JPS63101905A - Operation monitor and control equipment for filter plant - Google Patents

Abstract

PURPOSE:To suppress load variation at a remarkably low level by operating and controlling an object to be operated based on an operation plan, a simulated result and a detected value. CONSTITUTION:When the flow rate of water distribution in a filter plant is forecast, an operation plan forming means 102 forms an operation plan of an object 106 to be controlled based on the forecast value for the flow rate of water distribution so that a change in the flow rate of water variation can be suppressed at its minimum by using the capacity of a water distribution pond. On the other hand, a simulation means 103 finds out the transition of either one of process values such as a water level in the water distribution pond or a flow rate relating to the water level in case of operating the object 106 based on the operation plan formed by the means 102 on the supposition that the forecast value is the flow rate of water distribution. A process detecting means 104 detects a practical process value. Thereby, a monitor and control means 105 operates the operation object 106 in accordance with the operation plan and controls the correction of the operation object 106 so that a deviation between the simulated result and the process detection value is reduced to less than a prescribed value.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention utilizes the capacity of a water distribution reservoir or a water purification reservoir (hereinafter simply referred to as a water distribution reservoir) to reduce load fluctuations in lands suitable for settling and filtering. and fluctuations in the amount of water intake or landing (hereinafter included in load fluctuations)
This invention relates to an operation monitoring and control device for a water treatment plant that keeps water to a minimum.

(Prior Art) FIG. 4 is a block diagram showing a schematic configuration of this type of conventional operation monitoring and control device. When the demand forecasting means 101 predicts the water distribution flow rate of a water treatment plant using weather data and water distribution results, The operation plan creation means 102 determines the water intake amount and filtration flow rate at each time, and determines the water intake amount and filtration flow rate at each time, based on the water distribution flow rate prediction value of the demand forecasting means 101, so as to minimize fluctuations in water landing amount by utilizing the capacity of the water distribution reservoir. and create an operation plan such as the pump operation sequence. In addition, the monitoring control means 105 controls various valves and pumps according to the operation plan of the operation plan creation means 102, and also monitors the water level of the water distribution reservoir based on the output signal of the water level meter 16 that detects the water level of the water distribution reservoir 3. For example, the flow control valve 6 is corrected and controlled each time the upper or lower limit of the range is exceeded.

(Problems to be Solved by the Invention) In the conventional water treatment plant operation monitoring and control device described above,
When the accuracy of water distribution flow rate prediction by the demand prediction means 101 is high,
In addition, when the capacity of the water distribution reservoir is large, load fluctuations can be suppressed extremely effectively.

However, if sufficient accuracy cannot be expected in predicting the distribution flow rate, or if the capacity to accommodate the permissible fluctuation range of the water level in the distribution reservoir is small, there is a risk that load fluctuations will increase.

FIG. 5 is a diagram showing the relationship between time and water level to explain this, and the upper limit of the permissible variation range of water level in the water distribution reservoir at the time of creating the operation plan is hl.

If the water level of the water distribution reservoir changes gradually within the permissible fluctuation range as shown by curve X with the lower limit being h2, the supervisory control means 105 will not perform correction control.

However, if the water level in the water distribution reservoir fluctuates as shown by curve Y due to an error in predicting the water distribution flow rate, and exceeds the upper limit h1 at time t, the monitoring control means 105 performs correction control at this time. Performing such correction control will only increase load fluctuations, and if the occurrence of disturbance is detected late, significant correction will be required.

Thus, conventional water purification plant operation monitoring and control devices have the problem of performing control that is contrary to the initial purpose of suppressing load fluctuations.

The present invention has been made to solve the above problems, and is an operation monitoring and control device for a water purification plant that can significantly reduce load fluctuations without being affected by the accuracy of water distribution flow rate prediction or the capacity of a water distribution reservoir. The purpose is to provide.

[Structure of the invention]

(Means for Solving the Problems) As shown in FIG.
An operation plan creation means 102 that creates an operation plan for operating targets such as valves and pumps based on the predicted water distribution flow rate of the demand forecasting means 101 and an operation plan of the operation plan generation means. a simulation means 103 for determining a temporal change in a process value of either a water level or a flow rate related to this water level; a process detection means 104 for detecting a process value simulated by this simulation means 103; and an operation plan. Monitoring control means 1 that operates and controls the operation target 106 based on the operation plan of the creation means 102, the simulation result of the simulation means 103, and the detected value of the professional detection means 104.
05.

(Function) In the present invention, when the demand forecasting means 101 predicts the water distribution flow rate of the water treatment plant using weather data and water distribution results,
Based on this predicted water flow rate, the operation plan creation means 102 uses the capacity of the distribution reservoir to create an operation plan for the operation target 106 so as to minimize fluctuations in the landing flow rate, while the simulation means 103 Assuming that the predicted value is the water distribution flow rate, the transition of any one process value such as the water level of the water distribution reservoir or the flow rate related to this water level is determined when the operation target is operated according to the operation plan of the operation plan generation means 102. Further, a process detection means 104 detects an actual process value. Therefore, the supervisory control means 105 operates the operation target 106 according to the operation plan of the operation plan generation means 102, and operates the object 106 so that the deviation between the simulation result of the simulation means 103 and the detected value of the process detection means 104 is equal to or less than a predetermined value. Correction control is performed on the target 106.

As a result, even if an error occurs between the predicted value and the actual value of water distribution flow, or if the water treatment plant's capacity is quite small and the water level tends to fluctuate greatly, the difference between the operation plan and the actual operation result can be confirmed. Since it is detected early and corrected, load fluctuations can be kept extremely small.

(Embodiment) FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. In the same figure, after the landing well 1, there is a suitable area for settling and filtration 2.
and a water distribution reservoir 3 are arranged in this order, and among these, a flow control valve 4 for adjusting the landing flow rate is installed in front of the landing well 1 in order to suppress the load fluctuation of the settling/filtering suitable site 2 and the fluctuation of the landing water amount. In addition to being provided with a flow meter 5 that measures the flow rate of landing water, meteorological data 11 and water distribution amount! a demand forecasting device 13 that predicts the water distribution flow rate using g112, an operation plan creation device 14 that creates an operation plan for the flow i control valve 4 from the water distribution amount predicted value of the demand forecasting device 13, and a demand forecasting device 13.
A simulation device 15 that calculates temporal changes in the water level of the water distribution reservoir 3 based on the water distribution amount prediction and operation plan of the operation plan creation device 14, and a water level that detects the water level of the water distribution reservoir 3:
The water level signal of f16 and the simulation result of the simulation device 15 are compared, and when the difference is less than ±DH, the landing flow rate set value according to the operation plan of the operation plan creation device 14 is outputted, and the difference is ±DH. A monitoring device 17 that outputs a water landing flow rate set value with corrections made to the above operation plan when the flow rate exceeds the above.
and a feedback control device 18 that operates the flow rate control valve 4 so that the deviation between the water landing flow rate set value of the monitoring device 17 and the flow rate signal of the flow meter 5 becomes zero.

The operation of this embodiment configured as described above will be explained below.

First, the demand forecasting device 13 uses weather data 11 and water distribution record 1.
When the water distribution flow rate is predicted based on 2, the operation planning device 1
4 creates an operation plan that utilizes the capacity of the water distribution reservoir 3 and minimizes the landing flow rate. The simulation device 15 assumes that water is sent according to the water distribution flow rate prediction value of the demand prediction device 13, and calculates the temporal change in the water level of the water distribution reservoir 3 by the method described below.

In other words, the water level of the distribution reservoir 3 at time t is h 1 The water level of the suitable sinking/filtering site 2 is h 1 The water level of the water well 1 p
Let the water level of r be h, the inflow flow rate of landing well 1 be q, and the sedimentation
Let the inflow flow rate of the well 2 be
The filtration flow rate of the suitable settling area 2 is q (t), and the water head loss between the suitable settling area 2 and the distribution reservoir 3 is r2 (q,).
, the amount of water supplied is q. shall be.

In addition, the landing well area is A1, and the area suitable for sedimentation and filtration is A1.
Letting the area of the water distribution reservoir be A, the following formula p holds true at each time.

ha-hr-rl (qr)・・・・・・・・・・・・
...(4) h , h , -r 2 (q p
)...................................................(5) Then, the simulation means 15 performs h.

For example, the Newton-Raphson tangent method or the Runge-Kutta forward integral formula can be used with h , h , q , q , and q as the initial values, the water supply amount parp q as the demand forecast value, and the landing water flow 1 k q t as the operation plan value. The change in water level h in the water distribution reservoir over time is calculated using the following formula.

Next, the monitoring device 17 calculates a landing flow rate setting value according to the operation plan of the operation plan generation device 14 and outputs it to the feedback control device 18. Furthermore, the monitoring device 17 includes a water level gauge 1
Compare the water level of the distribution reservoir detected by 6 with the simulated water level of the simulation device 15, and when the difference exceeds DH within the allowable error range, calculate the landing flow rate set value with correction to the operation plan and feed it back. Control device 1
Output to 8.

Therefore, the feedback control device 18 controls the flow control valve 4 so that the flow rate detected by the flowmeter 5 and the flow rate set value of the monitoring device 17 are equal.

FIG. 3 shows the time t to explain the control operation of this embodiment.
This is a diagram showing the relationship between the distribution reservoir water level h and the upper limit of the distribution reservoir water level as h and the lower limit as h2, and it is assumed that the simulated water level of the simulation device 15 changes gradually as shown by the curve P. do. The monitoring device 17 monitors whether the actual water level of the water distribution reservoir 3 is within the permissible error range ±DI (with respect to the simulated water level shown by the curve P), that is, whether it exceeds the curves U and L. If the distribution reservoir water level changes as shown by curve Q due to the influence of disturbance and exceeds curve U at time t, the operation plan is corrected at this point, and the flow rate is set in accordance with the corrected operation plan.

In this way, in the conventional system, correction control is performed when the water level in the water distribution reservoir exceeds the preset upper limit h1 and lower limit h2, so load fluctuations may become significantly large, but in this embodiment, the actual water level relative to the simulated water level is Since correction control is carried out at the stage when DH exceeds the error range DH, load fluctuations can be suppressed.

In the above embodiment, the simulation device 15 simulates the water level in the distribution reservoir, and the monitoring device 17 compares the simulated water level with the water level detected by the water level gauge 16. Instead, the simulation device 15 simulates the water level in the distribution reservoir. Even if the monitoring device 17 is configured to compare the simulation result with the flow rate detection value while simulating the flow rate related to the water level of the flow rate, substantially the same control as described above can be performed. .

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, even when the water treatment plant operation plan is no longer satisfied due to disturbance,
This can be detected at an early stage, which has the effect of significantly suppressing sedimentation, filtration tank load fluctuations, etc.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of the present invention, Figure 2 is a block diagram showing the configuration of an embodiment of the present invention together with a water purification system, and Figure 3 is for explaining the operation of the embodiment. A line diagram showing the relationship between the water level in the water distribution reservoir and time. Figure 4 is a block diagram showing the configuration of a conventional operation monitoring and control device for a water purification plant. Figure 5 shows the water level in the water distribution reservoir to explain the operation of the device. It is a diagram showing the relationship between and time. 1... Water landing well, 2... Sedimentation/filtration basin, 3... Distribution reservoir, 4... Flow rate control valve, 5... Flow meter, 13...
・Music requirement prediction device, 14... Operation plan creation device, 15.
...Simulation device, 16...Water level gauge, 17.
... Monitoring device, 18... Feedback control device. Applicant's agent Mr. Sato Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] A demand forecasting means that predicts the water distribution flow rate of a water treatment plant using weather data and water distribution records, and based on the water distribution flow rate predicted value of this demand forecasting means, minimizing fluctuations in the water arrival flow rate by using the capacity of the water distribution reservoir. an operation plan creating means for creating an operation plan for operation targets such as valves and pumps; simulation means for determining the time course of a process value of either the water level of the water distribution reservoir or the flow rate related to this water level when the system is operated; and process detection for detecting the process value simulated by the simulation means. and operating the operation target according to the operation plan of the operation plan creation means, and correcting the operation target so that the deviation between the simulation result of the simulation means and the detected value of the process detection means is equal to or less than a predetermined value. 1. An operation monitoring and control device for a water purification plant, comprising a monitoring and control means for controlling the water purification plant.