JPS5944644B2 - Water reservoir operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water distribution reservoir operation method, and particularly to a water distribution reservoir operation method suitable for operating a water supply system consisting of a water purification plant, a water distribution reservoir, and a pipe network connecting these.

In the conventional water reservoir operation method, a certain upper and lower limit of the water level in the reservoir is established, and a water supply plan is established to ensure that the water level does not exceed this.
If an error occurred in the plan and the water level exceeded the upper and lower limits of the reservoir, the system used was to increase or decrease the amount of water received by the reservoir to maintain the upper and lower limits of the water level of the reservoir.

However, with this method, when the water level of each distribution reservoir approaches its limit at the same time, there is little room to modify the amount of water received by the distribution reservoir.
It is difficult to maintain the upper and lower limits of water level in the reservoir. Furthermore, once the water level in the reservoir exceeds the upper and lower limits, it is possible that the water level in the reservoir will frequently exceed the upper and lower limits and the amount of water received by the reservoir will need to be corrected. This was not desirable both from the viewpoint of maintaining the upper and lower limits of the water level in the reservoir and from the viewpoint of simplifying the operation. An object of the present invention is to eliminate the drawbacks of the prior art described above, to easily modify the amount of water received by a water distribution reservoir, and to provide an efficient water distribution reservoir that does not require any modification for a while after the modification is made. The objective is to provide a new water reservoir operation method that enables the operation of water distribution reservoirs.

The features of this invention include the upper and lower limits of the water distribution reservoir water level to be observed when making an operation plan based on demand forecasts, the upper and lower limits of the water distribution reservoir water level when determining whether to modify the operation plan, and the upper and lower limits of the water distribution reservoir water level when determining whether to modify the operation plan. Sometimes, by setting the target upper and lower limits of the water level in the reservoir to different values, the possibility of exceeding the upper and lower limits of the water level in the reservoir is reduced, and once the upper and lower limits of the water level in the reservoir are exceeded, the operation plan is revised. The next step is to operate the reservoir in such a way that there is no need to revise the operation plan for the time being.

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

FIG. 1 shows a water supply system to which the present invention is applied and a block diagram of its operation method. 1 in Figure 1 is a water treatment plant,
2 to 4 are water pipes, 5 to 7 are water reservoirs, 8 to 1
0 is a water distribution pipe network, 11 to 13 are inflow flowmeters, 14 to 16 are valves, 17 to 19 are water distribution reservoir inflow control devices, 20 to 22 are water level meters, 23 to 25 are water distribution flowmeters, 26 to 28 is a pump, 29 to 31 are pressure gauges, 32 to 34 are water distribution pump control devices, 35 is a storage device, 36 is a water distribution amount prediction device, 37 is a water transmission/reception amount planning device,
38 is a water quantity command device, 39 is a water distribution quantity monitoring device, 40 is a water distribution quantity prediction correction device, 41 is a water distribution reservoir water level prediction device, 42 is a water distribution reservoir water level determination device, 43 is a water transmission/reception amount plan modification device, 4
4 is a water reservoir water level monitoring device, and 45 is a water reservoir water level upper and lower limit setting device. The water reservoir operation method will be explained with reference to Figure 1.

First, the water distribution reservoir water level upper and lower limits setting device 45 sets the water distribution reservoir water level upper and lower limits (Hl, L
l), the upper and lower limits of the water distribution reservoir water level (H3, L3) when determining whether to modify the water transmission and reception plan, and the upper and lower limits of the target water distribution reservoir water level (H2, L) when modifying the water transmission and reception plan.
2) is set for each reservoir. As shown in Figure 2, the upper and lower limits of these three water distribution reservoir water levels are H1〈H2〈H3,
Set so that Ll>L2>L3. Here, Hi
is the upper limit of the water level in the water distribution reservoir, and L1 is the lower limit of the water level in the water distribution reservoir. 1st
Water level gauges 20 to 22 and water distribution flow meters 23 to 25 in the figure
The measured values are periodically sent to and stored in the storage device 35.

When making a water transmission/reception plan for the next day, first, the water distribution amount prediction device 36 is activated, takes out the past water distribution amount actual value from the storage device 35, and predicts the next day's water distribution amount based on this. For example, the simplest method is to predict the next day's water distribution amount for each time period based on the average value of the water distribution amount for each time period for the past three days. In other words, the predicted water distribution amount for n hours of the next day is
Ln. If the actual water distribution amount value for the n time period 1 days ago is LO, then 1Ln=(1, Ln+-2Ln+1).

Ln)/3n20,1,...,23.

This predicted water distribution amount for the next day is sent to the storage device 35, and the water transmission/reception amount planning device 37 is activated. The water transmission/reception amount planning device 37 uses the predicted water distribution amount for the next day and the upper and lower limits Hl of the water level in the water distribution reservoir previously set by the upper and lower limit setting device 45 for the water level in the water distribution reservoir.
, Ll to plan the amount of water to be sent and received from water pipes 2 to 4 for the next day. For example, the average amount of water sent and received per day is calculated, the water level of the water distribution reservoir at that time is predicted, and when the water level of the water distribution reservoir exceeds the upper and lower limit values Hl and Ll of the water distribution reservoir water level, the amount of water sent and received is corrected. That is, let Yn be the amount of water received during the n time period on the next day.

The water level of the distribution reservoir during n hours, Hn, is the initial water level, HO
lIf the area of the water distribution reservoir is A, then

If the water level of the water distribution reservoir predicted in this way exceeds the upper and lower limits Hl, Ll of the water level of the water distribution reservoir, the water transmission/reception amount is corrected and a water transmission/reception plan is made so as not to exceed the upper and lower limits H1, Ll of the water level of the water distribution reservoir. This water transmission/reception amount plan and the predicted water level of the distribution reservoir are stored in the storage device 3.
5 and sends it to the water amount command device 38. The next day, the water quantity command device 38 gives this water transmission/reception quantity plan to the water distribution reservoir inflow control devices 17 to 19 at the entrance of each water distribution reservoir as a flow rate command value for each time period.

The water reservoir inflow control devices 17 to 19 are constituted by well-known PID control devices, etc., and open and close the valves 14 to 16 so that the measured values of the inflow flowmeters 11 to 13 match the flow rate command values.

The measured values of the water distribution flowmeters 23 to 25 are periodically sent to and stored in the storage device 35, and are also sent to the water distribution amount monitoring device 39.
is also sent to start this.

The water distribution amount monitoring device 39 compares the measured values of the water distribution flowmeters 23 to 25 with the water distribution amount predicted value stored in the storage device 35, and starts the water distribution amount prediction correction device 40 when this difference exceeds an allowable value. do. The water distribution amount prediction correction device 40 corrects the predicted water distribution amount for the following day based on the water distribution amount predicted value stored in the storage device 35 and the water distribution amount actual value up to that day. For example, when modifying at time n,
0L1 is the actual value of water distribution amount for l time period of the day, and the predicted value of water distribution amount is 0L1.

Assume that Li and the corrected value of the predicted water distribution amount are 0Li.

This corrected value of the water distribution amount predicted value is sent to the storage device 35 to update the previous water distribution amount predicted value, and at the same time, the water distribution reservoir water level prediction device 41 is activated. The water reservoir water level prediction device 41 is the storage device 3
The current water level, future water transmission/reception volume plan, and predicted water distribution volume are extracted from 5 to predict the water level of the distribution reservoir.

In other words, the water level in the water reservoir in time zone j is 0hJ1, and the water level in the water reservoir at the moment is 0hn. If the amount of water received during time i is 0Yi,
becomes. Then, this water distribution reservoir water level prediction value is stored in the storage device 35.
At the same time, the water distribution reservoir water level determination device 42 is activated. Reservoir water level determination device 42 compares this predicted value of reservoir water level with upper and lower limits H3 and L3 of reservoir water level set by reservoir water level upper and lower limits setting device 45, and determines whether the reservoir water level is within the upper or lower limits of reservoir water level. When the amount exceeds the amount, the water transmission/reception amount plan correction device 43 is activated.

The water transmission/reception amount plan correction device 43 receives the water transmission/reception amount plan, the predicted water level of the distribution reservoir, and the upper and lower limit setting device 4 of the water distribution reservoir water level from the storage device 35 .
Upper and lower limits H of water level in the distribution reservoir when modifying the water transmission/reception amount plan from 5.
2. Take out L2 and revise the water transmission/reception amount plan.

For example, if a correction is made at time n, the water level in the water distribution reservoir will reach its highest level at time m')':'! ,=↓−S Izumiji Wτ;
．． ―゛””(1)ΔYi=(H2-0hm)×A/(m
-n) Let i=N,...,m-1.

At this time, the treatment capacity of the water treatment plant changes rapidly.
Species: し噌碛で(1)ζ? ? r? ? wealth? Let the amount of correction of the amount of water received by the self-water pond be Δ i.

The thus revised water transmission/reception amount plan and water distribution reservoir water level prediction value are sent to the storage device 35 to update the previous values, and the water transmission/reception amount plan is sent to the water amount command device 38. The water amount command device 38 gives a flow rate command value to the water distribution reservoir inflow amount control devices 17 to 19 at the entrance of each water distribution reservoir based on the revised new water transmission/reception amount plan.

Further, the measured values of the water level gauges 20 to 22 are periodically sent to the storage device 35, and the water distribution reservoir water level monitoring device 44 is activated. The water distribution reservoir water level monitoring device 44 stores this water level in the storage device 3.
5 and the upper and lower limits H3 of the reservoir water level set by the upper and lower limit setting device 45 for the reservoir water level.
, L3, and when the difference with the predicted water level of the distribution reservoir exceeds the allowable value or exceeds the upper and lower limits H3 and L3 of the water distribution reservoir water level, the water transmission/reception amount plan correction device 43 is activated, and thereafter the same as described above is performed. Perform the following operations.

The effects of this invention are listed below.

(1) The upper and lower limits of the water distribution reservoir water level when formulating the water transmission and reception amount plan are narrower than the upper and lower limits of the water distribution reservoir water level that determine whether or not to modify the water transmission and reception amount plan, so even if there is some error in the predicted water distribution amount, There is no need to revise the water transmission/reception volume plan.

(2) If the water level in one of the distribution reservoirs exceeds the upper and lower limits of the water distribution level and the water transmission/reception amount plan is revised, the target lower limit of the water level of the distribution reservoir after the revision is wider than the original upper and lower limits of the water level of the distribution reservoir, so other There is room to change the water volume in the distribution reservoirs, and it is easy to modify the water transmission and reception volume plan.

(3) Once the water transmission and reception amount plan is revised, the upper and lower limits of the water distribution reservoir water level, which are used to judge whether or not to revise the water transmission and reception amount plan again, are wider than the upper and lower limits of the water distribution reservoir water level after the correction, so the predicted water distribution amount Even if some errors occur, there is no need for correction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a water supply system and its operation method to which the present invention is applied, and FIG. 2 is an explanatory diagram of the upper and lower limits of the water level of a water distribution reservoir according to the present invention.

Claims (1)

[Claims] 1. In the operation method of the water distribution reservoirs that make up the water supply system, there is a process of formulating an operation plan that keeps the distribution of water in the water distribution reservoir constant for a specific period, and when the water level of the water distribution reservoir exceeds the upper and lower limits in the operation plan, A process of correcting the water amount allocation in a time zone separated by the time when the water level of the water distribution reservoir is the highest and lowest, a process of calculating the amount of correction of the amount of water received by the water distribution reservoir so that the water level of the water distribution reservoir does not exceed the upper and lower limits, and the correction described above. The step of calculating each correction amount is based on the upper limit value H_1 and the lower limit value L_1 of the water level of the distribution reservoir at the time of the operation plan, and the step of correcting the upstream flow rate based on the amount, and the step of calculating each correction amount based on Upper limit value H_2 and lower limit value L_2 of the water distribution reservoir water level, upper limit value H_3 and lower limit value L_3 of the target water distribution reservoir water level at the time of modifying the operation plan.
The value of H_1<H_2<H_3, L_1>L_2>L
A water reservoir operation method characterized by correcting the operation plan so that the water level of the water reservoir does not exceed the upper and lower limits in the relationship _3.