JPH0149886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a water distribution reservoir plant having an inflow side pipe and an outflow side pipe, and furthermore, the fluctuation of the outflow flow rate according to time of day repeats almost the same pattern every day. This relates to a method for monitoring the presence or absence of abnormalities (specifically, water leakage due to pipe breakage, etc.) in the outflow pipes of water distribution reservoirs.

FIG. 1 is a block diagram showing a conventional monitoring and control system for a water supply reservoir plant. In the same figure,
1 is a water distribution reservoir, 2 is an inflow pipe, 3 is an outflow pipe, 4 is a water level gauge, 5 is an inflow flowmeter, 6 is an outflow flowmeter, 7 is a monitoring control device, 8 is an input storage device, 11 is a setting storage device, 12 is a setting comparison device, 15 is an operator console, and 16 is a display device.

In FIG. 1, the monitoring and control device 7 monitors the water distribution reservoir water level L(t) (t represents time and indicates that the water level L is a function of time t. The same applies hereinafter) to the water level gauge 4 and the inflow amount Q. _I (t) and outflow amount Q _O (t) are input from the flowmeters 5 and 6, respectively, and the inputs are stored in the input storage device 8 as input information. The monitoring control device 7 also receives upper limit monitoring set values LH, Q _I H, Q _O H and lower limit monitoring set values LL, Q _I regarding the above input information that the operator sets from the operator console 15.
L, Q _O L, setting value for fluctuation rate monitoring LD, Q _I D, Q _O D
is stored in the setting storage device 11.

Here, the monitoring control device 7 monitors the water distribution reservoir water level L
(t), inflow quantity Q _I (t), and outflow quantity Q _O (t) are set and compared with the monitoring set values for each of the input information to perform upper limit monitoring, lower limit monitoring, and fluctuation rate monitoring. Comparison device 12 The comparison device 1
2 is determined to be abnormal, an upper limit alarm, a lower limit alarm, and a fluctuation rate alarm are output to the display device 16. However, such conventional monitoring and control systems have the following drawbacks.

In other words, the water level in the reservoir L(t), the inflow _QI (t),
It only monitors individual fluctuations such as the outflow amount Q _O (t), and does not monitor the interrelationship of these fluctuations, so abnormalities in the outflow pipe (water leakage due to pipe breakage, etc.) cannot be detected. . The operator monitors the interrelationships of individual fluctuations in water level, inflow, and outflow, and determines whether or not there is an abnormality in the outflow pipe based on the monitoring results. Since these conditions vary widely, the time it takes to detect an abnormality depends on the operator's level of experience, and in the worst case, an abnormality cannot be detected, leading to accidents such as water outages at customers.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and therefore, an object of the present invention is to correct abnormalities in the outflow side pipes of water distribution reservoir plants.
It is an object of the present invention to provide a monitoring system for an outflow side pipe of a water distribution reservoir plant that can automatically and accurately detect it at an early stage without relying on an operator.

The main points of the present invention are as follows. First, the average outflow flow rate per unit time for each time period obtained from the outflow amount actual values over a certain period of time in the outflow side pipe is memorized, and the measured outflow flow rate value per unit time at a certain time and the outflow flow rate value per unit time are stored. The stored average outflow flow rate value per unit time of the corresponding time zone including the relevant time is compared, and if the former is greater than the latter by more than a certain limit, it is first determined that there is an abnormality. Next, at the time when it is determined that there is an abnormality, the inflow and outflow flow rates in the distribution reservoir per a certain time are measured, and the fluctuation in the distribution reservoir water amount calculated from the difference between them and the water level in the distribution reservoir at the same time are calculated. Measure the fluctuation and compare it with the fluctuation in the water distribution reservoir water amount obtained by multiplying the amount of fluctuation by the bottom area of the reservoir, and if the two are almost the same, it is determined that water leakage has occurred due to damage in the outflow pipe. However, the key point of the present invention is that if there is a difference between the two exceeding a certain limit, it is determined that a failure has occurred in the flow rate measuring instrument installed in the outflow side pipe.

Add some explanation. In the present invention, an abnormality in the outflow side pipe is determined based on the following two conditions.

The water level gauge and flow meter installed in the inlet pipe are assumed to be normal.

Fluctuations in the flow rate by time of day repeat in almost the same pattern every day.

The conditions are based on the judgment that the probability that the flow meter installed on the outflow side pipe and the flow meter or water level meter installed on the inflow side pipe will be in a failure state at the same time is extremely low. It is.

Assuming these two conditions, regardless of the above-mentioned conditions, if the outflow flow rate deviates from the same pattern by more than a certain limit, it can be determined that there is an abnormality. When an abnormality is determined in this way, there are two possible causes of the abnormality.

(a) Outflow volume has increased due to damage to the outflow pipe.

(b) The flowmeter installed in the outflow pipe is malfunctioning.

The next step is to determine which of these two causes caused the previous abnormality. Based on the above-mentioned conditions, the arrangement determined from the measured inflow flow rate and outflow flow rate is determined. Compare the fluctuations in the water reservoir water level with the fluctuations in the water distribution reservoir water level actually measured by the water level meter. (a) If the two fluctuations match, it means that the inflow flow rate is actually increasing, so there is no outflow. The side pipe is damaged (b) If the two fluctuations do not match, it is determined that the flowmeter installed in the outflow pipe is malfunctioning.

Abnormalities that cannot be monitored by the present invention include damage to the outflow pipe, a water level gauge that is out of order, or failure of either of the flow meters installed in the inflow and outflow pipes. Because of this, there is a possibility that the two fluctuations will not match, and it may not be possible to determine whether the outflow pipe is damaged, but it is extremely unlikely that pipe damage and instrumentation failure will occur at the same time. The discrimination according to the present invention can be sufficiently put to practical use.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing one embodiment of the present invention. In the same figure, the same reference numerals as in FIG. 1 indicate equivalent parts. In addition, 9 is a time storage device, 10 is a weekly storage device, 13 is an average comparison device,
14 is a balance comparison device.

For convenience of explanation below, it is defined as follows. In other words, a day is equally divided into multiple time periods of a predetermined time (therefore, if the predetermined time is set as one hour, there are 24 time periods), each time period is expressed as h, and data is measured at regular intervals, for example, every minute. A certain current time is expressed as t, and the break time of the time zone h and the current time t are synchronized.

In FIG. 2, the monitoring and control device 7 includes the water distribution reservoir 1
The water level L (t) is calculated using the water level meter 4, and the inflow amount Q _I (t) and outflow amount Q _O are calculated per unit time.
(t) is measured by the flowmeters 5 and 6, respectively, and taken in, for example, at a one-minute period, and stored in the input storage device 8 as input information, and the input information is transferred from the storage device 8 to the time storage device 9 and stored therein. At this time, the storage device 9 stores only information up to one hour before the current time t, and erases information before that. Furthermore, the monitoring and control device 7 calculates the outflow amount Q _O (t) converted per unit time, for example, 60
After continuous measurement, the average value is calculated and _Q
(h, T) and stored in the weekly storage device 10 as the average outflow flow rate value for that time period h of that day.

The weekly storage device 10 stores 24×7 average outflow flow values for each time period for the past week obtained as described above, and is updated from the oldest corresponding time period as the time period progresses. be done. Further, the operator stores the income and expenditure monitoring setting value A, the outflow monitoring setting value B, and the bottom area S of the water distribution reservoir set from the operator console 15 into the setting storage device 11 . For simplicity, the base area S is assumed to be constant regardless of the water level L, but if S
(L), a base area constant table for each water level L is required.

The procedure for monitoring the outflow side pipes of the water distribution reservoir plant, which is performed by the monitoring and control device 7, will be explained below.

First, in the first step, the average comparison device 13 calculates the outflow amount Q O (t) at the current time (assuming the current time zone is h) read from the input storage device 8 and the outflow amount Q _O (t) read from the weekly storage device 10. Outflow amount per hour Q _O (h, T) corresponding to the same time period h T days ago
The absolute value of the _difference ^from _{the corresponding} time period average value calculated over the past week using | is compared with the set value B for monitoring the outflow amount as a limit, and if |QOH−Q _O (t)|>B and the sign in the absolute value symbol is negative, that is, the outflow amount at the current time t. Average value of response time over the past week when Q _O (t) exceeds a certain limit B
When the QOH is exceeded, the balance comparison device 14 is notified of the abnormality occurrence signal EMG from the average comparison device 13.

Next, as a second step, the balance comparison device 14 that receives the abnormality occurrence signal EMG reads out the inflow and outflow data for the past hour with the current time t as a reference from the time storage device 9, and The integrated volume value PQ _I (t) and the integrated outflow value PQ _O (t) are calculated, and the water level data at the current time t and 1 hour ago with the current time t as a reference are also read from the storage device 9, and the water level data for the past 1 hour is calculated. Calculate the water level change ΔL in the middle, calculate PQ _I (t) − PQ _O (t) as the first balance result, and calculate ΔL×S using the water volume change in reservoir 1 as the second balance result. , compare these two income and expenditure results, which should be equal, and when the difference does not exceed the limit A set value for income and expenditure monitoring (|first income and expenditure result - second income and expenditure result|<A), that is, two When the two balance results are approximately equal, it is determined that a water leakage accident has occurred due to damage in the outflow pipe, and on the other hand,
When the difference obtained by comparing the two balance results exceeds the limit A, it is determined that a failure has occurred in the flowmeter 6 in the outflow pipe and normal measurement is no longer possible, and the display device 16 displays the respective results. Send and display an alarm signal depending on the case.

FIG. 3 is a block diagram showing another embodiment of the invention. The embodiment shown in the figure is an embodiment for a water distribution reservoir plant that has one inflow pipe and one outflow pipe, whereas the embodiment shown in Fig. 2 has n inflow pipes and one outflow pipe. This is an example for a water distribution reservoir plant having one reservoir plant and a plurality of reservoir plants, respectively.

In FIG. 3, 51 to 5n are inflow flowmeters provided in the inflow pipes 21 to 2n, respectively, and 61 to 6l are outflow flowmeters provided in the outflow pipes 31 to 3l, respectively.

Next, the procedure of the monitoring operation will be explained for the case where the outflow pipe 3l is monitored. First, as a first step, the average comparator 13 calculates the outflow amount Q _O l for the outflow pipe 3l at the current time read out from the input storage device 8.
(t) and the average value of the outflow amount for the outflow pipe 3l per hour in the current time period read from the weekly storage device 10 for the corresponding time period in the past week ₇ 〓 ^T=1 Q _Ol (h, T)/7 is determined by calculation, and the difference is compared with the monitoring setting value B _l . As a result, the amount of outflow at the current time exceeds a certain limit B _l
When the weekly average value is exceeded, average comparison device 1
3 sends an abnormality occurrence signal to the balance comparison device 14.

Next, in the second step, the balance comparison device 14 receives the abnormality signal EMG, and calculates the sum of the inflow amount from all inflow pipes and the sum of the outflow amount from all outflow pipes for the past hour from the data in the time storage device 9. The change ΔL in the water pond water level in the past hour is calculated, and the two income and expenditure results are obtained in the same manner as explained for the example shown in Fig. 2. By calculating the difference, the output side pipe Determine whether the 3l is damaged or the flow meter 6l is malfunctioning. Monitoring of other outflow side pipes is carried out in exactly the same manner.

According to this invention, instead of determining whether there is an abnormality in the outflow pipe of a water distribution reservoir plant, which had previously been done empirically by an operator, the monitoring and control device can collect information on the water level, inflow amount, and outflow amount of the water distribution reservoir. Since we decided to determine abnormalities in the outflow pipes based on their interrelationships, even if an abnormality occurs in the outflow pipes, it can be detected at an early stage. (2) The amount of water leakage can be minimized.

In the explanation of the embodiment, the information stored in the weekly storage device 10 was explained as being for the past one week.
This is not limited to one week, but may be any period as long as a period of appropriate length can be selected to draw and repeat the same pattern. Also, regarding the time storage device 9, information for the past one hour is not limited to one week. Of course, the time period is not limited to this, and may be any length of time suitable for the selected period.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional monitoring and control system for a water supply reservoir plant, FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a block diagram showing another embodiment of the present invention. It is. Explanation of symbols, 1... Water reservoir, 2... Inflow pipe, 3...
...Outflow pipe, 4...Water level gauge, 5...Inflow flow meter, 6
...Outflow flow meter, 7...Monitoring control device, 8...Input storage device, 9...Time storage device, 10...Weekly storage device, 11...Setting storage device, 12...Setting comparison device, 13... ... Average comparison device, 14 ... Income and expenditure comparison device, 15 ... Operator console, 16
...Display device.

Claims (1)

[Scope of Claims] 1. The above-mentioned outflow of a water distribution reservoir plant that has an inflow side pipe and an outflow side pipe, and the fluctuation of the outflow flow rate according to time in the outflow side pipe repeats in almost the same pattern every day. A system for monitoring the presence or absence of an abnormality in a side pipe, the method comprising: a means for storing an average outflow flow rate value per unit time for each time period obtained from the outflow amount actual value over a certain past period of the outflow side pipe; Comparing the outflow flow rate value per unit time at a certain time measured by the flow rate measurement means in the pipeline with the average outflow flow rate value per unit time of the corresponding time period read from the storage means. The first means of determining the presence or absence of an abnormality is to measure the inflow flow rate and outflow flow rate per certain time in the distribution reservoir, and calculate the fluctuation in the water volume of the distribution reservoir obtained from the difference and the water level fluctuation in the distribution reservoir during the same time. and a second means for determining differences by comparing the fluctuations in the water distribution reservoir water amount measured and obtained from the water level fluctuations, and when the first means determines that there is an abnormality, the second means determines whether there is an abnormality. A system for monitoring an outflow side pipe of a water distribution reservoir plant, characterized in that the means is activated to determine the difference, and based on the result, it is determined whether or not there is an abnormality in the outflow side pipe.