JP5578886B2 - Leakage location identification system and leakage location identification method - Google Patents

Description

  The present invention relates to a leak location specifying system and a leak location specifying method.

  2. Description of the Related Art Conventionally, there has been proposed a microleakage determination apparatus that determines whether or not microleakage has occurred in a housing facility that supplies fuel gas to a plurality of houses such as an apartment house. The housing facility includes a gas flow path that supplies fuel gas from a gas supply source to a plurality of houses, and a plurality of individual gas flow paths that supply the fuel gas flowing through the gas flow path to a plurality of houses. The minute leak determination device is provided on the gas flow path among the flow paths. Then, the minute leak judgment device judges that a minute leak has occurred when the fuel gas flows continuously for 30 days, for example, and issues an alarm or a call (see, for example, Patent Documents 1 and 2).

JP-A-3-41300 JP-A-5-296873

  However, in the conventional microleakage determination device, when a leak warning is given, the gas company is dispatched and the gas company itself identifies the leaked part, so that a lot of man-hours are required to identify the leaked part. In particular, when a gas company receives a leakage warning, it must inspect the individual gas flow paths and gas flow paths, and in the case of an apartment house with 100 or more houses, the specific man-hours of the leakage points are large. End up.

A leak location identifying system according to the present invention is a leak location identifying system for identifying a location where a slight leak occurs in a housing facility that supplies fuel gas from a gas supply source to a plurality of houses, and a plurality of fuel gases from a gas supply source. Gas passages to be supplied to the house side, a plurality of individual gas passages for supplying the fuel gas flowing through the gas passages to a plurality of houses, and the gas passages. a micro leakage determination unit for determining a minute leakage, provided on each of the plurality of individual gas flow channel, and a plurality of individual micro leakage determination unit for determining a minute leakage in each individual gas flow passages, said plurality individual At least one of the micro-leakage determination device and the micro-leakage determination device detects the micro flow rate when the micro flow rate is detected within a first predetermined time after the flow rate exceeding the micro flow rate is detected. Wherein the amount is determined not to be the flow rate by the minute leakage.

According to this leak location identifying system, since it includes a micro leak judgment device that judges micro leaks in gas flow paths and a plurality of individual micro leak judgment devices that judge micro leaks in each individual gas flow path, for example, a plurality of When leakage is determined by any one of the individual minute leakage determination devices, it can be determined that leakage has occurred in the individual gas flow path of the house. In particular, when it is determined that there are no leaks in a plurality of individual microleakage determination devices and there is a leak in the microleakage determination devices, it can be determined that a leak has occurred in the gas flow path instead of the individual gas flow paths. . As described above, from the result of the leakage determination of each device, it is possible to specify the approximate leakage location and simplify the specification of the leakage location. Furthermore, if a minute flow rate is detected within the first predetermined time after a flow rate exceeding the minute flow rate (for example, a flow rate of at least 50 L / h, preferably a flow rate of 100 L / h or more) is detected, Judge that the flow rate is not due to minute leakage. Here, in a gas appliance (for example, a gas stove or a gas table) that accompanies a torch, first, a large flow rate flows at the time of ignition, and then a slight flow rate tends to flow by adjusting the heating power to become a torch. In this way, the flow rate of the gas appliance accompanied with a hot flash shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate is not due to minute leakage but due to hot fire. Therefore, when such a flow rate transition is observed, it is possible to improve the determination accuracy of the minute leak by determining that the minute flow rate is not due to the minute leak.

  According to this leak location identifying system, since it includes a micro leak judgment device that judges micro leaks in gas flow paths and a plurality of individual micro leak judgment devices that judge micro leaks in each individual gas flow path, for example, a plurality of When leakage is determined by any one of the individual minute leakage determination devices, it can be determined that leakage has occurred in the individual gas flow path of the house. In particular, when it is determined that there are no leaks in a plurality of individual microleakage determination devices and there is a leak in the microleakage determination devices, it can be determined that a leak has occurred in the gas flow path instead of the individual gas flow paths. . As described above, from the result of the leakage determination of each device, it is possible to specify the approximate leakage location and simplify the specification of the leakage location.

  The leak location specifying system of the present invention may further include a leak location specifying means for acquiring the leak results from the plurality of individual micro leak determination devices and the micro leak determination devices and specifying the leak location. preferable.

  According to this leak location identifying system, a minute flow rate is detected within a first predetermined time after a flow rate exceeding a minute flow rate (for example, a flow rate of at least 50 L / h, preferably 100 L / h or more) is detected. When detected, it is determined that the minute flow rate is not a flow rate due to minute leakage. Here, in a gas appliance (for example, a gas stove or a gas table) that accompanies a torch, first, a large flow rate flows at the time of ignition, and then a slight flow rate tends to flow by adjusting the heating power to become a torch. In this way, the flow rate of the gas appliance accompanied with a hot flash shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate is not due to minute leakage but due to hot fire. Therefore, when such a flow rate transition is observed, it is possible to improve the determination accuracy of the minute leak by determining that the minute flow rate is not due to the minute leak.

  Further, in the leak location identifying system according to the present invention, at least one of the plurality of individual micro leak judgment devices and the micro leak judgment device may control the micro flow rate within a second predetermined time after the micro flow rate is detected. When an excess flow rate is detected and then the flow rate returns to a very small flow rate, it is preferable to determine that the very small flow rate is not a flow rate due to a slight leakage.

  According to this leak location identifying system, a flow rate exceeding the micro flow rate (for example, a flow rate of at least 50 L / h, preferably 100 L / h or more) within the second predetermined time after the micro flow rate is detected. When the flow rate is detected and then returned to a very small flow rate, it is determined that the very small flow rate is a flow rate due to pilot ignition. Here, in the gas appliance with pilot ignition, first, a small flow rate flows due to pilot ignition, and then a large flow rate tends to flow due to ignition of the main body appliance. In addition, when the use of the appliance ends, the main appliance tends to return to the minute flow rate again by shifting from the ignition state to the fire extinguishing state. Thus, the flow rate of the gas appliance with pilot ignition shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate is not due to minute leakage but due to pilot ignition. Therefore, when such a flow rate transition is observed, it is possible to improve the determination accuracy of the minute leak by determining that the minute flow rate is not due to the minute leak.

  The leak location identifying system of the present invention further includes a gas appliance determining means for determining a used gas appliance, and the at least one of the plurality of individual micro leak determining devices and the micro leak determining device includes the above When the gas appliance determination means determines that a gas appliance with pilot ignition has been used and / or when it has been determined that a gas appliance with flash fire has been used, the generated small flow rate is due to a slight leak. It is preferable to judge that it is not a flow rate.

  According to this leak location identifying system, it occurred when it was determined that a gas appliance with pilot ignition was used and / or when it was determined that a gas appliance with flash fire was used. Judge that the minute flow rate is not due to minute leakage. For this reason, when it is judged that the use of a gas appliance accompanied by pilot ignition or flashing is determined, the possibility that a slight leakage has occurred can be denied. Therefore, it is possible to further improve the accuracy of determining a minute leak.

  Further, in the leak location identifying system according to the present invention, the gas appliance determination means determines the gas appliance used based on a waveform measured during a minute time from a change of at least one of the flow rate and pressure more than a predetermined value. It is preferable to judge.

Further, the leak location specifying method of the present invention is a leak location specifying method for specifying a location where a micro leak has occurred in a housing facility that supplies fuel gas from a gas supply source to a plurality of houses, and the fuel gas from the gas supply source A micro leak judgment step for judging a micro leak in a gas flow path for supplying gas to a plurality of houses, and a micro leak in each of a plurality of individual gas flow paths for supplying the fuel gas flowing through the gas flow path to a plurality of houses And at least one of the plurality of individual microleakage determination steps and the microleakage determination step, after a flow rate exceeding the microflow rate is detected. When the minute flow rate is detected within one predetermined time, it is determined that the minute flow rate is not a flow rate due to minute leakage .

According to this leak location specifying method, since it includes a micro leak judgment step for judging micro leak in the gas flow path and a plurality of individual micro leak judgment steps for judging micro leak in each individual gas flow path, for example, a plurality of When a leak is determined in any one of the individual minute leak determination steps, it can be determined that a leak has occurred in the individual gas flow path of the house. In particular, when it is determined that there is no leakage in a plurality of individual micro leak determination processes, and it is determined that there is a leak in the micro leak determination process, it can be determined that there is a leak in the gas flow path instead of the individual gas flow paths. . As described above, from the result of the leakage determination in each step, it is possible to specify a general leakage location and simplify the specification of the leakage location. Furthermore, if a minute flow rate is detected within the first predetermined time after a flow rate exceeding the minute flow rate (for example, a flow rate of at least 50 L / h, preferably a flow rate of 100 L / h or more) is detected, Judge that the flow rate is not due to minute leakage. Here, in a gas appliance (for example, a gas stove or a gas table) that accompanies a torch, first, a large flow rate flows at the time of ignition, and then a slight flow rate tends to flow by adjusting the heating power to become a torch. In this way, the flow rate of the gas appliance accompanied with a hot flash shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate is not due to minute leakage but due to hot fire. Therefore, when such a flow rate transition is observed, it is possible to improve the determination accuracy of the minute leak by determining that the minute flow rate is not due to the minute leak.

  According to this leak location specifying method, since it includes a micro leak judgment device that judges micro leaks in a gas flow path and a plurality of individual micro leak judgment devices that judge micro leaks in each individual gas flow path, for example, a plurality of When leakage is determined by any one of the individual minute leakage determination devices, it can be determined that leakage has occurred in the individual gas flow path of the house. In particular, when it is determined that there are no leaks in a plurality of individual microleakage determination devices and there is a leak in the microleakage determination devices, it can be determined that a leak has occurred in the gas flow path instead of the individual gas flow paths. . As described above, from the result of the leakage determination of each device, it is possible to specify the approximate leakage location and simplify the specification of the leakage location.

  ADVANTAGE OF THE INVENTION According to this invention, the leak location identification system and leak location specification method which can aim at simplification about the specification of a leak location can be provided.

1 is a configuration diagram of a gas supply system including a leak location identifying system according to an embodiment of the present invention. It is a block diagram which shows the detail of the micro leak judgment apparatus shown in FIG. It is a block diagram which shows the detail of the gas meter shown in FIG. It is a figure which shows an example of the flow volume waveform of the gas appliance with a pilot ignition function. It is a figure which shows an example of the flow volume waveform of the gas appliance with a hot fire. It is a figure which shows the outline of the gas leak vibration waveform produced | generated by the production | generation part shown in FIG.2 and FIG.3. It is a figure which shows the pressure change at the time of gas leak. It is a graph which shows continuous NCC at the time of gas leak. It is a graph which shows the pressure change at the time of gas appliance use start, Comprising: (a) shows the pressure change at the time of gas table use start, (b) shows the pressure change at the time of gas BF bath use start, (c) Indicates the pressure change at the start of use of the water heater. It is a graph which shows the continuous NCC calculated by the gas leak / gas appliance judgment part shown in FIG.2 and FIG.3, Comprising: (a) shows the continuous NCC at the time of a gas table use start, (b) is a gas BF bath. The continuous NCC at the start of use of the kettle is shown, and (c) shows the continuous NCC at the start of use of the water heater. It is a graph which shows the spectrum data obtained by Fourier-transforming the pressure waveform when a gas leak generate | occur | produces. It is a graph which shows the spectrum data obtained by Fourier-transforming the pressure waveform when a gas table is used. It is a graph which shows the spectrum data obtained by Fourier-transforming the pressure waveform when a gas BF bath is used. It is a flowchart which shows an example of the microleakage determination method which concerns on this embodiment, Comprising: The process for determining use of the gas appliance with pilot ignition and microleakage is shown. It is a flowchart which shows an example of the microleakage determination method which concerns on this embodiment, Comprising: The process for judging use of the gas appliance accompanied with a torch and microleakage is shown. It is a basic flowchart of gas leak / gas appliance judgment. FIG. 17 is a first flowchart showing details of the gas leak / gas appliance determination shown in step S24 of FIG. 16 and shows the first method. It is a 2nd flowchart which shows the detail of the gas leak / gas appliance judgment shown to FIG.16 S24, Comprising: The 2nd method is shown.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a gas supply system 1 including a leak location identifying system according to an embodiment of the present invention. In the following, the gas supply system 1 that supplies LP gas as fuel gas will be described as an example. However, the present invention is not limited to this, and the gas supply system 1 may supply city gas.

  The gas supply system 1 is a housing facility that supplies fuel gas from a gas cylinder (gas supply source) 110 to a plurality of houses 2. The gas supply system 1 includes a supply-side facility 100, a house-side facility 200, and a gas management center 300. The supply-side facility 100 includes a gas cylinder 110, a gas flow path 120, first to third pressure regulators 130 to 150, and a minute leak determination device 160.

  The gas flow path 120 is a gas pipe that supplies fuel gas from a gas cylinder to the plurality of houses 2 side. The gas flow path 120 includes a main flow path 121 that continues from the gas cylinder to the plurality of houses 2, and a bypass flow path 122 that is connected to the main flow path 121 at both ends and bypasses the main flow path 122.

  The 1st-3rd pressure regulators 130-150 are provided on the gas flow path 120, and adjust a downstream gas pressure with two states, a blockage state and an open state. Among these, the 1st pressure regulator 130 is provided in the gas cylinder 110 side, and the 3rd pressure regulator 150 is provided in the bypass flow path 122 of the downstream of the 1st pressure regulator 130. FIG. The second pressure regulator 140 is provided on the downstream side of the first pressure regulator 130 and in a portion of the main channel 121 that is bypassed by the bypass channel 122.

  The micro-leakage determination device 160 is provided on the bypass flow channel 122 in the gas flow channel 120 and determines a micro-leakage in the gas flow channel 120. The minute leak determination device 160 has a function of determining whether the minute flow rate is due to minute leakage or the use of a gas appliance. For this reason, the minute leak determination device 160 determines whether the minute flow rate is a flow rate due to the use of the gas appliance when it detects a minute flow rate, and determines that the minute flow rate is not a flow rate due to the use of the gas appliance. It is judged that.

  The house-side facility 200 includes a plurality of individual gas passages 210, a plurality of valves 220, a plurality of gas meters (a plurality of individual microleakage determination devices) 230, and a plurality of gas appliances 240. The plurality of individual gas passages 210 supplies the fuel gas flowing through the gas passage 120 to the plurality of houses 2. The plurality of individual gas passages 210 are branched from the gas passage 120 to supply fuel gas to the plurality of houses 2 respectively.

  The valve 220 is provided at an upstream portion of each individual gas flow path 210. By opening and closing the valve 220, a resident of each house 2 can draw fuel gas into the home.

  The gas meter 230 measures the flow rate of the fuel gas and displays the integrated flow rate. In addition, the gas meter 230 is provided on each of the plurality of individual gas flow paths 210 and has a function of determining minute leakage in each individual gas flow path 210. Further, in the same manner as the minute leak determination device 160, when the plurality of gas meters 230 detect a minute flow rate, it is determined whether the minute flow rate is a flow rate due to the use of the gas appliance 240, and is not a flow rate due to the use of the gas appliance 240. In this case, it is determined that the minute flow rate is a flow rate due to minute leakage.

  The plurality of gas appliances 240 are a gas stove, a fan heater, a water heater, a floor heating, a gas table, a gas BF bath, and the like. Here, the gas table is a gas appliance 240 with a torch. Toro-fire is the minimum area of fire with low momentum, and sometimes referred to as lukewarm or simmering fire. Specifically, in the case of table stoves, it refers to the amount of fire when boiling boiled beans or porridge for a long time. In addition, the gas appliance 240 accompanied with a torch is not limited to a gas table, and there are other types such as a gas stove and a table stove.

  The gas BF bath is a gas appliance 240 having a pilot burner, and the main appliance is started to be used by igniting the main burner after ignition of the pilot burner. The gas appliance 240 having a pilot burner is not limited to a gas BF bath, and there are various types such as a CF bath and an old small water heater.

  In the example shown in FIG. 1, the gas meter 230 is cited as an example of the individual microleakage determination device, but the individual microleakage determination device is not limited to the gas meter 230. Similarly, the microleakage determination device 160 may be a gas meter, or may be a device that determines only microleakage.

  The gas management center 300 communicates with the gas meter 230 to issue a control signal for closing the shutoff valve in the gas meter 230 or to request a gas company to be dispatched when a gas leak (including a slight leak) occurs in the house 2. It is something to do. Further, the gas management center 300 can also communicate with the minute leak determination device 160.

  In such a gas supply system 1, when a signal indicating that there is a minute leak is received from at least one of the minute leak determination device 160 and the plurality of gas meters 230, a request for dispatch of a gas company is made. As a result, the gas company will inspect which part of the gas supply system 1 has a slight leak. At this time, in this embodiment, for example, when leakage is determined in any one of the plurality of gas meters 230, it can be determined that leakage has occurred in the individual gas flow path 230 of the house 2. Further, when it is determined that there is no leakage in the plurality of gas meters 230 and it is determined that there is a leakage in the minute leakage determination device 160, it can be determined that there is a leakage in the gas flow path 120 instead of the individual gas flow path 210. . As described above, in the present embodiment, it is possible to specify an approximate leak location from the result of the leak determination of each device 160, 230, and it is possible to simplify the specification of the leak location.

  In this case, the gas flow path 120, the micro leak determination device 160, the plurality of individual gas flow paths 210, and the plurality of gas meters 230 function as a leak location specifying system that specifies locations where micro leaks are generated.

  Furthermore, since the gas management center 300 is provided in the present embodiment, when the determination result of the minute leak from the plurality of gas meters 230 and the minute leak judgment device 160 is acquired, the leak point is specified in the gas management center 300. Also good. This is because it is possible to specify a general leak location without requiring a gas operator's confirmation work, and to further simplify the specification of the leak location.

  In this case, the gas management center 300 functions as a leakage location specifying means, and the gas flow path 120, the minute leakage determination device 160, the plurality of individual gas flow paths 210, the plurality of gas meters 230, and the gas management center 300 are minute. It will function as a leak location identifying system that identifies locations where leaks have occurred.

  FIG. 2 is a block diagram showing details of the microleakage determination device 160 shown in FIG. As shown in FIG. 2, the minute leak determination device 160 includes a flow sensor 161, a pressure sensor 162, a determination unit 163, a trigger signal generation unit 164, a generation unit 165, a similarity transition storage unit 166, and a flow rate. A value storage unit 167 and a spectrum data storage unit 168 are provided.

  In addition, the determination unit 163 includes a pilot ignition determination unit 163a, a flash fire determination unit 163b, a minute leak determination unit 163c, a gas leak / gas appliance determination unit (gas appliance determination means) 163d, and a sampling time adjustment unit 163e. I have.

  FIG. 3 is a block diagram showing details of the gas meter 230 shown in FIG. As shown in FIG. 3, the gas meter 230 includes a flow rate sensor 231, a pressure sensor 232, a determination unit 233, a trigger signal generation unit 234, a generation unit 235, a similarity transition storage unit 236, and a spectrum data storage unit. 237 and a flow rate storage unit 238.

  In addition, the determination unit 233 includes a pilot ignition determination unit 233a, a hot flash determination unit 233b, a minute leak determination unit 233c, a gas leak / gas appliance determination unit (gas appliance determination means) 233d, and a sampling time adjustment unit 233e. I have.

  Here, the elements having the same names shown in FIG. 2 and FIG. 3 are basically the same in configuration and function, and both will be described collectively.

  The flow path sensors 161 and 231 output a measurement value signal corresponding to the gas flow rate in the flow path of the microleakage determination device 160 or the gas meter 230, and are constituted by an ultrasonic sensor, a flow sensor, or the like. The pressure sensors 162 and 232 output a measurement value signal corresponding to the gas pressure in the flow path of the microleakage determination device 160 or the gas meter 230, and are constituted by sensors such as a piezoresistive type or a capacitance type. Is done.

  The determination units 163 and 233 perform various determinations in the microleakage determination device 160 and the gas meter 230. For example, based on the signals from the flow path sensors 161 and 231 and the signals from the pressure sensors 162 and 232, the gas The leak and the gas appliance 240 to be used are determined.

  The pilot ignition determination units 163a and 233a determine the flow rate due to pilot ignition. Specifically, pilot ignition determination units 163a and 233a determine the flow rate due to pilot ignition based on the flow rate transition shown in FIG.

  FIG. 4 is a diagram illustrating an example of a flow waveform of the gas appliance 240 with a pilot ignition function. As shown in FIG. 4, first, it is assumed that the gas appliance 240 with a pilot ignition function is started to be used at time t41. At this time, only the pilot burner is ignited, and the flow rate value is 10 to 20 L / h. That is, a minute flow rate F41 flows.

  After that, it is assumed that the main burner is ignited at time t42 and the main device is started to be used. Thereby, the large flow F42 flows out. The flow rate value at this time is at least 50 L / h, and in many cases is 100 L / h or more. In most cases, it is within several tens of seconds (an example of the first predetermined time) from when the user performs pilot ignition until the use of the main device is started.

  Next, it is assumed that the use of the main body instrument is finished at time t43. Thereby, it transfers to the fire extinguishing state from the ignition state of a main body instrument, and the very small flow F41 of 10-20 L / h will flow. Thereafter, the pilot burner is extinguished, and the flow rate value is 0 L / h.

  Thus, when using the gas appliance 240 with a pilot ignition function, the flow rate flows in the order of the minute flow rate F41, the large flow rate F42, and the minute flow rate F41. In addition, the first flow of the minute flow rate F41 (time t41) to the flow of the large flow rate F42 (time t42) is within the first predetermined time.

  In the description of FIG. 4, the flow rate values of the first micro flow rate F41 and the micro flow rate F41 after the return are the same, but they may not be the same. That is, both flow rates F41 should just be in the range of a specific value.

  Again referring to FIG. 2 and FIG. The pilot ignition determination units 163a and 233a determine the flow rate due to pilot ignition by capturing the flow rate transition as shown in FIG. That is, the pilot ignition determination units 163a and 233a detect the minute flow rate F41 when the flow rate F42 exceeding the minute flow rate F41 is detected within the first predetermined time after the minute flow rate F41 is detected, and then the flow rate returns to the minute flow rate F41. Is determined to be the flow rate due to pilot ignition.

  The hot water judgment units 163b and 233b judge the flow rate of hot water. Specifically, the hot fire determination units 163b and 233b determine the flow rate of hot fire based on the flow rate transition shown in FIG.

  FIG. 5 is a diagram illustrating an example of a flow rate waveform of the gas appliance 240 accompanied by a fire. As shown in FIG. 5, first, it is assumed that the gas appliance 240 accompanied by a torch is started to be used at time t51. At this time, since the ignition is initially performed, a flow rate exceeding a minute flow rate flows, and the flow rate value indicates F52.

  Thereafter, the user gradually rotates the rotary knob on the gas table so that the user can turn off the heating power of the gas appliance 240. Thereby, the flow rate gradually decreases from time t52 to time t53, and a minute flow rate F51 is shown at time t53. In most cases, the time from the ignition at time t51 to the melting at time t53 is within a few tens of minutes (an example of the second predetermined time).

  Next, from time t53 to time t54, stew by boiling water is performed, and then use of the gas appliance 240 accompanied by boiling is finished. Thereby, the gas appliance 240 shifts from the melted fire state to the fire extinguishing state, and the flow rate value becomes 0 L / h.

  As described above, when the gas appliance 240 accompanied by a fire is used, the minute flow rate F51 flows after the flow rate F52 exceeding the minute flow rate F51. Moreover, the time from the flow of the flow rate F52 (time t51) to the minute flow rate F51 (time t52) is within the second predetermined time.

  Again referring to FIG. 2 and FIG. The hot water judgment units 163b and 233b determine the flow rate of hot water by capturing the flow rate transition as shown in FIG. That is, when the low flow rate F51 is detected within the second predetermined time after the flow rate F52 exceeding the small flow rate F51 is detected, the flash fire determination units 163b and 233b determine that the small flow rate F51 is a flow rate due to the fire.

  The minute leakage determination units 163c and 233c determine whether the minute flow rates F41 and F51 are flow rates due to minute leakage. The minute leakage determination units 163c and 233c determine that the minute flow rate F41 is not a flow rate due to minute leakage when the pilot ignition determination units 163a and 233a determine the flow rate due to pilot ignition. That is, when the flow rate transition as shown in FIG. 4 is observed and it can be inferred that the gas appliance 240 with the pilot ignition function is used, the micro leak judgment unit 163c, 233c is caused by the micro leak. It will be judged that it is not.

  Similarly, the minute leakage determination units 163c and 233c determine that the minute flow rate F51 is not a flow rate due to minute leakage when the flow rate due to the fire is determined by the melting fire determination units 163b and 233b. That is, when the flow rate transition as shown in FIG. 5 is observed and it can be inferred that the gas appliance 240 accompanied by hot fire is used, the micro leak determination unit 163c, 233c does not cause the micro flow rate F51 due to micro leak. It will be judged.

  The gas leak / gas appliance determination units 163d and 233d determine whether or not a gas leak has occurred and determine the gas appliance 240 used. In particular, the gas leak / gas appliance determination units 163d and 233d determine whether or not the gas appliance 240 accompanied by pilot ignition is used, and determine whether or not the gas appliance 240 accompanied by flash fire is used. As a result of this determination, the micro-leakage determination units 163c and 233c discriminate between the micro-leakage, the flow rate due to pilot ignition, and the flow rate due to flash fire.

  In detail, the gas leak / gas appliance determination units 163d and 233d cooperate with the generation units 165 and 235 and the similarity transition storage units 166 and 236 to determine gas leaks (excluding minute leaks), and gas leaks are generated. If it can be determined that the gas appliance 240 is not used, the gas appliance 240 in use is determined (first method). Further, when the gas leakage / gas appliance determination unit 163d, 233d determines gas leakage (excluding minute leakage) in cooperation with the spectrum data storage units 167, 237, and can determine that no gas leakage has occurred. Next, the gas appliance 240 in use is determined (second method). In any method, the gas leak / gas appliance determination unit 163d, 233d is based on a waveform measured during a minute time (up to 2 seconds) from a change of at least one of the gas flow rate and the gas pressure exceeding a predetermined value. Thus, the gas leakage and the gas appliance 240 to be used are determined.

  First, the first method will be described. The generation units 165 and 235 generate a gas leak vibration waveform when it is assumed that a gas leak has occurred. The gas leak / gas appliance determination units 163d and 233d determine the gas leak based on the gas leak vibration waveform generated by the generation units 165 and 235.

  FIG. 6 is a diagram showing an outline of a gas leakage vibration waveform generated by the generation units 165 and 235 shown in FIGS. As illustrated in FIG. 6, the generation units 165 and 235 generate a gas leak vibration waveform that vibrates while the pressure decreases with time. This gas leakage vibration waveform is a waveform generated based on a second-order delay step response equation including the frequency, gain, and damping ratio of the damped vibration. Here, the present inventors have found that vibration occurs in the measured values of the pressure and the flow rate in a minute time (maximum 2 seconds) immediately after the occurrence of gas leakage. Therefore, the generation units 165 and 235 generate a gas leakage vibration waveform based on a second-order delay step response equation as information necessary for determining gas leakage, and the gas leakage / gas appliance determination units 163d and 233d The occurrence of gas leakage is determined based on the gas leakage vibration waveform generated in the generation units 165 and 235.

  As shown in FIG. 6, the generation units 165 and 235 generate a gas leakage vibration waveform of pressure, but not limited to this, generate a gas leakage vibration waveform that oscillates as the flow rate increases with time. May be. Further, it is desirable that this waveform is also determined based on a second-order delay step response equation.

Again referring to FIG. 2 and FIG. The gas leak / gas appliance determination units 163d and 233d are similar in degree to the input signal waveforms from the sensors 161, 162, 231, and 232 and the gas leak vibration waveforms generated in the generation units 165 and 235. Calculate the transition. The similarity transition refers to continuous normal cross correlation (NCC) in the present embodiment. More specifically, the similarity _RNCC is obtained by the following equation (1). Gas leakage / gas appliance determination unit 163d, 233 d, by performing the calculation of the similarity _{R NCC} according to the equation (1) continuously, the similarity transition (hereinafter, referred to as continuous NCC) Request.

  Then, the gas leak / gas appliance determination units 163d and 233d determine the occurrence of gas leak based on the calculated similarity transition. In particular, in this embodiment, as an example, when the representative value of the similarity transition calculated by the gas leak / gas appliance determination unit 163d, 233d is equal to or greater than a threshold value, it is determined that a gas leak has occurred. . Here, the representative value may be the total degree of similarity or the average value of a specific period of the whole degree of similarity, or the degree of similarity at a specific time after a change in pressure or flow rate occurs. Alternatively, other values may be used.

  Next, a pressure change at the time of gas leakage will be described with reference to FIG. FIG. 7 is a diagram showing a pressure change at the time of gas leakage. As shown in FIG. 7, when a gas leak occurs, a waveform that vibrates while the pressure decreases is shown. This waveform has a high correlation with the gas leakage vibration waveform generated by the generation units 165 and 235 as shown in FIG. For this reason, the representative value of the similarity transition shows a high value, and the gas leak / gas appliance determination units 163d and 233d determine that a gas leak has occurred.

  FIG. 8 is a graph showing continuous NCC at the time of gas leakage. In FIG. 8, the solid line and the broken line indicate continuous NCC when conditions such as a difference in piping state, a difference in gas leak location, and a difference in gas leak flow rate in each home are different.

  As shown in FIG. 8, the continuous NCC immediately after the occurrence of a pressure change at the time of gas leakage (near time 0 seconds) shows a value of about “0.7” to “0.8”. However, the continuous NCC shows a value of “0.9” or more after time 0.025 seconds. Therefore, the gas leak / gas appliance determination unit 163d, 233d determines that the gas leak / gas appliance determination unit 163d, 233d has the gas transition / gas appliance determination unit 163d, 233d, and the gas leak / gas appliance determination unit 163d, 233d Judge that a leak has occurred.

  On the other hand, as shown in FIG. 9, when the gas appliance is used, a vibration waveform different from that at the time of gas leakage is shown. FIG. 9 is a graph showing the pressure change at the start of gas appliance use, where (a) shows the pressure change at the start of gas table use, and (b) shows the pressure change at the start of gas BF bath use. (C) has shown the pressure change at the time of a water heater start use.

  As shown in FIG. 9A, a pressure waveform that smoothly vibrates at a pressure of about 2.9 kPa is obtained at the start of use of the gas table. Moreover, as shown in FIG.9 (b), the pressure waveform which vibrates strongly 0.1 kPa on the basis of a pressure of 2.93 kPa is obtained at the end of use of the gas BF bath. Further, as shown in FIG. 9 (c), a pressure waveform is obtained that shows a slightly rougher vibration than the small water heater on the basis of the pressure of 2.93 kPa at the end of use of the water heater.

  FIG. 10 is a graph showing continuous NCC calculated by the gas leakage / gas appliance determination units 163d and 233d shown in FIGS. 2 and 3, wherein (a) shows the continuous NCC at the start of use of the gas table, (B) shows the continuous NCC at the start of use of the gas BF bath, and (c) shows the continuous NCC at the start of use of the water heater.

  When the use of the gas table is started, the vibration waveform of FIG. 9A is obtained, and the continuous NCC calculated by the gas leak / gas appliance determination units 163d and 233d is as shown in FIG. That is, the continuous NCC initially shows about “1.0”, then falls below “0.2”, and returns to “0.95” in about 0.04 seconds. The continuous NCC becomes about “0.5” in about 0.1 second, and then slowly rises to near “0.65”.

  When the use of the small water heater is started, the vibration waveform of FIG. 9B is obtained, and the continuous NCC calculated by the gas leak / gas appliance determination units 163d and 233d is as shown in FIG. become. That is, the continuous NCC initially shows about “1.0”, then falls below “0.2”, and returns to “0.9” in about 0.04 seconds. Then, the continuous NCC again decreases to about “0.4”, and then slowly increases to near “0.7”.

  When the use of the water heater starts, the vibration waveform of FIG. 9C is obtained, and the continuous NCC calculated by the gas leak / gas appliance determination units 163d and 233d is as shown in FIG. 10C. . That is, the continuous NCC initially shows a value of “0.8”, then falls below “0.2” and returns to “0.7” in about 0.02 seconds. Then, the continuous NCC decreases to about “0.6” and then returns to about “0.7”. After that, the continuous NCC again decreases to about “0.5”, and then becomes less than “0.6” in about 0.1 second. Thereafter, the continuous NCC rises slowly to near “0.65”.

  Thus, at the beginning of use of the gas appliance 240, the continuous NCC does not show "0.9" or more for most of the period. For this reason, the gas leak / gas appliance determination units 163d and 233d determine that the gas appliance 240 has been used when the representative value of the continuous NCC is not equal to or greater than the threshold value.

  The continuous NCC is different for each gas appliance 240. Therefore, the gas leak / gas appliance determination unit 163d, 233d determines the gas appliance 240 used from such a continuous NCC pattern. Specifically, the continuous NCC pattern of each gas appliance 240 is stored in the similarity transition storage units 166 and 236 shown in FIGS. 2 and 3. That is, the similarity transition storage units 166 and 236 store the continuous NCC pattern as shown in FIG. 10A for the gas table, and the continuous NCC as shown in FIG. 10B for the small water heater. The continuous NCC pattern as shown in FIG. 10C is stored for the water heater. The gas leakage / gas appliance determination units 163d and 233d use the gas appliance 240 indicated by the continuous NCC data closest to the calculated continuous NCC among the continuous NCC data stored in the similarity transition storage units 166 and 236. Judge that it was done. In particular, the gas leak / gas appliance determination unit 163d, 233d determines that the gas appliance 240 accompanied by pilot ignition is used when the gas appliance 240 indicated by the nearest continuous NCC data is a gas BF bath. Furthermore, when the gas appliance 240 indicated by the nearest continuous NCC data is a gas table, the gas leak / gas appliance determination unit 163d, 233d determines that the gas appliance 240 accompanied by a fire is used.

  Although FIGS. 7 to 10 show the vibration waveform of pressure and the continuous NCC based on the vibration waveform of pressure, the gas leak determination can be performed in the same manner for the flow rate. In the following description, gas leak judgment based on the vibration waveform of pressure will be described, but it goes without saying that the same applies to the flow rate.

Next, details of the gas leakage vibration waveform will be described. If it demonstrates in detail, the production | generation parts 165 and 235 will produce | generate a gas leak vibration waveform as follows. First, the generation units 165 and 235 store the following expression (2).

Here, y (t) indicates the amount of change in pressure, K indicates the gain, ω _d indicates the frequency of the damped vibration, and ζ indicates the damping ratio. In particular, the gain K, the damping vibration frequency ω _d , and the damping ratio ζ are obtained from the waveforms actually measured by the pressure sensor 42. Next, these calculation methods will be described with reference to FIG.

The generation units 165 and 235 calculate the frequency ω _{d of the} damped vibration from the following equation (3).

Here, Tp is an overshoot time, and as shown in FIG. 7, refers to the time from the occurrence of a pressure change to the first extreme value V1 (minimum value V1). When the first extreme value V1 is confirmed from the input signal, the generation units 165 and 235 obtain the overshoot time Tp, and calculate the frequency ω _{d of the} damped vibration from Expression (3).

The frequency ω _{d of the} damped vibration is not limited to that obtained from the equation (3), but the second extreme value M (maximum point M) or the third extreme value V2 (minimum point) from the time of occurrence of the pressure change. It may be calculated based on V2).

Next, the generation units 165 and 235 calculate the gain K from the following equation (4).

  Because of such an expression, the generation units 165 and 235 calculate the gain K from the expression (4) when the extreme values V1, M, and V2 are confirmed from the input signal.

  As is apparent from FIG. 7, the gain K can also be obtained from the difference between the pressure value before the pressure change occurs and the pressure value after the pressure change occurs. Therefore, the generation units 165 and 235 may obtain the gain K from the difference when a pressure change occurs and the pressure value becomes a substantially constant value (time 0.4 seconds in FIG. 7). Furthermore, the generation units 165 and 235 may calculate the gain K in consideration of the fourth and subsequent extreme values from the time when the pressure change occurs.

Next, the generation units 165 and 235 calculate the damping ratio ζ from the following equation (5).

  Here, δ is a logarithmic decay rate, and m is the number of periods. In the case of Expression (5), the number of periods m is “0.5”.

  Due to such an expression, the generation units 165 and 235 calculate the attenuation ratio ζ from the expression (5) when the extreme values V1 and M are confirmed from the input signal.

As described above, the generating units 165 and 235 calculate the gain K, the frequency ω _{d of the} damped vibration, and the damping ratio ζ, and obtain the vibration waveform expression from Expression (2). Then, the gas leak / gas appliance determination units 163d and 233d obtain a continuous NCC according to the equation (1) from the obtained equation and the input pressure waveform.

Here, the generation units 165 and 235 may calculate the frequency ω _{d of the} damping vibration and the damping ratio ζ. That is, the vibration waveform shown in FIG. 7 tends to depend on the flow rate at the time of gas leakage. For this reason, the generation units 165 and 235 store in advance an expression including only the flow rate value as a variable, and substitute the flow rate value measured by the flow rate sensors 161 and 231 into this expression to obtain the frequency ω _{d of the} damped vibration, and The damping ratio ζ may be obtained.

Specifically, the generation units 165 and 235 obtain the damping vibration frequency ω _d and the damping ratio ζ from the following equation (6).

Here, L is a flow rate value, and a ₁ , a ₂ , b ₁ , and b ₂ are constants. In this way, the calculation amount may be reduced by obtaining from Expression (6), and the calculation process may be simplified. There is a certain correlation between the flow rate and the pressure. For this reason, instead of the equation (6), an equation including only the pressure value as a variable may be stored, and the frequency ω _{d of the} damping vibration and the damping ratio ζ may be obtained from this equation.

  Furthermore, in this case, it is desirable that the generation units 165 and 235 also obtain the gain K from the difference between the pressure value before the pressure change occurrence and the pressure value after the pressure change occurrence without calculating the gain K from the equation (4). This is because the amount of calculation can be further reduced.

  Next, the gas leak and determination of the gas appliance 240 to be used according to the second method will be described in detail. The spectrum data storage units 167 and 237 shown in FIG. 2 are obtained by spectral data obtained by Fourier transforming a waveform predicted to be obtained in a minute time immediately after the occurrence of gas leakage, and in a minute time immediately after the use of each gas appliance 240. The spectrum data obtained by Fourier transforming the expected waveform is stored.

  FIG. 11 is a graph showing spectrum data obtained by Fourier transforming a pressure waveform when a gas leak occurs, and FIG. 12 is a spectrum obtained by Fourier transforming the pressure waveform when a gas table is used. It is a graph which shows data. FIG. 13 is a graph showing spectral data obtained by Fourier transforming a pressure waveform when a gas BF bath is used.

  As shown in FIG. 11, when a gas leak occurs, the obtained pressure waveform contains almost no frequency component of 20 Hz or more. In addition, as shown in FIG. 12, when a gas table is used, the obtained pressure waveform contains almost no frequency component of 20 Hz or more, but tends to show a large amplitude in the frequency component around 10 Hz. . Moreover, as shown in FIG. 13, when a gas BF bath is used, the obtained pressure waveform tends to exhibit a slightly large amplitude in a frequency component of 70 Hz to 100 Hz. In addition, the peak which exists in 60-Hz vicinity in FIGS. 11-13 is the noise by a commercial power source.

  Reference is again made to FIG. The spectrum data storage units 167 and 237 store spectrum data as shown in FIGS. Then, the gas leak / gas appliance determination units 163d and 233d determine the gas leak and the gas appliance 240 to be used based on the spectrum data. Specifically, the gas leak / gas appliance determination units 163d and 233d obtain a pressure waveform in a minute time, and then perform Fourier transform on the waveform to generate spectrum data. After generating the spectrum data, the gas leak / gas appliance determination units 163d and 233d read the stored contents of the spectrum data storage units 167 and 237, and specify the stored spectrum data that is closest to the generated spectrum data. . If the identified spectral data indicates a gas leak, the gas leak / gas appliance determination unit 163d, 233d determines that a gas leak has occurred. If the specified spectrum data is not a gas leak, the gas leak / gas appliance determination unit 163d, 233d determines that the gas appliance 240 indicated by the specified spectrum data has been used. In particular, when the gas appliance 240 indicated by the specified spectrum data is a gas table, the gas leak / gas appliance determination units 163d and 233d determine that the gas appliance 240 accompanied by a flash fire has been used.

  Again referring to FIG. 2 and FIG. The trigger signal generators 164 and 234 detect a change in gas flow rate or gas pressure and output a trigger signal. For example, the trigger signal generators 164 and 234 are configured to include a differentiation circuit, and detect a change greater than a predetermined value by the differentiation circuit.

  The trigger signal is input to each of the sensors 161, 162, 231, 232 and the sampling time adjustment units 163e, 233e. When the trigger signal is input, the sampling time adjustment units 163e and 233e shorten the sampling time from a predetermined normal sampling time (for example, 2 seconds for the flow rate and 10 seconds for the pressure). At this time, the determination units 163 and 233 shorten the sampling time by a minute time. Thereby, the determination parts 163 and 233 measure the waveform in minute time in detail. That is, high-speed sampling is performed in order to make the judgment by the gas leak / gas appliance judgment units 163d and 233d accurate. In addition, when a trigger signal is input, each of the sensors 161, 162, 231, 232 outputs a signal in accordance with high-speed sampling. In addition, the drive currents of the sensors 161, 162, 231, 232 in the normal state may be reduced, and the drive current may be increased to the normal current after the trigger signal is input.

  The sampling time adjustment units 163e and 233e make the sampling time of at least one of the gas flow rate and the gas pressure longer than the normal sampling time until a trigger signal is generated by the trigger signal generation units 164 and 234, for example, The flow rate is set to 10 seconds. Here, the case where no trigger signal is generated and the flow rate or pressure does not change more than a predetermined amount can be said to be a case where the flow rate or pressure is stable and the necessity for measurement is small. Therefore, in this embodiment, the power consumption is reduced by increasing the sampling time in such a case.

  The flow rate value storage units 168 and 238 store the flow rate value due to pilot ignition when the pilot ignition determination units 163a and 233a determine that the minute flow rate F41 is a flow rate due to pilot ignition. Therefore, after the pilot ignition flow rate value is stored in the flow rate value storage units 168 and 238, and the flow rate value within the specified range is detected, the pilot ignition determination units 163a and 233a are in the specified range. The flow rate within is determined to be the flow rate due to pilot ignition. Thus, pilot ignition can be quickly determined without observing the flow rate transition as shown in FIG.

  The flow rate value storage units 168 and 238 store the flow rate value due to hot water when the low flow rate F51 is determined as the flow rate due to hot water by the hot water judgment units 163b and 233b. For this reason, when the flow rate value and the flow rate value within the specified range are detected after the flow rate value of the hot water is stored in the flow rate value storage units 168 and 238, the hot water determination units 163b and 233b are within the specified range. The flow rate is judged to be the flow rate due to fire. As a result, it is possible to quickly determine the torch without observing the flow rate transition as shown in FIG.

  Next, a microleakage determination method according to the present embodiment will be described. FIG. 14 is a flowchart showing an example of the minute leak determination method according to the present embodiment, and shows processing for determining use of the gas appliance 240 accompanied by pilot ignition and minute leak. As shown in FIG. 14, first, the determination units 163 and 233 determine whether or not there is a minute flow rate F41 based on signals from the flow rate sensors 161 and 231 (S1). When it is determined that there is no minute flow rate F41 (S1: NO), this process is repeated until it is determined that there is a minute flow rate F41.

  When it is determined that the minute flow rate F41 is present (S1: YES), the pilot ignition determination units 163a and 233a determine whether or not the flow rate value at the time of pilot ignition is stored in the flow rate value storage units 168 and 238 (S2). ). If it is determined that it is not stored (S2: NO), the process proceeds to step S4.

  When it is determined that it is stored (S2: YES), the pilot ignition determination unit 163a, 233a determines whether or not the minute flow rate F41 is within the specified range of the flow rate value stored in the flow rate value storage units 168, 238. Judgment is made (S3). If it is determined that it is within the specified range (S3: YES), the process proceeds to step S5.

  On the other hand, when it is determined that it is not within the specified range (S3: NO), the pilot ignition determination unit 163a, 233a determines whether or not there is a flow rate transition as shown in FIG. 3 (S4). When it is determined that the flow rate has changed (S4: YES), the process proceeds to step S5.

  If it is determined that there is no flow rate transition (S4: NO), the gas leak / gas appliance determination unit 163d, 233d determines whether the gas appliance 240 with a pilot function is used (S6). When it is determined that the pilot function gas appliance 240 has been used (S6: YES), the process proceeds to step S5.

  On the other hand, if it is determined that the gas appliance 240 with a pilot function is not used (S6: NO), the minute leakage determination unit 163c determines that the minute flow rate F41 is due to minute leakage (S7). Thereafter, the process shown in FIG. 14 ends.

  In step S5, the pilot ignition determination units 163a and 233a determine that the minute flow rate F41 is a flow rate due to pilot ignition (S5). Then, the pilot ignition determination units 163a and 233a determine again whether or not the flow rate values at the time of pilot ignition are stored in the flow rate value storage units 168 and 238 (S8). If it is determined that it is stored (S8: YES), the process shown in FIG. 14 ends. On the other hand, when it is determined that it is not stored (S8: NO), the flow value storage units 168 and 238 store the minute flow F1 (S9), and the process shown in FIG.

  FIG. 15 is a flowchart showing an example of a microleakage determination method according to the present embodiment, and shows a process for determining the use of the gas appliance 240 accompanied by a hot fire and a microleakage. As shown in FIG. 15, first, the determination units 163 and 233 determine whether or not there is a minute flow rate F51 based on signals from the flow rate sensors 161 and 231 (S11). When it is determined that there is no minute flow rate F51 (S11: NO), this process is repeated until it is determined that there is a minute flow rate F51.

  When it is determined that there is a minute flow rate F51 (S11: YES), the hot water determination units 163b and 233b determine whether or not the flow rate value at the time of hot fire is stored in the flow value storage units 168 and 238 (S12). If it is determined that it is not stored (S12: NO), the process proceeds to step S14.

  When it is determined that it is stored (S12: YES), the flash fire determination unit 163b, 233b determines whether the minute flow rate F51 is within the specified range of the flow rate value stored in the flow rate value storage units 168, 238. (S13). If it is determined that it is within the specified range (S13: YES), the process proceeds to step S15.

  On the other hand, when it is determined that it is not within the specified range (S13: NO), the flash fire determination unit 163b, 233b determines whether or not there is a flow rate transition as shown in FIG. 3 (S14). When it is determined that the flow rate has changed (S14: YES), the process proceeds to step S15.

  When it is determined that there is no flow rate transition (S14: NO), the gas leak / gas appliance determination unit 163d, 233d determines whether or not the gas appliance 240 accompanied by hot water is used (S16). When it is determined that the gas appliance 240 with hot water is used (S16: YES), the process proceeds to step S15.

  On the other hand, when it is determined that the gas appliance 240 with torch is not used (S16: NO), the minute leakage determination units 163c and 233c determine that the minute flow rate F51 is due to the minute leakage (S17). Thereafter, the process shown in FIG. 15 ends.

  In step S15, the hot fire determining units 163b and 233b determine that the minute flow rate F51 is a flow rate of hot fire (S15). Then, the hot fire determining units 163b and 233b determine again whether or not the flow value at the time of hot fire is stored in the flow value storage units 168 and 238 (S18). If it is determined that it is stored (S18: YES), the processing shown in FIG. 15 ends. On the other hand, when it is determined that it is not stored (S18: NO), the flow rate storage units 168 and 238 store the minute flow rate F51 (S9), and the process shown in FIG.

  It should be noted that the processing shown in steps S6 and S16, that is, whether or not the gas appliance 10 with a pilot ignition function has been used and whether or not the gas appliance 240 with a flashing fire has been used are as shown in FIGS. To be judged. At this time, in the minute leak judgment device 160 and the gas meter 230 according to the present embodiment, not only whether or not the gas appliance 240 with a pilot ignition function is used, and whether or not the gas appliance 240 accompanied by a flash fire is used, Judgment of gas leakage (excluding minute leakage) and gas appliance 240 to be used is performed.

  FIG. 16 is a basic flowchart of gas leak / gas appliance determination. First, when a gas leak or the gas appliance 240 is used, changes in the gas flow rate and the gas pressure are more than predetermined. Therefore, the determination units 163 and 233 determine whether or not a trigger signal is input as shown in FIG. 16 (S21). When it is determined that the trigger signal has not been input (S21: NO), this process is repeated until it is determined that the trigger signal has been input.

  On the other hand, when it is determined that the trigger signal is input (S21: YES), the sampling time adjustment units 163e and 233e shorten the sampling time from the normal sampling time and measure the pressure with the shortened sampling time (S22). ). Specifically, the sampling time is reduced from 10 seconds to 1 microsecond.

  Thereafter, the gas leak / gas appliance determination units 163d and 233d determine whether or not a minute time has elapsed (S23). If it is determined that the minute time has not elapsed (S23: NO), the process proceeds to step S22. In step S22, the pressure sampling time is shortened, but the flow rate sampling time may be shortened instead of the pressure sampling time.

  When it is determined that a minute time has elapsed (S23: YES), the determination units 163 and 233 perform a gas leak / gas appliance determination (S24). By this gas leak / gas appliance determination, the gas leak and the gas appliance 240 to be used are determined, and it is determined whether or not the gas appliance 240 accompanied by a fire is used. Then, the process shown in FIG. 16 ends.

FIG. 17 is a first flowchart showing details of the gas leakage / gas appliance determination shown in step S24 of FIG. 16, and shows the first method. First, the generation units 165 and 235 determine the frequency ω _{d of the} damped vibration, the gain K, and the damping ratio ζ (S31). At this time, the generation units 165 and 235 may calculate the frequency ω _{d of the} damped vibration, the gain K, and the damping ratio ζ based on the equations (3) to (5), or may be obtained from the equation (6). May be.

Next, the generation units 165 and 235 generate a gas leakage vibration waveform based on the second-order delay step response equation from the damping vibration frequency ω _d , gain K, and damping ratio ζ determined in step S31. (S32). At this time, the generating units 165 and 235 generate the gas leakage vibration waveform by substituting the damping vibration frequency ω _d , the gain K, and the damping ratio ζ determined in step S31 into Equation (2).

  Then, the gas leakage / gas appliance determination units 163d and 233d obtain the equation (1) based on the gas leakage vibration waveform determined in step S32 and the waveform including the measurement value measured in step S12 of FIG. A continuous NCC is calculated (S33). Next, the gas leak / gas appliance determination units 163d and 233d determine a representative value of the continuous NCC and determine whether the representative value is equal to or greater than a threshold value (S34).

  If it is determined that the representative value is greater than or equal to the threshold (S34: YES), the gas leak / gas appliance determination unit 163d, 233d determines that a gas leak has occurred (S35). Thereafter, the process shown in FIG. 17 ends.

  When it is determined that the representative value is not equal to or greater than the threshold value (S34: NO), the gas leakage / gas appliance determination unit 163d, 233d reads the similarity transition data for each gas appliance from the similarity transition storage units 166, 236 (S36). . Next, the gas leak / gas appliance determination unit 163d, 233d identifies the closest NCC data calculated in step S33 among the continuous NCC data for each gas appliance read in step S36, and determines the gas appliance 240 to be used. Judgment is made (S37). When it is determined that the gas appliance 240 accompanied by pilot ignition is used in the process of step S37, “YES” is determined in step S6 of FIG. Then, the process shown in FIG. 17 ends. If it is determined in step S37 that the gas appliance 240 accompanied by a fire has been used, “YES” is determined in step S16 of FIG. Then, the process shown in FIG. 17 ends.

  FIG. 18 is a second flowchart showing details of the gas leakage / gas appliance determination shown in step S24 of FIG. 16, and shows the second method. As shown in FIG. 18, first, the gas leak / gas appliance determination units 163d and 233d perform Fourier transform on the waveform of the gas pressure measured in step S22 of FIG. 16 (S41).

  Thereafter, the gas leak / gas appliance determination units 163d and 233d read out the spectrum data at the time of gas leak stored in the spectrum data storage units 167 and 237 (S42). Then, the gas leak / gas appliance determination unit 163d, 233d calculates the similarity between the spectrum data obtained by the Fourier transform in step S41 and the spectrum data read in step S42 (S43). This similarity may be the above NCC, or may be calculated by another calculation method. Next, the gas leak / gas appliance determination units 163d and 233d determine whether or not the similarity calculated in step S33 is greater than or equal to a specific value (S44).

  When it is determined that the similarity calculated in step S43 is greater than or equal to a specific value (S44: YES), the gas leak / gas appliance determination unit 163d, 233d determines that a gas leak has occurred (S45). Then, the process shown in FIG. 18 ends.

  By the way, when it is determined that the similarity calculated in step S43 is not greater than or equal to the specific value (S44: NO), the gas leakage / gas appliance determination unit 163d, 233d reads the spectrum data for each gas appliance 240 (S46), The similarity with each spectrum data is calculated (S47). Then, the gas leakage / gas appliance determination units 163d and 233d determine that the type of gas appliance 240 indicated by the spectrum data having the maximum similarity is used (S48). When it is determined that the gas appliance 240 accompanied by pilot ignition is used in the process of step S48, “YES” is determined in step S6 of FIG. Then, the process shown in FIG. 18 ends. If it is determined in step S48 that the gas appliance 240 accompanied by a fire is used, “YES” is determined in step S16 of FIG. Then, the process shown in FIG. 18 ends.

  In the processing of steps S37 and S38 shown in FIG. 18, it is determined that the gas appliance 240 indicated by the highest spectrum data is used by obtaining the similarity to all the spectrum data stored for each gas appliance 240. However, the present invention is not limited to this, and the degree of similarity with the stored spectrum data for each gas appliance 240 is sequentially obtained, and the gas appliance 240 indicated by the spectrum data when the similarity becomes equal to or greater than a predetermined value. It may be determined that it has been used, and thereafter the calculation of the similarity may be stopped. This is because by doing so, the number of similarities calculated can be reduced, leading to a reduction in power consumption.

  Furthermore, in this embodiment, the waveform obtained by the electrical signals from the pressure sensors 162 and 232 is Fourier transformed to determine the type of the gas appliance 240 and to determine the gas leakage. However, since there is a certain correlation between the pressure and the flow rate, the waveform obtained from the electrical signals from the flow rate sensors 161 and 231 is Fourier transformed to determine the type of the gas appliance 240 and to determine the gas leak. May be.

  Thus, according to the leak location specifying system and the leak location specifying method according to the present embodiment, the micro leak determining device 160 that determines micro leak in the gas flow path 120 and the micro leak in each individual gas flow path 210 are detected. Since a plurality of gas meters 230 to be determined are provided, for example, when leakage is determined in any one of the plurality of gas meters 230, it can be determined that leakage has occurred in the individual gas flow path 210 of the house 2. In particular, when it is determined that there is no leakage in the plurality of gas meters 230 and it is determined that there is a leakage in the minute leakage determination device 160, it can be determined that there is a leakage in the gas flow path 120 instead of the individual gas flow path 210. . As described above, from the result of the leakage determination of each of the devices 160 and 230, it is possible to specify an approximate leakage location, and it is possible to simplify the specification of the leakage location.

  In addition, since the gas management center 300 that acquires the determination results of the minute leaks from the plurality of gas meters 230 and the minute leak judgment device 160 and identifies the leaked portion is provided, it is possible to obtain a general leak without requiring a gas operator's confirmation work. The location can be specified, and the leakage location can be further simplified.

  In addition, if the minute flow rate F51 is detected within the first predetermined time after the flow rate exceeding the minute flow rate (for example, a flow rate of at least 50 L / h, preferably a flow rate of 100 L / h or more) F52 is detected, It is determined that the flow rate F51 is not a flow rate due to minute leakage. Here, in a gas appliance (for example, a gas stove or gas table) 240 accompanied with a torch, a large flow rate F52 flows at the time of ignition, and then a fine flow rate F51 tends to flow by adjusting the heating power to become a torch. As described above, the flow rate of the gas appliance 240 accompanied by the hot flash shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate F51 is not caused by minute leakage but caused by hot water. Therefore, when such a flow rate transition is observed, it can be determined that the minute flow rate F51 is not due to minute leakage, so that the determination accuracy of minute leakage can be improved.

  In addition, a flow rate that exceeds the micro flow rate (for example, a flow rate of at least 50 L / h, preferably a flow rate of 100 L / h or more) F42 is detected within the second predetermined time after the micro flow rate F41 is detected, and then the flow rate. Is returned to the minute flow rate F41, it is determined that the minute flow rate F41 is a flow rate due to pilot ignition. Here, in the gas appliance 240 accompanied by pilot ignition, first, a small flow rate F41 flows due to pilot ignition, and then a large flow rate F42 tends to flow due to ignition of the main body appliance. In addition, when the use of the appliance ends, the main appliance tends to return to the minute flow rate F41 again by shifting from the ignition state to the fire extinguishing state. Thus, in the gas appliance 240 accompanied by pilot ignition, the flow rate shows the above transition. For this reason, when this flow rate transition is obtained, it can be inferred that the minute flow rate F41 is not due to minute leakage but due to pilot ignition. Therefore, when such a flow rate transition is observed, it is possible to improve the determination accuracy of the minute leakage by determining that the minute flow rate F41 is not due to the minute leakage.

  Further, when it is determined that the gas appliance 240 accompanied by pilot ignition is used and / or when it is determined that the gas appliance 240 accompanied by flash fire is used, the generated minute flow rate is slightly leaked. Judge that the flow rate is not. For this reason, when it is determined that the gas appliance 240 accompanied by pilot ignition or torching is used, the possibility that a further minute leakage has occurred can be denied. Therefore, it is possible to further improve the accuracy of determining a minute leak.

  Moreover, the used gas appliance 240 is judged based on the waveform measured during the minute time from the time of the predetermined change or more of at least one of flow volume and pressure. Here, when the gas appliance 240 starts to be used, it tends to show a waveform specific to the gas appliance in a minute time immediately after the start (for example, 2 seconds at the maximum). For this reason, the gas appliance 240 can be determined in a short time by determining the gas appliance 240 based on the waveform in the minute time.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  For example, in the present embodiment, the degree-of-similarity transition is calculated by the expression (1). However, the present invention is not limited to this, and the degree-of-similarity transition may be calculated by another method.

  Further, in the present embodiment, the gas leak / gas appliance determination units 163d and 233d determine the similarity when there is no data similar to the calculated continuous NCC among the continuous NCC data stored in the similarity transition storage units 166 and 236. It may be determined that the gas appliance 240 indicated by the continuous NCC data stored in the transition storage units 166 and 236 is insufficient. Similarly, it may be determined that there is a shortage in the gas appliance 240 for the spectrum data.

  In this embodiment, the example in which the fuel gas is LP gas has been described. However, the present invention is not limited to this, and the present invention can also be applied to the case of city gas.

  In the present embodiment, the minute time is set to 2 seconds at the maximum, but the present invention is not limited to this and may be a longer time such as several tens of seconds.

  In the present embodiment, the gas leak / gas appliance determination units 163d and 233d calculate the similarity in the entire frequency range of the spectrum data. However, the present invention is not limited to this, and the similarity is calculated only in a part of the frequency range. May be. For example, since the water heater has a feature that a large amplitude can be obtained in the spectrum data even in the frequency range of 100 Hz or higher, the gas appliance 240 to be used is also specified by calculating the similarity of the spectral data in the frequency range of 100 Hz or higher. be able to. In this way, the calculation amount can be reduced by calculating the similarity only in a part of the frequency range.

  Further, the gas leak / gas appliance determination units 163d and 233d determine the gas leak and the gas appliance 240 to be used from the similarity transition (continuous NCC) and the spectrum data. Alternatively, the waveform at a very short time as shown in FIG. 9 may be directly stored, and the gas leakage and the gas appliance 240 to be used may be determined from the similarity between the waveforms. Furthermore, the gas leak and the gas appliance 240 to be used may be determined from the direct characteristics of the waveform such as a specific point of the waveform.

  Further, in the present embodiment, the gas leak / gas appliance determination units 163d and 233d determine the used gas appliance 240 based on the waveform obtained during the minute time from the times t41 and t51 in FIG. Yes. This is because, as described above, the gas appliance 240 shows a specific vibration waveform for each gas appliance 240 in a minute time immediately after the start of use. However, the present invention is not limited to this, and the used gas appliance 240 may be determined based on the waveform obtained during the minute time from time t44, t54. This is because the gas appliance 240 shows a unique vibration waveform for each gas appliance 240 even during a very short time immediately after the end of use, as in the beginning of use.

  Further, when determining the gas appliance 240 from the vibration waveform obtained during the minute time immediately after the end of use, the sampling time adjustment units 163e and 233e shorten the sampling time from the normal sampling time by the minute time immediately after the end of use. It is desirable to do. This is because it is possible to prevent the leakage of the vibration waveform obtained during the minute time immediately after the end of use.

DESCRIPTION OF SYMBOLS 1 ... Gas supply system 2 ... House 100 ... Supply side equipment 110 ... Gas cylinder (gas supply source)
DESCRIPTION OF SYMBOLS 120 ... Gas flow path 121 ... Main flow path 122 ... Bypass flow path 130-150 ... Pressure regulator 160 ... Micro leak judgment apparatus 161, 231 ... Flow rate sensor 162, 232 ... Pressure sensor 163, 233 ... Judgment part 163a, 233a ... Pilot ignition determination unit 163b, 233b ... Flash fire determination unit 163c, 233c ... Micro leak determination unit 163d, 233d ... Gas leak / gas appliance determination unit (gas appliance determination means)
163e, 233e ... sampling time adjustment units 164, 234 ... trigger signal generation units 165, 235 ... generation units 166, 236 ... similarity transition storage units 167, 237 ... spectrum data storage units 168, 238 ... flow rate value storage unit 200 ... housing Side equipment 210 ... Multiple individual gas flow paths 220 ... Multiple valves 230 ... Multiple gas meters (Multiple individual microleakage determination devices)
240 ... multiple gas appliances 300 ... gas management center (leak location identifying means)

Claims (6)

A leak location identifying system for identifying a location where a micro leak occurs in a housing facility that supplies fuel gas from a gas supply source to a plurality of houses,
A gas flow path for supplying fuel gas from a gas supply source to a plurality of houses,
A plurality of individual gas passages for supplying fuel gas flowing through the gas passages to a plurality of houses;
A micro leak determining device provided on the gas flow path for determining micro leaks in the gas flow path;
A plurality of individual micro-leakage determination devices that are provided on each of the plurality of individual gas channels and determine micro-leakage in each individual gas channel ;
When at least one of the plurality of individual micro leak determination devices and the micro leak determination device detects the micro flow rate within a first predetermined time after the flow rate exceeding the micro flow rate is detected, the micro flow rate is Judge that the flow rate is not due to minute leakage
Leak site identification system, characterized in that. The leak location according to claim 1, further comprising: a leak location specifying means for acquiring a determination result of the micro leak from the plurality of individual micro leak determination devices and the micro leak determination device and specifying the leak location. Specific system. At least one of the plurality of individual micro leak determination devices and the micro leak determination device detects a flow rate exceeding the micro flow rate within a second predetermined time after the micro flow rate is detected, and then the flow rate is a micro flow rate. If returning to the leakage point locating system according to claim 1 or claim 2, characterized in that it is determined that the minute flow rates is not a flow rate by the minute leakage. A gas appliance judging means for judging the used gas appliance;
At least one of the plurality of individual microleakage determination devices and the microleakage determination device is a gas appliance that is used when the gas appliance determination means determines that a gas appliance that involves pilot ignition is used, and a gas appliance that includes a flashing fire. The leakage location according to any one of claims 1 to 3 , wherein, in at least one of the cases where it is determined that the flow rate has been used, it is determined that the generated minute flow rate is not a flow rate due to minute leakage. Specific system. The gas appliance determination unit, based on the flow rate and pressure of at least one of the waveform measured during small time from a predetermined or more changes, in claim 4, characterized in that determining the gas appliance used Leakage location identification system described. A leak location identifying method for identifying a location where a micro leak occurs in a housing facility that supplies fuel gas from a gas supply source to a plurality of houses,
A micro-leakage determination step for determining micro-leakage in a gas flow path for supplying fuel gas from a gas supply source to a plurality of houses;
A plurality of individual microleakage determination steps for determining microleakage in each of a plurality of individual gas channels that supply fuel gas that has flowed through the gas channel to a plurality of houses ,
In at least one of the plurality of individual micro leak judgment steps and the micro leak judgment step, if the micro flow rate is detected within a first predetermined time after the flow rate exceeding the micro flow rate is detected, the micro flow rate is Judge that the flow rate is not due to minute leakage
Leak site identification method characterized by.

Images