JPH05165531A - Water distribution controller - Google Patents

Abstract

PURPOSE:To normally operate even when the device is abnormal by discriminating it from the transition of changes in the measuring signals of a received water flow meter, water level gauge and distributed water flow meter whether the measuring signals of remaining meters are true or not. CONSTITUTION:For example, when a water level gauge 2 is made abnormal and a fixed value is outputted, a water level is decreased or increased when there is difference in the respective measured values of a distributed water flow meter 3 and a received water flow meter 5. When a water level signal 7 keeps a fixed value, however, a sensor error judging part 12 judges the truth of the water level signal 7, namely, the error of the water level gauge 2 from the transition of changes in respective measuring signals 9 and 8 of the received water flow meter 5 and the distributed water flow meter 3. In the case of error, an arithmetic unit 6 stops the function of an automatic control system using the water level signal 7 and controls a received water flow value so that distributed water flow and received water flow can be equal by the distributed water flow signal 8 and the received water flow signal 9. Then, irreducibly minimum control can be executed so as not to generate the water supply suspension of a distributing water pool 1 and overflow. Thus, even when the device is abnormal, the normal operation is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water distribution control device having a sensor abnormality detection function in a water plant.

[0002]

2. Description of the Related Art There are signals such as water level, flow rate, pressure, etc., which are important measurement items in a water supply plant. At the entrance of a water purification plant, an intake well that receives the taken-in water and a filter pond that filters the water. In addition to the above, there are many ponds such as clean water reservoirs, pump wells, and distribution reservoirs, which have important meanings such as the flow rate connected to each, the pressure for flowing, and each is related to automatic control. There is.

For example, the water level in a distribution reservoir is particularly important, and if water runs out, it will lead to water interruption, causing confusion in social life, and if it overflows, it will drain water and waste resources.

Taking the water level signal as an example, the measured signal is 4
If the signal is 4 mA DC or less, or 20 mA DC or more if it is up to 20 mA DC, it will fall outside the sensor measurement range, and the anomaly can be detected and treated as a sensor anomaly. Also, the case where the signal itself is cut off due to a cable break or the like can be detected in the same manner as above.

That is, it is possible to notify the details of the abnormality by detecting the abnormality, stop the automatic control, and switch the operation to the manual control.

[0006]

Here, there are other abnormal patterns of water level gauge other than 4 mA DC or less, 20 mA DC or more, and cable breakage.

In an abnormal state within 4 to 20 mA DC, that is, when the sensor itself holds in the normal measurement pattern, a constant value signal is output regardless of whether the actual water level is present or not. There is a level, but it is an abnormality that looks like a state.

When such an abnormal state occurs, the conventional technique cannot judge the abnormality, and the automatic control is continued for the water level signal having a constant value which is an abnormal value, and the distribution flow rate is higher than the receiving flow rate. If there are many, the actual water level will drop and the water will be cut off. On the contrary, if the distribution flow rate is low and the receiving flow rate is high, the actual water level will rise and overflow the pond.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a receiving flow meter which measures the flow rate of receiving water flowing into a reservoir by a pump and outputs a receiving flow rate signal, and a water level which measures the water level in the reservoir. Transition of change in measured signal of water level meter that outputs signal, distribution flow meter that measures flow rate of distribution water flowing out from distribution reservoir and outputs distribution flow rate signal, and these reception flow meter, water level meter, distribution flow meter To a sensor abnormality determination unit that determines whether the measurement signals of the remaining meters are true or false, and is a water distribution control device.

[0010]

In the sensor abnormality detecting device according to the present invention, the flow rate of the receiving water flowing into the reservoir is measured by the pump to output the receiving flow rate signal, and the water level of the reservoir is measured to output the water level signal. , The flow rate of distribution water flowing out from the distribution reservoir is measured, the distribution flow rate signal is output, and the abnormal signal that is input and retained is predicted by comparing it with other measurement conditions inside the plant, and the validity of the abnormal signal is verified. A water level control signal is output based on the determination result from the sensor abnormality determination unit, the received water flow rate signal, the water level signal, and the distribution water flow rate signal, and the pump operation is controlled by the water level control signal.

[0011]

EXAMPLE An example of the present invention will be described below. In FIG. 1, reference numeral 5 is a water flow meter that measures the flow rate of the water received by the pump 4 into the reservoir 1 and outputs a water flow signal 9. Reference numeral 2 is a water level gauge that measures the water level of the distribution reservoir 1 and outputs a water level signal 7. Reference numeral 3 is a distribution flow meter which measures the flow rate of the distribution water flowing out from the distribution reservoir 1 and outputs a distribution flow rate signal 8. Reference numeral 12 is a sensor abnormality determination unit that determines the validity of the abnormal signal by predicting by comparing the input and held abnormal signal with other measurement states inside the plant. Reference numeral 11 denotes a water level control unit that outputs a water level control signal from the determination result from the sensor abnormality determination unit 12, the received water flow rate signal 9, the water level signal 7, and the distribution flow rate signal 8. A pump operation control unit 10 controls the operation of the pump 4 by a water level control signal. In a water plant, a sensor that measures water level, pressure, flow rate, etc., holds an anomaly that has been held at a value within the measurement range. An abnormality detection device for a sensor, which has an abnormality determination circuit that predicts and compares a predicted abnormality with a detected value to detect a sensor abnormality, and has a function of stabilizing a control target without using a signal of the sensor determined to be abnormal.

That is, normally the water level is automatically controlled by the signal from the water level meter itself, but the basic function as a reservoir is recognized as a plant, and the first-order delay based on the input and output elements is used. By monitoring the water level with elements, the flow rate of the incoming water that is the input to the reservoir (in this figure, it is a flow meter, but it can be replaced by the flow rate), the operating state of the water pump, etc. Based on the relationship between the flow rate value and operation pattern and the value of the distribution flow rate, which is the output from the distribution reservoir, it is determined whether the distribution reservoir water level will rise or fall, and whether the signal of the current water level gauge is moving. Check to see if the water level gauge is abnormal.

In order to keep the water level in the reservoir 1 constant, the water level control unit 11 is provided with a water level gauge 2 and the water level signal 17 measures the water level to determine the difference from the target value. In order to prevent this from occurring, a command is issued to the pump operation control unit 10 based on the distribution flow rate value and the received water flow rate value, and the pump 4
The water level of the distribution reservoir 1 is controlled by operating and stopping.

Here, if the water level gauge 2 becomes abnormal within the measurement span of 4 to 20 mA DC and a constant value is output, the received water flow rate value measured by the distribution water flow meter 3 and the received water flow meter 5 are measured. If there is a difference between distribution flow rate> acceptance flow rate in the flow rate value, the water level should drop. On the contrary, the distribution flow rate <
If there is a difference in the received flow rate, it should rise.

Nevertheless, the water level signal 7 remains at a constant value, and when there is no change in the water level signal 7 even after the passage of time, a water level gauge abnormality is judged.

Since the water level signal 7 is not normal after the water level meter abnormality is determined, the automatic control system using the water level signal 7 is stopped and the water flow rate signal 8 measured by the water flow meter 3 is measured. And the received water flow rate signal 9 measured by the received water flow meter 5
The water flow rate is controlled so that the water flow rate and the water flow rate are the same. Then, it is possible to execute the minimum control so that the water in the distribution reservoir 1 will be cut off so that the water will not run out or the overflow will overflow.

[0017]

According to the present invention, steady operation is possible even when an abnormality occurs in the device, and reliability is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a water distribution control device showing an embodiment of the present invention.

[Explanation of symbols]

 11 ... Water level control unit 12 ... Sensor abnormality determination unit

Claims (1)

[Claims] 1. A receiving flow meter for measuring a flow rate of receiving water flowing into a reservoir by a pump and outputting a receiving flow signal,
A water level meter that measures the water level of the distribution reservoir and outputs a water level signal, a distribution flow meter that measures the flow rate of the distribution water flowing out from the distribution reservoir and outputs a distribution flow rate signal, and these receiving flow meters,
A water distribution control device comprising: a sensor abnormality determination unit that determines the authenticity of the measurement signals of the remaining meters based on the transition of changes in the measurement signals of the water level meter and the water flow meter.