JPS5935043B2 - Water volume smoothing system for water distribution facilities - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to water supply and distribution facilities for waterworks, and in particular to a received water amount smoothing system that uses the storage capacity of the received water amount to smooth out the received water amount in response to fluctuations in demand. 10.

Conventionally, in water supply and distribution facilities, as shown in Figure 1, when distributing the water stored in the receiving volume 1 to the demand end 3 using the distribution pump 2, a pump was installed downstream of the distribution pump 2. The demand flow rate transmitter 4 measures the demand amount by 15, sends a signal indicating this demand amount to the water distribution pump operation control device 5,
Pump operation is controlled in proportion to demand.

On the other hand, the amount of water received for the amount of water received 1 is determined by a water receiving flow rate transmitter 6 installed in the water receiving pipe line to the water receiving amount 1, a control valve T installed between this flow rate transmitter 6 and the water receiving amount 201, It is controlled as follows using the water receiving amount water level gauge 8 installed at the receiving water amount 1. The first method is to increase or decrease the amount of water received using the control valve T in proportion to the water level of the amount 1 of water received. As shown in FIG. 1, the second method is to systematically change the target value of the water level of the water level controller 9 according to the demand pattern using the program setting device 10. The flow rate target value of the receiving water flow rate controller 11 obtained from the signal indicating the water level from the total 8 is given to the receiving water flow rate controller 11. Receiving water flow rate controller 3
011 determines the opening adjustment signal of the control valve T from the target flow rate value and the signal indicating the received water flow rate from the received water flow meter transmitter 6, and adjusts the opening degree of the control valve T to adjust the received water flow rate. Control to target value. In other words, by varying the received water level over time according to the demand pattern 35, the amount of water received is somehow smoothed out. In FIG. 1, reference numeral 12 indicates a water reservoir in a remote location, and 13 indicates a water pump that supplies water from the water reservoir 12. However, the second point in controlling the amount of water received as described above is
In this method, the amount of demand fluctuates seasonally and daily, and there is a difference between the value set as the demand amount pattern and the actual amount of demand, and the deviation between the target water level of the water reservoir and the actual water level of the water reservoir occurs. As the amount of water increases, the target value of water intake also fluctuates.
Since smoothing the amount of water received is actually difficult, there is a problem in that the target value of the water level of the water receiving pond must be changed frequently in response to the amount of demand.

An object of the present invention is to provide a system for smoothing the amount of water received by a water distribution facility that can solve the above-mentioned problems.

Therefore, in the present invention, an appropriate fixed time t is determined based on the current demand, the water level of the water receiving pond, and the amount of water received, and the water level of the water receiving pond after the time t is calculated if the current state is continued for the time t. to find the predicted water level. On the other hand, the water level takes a zero or small value within the operating range determined based on the critical water level of the receiving pond, and the absolute value increases rapidly when the upper or lower limit of the operating range is exceeded. A relationship curve between the received water amount correction rate α and the water receiving pond water level, which has a positive sign on the lower side and a negative sign on the higher side with the center water level of the operation region as the boundary, is stored in the memory device. Then, find the value of the received water amount correction rate α corresponding to the predicted water level, calculate the correction value Q (1 + α) of the current received water amount Q, and use this Q (1 + α) as the target of the received water flow rate controller. The intended purpose was achieved by feeding this value to the controller and using the control valve to control the amount of water received to the target value. Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a system diagram showing an embodiment of the system for smoothing the amount of water received at a water distribution facility according to the present invention. Note that the same parts as in FIG. 1 are given the same reference numerals, and explanations thereof will be omitted. In FIG. 2, reference numeral 21 denotes a received water amount smoothing calculation device, which receives a signal Q1 indicating the demand amount from the demand flow transmitter 4, a signal L indicating the water level from the water receiving pond water level gauge 8, and a receiving water flow rate transmitter 6. A signal Q indicating the amount of water received is input. Further, a signal Q1 indicating the demand amount from the demand flow rate transmitter 4 is input to the water distribution pump operation control device 5, and the operation control of the water distribution pump 2 is performed in proportion to this demand amount Q1. A signal Q indicating the amount of water received from the water flow rate transmitter 6 is inputted to a water flow rate controller 11 that controls the opening degree of the control valve 7 . The received water amount smoothing calculation device 21 uses the current demand amount Q1, the water receiving pond water level L, and the received water amount Q,
The predicted water level L' of the water receiving pond 1 after time t when the current state is continued for a predetermined period of time t is calculated using the following equation.

L'=-{L+(Q-Q1)t} ・・・・・・・・・
...(1) K1 1 where K: Constant determined by the shape of the water reservoir On the other hand, apart from the above, the operating range of the water level of the water reservoir 1 is determined based on the dangerous water level of the water reservoir 1, and this Within the operating region, the water level is constant zero as shown in Figure 3a, or zero at the center of the operating region as shown in Figure 3b, and the lower limit water level LWL
The absolute value gradually increases with a positive sign toward
The absolute value gradually increases with a negative sign toward the upper limit water level HWL, and when it exceeds the upper or lower limit water level of the operating range, it increases linearly as shown in Figure 3a or in Figure 3b.
A relationship curve between the received water amount correction rate α and the water level of the water receiving pond, which has the characteristic that the absolute value increases rapidly through the curved portion as shown in FIG. I'll keep it.

The received water amount smoothing calculation device 21 calculates the received water amount correction rate α corresponding to the previously obtained predicted water level L' of the water receiving pond 1 after time t from the relational curve stored in the memory device, and Calculate the correction value Q(1+α) of the amount of water received Q, and calculate this Q(
1+α) is given to the receiving water flow rate controller 11 as the target value of the receiving water flow rate controller 11.

The receiving water flow rate controller 11 compares this target value Q(1+α) with the signal indicating the current flow rate from the receiving water flow rate transmitter 6, and sends an adjustment signal according to the deviation to the control valve 7. 7 to control the amount of water received so that it matches the target value. According to the received water amount smoothing system of one embodiment of the present invention configured as described above, the following advantages can be obtained compared to the conventional system.

1. Calculate the predicted water level of the receiving pond after a certain period of time based on the current demand, the current water level of the receiving pond, and the current amount of water received. As long as there is no need to change the target value frequently, as the water intake amount correction rate that determines the target value of water intake amount is set to zero or a small value, the amount of water received will be adjusted as long as there are no large changes in demand. Smoothed.

In other words, in conventional systems, the target water level of the water receiving pond is changed over time in response to the pattern of demand, and the amount of water received is adjusted to follow this target water level, so naturally the amount of water received changes over time. fluctuations will increase. On the other hand, in the system according to the present invention, the capacity of the water receiving pond is fully utilized to realize smoothing of the amount of water received. (2) Since the amount of water received is smoothed, it becomes possible for the side sending water to this water distribution facility to send almost constant water, which reduces the frequency of changing the operating conditions of the water pump, which reduces the length of equipment. Contributes to stable operation over a period of time.

In the above-described embodiment, the relationship curve between the water level of the water receiving pond and the correction rate of water received is stored in the memory device, but the correction rate may be obtained by a function generator.

In addition, the relationship curve between the water level of the water reservoir and the correction rate of water intake is not limited to the one illustrated in Figure 3 a and b, but various patterns can be prepared depending on the conditions such as the capacity of the water reservoir and the amount of demand. You can use the one that is most suitable for the conditions of the water distribution facility and the season. In addition to the balance of water at water distribution facilities, we also consider other liquids, gases (controlled based on the relationship between air supply/distribution amount and tank internal pressure), and powders (storage hoppers and demand/supply amounts). It can also be applied to smoothing the volume balance centered on storage facilities, such as in the case of As described in detail above, according to the present invention, it is possible to provide a smoothing system for a water distribution facility that can realize smoothing of the amount of water received as a result of fully utilizing the capacity of the water receiving pond of the water distribution facility.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional example of water reception amount control at a water distribution facility; Fig. 2 is a system diagram showing an example of a system for smoothing the amount of water received at a water distribution facility according to the present invention; and Fig. 3 A and b are graphs showing different patterns of the relationship curves between the water receiving pond water level and the water receiving amount correction rate used in the system shown in FIG. 2, respectively. 1... Water receiving pond, 2... Water distribution pump, 3
... Demand end, 4 ... Demand flow transmitter,
5...Water pump operation control device, 6...
・Water receiving flow rate transmitter, 7... Control valve, 8...
...Receiving pond water level gauge, 11...Receiving water flow rate controller,
12... Water reservoir, 13... Water pump, 21... Received water amount smoothing calculation device.

Claims (1)

[Claims] 1. In a water reception and distribution facility where water sent by a water pump from a separate water transmission pond is stored in a water reception pond and water is sent to the demand end by a water distribution pump, the water level in the reception pond is measured from the water level gauge installed in the water reception pond. A signal L indicating the amount of water received and a signal Q indicating the amount of water received from the receiving water flow rate transmitter installed in the flow path to this water receiving pond.
Using the signal Q_1 indicating the demand amount from the demand flow transmitter installed downstream of the water distribution pump, the predicted water level L' of the water receiving pond after t time when the current situation continues for the time t is calculated as L'=
1/K{L+(Q-Q_1)t}, and using this predicted water level L' of the receiving pond, the center water level within the operating range of the receiving pond water level set in advance in the built-in memory device or function generator. The absolute value gradually increases with a positive sign toward the lower limit water level, and the absolute value gradually increases with a negative sign toward the upper limit water level, or it becomes a constant value of zero within the above region and the operating region The received water amount correction rate α is determined from the relationship curve between the received water amount correction rate α and the water level of the receiving pond, which has the characteristic that the absolute value increases rapidly when the above values are exceeded, and the received water amount Q is corrected using this received water amount correction rate α. A received water amount smoothing calculation device that calculates a value Q (1 + α) and provides it as a target value to a received water flow rate controller that adjusts the opening degree of a control valve installed between the received water flow rate transmitter and the receiving pond. A system for smoothing the amount of water received at a water distribution facility.