JPH09242674A - Pump operation controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the water level in a pump well, and improve the operational controllability of a sanitary sewage pump even when an actual raw water flow deviates from the predicted value of a raw water flow. SOLUTION: The delivery proposed value Qp of a pump 44 and the water level proposed value Lp of a pump well 43 are found out in a delivery proposition calculating part 22 on the basis of a raw water inflow predicted value predicted in an inflow prediction calculating part 21. A delivery correction value is found out in a delivery correcting part 11 from the operation states of a pump on the basis of a water level measured value L from a water gage 47 and the water level proposed value Lp, and the delivery proposed value Qp is corrected by this delivery correction value so as to find out a delivery target value Qr. The operation of a sanitary sewage pump 44 is controlled on the basis of the delivery target value Qr in a delivery control part 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device provided in a sewage pump for smoothing sewage flowing into a sewage treatment plant from a sewage pipe and sending it to a treatment facility. The present invention relates to a pump operation control device capable of performing stable discharge amount control based on the above.

[0002]

2. Description of the Related Art A sewage treatment plant sewage pump is used to send sewage flowing into a sewage treatment plant to a treatment facility. Needs to be properly controlled. The sewage pump also has the purpose of promptly sending the sewage flowing into the sewage treatment plant to the treatment facility and appropriately discharging the sewage in the sewage pipe.

Next, a conventional operation control device for such a sewage pump will be described. FIG. 6 is a process flow diagram showing the process of the sewage pump equipment. In FIG. 6, the sewage flowing in from the sewage pipe 41 flows into the pump well 43 via the sand basin equipment 42 of the sewage treatment plant. A sewage pump 44 is installed in this pump well 43, and the pump well 4
Sewage flowing into 3 is sequentially transferred to the discharge tank 50 and the treatment facility 51 of the sewage treatment plant.

In such a sewage pump, a conventional operation control device for the sewage pump will be described. FIG. 7 and FIG. 8 are diagrams showing an example of the operation control device for the sewage pump.

In FIG. 7, the sewage pump 44 is a flow meter 4
In order to make the discharge amount measured value measured in step 5 the target value, the discharge amount control unit 46 controls the number of operating vehicles (ON / OFF) using the operating unit number control unit 24 and the rotational speed control (MV). Has been done. In addition, the discharge amount target value given to the discharge amount control unit 46 is the water level gauge 4 installed in the pump well 43.
It is set by the water level flow rate calculation unit 47a based on the water level measurement value from 7.

In the sewage pump operation control device having such a configuration, in order to stabilize the discharge amount with respect to the fluctuation of the inflow amount, the function calculator of the water level-flow rate function shown in FIG. To calculate the target value of the discharge amount. As a result, even if the inflow amount of sewage changes, the actual discharge amount can be kept constant and the discharge amount can be stabilized as long as the water level in the pump well 43 changes in the section from a to b. it can.

That is, the sewage pipe 41 is used as a buffer for the inflow of sewage, and the fluctuation of the inflow of sewage is controlled by the pump well 4
It is absorbed as the fluctuation of the water level of No. 3 and the discharge amount pumped to the treatment facility 51 is smoothed. Such a method is an effective method when the fluctuation of the inflow amount of sewage per day is within a certain range, but the controllability is not good for the change that deviates from this range.

Therefore, conventionally, as shown in FIG. 9, the inflow predicting unit 21 predicts the inflow of sewage, and the flow rate of inflow of the sewage every hour of the day is calculated based on past statistics and the measured water level in the sewer pipe. It is calculated from the prediction of the runoff. This inflow amount predicted value is input to the discharge amount plan calculation unit 22, and the discharge amount planning calculation unit 22 uses the pump well 43 based on this inflow amount predicted value.
The estimated discharge level target value Qr is calculated by using the operating water level of the pump well 43 as a buffer for the inflow amount of sewage in the maximum width. This discharge amount target value is input to the discharge amount control unit 46 every hour, and the discharge amount control unit 46 performs feedback control or the like so that the discharge amount measurement value Q becomes the discharge amount target value Qr.

[0009]

However, in the pump control device as shown in FIG. 9, since the operating water level of the pump well 43 is used as the maximum width buffer to control the discharge amount, the inflow prediction is actually performed. , The water level of the pump well 43 may drop to reach the pump stop water level, or the water level may rise to an abnormally high water level in the pump well.

Further, in order to correct such a deviation from the prediction, if frequent replanning is performed to correct the predicted inflow amount and the target value Qr of the discharge amount, it is necessary to stabilize the replanning and correction. The target discharge amount Qr is changed every time it is corrected, and the actual discharge amount Q may fluctuate or the fluctuation may be amplified.

It is also conceivable to set the interval for re-planning or correction to one hour or the like to suppress the fluctuation, but in this case, it is not possible to follow a rapid decrease or increase in the inflow of wastewater.

The present invention has been made in consideration of the above points, and a pump operation capable of performing stable discharge amount control even when the actual inflow amount of wastewater deviates from the predicted inflow amount in a short period of time. An object is to provide a control device.

[0013]

The present invention provides a pump based on an inflow prediction calculation unit for predicting an inflow amount of raw water into a pump well in which a pump is installed, and a raw water inflow prediction value from the inflow prediction calculation unit. Discharge plan calculation value and pump water level plan value of the discharge well, a water level meter that measures the water level of the pump well, a pump well water level plan value from the discharge quantity calculation unit, and a pump well from the water level gauge A discharge amount correction unit that calculates a discharge amount correction value from the operating condition of the pump well based on the measured water level, and calculates a discharge amount target value by correcting the discharge amount planned value based on this discharge amount correction value, and a discharge amount correction unit A pump operation control device, comprising: a discharge amount control unit that controls the operation of the pump based on the discharge amount target value obtained in.

According to the present invention, the discharge amount plan calculation unit and the pump well water level plan value are obtained in the discharge amount plan calculation unit based on the raw water inflow prediction value predicted by the inflow prediction calculation unit. Next, in the discharge amount correction unit, the discharge amount correction value is obtained from the operating condition of the pump based on the pump well water level planned value from the discharge amount plan calculation unit and the pump well water level measured value from the water level gauge. The discharge amount plan value is corrected by the correction value to obtain the discharge amount target value. The discharge amount control unit controls the operation of the pump based on the discharge amount target value.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of a pump operation control device according to the present invention.

First, the entire sewage treatment plant will be described with reference to FIG. As shown in FIG. 1, the sewage treatment plant includes a sand basin facility 42 into which sewage from the sewage pipe 41 flows, and a pump well 43 connected to the sand basin facility 42.

Of these, the pump well 43 has a sewage pump 44.
Is installed, and the wastewater sent by the wastewater pump 44 is sequentially sent to the discharge tank 50 and the treatment facility 51. A flow meter 45 is installed between the discharge tank 50 and the processing facility 51.

Next, an operation control device for controlling the operation of the sewage pump 44 will be described. As shown in FIG. 1, the pump operation control device predicts the inflow amount of sewage into the pump well 43, and the discharge amount plan described below based on the raw water inflow amount prediction value from the inflow prediction calculation unit 21. A discharge amount plan calculation unit 22 for determining the discharge amount planned value Qp of the sewage pump 44 and the pump well water level planned value Lp in consideration of the pump water level measured value from the correction unit 23.

A water level gauge 47 for measuring the water level in the pump well 43 is installed in the pump well 43, and the water level gauge 47 is connected to the discharge rate correction unit 11 and the discharge rate plan correction unit 23.
The discharge amount correction unit 11 obtains a discharge amount correction value from the operating condition of the pump well 43 based on the pump water level planned value Lp from the discharge amount plan calculation unit 22 and the pump well water level measured value from the water level gauge 47, and this discharge The discharge amount target value Qr is obtained by correcting the discharge amount planned value Qp with the amount correction value. In addition, the discharge amount plan correction unit 23 uses the discharge amount plan calculation unit 2
When the discharge amount plan calculation unit 22 is connected to No. 2, the pump well water level measurement value is taken into consideration for the calculation.

Further, the discharge amount correction unit 11 is connected to a discharge amount control unit 46 which controls the operation of the sewage pump 44 based on the discharge amount target value Qr. That is, the discharge rate control unit 46 controls the number of operating sewage pumps 44 by the operating unit number control unit 24 (ON / OFF) and also controls the number of revolutions (MV).

Next, the operation of this embodiment having such a configuration will be described. First, the sewage flowing into the sand basin equipment 42 from the sewage pipe 41 reaches the pump well 43 after removing large dust in the sand basin equipment. Pump well 43
The sewage therein is sequentially sent to the discharge tank 50 and the treatment facility 51 by the sewage pump 44.

Next, operation control of the sewage pump 44 will be described. First, the inflow prediction calculation unit 21 predicts the inflow amount of sewage into the pump well 43, and this estimated inflow amount value is input to the discharge amount plan calculation unit 22. In the discharge amount plan calculation unit 22, the discharge amount planned value Qp and the pump water level planned value Lp of the sewage pump are obtained in consideration of the pump water level measurement value L measured by the water level meter 47 and sent from the discharge amount plan correction unit 23. To be

Next, the discharge amount plan value Qp and the pump well water level plan value Lp obtained by the discharge amount plan correction unit 23 are input to the discharge amount correction unit 11. The operation in the ejection amount correction unit 11 will be described in detail below.

As shown in FIG. 1, the ejection amount correction unit 11 includes
Discharge amount planned value Qp, water level measured value L, and water level planned value Lp
Is input. In the discharge amount correction unit 11, the deviation of the water level measurement value L from the planned water level value Lp is calculated as shown in FIG. 2, and the water level measurement value L is input to the fuzzy inference calculation unit 14 for the correction amount calculation together with the deviation. To be done. The deviation of the water level and the water level measurement value L are input to the fuzzy inference calculation unit 14, which is quantified as a fuzzy set by each of the membership functions 12 and 12, and an inference unit that performs fuzzy inference via the antecedent unit 13 14a. Inference unit 14
In a, inference is performed with reference to the knowledge rule for determining the degree of correction amount from the degree of deviation between the measured water level value and the planned water level value, and is output as the ejection amount correction value via the consequent unit 15. . The discharge amount correction value is output to the correction addition / subtraction unit 16 together with the discharge amount planned value Qp. Correction addition / subtraction unit 16
Then, add the discharge amount plan value Qp and this discharge amount correction value,
It is output as the discharge amount target value Qr.

FIG. 3 is a diagram showing an example of a membership function for quantifying an input value as a fuzzy set. This input membership function has an empirical value as the degree of input, and PB: water level or deviation is positive and very large. PS: Water level or deviation is positive and somewhat large. ZO: No water level or deviation. NS: Water level or deviation is negative and somewhat large. NB: The water level or deviation is negative and very large. Of 5 stages, and inputs to the inference unit 14a.

FIG. 4 is a diagram showing an example of determination rules in fuzzy inference. In this judgment rule shown in FIG. 4,
For example, when the water level measured value is PB and the water level planned value deviation is PB, the correction value is NB, and the determination rule describes the degree of output in a matrix.

FIG. 5 is an example of a membership function for converting the fuzzy set resulting from the fuzzy inference to obtain the output value of the ejection amount correction value.

In this output membership function, the degree of output as a result of fuzzy inference is quantified and output as a correction value.

Since the output membership function obtains the output value from the fuzzy set resulting from the fuzzy inference, PB: the correction amount is positive and very large. PS: The correction amount is positive and slightly large. ZO: No correction. NS: The correction amount is negative and somewhat large. NB: The correction amount is negative and very large. The ejection amount correction value is calculated by the gravity center conversion method or the like in which the respective degrees are superposed from the five stages.

Next, a specific inference will be described with reference to FIG. If the inference rule is set as shown in Fig. 4,
If the deviation between the planned water level and the measured water level is ZO, the output range will be Z regardless of the level of the measured water level.
Since it becomes O, the correction output becomes no correction, and the correction output becomes 0 from the output membership function. In other words, if the measured water level is the water level predicted by the planned water level, no correction is considered necessary.

When the measured water level is near the upper limit (PB, PS), the deviation from the planned water level is positive (PS, PS,
In the case of PB), that is, when the measured water level is larger than the planned water level, the current water level is higher than the predicted water level, so it can be seen that the prediction is off. In this case, the water level may reach the upper limit of the water level. Therefore, the discharge amount target value is increased from the discharge amount planned value to stabilize the water level as a setting for correcting the positive (PS, PB) according to the degree. Correct in the direction.

On the contrary, when the measured water level is near the upper limit (PB, PS), the deviation from the planned water level is negative (N
(S, NB), that is, when the measured water level is smaller than the planned water level, the prediction is off, but the current water level is lower than the predicted water level, so no correction is made (ZO). Alternatively, a slight negative correction (NB) is applied to lower the discharge amount target value from the discharge amount planned value and the water level is returned to the planned value.

Even when the water level measurement value is near the lower limit, the inference rule is set in the same manner as described above, and according to the input water level measurement value and the degree of the water level plan value deviation,
The correction value is determined according to the setting of the inference rule matrix.

According to the present embodiment, even when the actual inflow amount deviates from the inflow predicted value, the planned discharge amount is adjusted depending on the difference between the measured water level in the pump well 43 and the planned water level. Therefore, the operating water level of the pump well 43 can be stably maintained even if the predicted inflow amount deviates.

When a deviation between the actual inflow amount and the inflow amount predicted value occurs, if the deviation from the actual inflow amount predicted value is empirically known, the fuzzy inference rule matrix is set. Can be changed easily. Therefore, by setting rules according to experience, fluctuations in the discharge amount of the sewage pump 44, that is, the pumped-up amount to the treatment facility 51 are prevented as much as possible while protecting the operating water level of the pump well even if the inflow fluctuations occur in a short period of time. be able to.

[0036]

As described above, according to the present invention,
The discharge amount correction unit corrects the discharge amount planned value based on the water level planned value and the water level measured value to obtain the discharge amount target value, so even if the raw water inflow predicted value and the actual inflow amount are different,
It is possible to stabilize the water level change of the pump well caused by the deviation. Therefore, it is possible to prevent the water level of the pump well from deviating from the operating water level, and to prevent a large change in the discharge amount due to the dangerous water level of the pump well or the stop water level due to the deviation from the operating water level.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a pump operation control device according to the present invention.

FIG. 2 is a diagram showing a configuration of a discharge amount correction unit according to the present invention.

FIG. 3 is a diagram showing an input membership function of fuzzy inference.

FIG. 4 is a diagram showing a decision rule for fuzzy inference.

FIG. 5 is a diagram showing an output membership function of fuzzy inference.

FIG. 6 is a flowchart illustrating a process of a general sewage pump facility.

FIG. 7 is a diagram showing a configuration of a conventional pump operation control device.

FIG. 8 is a diagram showing an example of a conventional water level-flow rate function.

FIG. 9 is a diagram showing a configuration of a conventional pump operation control device having an inflow prediction control function.

[Explanation of symbols]

 11 Discharge amount correction unit 21 Inflow prediction calculation unit 22 Discharge amount plan calculation unit 43 Pump well 44 Sewage pump 46 Discharge amount control unit

Claims (1)

[Claims] 1. A discharge amount plan value and a pump water level of a pump based on a raw water inflow calculation unit that predicts a raw water inflow amount into a pump well in which a pump is installed, and a raw water inflow amount prediction value from the inflow prediction calculation unit. Based on the discharge plan calculation unit to obtain the plan value, the water level gauge to measure the water level of the pump well, the pump well water level plan value from the discharge plan calculation unit, and the pump well water level measurement value from the water level gauge. The discharge amount correction value is obtained from the operating conditions of the discharge amount, and the discharge amount target value is obtained by correcting the discharge amount plan value with this discharge amount correction value. A pump operation control device comprising: a discharge amount control unit for controlling the operation of the pump based on the above.