JPS6346320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects leaks and ruptures in supply piping networks for fluids such as water, gas, and oil, minimizes the damage, and minimizes the necessary treatment for fluids. It relates to supply piping network systems.

With the recent urbanization, fluid supply piping has been installed underground and inside buildings in a complicated manner to supply large quantities of water and gas, but if fluid leaks from this piping network, it can lead to a major accident. Often.

A burst water pipe caused a large amount of water to overflow onto the street for hours, flooding private homes, followed by water outages, and murky water.
Another example is an explosion caused by ignition of a gas leak from a gas pipe.

It is necessary to quickly and accurately know about fluid leaks and take appropriate treatment, and for this purpose, various research and developments are being conducted to detect fluid leaks.
It is still a step away from putting it into practical use.

For example, there are methods that detect leakage sounds and vibrations that occur when fluid leaks from piping, and methods that detect leakage when a difference in flow rate occurs between the supply side and the demand side. However, in the former case, it is difficult to distinguish between the sounds accompanying the opening and closing of faucets or pots during normal use or city noise (due to vibrations of automobiles, coolers, etc.) and leakage sounds and vibration sounds. In addition, the latter case is suitable for a pipeline with a single piping, etc., but in a complicated piping network, the supply side and the demand side do not correspond one-on-one, and it is also difficult to apply.

On the other hand, when a fluid leak is identified and its treatment and restoration are carried out, fluid supply must be completely cut off to a certain area, but sometimes this interruption extends to more areas than necessary. There is.

FIG. 1 is an example of a conventional fluid supply piping network diagram. If fluid leakage occurs at point 6 and 7 will have their fluid supply stopped.

It is an object of the present invention to supply fluid to consumers through duplicated piping that is commonly connected to each other and separated from each other on the consumer side, and to remove fluid from the piping due to the mutual difference in the physical quantity of the fluid flowing through the duplicated piping. By detecting leakage and closing the fluid shield valves installed before and after the leakage point, the leakage can be detected early and reliably, and the fluid supply stop range in the event of a leakage can be limited to a narrow range. An object of the present invention is to provide a fluid supply piping network system that is capable of providing fluid supply piping.

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

First, FIG. 2 is a system diagram of an embodiment of the fluid supply piping network of the present invention.

Source of fluid to the area to be applied 1
0, 11 to each end customer 5, 6, 7, 8, 9
All piping to each inlet of the system will be duplicated in parallel with piping for the A system and the system. In addition, at each branch point of the piping network, there are 10A shutoff valves for each A system and B system, respectively.
11A, 1A, 2A, 3A,..., 10B, 11
Leak detectors 10D, 11D, 1
Install D, 2D,...

Next, shutoff valves and leak detectors 5A, 5B, 5D; 6A, 6B, 6 are installed immediately before each end customer.
The details of the configuration of D; 7A, 7B, 7D; . . . will be explained with reference to the block diagram of FIG.

The part surrounded by the dashed line is the A system and B mentioned above.
This is a leak detector D installed so as to straddle the piping with the system, and its detailed configuration is as follows.

FA is a flowmeter installed downstream of the shutoff valve VA installed in the A system piping, and FB is installed downstream of the shutoff valve VB installed in the B system piping at the same branch point as the flow meter FA. It is a flow meter. These flow rates
Signals from FA and FB are sent to their respective electrical signal converters.
It is transmitted to the addition/subtraction calculator C via TA and TB, and the addition/subtraction calculator C calculates the flow rate difference between the A system and the B system, and the result is transmitted to the comparison calculator E. Comparison calculator E uses set values S, A system, and B that are given separately.
The difference in flow rate with the system is compared, and if the difference in flow rate becomes larger than the set value, an alarm signal is issued to the control station K, and a signal indicating that there is a leak is issued to the sequence control device G. The sequence control device G receives a leakage signal from the comparator E and closes both the A-system shutoff valve VA and the B-system shutoff valve VB.

Next, shutoff valves and leak detectors 1A, 1B, 1D; 2A, 2B, 2 are installed at the branch points of the main pipe.
The details of the configuration of D; 3A, 3B, 3D; . . . will be explained with reference to the block diagram of FIG.

The portion surrounded by the dashed line is the same as that in FIG. 3 described above. Comparison calculator E compares the flow rate difference between system A and system B with a separately given set value S and determines whether the set value has been exceeded on the positive side or the set value has been exceeded on the negative side, that is, on the A system side. Whether a leak has occurred on the B system side or on the B system side is communicated to the management station K through the data transmission slave station R. At the control station K, the result of comprehensive judgment based on such information from the entire controlled area is sent to the data transmission slave station R, and the sequence control device uses the signal of this comprehensive judgment result to control only the A system shutoff valve VA, or Close the B system shutoff valve VB or both shutoff valves.

Next, the operation of the embodiment shown in FIGS. 2, 3, and 4 will be explained.

First, a case will be described in which a leak occurs in the piping after branching to the consumer, assuming that the leak occurs at point Y of the A system to the consumer 5 in FIG. 2. In a state where there is no leakage, the output of the addition/subtraction calculator C in FIG. 3 is zero. This can be easily done by constructing the pipes so that the fluid resistance of the pipes is the same, or by applying a bias to the signal converters TA and TB to compensate for slight differences in flow rates.

Due to fluid leakage in the A system, the flow rate signal detected by the flow meter FA in the A system becomes larger than the flow signal detected by the flow meter FB in the B system, and the difference is converted into a positive electrical signal by the adder/subtractor C. The signal is transmitted to the comparator E as a signal. Comparison calculator E compares this transmitted flow rate difference with a set value S that has been separately given in advance, and if it exceeds the set value, it issues an alarm signal indicating the presence of a leak and sends a signal to sequence controller G. Generates pulse output.

In response to this pulse output, the sequence control device G closes both the A-system shutoff valve VA and the B-system shutoff valve VB. At this time, the consumer 5 is forced to temporarily supply fluid. On the other hand, due to the leakage at this Y point, for example, the leakage detector 1D upstream of the leakage detector 5D
Although leakage is detected in both cases, priority is given to closing the shutoff valves 5A and 5B due to the matters described later.
It is possible to prevent the shutoff valves 1A and 2A from closing due to leakage at the Y point.

Next, a description will be given of leakage in the main pipe assuming that the leakage occurs at point X of system B in FIG. Due to fluid leakage at point Compare the set value given by (This is the time required for the leak detector and shutoff valve on the downstream side to detect and close the fluid leakage, and is on the order of several tens of seconds). A signal is transmitted to the management station K via the data transmission slave station R, together with information indicating that there is leakage to the B system if it is on the positive side or the negative side, and to the A system if it is on the positive side.

At the control station K, if the above signal from the leak detector 1D or 2D is received, for example, a negative signal from the leak detector 1D, that is, a signal indicating that there is a leak in the B system, the data transmission slave stations at the key points 1 and 2 of the branch point are Shutoff valves 1B and 2B of each B system to R
A signal is issued to cause the valve to close.

Sequence control devices 1G and 2G at trunk branch points 1 and 2 control the cutoff valve 1 of each B system.
Close B and 2B. In this way, all paths that flowed into leak point X are blocked.

However, consumer 5, who is connected to this blocked main line,
6 and 7, the fluid supply from the B system is stopped, but the fluid supply from the A system continues, so although the fluid supply decreases quantitatively, the overall fluid supply continues.

On the other hand, the leak detector 10D at the branch point 10 on the upstream side of the branch point 1 similarly detects the leak at the point By also equipping the container 10D, the treatment method in the event of leakage can be carried out without adversely affecting a wider area than necessary.

Although the leak detector D in the above-mentioned embodiment was designed to detect a change in the flow rate of the piping due to a leak, it is applied and implemented in the present invention as a device that detects a pressure change in the piping due to a leak instead. be able to. The difference from the example is that in comparing the detection signals of system A and system B, in the case of flow rate detection, it was assumed that there was a leak in the system with the larger signal value, but in the case of pressure detection, the system with the smaller signal value was assumed to have a leak. Only if there is a leak.

As explained above, if the fluid supply piping network system according to the present invention is applied, the presence or absence of leakage can be determined based on signal differences such as the flow rate difference and pressure difference between the parallel duplex piping, so In either case, changes in the fluid in the pipes (flow rate changes, pressure changes, etc.) due to use by consumers or urban noise are canceled out, and only changes associated with leaks and ruptures can be detected, further improving detection accuracy. Moreover, there is no need for analysis means to extract signals buried in noise. Moreover, since the flow path to the leak point that has occurred is automatically blocked based on the detection result of the leak detector, it is possible to prevent a major accident from occurring.

Furthermore, by utilizing the advantage of parallel duplex piping in the fluid supply main line, leakage detection and treatment can be carried out without completely interrupting the supply to end users.
This can further reduce the negative impact by half even if the shutoff valve is closed due to malfunction of the leakage detector, and inconsistencies in the system can be avoided.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a conventional fluid supply piping network, FIG. 2 is a piping diagram showing an embodiment of the dual fluid supply piping network system of the present invention, and FIG. A detailed configuration diagram of a leak detector and a shutoff valve at each branch point to the end user of the pipe. FIG. 4 is a detailed configuration diagram of the leak detector and shutoff valve installed in the main pipe in this embodiment. 1, 2, 3, 4... main piping shutoff valve, 5,
6, 7, 8, 9... Piping network end user, 10, 1
1... Fluid supply source, A, B... Duplicate piping, 1
A, 2A, 3A,..., 1B, 2B, 3B...Shutoff valve, C...Adjustment calculator, D, 1D, 2D, 3D,
4D, 5D, 6D... Leak detector, F, E'... Comparison calculator, FA, FB, S... Flowmeter, G... Sequence control device, K... Management office, R... Data transmitter Bureau.

Claims (1)

[Claims] 1 Duplicated piping that is separated in parallel from the fluid supply source to the consumer side and commonly connected on the consumer side, and multiple duplex pipings from the consumer side of this duplex piping to the fluid supply source. Leak detectors are installed at different locations to detect leakage piping based on differences in physical quantities of fluid flowing through the duplex piping, and fluid detectors are installed in each piping of the duplex piping in correspondence with these leak detectors. a control device that inputs leakage information from each of the leakage detectors and gives a command to close the fluid shutoff valves before and after the piping where the leakage has occurred; A liquid supply piping network system configured such that the one installed closest to the consumer is controlled to be closed by a leak detection signal from a corresponding leak detector.