JP2675637B2 - Pump control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention stores sewage and rainwater flowing from a pipe in a pump well through a settling basin and a screen, and then pumps it to a sewage treatment facility. The present invention relates to a pump control device for sewage / rainwater pump equipment designed to pump water.

(Prior art) Conventionally, sewage and rainwater pump equipment in sewers is composed of a pump well and a pump group, the pump well is connected to an underground buried pipe, and the pump group has a suction side and a discharge side. Are connected to the first sedimentation basin of the sewage treatment plant. Then, the rainwater that falls in the city and the sewage discharged from homes and factories flows into the pump well through the pipe. In this case, the pump group is generally composed of a plurality of pumps, and the discharge flow rate thereof is adjusted stepwise by changing the combination of operating pumps or continuously by partial speed control or discharge valve opening control.

In general, sewage from households and factories has a certain degree of regularity depending on the activity of human groups, depending on whether the time series change is weekly or daily. However, whether the rainwater changes as a time-series change of rainfall amount by region or as the time-series change of rainwater flowing into the pump well through the pipe, it changes with each change. It is difficult to obtain a predicted value over a period sufficient to plan a pump operation plan on a daily basis or the like because it is poor in nature.

For the inflow sewage with the above characteristics, it is required to control the pump well effectively to keep the pumping volume constant for the purpose of improving the sewage treatment efficiency for sewage, while the sewage treatment for rainwater is required. For the purpose of preventing inundation of the target area of the facility, it is required to perform a quick pumping and control the drainage of inflowing rainwater to rivers.

However, conventionally, it is not possible to determine whether the sewage that is currently inflowing is only sewage, is sewage containing rainwater, that is, whether it is sewage inflow in fine weather, or sewage inflow in rainy weather, It has been difficult to perform automatic control of the pump that can cope with such conflicting purposes.

(Problems to be Solved by the Invention) As described above, conventionally, there has been a problem that pump control cannot be performed to satisfy the contradictory objectives of smoothing the water treatment load in fine weather and quickly draining water in rainy weather. .

An object of the present invention is to provide a highly reliable pump control device capable of performing pump control satisfying the contradictory objectives of smoothing the water treatment load in fine weather and quickly draining water in rainy weather. is there.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the present invention, wastewater and rainwater flowing from a pipe are stored in a pump well via a sedimentation basin and a screen, The pump control device of the sewage / rainwater pump equipment that pumps water to the sewage treatment equipment is used to detect the water level detection signal and the discharge flow rate detection signal from the water level meter installed in the pump well and the discharge flow meter installed on the discharge side of the pump. And an inflow flow rate estimated value based on the water level detection signal and the discharge flow rate detection signal input from the input means, and the change rate of the inflow flow rate estimated value and the inflow flow rate estimated value. A weather mode determination calculator that determines the weather mode of fine weather mode or rainy mode based on the deviation from the stored / updated inflow flow pattern and the rate of change of the deviation. And a fine weather mode pump control means for executing the number of pumps control and a flow rate control for the fine weather mode, and a pump control means for a rainy weather mode performing a number control of the pumps and a flow rate control for the rainy weather mode And a switching means for switching between pump control by the fine weather mode pump control means and pump control by the rainy mode pump control means according to the weather mode determined by the weather mode determination calculation means. ing.

(Operation) Therefore, in the pump control device of the present invention, the inflow flow rate estimated value is estimated and calculated from the water level of the pump well and the discharge flow rate of the pump, and the change rate of the inflow flow rate estimated value, the inflow flow rate estimated value and the storage are stored.・ Deviation from the updated inflow rate pattern,
For each of the deviation and the rate of change of the deviation, a fine weather / rainy weather mode determination value is obtained, and based on the combination of each determination value, it is decided to change to the fine weather mode, change to the rainy mode, or maintain the current weather mode. The weather mode of the clear weather mode or the rainy mode is determined, and the pump control by the pump control means for the fine weather mode and the pump control by the pump control means for the rainy mode are performed by switching according to the determined weather mode. As a result, during fine weather, the fine weather mode pump control means can control the number of pumps and the flow rate control during the fine weather mode, for example, perform constant pump discharge flow rate control to smooth the water treatment load. Then, in rainy weather, the rainwater mode pump control means controls the number of pumps and flow rate control in rainy weather mode to It is possible to perform the drainage rapid rainwater performs a constant control.

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

FIG. 1 is a diagram showing an example of a system configuration when the pump control device of the present invention is applied to control pumps in a sewage treatment plant.

In the sewage treatment plant in FIG. 1, the sewage (sewage, rainwater) flowing from the pipe 1 flows into the pump well 4 via the settling basin 2 and the screen 3 and is stored in the pump well 4. The obtained sewage is pumped to the sewage treatment facility 6 by the pump group 5. Further, a water level gauge 7 is installed in the pump well 4, and the operating range of the upper limit value 8 and the lower limit value 9 is determined for the water level. Further, a discharge flow meter 10 is attached to the discharge side of the pump group 5.

On the other hand, the pump control device 11 includes the process input / output processing unit 11
A, man-machine interface section 11B, storage section 11C
, Weather mode determination calculation unit 11D, fine weather pump control calculation unit 11E, rainy time pump control calculation unit 11F, and switching unit 11G
It is composed of

Here, the process input / output processing unit 11A inputs the water level detection signal and the discharge flow rate detection signal from the water level meter 7 and the discharge flow rate meter 10 of the sewage treatment plant, as well as a start / stop command signal and a speed control command described later. A signal (or a valve opening command signal) is output to the pump group 5 in the sewage treatment plant. In addition, the man-machine interface unit 11
B is for setting weather mode determination information and control parameters input from the CRT 12 by the operator. Further, the storage unit 11C includes weather mode determination information set from the man-machine interface unit 11B, control parameters, a water level detection signal input / output from the process input / output processing unit 11A, a discharge flow rate detection signal, and a start / stop command. The signal and the speed control command signal (or valve opening command signal) are stored.

On the other hand, the weather mode determination calculation unit 11D estimates and calculates the inflow flow rate estimated value based on the water level detection signal and the discharge flow rate detection signal input from the process input / output processing unit 11A, and further calculates the change rate of the inflow flow rate estimated value. , This estimated inflow rate and memory
The weather mode of the fine weather mode or the rainy weather mode is determined based on the deviation from the updated inflow flow rate pattern and the change rate of this deviation. In addition, the fine weather pump control calculation unit 11E includes a control parameter set from the man-machine interface unit 11B and a process input / output processing unit.
Based on the water level detection signal and discharge flow rate detection signal input from 11A, the number of pumps and flow rate control calculation for the clear weather mode are performed, and the start / stop command signal and speed control command signal (or valve opening command signal ) Is output. Furthermore, the rain pump control calculation unit 11F, based on the control parameter similarly set from the man-machine interface unit 11B, and the water level detection signal and the discharge flow rate detection signal input from the process input / output processing unit 11A,
The number of pumps for the rain mode and the flow rate control calculation are performed, and a start / stop command signal and a speed control command signal (or valve opening command signal) are output.
Furthermore, the switching unit 11G, depending on the weather mode determined by the weather mode determination calculation unit 11D, starts / stops a command signal from the pump control calculation unit 11E for fine weather mode, a speed control command signal (or valve opening degree). (Command signal), and a start / stop command signal and a speed control command signal (or valve opening command signal) from the rain mode pump control calculation unit 11F are switched and output.

FIG. 2 is a diagram showing an example of weather mode determination information set from the man-machine interface unit 11B. That is, based on this weather mode determination information, the clear / rainy weather mode determination result 13 determined from the rate of change of the estimated inflow flow rate value
And the clear / rainy weather mode determination result determined from the deviation between the estimated inflow rate and the stored / updated inflow rate pattern 14
And the clear / rainy weather mode judgment result 15 determined from the change rate of the deviation between the estimated inflow flow rate value and the stored / updated inflow flow rate pattern, the clear / rainy weather mode 16 is determined, and the clear / rainy weather mode 16 is determined. Set from the man-machine interface section 11B. In FIG. 2, (+1) indicates that the weather mode is the rain mode, (-1) indicates that the weather mode is the rain mode, and (0) indicates that the current weather mode is maintained.

Next, the operation of the pump control device having such a configuration will be described.

In FIG. 1, the water level detection signal and the discharge flow rate detection signal from the water level meter 7 and the discharge flow meter 10 installed in the sewage treatment plant are respectively input to the pump control device 11 through the process input / output processing unit 11A, and the storage unit. Remembered at 11C. The weather mode determination information and control parameters set by the operator from the CRT 12 via the man-machine interface unit 11B are also stored in the storage unit 11C. Then, in the weather mode determination calculation unit 11D, the determination calculation of the weather mode is performed based on the water level detection signal and the discharge flow rate detection signal and the weather mode determination information, and as a result, the weather mode of the fine weather mode or the rainy mode is output. It

On the other hand, the fine weather pump control calculation unit 11E performs the number of pumps control and the flow rate control calculation for the fine weather mode based on the control parameter, the water level detection signal, and the discharge flow rate detection signal. In this case, as the pump control calculation for fine weather, for example, a pump that is capable of discharging the discharge flow target value and the constant rotation speed and valve constant control by PI control in which the stored and updated inflow flow pattern is the discharge flow target value A calculation for controlling the number of units operating is performed, and in response thereto, a start / stop command signal and a speed control command signal (or a valve opening command signal) are output. Further, in the rain pump control calculation unit 11F, similarly, based on the control parameter and the water level detection signal and the discharge flow rate detection signal,
The number of pumps and the flow rate control calculation for the rain mode are performed. In this case, as the pump control calculation for rainy weather, for example, a level switch type unit control based on the operating / stop water level set value, and a calculation of the rotational speed by the PI control using the water level target value and the constant water level control by the valve are performed. Then, the start / stop command signal and the speed control command signal (or the valve opening command signal) are output in response.

Then, in the switching unit 11G, according to the weather mode determined by the weather mode determination calculation unit 11D, that is, in the clear weather mode, the start / stop command signal and the speed control command signal (speed control command signal from the clear mode pump control calculation unit 11E Or the valve opening command signal), and in the rain mode, the start / stop command signal and the speed control command signal (or valve opening command signal) from the rain mode pump control calculation unit 11F are switched and output. The command is given to the pump group 5 of the sewage treatment plant via the process input / output processing unit 11A to control the pumps.

Next, the details of the determination calculation of the weather mode of the fine weather mode or the rainy mode in the weather mode determination calculation unit 11D will be described in detail.

That is, first of all, a preset pump well structure,
The inflow flow rate at discrete times is calculated based on the water level detection signal and the discharge flow rate detection signal, and the inflow flow rate estimated value is estimated from the calculation result by the autoregressive model (step S1). The autoregressive model is a probabilistic estimation model that can represent the current value as a linear expression of values at past discrete times. Next, the fine / rainy weather mode determination result determined from the change rate of the estimated inflow rate, the fine weather / rainy mode determination result determined from the deviation between the estimated inflow rate and the inflow rate pattern, the estimated inflow rate and the inflow rate The clear weather / rainy weather mode is determined based on the weather mode determination information from the clear weather / rainy weather mode determination result determined from the change rate of the deviation from the pattern (step S2). In this case, the inflow flow rate pattern is updated and stored based on the estimated inflow flow rate value, provided that the current weather mode is the clear weather mode (step S3).

Hereinafter, each step will be described in detail with reference to the flowchart shown in FIG.

(Step S1): Inflow flow rate estimation processing The inflow flow rate q (k) at the discrete time k is calculated by (1).

q (k) = {h (k) -h (k-1)} A (h (k)) + _qout (k-1) (1) where h is the observed water level and A is The cross-sectional area of the pump well when the water level is h, and q _out is the total pump discharge flow rate.

Next, using the inflow flow rate q (k) obtained by the equation (1) as time series data, the inflow flow rate estimated value (k) is obtained based on the autoregressive model of the equation (2).

Here, x _i (i = 1, 2, ..., M) is an autoregressive model parameter (prediction coefficient), which is set in advance from a phase relation function or the like.

(Step S2): Weather mode condition calculation processing and weather mode determination processing From the current inflow flow rate estimated value q (k) and the inflow flow rate estimated value q (k−Δt) before the calculation cycle Δt, the inflow flow rate estimated value is calculated. The rate of change Δ is calculated by the equation (3).

Δ = {(k) − (k−Δt)} / Δt (3) Next, from the change rate Δ of the estimated inflow flow rate obtained by the equation (3), the determination value DΔ is obtained by the equation (4). Required by.

If Δ ≧ Δ _inc, then DΔ = + 1 Δ _dec <Δ <Δ _inc, then DΔ = 0 ... (4) If Δ ≦ Δ _dec, then DΔ = −1 where Δ _inc and Δ _dec are set in advance. These are the increase rate threshold and the decrease rate threshold of the estimated inflow rate.

Next, the current estimated inflow rate (k) and the calculation cycle Δ
Estimated inflow rate (k- [Delta] t) before t, and current corresponding inflow rate pattern qp (k ') whose details will be described later.
And the inflow flow rate pattern qp (k'-Δ before the calculation cycle Δt
From t), the deviation dqp and the change rate Δdqp of the deviation between the estimated inflow flow rate and the inflow flow pattern are obtained by the equations (5) and (6), respectively.

dqp = (k) −qp (k ′) (5) Δdqp = [{(k) −qp (k ′)} − {(k−Δt) −qp (k′−Δt)}] / Δt ... (6) Next, from the deviation dqp and the deviation change rate Δdqp obtained by the expressions (5) and (6), the determination values Ddqp and DΔdqp are respectively calculated by the expressions (7) and (8). .

Here, dqp +, dqp−, Δdqp _inc , and Δdqp _dec are the deviation positive threshold value, deviation negative threshold value, and
These are a deviation increase rate threshold value and a deviation decrease rate threshold value.

Next, the weather mode is determined based on the weather mode determination information for the combination of the determination values DΔ, Ddqp, DΔdqp obtained by the equations (4), (7), and (8). As an example using the weather mode determination information shown in FIG. 2, if DΔ = + 1, Ddqp = + 1, DΔdqp = + 1, D = + 1, that is, the weather mode is determined to be the rain mode, and DΔ = -1, Ddqp = -1, D [Delta] dqp = -1, it is decided that the weather mode is the clear weather mode. In addition, other weather mode is rainy weather mode (D = + 1)
In this case, there are combinations of DΔq = 0, Ddqp = + 1 and DΔdqp = + 1.

Similarly, in addition to the weather mode, fine weather mode (D = -1)
As the case of, the combination of DΔq = −1, Ddqp = 0, DΔdqp = 0, the combination of DΔq = −1, Ddqp = 0, DΔdqp = −1, the combination of DΔq = −1, Ddqp = −1, DΔdqp = 0 combination.

(Step S3): Inflow flow pattern update / storage processing Provided that the current weather mode is the clear weather mode,
The inflow flow rate pattern qp is updated and stored. In this case, for example, if the inflow flow rate pattern period is one day (= 1440 minutes), the calculation period Δt = 1 minute, and the weighted average method is used as the update method, the update operation expression becomes as shown in expression (9). .

Here, α is 0 ≦ α ≦ 1, which is a preset weighted average calculation coefficient.

As described above, in the pump control device 11 of this embodiment,
Estimated calculation of inflow rate from the water level detection signal from the water level gauge 7 installed in the pump well 4 of the sewage treatment plant and the discharge flow rate detection signal from the discharge flow meter 10 installed on the discharge side of the pump group 5. In addition, from the change rate of the estimated inflow rate, the deviation between the estimated inflow rate and the stored / updated inflow rate pattern and the change rate of the deviation, the weather mode of the clear weather mode or the rain mode is determined, and Depending on the determined weather mode, you can switch between pump control by the pump control calculation for fine weather mode (number control and constant flow rate control) and pump control by pump control calculation for rainy mode (number control and constant water level control). The pump control is performed.

Therefore, it is possible to perform a constant flow rate control during smooth weather to smooth the water treatment load, and to perform a constant water level control during rapid rain to quickly drain rainwater. This makes it possible to satisfy the contradictory objectives of smoothing the water treatment load in fine weather and quick drainage of water in rainy weather.

In the above embodiment, the equations (4), (7),
The determination condition of the equation (8) is a condition of only the calculation period, but as a noise filter method, when a plurality of determination conditions are continuously satisfied, it is (+1) or (-1), and the others are A method such as (0) can be adopted.

In addition, in the above embodiment, the inflow flow rate pattern update /
In the storage process, a method of updating and storing for each calculation cycle and smoothing by a method such as linear interpolation at the time of obtaining the deviation can be adopted. Then, if the purified water distribution flow rate to the inflow sewage area can be measured, the sewage inflow rate can be estimated by statistical calculation by adding time delay, underground penetration, etc. to the purified water distribution flow rate. The flow rate of purified water distribution can be reflected in the pattern on both the flow axis and the time axis.

[Effects of the Invention] As described above, according to the present invention, the estimated inflow rate is calculated from the water level of the pump well and the discharge rate of the pump, and the change rate of the estimated inflow rate and the estimated inflow rate are calculated. Based on the deviation between the stored and updated inflow flow pattern and the rate of change of the deviation, the weather mode of the clear weather mode or the rainy mode is determined, and the pump control for the clear weather mode is performed according to the determined weather mode. By controlling the pump control by means and the pump control by means of the rainwater mode pump control means, it is possible to satisfy the conflicting purposes of smoothing the water treatment load in fine weather and quick water distribution in rainy weather. An extremely reliable pump control device capable of performing pump control can be provided.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment in which a pump control device of the present invention is applied to control pumps in a sewage treatment plant, and FIG. 2 is a diagram showing an example of weather mode determination information in the same embodiment. FIG. 3 is a flow chart for explaining the determination calculation contents of the weather mode in the same embodiment. 1 ... pipe, 2 ... sedimentation basin, 3 ... screen, 4 ...
Pump well, 5 ... Pump group, 6 ... Sewage treatment facility, 7 ...
… Water level meter, 10 …… Discharge flow meter, 11 …… Pump control device,
11A: Process input / output processing section, 11B: Man-machine interface section, 11C: Storage section, 11D: Weather mode determination calculation section, 11E: Sunny weather pump control calculation section, 11F: Rainy weather pump control calculation section Section, 11G ... Switching section, 12 ... CRT.

Claims (1)

(57) [Claims] 1. A pump control device for sewage / rainwater pump equipment, wherein sewage and rainwater flowing from a pipe are stored in a pump well through a sedimentation basin and a screen and pumped to a sewage treatment equipment by the pump. Input means for respectively inputting a water level detection signal and a discharge flow rate detection signal from a water level meter provided in the pump well and a discharge flow meter provided on the discharge side of the pump, and a water level detection signal input from the input means, The estimated inflow flow rate is estimated and calculated based on the discharge flow rate detection signal, and the change rate of the estimated inflow flow rate, the deviation between the estimated inflow flow rate and the stored / updated inflow rate pattern, and the change rate of the deviation Based on, the weather mode judgment calculation means for judging the weather mode of the clear weather mode or the rainy weather mode, the number of pumps control for the clear weather mode, and the flow rate For controlling the number of pumps in the rain mode, for controlling the number of pumps in the rain mode, and for controlling the flow mode in the rain mode, and the weather determined by the weather mode determination calculation means. A pump control device comprising: switching means for switching between pump control by the pump control means for the fine weather mode and pump control by the pump control means for the rainy mode according to the mode.