JP3599755B2 - Flow rate abnormality detection device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a device for detecting an abnormality in an operation state of a boiler, a cooling tower, or the like, and particularly to a flow rate abnormality detection device for detecting an abnormality in a flow rate of makeup water or the like.
[0002]
[Prior art]
In the operation management of the boiler, cooling tower, etc., sensors are provided at various facilities on the site, and when detecting an abnormality in the operation state based on the measurement value output by the sensor, the measurement value output by the sensor and the set value are used. In comparison, a method of detecting an abnormality based on the magnitude relationship between these values is employed. Also, if an alarm is output immediately after judging an abnormal condition based on the comparison result, the alarm may occur frequently due to the instability of the measurement signal. A procedure that emits is also considered.
[0003]
[Problems to be solved by the invention]
However, for example, when a site worker refills the cooling tower with cooling water, if the replenishment water valve is manually opened and forgotten to be closed as it is, the replenishment water amount measured within a unit time becomes equal to the set value. If an abnormal state occurs in which the measurement does not exceed and the measurement continues for a long time, the abnormal state cannot be detected by the method of detecting the abnormality based on the magnitude relationship between the measured value and the set value. For this reason, make-up water is continuously injected into the cooling tower, which not only wastes water, but also injects more than necessary make-up water, thereby diluting the supplied water treatment chemicals and reducing its effect. The problem occurs.
[0004]
The present invention has been made in view of the above points, and has as its object to provide a flow rate abnormality detection device that detects a flow rate abnormality that is not detected from a measurement value measured within a unit time. .
[0005]
[Means for Solving the Problems]
According to the present invention to achieve the above object, according to the present invention, there is provided a flow rate abnormality detection device used for operation management when injecting by supplying a make-up water to a boiler or a cooling tower by manually opening a make-up water valve. A flow sensor that measures the amount of water flow per unit, an input signal processing circuit that processes and outputs information of the flow sensor into appropriate flow data per time, and a memory that stores the flow data for a certain past time, Compare the flow rate data output from the input signal processing circuit with a preset flow rate abnormality detection value, and when the result is not a flow rate abnormality, calculate a flow duration time from the flow rate data stored in the memory. A determination circuit for detecting an abnormality by comparing the injection duration set as an abnormality detection condition is provided.
[0006]
[Action]
When supplying make-up water to the boiler or cooling tower by manually opening the make-up water valve and injecting make-up water continuously for a fixed amount over a long period of time, the measured value of the flow sensor is substantially constant. Become. This measured value is processed into appropriate flow rate data per time by the input signal processing circuit, and sent to the judgment circuit and the memory. The judgment circuit compares the input flow rate data with a preset flow rate abnormality detection value, and calculates the flow duration time from the flow rate data stored in the memory to detect the abnormality even if the result is not a flow rate abnormality. An abnormality in the flow rate is detected by comparing with the injection duration set as a condition. Thereby, even when the flow rate data is lower than the flow rate abnormality detection value and the flow rate value itself is not abnormal, it is possible to detect a phenomenon that the manner of continuing the flow rate is abnormal.
[0007]
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
In FIG. 1, a flow sensor 1 is provided in a water injection pipe for supplying cooling water to a cooling tower, generates a signal corresponding to a flow rate per unit time, and transmits the signal to an input signal processing circuit 2. The input signal processing circuit 2 processes the signal input from the flow rate sensor 1 into a proper flow rate per hour, outputs the processed flow rate data as corresponding flow rate data, and adds the data to the memory 3 and the determination circuit 4. The flow sensor 1 may output a signal per unit flow rate.
[0008]
The memory 3 stores the flow rate data input from the input signal processing circuit 2 and outputs the flow rate data specified according to a request from the determination circuit 4 to the determination circuit 4. The determination circuit 4 sets the current situation based on the current flow rate data input from the input signal processing circuit 2 and the past flow rate data read out from the memory 3, and the current condition matches the abnormality detection condition. It judges whether or not, and if it matches, outputs an alarm signal to the outside.
[0009]
The abnormality detection condition is set based on the water flow rate and the injection continuation time, for example, an integrated value of the water flow rate within a specific time, the continuation of a certain time of the water flow with a specific range, and the like. The abnormality detection condition may be set in the judgment circuit 4 or may be stored in the memory 3, or an abnormality detection condition holding circuit may be provided separately from the judgment circuit 4 and the memory 3. The judgment circuit 4 may be called from the abnormality detection condition holding circuit if necessary.
[0010]
The operation will be described below.
For example, suppose that the worker forgets to close the makeup water valve after opening the makeup water valve and injecting makeup water into the cooling tower. As a result, make-up water will be substantially constant amount over a long period of time from time t ₀ to close the supply water valve of Figure 2 is continuously injected. When the makeup water valve is fully opened, the quantity of makeup water passing through the makeup water valve is lower than the flow rate abnormality detection value set for abnormality detection as shown in FIG. The flow rate sensor 1 outputs substantially the same measured value and supplies the same to the input signal processing circuit 2 because a fixed amount of make-up water is continuously injected. The input signal processing circuit 2 processes the input measured value into flow rate data per unit time required by the judgment circuit 4, adds the data to the judgment circuit 4, and stores the data in the memory 3.
[0011]
The determination circuit 4 compares the data of the makeup water flow rate input from the input signal processing circuit 2 with the flow rate abnormality detection value. However, since the amount of makeup water is lower than the flow rate abnormality detection value, the determination circuit 4 determines that it is normal. Next, decision circuit 4, the memory 3 stored in and past a certain period of passing water data reads a time t ₀ from time t ₁ to the replenishment water is to supplied The times continuous (makeup water Abnormal continuation time). When the calculated make-up water abnormality duration exceeds the injection duration set as the abnormality detection condition, the determination circuit 4 determines that the water supply state is abnormal and outputs an alarm signal. Therefore, it is possible to cope with an abnormality in the amount of make-up water by this alarm signal.
[0012]
It should be noted that the flow rate of the water within a specific range may be added to the condition, instead of simply looking at the make-up water injection continuation time. It may be.
[0013]
【The invention's effect】
As described above, according to the present invention, it is possible to detect an abnormal flow rate of water in a water treatment system, and to detect forgetting to close a water supply valve due to an operation error or the like. There is an effect that safer operation of the system becomes possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a flow rate abnormality detection device according to the present invention.
FIG. 2 is a graph showing a relationship between an abnormal water flow rate in the water treatment system and its continuation time.
[Explanation of symbols]
1 Flow rate sensor 2 Input signal processing circuit 3 Memory 4 Judgment circuit

Claims (1)

A flow rate abnormality detection device used for operation management when injecting by supplying a make-up water to a boiler or a cooling tower by manually opening a make-up water valve ,
A flow rate sensor for measuring the flow rate per unit time, an input signal processing circuit for processing information of the flow rate sensor into appropriate flow rate data per time and outputting the same, and a memory for storing the flow rate data for a fixed time in the past And, comparing the flow rate data output from the input signal processing circuit with a preset flow rate abnormality detection value, and when the result is not a flow rate abnormality, calculates a flow duration time from the flow rate data stored in the memory. And a determination circuit for detecting an abnormality by comparing with an injection duration set as an abnormality detection condition.

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