JPH079065Y2 - Gas leak monitoring device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of use] The present invention relates to a gas leakage monitoring device for monitoring gas leakage generated from a gas pipe or the like, and more specifically to a gas pressure regulator for gas from an LP gas cylinder. And a gas leakage monitoring device for monitoring gas leakage in an LP gas supply system supplied through a gas meter.

[Conventional technology]

Generally, the LP gas supply system has a structure as shown in FIG.

In the figure, two gas cylinders 1 ₁ and 1 ₂ are connected to a gas pressure regulator ₂ having an automatic switching function, and the gas is discharged from one of the gas cylinders 1 ₁ or 1 ₂ through the gas pressure regulator 2. The gas discharged from the gas cylinder is supplied to the gas meter 4 through the gas pipe 3 on the primary side (upstream side), and from there is further discharged to the gas stopper 6 at the end through the gas pipe 5 on the secondary side (downstream side). . Thus, the gas pressure regulator 2 switching function by the gas derived from the gas cylinder 1 ₁ or 1 ₂ selected one is supplied to the gas meter 4 through the gas pipe 3, further led to the gas valve 6 through the gas pipe 5 Then, the gas is consumed by a gas combustor (not shown) connected to the gas plug 6.

When the gas consumption of one of the gas cylinders selected by the switching function of the gas pressure adjuster 2, for example, ₁₁ (supply gas cylinder) progresses, and the remaining amount of the gas decreases, the internal pressure of the cylinder decreases and the gas combustor needs it. It becomes impossible to supply a gas at a proper pressure. Therefore, the gas pressure regulator 2 with automatic switching function, aims to automatically open the gas introduction and the other of the gas cylinder 1 ₂ opening introduction (supply gas cylinder) is connected by its auto-switching capabilities, causing gas shortage Without fail, the gas of the required pressure can be reliably supplied.

In the gas supply system as described above, the gas meter is provided with a flow rate sensor, the flow rate sensor monitors the supply gas flow rate based on a flow rate pulse generated in response to a constant amount of gas supply, and the flow rate exceeds the maximum usage amount. It is determined whether there is a large amount of gas leakage on the secondary side downstream of the gas meter by judging whether there is a gas flow rate, or whether there is a gas flow rate of 3 l / hour or more for a predetermined time such as 30 days continuously. What detects a minute leak on the downstream side of the downstream side, and activates an alarm device installed in the room in response to the detection to generate an alarm, or to notify the gas distribution company. Already proposed.

[Problems to be solved by the device]

However, in the conventional gas leak monitoring device described above, the gas leak is monitored on the downstream side of the gas meter, and the gas leak on the gas pipe or the gas pressure regulator on the primary side upstream of the gas meter is monitored. Since it was not possible to monitor it, it was hard to say that they are doing sufficient monitoring.

Therefore, in view of the above conventional problems, it is an object of the present invention to provide a gas leakage monitoring device capable of sufficiently monitoring gas leakage on the primary side upstream of a gas meter.

[Means for Solving the Problems]

In order to solve the above problems, the gas leakage monitoring device according to the present invention supplies the gas from the LP gas cylinders 11 ₁ and 11 ₂ through the gas pressure regulator 12 and the gas meter 13 as shown in the basic configuration diagram of FIG. In the LP gas supply system to
Flow rate measuring means 14-1 for counting the flow rate signal generated each time a predetermined flow rate of gas is supplied through the gas meter to measure the flow rate of the gas supplied through the gas meter.
And a remaining amount measuring means 111 for measuring the remaining amount of gas in the LP gas cylinder, and a time measuring means 14-2 for repeatedly measuring a predetermined period.
And a gas residual amount storage means 14b-1 for storing the gas residual amount value of the LP gas cylinder measured by the residual amount measuring means at the start of a predetermined period timed by the time measuring means, and stored in the storage means. The difference between the remaining gas amount value and the remaining gas amount value of the LP gas cylinder measured by the remaining amount measuring means at the end of the predetermined period timed by the time measuring means A remaining amount change amount detection means 14-3 for obtaining a change amount, and a flow rate measurement value storage means 14 for storing the flow rate measurement value of the gas measured by the flow rate measurement means at the start of a predetermined period timed by the time measurement means.
b-2 and the difference between the flow rate measurement value stored in the flow rate measurement value storage means and the flow rate measurement value of the gas measured by the flow rate measurement means at the end of the predetermined period timed by the time measurement means The flow rate change amount detecting means 14-4 for obtaining the change amount of the flow rate measured value within the period, and the change amount of the gas remaining amount value obtained by the remaining amount change amount detecting means is the flow rate obtained by the flow amount change amount detecting means. When the amount of change in the measured value is larger than a predetermined value by a predetermined value or more, a determining means 14-5 for determining that there is a gas leak between the LP gas cylinder and the gas meter is provided.

[Action]

In the above configuration, the flow rate measuring means 14-1 measures the flow rate of the gas supplied through the gas meter by counting the flow rate signal generated each time a predetermined flow rate of gas is supplied through the gas meter 13, and the residual quantity measuring means. 111 weighs the amount of gas remaining in the LP gas cylinder. The gas residual amount value of the LP gas cylinder measured by the residual amount measuring device at the start of a predetermined period repeatedly measured by the time measuring device 14-2 is stored in the gas residual amount storage device 14b-1, and the stored gas residual amount is stored. The remaining amount change amount detecting means 14-3 determines the remaining gas amount within the predetermined period by the difference between the amount value and the remaining gas amount value of the LP gas cylinder measured by the remaining amount measuring means at the end of the predetermined period timed by the time measuring means. Find the amount of change in the value.

The flow rate measurement value of the gas measured by the flow rate measurement means is stored in the flow rate measurement value storage means 14b-2 at the start of a predetermined period timed by the time measurement means, and the stored flow rate measurement value and the time measurement means are timed. At the end of the predetermined period, the flow rate change amount detecting means 14-4 obtains the change amount of the flow rate measured value within the predetermined period based on the difference from the flow rate measured value of the gas measured by the flow rate measuring means. When the amount of change in the remaining gas amount value obtained by the remaining amount change amount detecting means is larger than the amount of change in the flow rate measured value obtained by the flow amount change amount detecting means by a predetermined value or more,
The judging means 14-5 judges that there is a gas leak between the LP gas cylinder and the gas meter.

As described above, it has the flow rate measured value storage means 14b-2, and stores the flow rate measured value of the gas measured by the flow rate measuring means at the start of a predetermined period in which the time measuring means 14-2 repeatedly measures time,
The stored flow rate measurement value is used to determine the amount of change in the flow rate measurement value within the predetermined period at the end of the predetermined period, that is, the gas supply amount to the gas meter downstream side, and the remaining gas amount value storage means 14b- 1 and stores the gas residual quantity value of the LP gas cylinder measured by the residual quantity measuring means at the start of a predetermined period in which the time measuring means 14-2 repeatedly measures time, and uses the stored gas residual quantity value. At the end of the predetermined period, the change amount of the gas leakage value within the predetermined period, that is, the gas supply amount from the LP gas cylinder is obtained, and when the change amount of the remaining gas value is larger than the change amount of the flow rate measured value by a predetermined value or more, the gas leakage I try to judge that there is.

Therefore, the flow rate measuring means 14-1 counts the flow rate signal generated by the gas meter 13 every time the gas having a predetermined flow rate is supplied,
Even if the flow rate cannot be measured with a resolution equal to or higher than the unit flow rate and the gas leakage is small, by extending the predetermined period determined by the timing by the timing means, By comparing the amount of change and the amount of change in the flow rate measured value, it is possible to determine gas leakage on the primary side upstream of the gas meter.

〔Example〕

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

FIG. 2 is a block diagram showing an embodiment of a gas leakage monitoring device according to the present invention. In FIG. 2, 11 ₁ is a gas cylinder for supply, 11 ₂ is a gas cylinder for supply 1 ₂ and 12 is these gas cylinders 11. ₁ and 11 ₂ the gas pressure regulator 12 and 13 with an automatic switching function is connected is supplied with a gas whose pressure is adjusted by the gas pressure regulator 12, a gas meter for measuring the flow rate of the feed gas, the gas meter 13 Is a flow rate sensor 13a that generates one pulse that is a flow rate signal according to a predetermined flow rate.
Built in.

As the gas cylinder 11 _1, 11 _2, to use those for example to detect the liquid level of the liquefied gas in the gas cylinder, as shown in FIG. 3, a built-in level detecting unit 111 for outputting a remaining gas amount signal. More specifically, the remaining amount detecting device 111 includes a guide rod 111a provided in the gas cylinder along the liquid level changing direction.
A magnetic sensing element (not shown) provided along the longitudinal direction of the guide rod 111a, a flood 111b guided along the guide rod 111a, and a magnet (not shown) attached to the float 111b. By moving the float 111b up and down according to the liquid level of the gas, a remaining amount signal according to the liquid level is output.

Further, the gas pressure regulator 12 and the gas meter 13 are integrated side by side as shown in FIG. 3, and the gas outlet of the gas pressure regulator 12 is directly connected to the gas meter 13 without any piping.
It is configured to be connected to the gas inlet of. Note that 13b
Is a pipe connected to the gas outlet of the gas meter 13, 13c is a measurement display unit, and 13d is a remaining amount display unit that displays the remaining amount of gas in each gas cylinder.

Inside the gas pressure regulator 12, as will be described later with reference to FIGS. 4 and 5, the cylinders are switched on and off alternately, that is, switches SWI and SWII indicating the supply gas cylinder and the reinforcement gas cylinder are turned off. Therefore, a switch SWIII indicating the replenishment state is provided.

Reference numeral 14 is a remaining amount detection device 111 for each of the gas cylinders 11 ₁ and 11 ₂ , switches SWI to SWIII of the gas pressure regulator 11, and a flow rate sensor.
A microcomputer (CPU) connected to 12a
The CPU 14 stores data such as the result of processing according to the control program and the ROM 14a that stores the control program.
Having the RAM 14b, the gas consumption is measured based on the flow rate signal from the flow rate sensor 13a, and the change in the measured value within a predetermined time and the remaining amount signal from the remaining amount detection device 111 of the gas cylinder within a predetermined time. Of the gas leakage is detected, and the alarm device 15 is activated according to the result to generate an alarm, or the gas distribution company is notified through the network control unit (NCU) 16 and the telephone line 17. Or

A configuration example of the gas pressure regulator 11 having the automatic switching function will be described below with reference to the sectional views of FIGS. 4 and 5.

In the sectional views of FIGS. 4 and 5, only the housing is hatched, and hatching of other portions is omitted for simplicity. In the figure, a gas pressure regulator 12 with an automatic switching function includes a housing 123 having a pair of gas inlet ports 121 formed on both sides of one side and an outlet port 122 formed on the other side, and one side of an upper surface of the housing 123. And a regulating valve unit 125 arranged in parallel with the switching valve unit 124 above the housing 123.

Inside the housing 123, a high pressure gas primary pressure reducing chamber 126 connected to the switching valve unit 124 and a regulating valve unit 125.
To the gas secondary side decompression chamber 127, and both decompression chambers 126 and 12
It is composed of a gas flow path 128 that communicates between the seven.

The switching valve unit 124 and the adjusting valve unit 125 are housed in the recess 129a on one side and the recess 129b on the other side of the common cover 129.

The switching valve unit 124 is inside each inlet port 121 and has a valve element 130 that opens and closes a supply end of each inlet port 121,
A spring 131 that normally biases the valve body 130 toward the closing side, and a valve body 13
Plunger 132 that integrally projects at the upper part of 0, switching shaft 134 that integrates cam 133 that slidably contacts with each plunger 132, switching shaft 134 integrally project at the center, and the peripheral edge is recessed with the opening peripheral edge of housing 123. A diaphragm 135 that is sandwiched between the peripheral edges of the bottom surface of 129a and hermetically seals the inside of the primary-side decompression chamber 126, and is inserted between the upper part of the diaphragm 135 and the cover 129. Spring 136 that balances atmospheric pressure and gas pressure, and switching shaft 134
And a knob 137 for switching operation provided on the upper end of the protruding end from the cover 129.

An intermediate sleeve 138 is interposed between the switching shaft 134 and the knob 137. The intermediate sleeve 138 is rotatably supported at the upper center of the recess 129a and is coupled to the knob 137. A switching shaft 134 is held at the center of the intermediate sleeve 138 so as to be vertically slidable. A display body 139 is rotatably supported on the upper portion of the intermediate sleeve 138, and the display body 139 is a switching shaft.
The operation state of the switching shaft 134 is displayed through the display window 140 fitted in the central portion of the upper surface of the knob 137 so as to rotate in association with the lowering operation of the 134.

The spring 136 is set to be stronger than the spring strength of each spring 131, and in a normal state, each valve body 130 can be alternately opened and closed by switching operation of the knob 137. Then, when the primary pressure of the decompression chamber 126 becomes low, the diaphragm 135 bulges downward, the switching shaft 134 descends, and the display body 139 rotates, causing a change in color or other mechanical display through the display window 140. Accordingly, the depressurized state can be immediately determined.

The cam 133 has a disc shape, and a half of the circumference has a large diameter,
It also extends to the lower side and each plunger 13
A cam lead that slides on 2 is formed. In the figure, the cam lead surface presses one plunger 132, so that one valve body 130 is open and the other is closed.

As shown in FIG. 4, on the upper surface of the cover 129, the reed switches SWI and SWII corresponding to the two switching positions of the knob 137 are provided on the flange of the intermediate sleeve 138 which is rotated together with the knob 137. Magnets 141 are provided on 138a at positions facing the reed switch SWI or SWII when the knob 137 is rotated, and the switching state of the knob 137 can be known by the on / off states of the reed switches SWI and SWII.

Further, as shown in FIG. 3, a reed switch SWIII is provided in the recess 129a of the cover 129, and a magnet 142 is provided on the upper surface of the diaphragm 135 facing the reed switch SWIII. It is possible to detect that the diaphragm 135 has descended, and by this detection, it is possible to know that the valve body 130 on the gas inlet port 121 side, to which the supply gas cylinder is connected, is opened and supply is started.

To switch the gas cylinder that was a replenishment gas cylinder to the supply gas cylinder, turn knob 137 by 180 degrees.The cam lead surface of cam 133 comes off one plunger 132 and slides on the other plunger 132. Push down. This switching action closes one side and opens the other side.

The regulating valve unit 125 is sandwiched by the peripheral edge of the other recess 129b of the cover 129 and vertically and airtightly divides the secondary pressure reducing chamber 127 and the atmospheric pressure chamber into a pressure regulating diaphragm 145 and a diaphragm 145.
A spring 146 for urging the pressure reducing chamber 127 toward the pressure reducing chamber 127 side, and a pressure adjusting actuating rod 147 integrally provided at the center of the diaphragm 145.
, The lever 148 connected to the bottom of the operating rod 147, and the lever 14
The valve body 149 is slidably connected to the lower end of the valve 8, and the valve body 149 faces the nozzle 150 provided at the end of the gas flow path 128.

Therefore, the gas pressure in the secondary side decompression chamber 127 is reduced by the spring 146.
When the strength is higher than the strength of the diaphragm, that is, when the pressure is higher than a predetermined pressure, the diaphragm 145 bulges upward.
As a result, the operating rod 147 is pulled up, and the valve body 149 is moved to the closing side via the lever 148. When it becomes low, the reverse operation is performed. As a result, the secondary pressure reducing chamber 127 is always kept at a predetermined gas pressure.

In the above structure, when the residual gas in the supply gas cylinder is reduced and the gas is out of gas in a normal use state, the switching rod 134 is lowered and the other plunger 132 is also pushed down.
The display of the display body 139 rotated in response to this informs that replenishment from the replenishment gas cylinder is being performed.
Then, if the knob 137 is rotated 180 degrees from the current position in response to this display, the other gas inlet port 121 is opened, the supplementary gas cylinder is switched to the supply gas cylinder, and the newly connected gas cylinder is used as the supplementary gas cylinder. To do.

The outline of the operation of the gas leakage detection device described above will be described below.

In FIG. 2, when a gas having a predetermined flow rate is supplied to the combustor (not shown) through the gas meter 13, the flow rate sensor 13 a generates a flow rate pulse, which is input to the CPU 14. In response to this, the CPU 14 counts this pulse by the counter. Further, the CPU 14 monitors the remaining amount of each gas cylinder by the remaining amount signals from the gas cylinders 11 ₁ and 11 ₂ . Then, the change in the count value of the counter and the change in the gas remaining amount are compared at predetermined intervals, and as a result of this comparison, the change in the count value, that is, the gas consumption amount is the remaining amount change of the gas cylinder, that is, the gas supply amount from the gas cylinder When it is less than the predetermined value E by more than the predetermined value E, it is determined that there is a gas leak between the gas meter 14 and the gas cylinders 11 ₁ and 11 _2, and the alarm device 15 is activated to issue an alarm or NC
Notify the gas company through U16.

The details of the operation outlined above will be described below with reference to the flowchart of FIG. 6 showing the work performed by the CPU 14 in FIG.

The CPU 14 starts its operation when its power is turned on, and initializes in the first step S1. In this initialization, the flow rate measured value by the flow rate counter configured in the predetermined area of RAM14b in CPU14
It is stored in a register formed in another predetermined area in the RAM 14b as C ₀ , and the gas residual amount measurement value based on the residual amount signal from the gas cylinders 11 ₁ and 11 ₂ is stored as the initial gas residual amount measurement value K ₀₁ and K
_{As 02} , it is stored in a register formed in a predetermined area in the RAM 14b, and a timer that times out at a predetermined time is reset to start counting a predetermined time.

After that, the process proceeds to step S2, where it is determined whether or not a flow rate pulse is input from the flow rate sensor 13a.
When the determination is YES, the process proceeds to step S3, where the flow rate counter is counted up, and then the process proceeds to step S4. On the other hand, when the determination in step S2 is NO, that is, when the flow rate pulse is not input, step S3 is skipped and the process proceeds to step S4. In step S4, each gas cylinder 11 ₁ , 11
_The gas remaining amount measurement values K ₁ and K ₂ are respectively read by the remaining amount signal from the remaining amount detection device 111 of _2, and the read gas remaining amount measurement values K 1
Store ₁ and K ₂ in the corresponding registers. After that, the process proceeds to step S5, where it is determined whether or not the timer reset in step S1 has timed out,
When the determination is NO, the process returns to step S2.

The above steps S2 to S5 are repeatedly executed until the determination in step S5 becomes YES, and when the determination in step S5 becomes YES, that is, the time is over, the process proceeds to step S6. Step S6
, Switch SWIII that turns off when the supply starts
Is turned off, and if this determination is NO, that is, if replenishment has not started yet, the process proceeds to step S7.
In step S7, the switch that is turned on is the switch
Determine whether it is SWI or SWII. This determination is for determining which of the gas cylinders 11 ₁ and 11 ₂ is the supply gas cylinder by the knob 137 of the gas pressure regulator 13. Now, if the switch SWI is turned on and the gas cylinder 11 ₁ is the supply gas cylinder, step S
Proceed to step 8, where the difference between the gas residual quantity initial value K ₀₁ stored in the register by the initialization in step S1 above and the gas cylinder 11 ₁ gas residual quantity measured value K ₁ last read in and stored in the register at step S4 above. After obtaining ΔK, the process proceeds to step S9.

In step S9, the difference ΔC between the flow rate measurement initial value C ₀ stored in the register in step S1 and the flow rate measurement value C obtained by counting up the flow rate counter in step S3 is obtained, and then in step S10. move on. In step S10, ΔK obtained in step S8, that is, the amount of change in the remaining amount of gas in the gas cylinder 11 ₁ during the time-out time of the timer (the amount of gas supplied from the gas cylinder 11 ₁ )
And the difference E from the amount of gas actually supplied and consumed by the combustor through the gas meter 13 during the ΔC obtained in step S9, that is, the time-over time, is obtained in step S11.
Proceed to.

In step S11, ΔK obtained in step S10 above
It is determined whether −ΔC = E is larger than a predetermined value E ₀ . This determination is for determining whether or not the amount of gas supplied from the gas cylinder 11 ₁ is larger than the amount of gas measured by the gas meter 13 by a predetermined value or more, and gas leakage occurs between the gas cylinder 11 ₁ and the gas meter 13. However, the above value E ₀ eliminates erroneous judgment due to measurement error.

And when the gas supply amount from the amount of change i.e. the gas cylinder 11 ₁ of the gas remaining in the gas cylinder 11 ₁ enough to be determined that the determination in step S11 is YES, that gas has leaked often proceeds to step S12, where Activates the alarm device 15 to generate an alarm, or outputs an alarm signal for notifying the gas company to stop the operation.

When the determination in step S11 is NO, that is, when the supply amount from the gas cylinder 11 ₁ is not large enough to determine that gas leakage has occurred, the process proceeds to step S13. Step S13, resets the timer to restart the counting of the timer, followed by the gas cylinder 11 ₁ at step S14, 11 ₂ of the newest gas level metric K _1, K _2, respectively corresponding gas remaining weighed initially register The values K ₀₁ and K ₀₂ are stored, and the latest flow rate measurement value C is stored in the register as the flow rate measurement initial value C ₀ , and then the process returns to step S2.

In the above step S7, when the switch SWII is determined to be ON, i.e. gas cylinder 11 ₂ proceeds to step S15 when it is a supply gas cylinder, wherein the gas level metric initial value K ₀₂ and the latest gas remaining After obtaining the difference ΔK from the measured amount of gas K _{2, that} is, the amount of change in the remaining amount of gas in the gas cylinder 11 ₂ , the process proceeds to step S9 and thereafter, comparing the supply amount from the gas cylinder 11 ₂ with the measured flow rate in the gas meter 13. Monitor for gas leaks.

If the determination in step S6 is YES, that is, if gas replenishment is being performed, proceed to step S16, where (K
₀₁ -K ₁ ) + (K ₀₂ -K ₂ ) = ΔK, that is, both gas cylinders 11 ₁ and 11
Find the amount of change in the remaining gas amount of ₂ . Then, the presence or absence of leakage is monitored by comparing the supply amount from both the gas cylinders 11 ₁ and 112 ₂ and the flow rate at the gas meter 13 in the subsequent step S11.

By the operation described above, it becomes possible to reliably detect the gas leakage on the upstream primary side of the gas meter 13.

As is clear from the description of the processing flowchart of the CPU 14 performed with reference to FIG. 6, the CPU 14 counts the flow rate signal generated each time a predetermined flow rate of gas is supplied through the gas meter 13 by the processing of step S3. Flow rate measuring means 14-for measuring the flow rate of the gas supplied through the gas meter
It functions as 1. In addition, the CPU 14 functions as a time measuring unit 14-2 that repeatedly measures time for a predetermined period by the process of step S13. Furthermore, the CPU 14 uses the remaining gas amount value stored in the RAM 14b and the remaining amount detecting device 111 at the end of the predetermined period.
As a remaining amount change amount detecting means 14-3 for obtaining a change amount of the remaining gas amount value within a predetermined period based on a difference from the remaining gas amount value of the LP gas cylinder measured by the flow amount measurement value stored in the RAM 14b and a predetermined value. Flow rate change amount detecting means 14-4 for obtaining the amount of change in the flow rate measured value within a predetermined period based on the difference from the flow rate measured value of the gas measured by the flow rate measuring means 14-1 at the end of the period.
As the change amount of the remaining gas amount value obtained by the remaining amount change amount detecting means 14-3 is larger than the change amount of the flow rate measured value obtained by the flow amount change amount detecting means 14-4, the LP gas cylinder and the gas meter are It also functions as a determination means 14-5 for determining that there is a gas leak between them.

In the above-described embodiment, the means for measuring the remaining amount of gas in the gas cylinder is incorporated in the gas cylinder. However, as the remaining amount measuring device 111, as shown in FIG.
1 is a stand 111 incorporating a load detector or load cell 111c
The remaining amount may be measured by installing on the d and measuring the amount of gas in the gas cylinder 11 by the output signal of the load detector 111c according to the weight of the gas cylinder 11.

〔effect〕

As described above, according to the present invention, the flow rate measurement value of the gas measured at the start of the repeated predetermined period is stored, and the stored flow rate measurement value is used to determine whether the predetermined period is within the predetermined period at the end of the predetermined period. The amount of change in the flow rate measurement value, that is, the gas supply amount to the downstream side of the gas meter is calculated, the gas residual amount value of the LP gas cylinder measured at the start of the predetermined period is stored, and this stored gas residual amount value is used. At the end of the predetermined period, the amount of change in the residual gas amount within the prescribed period, that is, the amount of gas supplied from the LP gas cylinder is calculated, and the amount of change in the residual gas amount is greater than the amount of change in the flow rate measured value by a prescribed amount or more. Since it is determined that there is a gas leak, the gas leak on the primary side upstream of the gas meter can be determined.

Moreover, since the flow rate is measured by counting the flow rate signal generated by the gas meter each time the gas of a predetermined flow rate is supplied, the resolution of the flow rate measurement is not high, but the measured value at the beginning of the predetermined period is stored and stored. By extending the period, even if there is little gas leakage, it is possible to sufficiently monitor gas leakage by comparing the amount of change in the gas residual amount value with the amount of change in the flow rate measured value within a predetermined period. It has become.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a gas leakage monitoring device according to the present invention, FIG. 2 is a block diagram showing an embodiment of a gas leakage monitoring device according to the present invention, and FIG. 3 is a gas leakage monitoring device according to the present invention. Showing an example of the gas residual amount measuring means used in the above, FIG. 4 and FIG. 5 are sectional views showing an example of the constitution of the gas pressure regulator used in the gas leakage monitoring device according to the present invention, and FIG. FIG. 2 is a flow chart showing the work executed by the CPU in FIG. 2, FIG. 7 is a diagram showing another example of the gas remaining amount measuring means, and FIG. 8 is a diagram showing a configuration example of a conventional general LP gas supply system. is there. 11 ₁ , 11 ₂ ... LP gas cylinder, 12 ... pressure regulator, 13 ... gas meter, 111 ... residual amount measuring means (residual amount measuring device), 14-1 ...
Flow rate measuring means (CPU), 14-2 ... Time measuring means (CPU), 14-
3 ... Remaining amount change amount detecting means (CPU), 14-4 ... Flow rate change amount detecting means (CPU), 14-5 ... Judging means (CPU), 14b-1
... Gas residual amount storage means (RAM), 14b-2 ... Flow rate measured value storage means (RAM)

Claims (1)

[Scope of utility model registration request] 1. An LP gas supply system for supplying gas from an LP gas cylinder through a gas pressure regulator and a gas meter, wherein the gas meter counts a flow rate signal generated each time a gas having a predetermined flow rate is supplied through the gas meter. Flow rate measuring means for measuring the flow rate of the gas supplied through, the residual amount measuring means for measuring the remaining gas amount of the LP gas cylinder, the time measuring means for repeatedly measuring a predetermined period, and the predetermined period measured by the time measuring means. A gas residual amount storage means for storing the gas residual amount value of the LP gas cylinder measured by the residual amount measuring means at the start of, and the gas residual amount value stored in the storage means and the time measuring means. The remaining gas amount value within the predetermined period due to the difference from the remaining gas amount value of the LP gas cylinder measured by the remaining amount measuring means at the end of the predetermined period. A remaining amount change amount detecting means for obtaining a change amount, a flow rate measured value storage means for storing a flow rate measured value of the gas measured by the flow rate measuring means at the start of a predetermined period timed by the time measuring means, and the flow rate measured value. Change in the flow rate measured value within a predetermined period due to the difference between the flow rate measured value stored in the storage means and the flow rate measured value of the gas measured by the flow rate measuring means at the end of the predetermined period timed by the time measuring means Flow rate change amount detecting means for obtaining the amount, when the change amount of the gas remaining amount value obtained by the remaining amount change amount detecting means is larger than the change amount of the flow rate measured value obtained by the flow amount change amount detecting means by a predetermined value or more, A gas leak monitoring device, comprising: a determining unit that determines that there is a gas leak between the LP gas cylinder and the gas meter.