JP2001029937A - Apparatus for controlling intake of water purification plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of changes of the amount of water to be taken in corresponding to the change of water demand by measuring the amount of water to be distributed in a water distribution basin, averaging the values for a plurality of days to calculate the newest change with time, deciding a target water level, and then deciding a planned amount of water to be taken in to meet the target level. SOLUTION: The amount of water to be distributed is measured every constant time by a flow meter set in the water distribution passage 4, etc., of a water distribution basin 3, and measurement information is sent to the target water level/time zone decision block 10 of a water uptake control device 9. In the block 10, the change with time of the amount of water to be distributed in an average day is calculated, and the target water level of the basin 3 is decided, and information is sent to a block 11 for deciding the amount of water to be taken. In the block 11, a planned amount of water to be taken for a day is decided while a predicted water demand for a next day reported from a water demand predicting block 6 being considered. When the planned amount of water to be taken reaches a limit, the amount of water to be taken in is changed/controlled as required, and information is sent to a water level monitoring block 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water intake control device for a water purification plant that controls the water intake according to a planned water intake based on a prediction of water demand.

[0002]

2. Description of the Related Art Conventionally, a water purification plant is configured as shown in FIG. 4, and water intake such as river water in an intake channel 1 is sent to a distribution reservoir 3 through a water purification facility 2 having a sedimentation basin, a filtration basin and the like. Then, purified water is distributed from the distribution reservoir 3 to the distribution channel (water supply) 4.

[0003] The amount of water distribution varies depending on the demand for water. From the viewpoint of the stability of water purification treatment, it is desired that the amount of water intake be kept as constant as possible irrespective of changes in water demand.

Therefore, the water intake amount is conventionally controlled by a water intake control device 5 composed of a microcomputer or the like as described below.

[0005] First, a water demand prediction block 6 of the control device 5 executes a daily forecast under these conditions by a predetermined neural network operation based on weather forecasts such as clear rain, weather information such as temperature, and day information. For example, at time 0 am on the day, information (time-series information) of the predicted water demand A for each hour of the day is sent to the water amount determination block 7.

[0006] This decision block 7 comprises information on the predicted water demand A and the predetermined time-varying target water level h _O , upper limit water level h _H , lower limit water level h _L, and water intake uniform time zone Tw of the reservoir 3. Based on the information, for example, the planned water withdrawal amount B every hour of the day is determined.

The target water level h _O is a time-varying control target water level of the reservoir 3 based on the predicted water demand A. The upper limit water level h _H and the lower limit water level h _L are determined by the civil structure of the reservoir 3. It is an absolute water level that is decided.

[0008] Further, the water intake uniform time period Tw is a time zone in which the water intake is kept constant based on the planned water intake B, and specifically, at 1, 8:00, When the water intake is changed at 15:00, the water intake is changed from 1:00 to 8:00, 8:00 to 15:00, and 15:00 to exclude the change transition time. Unless corrections are made by reviewing B, the water intake will not change.

The planned water withdrawal B is calculated by the following (i),
The condition (ii) is satisfied and the reservoir 3 is set so as not to overflow. (I) The sum of the water intake in the water intake uniform time zone Tw is the water intake (water demand) in the time zone Tw based on the predicted water demand, and the water intake indicated by the water level change of the reservoir 3 during that time. It is almost equal to the sum of the difference between the amount of water and the amount of water distribution. (Ii) The time-varying predicted water level (reservoir predicted water level h _y ) of the reservoir 3 based on the difference between the water intake and the water distribution when operated at the planned water intake B is the upper limit water level h _{H at} all times.
To be a level between the lower limit level h _L.

Then, a valve, a pump, and the like for controlling the intake amount of the intake channel 1 are controlled by the intake amount determination block 7 in accordance with the planned intake amount B, and the intake amount at each time is adjusted.

At this time, the actual water demand is almost equal to the predicted water demand.
If the time changes according to the amount A, the water level of the reservoir 3 (actual
Water level) according to the target water level_H, Lower limit water
H _LChange appropriately, and systematically change the water intake
Water distribution without excess or shortage is performed.

On the other hand, if the actual water demand deviates from the predicted water demand A for some reason, the water level of the reservoir 3 fluctuates from the target water level.

At this time, if the water intake based on the initially planned water intake B is continued, the water level in the reservoir 3 greatly deviates from the target water level h _O and exceeds the upper limit water level h _H or falls below the lower water level h _L. Invite the situation.

[0014] Therefore, the water level of the distributing reservoir 3 in operation is measured with water gauge, the information of the measurement level h _x time varying is taken into the distributing reservoir water level monitoring block 8.

In addition, the water intake determining block 7 corresponds to the above-mentioned plan.
When determining the water intake B, at the same time, the predicted reservoir water level h_y
And the predicted reservoir water level h_yBased on
In addition, lower reservoir target upper water level h_yH, Reservoir target lower limit
Water level h_yLAnd the predicted water level h _yAnd target upper water level
h_yH, Target lower water level h_yLWater level monitoring
Supply to the hook 8.

The water level monitoring block 8 determines the measured water level h.
_xAnd the predicted water level h_y, Target upper limit water level h _yH, Target lower water level h
_yLBased on the above, monitor the water level abnormality of the reservoir 3 and
When the water is about to occur, the command C for reconsidering the water intake
Give to decision block 7.

At this time, the water intake amount determination block 7 determines the command C
Based on the above, the planned water intake B in operation is appropriately increased or decreased,
Even at a timing within the uniform water intake time period Tw, the control amount of the valve, the pump, and the like of the intake passage 1 is changed based on the corrected planned water intake amount B to change the water intake amount.

By the feedback control of the water intake,
Reservoir 3 has a target upper water level h _yH and a target lower water level h _yL
Is maintained at a normal water level, and water distribution is performed according to water demand.

[0019]

In the case of the water intake control of the conventional apparatus, when determining the planned water intake B, the target water level h _O , the upper limit water level h _H , and the lower water level h _{L of the} reservoir 3 are set in advance.
And information on the water intake uniform time zone Tw is used.

[0020] In this case, since the upper limit water level h _H, the lower limit level h _L is not affected by the water demand may be set once, it is not necessary to change depending on the season or the like, the target water level h _O and water intake uniform time zone Since Tw is affected by water demand, it is necessary to change it according to seasonal fluctuations of water distribution, etc., which are affected by water demand. If not properly changed, correction and change of water intake will be repeated during operation. Control stability is impaired.

However, conventionally, it is not possible to know the appropriate change time point and the change amount of the target water level h _O and the water intake uniform time period Tw.
Usually, the day of the season change is appropriately determined according to the operator's intuition or the like, and the target water level h _O and the water intake uniform time zone Tw are changed from spring setting to summer setting, for example.

Therefore, it is impossible to appropriately change the target water level h _O and the time zone Tw in which the water intake is uniform in accordance with the seasonal fluctuation of the water demand. As a result, there is a difference between the predicted and actual water level of the reservoir 3. easily occurs, during operation, measures the water level h _x is the target, the lower limit water level h _yH, easily departing from the scope of h _yL, each time, reviewing the command C is generated based on the monitoring of the water level monitoring block 8 abnormal Changes in water intake are repeated.

For this reason, although it is originally desirable to maintain the water intake amount as constant as possible to ensure the stability of the treatment in the water purification treatment facility 2, the water intake amount is frequently changed and the purified water to be distributed is distributed. Water quality is not stable, and water purification equipment 2
However, there is a problem that the load on the equipment in each of the above steps increases, and it is not possible to extend the life of the equipment.

An object of the present invention is to reduce the number of times of changing the amount of water withdrawal in response to seasonal fluctuations in water demand and to stabilize water quality and reduce the burden on purification equipment.

[0025]

In order to solve the above-mentioned problems, a water intake control device for a water purification plant according to the present invention comprises a means for measuring the amount of water distribution in a reservoir and a measurement result for a plurality of days of the amount of water distribution. Means for averaging to determine the latest time change in water distribution;
A means for determining the target water level of the reservoir based on the latest time change of the water distribution volume, and a planned water intake such that the water intake is changed only when the target water level reaches an extreme value so that the reservoir is maintained at the target water level Means for determining the amount.

Therefore, the measurement result of the water distribution amount for several days is averaged to determine the time change of the water distribution amount based on the latest water demand. In this case, the seasonal fluctuation of the water demand is immediately reflected in the time change. Is done.

Then, based on the latest time change of the water distribution, a target water level in accordance with the latest water demand is determined. The time between the extremes of the target water level is defined as a uniform water flow time zone. The planned water intake is determined so that only the water intake is changed and the water level in the reservoir is maintained at the target water level.

In this case, the target water level of the reservoir and the time zone of uniform water intake are determined in real time in accordance with the latest changes such as seasonal fluctuations in water demand, so the plan determined based on these information. With the intake of water intake, the difference between the predicted and actual water level of the distribution reservoir is less likely to occur, and the number of changes in the water intake during operation is significantly reduced.

As a result, the water quality is stabilized, the burden caused by the fluctuation of the water intake of the equipment for the purification treatment is reduced, and the life of the equipment is prolonged.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In the water purification plant of FIG. 1, the same reference numerals as those in FIG. 4 denote the same components, and the intake control device 9 that replaces the intake control device 5 in FIG.

A flow meter (not shown) for measuring the amount of water distribution in the reservoir 3 is used near the distribution port of the reservoir 3, and the flow meter is used, for example, from 0:00 to 1:00, from 1:00 to 2:00. ,... Are supplied to the target water level / time zone determination block 10 of the water intake control device 9.

This decision block 10 is implemented by software processing of a microcomputer.
(Ii) and (iii) are provided. (I) Means for calculating the latest time change of the water distribution amount by averaging the measurement results for a plurality of days of the water distribution amount. (Ii) Determining the target water level of the reservoir 3 based on the latest time change of the water distribution amount. Means (iii) Means for determining each time between extreme values of the target water level as a time zone for uniform water flow

Next, the specific processing of the decision block 10 will be described. First, information on the measured flow rate D is collected and accumulated, and as shown in FIG. 2, for example, a measurement result for a plurality of days, such as the latest about 10 days, is obtained as water distribution amount actual data for a certain period of time.

If the number of collection days is too large, the detection of fluctuation due to seasonal change or the like occurs, so
About 0 days is appropriate.

In order to improve the detection accuracy, for example, weekdays and holidays may be distinguished, and the measurement results for weekdays and the holidays may be obtained separately.

Next, for example, an average process of a simple average is performed on the water distribution amount actual data for about 10 days, and as shown in FIG. Is calculated as a temporal change of the representative water distribution.

Further, based on the data of the time variation of the representative water distribution, the water level fluctuation of the reservoir 3 when the water intake is operated under the condition of the water distribution is determined. The target water level h _O ^* according to the water demand of the reservoir 3 shown in FIG. The target water level h _O ^* is always lower than the upper water level h _{H and} higher than the lower water level h _L.

As shown in FIG. 2D, the time from the maximum value or the minimum value of the target water level h _O ^* to the next minimum value or the maximum value of the target water level h _O ^* is defined as a constant water intake time zone. Determined as Tw ^* .

The constant water intake time Tw ^* is the time between the extremes of the target water level h _O ^* in order to minimize the change of the water intake, and the changing tendency of the reservoir 3 Depending on, for example, the time zone between the maximum values or the minimum value may be set.

Then, the information of the determined target water level h _O ^* and the water intake uniform time zone Tw ^{* is used} as the conventional target water level h _O , FIG.
The water supply amount is supplied to the water intake amount determination block 11 instead of the information of the water intake uniform time zone Tw.

This determination block 11 is provided instead of the water intake amount determination block 7 in FIG.
It has the means of v) and operates in the same way as the decision block 7.
(Iv) a target level h _O ^* means for determining a design intake flow B ^* as by changing the amount of water intake distributing reservoirs 3 is maintained at the target water level h _O ^* when become extreme

Next, a specific process of the water intake amount determination block 11 will be described. First, this decision block 11
As in the conventional decision block 7 of FIG. 4, the water demand prediction block 6 is provided with information on the predicted water demand A on the next day shown in FIG.

The information on the upper limit water level h _H and the lower limit water level h _L of the reservoir 3 shown in FIG. 3B is set in advance by an operator operation or the like as in the decision block 7. b)
The information of the target water level h _O ^* and the water intake uniform time zone Tw ^* is given from the target water level / time zone determination block 10 based on the actual measurement result of the water distribution amount.

Based on these information, the decision block 11 decides, for example, the daily planned water intake B ^* shown in FIG. 3C in the same manner as the conventional decision block 7.
When the planned water intake B ^* reaches an extreme value, that is, at the beginning (end) of each water intake uniform time zone Tw ^* , the water intake is changed as necessary to control the water intake.

Based on the planned water intake B ^* , the predicted reservoir water level h _y ^* and the target upper water level h _yH ^* shown in FIG. _3D are similar to the water levels h _y , h _yH , and h _yL in FIG. , Target lower water level h
determined to seek a _yL ^*, these water level _{^{h y *, h yH *,}} h yL *
Is supplied to the water level monitoring block 8.

If a water level abnormality occurs in the distribution reservoir 3 during the water intake control during operation based on the planned water intake B ^* , the water level monitoring block 8 issues a water intake review command C to the water intake determination block 11, and the command C is issued. Correct the planned water intake B ^* .

In this case, the target water level h _O ^* and the water intake uniform time zone Tw ^{*, which} are the basis of the determination of the planned water intake B ^* , are the latest water distribution, that is, the time variation including the seasonal fluctuation of water demand. Is determined in consideration of the time change of the water demand, the planned water intake B ^* is appropriately changed and determined in accordance with the latest water demand.

Accordingly, the difference (deviation) between the predicted water level h _O ^* of the reservoir 3 and the actual water level (actual water level) hardly occurs due to the water intake control based on the planned water intake B ^* , and the two almost coincide. In addition, the number of review commands C during operation becomes extremely smaller than before, and the number of days for changing the amount of water withdrawal is drastically reduced.

As a result, the fluctuation of the water intake amount is reduced, the treatment in the water purification treatment equipment 2 is performed stably, the water quality of the purified water is stabilized, and the load on the machinery in each step of the equipment 2 is reduced. The extension of the service life is achieved.

[0050]

The present invention has the following effects. The uniform time zone between the extremes of the target water level and the target water level where the water intake is kept constant is the average time change of the real-time results of the water distribution of the reservoir 3 over the last few days. Based on this, the water level is automatically determined in real time at an appropriate water level and time zone in accordance with a change in the amount of water distribution due to seasonal fluctuations in water demand.

Therefore, the planned water intake determined on the basis of this information is in accordance with the time change of the latest water demand, and the water intake control at this planned water intake causes the difference between the water level of the distribution reservoir 3 and the predicted water level. The number of days for changing the amount of water intake during operation based on this deviation is significantly reduced, the amount of water intake is stabilized, the water purification process is stabilized, and the quality of the purified water is stabilized. It is possible to reduce the burden caused by fluctuations in the water intake of the processing equipment, and to extend the life of the equipment.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIGS. 2A to 2D are explanatory diagrams of a process for determining a target water level h _O ^* and a uniform water intake time zone T _W ^* of FIG. 1;

3 (a) to 3 (d) are explanatory diagrams of a process for determining a planned water intake B ^* and a predicted water level h _y ^* in FIG.

FIG. 4 is a block diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake channel 2 Water purification equipment 3 Reservoir 4 Distribution channel 5, 9 Intake control device 6 Water demand prediction block 7, 11 Intake volume determination block 8 Reservoir water level monitoring block 10 Target water level / time zone determination block

Claims (1)

[Claims] 1. A water intake amount for each day is controlled in accordance with a time-varying planned water intake amount determined based on a prediction of water demand. When the water level is about to deviate from the target water level, the water intake control device of the water purification plant in which the planned water intake is corrected and the control of the water intake is repeated, and the water level of the reservoir is maintained at the target water level. Means for measuring the amount of water distribution in the reservoir, means for averaging measurement results for a plurality of days of the amount of water distribution to obtain the latest time change in the amount of water distribution, and Means for determining the target water level based on the target water level, and means for changing the water intake amount only when the target water level reaches an extreme value and determining the planned water intake amount so that the reservoir is maintained at the target water level. It is characterized by having The water intake control device of the water purification plant.