JPS63163610A - Control system for network of water distribution pipe - Google Patents

Abstract

PURPOSE:To optimize water pressure in a distribution pipe network, by deciding the target value of the water pressure so as to uniform the water pressure at each point in the distribution network based on a distribution flow rate predictor, and controlling the water pressure at each point. CONSTITUTION:At appropriate places in the distribution pipe network 3, reducing valves 4 as a means to control distribution water pressure are arranged, and a control system which controls a reducing valve controller 9 and adjusts the valve opening degree of the reducing valve 4 is constituted of a parameter setting device 10, an input device 11, an arithmetic controller 12, and an output device 13. And by performing the water pressure by predicting a distribution flow rate in future based on the data of actual distribution flow rate in the past, deciding the water pressure target value to set the water pressure at each point uniformly based on the predictor, and controlling a pressure reducing means at each point so as to coincide it with the water pressure target value, it is possible to optimize the water pressure in the distribution pipe network at each point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a water distribution pipe network control system in a water distribution facility such as a water supply facility.

(Prior art) In general, in water supply distribution facilities, the water pressure within the water distribution pipe network changes due to changes in the flow rate within the water distribution pipe network, but water pressure control always maintains the water pressure within the water distribution pipe network within the upper and lower allowable limits regardless of flow rate changes. It is necessary to keep it within 1><.

Therefore, in conventional water distribution network control systems, the water pressure in the water distribution network is controlled by measuring the water pressure at one specific point four times and comparing it with a reference pressure. I am trying to control this.

Also, assuming the outflow flow rate at the water supply point, this assumed outflow flow h)
It is also possible to control the water pressure by controlling the water pressure within the water distribution pipe network and operating the pump as a pressure source and determining the opening degree of the pressure reducing valve as the pressure reducing point to keep this water pressure within the allowable range. It is being done.

<Problems to be Solved by the Invention) However, in such a conventional water distribution pipe network control system Tlx, since the overall water pressure is controlled by looking at the water pressure at one specific point, it is difficult to control the water pressure at other points. There were problems in that the water pressure sometimes deviated from the upper and lower allowable limits, and the water pressure became too low or too high. Furthermore, since υ control is performed assuming an outflow flow rate m, there is also a problem in that it may not be possible to optimize the water pressure within the water distribution pipe network due to an error in this outflow flow rate.

In view of these conventional problems, it is an object of the present invention to provide a water distribution pipe network control system that can perform stable water pressure management of a water distribution pipe network with appropriate water pressure.

[Structure of the Invention] (Means for Solving Problems) The water distribution pipe network control system of the present invention includes a water distribution flow Iδ prediction means for predicting future water distribution flow rate from past water distribution flow rate data in the water distribution pipe network; A water pressure means for determining a water pressure target value within the water distribution pipe network at which the water pressure at each point in the water distribution pipe network is uniform based on the water distribution flow H1 prediction value of this means, and a water pressure target determined by this means. and control means for controlling the pressure reducing means at each point in the water distribution pipe network so as to match the value.

(Function) The water distribution pipe network control system of the present invention predicts future water distribution flow rate based on past actual water distribution flow rate data. Then, based on these 11 predictions of water distribution flow rate, a water pressure target value that will make the water pressure at each point in the water distribution pipe network uniform is determined,
One pressure reducing means at each point is set to match this water pressure target value.
ilJ to control water pressure and optimize water pressure at each point within the water distribution pipe network.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is a system diagram of an embodiment of the present invention, and FIG. 2 is a flowchart 1 for explaining the operation. This example relates to the water distribution pipe network of -F water supply, and includes water distribution reservoir 1.
Water is distributed from the water pipe 2 to the water pipe network 3 through the water pipe 2.

A pressure reducing valve 4 is installed at a suitable location within the water distribution pipe network 3 as a means for controlling water distribution pressure.

The water distribution reservoir 1 is equipped with a water level detector 5 for detecting its water level, and the water distribution pipe 2 is equipped with a water flow rate detector 6.
is provided.

A pressure reducing valve secondary pressure detector 7 is provided on the secondary side of the pressure reducing valve 4, and water pressure detectors 8 in the water distribution pipe network are further provided at various locations within the water distribution pipe network 3.

For each pressure reducing valve mentioned above, check the valve opening degree. A pressure reduction discrimination wl device 9 is provided as pressure reduction control means for li.

A control system for controlling the pressure reducing valve control device 9 and adjusting the valve opening degree of the pressure reducing valve 4 includes a parameter setting device 10, an input device 11, an arithmetic and control device 12, and an output device 13.

The parameter setting device 10 sets parameters such as a water pressure upper limit value δ1, a water pressure lower limit value δ2, a water pressure target value constant value href in the water distribution pipe network, and an initial value of the 31 number aO-all of the autoregressive model, and inputs the input device 11. Through the arithmetic and control unit 12
Enter.

The input device 11 receives various process values H,
Q and if are taken in, and these various variations are input to the arithmetic and control unit 12.

The arithmetic and control unit 12 uses water distribution flow as a means of predicting water distribution flow.
The predicted value is calculated and the water pressure calculation means determines the water pressure target value within the water distribution pipe network. Therefore, each of these parameters is calculated by a pre-installed program, which is constituted by, for example, a computer for pro-hysteresis control, and is outputted to the water pressure valve control device 9 of each pressure reducing valve 4 via the output device 13.

The operation of the water distribution pipe network control system having the above configuration will be explained next.

Water is distributed from the water distribution reservoir 1 to the water distribution pipe network 3 via the water distribution pipes 2. And the water level 1 of the water distribution reservoir 1 in this water distribution operation.”
, the water distribution flow ff1Q from the water distribution reservoir 1 through the water distribution pipe 2, and the water pressure at each point in the water distribution pipe network 3 are determined by the water level detector 5, the water distribution flow rate detector 6, the pressure reducing valve secondary pressure detector 7, and the water distribution pipe network, respectively. It is detected by the internal water pressure detector 8 and provided to the arithmetic and control unit 12 via the input device 11 . In addition, the arithmetic and control unit 12 receives necessary parameters from the parameter setting device 10, six upper and lower limits, δ2, and the coefficient a of the autoregressive model.
o - am , a water pressure upper limit fixed value href in the water distribution pipe network is given via the input device 11 .

The arithmetic and control device 12 performs the water pressure target value of each pressure reducing valve 4 through the arithmetic operation shown in the flowchart of FIG. 2, and outputs it to the pressure reducing valve control device 9 of each pressure reducing valve 4 via the output device 13. Then, the pressure reducing valve control device 9 adjusts the valve opening degree of the pressure reducing valve 4 according to this pressure reducing valve water pressure target value, and adjusts the valve opening degree of the pressure reducing valve 4.
By controlling the next pressure, the water pressure within the water distribution pipe network 3 is optimized.

Next, the Ω operation function in the arithmetic and control unit 2 will be explained with reference to the flowchart shown in FIG.

1iii→control*1+ The device 12 periodically inputs the process 1a) l, Q, h, etc. that changes from time to time from each detector 5-8, and also receives setting parameters δ1. from the parameter setting device 10. Input δ2, hrc(ao-am and store in internal memory (Slap 100).

Furthermore, if there is a change in the parameter setting value in the parameter setting device 10, the value of A is also taken in and stored in the internal memory of the T.

Next, the control device 12 performs a demand forecasting process (
Sudepp 110). This Ti-required prediction process is as follows.

First, the water distribution flow rate Q input from the water distribution flow rate detector 6 is integrated over a certain period of time, for example, every hour, and
(k=1-2/1)fU(7) Distribution flow m1Q(k)′? 5. Keep it clean. And for the past few days i.e. 3 mouths 1) t
The data for each day from (n −j ) to yesterday (n −1) is expressed as Qn −j (k ), Qn −j−+1<k
), --------.

Assuming that Qn-1(k), a predicted value Qn(k) of the water distribution flow rate Q during time period k of n on the day is calculated using an autoregressive model as shown in the following equation (1).

Qn (k) = ao Qn -j (k) + a
lQn-j -to1 (k) 10...+am Q
n −1(k) −=−<A) where the count a
Oam is a parameter of the autoregressive model, and is determined by the iterative method of least squares or the like.

In this way, the entire time period 1 ((k-1
-24), distribution flow m T 1tllll value Qn(k)
It is to perform.

Based on the water distribution flow forecast at δ3 during all time periods k on a particular day obtained in this way, '1lII value Qn(k),
Water distribution pipe network operation planning processing is performed to determine the pressure reducing valve water pressure target value P(k) for each time period k (Suup 12
0). When determining this pressure reducing valve water pressure target value P(k), the water pressure within the water distribution pipe network old (k) is set to the preset upper limit of water pressure within the water pipe network finδ1. Wf at each time so that the water pressure within the water distribution pipe network becomes uniform while maintaining the lower limit value δ2.
k pressure reducing valve water pressure target f+rjP(k) is determined.

In this case, the problem can be formulated as follows, for example.

Objective function Σ(11i (k) −hrcr) 2 → minimum
−・−・−(2) Constraint condition δ1>hi(k)>δ2 (i = 1. ・=
, m)...(3) f (h (k), Qn (k), r)
=O--・-(4) Here, the old (k) is the water pressure href at point i in the time period, which is the water pressure upper limit value within the water distribution pipe network (10δ1.δ2 is the water pressure upper limit value within the water distribution pipe network, the upper limit value f (h (k >,
Qn (k), r) = 0 means that the water distribution pipe network equation h(k) is the water pressure 111(k) at each point in time period k.
'), h (k )= (b+ (k
), δ2(k),..., t+n+(k)), the water distribution flow rate r during the time period is
Hamen%%'! The objective function of the above equation (2), which is derived from the equation of l l 1alls, is based on the water pressure h1 of each point i, etc. Water pipe network 3
7i with the water pressure average general constant value hrcf within! This means minimizing the sum of squares of A differences.

Here, the water pressure uniform general fixed value href in the water distribution pipe network 3 is
To decide whether to operate the water pressure at high altitudes at the lower limit of water pressure, or to operate the water pressure at lower altitudes at the upper limit, or whether to operate the water pressure at all points at the center of the upper and lower limits of water pressure. It is an evaluation value.

Furthermore, the constraint condition of equation (3) above means that the water pressure at all points is maintained within the upper and lower limit ranges.

Furthermore, the constraint condition of equation (4) means that the water pressure at each point satisfies the pipe network equation, which is the basic equation of the water distribution pipe network 3. In other words, the flow rate balance equation at each point i, the water head balance equation between points, and the conditions that the total outflow in the water distribution pipe network 3 is equal to the maximum water distribution measurement value, etc. are satisfied.

Therefore, such a problem can be solved based on nonlinear programming because the objective function and constraint '/F are nonlinear.

Then, among the water pressures (k) at all points i calculated by solving this problem, the water pressure at the point corresponding to the position of the pressure reducing valve secondary pressure detector 7 of the pressure reducing valve 4 is calculated from the pressure reducing valve secondary pressure port. fifiiP(k).

In this way, the pressure reducing valve pressure target value P (k) for each time period in a specific 10n: (k = 1-24)
It is decided.

The pressure target value P(k) determined in this way is given to the output device 13, and this output device 13 gives a command pressure to the pressure reduction control device 9 for the pressure reduction valve 4 at predetermined intervals (step 130). . Therefore, each pressure reducing valve control device 9 controls the opening degree of the pressure reducing valve 4 based on a command every predetermined time, and operates so that the water pressure in the water pipe m3 becomes uniform.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the predicted value of the water distribution flow rate for the water distribution pipe network is not based on the iterative least squares method, but is calculated using GMD I that takes into account weather factors, for example. It is also possible to use the -1 method. Furthermore, instead of controlling the water pressure within the water distribution pipe network using a pressure reducing valve, the present invention can be applied to the water pressure side of the water distribution pipe network using a water distribution pump. In this case, the discharge pressure by the water distribution pump and the water pressure at each point in the water distribution pipe wI3 1-1 (k)
Then, the discharge pressure is controlled so that the water pressure at each point is uniform.

Furthermore, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the technical idea described in the claims.

[Effects of the Invention] As described above, the present invention predicts the future distribution flow M from the past distribution flow rate data in the water distribution pipe network, and calculates the distribution flow rate at each point in the water distribution pipe network based on this water distribution flow prediction vessel. The water pressure target value is determined so that the water pressure is uniform, and the water pressure at each point is controlled to match this water pressure target value, so the water pressure at a specific point will not exceed the upper or lower allowable range. In addition, since the outflow flow rate is not assumed as in the past, there is no problem such as an error between the actual outflow flow rate and the inability to obtain the desired water pressure, and the water pressure within the pipe network can be optimized. can.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of one embodiment of the present invention, and FIG. 2 is a flow chart 11 showing the operation of the above embodiment. 1...Water reservoir 2...Water pipe 3...Water pipe network 4...Pressure reducing valve 7...Pressure reducing valve secondary pressure detector 9...Pressure reducing valve control device 10...Parameter setting Device 11...Input device 12...Performance control head 13...Output device 4U Yasuo Miyoshi

Claims (2)

[Claims] (1) A water distribution flow rate prediction means for predicting future water distribution flow rate from past water distribution flow rate data within the water distribution pipe network, and water pressure at each point within the water distribution pipe network is uniform based on the predicted water flow rate value of this means. A water distribution pipe network control system comprising: water pressure calculation means for determining a water pressure target value in a water distribution pipe; and water pressure control means for adjusting water pressure at each point so as to match the water pressure target value determined by the water pressure calculation means. (2) The water distribution flow rate prediction means calculates the predicted value of water distribution flow rate in each time period on the day of water distribution using an autoregressive model using the actual water distribution flow rate in each corresponding time period over a predetermined number of days in the past. A water distribution pipe network control system according to claim 1, characterized in that: