JP2008224278A - Gas leak discriminator and gas supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set limits on integrated flow independently of installation environment conditions, etc. if there is a suspicion of gas leak, thereby enhancing safety and convenience. <P>SOLUTION: This gas leak discriminator 10 is equipped with: an ultrasonic flow meter 11 connected to a gas supply pipe 20 for measuring an instantaneous flow of gas; a flow calculation part 12 for calculating a flow value, an integrated flow value, and a flow difference value from the instantaneous flow; an appliance discrimination part 13 for discriminating a used gas appliance from the flow changing characteristic of the flow value; a storage part 16 for holding flow characteristic information used for gas leak discriminating; a leak discrimination part 14 for discriminating a gas leak by the characteristic information based on flow characteristic values including the flow value and the integrated flow value; and a control part 15 having the function of a security procedure part for executing a security procedure such as warning, gas cutting off, etc. according to the result of gas leak discrimination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas leak determination device and a gas supply system that detect a leak in a gas supply path using a gas meter that measures a gas flow rate installed in a house or the like.

  When using gas appliances, in order to prevent accidents caused by forgetting to turn off the gas or leaking gas, notifications and gas supply should be made in the event of an abnormality at the gas user's home or the center managing the gas supply path. Systems for blocking roads are becoming widespread. As a conventional gas security device, based on the gas flow rate, etc., the gas supply is cut off when a large flow rate flows, or the gas flow is cut off when the gas flows for a long time at a minute flow rate. What shuts off when gas flows for a predetermined time is used.

  In a gas user's house or the like, a gas meter for measuring a gas flow rate is installed at an inlet portion of a gas supply path. Conventionally, as this type of gas meter, a membrane-type gas meter that integrates the amount of gas that flows at a predetermined flow rate is generally used, but recently, an instantaneous flow rate is obtained using an ultrasonic signal, and this instantaneous flow rate is calculated. There has also been proposed an ultrasonic gas meter that measures the flow rate of gas by integrating.

  In addition, as a system using a gas meter, an appliance discriminating system that discriminates an appliance used by a user has been proposed (see, for example, Patent Document 1). By discriminating the appliances in this way, it is possible to realize functions such as grasping the usage status of the specified appliances and charging for the specified appliances. It is also possible to set a usage time limit for the specified appliance.

When discriminating gas leakage, in addition to the case of detecting a minute flow rate, the conventional apparatus determines the coincidence of flow rate change characteristics such as a rising flow rate waveform when starting the gas appliance, When a flow rate change different from the flow rate change characteristic of the gas appliance occurs, there is one that determines that there is a suspicion of leakage.
Patent No. 3490064 specification

  However, with the conventional gas leak detection device, even if an attempt is made to determine a leak by determining whether the flow rate change characteristics match, the flow rate change characteristics may vary or vary depending on the conditions of the installation environment, such as the situation of the installation location or the season There was a possibility that misjudgment as a gas leak occurred although it was not a gas leak.

  The present invention has been made in view of the above circumstances, and it is possible to improve the safety and convenience by setting the limit of the integrated flow rate when there is a suspicion of gas leakage regardless of the conditions of the installation environment. An object of the present invention is to provide a gas leak discrimination device and a gas supply system.

The gas leakage determination device of the present invention is connected to a gas supply pipe and calculates a flow rate value and an integrated flow rate value based on a flow rate measurement unit that measures a gas flow rate and an instantaneous flow rate of the gas measured by the flow rate measurement unit. A flow rate calculation unit; an appliance discrimination unit that discriminates an appliance that uses gas flowing through the gas supply pipe from a flow rate change characteristic of the flow rate value; a storage unit that holds flow rate characteristic information used for discrimination of gas leakage; and the flow rate And a leak determination unit that determines a gas leak based on the flow rate characteristic information based on the flow rate characteristic value including the value and the integrated flow rate value.
As a result, by determining the gas leakage based on the flow characteristic value including the flow value and the integrated flow value, the limit of the integrated flow is set when there is a suspicion of gas leakage regardless of the conditions of the installation environment. And convenience can be improved.

Further, the present invention is the above-described gas leak determination device, wherein the storage unit holds determination data including a flow rate determination value as the flow rate characteristic information, and the leak determination unit includes the flow rate characteristic value. As described above, the flow rate value in the determined appliance is used to determine a gas leak when a flow rate characteristic value different from the flow rate determination value of the flow rate characteristic information is generated.
As a result, when a flow characteristic value different from the flow judgment value of the predetermined flow characteristic information is generated, it is possible to judge gas leakage as an abnormal flow rate.

Further, the present invention is the above-described gas leak determination device, wherein the storage unit holds determination data including an integrated flow rate determination value as the flow rate characteristic information, and the leak determination unit is determined as described above. When the flow rate characteristic value matches with the determination data of the flow rate characteristic information using the flow rate characteristic value in the measured instrument, monitoring of the flow rate change is started, and the calculated integrated flow rate value is the flow rate characteristic value. It includes what determines a gas leak according to a flow rate change until it becomes an integrated flow rate determination value of information.
As a result, when the determination data for the predetermined flow rate characteristic information matches the flow rate characteristic value, the flow rate change is monitored, and the gas flow is measured until the integrated flow rate value becomes the integrated flow rate determination value for the flow rate characteristic information. Leakage can be determined.

Further, the present invention is the above-described gas leakage determination device, wherein the leakage determination unit includes at least one of a flow rate value, a flow rate change characteristic value, and an instantaneous flow rate value in the determined appliance as the flow rate characteristic value. The value including one of them is used, and when the flow rate characteristic value matches the determination value of the flow rate characteristic information, the flow rate change monitoring is started.
As a result, when at least one of the flow rate value, the flow rate change characteristic value, and the instantaneous flow rate value is used as the flow rate characteristic value, the coincidence with the judgment value of the flow rate characteristic information is determined, and the flow rate value corresponds to the instrument flow rate It becomes possible to start monitoring the flow rate change.

Further, the present invention is the gas leak determination device described above, wherein the leak determination unit starts monitoring the flow rate change, and then the calculated integrated flow value is equal to or greater than the integrated flow rate determination value of the flow rate characteristic information. This includes determining gas leakage when no change in flow rate occurs.
As a result, the flow rate change is monitored, and when the flow rate change does not occur until the integrated flow rate value becomes equal to or higher than the integrated flow rate judgment value of the flow rate characteristic information, it is determined that the appliance is not in a normal use state and gas leakage is determined. It becomes possible.

Further, the present invention is the above-described gas leakage determination device, wherein the leakage determination unit starts monitoring the flow rate change, and then the calculated integrated flow rate value is the integrated flow rate determination value of the flow rate characteristic information. This includes resetting the monitoring of the flow rate change when a flow rate change has occurred.
As a result, when monitoring the flow rate change, if the flow rate change occurs before the integrated flow rate value reaches the integrated flow rate judgment value of the flow rate characteristic information, the monitoring is reset, and the flow rate value corresponds to the instrument flow rate. It becomes possible to identify the usage state of the gas.

Further, the present invention includes the above-described gas leak determination device including a security processing unit that executes a security process based on a gas leak determination result by the leak determination unit.
Accordingly, it is possible to perform an appropriate security process when a gas leak is determined.

In addition, the present invention is the gas leakage determination device described above, wherein the security processing unit includes, as the security processing, a warning, a cutoff of gas supply, a shutdown after warning, a report to a user, a report to a center. Includes processing that includes at least one.
As a result, when a gas leak is determined, for example, a warning is given, the gas supply is shut off, a report is sent to the user using a telephone line, etc. Various security processes such as reporting can be performed.

  According to the present invention, a gas leakage determination device and a gas supply capable of setting the limit of the integrated flow rate when there is a suspicion of gas leakage regardless of the conditions of the installation environment, etc., and improving safety and convenience Can provide a system.

  FIG. 1 is a block diagram showing a configuration of a gas leak determination device according to an embodiment of the present invention. In the present embodiment, a configuration example of a gas leak determination apparatus using a gas meter installed in a gas user's house or the like is shown.

  The gas leak discrimination device 10 of this embodiment is provided in the middle of a gas supply pipe 20 laid in a user's house or the like, and a pipe A downstream of the gas supply pipe 20 includes a tool A21 and a tool as a plurality of gas tools. B22 and instrument C23 are connected. The gas leak determination device 10 is installed at a predetermined position outdoors or indoors. The number of gas appliances to be connected is not limited to the illustrated example, and is arbitrary. In addition, the user home includes not only a general residential house but also an apartment house, a store, a factory, and other various facilities.

  The gas leak discriminating apparatus 10 includes an ultrasonic flow meter 11, a flow rate calculating unit 12, an appliance discriminating unit 13, a leak judging unit 14, a control unit 15, a storage unit 16, a display unit 17, a seismic device 18, and a shut-off valve 19. Configured. The ultrasonic flowmeter 11 is connected in the path of the gas supply pipe 20 and, as will be described later, obtains a propagation time difference caused by the gas flow in the gas supply pipe 20 using an ultrasonic signal, and detects an instantaneous gas flow rate. To do. Based on the detected instantaneous flow rate, the flow rate calculation unit 12 calculates a flow rate value by means of an average of the instantaneous flow rate, integrates the instantaneous flow rate to calculate an integrated flow rate value, or a flow rate difference value for device discrimination For example, various calculations relating to the flow rate are performed. Here, the ultrasonic flowmeter 11 realizes the function of the flow rate measuring unit.

  The appliance discriminating unit 13 determines the flow rate change characteristics of the gas flow rate such as the flow rate change amount and the change time based on the stored judgment value for each appliance based on the calculated flow rate difference value, and the gas is supplied to the gas supply pipe 20. The gas appliance used when flowing is discriminated. The leak determination unit 14 determines whether or not a gas leak has occurred based on the flow characteristic value including the calculated gas flow value and the integrated flow value.

  The control unit 15 has a function of a security processing unit, and performs security processing such as warning and gas shutoff based on the gas leakage determination result by the leakage determination unit 14 in addition to the operation control of each part of the gas leakage determination device. Is. The storage unit 16 includes instrument discrimination information such as a judgment value used for instrument discrimination, flow rate characteristic information used for leakage judgment, instantaneous flow rate value information measured by the ultrasonic flowmeter 11, and gas flow rate value calculated by the flow rate calculation unit 12. Various information used in the gas leak discriminating apparatus 10 such as information, accumulated flow value information, flow rate information such as flow rate difference value information, and history information on used equipment and usage status is stored. Here, the control unit 15, the flow rate calculation unit 12, the appliance determination unit 13, and the leakage determination unit 14 are configured by a processor and an operation program that constitute a microcomputer (microcomputer) and the like, and the processor executes a predetermined operation program. Each function is realized by performing corresponding processing. The storage unit 16 is configured by a memory such as a flash ROM or a RAM.

  The display unit 17 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 18 detects vibration such as an earthquake and outputs a detection signal to the control unit 15. The shut-off valve 19 is connected in the path of the gas supply pipe 20 and shuts off the gas supply by closing the gas supply pipe 20 based on an instruction from the control unit 15.

  The operations of the ultrasonic flowmeter 11 and the flow rate calculation unit 12 will be described in detail. FIG. 2 is a configuration diagram showing a schematic configuration of the ultrasonic flowmeter 11.

  The ultrasonic flow meter 11 has a measurement flow path 32 having a rectangular cross section communicating with the gas supply pipe 20, and a pair of super flow meters is provided on the upstream side and the downstream side of the flow path walls facing each other. Sonic 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 φ ((1 / t1) − (1 / t2)) (1)
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 varies depending on the gas appliance, reducing the measurement time interval is advantageous in terms of instantaneous instrument discrimination, 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 the present embodiment, the periodic instantaneous flow rate at intervals of 2 seconds is measured, 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 appliance determination unit 13 will be described in detail. FIG. 3 is a characteristic diagram showing a change in gas flow rate and a change in difference value when using a gas appliance, and FIG. 4 is a characteristic diagram showing a change in gas flow rate and a change in difference value when using a plurality of gas appliances.

  In FIG. 3, the solid line indicates the instantaneous flow rate value of the gas measured by the ultrasonic flowmeter 11, and the broken line indicates the differential value at that time, that is, the difference value for each predetermined measurement time interval. The difference value is expressed with a peak on the plus side when the gas appliance is started, and is expressed with a peak on the minus side when the gas appliance is stopped. Here, when the difference value is greater than or equal to a predetermined value (change determination value), it is determined that there is a change in the gas flow rate and the change of the appliance or the state is determined.

  As shown in FIG. 4, based on the difference value of the instantaneous flow rate value of gas, for example, even when three appliances (A, B, C) are used at the same time, activation and stop of each gas appliance and output are performed. Changes in gas flow rate during adjustment can be detected. The form of control in the gas flow rate adjustment at the time of starting and ending and at the time of output adjustment is different for each gas appliance, and the flow rate change characteristics of the gas flow rate are different. Therefore, it is possible to determine the type of gas appliance by determining the gas flow rate and its flow rate change characteristics.

  For example, a gas stove, a fan heater using gas combustion heat as a heat source, and a gas water heater can be identified. The gas stove has a single function for cooking and the fan heater has a single function such as for hot air heating, but the gas water heater has two functions for hot water supply and floor heating. In the floor heating, a heat medium flow path is formed on the back side of the floor, and the heat medium flowing therethrough is heated with hot water boiled by a gas water heater. And for hot water supply and floor heating, the start-up or control pattern is different, and naturally there is a difference in the change amount and change time of the difference value. Therefore, when the gas appliance is a gas water heater, it can be determined whether it is for hot water supply or floor heating, based on the number of times the difference value is continuously generated or the continuous generation time. Note that the difference value may be a negative difference at the time of stopping or ending the control as well as at the time of starting or controlling.

  Next, the operation of the leak determination unit 14 will be described in detail. FIG. 5 is a diagram showing an example of flow rate characteristic information used for determining gas leakage in the present embodiment. The storage unit 16 stores and stores flow rate characteristic information including determination data as shown in FIG. The leak determination unit 14 uses this flow rate characteristic information to determine whether there is a gas leak based on the flow rate value set for each appliance type and the flow rate change until a predetermined integrated flow rate value is reached.

  As the flow rate characteristic information, first, a flow rate determination value Qr, which is a standard flow rate value set for each appliance type, is stored as first determination data. For example, 150 L (liter) / h (time) corresponding to the fan heater, 100 L / h corresponding to the gas table, and the like are set. The flow rate determination value Qr may be set with a certain width. Then, an integrated flow rate determination value Qmax that defines the upper limit of the flow rate when the flow rate is normal is set as second determination data. Here, a plurality of integrated flow rate determination values may be set for each type of gas appliance such as Qmax (A) and Qmax (B), or one integrated flow rate determination value Qmax may be set.

  The leak determination unit 14 first determines whether or not the flow rate value Qm measured by the ultrasonic flowmeter 11 and the flow rate calculation unit 12 matches the flow rate determination value Qr set for each appliance type. Here, when the flow rate value Qm does not coincide with the flow rate determination value Qr that has been set and stored, and there is no corresponding device, the measured flow rate value Qm is abnormal, and thus it is determined that there is a gas leak. When the flow rate value Qm matches the flow rate determination value Qr and corresponds to the instrument flow rate, the subsequent flow rate change is monitored. In this state, the flow rate value Qm is integrated, and if there is a change in the flow rate until the integrated flow rate value Qn reaches the stored integrated flow rate determination value Qmax, the gas appliance is in a normal use state. Is detected, and it is determined that there is no gas leakage, and monitoring of the flow rate change is reset. On the other hand, if there is no change in the flow rate even when the flow rate integrated value Qn becomes equal to or greater than the integrated flow rate determination value Qmax, it is determined that there is a suspicion of gas leakage, assuming that it is different from the normal use of the gas appliance.

  The condition for starting the monitoring of the flow rate change is a case where the judgment value of the predetermined flow rate characteristic coincides with the flow rate value Qm in the steady state during the normal operation as described above. It is also possible to use flow rate characteristic values relating to various flow rates such as flow rate patterns and instantaneous flow rate values.

  FIG. 6 is a diagram showing an example of gas flow rate change characteristics, and FIG. 7 is a diagram showing an integrated flow rate judgment value for leak judgment. When the gas flow rate is a flow rate pattern as shown in FIG. 6, for example, at the timing a when the gas appliance is stably operated, the measured flow rate value Qm is compared with the flow rate determination value Qr that is set and stored, and the flow rate value Qm To determine whether it corresponds to the instrument flow rate. If the flow rate value Qm corresponds to the instrument flow rate, the flow rate change is monitored while integrating the flow rate value Qm, and is there a change in flow rate until the integrated flow rate value Qn reaches the stored integrated flow rate determination value Qmax? It is determined whether the gas flow is due to the use of a normal gas appliance or whether the gas leaks, depending on whether there is a change in flow rate.

  FIG. 8 is a flowchart showing an operation procedure of the gas leakage determination apparatus of the present embodiment. First, the instantaneous flow rate is measured at predetermined measurement time intervals by the ultrasonic flow meter 11 and the flow rate calculation unit 12, and an integrated value or a difference value of the instantaneous flow rate is calculated (step S1). Then, the appliance discriminating unit 13 discriminates the gas appliance used from the flow rate change characteristics such as the flow rate change amount and the change time based on the instantaneous flow rate difference value (step S2). Next, the leakage determination unit 14 compares the measured flow value Qm with the flow determination value Qr to determine whether or not the flow value Qm is abnormal (step S3). If there is an abnormality in the flow rate value Qm, it is determined that there is a gas leak (step S8).

  When the flow rate value Qm is equivalent to the appliance flow rate in step S3, the leak determination unit 14 starts monitoring the flow rate change (step S4). Then, while integrating the flow value Qm, it is determined whether there is a change in the flow rate (step S5) and whether the integrated flow value Qn is equal to or greater than the integrated flow rate determination value Qmax (step S6). If a change in flow rate is detected in step S5, monitoring of the change in flow rate is reset (step S7), and then the process returns to step S1 to repeat the same processing. Also, when the integrated flow value Qn is less than the integrated flow determination value Qmax, the process returns to step S1 and the same processing is repeated.

  If no change in the flow rate is detected in steps S5 and S6 and the integrated flow rate value Qn becomes equal to or greater than the integrated flow rate determination value Qmax, the leak determination unit 14 determines that there is a suspicion of gas leak (step S8). When a gas leak is determined, a gas leak determination signal is output to the control unit 15. When the control unit 15 receives the gas leak determination signal, the control unit 15 performs a security process such as warning or interruption. As the security process, various processes and combinations thereof, such as an automatic return confirmation function for performing a warning, blocking after performing a warning, blocking, and restoring again after the blocking, can be considered. When giving a warning, it is also possible to notify the fixed telephone or mobile phone registered by the user of the interruption or the advance notice of the interruption, or to notify the center managing the gas supply path.

  When a warning is issued, a warning instruction signal is sent from the control unit 15 to the display unit 17, and in response to the warning instruction signal, the display unit 17 turns on an LED or displays characters or pictures on a liquid crystal display. Is notified. Moreover, you may warn using a sound etc. When shutting off, the control unit 15 sends a shutoff instruction signal to the shutoff valve 19, and in response to the shutoff instruction signal, the shutoff valve 19 is driven to close the gas supply pipe 20 and shut off the gas supply.

  As described above, according to the present embodiment, the ultrasonic flow meter 11 and the flow rate calculation unit 12 calculate the gas flow value and the integrated flow value, and the leak determination unit 14 uses the flow rate value and the integrated flow value. Determine leaks. At this time, it is determined whether there is an abnormality in the flow rate value by comparison with the flow rate determination value set for each appliance type, and the flow rate change until the integrated flow rate value reaches the predetermined integrated flow rate determination value is monitored. If there is no change in the flow rate while the flow rate continues, it is determined that there is a suspicion of gas leakage. This makes it possible to accurately determine the gas leak without being affected by the conditions of the installation location, the conditions of the installation environment such as the season, and the like. In addition, even when the rise of gas leak is not detected and the start point of gas leak is unknown, a safe measure against gas leak is taken by monitoring the flow rate after the occurrence of a predetermined flow rate judgment value. It is possible.

  It should be noted that the present invention is not limited to those shown in the above-described embodiments, and those skilled in the art can also make changes and applications based on the description in the specification and well-known techniques. Yes, included in the scope of protection.

  The present invention has the effect of setting the limit of the integrated flow rate when there is a suspicion of gas leakage regardless of the conditions of the installation environment, etc., and improving safety and convenience. The present invention is useful for a gas leakage determination device that detects a leakage of a gas supply path using a gas meter that measures the gas flow rate installed, a supply system that supplies gas, and the like.

The block diagram which shows the structure of the gas leak discrimination | determination apparatus which concerns on embodiment of this invention. The block diagram which shows schematic structure of the ultrasonic flowmeter in this embodiment The characteristic view which shows the change of the gas flow rate at the time of gas appliance use in this embodiment, and the change of a difference value The characteristic view which shows the change of the gas flow rate at the time of use of a plurality of gas appliances in this embodiment, and the change of a difference value The figure which shows an example of the flow volume characteristic information used for determination of the gas leak in this embodiment The figure which shows an example of the flow volume change characteristic of the gas in this embodiment The figure which shows the integrated flow volume determination value for the leak determination in this embodiment The flowchart which shows the operation | movement procedure of the gas leak discrimination | determination apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas leak discrimination | determination apparatus 11 Ultrasonic flowmeter 12 Flow rate calculating part 13 Instrument discrimination | determination part 14 Leak determination part 15 Control part (security process part)
16 Storage unit (flow rate characteristic information)
17 Display unit 18 Seismic device 19 Shut-off valve 20 Gas supply pipe 21, 22, 23

Claims (9)

A flow rate measuring unit connected to the gas supply pipe for measuring the gas flow rate;
A flow rate calculation unit that calculates a flow rate value and an integrated flow rate value based on the instantaneous flow rate of the gas measured by the flow rate measurement unit;
An appliance discriminating unit that discriminates an appliance that uses the gas flowing through the gas supply pipe from the flow rate change characteristic of the flow rate value;
A storage unit for holding flow rate characteristic information used for determining gas leakage;
A leak determination unit that determines a gas leak based on the flow rate characteristic information based on the flow rate characteristic value including the flow rate value and the integrated flow rate value;
A gas leakage discrimination device comprising: The gas leak determination device according to claim 1,
The storage unit holds determination data including a flow determination value as the flow characteristic information.
The leak determination unit determines a gas leak when a flow rate characteristic value different from the flow rate determination value of the flow rate characteristic information is generated using the flow rate value of the determined appliance as the flow rate characteristic value. Gas leak detection device. The gas leak determination device according to claim 1,
The storage unit holds determination data including an integrated flow determination value as the flow characteristic information.
The leak determination unit starts monitoring the flow rate change when the flow rate characteristic value matches with the determination data of the flow rate characteristic information using the flow rate characteristic value in the determined appliance, and the calculation A gas leak discriminating apparatus for judging gas leak according to a flow rate change until the integrated flow rate value becomes an integrated flow rate judgment value of the flow rate characteristic information. The gas leak determination device according to claim 3,
The leak determination unit uses, as the flow rate characteristic value, a value including at least one of a flow rate value, a flow rate change characteristic value, and an instantaneous flow rate value in the determined appliance, A gas leak determination device that starts monitoring a flow rate change when the determination value of the flow rate characteristic information matches. The gas leak determination device according to claim 3,
The leak determination unit determines a gas leak when the flow rate change does not occur until the calculated integrated flow rate value becomes equal to or greater than the integrated flow rate determination value of the flow rate characteristic information after monitoring the flow rate change. Leak detection device. The gas leak determination device according to claim 3,
The leak determination unit starts monitoring the flow rate change when the flow rate change occurs until the calculated integrated flow rate value reaches the integrated flow rate determination value of the flow rate characteristic information after starting monitoring the flow rate change. Gas leak detection device to be reset. The gas leak determination device according to claim 1,
A gas leak determination apparatus including a security processing unit that executes a security process based on a gas leak determination result by the leak determination unit. The gas leak determination device according to claim 7,
The said security process part is a gas leak determination apparatus which performs the process including at least one of warning, interruption | blocking of gas supply, interruption | blocking after warning, a report to a user, and a report to a center as said security process.   A gas supply system using the gas leak determination device according to claim 1.

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