means is used. However, as a measuring method, other flow rate measuring methods can be continuously measured in a constant cycle in a short time such as a fluidic method. If it is.

  The display unit 4 includes an LED, a liquid crystal display, and the like, and displays a gas flow rate, an operating state of the gas appliance, a warning, and the like. The seismoscope 5 detects vibration such as an earthquake and outputs a detection signal to the control means 10. The shut-off means 2 is connected to the path of the gas supply pipe a, and shuts off the gas supply by closing the gas supply pipe a based on an instruction from the control means 10.

  The external communication means 11 has a wired or wireless communication function, and is connected to a management center (not shown) via a public line, for example. The external communication unit 11 exchanges various information, commands, and signals with the management center.

  The management center is configured to include a computer and the like, and realizes the function of the management unit. The management center includes a processor and an operation program that configure the computer and the like, and performs a corresponding process by executing a predetermined operation program in the processor. Thus, each function is realized.

  The operations of the flow rate measuring means 3 and the calculating means 6 will be described in detail. FIG. 2 is a configuration diagram showing a schematic configuration of the flow rate measuring means 3.

  The flow rate measuring means 3 has a measurement flow path 32 having a rectangular cross section communicating with the gas supply pipe a, and a pair of ultrasonic waves is provided on the upstream side and the downstream side of the flow path walls facing each other. Transceivers 33 and 34 are arranged. These ultrasonic transmitters / receivers 33 and 34 are set so that the ultrasonic propagation path obliquely crosses the gas flow flowing through the measurement flow path 32, and the ultrasonic flow is alternately transmitted / received, so that the ultrasonic flow is sequentially transmitted and received. Propagation of ultrasonic waves in the opposite direction.

At this time, the distance between the ultrasonic transceivers 33 and 34, that is, the measurement distance is L, the angle of the ultrasonic propagation path with respect to the gas flow is φ, and the ultrasonic propagation time from the upstream to the downstream of the ultrasonic transceivers 33 and 34 is If t1, the ultrasonic propagation time from downstream to upstream is t2, and the sound velocity is C, the flow velocity V can be obtained by the following equation.
V = L / 2 cos ((1/1/1)-(1 / t2))
The instantaneous flow rate of the gas flow is calculated from the flow velocity V and the cross-sectional area of the measurement channel 32.

  The time interval for measuring the instantaneous flow rate can be set within a range where ultrasonic waves can be transmitted and received. Since the time to change by activation and control differs depending on the gas appliance, reducing the measurement time interval is advantageous in that the instrument discrimination is performed instantaneously, but shortening the measurement time interval increases battery consumption. . Further, when the measurement time interval is a two-digit order interval equivalent to the membrane type used in the conventional gas meter, it becomes difficult to judge by looking at the difference in flow rate change. Therefore, in this embodiment, when the gas appliance is not used, the periodic instantaneous flow rate is measured at intervals of 2 seconds, and the difference value is taken to determine the activation of the gas appliance. The measurement time interval can be further shortened. For example, after starting the gas appliance, control such as shortening the measurement time interval may be performed in order to increase measurement accuracy.

  Next, the operation of the flow rate presence / absence determining means 9 will be described in detail. FIG. 3 is a characteristic diagram showing a change in gas flow rate during pulsation, and FIG. 4 is a diagram showing an allowable determination range of the section average flow rate Qt.

  FIG. 3 shows the instantaneous flow rate value of the gas measured by the flow rate measuring means 3. If the flow rate is stable near zero when the gas appliance is not used, it is easy to determine that there is no flow rate, and if it is stable at a very small flow rate, it is easy to detect leakage of the inner pipe. However, when pulsation occurs due to the influence of GHP or the like, the flow rate is not stable, so it can not be determined that there is no flow rate. There was a problem that it was judged. Therefore, in order to determine that there is no flow rate under pulsation, the maximum value Qtmax and minimum value Qtmin of the flow rate for a certain predetermined time and the average of the flow rate within the predetermined time are obtained and set as the section average flow rate Qt, and the degree of stability under pulsation is determined. Used for. FIG. 4 shows threshold values for determining the degree of stability of the section average flow rate Qt. Assuming that the determination allowable range Qh and the determination allowable range shift width Qs are (−Qh + Qs) to (Qh + Qs), the determination threshold is set. If it is out of this range, there is a flow rate. The determination allowable range shift width Qs is provided in consideration of the change in the offset of the flow rate measuring means 3 with respect to the secular change. FIG. 5 is a diagram obtained by plotting the section average flow rate Qt within the range of (−Qh + Qs) to (Qh + Qs), which is the determination threshold shown in FIG. If the average flow rate of the section average flow rate for the first determination count is not within the average determination flow rate, it is determined that there is a flow rate.

  FIG. 6 is a flowchart showing an operation procedure for determining whether or not there is a flow rate according to this embodiment. The flow rate presence / absence determination 9 stores a program for executing the control flow of steps (hereinafter referred to as S) 1 to S13 shown in FIG.

  First, in S1, it is determined whether or not the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin from the section calculation means 8 is less than the allowable range width at every predetermined time. In S2, it is determined whether or not the section average flow rate Qt from the section calculation means 8 is equal to or less than the allowable determination range + the allowable determination range shift width. If it is larger than the judgment range tolerance + judgment tolerance range shift width, the inner pipe leakage judgment timer is increased with the flow rate (S3). In S4, it is judged whether the inner pipe leakage judgment timer has reached a predetermined value, and the predetermined value is reached. When it reaches, the inner pipe leakage is confirmed (S5).

  In S6, the section average flow Qt from the section calculation means 8 is added to the total flow, and in S7, the continuous number counter is increased. In S8, it is determined whether or not the continuous number counter has reached the first determination number. If reached, the process proceeds to S9, and if not, the process proceeds to S3. In S9, the continuous number counter is cleared. In S10, the average flow rate is calculated using the total flow rate obtained by adding the section average flow rate Qt by the first determination number in S6. In S11, the total flow rate is cleared. In S12, it is determined whether or not the absolute value of the average flow rate calculated in S10 is within the average determination flow rate. If it is within the average determination flow rate, the flow proceeds to S13 as no flow rate, and if not within the average determination flow rate, the flow proceeds to S3. In S13, the inner pipe leakage determination timer is cleared.

  As described above, in the present embodiment, it is possible to stably determine that there is no flow rate even under pulsation, and to prevent an erroneous warning of inner pipe leakage.

(Embodiment 2)
FIG. 7 is a flowchart showing an operation procedure of the flow rate presence / absence determination of the present embodiment. The present embodiment differs from the first embodiment in the flow rate presence / absence determining means 9 shown in FIG. 1 only in the program, and the block diagram of the gas cutoff device is the same as FIG. That is, the flow rate presence / absence determining means 9 stores a program for executing the control flow from S14 to S40 shown in FIG.

  In S14, it is determined whether or not the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin from the section calculation means 8 is less than the allowable range width every predetermined time. In S15, it is determined whether or not the section average flow rate Qt from the section calculation means 8 is equal to or less than the allowable determination range + the allowable determination range shift width. If it is larger than the judgment range tolerance + the judgment tolerance range shift width, a flag indicating that there is a flow rate is set (S16), and the process proceeds to S17. In S24, the section average flow Qt from the section calculator 8 is added to the first total flow, and in S25, the first continuous number counter is increased. In S26, it is determined whether or not the first continuous number counter has reached the first determination number. If reached, the process proceeds to S27, and if not, the process proceeds to S16. In S27, the first continuous number counter is cleared. In S28, the first average flow rate is calculated using the first total flow rate obtained by adding the section average flow rate Qt by the first determination number in S24. In S29, the first total flow rate is cleared. To do. In S30, it is determined whether or not the absolute value of the first average flow rate calculated in S28 is within the average determination flow rate. If within the average determination flow rate, the process proceeds to S31, and if not within the average determination flow rate, the process proceeds to S16. In S31, the flow rate flag is cleared and the process proceeds to S17. In S17, it is determined whether or not there is a flaming registration. If there is no flaming registration, the process proceeds to S20, and if there is a flaming registration, it is determined whether or not the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin from the section calculation means 8 is less than the allowable range width. If it is not less than the allowable range, the process proceeds to S20. In S19, it is determined whether or not the section average flow rate Qt from the section calculation means 8 is within the ignited registered flow rate ± judgment allowable range. If it is within the firing registration flow rate ± determination allowable range, the zone average flow rate Qt from the zone calculation means 8 is added to the second total flow rate (S32), and in S33, the second continuous number counter is increased. In S34, it is determined whether or not the second continuous number counter has reached the second determination number. If it has reached, the process proceeds to S35, and if not, the process proceeds to S20. In S35, the second continuous number counter is cleared. In S36, the second average flow rate is calculated using the second total flow rate obtained by adding the section average flow rate Qt by the second determination number in S32. In S37, the second total flow rate is cleared. To do. In S38, it is determined whether or not the absolute value of the difference between the second average flow rate calculated in S36 and the ignited registered flow rate is within the average determination flow rate. If it is within the average determination flow rate, the process proceeds to S40. move on. In S39, it is determined whether or not the absolute value of the difference between the second average flow rate and the ignited registered flow rate is less than or equal to a predetermined ratio of the ignited registered flow rate. If it is below, the inner pipe leakage determination timer is cleared with no flow (S40). In S20, it is determined whether the flow rate flag is set. If the flow rate flag is not set, the flow proceeds to S40 as no flow rate, and if the flow rate flag is set, the inner pipe leakage determination timer is set as flow rate. Up (S21). In S22, it is determined whether or not the inner pipe leakage determination timer has reached a predetermined value. When the predetermined value is reached, the inner pipe leakage is determined (S23).

  In addition, in this embodiment, although the case where there was one flaming registration was demonstrated, when there are several flaming registrations, it implement | achieves by processing the process of S17 to S19 and S32 to S39 for every each flaming. it can.

  As described above, in the present embodiment, it is possible to determine that there is no flow rate stably even under pulsation registration and to prevent an erroneous warning of inner pipe leakage.

(Embodiment 3)
FIG. 8 is a flowchart showing the operation procedure for the registration of the fire site according to the present embodiment. The present embodiment is different from the ignition determination means 7 shown in FIG. 1 in the first embodiment only in the program, and the block diagram of the gas cutoff device is the same as FIG. That is, the scoring determination means 7 stores a program for executing the control flow from S41 to S47 shown in FIG.

  When a flaming registration start request is input from the external communication means 11, it is determined in S41 whether or not the section average flow rate Qt from the current section calculation means 8 is within the registered flow rate range. It is determined whether or not the flow rate Qt-1 is within the registered flow rate range (S42). If the previous section average flow rate Qt-1 is within the registered flow range, it is determined whether the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin from the current section calculation means 8 is less than the first differential flow rate (S43). If it is less than 1 difference flow rate, it is determined in S44 whether the difference between the previous maximum flow rate Qt-1max and the minimum flow rate Qt-1min is less than the first difference flow rate. It is determined whether the absolute value of the difference between the flow rate Qt and the previous segment average flow rate Qt-1 is less than a predetermined ratio of the previous segment average flow rate Qt-1 (S45), and a predetermined ratio of the previous segment average flow rate Qt-1 If not, the process proceeds to S47, and if it is not less than the predetermined ratio of the previous section average flow rate Qt-1, is the absolute value of the difference between the current section average flow rate Qt and the previous section average flow rate Qt-1 less than the predetermined flow rate? Judge whether or not (S4 ), If less than a predetermined flow rate, calculates the average of the section average flow rate Qt-1 of the average current interval flow Qt and the last in S47, and registers as a pilot flame registered flow rate.

  As described above, in the present embodiment, when performing site registration of a fire, it is possible to reliably perform the fire registration on site even under pulsation.

(Embodiment 4)
FIG. 9 is a flowchart showing the operation procedure of the automatic ignition registration of the present embodiment. The present embodiment is different from the ignition determination means 7 shown in FIG. 1 in the first embodiment only in the program, and the block diagram of the gas cutoff device is the same as FIG. That is, the scoring determination means 7 stores a program for executing the control flow from S48 to S67 shown in FIG.

  In S48, it is determined whether or not the temporary igniting flow rate registration flag is set. If the temporary igniting flow rate registration flag is set, the process proceeds to S59. If the flag with provisional igniting flow rate registration is not set, it is determined whether or not the section average flow rate Qt from the current section calculating means 8 is within the registered flow range (S49). It is determined whether Qt-1 is within the registered flow rate range (S50). If the previous section average flow rate Qt-1 is within the registered flow range, it is determined whether the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin from the current section calculation means 8 is less than the second differential flow rate (S51). If it is less than 2 differential flow rates, it is determined in S52 whether the difference between the previous maximum flow rate Qt-1max and the minimum flow rate Qt-1min is less than the second differential flow rate. It is determined whether the absolute value of the difference between the flow rate Qt and the previous section average flow rate Qt-1 is less than a predetermined ratio of the previous section average flow rate Qt-1 (S53), and a predetermined ratio of the previous section average flow rate Qt-1 If not, the process proceeds to S55, and if it is not less than the predetermined ratio of the previous section average flow rate Qt-1, is the absolute value of the difference between the current section average flow rate Qt and the previous section average flow rate Qt-1 less than the predetermined flow rate? Judge whether or not (S5 ), If less than a predetermined flow rate, calculates the average of the section average flow rate Qt-1 of the average current interval flow Qt and the last in S55, and registers as temporary pilot flame registered flow rate. In S56, the sum of the current section average flow Qt and the previous section average flow Qt-1 is stored in the third total flow. In S57, 2 is stored in the check counter as an initial value, and a provisional flaming registration flow rate flag is set (S58). In S59, it is determined whether or not the absolute value of the difference between the section average flow rate Qt and the provisional crater registered flow rate is equal to or smaller than the determination allowable width. If it is equal to or smaller than the determination allowable width, the process proceeds to S60. In S60, it is determined whether the difference between the maximum flow rate Qtmax and the minimum flow rate Qtmin is less than the second differential flow rate. If the difference is less than the second differential flow rate, the process proceeds to S61. In S61, the check counter is increased. In S62, the section average flow rate Qt is added to the third total flow rate. In S63, it is determined whether the check counter has reached the third determination number. A third average flow rate is calculated using the flow rate. In S65, it is determined whether or not the third average flow rate is within the registered flow rate range. If it is not within the registered flow rate range, the process proceeds to S67. If it is within the registered flow rate range, the third average flow rate calculated in S64 is registered as the ignited registered flow rate. (S66). In S67, the provisional flame flow registration flag is cleared.

  As described above, in the present embodiment, it is possible to reliably perform automatic registration of fire even under pulsation.

  As described above, the gas shut-off device according to the present invention can be applied to a method for detecting leakage of water or gas because it can determine the leakage of the inner pipe even in an environment where pulsation occurs.

The block diagram of the gas meter in Embodiment 1-4 of this invention 1 is a schematic configuration diagram of an ultrasonic flow meter according to Embodiment 1 of the present invention. The figure which shows the instantaneous flow volume value of the gas in Embodiment 1 of this invention. The figure which shows the threshold value which determines the stability degree of the area average flow volume in Embodiment 1 of this invention. The figure which plotted the 1st determination frequency of the section average flow volume in Embodiment 1 of this invention The flowchart which shows the operation | movement procedure of the flow volume presence determination in Embodiment 1 of this invention. The flowchart which shows the operation | movement procedure of the flow volume presence determination in Embodiment 2 of this invention. The flowchart which shows the operation | movement procedure of the flaming site registration in Embodiment 3 of this invention The flowchart which shows the operation | movement procedure of the automatic ignition registration in Embodiment 4 of this invention Block diagram of a conventional gas meter that detects the presence or absence of internal pipe leakage Timing chart showing the operation of a conventional igniting flow meter

DESCRIPTION OF SYMBOLS 1 Gas meter apparatus 2 Blocking means 3 Flow measurement means 4 Display part 5 Seismic device 6 Calculation means 7 Firing determination means 8 Section calculation means 9 Flow existence determination means 10 Control means 11 External communication means

Claims (5)

  An external communication means connected to the gas supply pipe and capable of communicating with the outside, a control means for controlling the external communication means, a flow rate measuring means for measuring a gas flow rate at regular time intervals, and an output from the flow rate measuring means Calculating means for obtaining a flow rate value by means of the above, an ignition determining means for determining whether or not there is a fire from the flow value calculated by the calculating means, and the interval average flow rate by accumulating the flow value calculated by the calculating means for a predetermined time And a flow rate presence / absence determination unit that determines the presence / absence of a flow rate based on an output from the interval calculation unit. When the difference between the maximum flow rate and the minimum flow rate from the section calculation means for each time is less than the determination allowable range, and the section average flow rate is within the determination allowable range + determination allowable range shift amount The average flow rate is accumulated, and the average flow rate is calculated when the first judgment count is accumulated. If the calculated average flow rate is within the average judgment flow rate, it is determined that there is no flow rate and the inner pipe leakage judgment timer is initialized. Otherwise, it is determined that there is a flow rate, and if it continues for a predetermined period, the inner pipe leakage is confirmed, and the gas shut-off device is characterized in that   The flow rate presence / absence judging means accumulates the section average flow rate after the igniting registration, when the difference between the maximum flow rate and the minimum flow rate from the section calculation means is less than the judgment allowable range and the section average flow rate is within the judgment allowable range. When the second determination times are accumulated, the average flow rate is calculated, and when the difference between the calculated average flow rate and the ignited registered flow rate is within a predetermined ratio of the registered flow rate or within the average determination flow rate, there is no flow rate. 2. The gas shutoff device according to claim 1, wherein the internal pipe leakage determination timer is initialized and the flow rate is determined otherwise, and if the flow continues for a predetermined period, the internal pipe leakage is confirmed.   When the flaming registration start request is input from the external communication unit, the flaming judgment unit has a section average flow rate from the section calculation unit within a predetermined flaming registration flow range, and a maximum flow rate and a minimum flow rate from the section calculation unit. The difference between the previous average flow rate and the current average flow rate is within the first predetermined ratio or within the predetermined flow rate of the previous average flow rate. 3. The gas shutoff device according to claim 1, wherein an average flow rate between a previous section average flow rate and a current section average flow rate is registered as an igniting registered flow rate.   When there is no flaming registration start request from the external communication means, the flaming determination means has a section average flow rate from the section calculation means within a predetermined flaming registration flow rate range, and a maximum flow rate and a minimum flow rate from the section calculation means. The difference between the previous average flow rate and the current average flow rate is within the first predetermined ratio or within the predetermined flow rate of the previous average flow rate. In this case, the average flow rate of the previous segment average flow rate and the current segment average flow rate is used as the temporary crater registration flow rate, and the provisional crater registration is performed, and the sum of the previous segment average flow rate and the current segment average flow rate is added. After the provisional crater registration, the difference between the section average flow rate from the section calculation unit and the provisional crater registration flow rate is within the allowable determination range, and the maximum flow rate and the minimum flow rate from the section calculation unit are Difference is the second differential flow rate When the average flow rate added to the adding means is reached, the average flow rate added to the adding means is calculated and the calculated average flow rate is within the registered flow rate range. The gas cutoff device according to any one of claims 1 to 3, wherein the calculated average flow rate is registered as an ignited registered flow rate.   A program that causes a computer to function as all or part of the gas shutoff device according to claim 1.

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