JP2774031B2 - Method and apparatus for controlling water level in distribution reservoir - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a water level in a reservoir in a water supply system, and more particularly, to controlling a valve provided in a pipe on an inflow side of a reservoir in accordance with an upstream pressure. This controls the water level in the reservoir.

[0002]

2. Description of the Related Art Conventionally, in a pipeline network such as a water supply system, a plurality of branch pipes are laid from a main pipe to each distribution zone, and a distribution reservoir or a storage tank is provided in the middle of the main pipe system. The increase or decrease in the amount of water used in each distribution zone is addressed by increasing or decreasing the amount of water stored in the reservoir or storage tank.

[0003] For this reason, it is necessary to secure an appropriate water level in the reservoir. Conventionally, a change in the water level of the reservoir is regarded as an object to be directly controlled, and is provided in an inflow pipe connected to the reservoir. The valve opening is controlled based on the water level.

[0004]

However, in the above-mentioned conventional configuration, the opening of the valve is operated only in response to a change in the water level of the reservoir, and the water level is set when the water level of the reservoir decreases. Since the priority is given to returning to the water level, the valve opening becomes too large and the pressure in the pipeline upstream of the distribution reservoir drops, and sufficient water distribution to the upstream distribution zone cannot be performed. There is a problem that the water pressure and the water volume in are insufficient.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a method and apparatus for controlling a water level of a reservoir, which can appropriately maintain the water level of the reservoir in consideration of the pressure upstream of the reservoir. The purpose is to provide.

[0006]

In order to solve the above-mentioned problems, a method for controlling the water level of a reservoir according to the present invention comprises the steps of: determining in advance the pressure in an upstream pipe communicating with the reservoir via a flow control valve; The relationship between the appropriate inflow rate to the reservoir under the pressure required to maintain the pressure at or above the allowable lower limit is determined, and when the water level detected by the water level gauge falls below the set value in the reservoir, the upstream The pressure in the side pipe is detected by a pressure gauge, an appropriate inflow rate corresponding to the detected pressure value is calculated based on the above relationship, and further, an opening degree in the flow control valve necessary to obtain an appropriate inflow rate is calculated. By operating the flow control valve so that the calculated opening degree is obtained, an appropriate inflow flow rate is supplied to the distribution reservoir to return the water level to the set value.

[0007] A water level control device for a distribution reservoir according to the present invention includes a flow control valve comprising a variable porosity orifice valve disposed in the middle of an upstream pipeline communicating with the distribution reservoir, and a flow control valve located upstream of the flow control valve. Pressure gauge installed in the upstream pipeline, a differential pressure gauge that measures the pressure difference between the upstream and downstream sides of the flow control valve, an opening gauge that measures the opening of the flow control valve, and the water level of the reservoir. And a controller that controls the flow rate control valve based on each measurement value of the pressure gauge, the differential pressure gauge, the opening gauge, and the water level gauge, and the controller includes the differential pressure gauge A flow rate operation circuit for calculating the current inflow flow rate in the flow rate control valve based on the differential pressure value measured in step (a) and the opening degree measured by the opening degree meter, and a pressure value measured by the pressure gauge based on a function input in advance. Is the input pressure A set flow rate calculating circuit for calculating an appropriate inflow flow rate into the lower reservoir, and comparing the appropriate inflow rate calculated by the set flow rate calculation circuit with the current inflow rate calculated by the flow rate calculation circuit to adjust the current inflow rate appropriately. An opening calculation circuit for calculating an opening required to match the inflow flow rate;
Opening / closing control for operating the flow control valve so that the opening of the flow control valve is adjusted to the opening calculated by the opening arithmetic circuit while the water level of the reservoir measured by the water level gauge is equal to or lower than the set water level. And a circuit.

[0008]

According to the above-mentioned method of the present invention, the flow in the upstream pipe is distributed from the upstream pipe by setting the inflow rate flowing into the reservoir through the flow control valve to the above-mentioned appropriate inflow rate. The water level of the reservoir can be maintained at an appropriate level while maintaining the level above the allowable lower limit that does not affect the ward.

With the device of the present invention, when a multi-porous orifice valve is used as a flow control valve, the flow rate can be calculated from the differential pressure across the valve and the opening of the valve. For this reason, the current flow rate of the current flowing into the reservoir is determined by the flow rate calculation circuit from the differential pressure measured by the differential pressure gauge and the opening of the flow control valve measured by the opening meter.

On the other hand, the pressure in the upstream pipeline is
The relationship between this pressure and the appropriate inflow rate into the reservoir under the pressure required to maintain the pressure at or above the permissible lower limit value that does not affect the distribution area to which water is distributed from the upstream pipeline is input to the set flow rate calculation circuit as a function. In addition, an appropriate inflow flow rate into the reservoir corresponding to the current pressure of the upstream pipeline measured by the pressure gauge is calculated by the set flow rate calculation circuit.

Then, the appropriate inflow flow rate is compared with the current inflow flow rate to calculate an opening required for making the current inflow flow rate equal to the appropriate inflow flow rate by an opening calculation circuit, and the opening / closing control circuit opens the flow control valve. Operate to the right. Therefore, the calculated degree of opening does not become unnecessarily large, and the flow rate into the distribution reservoir can be controlled without causing a decrease in pressure enough to affect water distribution in the upstream distribution zone. . At this time, the flow control valve opens only when the water level of the reservoir measured by the water level gauge is lower than the set water level,
The set water level is a certain range between the upper water level and the lower water level, and the flow control valve closes at the upper water level and opens at the lower water level.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a flow control valve 3 composed of a perforated variable orifice valve is interposed in the middle of an upstream pipe line 2 communicating with a distribution reservoir 1, and a pressure gauge 4 is located upstream of the flow control valve 3. It is interposed. Further, a differential pressure gauge 5 for measuring a pressure difference between an upstream side and a downstream side of the flow control valve 3 is provided in the upstream pipe line 2, and an opening gauge 6 for measuring an opening degree of the valve body is provided in the flow control valve 3. The reservoir 1 is provided with a water level gauge 7 for measuring the water level.

A dedicated controller 8 for controlling the flow control valve 3 based on the measured values of the pressure gauge 4, differential pressure gauge 5, opening gauge 6 and water level gauge 7 is provided. The dedicated controller 8 includes a flow rate calculation circuit 9 for calculating the current inflow flow rate in the flow rate control valve 3 based on the differential pressure value measured by the differential pressure gauge 5 and the opening degree measured by the opening degree gauge 6, and a preset input. A set flow rate operation circuit 10 for calculating an appropriate inflow flow rate into the reservoir 1 under the pressure using the pressure value measured by the pressure gauge 4 as an input value based on the function thus obtained, and an appropriate inflow flow rate calculated by the set flow rate operation circuit 10. An opening calculation circuit 11 for comparing the current inflow flow rate calculated by the flow rate calculation circuit 9 to calculate an opening required to make the current inflow flow rate equal to the appropriate inflow flow rate, and a water level of the reservoir 1 measured by the water level gauge 7. An opening / closing control circuit 12 for opening the flow control valve 3 on condition that the value is equal to or lower than the set water level and operating the flow control valve 3 so as to have the opening calculated by the opening calculation circuit 11 is provided. .

The function input to the set flow rate calculation circuit 10 is as follows:
The pressure in the upstream pipe 2 and the water reservoir 1 under the pressure required to maintain the pressure at or above the permissible lower limit that does not affect the water distribution section 2a that distributes water from the upstream pipe 2.
It shows the relationship with the appropriate inflow flow rate into the tank and is obtained in advance by empirical rules and calculations. Reservoir 1
Is a certain range of water levels between the upper and lower water levels.

The operation of the above configuration will be described below.
The multi-porous variable orifice valve of the flow control valve 3 can calculate the flow rate from the differential pressure before and after the valve and the opening of the valve, so the differential pressure measured by the differential pressure gauge 5 and the flow control valve 3 measured by the opening meter 6 The current flow rate of the current flowing into the reservoir 1 is obtained by the flow rate calculation circuit 9 from the opening degree of the water supply.

On the other hand, an appropriate inflow flow rate into the reservoir 1 corresponding to the current pressure of the upstream pipeline 2 measured by the pressure gauge 4 is calculated by the set flow rate calculation circuit 10. Then, by comparing the proper inflow flow rate with the current inflow flow rate, the opening degree required for making the current inflow flow rate equal to the proper inflow flow rate is calculated by the opening degree operation circuit 11, and the opening / closing control circuit 12 opens the flow control valve 3. Operate to the right. At this time, the water level of the reservoir 1 measured by the water level gauge 7 is in a certain range between the upper limit water level and the lower limit water level, the flow control valve 3 is closed at the upper limit water level,
Open at lower water level.

Accordingly, by setting the inflow flow rate flowing into the reservoir 1 through the flow control valve 3 to the above-mentioned appropriate inflow flow rate, the pressure in the upstream water distribution section 2a is not reduced enough to affect the water distribution. In addition, the water level of the reservoir 1 can be stably maintained at an appropriate set water level while maintaining the water level at or above the allowable lower limit.

[0018]

As described above, according to the present invention, the opening degree of the flow control valve is controlled in consideration of the pressure of the upstream pipeline, and the inflow flow rate flowing into the distribution reservoir is set to an appropriate inflow flow rate. Thereby, it is possible to stably maintain the water level of the distribution reservoir at an appropriate set water level while maintaining the pressure of the upstream pipeline at or above an allowable lower limit that does not affect the upstream water distribution section.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a water level control device of a reservoir in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reservoir 2 Upstream line 3 Flow control valve 4 Pressure gauge 5 Differential pressure gauge 6 Openness meter 7 Water level gauge 8 Dedicated controller 9 Flow rate operation circuit 10 Set flow rate operation circuit 11 Opening degree operation circuit 12 Opening / closing control circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E03B 1/00 G05D 7/06 G05D 9/12

Claims (2)

(57) [Claims] 1. A pressure in an upstream pipe communicating with a reservoir via a flow control valve in advance, and an appropriate inflow rate to the reservoir under the pressure required to maintain the pressure at or above a permissible lower limit. When the water level detected by the water level gauge in the distribution reservoir drops below the set value, the pressure in the upstream pipeline is detected by the pressure gauge,
Calculate the appropriate inflow flow rate corresponding to the detected pressure value based on the above relationship, further calculate the opening of the flow control valve necessary to obtain the appropriate inflow flow rate, and set the flow control valve so that the calculated opening degree is obtained. And supplying a proper inflow rate to the distribution reservoir to return the water level to a set value. 2. A flow control valve comprising a variable porosity orifice valve interposed in the middle of an upstream pipe communicating with a distribution reservoir, and an upstream pipe located at an upstream side of the flow control valve. A pressure gauge, a differential pressure gauge that measures the pressure difference between the upstream side and the downstream side of the flow control valve, an opening meter that measures the opening of the flow control valve, a water level meter that measures the water level of the reservoir, and the pressure. A controller for controlling the flow rate control valve based on each measurement value of the pressure gauge, the differential pressure gauge, the opening meter, and the water level gauge, wherein the controller includes a differential pressure value measured by the differential pressure gauge and the controller. A flow rate calculation circuit for calculating the current inflow flow rate in the flow rate control valve based on the opening measured by the pressure gauge; and a flow rate control circuit under the pressure as a pressure value measured by the pressure gauge based on a function set in advance. Appropriate inflow to water pond A set flow rate calculation circuit for calculating the flow rate, and an open flow required for matching the current flow rate with the appropriate flow rate by comparing the appropriate flow rate calculated by the set flow rate calculation circuit with the current flow rate calculated by the flow rate calculation circuit. The degree-of-opening calculation circuit calculates the degree, and the flow control valve is opened under the condition that the water level value of the reservoir measured by the water level gauge is equal to or lower than the set water level, and the degree of opening is calculated by the degree-of-opening calculation circuit. A water level control device for a distribution reservoir provided with an opening and closing control circuit for operating a flow control valve as described above.