JPH03115786A - Pump control device for sanitary sewage pump equipment - Google Patents

Abstract

PURPOSE:To improve the sewage treatment efficiency by estimating a flow quantity of the sewage per specified cycle with the measured water level and the discharging quantity to automatically form a discharging flow quantity pattern. CONSTITUTION:In a pump control device 11 of a sewage treatment pump equipment 1, a discharging flow quantity pattern computing unit 19 estimates and computes a flowing quantity of the sewage per specified cycle with the water level and the discharging flow quantity detected by a water level gauge 9 of a pump well 4 and a discharging flow quantity meter 10 for detecting a discharging flow quantity from a pump 6 to a sewage treatment equipment 8. A flowing quantity pattern is renewed with this estimation-computed flowing quantity. A flowing quantity pattern is computed with a flowing quantity pattern after a renew, and this pattern is stored in a discharging flow quantity pattern memory 20. A pump drive control unit 21 reads out the discharging flow quantity pattern stored in the memory 20, and controls each pump 6 through a process input/output treatment unit 12 so that the discharging flow quantity detected by the discharging flow quantity meter 10 coincides with the discharging flow quantity of the cycle, to which the actual time belongs, within the discharging flow quantity pattern.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention relates to sewage pump equipment in a sewage system, and in particular, to smoothing out the load on sewage treatment equipment by minimizing changes in pump discharge volume. The present invention relates to a pump control device for sewage pump equipment designed to achieve the following.

(Prior Art) Generally, sewage pump equipment in a sewage system consists of a pump well and a group of pumps.

Then, wastewater flows into the pump well from underground pipes and is temporarily stored in this pump well. The stored wastewater is transferred to the sewage treatment facility by each pump.

In this case, the pump group generally consists of multiple pumps,
The total discharge flow rate can be adjusted stepwise by changing the combination of operating pumps, or continuously by controlling the speed of some pumps or controlling the opening of the discharge valve.

In addition, the amount of sewage discharged from general households and factories changes over time depending on lifestyle patterns and factory production patterns over a predetermined period of time, such as one day (24 hours) or one week (7 days). Internally, it changes in a somewhat fixed pattern. On the other hand, as a sewage treatment facility,
Sewage can be treated most efficiently when a constant amount of sewage continues to flow in at all times. Therefore, even if the amount of wastewater discharged changes significantly, it is preferable that the flow rate of wastewater flowing into the sewage treatment facility does not change frequently.

Therefore, in sewage pump equipment, the amount of water stored in the pump well is increased to absorb fluctuations in the amount of inflow sewage.

However, it is practically difficult to set the water storage capacity of the pump well to a capacity that can absorb changes in the inflow flow rate of sewage.
A water level gauge is attached to the pump well to control the water level so that it is between the upper and lower water levels. In other words, the pump discharge flow rate is changed according to the current water level, and when the water level exceeds the upper limit water level, the pump discharge flow rate is set to the maximum within the allowable range of the sewage treatment equipment, and when the water level falls below the lower limit water level, The discharge amount of the pump is set to a minimum value so that the water level quickly returns between the upper and lower limits.

However, since the pump discharge rate is controlled based on the current water level detected as described above, if the flow rate of wastewater flowing into the pump well fluctuates as described above, the pump discharge rate will constantly change. .

Furthermore, the water level approaches the upper limit water level or the lower limit water level more frequently. Therefore, the flow rate of sewage flowing into the sewage treatment facility fluctuates, resulting in the problem that sewage treatment is not performed efficiently.

(Problem to be Solved by the Invention) As described above, according to the conventional pump control device for sewage pump equipment, the discharge flow rate of the pump is changed according to the current water level change detected by the water level meter. , the discharge flow rate of the pump frequently fluctuates, the load on the sewage treatment equipment increases, and the problem arises that sewage treatment is not carried out efficiently.

The present invention has been made in view of the above-mentioned circumstances, and by estimating the inflow flow of sewage at regular intervals from the determined water level and discharge flow rate and automatically creating a discharge flow rate pattern, Pumps for sewage pump equipment that can smooth out changes in the pump's discharge flow rate, suppress load fluctuations in sewage treatment equipment, and improve sewage treatment efficiency because the pump discharge flow rate can be set at regular intervals regardless of the current water level. The purpose is to provide a control device.

[Configuration of the Invention (Means for Solving the Three Problems) In order to solve the above problems, the pump control device of the sewage pump equipment of the present invention temporarily stores the sewage flowing in from the pipe in the pump well, and then the pump In sewage pump equipment that uses a pump to transfer sewage stored in a well to a sewage treatment facility, an inflow flow rate pattern that stores the inflow flow rate pattern of sewage flowing into a pump well at predetermined intervals within a predetermined period of time. From the storage unit, a water level meter that detects the water level of the pump well, a discharge flow meter that detects the discharge flow rate from the sewage pump to the sewage treatment equipment, and the water level and discharge flow rate detected by the water level meter and discharge flow meter. Inflow flow rate estimating means for estimating and calculating the flow rate of sewage flowing into the pump well at regular intervals;
An inflow flow rate pattern updating means updates the inflow flow rate pattern with the inflow flow rate for each specified period obtained by the inflow flow rate estimating means, and calculates an optimal discharge flow rate pattern for each specified period using the updated inflow flow rate pattern. and a pump drive control section that drives and controls the pump so that the discharge flow rate matches the discharge flow rate pattern calculated and stored in the discharge flow rate pattern calculation storage means. be.

(Function) According to the pump control device for sewage pump equipment configured in this manner, the inflow flow rate of sewage is estimated and calculated at each prescribed period from the water level and discharge flow rate detected by the water level meter and the discharge flow meter. Then, the inflow flow rate pattern is updated with the inflow flow rate calculated by this estimated eL. A discharge flow rate pattern is calculated using the updated inflow flow rate pattern, and the pump is driven and controlled based on this discharge flow rate pattern.

The discharge flow rate pattern, which is the basis for driving and controlling this pump, is determined from the inflow flow rate pattern. The value of this inflow flow rate pattern changes every prescribed period. That is, by setting the value of the specified period to, for example, 1 hour to 2 hours, frequent changes in the discharge flow rate can be suppressed.

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

FIG. 1 is a schematic diagram showing a pump control device according to an embodiment and sewage pump equipment driven by this pump control device. 1 in the figure is a sewage pump facility, and sewage discharged from general households and factories flows into a settling basin 3a in the pump facility 1 through a buried pipe 2, and is pumped through a rough screen 3b. Water flows into well 4 and is temporarily stored. and,
The sewage stored in the pump well 4 is sucked into the pump 6 through a plurality of suction pipes 5, and a single discharge pipe 7 is used in common.
The water is then discharged to the first water tank in the sewage treatment facility 8. A water level gauge 9 is installed in the pump well 4, and a discharge flow meter 10 is inserted in the discharge pipe 7 to detect the discharge flow rate per unit time.

Then, the water level h1 of the water level gauge 9 and the discharge flow of the discharge flow meter 10!
q and the rotation speed of each pump 6 are input to the process input/output processing section 12 of the pump control device 11. This process input/output processing section 12 sends output control signals such as the number of pumps in operation and speed control to each pump 6.

As shown in the figure, the pump control device 11 includes a CRT display section 13 and a man-machine interface section 15 through which an operator inputs various setting data in an interactive manner. The control parameter memory 17 stores the pump well structure 1 pipe conduit structure preset by the operator via this man-machine interface section 15, various calculation constraint conditions for calculating the discharge flow rate pattern, and the process input/output. Processing section 12
A process state memory 18, a control parameter memory 17, and a process state memory 18, which temporarily stores the status of water level, discharge flow ffi q, rotation speed 1, operation/stop, start/stop, start-up completion, etc. of each pump 6 inputted through the state memory 18
A discharge flow rate pattern calculation section 19 that calculates the discharge flow rate pattern TQP from each data of the discharge flow rate pattern calculation section 19, a discharge flow rate pattern storage section 20 that temporarily stores the discharge flow rate pattern TQP calculated by this discharge flow rate pattern calculation section 19, and this discharge flow rate pattern TQP. and a pump drive control section 21 that sends out various signals for driving and controlling each pump 6 from the process state of the process state memory 18, and a buffer that temporarily stores start/stop commands and speed control commands output from the pump drive control section 21. It is composed of circuits 22, 23, etc.

Further, as shown in FIG. 2, the discharge flow rate pattern calculation section 19 performs an inflow flow rate estimating section 19a1 estimating the inflow flow faSQ of sewage into the pump well 4 from the input discharge flow rate q and water level. An inflow flow rate pattern update/storage unit 1 that calculates an inflow flow rate pattern SQP from the inflow flow m S Q and updates the previous (previous II) inflow flow rate pattern SQP stored in the inflow flow rate pattern storage unit 19d.
9b1 consists of a discharge flow rate pattern calculation/storage unit 19c that calculates a discharge flow rate pattern TQP based on this updated inflow flow rate pattern SQP and stores it in the discharge flow rate pattern storage unit 20.

Next, the operation of each part of this pump control device 11 will be explained in order.

First, before operating the sewage pump equipment f11, the operator 14
The above-mentioned FiLIJ parameters are set in the control parameter memory 17 via the man-machine interface unit 16. In addition, the discharge flow rate pattern storage section 2
0 is set to, for example, the approximate value of the discharge amount pattern TQP for 24 hours a day.

Then, when the pump control device 11 is started, the pump drive control section 21 drives and controls each pump 6 via the buffer circuit 2223 and the process input/output processing section 12 according to the discharge flow rate pattern TQP of the discharge flow rate pattern storage section 20. do. Therefore, the discharge flow mq of wastewater flowing into the sewage treatment facility 8 via the discharge pipe 7 changes in accordance with the discharge flow rate pattern TQP.

Process information such as the water level of the sewage pump device 1, the discharge flow rate q, and the rotation speed RPM of the water pump is sequentially stored in the process state memory 18 via the process input/output processing section 12.

In such an operating state, the inflow flow rate estimation section 19a of the discharge flow rate pattern calculation section 19 estimates the inflow flow rate SQ of wastewater into the pump well 4 according to the following procedure.

First, the inflow flow rate q (k) at a discrete time k is expressed as the measured water level h (k) at that time k and the discharge flow mq (k, -1) measured at the previous time (k-1).
) is used to calculate the equation (1).

q (k) = l h (k) −h (k-1)I
A (h) + q (k-1) ・
...(1) However, A(h(k)) is the cross-sectional area of the pump well 4 at the water level. Note that each company's conditions for calculating the inflow flow rate, such as the cross-sectional area of the pump well 4, are read from the control parameter memory 17.

Using the inflow flow m q (k) obtained by equation (1) as time series data, the estimated inflow flow rate S Q (k) is determined by the autoregressive model of equation (2).

Note that x + (i −1, 2, 3, −= , lI)
is the parameter of the self-feedback model. Further, in the embodiment, the discrete time k is set, for example, every minute.

Next, the operation of the inflow flow rate pattern updating/recording section 19b will be explained. Here, the input estimated inflow flow ffi S
The inflow flow rate pattern SQP (T) is calculated from Q (k), and the inflow flow rate pattern 5QP (T) of the previous day stored in the inflow flow rate pattern storage section 19d is updated. In this embodiment, as described above, the entire period of the inflow flow rate pattern SQP (T) is one day, and the integrated value of the inflow flow rate, that is, the specified period T, is set to one hour.

(T-0,1,,2,...123).

Then, the inflow flow m (inflow flow rate for one hour at 7 o'clock) SQ (T) within an arbitrary period T is expressed by equation (3).

ζq However, q(T+Δt) is T hour Δ in minutes (1)
This is the estimated inflow flow rate calculated using the formula.

Therefore, the value of the inflow flow rate pattern SQP (T) in the cycle T of f1 is set in advance by setting the value in the same cycle T before 11.1 to SQP (T)F, and α is a value from 0 to 1. If it is added as ffl1'-equalization coefficient, it can be obtained by equation (4).

SQP (T) - α5Q (T) + (1-a) SQP (T) p ... (4) The value 5QP (T) p in the same cycle T one day ago is stored in the inflow flow rate pattern storage section 19d. has been done.

The flow rate pattern SQP (T) of the flow of people in each period T calculated in this manner has a waveform shown in, for example, FIG. 2 or FIG. 4. Then, the inflow flow rate pattern storage section 19d
The value 5QP(T)p of the corresponding period T within is updated with the value SQP(T) of the inflow flow rate pattern calculated in the current period T.

Next, the operation of the discharge flow rate pattern calculation/storage section 19c will be explained. Here, a smoothed discharge flow rate pattern TQP (T) is calculated using the updated inflow flow rate pattern 5QP (T) stored in the inflow flow rate pattern storage section 19d, and is set in the discharge flow rate pattern storage section 20. do.

There are various methods for calculating the discharge flow rate pattern TQP (T) from this inflow flow rate pattern 5QP (T), but each method is tried every cycle T according to the discharge flow rate pattern calculation constraints set in the control parameter memory 17. I'm going to do it by mistake.

In principle, for each period T, the value of the discharge flow rate pattern (
discharge flow rate). Then, the value of this discharge flow rate pattern (discharge flow rate) is maintained during the next cycle (T + 1).

Then, the discharge flow rate pattern TQP (T) in each period T is sequentially set in accordance with the above-described procedure, but in addition to this, various discharge flow rate parameter calculation constraints are set in the control parameter memory 17.

For example, as the first constraint, the discharge flow rate pattern TQ
The discharge flow rate of P (T) is a specified amount T set in advance at one time.
Changes by s. That is, the inflow flow rate pattern SQP
Only when (T) changes by more than this specified amount Ts, the discharge flow rate of the discharge flow rate pattern TQP (T) changes to the specified value In.
It changes by T s. Therefore, the inflow flow rate pattern S
When QP (T) changes significantly, the discharge flow rate of the discharge flow rate pattern TQP (T) changes by a specified amount T over a plurality of periods T.

As a second constraint, it is of course prohibited that the water level in the pump well 4 exceeds the upper limit H or falls below the lower limit. Specifically, the calculated discharge flow ff of each period T
When the pump 6 is operated for the current cycle T or the next cycle T at 1TQP(T), the water level at the end of each cycle T is equal to the water level h (T) at the end of the previous cycle T.
-1>, the constant inflow flow fnsQ (T) and the cross-sectional area A (h) in the current period T, so if the calculated water level is outside the above range, the discharge flow rate calculated this time is is canceled, returns to the previous cycle (T-1), and calculates the discharge flow rate again.

FIG. 2 is a diagram showing the relationship between the inflow flow rate pattern SQP (T) and the calculated discharge flow rate pattern TQP (T), and the second diagram is a diagram showing the relationship between the inflow flow rate pattern SQP (T) and the calculated discharge flow rate pattern TQP (T).
) is a diagram showing the water level h (T) calculated based on.

First, the primary discharge flow rate pattern TQP (T) is started at a point in the figure, and the discharge flow rate for each cycle T is sequentially set based on the above-described first constraint condition.

At the same time, the water level h (T) at the end of each period T is calculated in sequence. Then, this primary discharge flow rate pattern TQ
P (T) gets stuck at 0 points. In other words, at point 0, the water level h (T) exceeds the upper limit water level H, as shown in Figure 4. This is the primary discharge flow rate pattern TQP
At (T), the timing to start increasing the discharge flow rate was delayed, so the water level h (T) exceeded the upper limit water level H.

Therefore, the flow returns from the 0 point to the 0 point before one rotation, and the calculation of the secondary discharge flow rate pattern TQP (T) is started. However, even in this secondary discharge flow rate pattern TQP (T), the water level h (T) exceeds the upper limit water level H at the 0 point. Therefore, it is necessary to start increasing the discharge flow rate earlier.

Then, it returns to the 0 point one cycle before the 0 point and starts calculating the tertiary discharge flow rate pattern TQP (T). However, this tertiary discharge flow rate pattern TQP (T is the water level h (T)
did not exceed the upper limit water level H, but this time it falls below the lower limit water level at point [F]. That is, it is necessary to start reducing the discharge flow rate earlier.

Thus, calculation of the fourth-order discharge flow rate pattern TQP (T) is started from the 0 point, which is moved one cycle before the decrease start time. In this fourth-order discharge flow rate pattern TQP (T), the water level h (, T) falls between the upper limit water level H and the lower limit water level during the period until the final cycle T-24 (0). .

Therefore, 1, which is a combination of the 1st, 3rd and 4th order discharge flow rate patterns TQP (T) with the daily inflow flow rate pattern SQP (T) from 0:00 to 23:00, is 1st, 7:00 to 14:00. A tertiary discharge flow rate pattern TQP(T) is incorporated from 14:00 to 0:00, and a quartic discharge flow rate pattern TQP(T) is incorporated from 14:00 to 0:00.

The discharge flow rate pattern TQ calculated through trial and error in this way
P (T) is stored in the discharge flow rate pattern storage section 20.

Then, the discharge flow rate pattern TQP (T) stored in the discharge flow rate pattern storage section 20 is read out by the pump drive control section 21. Then, the pump drive control unit 21 controls the process so that the discharge flow; Each pump 6 is driven and controlled via the input/output processing section 12.

In the pump length control device for sewage pump equipment configured in this way, the discharge flow rate of each pump 6 is controlled according to the discharge flow rate pattern TQP(T) shown in FIG.

Therefore, as shown in the figure, this discharge flow rate pattern TQP (T) is maintained at the same discharge flow rate for as long as possible, and when changing the discharge flow rate, it is increased or decreased by a predetermined amount Ts. I'm letting you do it.

Therefore, the number of times the flow rate of wastewater flowing into the sewage treatment facility 8 changes within a predetermined period such as one day is significantly reduced compared to the conventional case where the flow rate changes in response to the current water level. Further, the inflow flow rate changes in stages, and the number of stages can be reduced by setting the prescribed HTs in FIG. 2 to a large value.

As a result, sewage treatment efficiency in sewage treatment equipment can be significantly improved.

Note that the present invention is not limited to the embodiments described above. In the embodiment, each stream Evaturn SQP, TQP
Although the entire period of the period is set to 10 (24 hours), it may be set to, for example, one week.

Further, although the prescribed period T is set to 1 hour, it may be set to 10 or 30 minutes, for example.

Further, the discharge flow rate pattern calculation constraint conditions for calculating the discharge flow rate pattern can also be changed arbitrarily as necessary.

[Effects of the Invention] As explained above, according to the pump control device for sewage pump equipment of the present invention, the inflow flow rate of sewage is estimated every prescribed period from the 10+ determined water level and discharge flow rate, and the inflow flow rate pattern is determined. Furthermore, by adding various constraint conditions to this inflow rate pattern, an optimal discharge flow rate pattern is automatically created so that the discharge flow rate does not change as much as possible. and,
The pump is driven and controlled so that the actual discharge flow rate matches the discharge flow rate pattern. Therefore, the pump discharge flow rate can be set at regular intervals regardless of the current water level in the pump well, so changes in pump discharge flow rate can be smoothed, load fluctuations in sewage treatment equipment can be suppressed, and sewage treatment efficiency can be improved. .

[Brief explanation of drawings]

The figure shows a pump control device according to an embodiment of the present invention, and FIG. 1 is a schematic diagram showing a pump control device and sewage pump equipment driven by this pump control device, and FIG. 2 shows main parts. FIG. 3 and FIG. 5 are diagrams showing the calculated inflow flow rate pattern and discharge flow rate pattern, and FIG. 4 is a diagram showing the calculated water level. 1...Sewage pump equipment, 2...Pipe culvert, 4...Pump well, 6...Pump, 8...Sewage treatment equipment, 9...
- Water level meter 10...Discharge flow meter, 11...Pump control device, 12...Process input/output processing section, 17...Control parameter memory, 19...Discharge flow rate pattern calculation section, 19a... - Inflow flow rate estimating section, 19b... Inflow flow rate pattern update Φ storage section, 19C... Discharge flow rate pattern calculation/storage section, 19d... Inflow flow rate pattern storage section, 20... Discharge flow rate pattern storage section, 1... Pump drive control section.

Claims (1)

[Scope of Claims] In a sewage pump facility in which sewage flowing in from a pipe is temporarily stored in a pump well, and the sewage stored in the pump well is transferred to a sewage treatment facility using a pump, the sewage flows into the pump well. an inflow flow rate pattern storage unit that stores an inflow flow rate pattern for each predetermined cycle within a predetermined period of sewage, a water level gauge that detects the water level of the pump well, and a flow of the sewage from the pump to the sewage treatment equipment. a discharge flow meter that detects the discharge flow rate of the pump well, and an inflow flow rate estimation that estimates and calculates the inflow flow rate of sewage flowing into the pump well from the water level and discharge flow rate detected by the water level meter and the discharge flow meter. an inflow flow rate pattern updating means for updating the inflow flow rate pattern with the inflow flow rate for each specified period obtained by the inflow flow rate estimating means; a discharge flow rate pattern calculation storage means for calculating and storing an optimum discharge flow rate pattern; and a pump drive for driving and controlling the pump so that the discharge flow rate matches the discharge flow rate pattern calculated and stored in the discharge flow rate pattern calculation storage means. A pump control device for sewage pump equipment, which is equipped with a control unit.