JPS605892B2 - Pipe rupture detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe rupture detection device in a system in which water is distributed from a water reservoir such as a water distribution reservoir or an elevated tank to a demand end.

BACKGROUND ART Conventionally, there have been many water supply systems in which a water distribution reservoir is installed in a high place, for example, halfway up a mountain, and water is pumped up using a pump, and water is supplied to a water distribution network by utilizing the pressure difference caused by the difference in height. However, the method for detecting rupture in pipes from the subordinate water distribution reservoir to the distribution network is to find the rate of change in flow rate at each predetermined period, and then compare the rate of change in flow rate within the latest predetermined period with the previous rate of flow change to determine the difference. This is a method of detecting pipe rupture when this difference exceeds a predetermined value. According to this method, rapid rupture, in which the pipe ruptures rapidly due to impact, can be detected, but rapid rupture cannot be detected. Slow rupture occurs when piping that has deteriorated over time develops a crack, which gradually grows until it finally ruptures. Therefore, in order to prevent slow rupture, it is necessary to take appropriate measures at the stage when water leaks from pipes due to cracks, etc., and conventional methods have not been able to prevent slow rupture. The aim of the invention is to eliminate these drawbacks and
An object of the present invention is to provide a pipe rupture detection device that detects rupture, especially slow rupture, by detecting only the flow rate signal discharged from a water storage part.

In order to achieve this objective, the present invention detects the flow rate of the liquid in the piping with a flow rate detector, calculates the rate of change in flow rate within a predetermined cycle at each predetermined cycle, and uses the rate of change in flow rate during the current cycle to calculate the following: This is done by calculating the predicted instantaneous flow rate for a predetermined cycle, comparing it with the actual instantaneous flow rate for the next predetermined cycle, and detecting a pipe rupture when this difference exceeds a predetermined value.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a case where an embodiment of the present invention is applied to a water supply system, in which a pump (not shown) pumps a liquid, such as water, to a water storage unit, such as a water distribution reservoir 1, and supplies water to a water distribution network (not shown) through piping 2. The water distribution reservoir 1 is usually provided at a high place such as the top of a mountain. In order to detect this rupture of the pipe 2, a flow rate detector 3 for detecting the flow rate in the pipe 2 is provided near the distribution reservoir 1 of the pipe 2. This flow rate signal from the flow rate detector 3 is applied to a storage circuit 4. Further, in order to store the flow rate signal from the flow rate detector 3 in the storage circuit 4 at predetermined intervals, a reference period signal generator 5 is provided and the reference period signal is sent to the storage circuit 4 via the arithmetic control section 6. Further, the flow rate signal from the storage circuit 4 is applied to the rate of change calculation circuit 7 at predetermined intervals, and the rate of change at each predetermined cycle is calculated from the flow rate signal and stored in the storage circuit 8. A flow rate calculation circuit 9 is provided which calculates the expected instantaneous flow rate during the next cycle based on the rate of change with respect to the current cycle from the storage circuit 8. These rate-of-change calculation circuits 7 and flow rate calculation circuits 9 are controlled by the calculation control unit 6.The amount of water consumed at different times of the day can be statistically predicted as shown in Figure 2, and the amount of water consumed is generated based on this statistics. A reference flow rate signal generator 10 is provided.Furthermore, the measured flow rate signal from the flow rate detector 3 is compared with the predicted instantaneous flow rate signal from the flow rate calculation circuit 9, and when this difference exceeds a predetermined value, it is determined that there is a rupture. Judgment circuit 1
1 will be provided. This scheduled value is a predetermined value that is predetermined according to changes in water consumption based on statistics. When the rate of change calculation circuit 7 receives a reference periodic signal from the periodic signal generator 5 with a sampling period T, the time UTn-, and the time Tn(Tn-Tn-,=
Flow rate signal F from the flow rate detector 3 during sample period T)
By (Tn-,), F(Tn), FQn)-壬(Tn
-2(:Q) to find the rate of change Q.

This rate of change Q is then sent to the flow rate calculation circuit 9. This flow rate calculation circuit 9 operates in the following cycles, that is, time Tn and time Tn0,
The expected flow rate signal during this period is calculated in relation to time t (Tn≦t≦Tn+,). This expected flow rate signal (t) =
t + F (Tn) = F (Tn) + {Fnn) - Main RTn
−J}Xt.

Therefore, in the determination circuit 11, when the time reaches during the next cycle, that is, when the time t becomes TnmitSTn+, the actual measured flow rate F(t) of the flow rate detector 3 and the predicted flow rate from the flow rate calculation circuit 9 are determined. Compare the signal fn(t) and get F(Tn)-m(
When t)=8 and 8 becomes larger than the scheduled value based on the reference water consumption from the reference flow rate signal generator 10, the determination circuit 11 determines that there is a rupture. As described above, according to the present invention, the flow rate of the liquid in the piping is detected by the flow rate detector, and the rate of change in the flow rate within the predetermined period is calculated by the change rate calculation circuit at each predetermined period.
The flow rate calculation circuit calculates the predicted instantaneous flow rate for the next predetermined cycle based on the flow rate change rate during the current cycle, and the predicted instantaneous flow rate and the
The determination circuit compares the measured instantaneous flow rate during the next predetermined cycle,
Since a pipe rupture is detected when this difference becomes larger than a predetermined value based on the reference water consumption amount from the reference flow rate signal generator, it is possible to accurately detect a slow rupture of the pipe.

In other words, in the present invention, even within a predetermined period, the predicted instantaneous flow rate is obtained from time to time and compared with the measured instantaneous flow rate, and the actual measured instantaneous flow rate and the predicted instantaneous flow rate are calculated based on the scheduled value based on the reference water consumption amount from the reference flow rate signal generator. Since it is determined that the difference with the flow rate becomes large, even minute changes in flow rate can be detected, so not only rapid rupture but also slow rupture can be detected. It also has the effect of being able to detect pipe rupture using only the flow rate signal. Further, the present invention may be implemented by being configured with an electronic computer or a microcomputer, and the reference flow rate signal may be controlled by the season, temperature, weather, etc.
It may be changed depending on the day of the week, etc.

[Brief explanation of drawings]

Fig. 1 is a block diagram when an embodiment of the present invention is applied to water supply, Fig. 2 is a diagram illustrating consumption flow rate with respect to time, and Fig. 3 is a diagram illustrating the operation of the embodiment of Fig. 1. be. 1...Water reservoir, 2...Piping, 3...Flow rate detector. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A device for detecting rupture of a pipe that guides liquid discharged from a water storage section, including a flow rate detector that detects the flow rate of the liquid in the pipe, and a rate-of-change calculation that calculates the rate of change in flow rate within a predetermined period at each predetermined period. a flow rate calculation circuit that calculates the predicted instantaneous flow rate at each moment in the next predetermined cycle based on the flow rate change rate output during the current cycle of this change rate calculation circuit; and a reference flow rate that generates a standard consumption flow signal based on statistics. A signal generator compares the output of the flow rate calculation circuit with the actually measured instantaneous flow rate during the next predetermined cycle, and when this difference exceeds a scheduled value based on the reference consumption flow signal of the reference flow rate signal generator. A pipe rupture detection device comprising: a determination circuit for detecting a rupture of the pipe.