JPH0785612B2 - Power plant monitoring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power plant that determines the quality of an analog type process detector in a power plant and monitors the state of the power plant based on a detection signal from a normal detector. Regarding monitoring equipment.

[Technical background of the invention and its problems] A large number of analog type process detectors are arranged in a power plant. The process data obtained from these detectors is used for the purpose of reducing the load on operators. Introduced in a computer, comparing the limit value for each process data and displaying alarms such as those that exceed the limit value, and displaying on the variable display part of the plant system diagram according to the operator's request. It is used to monitor the power plant by performing display processing and displaying output from the typewriter device to the CRT device.

However, in this case, if the analog type process detector itself becomes abnormal, accurate process data according to the plant state at that time cannot be obtained, and the power plant cannot be monitored. In order to eliminate such a defect, it is necessary to set a limit value for detecting a defect in the detector and compare the process data obtained from the analog type process detector with this limit value to judge whether the detector is good or bad. .

As a method of judging the quality of the analog type process detector, there is a method of using the electric span of each analog type process detector as a limit value. However, this method is effective when the detector becomes completely defective, and cannot detect when the detector becomes unstable.

Therefore, in order to judge the quality of the analog type process detector including the case where the detector becomes unstable,
Conventionally, the predicted value that each detector in a certain plant state can take, that is, the value obtained from the heat balance, is used as the average value, and the upper and lower limit limits are determined by plus or minus from the average value by the operator's intuition, and the upper and lower limits. The limit value was used to determine the quality of the detector. However, in this method, if the heat balance of the plant deviates due to the secular change of the plant, the type of fuel, the operating environment (temperature), etc., the limit value for detecting the defect of the process detector has no meaning. Becomes As a result, every time the above-mentioned factors occur, messages of deviation from the limit value occur frequently, which hinders stable operation of the power plant. In order to solve this, it was necessary to set the limit value again, which was a burden on the operator.

[Object of the Invention] The present invention accurately determines the quality of a detector by accurately determining a limit value for diagnosing an analog type process detector of a power plant, and accurately monitors a plant based on accurate process data. It is an object of the present invention to provide a power plant monitoring device that enables the above.

[Summary of the Invention] The present invention collects process data for detector diagnosis in advance regarding load outputs that can be taken by a power plant in consideration of the fact that the detected value of each analog type process detector varies depending on the load output of the power plant. , The standard deviation is calculated from the collected data together with the average value for the dispersion of the detected data, and the limit value for detector diagnosis is set from this standard deviation to diagnose the quality of the analog type process detector. It is the one.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram of a power plant monitoring apparatus according to an embodiment of the present invention, in which a power plant 1 is provided with a large number of analog type and digital type process detectors. . Reference numeral 2 is an input device for sequentially scanning and inputting process data P obtained from a detector arranged in the power plant 1 and outputting it as a process variable C. 3 is an engineering unit conversion means for converting the process variable C into a process amount D of an engineering unit. Reference numeral 4 denotes an operator console, in which PF1 (detector diagnostic limit value data collection and calculation request) and PF2 are provided, as shown in FIG.
Various function keys 41, 42, 43, etc. such as (request for calculation of limit value for detector diagnosis), PF3 (start of detector diagnosis), ten keys, character keys and the like are arranged. Reference numeral 5 is a detector diagnostic limit value creating means, which is various functional blocks 51 to 55 shown in FIG.
It is equipped with. A limit value storage table 6 stores the limit values created by the detector diagnostic limit value creating means 5. 7
Is a detector malfunction detecting means, which executes processing in the procedure shown in FIG.

With the above configuration, as shown in FIG. 1, the process data P obtained from the analog type process detectors arranged in each part of the power plant 1 are sequentially taken in by the input device 2, and the engineering unit conversion means is set as the process variable C. Input to 3. These signals are converted into a process amount D in engineering units by the engineering unit converting means 3 and output to the detector diagnostic limit value creating means 5 and the detector malfunction detecting means 7.

A plant operator has an operator console 4 shown in FIG.
By operating the function key 41 of, in the detector diagnostic control value creation means 5, the process data collection SW1 shown in FIG. It is buffered in the collection buffer 51 at regular intervals for each process PID (measurement point). At this time, the collection counter 52 counts the number of data for each PID buffered in the process data collection buffer 51, and when the count value N reaches a preset limit value DC, or when the operator When the function key 42 of the operator console 4 is turned on, SW2 is turned on to output N pieces of data collected for each PID to the average value calculation means 53. This average value calculation means 53
Then, the average value of N data is calculated based on the following equation.

Here, D ₁ i is the process data indicating the i-th value when the possible values of the process data of PID No. 1 are divided into n ways, fi represents the frequency, and specifically, the i-th It means the number of processes that take a value.

The standard deviation calculation means 54 calculates the standard deviation D ₂ by the following equation based on this average value and the N pieces of process data D ₁ input from the process data collection buffer 51.

The limit value calculating means 55 calculates the standard deviation D ₂ calculated by the standard deviation calculating means 54 by a times (68% of the normal distribution when 1 times, 95% when 3 times the normal distribution).
Double the limit value to cover 99%) and calculate the upper and lower limit value D ₃ for detector failure detection.

The detector diagnostic limit value creating means 5 has the average value thus calculated by the average value calculating means 53 and the control value calculating means 55.
The limit value D ₃ calculated in step ₃ is output to the limit value storage table 6.

The limit value storage table 6 stores these values, D _3, for each process data, and limits the average value ₁ corresponding to the process data output from the engineering unit conversion means 3 and the corresponding limit value D ₃ . The value D ₄ is output to the detector failure detecting means 7.

The detector malfunction detecting means 7 starts the detector diagnosis as shown in the flowchart of FIG. 4 when the detector diagnosis start function key 43 prepared in the operator console 4 of FIG. 2 is turned on. Yes (70). First, whether the process amount D sent from the engineering unit conversion means 3 satisfies the following expression based on the detector malfunction detection limit value D ₄ and the average value ₁ sent from the limit value storage table 6. It is determined (71). ₁ + D ₄ >D> -D ₄ (3) If the above equation (3) is satisfied, the process for this process data D is terminated. On the other hand, if not satisfied, it is determined that the detector has a defect, and then the limit value deviation direction is determined, so it is determined whether or not the following expression is satisfied (72). ₁ -D _4> is satisfied D ...... (4) above (4), to set the lower limit departure flag "L _1" (73). On the other hand, if satisfied, sets the upper limit value departure flag "U _1" (74). Then, how much the process amount D deviates from the average value ₁ is the actual deviation H.
= D- ₁ is calculated (75). Finally, the actual deviation H
And the upper limit deviation flag U ₁ or the lower limit deviation flag L ₁ create a defect message and end the processing (76).

As shown in FIG. 5, this defect message is composed of an input point number 83, an abnormal message 84, an abnormal direction 85, and an abnormal amount 86. Of these, the input point number 83 is added to the process amount D and input from the engineering unit conversion means 3. Abnormal message
84 uses message data stored in the detector malfunction detecting means 7. For the abnormal direction 85, the direction is determined by the upper limit deviation flag U ₁ and the lower limit deviation flag L ₁ , and a symbol indicating the direction such as an arrow is added. The actual deviation H is added as it is to the abnormal amount 86.

The output device 8 sends these trouble messages to the CRT device 81.
Alternatively, it is output from the typewriter device 82 in the format shown in FIG.

In this way, by introducing an automated device that uses a computer, it becomes possible to collect data for each operation under various specified loads and set the limiting conditions according to each situation. The heat balance data is taken as an average value, and the setting of the limit value that relies on the operator's intuition to take the plus or minus several% of the average value can be automated by computer processing, and the plant that greatly affects the heat balance of the plant Even if there is a change in conditions,
The limit value can be set immediately, and the detector abnormality detection corresponding to the plant condition can be constantly and accurately performed. As a result, the process data from the plant can be constantly improved in reliability and notified to the operator, and it is possible to prevent a mistrip and a decrease in efficiency due to a defect in the detector. In addition, the plant operator can know the degree of malfunction of the detector by issuing a message such as the abnormal direction of the abnormality detector and the amount of abnormality. After that, the degree of reliability of the input data from the abnormality detector can be checked. Very useful to know.

It should be noted that a part of the processing of the detector diagnostic limit value creating means 5 shown in FIG. 3 is modified and, as shown in FIG. 6, an important plant condition change determination processing 50 is performed instead of the process data collection SW1.
May be provided to automatically calculate the limit value when there is a change in an important condition (fuel switching, etc.) in heat balance of the plant.

Further, by partially modifying the processing of the detector diagnostic limit value creating means 5 shown in FIG. 3, the limit value calculating means 55 is replaced by the limit value calculating means (1) 56 and the limit value as shown in FIG. Calculation means (2)
The first limit value D ₅ and the second limit value D ₆ may be created under the condition of two times and three times the standard deviation. In this case, the processing of the detection failure detecting means partially modifies the block shown in FIG. 4, and as shown in FIG. 8, the two limit values of the first limit value D ₅ and the second limit value D ₆ ( An error message is judged by judging the degree of deviation of the process amount D from D ₆ <D ₅ ).
You can change the 84 output characters.

That is, in FIG. 8, when the detector diagnosis is started, it is determined whether the following formula is satisfied using the first limit value D ₅ (71A). ₁ + D ₅ >D> ₁ −D ₅ (5) If satisfied, end normally. If not satisfied, the second limit value D ₆ is used to determine whether the following expression (6) is satisfied (71B). ₁ + D ₆ >D> ₁ −D ₆ (6) If the above formula is satisfied, a message of sensor failure is created as a deviation from the first limit value D ₅ (76A), and
If it is not satisfied, a sensor failure message is created as a deviation from the second limit value (76B), and the message is displayed and output on the output device 8 to set two levels that call attention to the operator. To do.

[Advantages of the Invention] As described above, according to the present invention, it becomes possible to accurately know the defect of the process detector, and it is possible to prevent the mis-strip of the power plant due to the defect of the detector. . In addition, by introducing an automated device using a computer, it is possible to collect data for each operation under various specified loads and set the limiting conditions according to each situation, so that the malfunction of the process detector can be promptly performed. It is possible to detect, and the failure time of the detector can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block configuration diagram of a detector diagnostic device portion in a power plant monitoring device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of an operator console in FIG. 1, and FIG. The figure is a functional block diagram of the detector diagnostic limit value creating means of FIG.
FIG. 4 is a flow chart of the processing of the detection failure detection means of FIG.
FIGS. 5 (a) and 5 (b) are explanatory views of the output device of FIG. 1, FIGS. 6 and 7 are functional block diagrams showing another embodiment of FIG. 3, and FIG. 8 is FIG. 10 is a flow chart of processing showing another embodiment of FIG. 1 ... Power plant, 2 ... Input device, 3 ... Engineering unit conversion means, 4 ... Operator console, 5 ... Detector diagnostic limit value creation means, 6 ... Limit value storage table, 7
…… Detector failure detection means, 8 …… Input device.

Claims (1)

[Claims] 1. A power plant monitoring apparatus for processing process data obtained from detectors arranged in various parts of the power plant, creating data necessary for monitoring the power plant, and displaying and outputting the data on an output device. In certain specified operating conditions, the process data is collected, the average value is calculated, the standard deviation is calculated from the average value and the collected data, and the standard deviation is multiplied by the specified value to create the limit value. Limit value creating means, a limit value saving table for saving the created limit value together with the average value, and whether the limit value range deviates from the average value of the process data obtained during operation of the power plant It is characterized in that it is provided with a detector failure detecting means for judging whether or not there is a defect, and an output device for displaying and outputting data regarding the detector in which the failure is detected. A power plant monitoring device to collect.