JPS58189712A - Method for controlling pumping-up volume of sewage pump - Google Patents

Abstract

PURPOSE:To reduce the variation of the volume of flow-in sewage, by estimating the volume of the flow-in sewage from the measured values of a pump sand sedimentation basin, a pump well and a flow-in sewer, etc., and the measured value of the pump flow rate and then deciding the pumping reference value to obtain the correction degree of pump operation. CONSTITUTION:A water gauge 2 is set for a pump sand sedimentation basin 1, a pump well and a flow-in sewer at a sewage pump center. The gauge 2 measures the overall water level of the basin 1, and a flowmeter 4 measures the pumping volume of a pump 3. A sewage flow-in volume estimating means 5 estimates the flow-in volume of sewage by means of the gauge 2 and a meter 4 and then by a flow-in volume presuming means 8. Then a programming means 9 decides the reference pumping volume by means of a time series of the estimated value of the means 8. A water level feedback means 7 compares the reference water level of the next step obtained by the means 9 with the water level indicated by the gauge 2 and then gives a feedback correction to the operation of the pump 3 to correct the reference pumping volume. In such a way, an estimation error of the flow-in sewage volume is reduced to assure the proper control of the sewage pumping volume.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the amount of water pumped by a sewage pump, and more specifically, a method for controlling a sewage pump pumping lid, which predicts the amount of inflow sewage at a sewage pump station and controls the amount of water pumped by the pump. It is related to.

A conventional pump lift lid control method is shown in FIG. In the figure, a water level 'rn2 for measuring the water level of this sediment al is placed in a settling basin l of a sewage pump station.

This water level gauge 2 is the settling pond population.

Multiple units are installed in sand settling ponds, pump wells, inflow prefectures, etc., and there are slight differences depending on their structure.

Since it shows the sediment a/total water level as a whole, it is expressed here as seven water level gauges.

Further, it is possible to configure a similar control method no matter which water level gauge is used. In addition, there is a pump 3 that has a pumping function to pump up the inflowing sewage, and an Ft that measures the amount of pumped water.
6. A 10-step inflow estimating step S for estimating the amount of inflowing sewage from the measured value of the water level gage and the amount of pumped water, and a conversion means for determining the water level standard from this estimated inflow lid.6. A device was used in which a water level feedback means 7 for determining a pumped water amount correction value from a water level instruction 1 from the process and a water level reference value determined by a converting means 6 was connected.

With the above configuration, the inflow sewage cover is estimated by the inflow estimating means S from the flow meter and the water level gage. Drifter estimation means S
An outline of the estimation method is shown in the following form.

(Amount of inflow sewage) = (Amount of pumped water) + (Water area) x (Width of change in water level per unit time) (1) The parameter “Water area” used here is a constant determined by the civil engineering structure of the treatment plant. . Next, a water level standard value is determined by a conversion means B having a characteristic curve, corresponding to this inflow sewage estimated value. Next K.

The water level feedback means 7 corrects the amount of pumped water based on this water level reference value and the process water level instruction value. This modification of the amount of water pumped is performed, for example, in the following manner.

(Pumping amount correction value) = (Gain) × ((Water level indication value) - (Water level standard (II)) (K)
Usually, this water level feedback means 7 is as follows.

The first clause of aM1 is more often used than P.

The conventional control method is as described above, so even if the inflow sewage cover changes, large fluctuations in the amount of inflow sewage can be absorbed by simply changing the water level reference value along a predetermined pattern. I couldn't do it.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by predicting the inflow sewage cover using the estimated time of the inflow sewage cover, the inflow sewage The object of the present invention is to provide a sewage pump pumping amount control method that can absorb the large fluctuations in the amount of water pumped by a sewage pump.

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 2, the sand settling basin 1, water level Coco pump 3, Ft
The flow rate and the inflow lid estimating means 5 are the same as in FIG. Here, furthermore, an inflow bar prediction means g predicts the inflow sewage cover based on the amount of inflow sewage estimated by the inflow sewage estimating means S, and a water pumping amount reference value and a water level reference value are calculated based on this predicted inflow sewage amount. It is provided with planning means t for determining. Reference numeral 7 denotes a water level feedback means for determining a pumped water amount correction value from the water level instruction value from the process and the water level reference value.

Next, a control method using the above system will be explained.

The amount of inflowing sewage is estimated by the flow device estimating means S from the flow cap meter DA and the water level meter λ, and the future inflow rate is predicted by the inflow sensitivity predicting means using the estimated value of the inflowing sewage. Various prediction methods can be considered, but as a quantitative method, there is a method using the following autoregressive model that repeatedly makes predictions.

Qln(k) = a, Qin(k-/) + a2
Qin (k-ko) +...+ anQ, 1n (k-n)
f,? IQin(k): time step k
Actual value of inflow sewage volume Q1n(k):
z + measured value a1. ...+a
ll: Autoregressive model parameter Next, using the time series of predicted values of the inflow sewage cap obtained by the flow device prediction means 1, the reference pumping amount is determined by considering the storage capacity and pumping capacity of the sewage pumping station. The method for making this determination will be explained below.

If the predicted value is used as the amount of sewage flowing into the sewage pumping station, ■ Upper and lower limit conditions for the water level of the sewage pumping station ■ Constraint conditions for the upper and lower limit conditions of the pumping capacity of the sewage pumping station, and J-W, Σ (each step water level - water level target value) 2+W
, Σ (change in pumped water amount for each step) 2-4-w, Σ
The amount of pumped water for each step can be determined so as to minimize the evaluation function (candle water f for each step) 2 (da).

However, WI m Wt b ”S is a weighting coefficient,
Σ represents calculating the sum for each valley step.

The amount of pumped water determined in this way is set as the reference value of the amount of pumped water. Furthermore, by using the predicted inflow sewage volume and this pumped water standard value, the water level standard value can be determined in the planning means γ in the following form.

x ((Predicted flow device value of the current step) - (Reference value of pumped water of the current step)) The water level reference value is corrected by feedback correction of the pump operation based on the water level indication value.

As described above, the prediction error in predicting the amount of inflowing sewage can be absorbed, and the sewage pump pumping can be controlled by appropriate pump operation correction.

In the above embodiment, an i1 meter is provided as a means for measuring the amount of pumped water, but the pressure curve flow rate characteristic of the pump may be used instead of the flow rate correction.

Alternatively, a method may be adopted in which both wave information is input into the inflow amount estimating means S of the above embodiment to improve estimation accuracy.

Furthermore, water level feedback means? It is also possible to add a function of feeding forward the estimated value of 1C and the inflow lid.

As described above, according to the present invention, it is possible to predict the amount of inflow sewage, and in order to make the prediction, the standard value of pumped water is determined by the planning function.
Since the water level reference value is determined and the prediction error is absorbed by water level feedback, it has the effect of absorbing fluctuations in the inflow sewage cover.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a device used in a conventional method, and FIG. 2 is a block diagram of a device used in an embodiment of the present invention. In the figure, / is a settling basin, ko is a water level meter, 3 is a pump, y is a flow meter, S is an inflow amount estimation means, 7 is a water level feedback means, g is an inflow amount prediction means, and ge is a planning means f. In addition, in the figures, the same reference numerals indicate the same or corresponding parts 1-0 Agent Shin Kuzuno -

Claims (2)

[Claims] (1) At a sewage pumping station, there is a stage in which the amount of inflow sewage is estimated from the water level measurements of the pump settling basin, pump well, inflow prefecture, etc. and pump equipment measurement values, and the next inflow amount is estimated from this inflow sewage sewage estimated value. a step of predicting the amount of water; and a step of determining a reference value of the amount of pumped water based on the predicted value of inflow sewage water, which is used as an evaluation function for the purpose of keeping the water level constant and suppressing changes in the amount of water pumped by the pump. A method for controlling the pumping amount of a sewage pump, comprising the step of feeding back the pumping amount reference value and the water level measurement value to obtain an operation correction lever for the pump with respect to the pumping amount reference value. (2) The sewage pump pumping amount control according to claim 7, which adds feedforward of the estimated value of inflow sewage water to the feedback of the water level measurement value in the step of determining the pump operation correction amount for correcting the pumping amount reference value. Method.