JP3421980B2 - Gas leak detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to liquefied propane (L
P) A gas leak detection device for detecting a leak in a gas supply pipe including a buried pipe of a gas supply facility, and in particular, the gas supply pipe supplies a large amount of gas to a plurality of consumers of an apartment house such as an apartment. The present invention relates to a gas leakage detection device suitable for a gas leak detection device.

[0002]

2. Description of the Related Art Conventionally, as a device of this type, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-41300, as shown in FIG. 11, switching applied to a gas supply facility for supplying gas to a housing complex such as a condominium, for example. Type gas leak detection devices have been proposed. In the figure, a gas supply source 1 such as an LP gas container and a gas intake of a condominium 2 are connected by a gas supply pipe 4, and the gas supply pipe 4 is provided with pressure regulators 5 and 6 and a gas meter 7. ing. A valve and a gas meter 8 (not shown) are provided in a pipe for supplying gas from a gas intake (not shown) to a gas consuming facility of each house of the condominium 2.

A parent pressure regulator 6 is provided on a gas supply pipe 4b between a primary regulator 5 on the side of the LP gas container 1 which is a gas supply source and a parent gas meter 7 for integrating the amount of gas supplied to the entire condominium 2. Further, the gas supply pipe 4b is provided with a bypass gas flow passage 14 that connects the inlet side and the outlet side of the parent pressure regulator 6. This bypass gas flow path 14
The inlet is provided with a child pressure regulator 15 and a microcomputer gas meter (hereinafter referred to as M meter) 16 as a minute leak detection means in order from the inlet side.

The adjusting pressure of the child pressure adjuster 15 is set higher than the adjusting pressure of the parent pressure adjuster 6. For example, when the adjusting pressure of the parent pressure adjuster 6 is set to 280 mmH ₂ O, the adjusting pressure of the child pressure adjuster 15 is about 300 mm.
Set to H ₂ O. Further, as the M meter 16, a minute flow rate, for example, a flow rate of about 3 liters / hour can be accurately integrated, and it is monitored by a minute leak detection function.
When there is a flow rate of 3 liters / hour or more for 30 consecutive days, it is judged that there is a leak, and the fact is displayed by lighting a lamp.

In the above structure, when the gas consumption at night or at midnight becomes almost zero, the pressure of the gas supply pipe 4b becomes high, the parent pressure regulator 6 is closed, and only the child pressure regulator 15 and the M meter 16 are supplied with gas. Becomes to flow, and it becomes possible to monitor the minute flow rate of gas flowing through the gas supply path 4b. At this time, if there is no gas consumption and no minute gas leakage occurs, neither the parent gas meter 7 nor the M meter 16 can detect the gas flow rate.

On the assumption that such a phenomenon occurs at least once during a relatively long predetermined period of 30 days, for example, if the parent gas meter 7 is operated during this predetermined period.
When the gas flow rate is not detected by both the M meter 16 and the M meter 16, it can be determined that a minute gas leak has occurred.

As described above, the bypass passage is provided in a part of the gas supply passage, and the regulators having different adjustment pressures allow the gas to flow into the bypass passage at a low flow rate, and the minute flow amount provided in the bypass passage can be detected. Since the flow rate is monitored by the meter to detect the minute gas leakage, it is possible to easily and surely detect the gas leakage of the gas supply pipe without stopping the gas supply.

When constructing the gas supply facility, L
Although it is necessary to stop the gas supply from the P gas container, gas supply facilities for multiple dwelling houses have many gas supply households. You have to make sure you are not using. This is because, if the gas supply is stopped without checking, the gas equipment that was in use will disappear, and when the gas supply is restarted after the construction is completed, raw gas will be ejected from the gas equipment that has disappeared, which is dangerous. Because there is. However, since it is practically difficult to check the presence or absence of gas usage in all households, it is possible to detect the presence or absence of gas usage by the presence or absence of the gas flow rate in the bypass channel of the gas leak detection device. There is.

[0009]

In the above-described conventional gas leakage detection device, the outlet pressure of the parent pressure regulator and the gas flow from the child pressure regulator whose set value is changed are monitored by a membrane gas meter, It was judged that there was leakage because it did not drop below 3 liters / hour even once a day. Therefore, if there is a slight pipe leakage of, for example, 3 liters / hour, the flow rate of at least one cycle of the membrane gas meter, for example, 0.7 liters / hour.
The time that the gas corresponding to the time flows, that is, 60 minutes ×
(0.7 liter / 3 liter) = Unable to measure within 14 minutes. In other words, there is a problem in that no leak can be detected unless the gas is stopped for a certain housing time, for example, 14 minutes or more within 30 days.

Further, when the presence / absence of gas is detected by the presence / absence of the gas flow rate in the bypass passage of the gas leakage detection device using the membrane gas meter, it is confirmed that all households are not using the gas. To be able to see,
Since the operating principle of the membrane gas meter is time-consuming, there is a problem that it takes time to check the unused gas before performing the work, such as when repairing the existing equipment, and it is difficult to complete the work.

Further, since a meter for measuring the flow rate is separately installed by a dedicated pipe only for detecting the leak,
In addition to the increase in size of the entire device, there is a problem in that the piping work for assembling this device becomes very complicated and troublesome, resulting in an increase in cost. In particular, when it is installed in the existing equipment, the compatibility with the existing equipment at the time of replacement is poor, and a long working time is required for the replacement, which causes a problem from the viewpoint of cost increase.

Therefore, in view of the above-mentioned conventional problems, the present invention can detect the absence of gas and the absence of gas by monitoring the gas flow rate for a shorter period of time and detecting the absence of gas flow rate for a shorter period of time. The main object is to provide a gas leakage detection device that has

Another object of the present invention is to provide a gas leakage detection device which is compact and simplifies piping work so that compatibility with existing devices can be improved and replacement work time can be shortened. It is an issue.

[0014]

In order to solve the above-mentioned problems, the invention according to claim 1 made in accordance with the present invention is, as shown in the basic configuration diagram of FIG. 1, a parent pressure provided in an LP gas supply pipe. Regulator 6, a child pressure regulator 15 having a higher regulating pressure than the parent pressure regulator provided in a bypass gas flow path bypassing the parent pressure regulator, and a flow rate for measuring the gas flow rate of the bypass gas flow channel It is detected that gas leakage has occurred on the downstream side of the parent pressure regulator due to the gas flow rate flowing through the bypass gas flow path measured by the measurement means 20 and the flow rate measurement means being maintained for a predetermined period, the gas leak detection system and a controller 22 for alarm display the該検out gas leak consists instantaneous flow meter the flow rate measuring means for measuring the instantaneous gas flow rate, said controller, said flow Also used as an operating power supply of the measuring means
Battery power supply 223, gas flow rate presence / absence detection means 221a-1 for detecting the presence / absence of the gas flow rate measured by the flow rate measurement means in response to the input of the request signal, and gas usage based on the result detected by the gas flow rate presence / absence detection means. Gas use presence / absence display means 222c for displaying presence / absence and input of the request signal
Start the time measurement according to the
Stop the operation of the detection means and the gas use presence / absence display means.
The gas leak detection device is characterized in that it has a clocking means (T) .

In the above structure, from the instantaneous flow meter provided in the bypass gas flow path that bypasses the parent pressure regulator 6 provided in the LP gas supply pipe together with the child pressure regulator 15 having a higher regulated pressure than the parent pressure regulator 6. By the flow rate measuring means 20 which measures the gas flow rate of the bypass gas flow path and the gas flow rate flowing through the bypass gas flow path continues for a predetermined period,
It is detected that gas leakage has occurred on the downstream side of the parent pressure regulator 6, and an alarm is displayed for the detected gas leakage. Moreover, the flow rate measuring means 2 is provided in response to the input of the request signal.
The presence / absence of the gas flow rate measured by 0 is detected by the gas flow presence / absence detecting means 221a-1, and the presence / absence of gas usage is displayed on the gas usage presence / absence displaying means 222c based on the detection result of the presence / absence of the gas flow quantity. Therefore, it is possible to monitor the gas flow rate for detecting the gas leakage and for determining the gas usage by constantly monitoring the instantaneous flow rate.

[0016]

Further, the controller operates by a battery power supply 223 is also used as an operating power supply of the flow rate measuring means with itself, but the gas flow rate detecting means counting means T is after a certain time to start counting by the input of the request signal Also, since the operation of the gas use presence / absence display means is stopped, the battery power is not wastefully consumed.

The invention described in claim 2 was made by the present invention, as shown in the basic diagram of Fig. 1, in a gas leak detection system according to claim 1 Symbol placement, the controller, the master pressure regulator , The child pressure regulator, the flow rate measuring means, and the bypass gas flow path are integrated into a gas leakage detection device.

In the above structure, since the controller 22 is integrated with the parent pressure regulator, the child pressure regulator, the flow rate measuring means and the bypass gas flow passage, it can be assembled without any piping.

[0020] The present invention invention according to claim 3 which is made by, as shown in the basic diagram of Fig. 1, claim 1 or 2
Further comprising the controller, the flow rate gas flow rate measured by the measuring means and the pressure in the gas leak detection system according, the pressure sensor 24 for detecting the gas pressure on the downstream side is provided on the downstream side of the flow rate measuring means Based on the pressure detected by the sensor, a pressure abnormality detection means 221a-2 for detecting an abnormality in the closing pressure and the supply pressure of the parent pressure regulator and the child pressure regulator, and an abnormality detection by the pressure abnormality detection means are warned. The gas leak detection apparatus further comprises an abnormal alarm display unit 222b for displaying.

In the above structure, the pressure sensor 24 measures the gas pressure on the downstream side of the flow rate measuring means, and the controller 2
2 based on the gas flow rate measured by the flow rate measuring means by the pressure abnormality detecting means 221a-2 and the pressure detected by the pressure sensor 24, the abnormality of the closing pressure and the supply pressure of the parent pressure regulator and the child pressure regulator is detected. Since the abnormality alarm display means 222b detects the abnormality by the pressure abnormality detection means 221a-2, it detects the gas leakage and the regulator closing pressure and the supply pressure abnormality, and gives an alarm by the display. be able to.

The invention according to claim 4 made according to the present invention is, as shown in the basic configuration diagram of FIG. 1, the gas leakage detection device according to any one of claims 1 to 3 , The gas inlet 6a of the parent pressure regulator and the gas inlet 15a of the child pressure regulator are formed in the respective structures to form a gas outlet 15b of the child pressure regulator and a gas inlet 20a of the flow rate measuring means. And the gas outlet 2 of the flow rate measuring means by the passages formed in both structures.
0b and the gas outlet 6b of the parent pressure regulator are communicated with each other through passages formed in both structures, respectively.

In the above structure, the parent pressure regulator 6, the child pressure regulator 15, and the flow rate measuring means 20 are communicated with each other through the passages formed in these structures, respectively.
The integration will be done organically.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment of a gas leakage detection device according to the present invention incorporated into a gas supply facility for supplying gas to a housing complex such as an apartment, and in FIG. 2, it is equivalent to the conventional part described above with reference to FIG. The same reference numerals are given to the parts, and detailed description thereof will be omitted.

In the present embodiment, one of the pair of inlets is switched to select one, and the LP on the downstream side of the primary regulator 5 that regulates the gas from the gas supply source connected to this inlet to a predetermined pressure. The gas supply pipe is provided with a parent pressure adjuster 6 for reducing the gas pressure to the supply pressure, and a bypass gas flow provided so as to connect the inlet side and the outlet side of the parent pressure adjuster 6 to bypass them. The passage is characterized in that a child pressure regulator 15 and a small instantaneous flowmeter 20 capable of measuring the instantaneous gas flow rate are sequentially provided from the inlet side. The instantaneous flowmeter 20 functions as a flow rate measuring means for measuring the gas flow rate of the bypass gas flow path, and is constituted by, for example, an IC flow sensor, and as shown in a partially enlarged view of FIG. It is placed and integrated with the container 15 and the controller 22. The parent pressure regulator 6 has a pressure sensor (not shown) built in on the outlet side thereof.

When the above-mentioned structure is schematically illustrated, as shown in FIG. 4, the slave pressure regulator 15 and the instantaneous flowmeter 20 are mounted on the master pressure regulator 6 provided on the downstream side of the primary regulator 5. Has been done. The gas inlet 6a of the parent pressure regulator 6 and the gas inlet 15a of the child pressure regulator 15 are formed by passages formed in both structures, and the gas outlet 15b of the child pressure regulator 15 is formed.
And the gas inlet 20a of the instantaneous flowmeter 20 are formed by the passages formed in both structures, and the gas outlet 20b of the instantaneous flowmeter 20 and the gas outlet 6b of the parent pressure regulator 6 are formed in both structures. The passages communicate with each other. The gas inlet 6a and the gas outlet 6b of the parent pressure regulator 6 are used as a set of connection ports that connect the gas leakage detection device to the LP gas supply pipe. Further, in the parent pressure regulator 6, a pressure sensor 24 that detects the pressure at the gas outlet 6b and outputs a pressure signal according to the magnitude of the pressure.
Is built in.

The parent pressure regulator 6 and the child pressure regulator 1
Basically, 5 operates according to the same principle to keep the gas pressure at the outlet within a predetermined range, and the following may be used, for example. That is, a diaphragm on which one surface exerts a predetermined urging force and the other surface acts on the gas pressure of the outlet, and an on-off valve which is opened and closed by a valve body interlocking with the diaphragm is provided between the gas inlet 6a and the gas outlet 6b. The opening / closing valve closes when the gas pressure at the outlet increases as the diaphragm is displaced against the urging force, and the opening / closing valve opens when the gas pressure at the outlet decreases as the diaphragm is displaced by the urging force. , The gas pressure at the outlet, that is, the gas supply pressure is maintained within a predetermined range. When it is confirmed that the gas flow rate measured by the instantaneous flow meter is 0 and the gas is no longer used on the downstream side, the on-off valve will close, but the gas pressure at the outlet at this time is the parent pressure adjustment. When the container and child pressure regulator are functioning normally, the closing pressure is maintained below a predetermined value.

The parent pressure regulator 6 is set so as to be closed by the outlet gas pressure slightly smaller than that of the child pressure regulator 15, so that the child pressure regulator 15 is closed even after the parent pressure regulator 6 is closed. Is continuously opened, the gas is supplied mainly through the child pressure regulator 15 when the gas consumption on the downstream side is small and the outlet gas pressure is relatively high.

As the instantaneous flowmeter 20, for example, Japanese Patent Publication No. 6
The flow sensor as shown in FIGS. 5 to 7 described in Japanese Patent Publication No. 43906 can be applied. That is, as shown in FIG. 5, a through hole 4 that connects the left and right openings 2 and 3 is formed by anisotropic etching in the center of the semiconductor substrate 1, and a semiconductor substrate is formed above the through hole 4. A bridge portion 5 is spatially separated from the base 1 in a bridge shape, and as a result, a bridge portion 5 that is thermally insulated from the semiconductor base 1 is formed. This bridge part 5
A thin-film heater element 7 and thin-film temperature measuring resistance elements 8 and 9 sandwiching the thin-film heater element 7 are arranged on the surface of the. Further, a thin film ambient temperature measuring resistance element 10 is formed at a corner of the semiconductor base 1. Incidentally, 6 is a protective film made of a material having a low thermal conductivity.

The operation will be described with reference to FIGS. 6 (a) and 6 (b) showing the cross section and its temperature distribution. The heater element 7 is heated to a certain temperature th5, th6 (for example, 63.degree. C.) higher than the ambient temperature. : When the temperature is controlled based on the ambient temperature, the temperatures t6 and t7 of the temperature measuring resistance elements 8 and 9 (for example, 35 °).
C: ambient temperature reference), as shown in FIG. 6B showing the temperature distribution of each element, the temperature of the heater element 7 is th5,
It is substantially symmetrical about th6. At this time, when the gas moves from the direction of arrow 11 in FIG. 5, the temperature measuring resistance element 8 on the upstream side is cooled and the temperature is lowered by ΔT6. On the other hand, in the temperature measuring resistance element 9 on the downstream side, heat conduction from the heater element 7 is promoted by using the gas flow as a medium, and the temperature is Δ
A temperature difference occurs because the temperature is raised by T7. Therefore, by incorporating the heater elements 8 and 9 in the Wheatstone bridge circuit, the temperature difference can be converted into a voltage, a voltage output according to the flow velocity can be obtained, and the flow velocity of gas can be detected as shown in FIG. . If the flow velocity is known, the flow rate can be known by taking the product of the flow passage cross-sectional area.

Although not shown in the schematic diagram of FIG. 4, the controller 22 mounted on the master pressure regulator 6 together with the slave pressure regulator 15 and the instantaneous flow meter 20 is as shown in FIG. , A microcomputer (μCOM) 221 that operates according to a predetermined program, a display unit 222 that performs various displays such as a warning display, and a battery power supply 223 that does not require wiring work for a commercial power supply
And a switch 22 as a request signal generating means including a reed switch that is turned on when an operation tool with a built-in magnet is brought close to the outside of the case of the controller 22, for example
4 and.

The μCOM 221 is a central processing unit (CPU) 221a for performing arithmetic processing and control processing according to a predetermined program, and a read-only memory (ROM for storing programs used for processing in the CPU 221a and various fixed data). ) 221b and CPU
A readable / writable memory (RAM) 22 having various areas used by the processing 221a.
1c and.

The display unit 222 is provided with an indicator 222a as a leak warning display means, an indicator 222b as an abnormality warning display means, and an indicator 222c as a gas use presence / absence display means. The indicator 222c is a two-color indicator and is always in a non-lighting state, but is lit in one color depending on whether gas is used or not during the gas use presence / absence display period.

The controller 22 is connected to the pressure sensor 24 and the instantaneous flowmeter 20 described above, and the controller 22
Through the internal CPU 221a, a pressure signal having a magnitude corresponding to the outlet gas pressure of the parent pressure regulator 6 detected by the pressure sensor 24 and outputted, and a child pressure regulator 15 detected by the instantaneous flow meter 20 and outputted. A flow rate signal corresponding to the flow rate of the gas flowing through the bypass gas flow path 14 and a request signal generated when the switch 224 is turned on are input.

In the configuration described above, when the gas consumption at night or at midnight is almost eliminated, the pressure at the gas supply pipe 4 and the outlet 6b of the parent pressure regulator 6 becomes high, and the parent pressure regulator 6 is closed to make the child pressure. The gas is allowed to flow only to the regulator 15 and the instantaneous flow meter 20, and the minute gas flow rate flowing through the gas supply path 4 on the downstream side of the parent pressure regulator 6 can be monitored. At this time, if there is no gas consumption and no minute gas leakage occurs, neither the parent gas meter 7 nor the instantaneous flow meter 20 can detect the gas flow rate.

On the premise that such a phenomenon occurs at least once during a relatively long predetermined period of 15 days, for example, the instantaneous flow meter 20 is provided during this predetermined period.
When the gas flow rate cannot be detected without fail, it can be determined that a minute gas leak has occurred.

As described above, the bypass flow passage is provided in a part of the gas supply passage, and the regulators with different adjustment pressures allow the gas to flow into the bypass flow passage at a low flow rate, and the minute flow amount provided in the bypass flow passage can be detected. Since the flow rate is monitored by the flow meter 20 to detect the minute gas leak, the gas leak detection of the gas supply pipe can be performed without stopping the gas supply.
It can be done easily and reliably.

In the above-described gas leakage detection device, the outlet pressure of the parent pressure regulator and the flow of gas from the child pressure regulator whose set value is changed are monitored by the instantaneous flow meter 20, and for example, a predetermined leakage judgment on the 15th is performed. It can be judged that there is a gas leak because the period does not reach 0 liter / hour even once, and when there is a slight pipe leak of, for example, 3 liters / hour, that can be confirmed by the instantaneous flow meter 20 every few seconds. Since it can be confirmed by the flow rate signal, it is possible to detect the absence of leakage even if the gas stops in a housing complex in a certain leakage determination period even for a short time.

Further, since it is not necessary to separately install something for detecting leakage, and it is not necessary to install a dedicated pipe for this purpose, there is no need to increase the size of the entire apparatus and this apparatus is assembled. There is no need for new piping work for this purpose, and especially when it is installed in existing equipment, compatibility is good when exchanging with existing equipment, and a long working time is not required for replacement, so there is no increase in costs.

By using the instantaneous flow meter 20 as described above, the slave pressure regulator 1 is operated at a predetermined cycle of, for example, several seconds.
The flow rate from 5 is measured, and the flow rate is zero for a certain period of time.
If not, it is determined that there is a leak. Since the flow rate measurement for determining that the gas flow rate is 0 can be performed in a unit of several seconds, it is possible to perform the leak determination as compared with the case where it takes a long time to determine that the gas flow rate is 0. The required determination period can be shortened.

Further, when an operation tool with a built-in magnet (not shown) is brought close to the outside of the case of the controller 22 to turn on the switch 224 consisting of a reed switch, the input of the CPU 221a changes accordingly, and this change is input as a request signal. Then, the operation of checking whether the gas is being used is started. In this operation, the instantaneous flow meter 20
It is judged whether the gas flow rate calculated by reading the signal according to the flow velocity generated by
When the gas flow rate is not 0, it indicates that the gas is being used, for example, by lighting the indicator 222c in red, and when the gas flow rate is 0, it indicates that the gas is not in use, for example, by lighting the indicator 222c in green.

Moreover, the CPU 221a uses the switch 224.
When a request signal generated by turning on is input, for example, the clocking of a predetermined time of several minutes is started, and when the clocking of the fixed time is finished, the operation of checking whether the gas is in use and the result is lit. The indicator 222c is turned off. Therefore, when the gas supply is stopped during the gas piping work, the check operation and the display of the check result will be performed only for a predetermined period to obtain the necessary information to confirm whether the gas is being used. Power consumption can be minimized.

Further, since the pressure signal from the pressure sensor 24 built in the outlet of the parent pressure regulator 6 is input to the controller 22, the supply pressure and the closing pressure can be constantly monitored, and when abnormal, it serves as a display means. The display unit 222 can display the abnormality of the regulator as well as the leakage abnormality.

Further, the RAM 22 in the controller 22
In 1c, the gas flow rate measured by the instantaneous flow meter 20 and the gas pressure measured by the pressure sensor 24 are appropriately stored and recorded. And these stored contents are
A memory card which is read by the CPU 221a in response to the input of a request signal from a recording device (not shown) connected to the controller 22 in a detachable manner, is sent to the recording device, and is detachably attached to the recording device. It can be re-recorded on the recording medium. In this case, C
The PU 221a can also function to read out and send out at least one of the recorded contents in response to a request from the outside.

Hereinafter, μ which constitutes the controller 22
The details of the operation will be described with reference to the flowcharts of FIGS. 9 and 10 showing the processing performed by the CPU 221a in the COM. In the figure, the CPU 221a starts its operation when the power is turned on, and in the first step S1, initialization such as storing various predetermined constants in a predetermined area of the RAM is performed, and then the process proceeds to step S2 to make a request. It is determined whether or not the switch 224 as the signal generating means is turned on. When the determination in step S2 is YES, the process proceeds to step S3 and it is determined whether or not the switch flag SF is turned on. When the determination in step S3 is NO, the process proceeds to step S4, the SF is turned on, and then the process proceeds to step S5 to start the timer T which is a time-out in a few minutes, and then proceeds to step S6.

This timer T is formed in a predetermined area in the RAM 221c, and when the content of this area, which is incremented every unit time, reaches a predetermined value, the time is over.
When the determination in step S2 is NO, step S2
If the determination in step S3 is YES, steps S4 and S5 are skipped and the process proceeds to step S6.

In step S6, the pressure sensor 24
The pressure signal having a magnitude corresponding to the outlet gas pressure of the parent pressure regulator 6 detected and output by the A / D converter is read, and the outlet gas pressure P is measured based on the read pressure signal. Is stored in a predetermined area of the RAM 221c and then the process proceeds to step S7 to determine the presence / absence of gas flow. This determination is based on a gas flow rate Q measured in a flow rate measurement that is periodically executed by a timer interrupt, which will be described later, and is counted up when a gas flow is present and reset when the gas flow is zero. It is performed depending on whether the count value is 0 or not.

As a result of the determination in step S7, when the gas flow is present, the process proceeds to step S8 and it is determined whether the SF is on. The determination in step S8 is YES
If so, proceed to step S9 and display the indicator 222c.
Outputs a signal that lights up red. When the determination in step S8 is NO, the process proceeds to step S10, in which it is determined whether the gas flow continues for a predetermined period. The determination in step S10 is up-counted when there is a gas flow and reset when the gas flow is 0, based on the gas flow rate Q measured in the flow rate measurement that is periodically executed by a timer interrupt described later. Depending on whether or not the count value of the counter is greater than or equal to the value corresponding to the predetermined period.

When the determination in step S10 is NO,
That is, when the gas flow has not continued for the predetermined period, the process proceeds to step S11. As the predetermined period, for example, an arbitrary number of days of 15 days or less is set in advance. Step S1
In No. 1, it is determined whether or not the gas flow rate Q measured by the timer interrupt is less than a predetermined flow rate value Q1, and when this determination is NO, the process proceeds to step S12 and the timer interrupt is performed. It is determined whether the gas flow rate Q is greater than or equal to a predetermined flow rate value Q2. The flow rate value Q1 is set to the value of the gas flow rate through which the gas flows only through the child pressure regulator 15, and the flow rate value Q2 is set to the value of the flow rate through which the gas also flows to the parent pressure regulator 6.

When the measured flow rate Q is greater than or equal to Q1 and less than Q2, the determination in step S12 is NO and the process proceeds to step S13, in which it is determined whether the timer T has timed out. If the determination in step S13 is NO, immediately, and if YES in step S14, the SF is turned off in step S14, and then the process returns to step S2 to repeat the above process.

As a result of the determination in step S7, if there is no gas flow, the process proceeds to step S15, where it is determined whether SF is on. When the determination in step S15 is YES, the process proceeds to step S16, and a signal for lighting the indicator 222c in green is output. When the determination in step S15 is NO, the process proceeds to step S17, and it is determined whether or not the pressure P measured in step S6 is equal to or lower than a predetermined pressure value P5. Pressure value P5
For example, 350 mmH ₂ O is set. When the determination in step S17 is YES, that is, when the measured pressure P is less than or equal to the pressure value P5, it is determined that there is no abnormality in the closing pressures of both the parent pressure regulator 6 and the child pressure regulator 15, and the above step S13 or S14 is performed. It returns to the above step S2 via. On the other hand, when the determination in step S17 is NO, that is, when the measured pressure P exceeds the pressure value P5, the process proceeds to step S18, and the closing pressure of the parent pressure regulator 6 and / or the child pressure regulator 15 is abnormal. If there is,
After the blocking pressure abnormality flag of the predetermined area of the RAM 221c is set, the process returns to the step S2 via the step S13 or S14.

When the determination in step S10 is YES, that is, when the gas flow continues for a predetermined period, the process proceeds to step S19, where it is determined that the gas flow is generated on the downstream side, the leak is detected, and the RAM 221c is stored. After the leakage abnormality flag of the predetermined area is set, the process returns to step S2 via step S13 or S14.

When the determination in step S11 is YES, that is, when the measured gas flow rate Q is less than the predetermined flow rate value Q1, the process proceeds to step S20, where the pressure P measured in step S6 is predetermined. It is determined whether or not the pressure value is within the range of P3 to P4. The pressure values P3 and P4 are, for example, 310 mmH ₂ O, 330
mmH ₂ O is set respectively. When the determination in step S20 is YES, that is, the measured pressure P is the pressure value P.
When it is within the range of 3 to P4, it is determined that there is no abnormality in the supply pressure of the child pressure regulator 15, and the process returns to the above step S2 via the above step S13 or S14. On the other hand, when the determination in step S20 is NO, that is, the measured pressure P
Is not within the range of pressure values P3 to P4, step S
21, the child pressure regulator 15 in the predetermined area of the RAM 221c is determined to be abnormal in the supply pressure of the child pressure regulator 15.
After setting the abnormality flag indicating that the supply pressure is abnormal, the process returns to step S2 via step S13 or S14.

When the determination in step S12 is YES, that is, when the measured gas flow rate Q is equal to or greater than the predetermined flow rate value Q2, the process proceeds to step S22, where the pressure P measured in step S6 is predetermined. It is determined whether or not the pressure values are within the range of P1 and P2. The pressure values P1 and P2 are, for example, 225 mmH ₂ O, 305
mmH ₂ O is set respectively. When the determination in step S22 is YES, that is, the measured pressure P is the pressure value P.
When it is within the range of 1 to P2, it is determined that there is no abnormality in the supply pressure of the parent pressure regulator 6, and the above step S13 or S
The procedure returns to step S2 via 14. On the other hand, when the determination in step S22 is NO, that is, when the measured pressure P is not within the range of pressure values P1 and P2, step S2
3, the supply pressure of the master pressure regulator 6 is determined to be abnormal, and an abnormality flag indicating that the supply pressure of the master pressure regulator 6 in the predetermined area of the RAM 221c is abnormal is set, and then the above step S13 or S14 is performed. And returns to step S2.

In the process of executing the steps S1 to S23, the timer interrupt shown in FIG. 10 is executed at a cycle of, for example, about 5 to 7 seconds, and in the first step S31, the child pressure detected and output by the instantaneous flow meter 20. A flow rate signal corresponding to the flow rate of the gas flowing through the bypass gas flow path 14 is read through the adjuster 15, the gas flow rate Q is measured based on the read flow rate signal, and the measurement result is stored in a predetermined area of the RAM 221c before the step. Go to S32 and gas flow rate is 0
Or not. If the determination in step S32 is no, the process proceeds to step S33 and the RAM 221c
After counting up the counter formed in the predetermined area by +1, the process returns to the flowchart of FIG. On the other hand, when the determination in step S32 is YES, that is, when the gas flow rate Q is 0, the process proceeds to step S34 to reset the counter and then returns to the flowchart of FIG.

Therefore, it is possible to judge that the gas flow rate Q has become 0, that is, there is no gas flow because the count value of the counter is 0, and the count value of the counter has a timer interrupt period T. By multiplying by, we can see that the gas flow continues for that amount of time without interruption.

As is clear from the above description with reference to the flow chart, the CPU 221a serves as gas flow rate presence / absence detection means 221a-1 for detecting the presence / absence of the gas flow rate measured by the instantaneous flow meter 20 in response to the input of the request signal. Besides, based on the gas flow rate measured by the instantaneous flow meter 20 and the pressure measured by the pressure sensor 24, the closing pressure and supply pressure of the parent pressure regulator 6 and the child pressure regulator 15 are diagnosed to detect an abnormality. The pressure abnormality detection means 221a-2 respectively function.

According to the embodiment described above with reference to the drawings, the gas inlet 6a of the parent pressure regulator 6 and the gas inlet 15a of the child pressure regulator 15 are respectively formed in the two structures by the passages. The gas outlet 15b of the pressure regulator 15 and the gas inlet 20a of the instantaneous flowmeter 20 are formed by passages formed in both structures, and the gas outlet 20b of the instantaneous flowmeter 20 and the gas outlet 6b of the parent pressure regulator 6 are connected. Are integrated by being configured so as to communicate with each other through the passages formed in both structures, respectively. However, in the leakage detection (membrane type microcomputer) M meter 16 of the conventional device shown in FIG. Instead of the M meter, a sensor box accommodating an instantaneous flow meter, a pressure sensor, etc. may be attached.

However, by constructing like the illustrated embodiment, the independently assembled parent pressure regulator 6, child pressure regulator 15, and instantaneous flowmeter 20 can be integrated so as to be separable from each other. It is convenient for maintenance because it can be easily replaced when any failure occurs. However, without being limited to this embodiment, the parent pressure regulator 6, the child pressure regulator 15, and the instantaneous flow meter 20 are incorporated in a single structure, and a passage for communicating these is also formed together. Alternatively, the structures may be integrated by connecting the structures with each other through a short conduit.

Further, according to the illustrated embodiment, one set of connection ports for connecting to the LP gas supply pipe includes the gas inlet 6a and the gas outlet 6b of the parent pressure regulator 6, but The gas inlet of the pressure regulator 15 and the gas outlet of the instantaneous flowmeter 20 are connected to the LP gas supply pipe, and the parent pressure regulator 6 is connected.
May be attached to the LP gas supply pipe via these. However, by configuring as in the illustrated embodiment, that is, the parent pressure regulator 6 having a relatively larger shape than the child pressure regulator 15 and the instantaneous flowmeter 20.
The gas inlet 6a and the gas outlet 6b are connected to the LP gas supply pipe, and the child pressure regulator 15, the instantaneous flowmeter 20 and the controller 22 are mounted on the parent pressure regulator 6, Is stable and preferable.

Furthermore, since the gas flow rate of the bypass gas flow path can be measured as an instantaneous flow rate, a flow rate of 0 for detecting gas leakage and gas use can be detected even if the gas is not used for a short time. It becomes possible to shorten the monitoring period for leak judgment and gas unused detection.

Further, in the flow chart of FIG. 10, the count value of the counter is reset by one flow rate 0. However, if a backflow of gas may occur due to gas pressure fluctuation, the flow rate 0 may be set by the instantaneous flow rate. If it is detected, the gas flow rate of 0 may be erroneously detected.
It may be better to reset the count value when the flow rate becomes 0 several times in succession. Even in this case, the leak determination period can be shortened by using the instantaneous flow meter.

In the above-described embodiment, whether or not gas is used is displayed by the lighting color of a single indicator, but it is displayed by lighting or not lighting the indicator, or by using a dot display or the like. It may be performed by displaying the characters "No", but it is preferable to positively display that gas is not used in order to judge that gas is not used by the display.

Although the gas flow rate and the gas pressure are recorded in a predetermined area of the RAM in the above-mentioned embodiment, the record can be held without a backup power source by incorporating a non-volatile memory. You may do it. Also,
For example, the latest 1
Use a capacity that allows you to record for about a month,
Instead of the old record, the latest record of gas flow rate and gas pressure may be retained. Even in this case, it is sufficient as a record for confirming the history of the gas flow rate and the gas pressure by, for example, an alarm display.

Although the parent pressure regulator, the child pressure regulator, the instantaneous flow meter, the pressure sensor and the controller are integrally installed in the above-mentioned embodiment, the installation form is not limited to this. However, instead of the M meter 16 for leak detection (membrane type microcomputer) of the conventional apparatus shown in FIG. 11, a sensor box accommodating an instantaneous flow meter, a pressure sensor, etc. is attached. May be. In this case, the gas flow rate for gas leak detection can be monitored by constantly monitoring the instantaneous flow rate. It is possible to easily change to a device that can detect gas leakage early by shortening the time required for both.

[0066]

As described above, according to the present invention as set forth in claim 1, the bypass gas passage bypassing the parent pressure regulator provided in the LP gas supply pipe has a higher regulated pressure than the parent pressure regulator. Since the gas flow rate in the bypass gas flow path measured by the instantaneous flowmeter installed with the slave pressure regulator continues for a specified period of time, a gas leak is detected and an alarm is displayed. The gas leakage in the LP gas supply pipe that supplies a large amount of gas can be detected by monitoring the gas flow rate for a short time by the flow rate measuring means having a small capacity, and the flow rate monitoring interval for leak detection and the period required for the leak determination can be Both can be shortened, and gas leaks can be detected earlier. Moreover, since the presence or absence of the gas flow rate measured by the instantaneous flow meter is detected according to the input of the request signal and the presence or absence of the gas is displayed based on the detection result of the presence or absence of the gas flow rate, it is necessary to judge the gas use. The gas flow rate can be detected by constantly monitoring the instantaneous flow rate, and the absence of gas can be detected by monitoring the gas flow rate for a shorter period of time. .

[0067] Even using a battery power supply as an operating power supply to unnecessary commercial power construction, after a certain from the input of the request signal time since stopping the operation of the gas flow rate detecting means and the gas used whether display means, It is possible to prevent wasteful consumption of the battery power without troublesome operation, and to use the battery for a long time without replacing the battery, thereby reducing the maintenance cost.

[0068] According to the present invention of claim 2 Symbol mounting, the controller is master pressure regulator, child pressure regulator is integrated with the flow rate measuring means and the bypass gas flow passage, be assembled without requiring any plumbing By reducing the size and simplifying the piping work, compatibility with existing equipment can be improved, replacement work time can be shortened, and cost can be reduced. .

[0069] claimed according to claim 3 Symbol mounting of the present invention, is as spread of devices that can be alarm by abnormalities detected and displayed occlusion pressure and supply pressure of the regulator in addition to the gas leakage can be achieved Accidents due to leakage and abnormal pressure can be prevented.

[0070] According to the present invention of claim 4 Symbol mounting, parent pressure regulator, child pressure regulator, since the organically integrated in communication with each other by passages formed respectively in the structure of the instantaneous flow meter, A smaller device is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a gas leakage detection device according to the present invention.

FIG. 2 is a diagram showing an embodiment of a gas leakage detection device according to the present invention incorporated into a gas supply facility.

FIG. 3 is a partially enlarged view of FIG.

FIG. 4 is a diagram schematically showing the configuration of a gas leakage detection device according to the present invention.

5 is a perspective view showing an example of a flow sensor as an instantaneous flow meter in FIG.

6 is a diagram showing a cross section and a temperature distribution of the flow sensor of FIG.

FIG. 7 is a graph showing a flow velocity-output characteristic of the flow sensor of FIG.

FIG. 8 is a block diagram showing a configuration of the gas leakage detection device in FIG.

9 is a flowchart showing a main process performed by a CPU in FIG.

10 is a flowchart showing a timer interrupt process performed by the CPU in FIG.

FIG. 11 is a diagram showing an example of a conventional gas leakage detection device incorporated in a gas supply facility.

[Explanation of symbols]

6 Parent pressure regulator 6a Gas inlet 6b Gas outlet 15 Child pressure regulator 15a Gas inlet 15b Gas outlet 20 Flow rate measuring means (instantaneous flow meter) 20a Gas inlet 20b Gas outlet 22 Controller 221a-1 Gas flow rate presence / absence detecting means (CPU) 221a-2 Pressure abnormality detection means (CPU) 222b Abnormality alarm display means (indicator) 222c Gas use presence / absence display means (indicator) 223 Battery power supply 24 Pressure sensor T Timing means

Continuation of the front page (56) Reference JP-A-3-41300 (JP, A) JP-A-6-307971 (JP, A) JP-A-8-43246 (JP, A) JP-A-9-145526 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01M 3/00 F17D 5/02 G01F 1/00

Claims (4)

(57) [Claims] 1. A parent pressure regulator provided in an LP gas supply pipe, and a child pressure regulator having a higher regulated pressure than the parent pressure regulator provided in a bypass gas flow path bypassing the parent pressure regulator, Flow rate measuring means for measuring the gas flow rate of the bypass gas flow path, and the gas flow rate flowing through the bypass gas flow path measured by the flow rate measuring means is maintained for a predetermined period, so that it is located on the downstream side of the parent pressure regulator. In a gas leakage detection device including a controller that detects that a gas leakage has occurred and displays an alarm for the detected gas leakage, the flow rate measuring means is an instantaneous flow meter that measures an instantaneous gas flow rate, and the controller is , As the operating power source of the flow rate measuring means
Even the battery power source used , gas flow rate presence / absence detecting means for detecting the presence or absence of the gas flow rate measured by the flow rate measuring means in response to the input of the request signal, and the gas usage depending on the result detected by the gas flow rate presence / absence detecting means. Gas use presence / absence display means for displaying the presence / absence of the gas , and timing according to the input of the request signal
Start and after a certain time, the gas flow rate presence / absence detection means and the front
A gas leakage detection device, comprising: a time measuring means for stopping the operation of the gas use presence / absence displaying means . 2. The controller for adjusting the parent pressure
Device, the child pressure regulator, the flow rate measuring means, and the bypass
The gas leakage detection device according to claim 1, wherein the gas leakage detection device is integrated with the pass gas flow path . 3. A device provided downstream of the flow rate measuring means.
A pressure sensor for detecting the gas pressure on the flow side is further provided, and the controller measures by the flow rate measuring means.
Based on the gas flow rate and the pressure detected by the pressure sensor
The closing pressure of the parent pressure regulator and the child pressure regulator.
And a pressure abnormality detecting means for detecting an abnormality in the supply pressure,
Abnormality alarm that displays anomaly detection by force abnormality detection means
The gas leakage detection device according to claim 1 , further comprising a display unit . 4. The gas inlet of the parent pressure regulator and the child pressure
Form the gas inlet of the force regulator and the structure of both
The gas passage of the child pressure regulator and the flow rate
Form the gas inlet of the measuring means in both structures
Through the flow passage , and the gas outlet and front of the flow rate measuring means.
The gas outlet of the master pressure regulator and the structure of both
The gas leakage detection device according to claim 1, wherein the gas leakage detection device communicates with each other through the formed passage .