JPH08246510A - Distributing basin water level control system - Google Patents

Abstract

PURPOSE: To stably supply city water even if the water level of a distributing basin cannot be directly monitored by detecting water feed pressure in a water feed pipe for a source to be converted into a water level and controlling a feed water pump in accordance with the water level. CONSTITUTION: A distributing basin water level meter 4 transmits an analog current signal corresponding to the change of the water level of a distributing basin 3 to a water feed source system 2 via a telemeter transmitter 5 and a communication line 7. A controller 12 receives a detected signal from the telemeter receiver 11 and controls the water level in accordance with pressure detected by a water feed pressure gauge 15 when the water level of the distributing basin is abnormal. Then, a feed water pump 17 is stopped, static water feed pressure is detected in the state that a discharge valve 18 is closed and the water level of the distributing basin is computed from a prescribed expression. The controller 12 performs zero point adjustment to obtain this computed results and range adjustment to obtain signals similar to those from the distributing basin water level meter 4. When a difference from the water level is below a specified value, the feed water pump 17 is operated at the stage that the water level signal becomes a low water level LWL after the range of the water feed pressure meter 15 is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level control system for a distribution reservoir, which monitors the water level of a distribution reservoir located at a distance and controls the water level of the distribution reservoir by a water pump on the monitoring side.

[0002]

2. Description of the Related Art In a supervisory control facility scattered over a wide area such as a water supply plant, a water level signal of each reservoir is transmitted to a supervisory control facility via a telemeter device of a monitored station, and a water pump on the monitoring side is used. It was common to control the water level in each distribution reservoir.

[0003]

However, in the water level control system as described above, when any one of the abnormalities such as the failure of the water level gauge, the failure of the telemeter device, the failure of the data communication line and the power failure accident occurs, The water level cannot be monitored. In that case, operators need to go to the site, measure the water level with a measure, etc., and manually operate the pump by wireless communication with a monitoring station. When such a situation occurs, there is a problem that the supply of tap water becomes unstable.

The present invention has been made to solve the above problems, and even if direct monitoring of the water level of a distribution reservoir becomes impossible, it is possible to stably supply tap water to consumers. The purpose is to provide a control system.

[0005]

A water level control system for a distribution reservoir according to claim 1 detects the water level of a distribution reservoir at a remote place connected by a water distribution pipe, and transmits the water so as to keep the detected water level within an allowable range. In controlling the original water supply pump, a water supply pressure gauge for detecting the water supply pressure of the water supply pipe of the water supply source and converting the detected pressure into a water level is provided, and the water supply pump is controlled based on the converted water level.

The water level control system for a distribution reservoir according to a second aspect of the present invention is, as a transmission pressure gauge, a zero suppression means for converting a detected pressure into a water head and converting this head to a water level from the bottom of the distribution reservoir, and the converted water level. And a range changing means for changing the range to a practical range are used.

According to a third aspect of the present invention, there is provided a water level control system for a water reservoir, wherein a water level gauge for directly detecting the water level of the water reservoir and a water pressure for detecting a water pressure of a water pipe of a water source and converting the detected pressure into a water level. It is equipped with a pressure gauge and a means for judging whether the output of the reservoir water level gauge is normal or abnormal.When the output of the reservoir water level gauge is normal, the water pump is operated based on the detected water level of this reservoir water level gauge. When the output of the reservoir water level gauge is abnormal, the water pump is controlled based on the water level converted by the water pressure gauge.

According to another aspect of the present invention, there is provided a water level control system for a water reservoir, which compares the water level detected by the water level gauge of the water reservoir with the water level converted by the water pressure gauge while the water supply pump is stopped, and outputs the output of the water pressure gauge. A means for checking is provided.

The water level control system for a reservoir according to claim 5 is, as a transmission pressure gauge, a zero suppression means for converting a detected pressure into a head and converting this head into a water level from the bottom of the reservoir, and the converted water level. And a range changing means for changing the range to a practical range are used.

In the distribution reservoir water level control system according to claim 6, in controlling the water pump based on the water level converted by the water pressure gauge, the upper water level is determined based on the difference between the lower limit water level and the upper limit water level within the allowable range. And a means for calculating the operating time of the water pump until reaching the water supply pump, and the water pump is operated for the calculated operating time.

[0011]

In the distribution reservoir water level control system according to claim 1, the fact that the transmission pressure of the transmission source connected by the transmission pipe depends on the water level of the distribution reservoir is used. Since it was converted and the water pump was controlled based on the water level, the water level meter that directly detects the water level, the telemeter that transmits the detected value, the power supply equipment, etc. failed, and direct monitoring of the water level of the distribution reservoir was possible. Even if it becomes impossible, tap water can be stably supplied to customers.

In the distribution reservoir water level control system according to the second aspect, the water level from the bottom of the distribution reservoir is determined based on the detected pressure, and the range is changed to a practical range.
There is an advantage that it can be handled exactly like the signal obtained by directly detecting the water level.

In the distribution reservoir water level control system according to the third aspect, while directly detecting the water level of the distribution reservoir, the water level is indirectly detected based on the water supply pressure of the water supply pipe at the water supply source and directly detected. When the detected water level is normal, the water pump is controlled based on that water level, and when it is abnormal, the water pump is controlled based on the indirectly detected water level. Even if it becomes impossible, tap water can be stably supplied to customers.

In the water level control system for a distribution reservoir according to a fourth aspect, the indirect water level detection value is checked using the directly detected water level detection value while the water supply pump is stopped. The accuracy of detection can be improved, and stable supply to customers can be further ensured.

In the water level control system of the reservoir according to the fifth aspect, the water level from the bottom of the reservoir is determined based on the detected pressure, and the range is changed to a practical range.
There is an advantage that it can be handled exactly like the signal obtained by directly detecting the water level.

In the water level control system for a reservoir according to claim 6, the operating time of the water pump from the lower limit water level to the upper water level is calculated, and the water pump is operated only during this operating time. Since it is not necessary to stop the water pump on the way to detect the hydrostatic pressure, the water level can be smoothly controlled.

[0017]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In this embodiment, a reservoir system 1 and a water source system 2 are connected by a water pipe 6 and a communication line (NTT dedicated line) 7. Of these, the reservoir system 1 includes a reservoir water level gauge 4 and a telemeter transmitter 5.
It has. The reservoir water level gauge 4 detects the water level of the reservoir 3 and adds an analog signal to the telemeter transmitter 5. The telemeter transmitter 5 converts the analog signal of the reservoir water gauge 4 into a digital signal, and a communication line. 7 is used to send the water to the water source system 2.

The water source system 2 is a control LAN.
Telemeter receiver 11 connected to (LOCAL AREA NETWORK) 21, controller 12 using a DCS (DIGTAL CONTROL STATION), and man-machine interface 20
It has. The telemeter receiver 11 receives a water level signal sent from the communication line 7 and sends it to the control LAN 21. Controller 12 is a process I / O bus
It is connected to the process input / output control unit 14 by 13. Then, the controller 12 performs the setting operation of the water pressure gauge 15 for detecting the pressure of the water source via the process input / output control device 14, while taking in the detection signal, the water reservoir 19
Capture of detection signal of water level gauge 22 for detecting water level of
Also, the water level signal from the telemeter receiver 11 is taken in through the control LAN 21 to supply the water pump 17 and the discharge valve.
It controls the 18. Further, the man-machine interface 20 has a CRT itself, and monitors the control state.
Also, it is possible to give priority to the control of the controller 12.

Here, the water pressure gauge 15 and the controller 12
Is the well-known HART (Highway Addressable Remort Tra
nsducer) Smart transmission based on the specifications, the water pressure gauge 15 converts the water pressure into a current signal, and at the same time, a zero suppress function and measurement to change the zero point setting by the input digital signal. It has a range change function to change the range. In addition, the external cable 16 connecting the input / output control device 14 and the water pressure gauge 15 is
Although it is a normal CVVS two-wire cable, the same cable is used to supply operating power from the input / output controller 14 to the water pressure gauge 15, and to detect and transmit the pressure and water level by superimposing a digital signal on the analog signal. It enables remote setting of various parameters such as measurement range.

The operation of this embodiment configured as described above will be described below with reference to FIGS. 2 to 5. This reservoir water level control system uses a high water level HWL (HIGH WATER L) which is the upper limit of the allowable range of water level fluctuations in the reservoir 3.
EVEL) and water level low level LWL which is the lower limit of the allowable range
(LOW WATER LEVEL) is set, and when the detected water level becomes the water level low level LWL, the water pump 17 is operated to supply water to the distribution reservoir 3, and when the detected water level becomes the water level high level HWL, the water pump 17 is stopped and water supply is stopped.

Therefore, the water level meter 4 of the distribution reservoir detects the water level of the distribution reservoir 3 and changes from the direct current of 4 mA to 20 m according to the change of the water level.
An analog current signal varying up to A is applied to the telemeter transmitter 5. The telemeter transmitter 5 converts the analog signal into a digital signal and transmits it to the telemeter receiver 11 which constitutes the water source system 2 via the communication line 7.
The controller 12 is a central control device of the water source system 2, receives a detection signal of the water level of the reservoir from the telemeter receiver 11, and determines whether this is normal or not. Then, if normal, when the water level falls to the low water level LWL, the water pump 17 is operated and the discharge valve 18 is opened.
Water is sent to the distribution site 3 via the water supply pipe 6, and when the water level rises to the high water level HWL, the water supply pump 17 is stopped and the discharge valve 18 is closed to stop the water supply to the distribution site 3. On the other hand, when the detection signal of the water level of the reservoir from the telemeter receiver 11 is abnormal, the same water level control as described above is performed based on the detected pressure of the water pressure gauge 15.

When the water level of the water reservoir is controlled based on the pressure detected by the water pressure gauge 15, the level of the bottom of the water reservoir 3 compared to the water source of the water pipe 6 is H as shown in FIG. 2 (a). Is only high. Therefore, the water pressure gauge 15 is shown in FIG.
As shown on the left vertical axis in (b), the sum of the head pressure corresponding to the level difference H and the water pressure corresponding to the water level of the distribution reservoir 3 is detected as the static water supply pressure Ps. In order to convert this static pressure feed pressure Ps into the water level L of the distribution reservoir, it is necessary to subtract the hydrohead pressure Ph corresponding to the distance H as shown on the right vertical axis of (b). Since the static pressure water supply pressure Ps cannot be detected during the operation of the water supply pump 17, the controller 12 detects the static pressure water supply pressure Ps when the water supply pump 17 is stopped and the discharge valve 18 is closed. The water level L of the reservoir is calculated by the following formula. Reservoir water level L = static pressure feed pressure Ps-head pressure Ph (1) In this case, the controller 12 is the process input / output controller 14
By controlling the supply of operating power to the water pressure gauge 15, and zero point adjustment to obtain the calculation result of the above formula (1),
That is, zero suppression and further range adjustment for obtaining a signal similar to that of the reservoir water level gauge 4 are performed.

When the water level of the distribution reservoir is controlled on the basis of the water level detected by the water pressure gauge 15, the controller 12 also monitors the water level of the water reservoir 20 (reception tank or water purification tank) to protect the water pump. Is. Also, the controller 12
It is also possible to monitor the control state of the above by the man-machine interface 20 equipped with a CRT, or to manually control the controller 12 with priority.

When the water level of the reservoir is controlled based on the water level detected by the water pressure gauge 15, the controller 12 controls the water level data detected by the water level gauge 4 and the water level of the water pressure gauge 15 adjusted to zero. It is compared with the data and it is checked whether the difference exceeds a preset specified value. If the difference exceeds a specified value, it also has a function of issuing an alarm.

When the water level difference is less than the specified value, the controller 12 operates the water pump 17 when the water level signal after the range change of the water pressure gauge 15 becomes the low water level LWL. Since the static pressure water supply pressure Ps cannot be detected, the required flow rate required to raise the water level from the low water level LWL to the high water level HWL is obtained at that time,
Further, the operation time of the water supply pump 17 up to the high water level HWL is calculated by dividing by the pump water supply capacity per hour. The calculation formula at this time is as follows.

[0026]

[Equation 1] Among the various functions of the controller 12 described above, the specific processing procedure of the main functions will be described below. FIG.
Is a flow chart of initial adjustment when using the water pressure gauge 15 as a reservoir water level gauge. In step 101, the initial value ST
When an ART request is input, it is determined in step 102 whether the water pump is stopped. If stopped, in step 103, the water pressure static pressure value Ps is determined by the HART protocol procedure.
Then, in step 104, the water level value L of the reservoir which has been used so far is read. Next, in step 105, the water level value L of the distribution reservoir is subtracted from the static pressure value Ps of the water supply pressure to obtain the head pressure Ph, which is stored in step 106. next,
In step 107, the zero transition parameter is transmitted to the water pressure gauge according to the HART protocol procedure according to the head pressure Ph
Further, in step 108, a range change signal for setting the same range as that of the distribution pond water level meter is transmitted, and in step 109, the mode is changed to the distribution pond water level meter mode. The head pressure Ph can be manually set using the man-machine interface 20.

FIG. 4 is a flow chart for carrying out a comparative diagnosis for using the water pressure gauge 15 as a water level gauge for water distribution.
Water level comparison START in step 111 at the specified fixed cycle
Takes. Then, in step 112, the water level gauge 4 for comparison is diagnosed, and if normal, wait until the water supply pump is stopped in step 113. If the water supply pump is stopped, in step 114 it is determined whether the water pressure gauge mode is selected. Check whether. If the water pressure gauge 15 is not in water level mode,
In step 115, the zero shift by Ph is performed by the above-mentioned HART protocol procedure, and in step 116, the water level range of the reservoir is set and the water level mode is set. Next, in step 117 the source water level data is read, in step 118 the reservoir water level data is read, in step 119 the reservoir water level data is subtracted from the source water level data, and in step 120
In step 121, the absolute value is converted, and in step 121, the water level difference given by the absolute value is compared with the specified value.

FIG. 5 is a flow chart for automatically controlling the water level of the reservoir using the detected value of the water pressure gauge 15 when the water level signal of the reservoir is abnormal. Here, first, in step 131, the abnormality of the water level gauge 4 of the reservoir is detected, and in step 132, the abnormality of the telemeter transmitter / receiver is detected, and the logical sum is calculated in step 133. If this OR signal is significant, the water level detection signal from the water level gauge 4 is abnormal, so the water pump is stopped in step 134. Next, in step 135, the parameters for water pressure detection are transmitted to the water pressure gauge, and in step 136 the water pressure gauge 15 is switched to the reservoir water level gauge mode.

Next, it is judged whether or not the water level value of the distribution reservoir switched in step 137 has dropped to the low water level LWL,
If it decreases, the required flow rate required to raise the water level from the low water level LWL to the high water level HWL is obtained in step 138, and is further divided by the pump water pump capacity per hour according to the above equation (2), The operating time of the water pump 17 up to the water level HWL is calculated. Then step
In 139, the water pump 17 is operated, and then in Step 140, it is judged whether or not the above operating time has elapsed.When that operating time has elapsed, the water pump is stopped in the next Step 141, and the water level becomes low. It is in a standby state until reaching the water level LWL.

Thus, it is necessary to calculate the operation time of the water supply pump and continue the operation of the water supply pump 17 until the time comes, thereby stopping the pump for taking in the water level detection signal. Since there is no property, there is an advantage that smooth control can be performed.

When the water level of the reservoir and the telemeter transmitter / receiver are restored in the middle of the water level control using the water pump, the water pump is kept in the current state and the water pressure gauge 15 is in the original water pressure mode. Then, the control target is switched from the transmission pressure gauge 15 to the distribution reservoir water level gauge 4, and the distribution reservoir water level control is continued.

In the above embodiment, the water level signal detected by the water level gauge 4 of the reservoir is converted into a digital signal according to the protocol specified in RS234, using the telemeter transmitter 5 and the telemeter receiver 11. Alternatively, an A / D converter may be provided between the reservoir water level gauge 4 and the control LAN 21, and the controller 12 may be configured to take in its output signal.

[0033]

As is apparent from the above description, according to the water level control system of the distribution reservoir according to the first aspect, the detected water supply pressure is converted into the water level, and the water supply pump is controlled based on the water level. As a result, even if the water level meter that directly detects the water level, the telemeter that transmits the detected value, the power supply equipment, etc. malfunction and direct monitoring of the water level of the distribution reservoir becomes impossible, tap water can be stabilized to the customers. Can be supplied to the customer.

According to the water level control system of the distribution reservoir according to the second aspect, the water level from the bottom of the distribution reservoir is determined and converted into a practical range. Therefore, it is obtained by directly detecting the water level. It can be treated exactly like a signal.

According to the water level control system of the distribution reservoir according to the third aspect, when the detected value of the directly detected water level is normal, the water supply pump is controlled based on the water level, and indirectly when it is abnormal. Since the water supply pump is controlled based on the detected water level, tap water can be stably supplied to the customer even if direct detection of the water level becomes impossible.

According to the distribution water level control system of the fourth aspect, since the indirect water level detection value is checked using the directly detected water level detection value, the accuracy of the indirect water level detection is improved. Therefore, it is possible to further secure a stable supply to customers.

According to the water level control system of the distribution reservoir according to the fifth aspect, since the water level is converted into a practical range, there is an advantage that the signal obtained by directly detecting the water level can be treated in exactly the same way.

According to the water level control system of the distribution reservoir according to the sixth aspect, the operating time of the water pump from the lower limit water level to the upper limit water level of the allowable range is calculated, and the water feed pump is operated only during this operating time. Therefore, it is not necessary to stop the water pump on the way to detect the hydrostatic pressure, and there is an effect that the water level can be smoothly controlled.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the embodiment shown in FIG.

FIG. 3 is a flow chart for explaining the operation of the embodiment shown in FIG.
The flowchart which shows the specific processing procedure of a main component.

FIG. 4 is a flow chart for explaining the operation of the embodiment shown in FIG.
The flowchart which shows the specific processing procedure of a main component.

5 is a diagram for explaining the operation of the embodiment shown in FIG.
The flowchart which shows the specific processing procedure of a main component.

[Explanation of code] 1 water reservoir system 2 water source system 3 water reservoir 4 water reservoir water level gauge 5 telemeter transmitter 6 water supply pipe 7 communication line 11 telemeter receiver 12 controller 13 process input / output bus 14 process input / output control device 15 water supply Pressure gauge 16 External cable 17 Water pump 18 Discharge valve 19 Water reservoir 20 Man-machine interface 21 Control LAN

Claims (6)

[Claims] 1. A distribution reservoir water level control system for detecting a water level in a distribution reservoir at a remote place connected by a water supply pipe and controlling a water supply source pump so as to keep the detected water level within an allowable range. A water level control system for a reservoir, comprising a water pressure gauge for detecting a water pressure of a water supply pipe and converting the detected pressure into a water level, and controlling the water supply pump based on the converted water level. 2. The water pressure gauge converts the detected pressure into a water head and converts the water head into a water level from the bottom of the reservoir, and a range for changing the converted water level into a practical range. The reservoir water level control system according to claim 1, further comprising: a changing unit. 3. A water level control system for a water level control system, which detects a water level of a water level distribution reservoir connected by a water supply pipe and controls a water supply source water pump so as to maintain the detected water level within an allowable range. Water level gauge that directly detects the water level of the water, a water pressure gauge that detects the water pressure of the water pipe of the water source and converts the detected pressure to the water level, and determines whether the output of the water level gauge is normal or abnormal. When the output of the reservoir water level gauge is normal, the water supply pump is controlled based on the detected water level of the reservoir water level gauge, and the output of the reservoir water level gauge is abnormal. At this time, the water level control system for the reservoir, wherein the water pump is controlled based on the water level converted by the water pressure gauge. 4. A means for comparing the water level detected by the water level gauge with the water level converted by the water pressure gauge to check the output of the water pressure gauge while the water supply pump is stopped. The reservoir water level control system according to claim 3, wherein 5. The water supply pressure gauge converts the detected pressure into a water head, converts the water head into a water level from the bottom of the reservoir, and a range for changing the converted water level into a practical range. The reservoir water level control system according to claim 4, further comprising: a changing unit. 6. When controlling the water feed pump based on the water level converted by the water feed pressure gauge, the water feed pump of the water pump until reaching the upper limit water level based on the difference between the lower limit water level and the upper limit water level in an allowable range. The water level control system for a reservoir according to any one of claims 3 to 5, further comprising: means for calculating an operation time, wherein the water supply pump is operated only during the calculated operation time.