JP2000230846A - Gas meter, gas leakage detecting system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable judging whether a gas apparatus is used, and detect suitably gas leakage in accordance with the state of application of the gas apparatus. SOLUTION: The flow rate of gas flowing in a gas channel is detected, on the gas meter side. A signal S1 showing the state of application of a gas apparatus 110 is received with a signal receiving part 164. On the basis of the received signal S1 and the detected flow rate of gas, the state of application of the gas apparatus 110 is judged. Whether a leakage portion of the gas channel exists is judged. Thereby it can be judged whether the gas apparatus 110 is used, and gas leakage can be suitably detected in accordance with the state of application of the gas apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter having a function of detecting leakage of gas flowing through a flow path, a gas leakage detection system and a method thereof.

[0002]

2. Description of the Related Art In recent years, gas meters using a flow meter such as a membrane type flow meter or a fluidic flow meter have been put into practical use. Recently, however, the flow rate of gas flowing through a flow passage has been almost continuously maintained for a predetermined time. 2. Description of the Related Art There is known a gas meter equipped with a microcomputer having a safety function of determining that an abnormality has occurred when the temperature is constant and shutting off a gas flow path. here,
“The gas flow rate is substantially constant” means that the change amount of the gas flow rate passing through the gas meter does not exceed, for example, 3%, and the microcomputer determines that the state within this range is a predetermined time (hereinafter referred to as “the gas flow rate”). , Continuous usable time), the safety valve is closed and the flow path is shut off, assuming that an abnormality such as gas leakage has occurred. On the other hand, when the change amount of the gas flow rate exceeds the above range or when the gas flow rate becomes 0, the microcomputer resets the built-in monitoring timer,
From that point, the continuous usable time is counted up again.

According to this type of gas meter, it is possible to detect an abnormality such as gas leakage in various gas combustion devices and pipes connected to the gas meter, thereby improving safety.

[0004] Conventionally, gas combustion control of gas appliances is performed by turning on and off the combustion itself in many cases. For this reason, if the combustion state of any gas equipment connected downstream of the gas meter changes,
The variation of the gas flow rate detected by the gas meter greatly exceeds the above range, and at this time, the monitoring timer of the microcomputer is reset almost without exception. For this reason, there is almost no possibility of an erroneous shut-off operation in which the gas flow rate is determined to be within the above range and the safety valve is closed and the flow path is shut off even though the gas appliance is actually used.

[0005]

However, recently,
For example, as in the case of an air-conditioning gas appliance such as a hot-water circulation type floor heating system or a gas heat pump (GHP), a gas that does not perform the on / off control as described above but proportionally controls a gas combustion amount according to a required heat amount. Equipment is increasing. In this type of gas equipment, gas combustion often continues for a long time, and the gas usage does not fluctuate as much as the conventional on-off control type gas equipment. There is a possibility of being shut off accidentally as an abnormality such as gas leakage. In addition, the hot water circulation type floor heating system means that hot water is produced by burning gas with a heat source device such as a GCH (gas central heating) boiler, and this hot water is circulated to a floor heating panel laid on the floor to make the room indoors. Is a heating system.

As described above, in the conventional gas meter, when the proportional control type gas equipment is used for a long time, the continuous use time has been exceeded even though no abnormality such as gas leakage has occurred. There is a possibility that the gas flow path may be shut off upon judgment, which is inconvenient for the user.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to determine whether a gas appliance is in use and to appropriately determine whether the gas appliance is in use. An object of the present invention is to provide a gas meter, a gas leak detection system and a method capable of detecting a gas leak.

[0008]

According to a first aspect of the present invention, there is provided a gas meter for detecting a flow rate of a gas flowing through a gas flow path, receiving means for receiving a signal indicating a use state of a gas appliance, and receiving the signal. Based on the reception signal received by the means and the gas flow rate detected by the flow rate detection means, determine the use state of the gas appliance, and determine whether there is a leak in the gas flow path and It is provided with.

In this gas meter, the use state of the gas appliance is determined based on the signal indicating the use state of the gas appliance and the flow rate of the gas flowing through the gas passage, and whether or not there is a leak in the gas passage. Is determined.

According to a second aspect of the present invention, in the gas meter according to the first aspect, the receiving unit includes a plurality of signal receiving units for receiving signals from the plurality of gas appliances for each gas appliance. The means determines the use state of each gas appliance based on the reception signals of each gas appliance received by the plurality of signal receiving units and the gas flow rate detected by the flow rate detection unit. .

In this gas meter, a plurality of signal receiving units receive signals from each of the gas appliances transmitted from the plurality of gas appliances, and a judging means receives the signals of each of the gas appliances received by the plurality of signal receiving units. The use state of each gas appliance is determined based on the received signal and the gas flow rate detected by the flow rate detection means.

According to a third aspect of the present invention, there is provided the gas meter according to the first aspect, further comprising at least one continuous flow in which a gas flow rate is associated with a continuously usable time indicating a time during which the gas can be continuously used. An available time table is provided, and when it is determined that at least the gas appliance is not used, the available time corresponding to the gas flow rate is obtained by referring to the first continuous available time table In addition, it has a function of determining that there is a leak in the gas flow path on condition that the amount of change in the gas flow rate is within a predetermined range over the obtained usable time.

In this gas meter, the determining means
When it is determined that at least the gas appliance is not used, the usable time corresponding to the gas flow rate is obtained by referring to the first continuous usable time table, and the change amount of the gas flow rate is obtained. It is determined that there is a leak in the gas flow path provided that the gas flow path is within a predetermined range over the usable time.

According to a fourth aspect of the present invention, in the gas meter according to the third aspect, when the determining means determines that the gas appliance is used, the gas meter can be used continuously in the first continuously usable time table. The first continuous usable time table is changed so that the time is extended, and it is determined whether or not there is a leak in the gas flow path.

In this gas meter, the determining means
If it is determined that gas equipment is being used, the first
The first continuous usable time table is changed so that the continuous usable time in the continuous usable time table is extended, and it is determined whether or not there is a leak in the gas flow path.

According to a fifth aspect of the present invention, in the gas meter according to the third aspect, when the judging means judges that the gas appliance is used, the gas meter is continuously operated with respect to the first continuously usable time table. The usable time corresponding to the gas flow rate is acquired by referring to the second continuous usable time table in which the usable time is extended, and the change amount of the gas flow rate is within a predetermined range over the acquired usable time. It is determined that there is a leak in the gas flow path on condition that there is a leak.

In this gas meter, the determining means
If it is determined that gas equipment is being used, the first
The usable time corresponding to the gas flow rate is obtained by referring to the second continuous usable time table in which the continuous usable time is extended with respect to the continuous usable time table, and the change amount of the gas flow rate is obtained. It is determined that there is a leak in the gas flow path provided that the gas flow path is within a predetermined range over the usable time.

According to a sixth aspect of the present invention, in the gas meter according to the third aspect, the judging means identifies the type of the gas appliance being used based on the received signal received by the receiving means, and When it is determined that the device is used, the second continuous usable time table for each type of gas equipment whose continuous usable time is extended with respect to the first continuous usable time table is referred to. And obtains a usable time corresponding to the gas flow rate, and determines that there is a leak point in the gas flow path on condition that a change amount of the gas flow rate is within a predetermined range over the obtained usable time. It is like that.

In this gas meter, the judging means
Based on the received signal received by the receiving means, the type of the gas appliance being used is identified, and if it is determined that the gas appliance is being used, the first continuous usable time table The available time corresponding to the gas flow rate is acquired by referring to the second continuous available time table for each type of gas equipment whose continuous available time has been extended, and the change amount of the gas flow rate is obtained. It is determined that there is a leak in the gas flow path provided that the gas flow path is within a predetermined range over the usable time.

[0020] The gas meter according to claim 7 is a gas meter according to claim 1.
7. The gas meter according to 2, 3, 4, 5 or 6, further comprising a flow path shut-off means for shutting off the gas flow path when the judgment means judges that there is a leak in the gas flow path. It is.

In this gas meter, when it is determined by the determining means that there is a leak in the gas flow path, the gas flow path is blocked by the flow path blocking means.

A gas leak detection system according to claim 8 is
A gas leak detection system for detecting a gas leak in a gas flow path to which a gas device is connected on the downstream side, wherein the gas device includes:
A means for transmitting a signal indicating a use state to the gas meter, the gas meter detects a flow rate of gas flowing through the gas flow path, and a reception means for receiving a signal indicating a use state of the gas device, Based on the received signal received by the receiving means and the gas flow rate detected by the flow rate detecting means, the use state of the gas appliance is determined, and the determination of whether or not there is a leak in the gas flow path is performed. Means.

In this gas leak detection system, a signal indicating the use state is transmitted to the gas meter by the gas equipment, and the gas meter uses the signal indicating the use state of the gas equipment and the flow rate of the gas flowing through the gas flow path. ,
The use state of the gas appliance is determined, and a determination is made as to whether or not there is a leak in the gas flow path.

According to a ninth aspect of the present invention, there is provided a method for detecting a gas leak, comprising detecting a flow rate of a gas flowing through a gas flow path, receiving a signal indicating a use state of a gas device, Based on the determination, the use state of the gas appliance is determined, and the determination is made as to whether or not there is a leak in the gas flow path.

In this gas leak detection method, the use state of the gas equipment is determined based on the signal indicating the use state of the gas equipment and the flow rate of the gas flowing through the gas flow path. A determination is made whether there is.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of a main part of a gas leak detection system according to an embodiment of the present invention.
The gas leak detection system according to the present embodiment is a system that detects a gas leak in a gas flow path to which at least one gas appliance 110 is connected on the downstream side on the gas meter side. In the gas leak detection system according to the present embodiment, the signal S indicating the use state of the gas appliance 110 is sent from the gas appliance 110 side.
1 is transmitted to the gas meter side. In the present embodiment, as an example of a gas meter, an example in which a measuring mechanism using a flow sensor and a measuring mechanism using a fluidic element are provided side by side will be described.

As shown in FIG. 1, the gas meter according to the present embodiment has a piezoelectric film sensor 101 for detecting fluidic oscillation (described later) of a fluidic element which is in charge of detecting a flow rate in a large flow rate range, and a low flow rate sensor. Measuring unit 100 having a flow sensor 102 for detecting the flow rate of the area, a display 120 for displaying the integrated flow rate value, and a gas flow path in the gas meter if necessary (not shown in this drawing). ), A valve driving unit 150 for driving the shut-off valve 140, and a control unit 160 for controlling the entire gas meter.

The control section 160 includes a valve opening / closing control section 161 connected to an input end of the valve driving section 150 and a weighing mechanism section 100.
Flow rate calculation unit 162 connected to the piezoelectric film sensor 101 and the flow sensor 102, an integration unit 163 connected to the output terminal of the flow rate calculation unit 162, and a valve opening / closing control unit 161 and a small number of units arranged downstream of the gas meter. Also has a signal receiving unit 164 connected to one gas appliance 110.

The valve opening / closing controller 161 includes a flow rate calculator 162
Is determined based on the flow rate value 166 from the sensor and the presence or absence of the detection signal 167 from the signal receiving unit 164. As a result, when it is determined that the flow path should be blocked, the valve driving signal 165 is determined. The output is output to the valve drive unit 150 to close the shutoff valve 140. The flow rate calculation unit 162 includes the piezoelectric film sensor 101 and the flow sensor 10 of the measurement mechanism unit 100.
The flow rate signal 166 is binarized, and the flow rate value 166 is calculated and output based on one or both of these signals. The accumulator 163 is used for the flow rate calculator 1
The flow rate value 166 from 62 is integrated and output to the display 120.

The signal receiving section 164 receives the signal S1 indicating the use state from at least one gas appliance 110 connected to the pipe on the downstream side of the gas meter, and also receives the signal S1.
Is output to the valve opening / closing control unit 161 to notify that the control signal has been received.

The control unit 160 is constituted by using, for example, a microcomputer, and a ROM (Read Only
The memory is operated by executing a program stored in the memory or the like. Here, the weighing mechanism 1
00 and the flow rate calculating section 162 correspond to “flow rate detecting means” in the present invention, the signal receiving section 164 corresponds to “receiving means” in the present invention, and the shutoff valve 140 and the valve driving section 1
Reference numeral 50 corresponds to the "flow path blocking means" in the present invention. Further, the valve opening / closing control section 161 is the “judgment means” in the present invention.
Corresponding to

The display 120 is, for example, a liquid crystal display (LC).
D), and is configured to display a flow rate integrated value or the like output from the control unit 160.

FIG. 2 shows the valve opening / closing controller 161 in FIG.
Of FIG. As shown in this figure,
The valve opening / closing control unit 161 includes a determination unit 161a to which the flow rate value 166 from the flow rate calculation unit 162 and the detection signal 167 from the signal reception unit 164 are input, a continuous usable time table 161b connected to the determination unit 161a, And a timer 161c.

The determination unit 161a monitors the value of the flow rate value 166 and the presence or absence of the input of the detection signal 167, and when a predetermined condition described later is satisfied, determines that there is a possibility of gas leakage. 165 is supplied to the valve drive unit 150 to drive the shutoff valve 140 to shut off the gas flow path.

The continuous usable time table 161b is, for example, as shown in FIG. 3, in which continuous usable time is set in association with each range of the individual flow rate. It is being referred to. Here, the individual flow rate is defined as a value obtained by integrating the flow rate value 166 from the flow rate calculation unit 162 for a fixed time τ (for example, 30 seconds) at a time exceeding a certain range (for example, 3%). Is the amount of change in the flow rate per unit time obtained by calculation from the difference between the previous integrated value and the current integrated value. For example, in the example shown in FIG.
The quantity shown in Q3 corresponds to this. Note that FIG. 4 shows the average flow rate per unit time based on the integrated flow rate value for each fixed time τ and represents the average flow rate per time τ, and does not represent the real time change of the flow rate. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the average flow rate for each time τ.

In FIG. 3, the continuous usable time is the time during which continuous gas use is permitted, and the length is set to a different value according to the magnitude of the individual flow rate. More specifically, when the gas is continuously used so as not to exceed a predetermined flow rate fluctuation range (for example, 3% or less), the flow path is shut off when the corresponding individual flow rate in FIG. 3 is reached. Is the continuous usable time.
In the example shown in FIG. 3, the range of the individual flow rate is a range in which the maximum flow rate value (liter / hour) determined by the number of the meter is an upper limit, and is 0 to 50 liter / hour and 50 to 500 liter.
L / h, 500-1000 l / h, 100
It is classified into six types: 0 to 2000 liters / hour, 2000 to 3000 liters / hour, and 3000 to the maximum flow rate value liters / hour according to the number of meters. The continuous usable time is, for example, corresponding to the range of these individual flow rates,
Unlimited time, 720 minutes, 360 minutes, 120 respectively
Minutes, 60 minutes and 30 minutes. Here, the continuous usable time table 161b corresponds to the “continuous usable time table” in the present invention.

The timer 161c is for measuring the elapsed time (gas use time) starting from the time of the change when a certain individual flow rate is changed to another individual flow rate. Is reset by the start signal, and the timer operation is started.

FIG. 5 shows a sectional structure of the weighing mechanism section 100 shown in FIG. This weighing mechanism section 100
Inlet 11 for receiving gas and outlet 1 for discharging gas
2 is provided. A partition 13 is provided in the main body 10, a first gas flow path 14 is formed between the partition 13 and the inlet 11, and the partition 13 and the outlet 12
A second gas flow path 15 is formed between the second gas flow path and the second gas flow path. Partition wall 1
An opening 16 is provided in 3, and the above-described shutoff valve 140 (FIG. 1) is provided in the first gas channel 14 so as to close the opening 16. A valve driving unit 150 (FIG. 1) made of a solenoid or the like is fixed to the outside of the main body 10,
The plunger 19 of the valve driving section 150 penetrates the side wall of the main body 10 and is connected to the shutoff valve 140. A spring 20 is provided around the plunger 19 between the shutoff valve 140 and the main body 10, and the spring 20 urges the shutoff valve 140 toward the opening 16. During normal use, the solenoid of the valve drive unit 150 is kept energized, and the shutoff valve 140 is separated from the opening 16.

In the second gas passage 15, there is provided a nozzle 21 for passing the gas received from the inlet 11 to generate a jet. A rectifying member 22 for adjusting the flow of gas is provided upstream of the nozzle 21. Downstream of the nozzle 21, a pair of side walls 23 and 24 that form an enlarged flow path are provided. This side wall 2
A predetermined interval is left between 3, 24, and the first
A target 25 and a second target 26 are provided on the downstream side, respectively. In addition, outside the side walls 23 and 24,
A return guide 2 that forms a pair of feedback flow paths 27 and 28 that return the gas that has passed through the nozzle 21 to the ejection port side of the nozzle 21 along the outer peripheral portions of the side walls 23 and 24.
9 are provided. Also, the feedback channel 27,
28, a pair of discharge paths 3 is provided between the outlet portion 12 and the outlet portion 12 by the back surface of the return guide 29 and the main body 10.
1, 32 are formed. In the vicinity of the ejection port of the nozzle 21, pressure guiding holes 33 and 34 are provided to communicate with a piezoelectric film sensor for detecting a change in the direction of flow of the gas passing through the nozzle 21.

The flow sensor 1 is provided in the passage of the nozzle 21.
02 is provided. The flow sensor 102 is configured as, for example, a thermal flow sensor having a heat generating portion and two temperature sensors disposed before and after the heat generating portion.

FIG. 6 is an enlarged cross-sectional view of the main body 10 including the pressure guiding holes 33 and 34 in FIG. As shown in this figure, a piezoelectric film sensor 101 is provided outside the bottom of the main body 10. Further, one ends of pressure guiding tubes 51 and 52 are connected to the pressure guiding holes 33 and 34, respectively. The other end of each of the pressure guiding tubes 51 and 52 is connected to each pressure inlet of the piezoelectric film sensor 101. Then, by the piezoelectric film sensor 101, the pressure guiding holes 33 and the pressure guiding holes 3 are formed.
4, the fluid pressure oscillation is detected based on the change in the pressure difference. In addition,
The pressure guiding tubes 51 and 52 and the piezoelectric film sensor 101 are
0 is covered by a case 55 fixed to the outside of the bottom.

Next, with reference to FIGS. 7 and 8, a method of transmitting and receiving the signal S1 indicating the use state of the gas appliance 110 between the gas appliance 110 and the gas meter will be described.
Here, a method in which the gas appliance 110 and the gas meter are electrically connected by wire to transmit and receive the signal S1 will be described. FIG. 7 shows a so-called contact output type system. In this method, the gas appliance 110 side is the gas appliance 1
A switch SW which is turned on / off in accordance with use of the switch 10;
Terminals 211 and 21 connected to both ends of this switch SW
2 is provided. On the other hand, on the gas meter side, the signal receiving unit 164 has a common (IN) terminal 213 connected to the terminal 211 of the gas appliance 110 and a common terminal connected to the terminal 212 of the gas appliance 110 via the DC power supply 215. (CO
M) terminal 214 is provided. In this method, a voltage is constantly applied from the DC power supply 215 on the gas meter side. When the gas appliance 110 is not used, the switch SW is turned off, and when the gas appliance 110 is used, the switch SW is turned on. On the gas meter side, a voltage change when the switch SW is turned on is detected as a signal S1.

FIG. 8 shows a so-called voltage output type system. In this method, the gas appliance 110 side includes a resistor R,
It includes a transistor Tr and terminals 221, 222 and 223. The terminal 221 is connected to one end of the resistor R and a power supply 226. The other end of the resistor R is connected to the collector terminal of the transistor Tr. The collector terminal of the transistor Tr is also connected to the output terminal 222. The emitter terminal of the transistor Tr is connected to the terminal 223. Terminal 223
Are also connected to a power supply 226. On the other hand, on the gas meter side, an input (IN) terminal 224 connected to the output terminal 222 on the gas appliance 110 side is connected to the signal receiving unit 164.
And a common (COM) terminal 225 connected to the power supply 226 and the terminal 221 on the gas appliance 110 side. In this method, when the gas appliance 110 is off when not in use, the output signal from the output terminal 222 of the gas appliance 110 is off. On the other hand, when the gas appliance 110 is in the ON state in the use state, the output signal from the output terminal 222 of the gas appliance 110 is sent to the input terminal 224 on the gas meter side by the signal S1.
Is entered as The signal receiving section 164 on the gas meter side detects this signal S1.

It should be noted that the gas equipment 11 is
An identification signal indicating the type of 0 may be transmitted at the same time, and the type of the gas appliance 110 may be identified on the gas meter side. By identifying the type of the gas appliance 110, for example, when there are a plurality of gas appliances 110, the gas appliance 11
It is possible to set the continuous usable time according to the type of 0. In this case, as the identification signal indicating the type of the gas appliance 110, for example, there is a method of outputting a different pulse signal for each gas appliance according to the type of the gas appliance 110. For example, TES (Th
When using a gas hot water heating / cooling system (trademark of Tokyo Gas Co., Ltd.) or a gas heat pump, a pulse signal is output from the gas equipment by TES at ON / OFF intervals of 1 second each. Then, a pulse signal is output from the gas heat pump with an ON period of 2 seconds and an OFF period of 1 second. On the gas meter side, a plurality of gas appliances 110 can be identified according to the difference between the pulse signals. Note that the method of outputting the pulse signal is not limited to this. In addition, a plurality of signal receiving units 167 are provided on the gas meter side, and a plurality of gas appliances 11 are provided.
The identification of each gas appliance 110 may be performed by receiving a signal for each gas appliance transmitted from 0.

Next, the operation of the gas meter configured as described above will be described.

First, the operation of the gas meter for measuring and displaying the flow rate will be described. In FIG. 5, the weighing mechanism 1
The gas received from the inlet 11 of the first nozzle 00 passes through the first gas flow path 14, the opening 16, the second gas flow path 15, and the rectifying member 22 in this order, and enters the nozzle 21. The gas that has passed through the nozzle 21 is jetted from the jet port as a jet. The gas ejected from the ejection port flows along one side wall due to the Coanda effect. Here, it is assumed that the flow first flows along the side wall 23. The gas flowing along the side wall 23 is further returned to the ejection port side of the nozzle 21 through the feedback channel 27 and is discharged from the outlet section 12 through the discharge path 31. At this time, the direction of the gas ejected from the nozzle 21 is changed by the gas flowing through the feedback flow path 27, and the gas flows along the other side wall 24 this time. This gas is further returned to the ejection port side of the nozzle 21 through the feedback channel 28 and discharged from the outlet section 12 through the discharge channel 32. Then, the direction of the gas ejected from the nozzle 21 is changed by the gas flowing through the feedback channel 28, and the side wall 2
3. Flow along the feedback flow path 27. By repeating the above operation, the gas that has passed through the nozzle 21 performs fluidic oscillation that alternately flows through the pair of feedback channels 27 and 28. The frequency and period of this fluid oscillation have a correspondence with the flow rate,
Detected by the piezoelectric film sensor 101 (FIG. 6) and output as a flow rate signal, the flow rate calculation unit 162 of the control unit 160
(FIG. 1).

On the other hand, the flow sensor 102 generates a temperature difference between two temperature sensors (not shown) according to the flow rate of the gas flowing through the heating section (not shown) when the heating section (not shown) is heated with a constant current or constant power. Is output as a flow rate signal and input to the flow rate calculation unit 162.

In FIG. 1, when the flow rate is in a large flow rate range suitable for measurement by a fluidic element, a flow rate calculation unit 162 uses a flow rate signal from the piezoelectric film sensor 101 and the flow rate is suitable for measurement by the flow sensor 102. When the flow rate is in the small flow rate range, the flow rate is calculated using the flow rate signal from the flow sensor 102. Specifically, when using the piezoelectric film sensor 101, the flow rate calculation unit 162
A pulse is generated based on the flow rate signal from the controller, the number of pulses per unit time is counted, a frequency of the fluidic oscillation is obtained, and this frequency is converted into a flow rate. On the other hand, when the flow sensor 102 is used, the number of pulses per unit time of the flow signal from the flow sensor 102 is counted to determine the flow rate. When the flow rate is in a region where the large flow rate area and the small flow rate area intersect, the flow rate calculation unit 162 may calculate the flow rate from one of the outputs,
The flow rate may be obtained by an operation (for example, taking an average value) using both outputs. Or Japanese Unexamined Patent Publication
As described in JP-96817-A, the piezoelectric film sensor 1
Flow sensor 1 based on the measured value from the output from
02 may be calibrated.

The flow value 166 obtained by the flow calculating section 162 is sent to the integrating section 163 and also to the valve opening / closing control section 161. The integrating section 163 integrates the flow value 166 to obtain a flow integrated value, and displays the integrated value on the display 12.
Send to 0 for display. On the other hand, the valve opening / closing control unit 161
In addition to checking the value of the input flow rate value 166, the presence or absence of the input of the detection signal 167 from the signal receiving unit 164 is checked, and according to the result, it is determined whether or not the gas valve is shut off by the shutoff valve 140. Do.

Next, with reference to FIG. 9, the operation of the gas meter for shutting off the flow path will be described. The following description also serves as a description of the gas leak detection method according to the present embodiment.

FIG. 9 mainly shows the operation of the determination section 161a (FIG. 2) in the valve opening / closing control section 161.
The determination unit 161a of the valve opening / closing control unit 161 checks the flow value 16 from the flow rate calculation unit 162 in order to check the usage state of the gas.
6 is constantly monitored to determine, for example, whether there is a change in the flow rate of 3% or more (step S101). If there is no change in the flow rate of 3% or more (N), this determination is repeated. When there is a change in the flow rate of 3% or more (step S10)
1; Y) calculates the individual flow rate next (step S1).
02). As described with reference to FIG. 4, the calculation of the individual flow rate is performed for a predetermined time τ of the flow rate value 166 from the flow rate calculation unit 162.
When the integrated value of each unit changes beyond a certain range (here, 3%), a change in the average flow rate per unit time is obtained from the difference between the previous integrated value and the current integrated value. For example, when the use of gas is started, ΔQ1 in FIG. 4 is the individual flow rate.

Next, the judgment section 161a outputs the detection signal 167
It is determined whether or not the signal S1 is detected by the signal receiving unit 164 based on (step S103). Judgment unit 1
When the signal S1 is not detected (step S103; N), the reference numeral 61a refers to the continuous usable time table 161b (FIG. 3) to determine the continuous usable time T corresponding to the calculated individual flow rate. Acquire and timer 1
A start signal is sent to the timer 61c, the timer 161c is reset, and the timer operation is started (step S10).
4).

After that, based on the flow rate value 166 from the flow rate calculation section 162, the determination section 161a determines whether the integrated value of the flow rate value 166 for each fixed time τ has changed by a certain range (here, 3%) or more. Is monitored (step S10).
Along with 5), it is monitored whether or not the gas usage time has exceeded the continuous usable time T based on the time count value from the timer 161c (step S106). Here, when the state where the integrated value of the flow rate value 166 for each fixed time τ is within a certain range (here, 3%) continues over the above-mentioned continuous usable time T (step S105; N, step S106; Y). The determination unit 161a determines that the individual flow rate is not due to the use of the gas appliance 110 but to the occurrence of an abnormality such as gas leakage, and outputs the valve drive signal 165 to the valve drive unit 150 to drive the shutoff valve 140. And
The gas flow path is shut off (Step S107). On the other hand, when the integrated value of the flow rate value 166 for each certain time τ exceeds the above-mentioned certain range (Step S105; Y), Step S1
Returning to step S103, the individual flow rate is calculated again.
The following processing is performed.

For example, in FIG. 4, assuming that the individual flow rate ΔQ1 at the beginning t1 of the gas use is, for example, 800 liters / hour, the continuous use time T is reduced to 360 minutes by referring to the continuous use time table 161b. At the same time, the timer 161c is reset and the timer operation is started (step S104), and the time-up of the continuous usable time of 360 minutes is monitored (steps S105 and S106). Further, assuming that the flow rate subsequently changes and the individual flow rate ΔQ2 at time t2 is, for example, 400 liters / hour, the continuous usable time T is 720
The timer is set to minutes and the timer 161c is reset to resume the timekeeping operation, and the continuous usable time of 720 minutes is monitored. In these cases,
When the continuous use time T has elapsed, the gas flow path is shut off by the shutoff valve 140 (step S107).

On the other hand, when the signal receiving section 164 detects the signal S1 indicating the use state of the gas appliance 110 (step S103; Y), the judging section 161a judges that the change in the flow rate indicates that the gas appliance 110 is in use. It is determined that there is (Step S108), and the continuous usable time table 16
At step S109, the start signal is sent to the timer 161c, and the timer 161c is changed.
Is reset to start the timekeeping operation, and thereafter, the process returns to step S101 and subsequent steps.

Here, as a method of extending the continuous usable time, there are, for example, the following four methods, and any of these methods may be used. As a first method, the continuous usable time T is set to be unlimited regardless of the value of the individual flow rate. As a second method, a usable time of, for example, about several hours is uniformly added to all the continuous usable times for each individual flow rate range in the continuous usable time table 161b. As a third method, for example, a different usable time of about several hours is added to each individual flow rate range according to each individual flow rate range in the continuous available time table 161b.

As a fourth method, the continuous usable time table 16 used when the signal S1 is not detected is used.
Use another table different from 1b (first continuous usable time table). The other table used here is, for example, a table in which the continuous usable time for each individual flow rate range is set longer than the continuous usable time table 161b. This table is used for the gas equipment 1
A plurality of tables corresponding to the ten types may be prepared, or a single table common to the different types of gas appliances 110 may be prepared. When using a plurality of tables according to the type of the gas equipment 110, for example, the gas equipment 11
An identification signal indicating the type of the gas appliance 110 is simultaneously transmitted from the 0 side, the type of the gas appliance 110 is identified on the gas meter side, and a table corresponding to the identified gas appliance 110 is used. In this case, as the identification signal indicating the type of the gas appliance 110, for example, a different pulse signal is output for each gas appliance according to the type of the gas appliance 110. For example, when a TES or a gas heat pump is used as the plurality of gas appliances 110, a pulse signal is output from the gas appliance using the TES at ON / OFF intervals of 1 second each, and the gas heat pump is turned ON for a period of time. Is 2 seconds, and a pulse signal whose off period is 1 second is output. On the gas meter side, the plurality of gas appliances 110 are identified according to the difference between the pulse signals. Alternatively, a plurality of signal receiving units 167 may be provided on the gas meter side, and identification of each gas appliance 110 may be performed by receiving signals for each gas appliance transmitted from the plurality of gas appliances 110.

In the above-described second to fourth methods,
When the state where the integrated value of the flow rate value 166 for each fixed time τ is within a fixed range (for example, 3%) continues over the extended continuous usable time T, the determination unit 161a
However, it is preferable that the shutoff valve 140 be driven by outputting the valve drive signal 165 to the valve drive unit 150 to shut off the gas flow path.

As described above, according to the present embodiment, the gas meter detects the flow rate of the gas flowing through the gas flow path, receives the signal S1 indicating the use state of the gas appliance 110, and receives the signal S1. The use state of the gas device 110 is determined based on the detected signal S1 and the detected gas flow rate, and it is determined whether or not there is a leak in the gas flow path. It is possible to determine whether or not gas is leaking, and it is possible to appropriately detect gas leakage according to the usage state of the gas appliance. Therefore, it is possible to shut off the gas flow path only when the gas equipment 110 is not used. That is, even when using a gas appliance 110 that may perform proportional control of the combustion amount within a certain range (within 3%), such as a hot water circulation floor heating system or a gas heat pump, the detected flow rate Can be discriminated whether it is due to the use of the gas appliance 110 or due to gas leakage. Accordingly, the proportional control type gas equipment 110
Can prevent the gas flow path from being accidentally shut off when used for a long time. Further, even when the gas appliance 110 having no function of transmitting the signal S1 indicating the use state is used, the gas flow is determined by using the continuous available time table 161b and the gas flow path is shut off.
Safety is better than before.

According to the present embodiment, the gas appliance 1
In addition to preparing a plurality of continuous use time tables corresponding to the ten types,
The identification signal indicating the type of the gas appliance 110 is transmitted at the same time, and the type of the gas appliance 110 is identified on the gas meter side. Since the determination can be performed, the use state can be determined for each type of the gas appliance 110, and the gas leak can be more appropriately detected according to the type of the gas appliance 110. .

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the gas meter using both the flow signal obtained from the piezoelectric film sensor 101 for detecting the fluidic oscillation of the fluidic element and the flow signal obtained from the flow sensor 102 has been described. The present invention is not limited to this, and can be applied to, for example, a device using only a fluidic element or a device using only the flow sensor 102. Further, the present invention can be applied to a gas meter using another type of flow meter such as a membrane flow meter.

[0063]

As described above, claims 1 to 7 are described.
According to the gas meter according to any one of the above, the gas leak detection system according to claim 8, or the gas leak detection method according to claim 9, the flow rate of the gas flowing through the gas flow path is detected, and the usage state of the gas appliance is determined. Signal, and based on the received signal and the detected gas flow rate, determine the use state of the gas appliance and determine whether there is a leak in the gas flow path. Therefore, it is possible to determine whether the gas appliance is used or not, and it is possible to appropriately detect a gas leak according to the usage state of the gas appliance. Therefore, for example, even when the combustion amount control is performed in a range that is considered to be almost constant in a proportional control type gas appliance,
Whether the detected gas flow rate is due to gas combustion,
Alternatively, it is possible to discriminate whether the cause is gas leakage.
As a result, it is possible to eliminate the problem that the gas flow path is erroneously shut off when the proportional control type gas device is used for a long time as in the related art.

In particular, according to the gas meter of the sixth aspect, in the gas meter of the third aspect, the judging means comprises:
Based on the received signal received by the receiving means, the type of the gas appliance being used is identified, and when it is determined that the gas appliance is being used, the first continuous usable time table is displayed. On the other hand, the usable time corresponding to the gas flow rate is obtained by referring to the second continuous usable time table for each type of the gas equipment in which the continuous usable time is extended, and the change amount of the gas flow rate is obtained. Since it is determined that there is a leak in the gas flow path on condition that the gas flow path is within a predetermined range over the usable time, it is possible to determine the use state for each type of gas equipment and to determine whether the gas is used. This has the effect that gas leaks can be detected more appropriately according to the type of equipment.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a gas leak detection system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a valve opening / closing control unit in the gas meter illustrated in FIG.

FIG. 3 is a diagram illustrating an example of a continuously usable time table in a valve opening / closing control section illustrated in FIG. 2;

FIG. 4 is a timing chart for explaining the operation of the gas meter shown in FIG.

FIG. 5 is a cross-sectional view illustrating a main structure of a metering mechanism in the gas meter illustrated in FIG.

FIG. 6 is an enlarged cross-sectional view illustrating a main structure of a metering mechanism in the gas meter illustrated in FIG.

FIG. 7 shows a gas leak detection system shown in FIG.
FIG. 4 is an explanatory diagram illustrating an example of a method of transmitting and receiving a signal indicating a usage state of a gas appliance.

FIG. 8 shows a gas leak detection system shown in FIG.
It is explanatory drawing showing another example of the method of transmitting and receiving the signal showing the use condition of gas equipment.

FIG. 9 is a flowchart for explaining the operation of the gas meter shown in FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Metering mechanism unit 101 Piezoelectric film sensor 102 Flow sensor 110 Gas device 140 Shut-off valve 150 Valve drive unit 160 Control unit 161 Valve open / close control unit 161a Judgment unit 161b Continuous usable time table 161c Timer 162 Flow rate calculation unit 164 Signal reception unit 167 Detection signal

Claims (9)

[Claims] 1. A flow rate detecting means for detecting a flow rate of a gas flowing through a gas flow path, a receiving means for receiving a signal indicating a use state of a gas appliance, a reception signal received by the receiving means and the flow rate detecting means A gas meter comprising: a determination unit configured to determine a use state of the gas appliance based on a gas flow rate detected by the determination unit and determine whether there is a leak point in the gas flow path. . 2. The receiving means has a plurality of signal receiving units for receiving signals for each gas appliance transmitted from the plurality of gas appliances, and the determining unit receives the signals by the plurality of signal receiving units. 2. The gas meter according to claim 1, wherein the use state of each gas appliance is determined based on the received signal of each gas appliance and the gas flow rate detected by the flow rate detection means. 3. The apparatus according to claim 1, further comprising at least one continuously usable time table in which a gas flow rate is associated with a continuously usable time indicating a time during which the gas can be used continuously. When it is determined that the gas appliance is not used, the available time corresponding to the gas flow rate is obtained by referring to the first continuous available time table, and the change amount of the gas flow rate is obtained. The gas meter according to claim 1, further comprising a function of determining that there is a leak in the gas flow path on condition that the gas flow path is within a predetermined range over an available time. 4. The method according to claim 1, wherein the determining unit determines that the gas appliance is in use by extending the first usable time in the first continuously usable time table. 4. The gas meter according to claim 3, wherein the continuous use time table is changed to determine whether or not there is a leak in the gas flow path. 5. When the gas device is determined to be in use, the determining means determines that the continuous use time has been extended with respect to the first continuous use time table. The usable time corresponding to the gas flow rate is obtained by referring to the usable time table, and the gas flow rate leaks into the gas flow path on the condition that the change amount of the gas flow rate is within a predetermined range over the obtained usable time. The gas meter according to claim 3, wherein it is determined that there is a location. 6. The method according to claim 1, wherein the determining unit identifies a type of the gas appliance being used based on a reception signal received by the receiving unit and determines that the gas appliance is used. Refers to a second continuous available time table for each type of gas equipment in which the continuous available time is extended with respect to the first continuous available time table, and refers to an available time corresponding to the gas flow rate. And determining that there is a leak in the gas flow path on condition that the amount of change in gas flow rate is within a predetermined range over the obtained usable time. Gas meter. 7. The apparatus according to claim 1, further comprising a flow path shutoff means for shutting off the gas flow path when the determination means determines that there is a leak in the gas flow path. The gas meter according to 1, 2, 3, 4, 5, or 6. 8. A gas leak detection system for detecting a gas leak in a gas flow path connected to a gas device on a downstream side, wherein the gas device transmits a signal indicating a use state to the gas meter. Means, a flow rate detecting means for detecting a flow rate of gas flowing through the gas flow path, a receiving means for receiving a signal indicating a use state of the gas equipment, a receiving signal received by the receiving means And determining means for determining the use state of the gas appliance based on the gas flow rate detected by the flow rate detecting means and determining whether or not there is a leak in the gas flow path. A gas leak detection system characterized by the following. 9. A method for detecting a flow rate of a gas flowing through a gas flow path, receiving a signal indicating a use state of a gas device, and detecting a use state of the gas device based on the received signal and the detected gas flow rate. And a determination as to whether or not there is a leak in the gas flow path.