JPH0678961B2 - Gas leak inspection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention inspects a minute gas leak that occurs in a gas pipe from a shutoff valve that shuts off a gas flow path to a gas device, and reports the inspection result to the center. Gas leak inspection system.

[Conventional technology]

Conventionally, as the above-mentioned gas leakage inspection system, for example, a system in which a center and a terminal are respectively installed at an LPG seller and an LPG consumer is considered.

FIG. 7 is a block diagram showing a general configuration of this type of gas leakage inspection system. In FIG. 7, 11 is a center, 12 is a center network control unit (C-NCU), and 13 and 14 are subscriber lines. An exchange, 15 is a network control unit (NCU) 15a and control unit
Terminal control device having 15b, 16 and 17 are gas cylinders 18
To a gas device 19 to a gas pipe 20 and a shutoff valve, 21 is a telephone connected to the NCU 15a, the terminal control device 15, the gas meter 16 and shutoff valve 17 constitute a terminal, C- A communication line L connects the NCU 12 and the subscriber line exchange 13, the subscriber line exchanges 13 and 14, and the subscriber line exchange 14 and the terminal controller 15.

In the system having the illustrated configuration, the control unit of the terminal controller 15
15b has a built-in switch for manually opening and closing the shutoff valve 17, and the shutoff valve 17 has a built-in pressure sensor for detecting the gas pressure of the gas pipe 20 buried in the ground on the downstream side when the valve is closed.

In the above structure, the control unit 15b of the terminal control device 15 performs the work shown in the flowchart of FIG. 8 according to a predetermined program. The flow chart shown starts in response to the operation of the shutoff valve closing switch of the control unit 15b,
In the first step S1, a shutoff signal is output to the shutoff valve 17. After that, the process proceeds to step S2, in which the state of the pressure switch in the shutoff valve 17 is monitored to determine whether or not the pressure in the gas pipe 20 has dropped. There is a drop in pressure Step S2
If the determination is YES, the process proceeds to step S3, where it is determined that there is a minute gas leak, and in step S4 that follows, the center 11 is notified of that fact and the execution of the flowchart ends.

If the determination in step S2 is NO and there is no pressure drop, the process proceeds to step S5, in which it is determined whether 15 minutes have elapsed since the shutoff valve 17 was shut off, and the above step S2 is performed until the determination becomes YES. And the determination of step S5 is repeatedly executed. If the determination in step S5 is YES, that is, if the pressure does not decrease even after 15 minutes have passed, the process proceeds to step S6, where it is determined that there is no minute gas leakage, and the control unit 15 in the subsequent step S7.
A signal for opening the shutoff valve 17 is output in response to the operation of the shutoff valve closing switch of b, the shutoff valve is restored, and the execution of the flowchart ends.

Upon receiving the above-mentioned notification, the center 11 notifies the gas user of the terminal by telephone and has the shut-off valve 17 or the built-in shut-off valve of the gas meter 16 shut off, or the gas distributor goes to the terminal from the center. , Cut off by themselves.

[Problems to be Solved by the Invention]

In the above-mentioned conventional system, each terminal is inspected for a minute gas leak, and only when there is an abnormality, the center 11 can be notified of that fact.

However, recently, gas leaks from the buried part of the gas pipe are increasing, and it is becoming obligatory for gas sellers to keep a record of whether or not a minute gas leaks at regular intervals. ing. However, in the system described above, in order to record that there is no abnormality, a person of the gas distributor must go to each gas user's house and operate the shutoff valve closing switch of the control unit 15b of the terminal control device 15. There was a problem in that it was not possible to inspect for minute gas leaks in the gas pipe, and the burden on the contractor was extremely heavy.

Therefore, an object of the present invention is to provide a gas leakage inspection system capable of performing a gas leakage inspection of a gas pipe without the need for a company to go to a gas user's house.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the gas leakage inspection system according to the present invention connects a center 11 and a large number of terminals with a communication line L as shown in the basic configuration diagram of FIG.
Shut off the shut-off valve 17 provided on the 20 so that the gas equipment 19
In the gas leakage inspection system that inspects the minute gas leaks that occur in the gas pipe 20 up to and reports the inspection result to the center, a disconnection request signal that shuts off the shutoff valve for each terminal is provided in the communication line. Shutdown request signal sending means 11a for sending out via a communication line, the shutoff request signal from the previous term shutoff request signal sending means is input through the communication line, and the shutoff valve is actuated based on the input shutoff request signal. A shut-off valve shut-off means 32a ₁ for shutting off and a micro-gas leak inspection means provided at each terminal for inspecting a micro-gas leak by monitoring the pressure drop in the gas pipe from the shut-off valve to the gas equipment when shutting off the shut-off valve. and 32a _2, provided in each terminal, a storage unit 32b for storing the test results of small gas leakage due to the small gas leak test means, provided in each terminal, the small gas leak inspection means Leakage Problem means 32a for reporting to the center through the communication line test results of small gas leaks
₃ and a return request signal sending means 11b which is provided in the center and sends a return request signal for returning the shut-off valve to the open state to the terminal that has not been informed of the minute gas leakage through the communication line. And a shutoff valve restoring means 32a ₄ which is provided in each terminal and which inputs a restoration request signal from the restoration request signal sending means through a communication line and restores the shutoff valve to an open state based on the inputted restoration request signal. A safety check is performed by monitoring the pressure drop in the gas pipe from the shut-off valve provided in each terminal and opened by the shut-off valve resetting means to the gas equipment. the return safety confirmation means 32a ₅ for blocking, provided in the center, the result request signal sent through the communication line result request signal requesting a check result of a predetermined number of times stored in said storage means Output means 11c and each terminal, the result request signal from the result request signal sending means is input through a communication line, and based on the input result request signal, a predetermined number of times stored in the storage means. It is characterized by including a result notifying means 32a ₆ for reading out the inspection result and notifying the center of the read out inspection result.

[Action]

In the above configuration, in the terminal to which the shutoff request signal sent from the shutoff request signal sending means 11a of the center 11 is input through the communication circuit L, the shutoff valve shutoff means 32a ₁ shuts off the shutoff valve 17 and the shutoff valve shuts off. During the operation, the minute gas leakage inspection means 32a ₂ is connected to the gas equipment 20 from the shutoff valve to the gas equipment 19.
Inspect the micro gas leakage in the, the leak report means 32a ₃ reports the test result to the center 11 via the communication circuit, the storage means 32 provided in each terminal the test result.
b remembers. Therefore, the center 11 can inspect gas leakage at each terminal at any time, and the inspection result is left at each terminal.

The return request signal sending means 11b of the center 11 sends a return request signal for returning the shutoff valve to the open state to the terminal via the communication line when the inspected test result indicates that there is no slight gas leakage. In the terminal that receives this return request signal, the shutoff valve restoring means 32a ₄ restores the shutoff valve to the open state. Then, the return safety confirmation means 32a ₅ monitors the pressure drop in the gas pipe from the shutoff valve that has been opened to the gas equipment to perform safety confirmation, and when the safety cannot be confirmed, the shutoff valve is shut off again. After the gas leak inspection is completed, the gas can be used only when safety is confirmed.

Further, in the terminal to which the result request signal transmitted from the result request signal transmitting means 11c of the center 11 through the communication circuit L is input, the result notifying means 32a ₆ is stored in the storage means 32b for the predetermined number of past inspection results. Is read out and reported to the center, so that the center can know the past inspection result of each terminal when necessary.

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

FIG. 2 is a block diagram showing an embodiment of the gas leakage inspection system according to the present invention, in which the same parts as those of the conventional system described above with reference to FIG. 7 are designated by the same reference numerals. In FIG. 2, reference numeral 30 designates a subscriber line exchange.
Is a no ringing trunk (NRT) attached to the terminal, 31 is a terminal network controller (ANR-NCU), and 32 is a terminal controller to which the ANR-NCU 31 is put out.

The center 11 is, for example, a terminal installed in an appropriate place of an LPG dealer and installed in each of a large number of gas consumers (only one is shown in the figure, but a large number of terminals actually exist). ), It is possible to output a shutoff request signal for shutting off the shutoff valve at any time. The C-NCU 12 is connected to the center 11 through n signal lines and is attached to the center 11. The C-NCU 12 controls the communication between the center 11 and a large number of terminals on the side of the center 11. Do it in the ring.

The subscriber line exchanges 13 and 14 are installed in the central telephone station near the center 11 and the terminals, and perform telephone exchange operations based on the telephone numbers issued when calling from one to the other between the center 11 and the terminals. In particular, since the terminal side also uses the communication line L for the subscriber's telephone, the NRT 30 is connected to the subscriber's line exchange 14 so that the call can be received from the center 11 without ringing the telephone bell. Has been done. Since the center 11 side does not use the communication line L with the telephone,
NRT is not connected to the subscriber line exchange 13.

The ANR-NCU 31 is for connecting the terminal and the communication line L when there is an incoming call based on an outgoing call from the center 11 and when there is an outgoing call from the terminal. It is installed in the user's house.

As shown in FIG. 3, the terminal control device 32 includes a control unit 32a configured by a CPU that operates according to a predetermined program, and memory devices connected to the control unit 32a.
32b, indicator 32c, and shutoff valve opening / closing switch 32d.

The inspection operation of the minute gas leakage performed by the control unit 32a in the above configuration will be described with reference to the flowchart of FIG. The work of the flowchart is started by turning on the power to the control unit 32a, and its first step S11
At, it is determined whether a cutoff request signal is input from the center 11 through the NRT 30. At this time, the operator of the center 11 shuts off the shut-off valve 17 to the gas user's house of each terminal, and thus makes advance notification in advance that gas cannot be used temporarily.

When the determination in step S11 is NO and the shutoff request signal is not input, the process proceeds to step S12, where it is determined whether or not the shutoff valve 17 is closed by operating the shutoff valve opening / closing switch 32d. When the determination in step S12 is NO and the shutoff valve closing operation is not performed, the process returns to step S11.
If it is determined in step S11 that the shutoff request signal is input or that the shutoff valve closing operation is being performed in step S12, the process proceeds to the gas leakage inspection operation from step S13. Note that the step S12 is to perform the gas leakage inspection even when the gas user is a tenant or the like and manually operates the shut-off valve at the time of closing to return home.

In step S13, a shutoff signal is output to the shutoff valve 17 in response to the shutoff request signal or shutoff valve closing operation to shut off the shutoff valve 17. This cuts off the gas supply to the gas appliance 19 through the gas pipe A20.

Next, in step S14, the display 32c is turned on to notify the gas user that the inspection is being performed. After that, the process proceeds to step S15, where the output of the pressure sensor built in the shutoff valve 17 is monitored, and the shutoff valve is based on the output of the pressure sensor.
It is determined whether the pressure in the gas pipe 20 from 17 to the gas device 19 has dropped. If the determination in step S15 is YES and the pressure has dropped, the process proceeds to step S16, where it is determined that a slight gas leak has occurred. Next, in step S17, the result of the determination in step S16 and the data relating to the time at that time are stored in the memory device 32b. After that, the process proceeds to step S18, where the minute gas leak information is notified to the center 11 through the ANR-NCU31C-NCU12, and the display of the display 32c is turned off in the following step S19.

If the determination in step S15 is NO and the pressure drop has not occurred, the process proceeds to step S20, in which it is determined whether or not a predetermined time (for example, 15 minutes) has elapsed since the shutoff valve 17 was shut off. If has passed, the process proceeds to step S21, where it is determined that the minute gas leakage has not occurred. After that, the process proceeds to step S22, and the result determined here in step S21 is stored in the memory device 32b together with the time data at that time. After that, the process proceeds to step S28, and the center 11 is notified that there is no minute gas leakage determined in step S21.

Then, the process proceeds to step S23, where it is determined whether or not the return request signal from the center 11 requesting the return of the shutoff valve 17 is input. NO in step S23
If the return request signal is not input in step S24, the process proceeds to step S24, where it is determined whether the shutoff valve opening / closing switch 32d has been operated to open. This step S24 is provided to cope with the fact that the gas is used after opening the shut-off valve that is normally shut off when the tenant or the like closes the store.

When it is determined in step S23 that the return request signal is input, or when the shutoff valve opening operation is determined in step S24, the shutoff valve 17 is returned to the open state in step S25. And then step S26
Check whether or not the return safety confirmation is OK.
This determination is performed by detecting the pressure of the gas pipe 20 within a predetermined time (for example, 20 seconds, 1 minute, 2 minutes). That is, immediately after the shutoff valve returns, the gas appliance 19 at the end is not used, so if the pressure is normal, the pressure does not drop,
If there is a gas leak, the pressure will drop. Therefore, it is judged by judging such a state. If the determination in step S26 is NO and the return safety confirmation is not OK, step S2
7, the shutoff valve 17 is shut off again to stop the gas supply, and the process returns to step S23. If the return safety confirmation in step S26 is OK, proceed to step S19 and display 32c
Is turned off to notify the end of the inspection.

In step S17 and step S22, the memory device 32
The judgment result and the inspection time data stored in b are sent to the center 11 as needed. For this reason, the control unit 32a
Perform the tasks shown in the flowchart of FIG. In the flowchart of FIG. 5, the control unit 32a first determines in step S31 whether or not the signal requesting the inspection result from the center 11 is input. If the determination is YES and the request signal is input, the control unit 32a determines in step S32. Then, the inspection results stored in the memory device 32b a predetermined number of times (for example, three times) in the past are sent to the center 11. The center 11 considers this inspection result and takes necessary measures.

Although the gas leak is detected by detecting the pressure of the gas pipe 20 in the above embodiment, it may be detected by other means.

Further, in the above-mentioned embodiment, the gas meter 16 and the shutoff valve 17 having the pressure sensor built therein are shown as separate components, but as shown in FIG. 6, both the pressure sensor and the shutoff valve are built-in. The gas meter 33 may be used.

[Effect]

As described above, according to the present invention, a shutoff request signal for shutting off the shutoff valve is sent from a remote center at any time to each of a large number of terminals connected to the center via a communication line. In response to this, a gas leak test is performed at the terminal, the test result is reported to the center and stored in the terminal, and when the reported test result indicates that there is no minute gas leak, the shutoff valve shut off from the center is returned to the open state. In response to this, a return request signal is sent, the shutoff valve is returned to the open state at the terminal, safety check is performed when the shutoff valve returns, and only when the safety check can be made, the gas can be used thereafter. Therefore, it is possible to safely and efficiently perform the minute gas leakage inspection, and it is not necessary for the inspector to visit the gas user's house every time the gas leakage inspection is performed, and the inspection cost can be significantly reduced.

In addition, a result request signal for notifying the center of the stored inspection result is sent to each of a large number of terminals from time to time, and in response to this, a predetermined number of inspection results stored in the terminal are read and the center is notified. Therefore, when it is necessary for the center to judge the latest inspection result, it is possible to obtain a predetermined number of past inspection results for reference.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a gas leakage inspection system according to the present invention, FIG. 2 is a block diagram showing an embodiment of a gas leakage inspection system according to the present invention, and FIG. 3 is a part of FIG. FIG. 4 is a block diagram showing details, FIG. 4 and FIG. 5 are flow charts showing work performed by the control unit of the terminal control device shown in FIG. 2, and FIG. 6 is a diagram showing a modification of a part of FIG. FIG. 7 is a block diagram showing an example of the configuration of a conventional system, and FIG. 8 is a flowchart showing the work performed by the control unit of the terminal control device in FIG. 11 ... Center, 11a ... Shutdown request signal transmitting means, 11b ...
… Return request signal sending means, 11c …… Result request signal sending means, 17 …… Shutdown valve, 20 …… Gas flow path, 32a ₁ …… Shutdown valve shutoff means (control section), 32a ₂ …… Small gas leak inspection Means (control unit), 32a ₃ ... Leakage reporting means (control unit), 32a ₄ ... Shut-off valve resetting means (control unit), 32a ₅ ... Return safety confirmation means (control unit), 32a ₆ ... Report result Means (control section), 32b ...
... storage means (memory device), L ... communication line.

Claims (1)

[Claims] 1. A center and a large number of terminals are connected by a communication line, a shutoff valve provided in a gas flow path is shut off, and a minute gas leak occurring in a gas pipe from the shutoff valve to a gas device is inspected.
In a gas leakage inspection system that reports this inspection result to the center, a disconnection request signal transmitting means is provided in the center for transmitting a disconnection request signal for disconnecting the isolation valve to each terminal via a communication line, and to each terminal. Shut-off valve shut-off means for shutting off the shut-off valve based on the shut-off request signal input from the shut-off request signal sending means through a communication line A minute gas leakage inspection means for inspecting a minute gas leakage in the gas pipe from the shutoff valve to the gas equipment when the valve is shut off, and the inspection result of the minute gas leakage by the minute gas leakage inspection means provided in each terminal is stored. Storage means and a leak communication provided in each terminal for notifying the center of the inspection result of the minute gas leakage by the minute gas leakage inspection means via the communication line. Means, and a return request signal sending means for sending a return request signal for returning the open state of the shut-off valve to the terminal, which is provided in the center and has been informed of the inspection result, through the communication line. Shut-off valve restoring means provided in each terminal for receiving a restoration request signal from the restoration request signal sending means through a communication line and restoring the shut-off valve to an open state based on the inputted restoration request signal, A safety check is performed by monitoring the pressure drop in the gas pipe from the shut-off valve provided in the terminal and opened by the shut-off valve resetting means to the gas equipment, and when the safety cannot be confirmed, the shut-off valve is shut off again. Safety confirmation means and result request signal transmission for transmitting a result request signal, which is provided in the center and requests a predetermined number of inspection results stored in the storage means, through a communication line. Means and each terminal, the result request signal from the result request signal sending means is input through the communication line, and the inspection result for a predetermined number of times stored in the storage means is based on the input result request signal. A gas leakage inspection system, comprising: a result reporting unit that reads out and reports the read out inspection result to the center.