JPH0325333A - Gas leakage inspection system - Google Patents

Abstract

PURPOSE:To eliminate the need for visiting a gas user house every time inspection is performed by connecting many terminals to a center by communication channels, sending cutoff request signals for cutoff valves of the terminals out of the center at a distance at any time, and informing the center of the detection result of a minute gas leakage according to the requesting signals. CONSTITUTION:When a cutoff requesting signal input means 32a1 inputs a cutoff requesting signal sent from the cutoff requesting signal sending means 11a of the center 11 through a communication channel L, a cutoff valve cutting- off means 32a2 cuts off the cutoff valve 17. At this time, gas is cut off in a gas pipe 20 from the cutoff means 17 to gas equipment 19. Here, when a minute gas leakage detecting means 32a3 detects a minute gas leakage in the gas pipe 20, an informing means 32a4 informs the center 11 of its detection result through the communication channel L. Therefore, the center 11 inspects the gas leakage at any time without sending an inspector to the gas user house where the gas equipment 19 is installed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention inspects minute gas leaks that occur in gas pipes from the shutoff valve that shuts off the gas flow path to the gas equipment, and reports the inspection results to the center. This relates to a gas leak inspection system.

[Prior Art] Conventionally, as the above-mentioned gas leakage inspection system, for example, LPG
A system is being considered in which centers and terminals are installed at distributors and LPG consumers, respectively.

FIG. 7 is a block diagram showing the general structure of this type of gas leak inspection system, in which l1 is the center, l2 is the center network control unit (C-NCU), and 13 and 14 are the subscribers. Line exchange, 15 is network control unit (NCU)
A terminal control device having a control unit 15a and a control unit 15b, 16
17 is a gas meter and a shutoff valve provided in the gas pipe 20 from the gas cylinder 18 to the gas equipment 19; 21 is an NC
It is a telephone connected to U15a, and the above terminal system ff
The f11 device 15, the gas meter 16, and the cutoff valve 17 constitute a terminal, and between the C-NCU 12 and the subscriber line exchange 13,
Between subscriber line exchanges 13 and 14 and subscriber line exchange 1
4 and the terminal control device 115 are connected by a communication liner L.

In the illustrated system, the control unit 15b of the terminal control device 15 has a built-in switch that manually opens and closes the cutoff valve l7, and when the cutoff valve l7 is closed, the cutoff valve l7 is connected to a gas pipe 2 buried underground on the downstream side. It has a built-in pressure sensor that detects gas pressure.

In the above structure, the control unit 15 of the terminal control device 15
b performs the work shown in the flowchart of FIG. 8 according to a predetermined program. The illustrated flowchart starts in response to the operation of the cutoff valve closing switch of the control section 15b, and a cutoff signal is output to the cutoff valve 17 in the first step S1. After that, the process proceeds to step S2, where the state of the pressure switch inside the shutoff valve 17 is monitored and the gas pipe 2
Determine whether there is a drop in pressure within 0. If there is a decrease in pressure and the determination in step S2 is YES, the process proceeds to step S3, where it is determined that there is a slight gas leak, and in the subsequent step S4, the center 11 is notified of this, and the execution of the flowchart ends. do.

If the determination in step S2 is NO and there is no decrease in pressure, the process proceeds to step S5, where it is determined whether 15 minutes have elapsed since the shutoff of the shutoff valve 17, and until the determination in step S2 becomes YES, step S2 And the determination in step S5 is repeatedly executed. If the determination in step S5 is YES, that is, there is no decrease in pressure even after 15 minutes, step S
6, it is determined that there is no slight gas leakage, and in the subsequent step S7, a signal is output to close the shutoff valve 17 in response to the operation of the shutoff valve open switch of the control unit 15b, and the shutoff valve is returned to its original state. Terminates execution.

The center 11 that received the above-mentioned notification notifies the gas user at the terminal by telephone, and then closes the shutoff valve 17 or gas meter 1.
6, have a built-in shutoff valve installed, or have a gas distributor visit the terminal from the center and shut it off themselves.

[Problems to be Solved by the Invention] In the conventional system described above, each terminal is inspected for minute gas leaks, and only when there is an abnormality, it is possible to report the fact to the center l1.

However, recently, there has been an increase in gas leak accidents from buried parts of gas pipes, and gas distributors are now required to keep records of the presence or absence of minute gas leaks at regular intervals. ing. However, in the above system, in order to record that there are no abnormalities, a person from the gas distributor must go to each gas user's home 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 gas pipes for minute gas leaks, which placed an extremely heavy burden on the contractor.

Therefore, it is an object of the present invention to provide a gas leakage inspection system that allows a gas leakage inspection of a gas pipe to be carried out without the need for a contractor to visit a gas user's home.

[Means for Solving the Problems] In order to solve the above problems, the gas leakage inspection system according to the present invention connects a center 11 and a large number of terminals to a communication line L, as shown in the basic structure diagram of FIG. the gas pipe 20 from the shutoff valve 17 to the gas equipment 19 is inspected for minute gas leaks, and the inspection results are reported to the center 11. In the gas leakage inspection system, a cutoff request signal sending means 11a is provided at the center 11 and sends a cutoff request signal to the communication line to cut off the cutoff valve 17 to the terminal, and a cutoff request signal sending means is provided at the terminal and said cutoff request signal sending means 11a through the communication line L; , a cutoff valve cutoff means 32a2 that cuts off the cutoff valve l7 based on the cutoff request signal inputted by the cutoff request signal input means 32a1; A micro gas leak detection means 32a3 for detecting a micro gas leak in the gas pipe 20, and a reporting means 32a4 for reporting the detection result of the micro gas leak by the micro gas leak detection stage 32a to the center l1 via the communication line L. It is characterized by having the following.

[For production]

In the above structure, the communication line L. Through Center 11
When the cutoff request signal input means 32a+ inputs the cutoff request signal sent from the cutoff request signal sending means 11a, the cutoff valve cutoff means 32a2 cuts off the cutoff valve l7, and when the cutoff valve 17 is cut off, the minute gas Leakage detection stage 32a
3 detects a minute gas leak in the gas pipe 20 from the shutoff valve 17 to the gas equipment 19, and reports the detection result.
2a4 notifies the center 11 via the communication line L.

Therefore, the center 11 can inspect gas leakage at each terminal at any time.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a block diagram showing an embodiment of the gas leakage inspection system according to the present invention, in which parts equivalent to those of the conventional system described above with reference to FIG. 7 are given the same reference numerals. In FIG. 2, 30 is a no-ringing trunk (NRT) attached to the subscriber line exchange l4.
, 3 1 is a terminal network control unit (ANR-NCU) , 3
2 is a terminal control device from which the ANRNCU 31 is taken out.

The center 1l is installed at an appropriate location of an LPG distributor, for example, and a terminal is installed at each of a large number of gas consumption destinations (only one terminal is shown in the figure, but in reality there are many terminals). ) has a function that can output a shutoff request signal requesting the shutoff valve to be shut off at any time. The C-NCU 12 is connected to the center 11 via n signal lines and is attached to the center 11, and performs time-sure communication control between the center 11 and a large number of terminals on the center 11 side. Do it in a ring.

The subscriber line exchanges 13 and 14 are installed at the telephone office closest to the center 11 and the terminals, and perform telephone exchange operations between the center 11 and the terminals based on the telephone number issued when a call is made from one to the other.

In particular, since the terminal side also uses the communication line L for subscriber telephones, the subscriber line exchange 14 is equipped with NRT30 so that calls from the center 11 can be received without ringing the telephone bell. It is connected. In addition, Center 11
Since the communication line L is not used with a telephone on the side, the NRT is not connected to the subscriber line exchange 13.

ANR-NCU3 1 is used to connect the terminal to the communication line L when there is an incoming call based on the call from the center 11 or when there is a call from the terminal. Installed at gas users' homes.

The terminal control device 32 is operated by a CPU that operates according to a predetermined program as shown in FIG. It has a control section 32a, and a memory device 32b1 display 32c and a cutoff valve opening/closing switch 32d connected to the control section 32a, respectively.

In the above arrangement, the inspection operation for minute gas leaks performed by the control section 32a will be explained with reference to the flowchart of FIG. Flowchart 1: The work shown in the figure is performed by the control unit 32.
The process starts when power is turned on to a, and in the first step 311, it is determined whether or not a cutoff request signal has been input from the center 11 through the NRT 30. At this time, the operator of the center 11 notifies each end gas user's home in advance that the gas will be temporarily unavailable because the shutoff valve 17 will be shut off.

If the determination in step S11 is No and the cutoff request signal has not been input, the process advances to step S12, where it is determined whether or not the cutoff valve 17 has been closed by operating the cutoff valve open/close switch 32d. judge. If the determination in step S12 is NO and the shutoff valve closing operation is not performed, the process returns to step S311. The cutoff request signal is input in step 311, or step 31
When it is determined in step 2 that the shutoff valve is closed,
The process proceeds to the gas leakage inspection operation after step 313. In addition,
The above step S12 is for performing a gas leakage inspection even when the gas user is a tenant or the like and manually closes the shutoff valve at the time of closing and returns home.

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

Next, the process proceeds to step S14, where the display 32C is turned on to inform the gas user that the inspection is being carried out. After that, the process proceeds to step 315, where the output of the pressure sensor built in the shutoff valve l7 is monitored, and based on the output of the pressure sensor, it is determined whether the pressure in the gas pipe 20 from the shutoff valve 17 to the gas equipment 19 has decreased. Determine. Above step S15
If the determination is YES and the pressure has decreased, step 316
At this point, it is determined that a small gas leak has occurred. Next, the process proceeds to step S17, where the step 31 described above is performed.
The results of the determination in step 6 and data regarding the time at that time are stored in the memory device 12b. Then proceed to step 318,
Here, this minute gas leakage information is reported to the center 11 through the ANR-NCU 31 to NCU 12, and in the subsequent step S19, the display on the display 32c is turned off.

If the determination in step Sl5 is NO and no pressure drop has occurred, the process proceeds to step 320, where it is determined whether a predetermined time (for example, 15 minutes) has elapsed since the shutoff of the shutoff valve l7, and if the determination is YES, the time has elapsed. If has passed, step 3
The process proceeds to step 21, where it is determined that no minute gas leak has occurred. The process then proceeds to step S22, where the result determined in step S21 is stored in the memory device 32b together with the time data at that time. Then proceed to step
The center 11 is notified that there is no slight gas leak determined in step 321.

The process then proceeds to step S23, where it is determined whether a return request signal from the center 11 requesting that the shutoff valve 17 be returned is input. If the determination in step 323 is No and the return request signal has not been input, the process proceeds to step S24, where it is determined whether or not the shutoff valve opening/closing switch 32d has been operated to open. This step S2
4 is provided in order to cope with the fact that gas is used after opening the shutoff valve, which is normally shut off, when a tenant closes the store.

If it is determined in step S23 that a return request signal is input, or if it is determined in step S24 that the cutoff valve is opened, the cutoff valve 17 is returned to the open state in step 325. Then, in step S26, it is determined whether the return safety confirmation is OK.

This determination is made by detecting the pressure in the gas pipe 20 within a predetermined period of time (for example, 20 seconds, 1 minute, or 2 minutes). In other words, immediately after the shutoff valve returns, the terminal gas appliance l9
Since it is not in use, there will be no pressure drop if it is normal, but if there is a gas leak, the pressure will drop.
The determination is made by determining such a state. If the determination in step S26 is NO and the complete return confirmation is not OK, the process proceeds to step 327, where the shutoff valve 17 is again
is shut off to stop the gas supply, and the process returns to step 323 above. If the return safety confirmation in step S26 is OK, the process proceeds to step S19, where the display 32c is turned off to notify the end of the inspection.

The judgment results and inspection time data stored in the memory device 32b in step 317 and step S22 are as follows:
It is sent to the center 11 as necessary. For this purpose, the control section 32a performs the work shown in the flowchart of FIG. In the flowchart of FIG. 5, the control unit 32a first determines in step S31 whether or not a signal requesting test results from the center 11 has been input, and the determination is YES.
If the request signal is input in step S, the process advances to step S32, where the test results of a predetermined number of times (for example, three times) in the past stored in the memory device 3 2 b are sent to the center 11. Center 11 will review the test results and take necessary measures.

Although gas leakage is detected by detecting the pressure of the gas pipe 20 in the above-mentioned example of a power tank, other means may be used to detect the gas leakage.

Furthermore, in the above-mentioned embodiment, the gas meter 16 and the cutoff valve 17 that housed the pressure sensor were constructed separately, but as shown in FIG. A built-in gas meter 33 may also be used.

〔effect〕

As explained above, according to the present invention, a cut-off request signal is sent from a remote center at any time to request a cut-off to cut off the cut-off valve of a terminal in order to perform a gas leak test, and the terminal responds to the request for a cut-off request signal to shut off the cut-off valve of the terminal. We are making it possible to conduct inspections.
There is no need to go to the gas user's home each time an inspection is performed, and inspection costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic rules of the gas leak inspection system according to the present invention, Fig. 2 is a block diagram showing an embodiment of the gas leak inspection system according to the present invention, and Fig. 3 is a portion of Fig. 2. FIGS. 4 and 5 are flowcharts showing the work performed by the control unit of the terminal control device in FIG. 2, and FIG. 6 is a modification of a portion of FIG. 2. 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 section of the terminal control device in FIG. 7. 1l...Center 11a...Shutoff request signal sending means, 17...Shutoff valve, l9...Gas equipment, 20...
- Gas pipe, 32a. ... Cutoff request signal input means, 32
a2 Shutoff valve shutoff means, 32a, . . . minute gas leak detection means, 32a4 . . . reporting means, L . . . communication line. 32d 32c 32b Figure 5 Manual Mistake Ewa It Original (self-published) October 6, 1999

Claims (1)

[Claims] A center and a number of terminals are connected through communication lines, a cutoff valve provided in a gas flow path is cut off, and minute gas leaks occurring in gas pipes from the cutoff valve to gas equipment are inspected, In the gas leakage inspection system that reports the inspection results to the center, a cutoff request signal sending means is provided at the center and sends a cutoff request signal to the communication line to cut off the cutoff valve to the terminal; a cutoff request signal input means for inputting a cutoff request signal from the cutoff request signal sending means through a communication line; a cutoff valve cutoff means for cutting off the cutoff valve based on the cutoff request signal input by the cutoff request signal input means; a minute gas leak detection means for detecting a minute gas leak in a gas pipe from the shutoff valve to the gas equipment when the shutoff valve is shut off; and a minute gas leakage detection result by the minute gas leakage detection means sent to a center via a communication line. A gas leak inspection system characterized by comprising: a reporting means for reporting.