JPS6025754B2 - Abnormality diagnosis device for reactor water supply control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for diagnosing abnormalities in the entire reactor water supply control system in boiling water nuclear power generation equipment.

Conventional equipment for diagnosing abnormalities in water supply control systems of this type includes: ■ one that determines an abnormality based on whether or not the reactor water level is within the permissible fluctuation range; A method that detects and determines an abnormality using a trip signal, ■ Loss of control signal from the water supply control device (
There are methods to detect abnormality (scaling down) and determine abnormality.

However, since the method (2) above determines an abnormality based on the water level fluctuation, which is the final phenomenon resulting from an abnormality in the water supply control system, it has the disadvantage that early abnormality diagnosis is difficult.

In addition, with methods ■ and ■, an abnormality is only determined when a trip signal from the water supply control device is obtained or a control signal from the water supply control device is lost, respectively; It can be said that they are incompetent when it comes to occurrence. Therefore, in the case of methods ■ and ■, it is ultimately necessary to use the diagnostic method of ■, but as mentioned above, in the case of method ■, the reactor water level actually fluctuates as a result of an abnormality, and the allowable fluctuation range Normally, the plant is forced to shut down because it is not determined that there is an abnormality until after the deviation occurs. As described above, the related device has the disadvantage that it cannot quickly and accurately diagnose abnormalities in the water supply control system, which reduces the operating rate of the plant. The present invention has been made in consideration of these circumstances, and its purpose is to quickly and accurately know the occurrence of an abnormal situation in the water supply control system, and to suppress plant shutdowns to the necessary minimum. An object of the present invention is to provide an abnormality diagnosing device for a reactor water supply control system, which is capable of improving the operating rate of a plant.

Hereinafter, details of the present invention will be clarified with reference to embodiments shown in the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. 1 is a reactor pressure vessel, into which water pumped by a pump 2 of the water supply control system is fed through a water supply pipe 3. V is supplied. Steam generated by the pressure vessel 1 is sent to the turbine 5 through the main steam pipe 4. The turbine 5 rotates the generator 6 to generate electricity. The steam used in the turbine 5 is condensed in a condenser 7 and returned to the water pump 2 through a pipe 8. On the other hand, the water level of the water 9 supplied into the pressure vessel 1 is detected by the water level detector 1, and the water supply control device 11 is activated according to the detected water level signal and the water level setting signal given to the terminal TO. It operates to control the rotation of the pump motor 12.

The pump motor 12 drives the water supply pump 2 to supply a predetermined amount of water into the pressure vessel 1. In FIG. 1, reference numeral 20 shown at the bottom is an abnormality diagnosis device for diagnosing abnormalities in a water supply control system including operated equipment (actuators).

This abnormality diagnosis device 20 has first and second signals that individually diagnose the main steam flow rate signal S1 arriving at the terminal TI, the feed water flow rate signal S2 arriving at the terminal T2, and the reactor water level signal S3 arriving at the terminal T3. , third input signal diagnosis circuit 301,
302, 303, and the first and second input signal diagnostic circuits 30
a first determination circuit 40 that determines an abnormality in the water supply control system based on the difference between the signals SII and SI2 that have passed through SII and SI2;
A second determination circuit 5 compares the signal S13 that has passed through the third input signal diagnosis circuit 303 with the water level setting signal S5 that arrives at the terminal T5, and determines whether there is an abnormality in the water supply control system based on the difference.
0, and the first to third input signal diagnostic circuits 301 to 30
3 and abnormal signals S40 and S50 sent from the first and second determination circuits 40 and 50, respectively, and output this signal to the water supply control system. Terminal T6 as abnormal signal S60
It consists of a logic circuit 60 that sends out signals from the FIG. 2 is a block diagram showing the configuration of each part of the diagnostic device 20 in more detail.

First to third input signal diagnostic circuits 301, 302, 303
have exactly the same configuration. Therefore, in FIG. 2, only the configuration of the first input signal diagnosis circuit 301 is illustrated, and the second and third input signal diagnosis circuits 302 and 303 are omitted. The first input signal diagnosis circuit 301 is
The input signal arriving at terminal TI, that is, the main steam flow rate signal S
an isolation amplifier 31 that amplifies the signal I and sends the signal SII from the terminal TII, and constantly monitors whether the level of the output signal SI1 of the amplifier 31 is within a preset range;
A level determiner 32 that outputs an abnormal signal S21 when the set range is exceeded, and a level determiner 32 that constantly monitors whether the change rate of the signal SI I is below a preset rate of change and detects whether the set range is exceeded. A signal change rate determiner 33 that outputs an abnormal signal S22 when the above-mentioned determination devices 32 and 33 output an OR output of the output signals S21 and S22 is obtained, and this OR output signal, that is, an abnormal signal S31 is sent from a terminal T31. It is composed of an OR circuit 34. Note that the isolation amplifier 31 has a high input impedance, and is designed to prevent an electrical circuit failure within the diagnostic device 20 from affecting the input point of the input signal SI. Similarly, the second input signal diagnostic device 30
2 amplifies the water supply flow rate signal S2 arriving at the terminal T2 to obtain a signal S12, and sends this signal S12 from the terminal T12, and also outputs an abnormality signal S32 when the level and rate of change of the signal S12 deviates from a set range. The signal is configured to be sent out from the terminal T32.

Similarly, the third input signal diagnosis device 303 amplifies the reactor water level signal S3 arriving at the terminal T3 to obtain the signal S13,
This signal S13 is sent out from the terminal T13, and an abnormality signal S33 is sent out from the terminal T33 when the level change rate of the signal S13 deviates from a set range.

The first determination circuit 40 includes the first input signal diagnosis circuit 3
01 and the amplified feedwater flow rate signal S12 sent from the second input signal diagnosis circuit 302; Difference signal S4 from arithmetic unit 41
1 continues for a predetermined time or more and deviates from a set range, a deviation determiner 42 sends out an abnormal signal S42, and a calculator 42 predicts fluctuations in the reactor water level by, for example, performing an integral calculation on the difference signal S41. 43, a predicted water level determiner 44 that sends out an abnormal signal S44 when the predicted water level signal S43 including the water level fluctuation calculated by the calculator 43 deviates from the set range, and from each of the above-mentioned determiners 42, 44. It is comprised of an OR circuit 45 that obtains an OR output of the abnormal signal to be sent out and sends this OR output signal to the outside as an abnormal signal S40.

the second judgment circuit 5; the third input signal diagnosis circuit 3;
An adder/subtractor 51 that compares the amplified reactor water level signal SI3 sent from the terminal T5 with the water level setting signal S5 arriving at the terminal T5 to obtain a difference signal S51, and a difference signal S51 output from the adder/subtractor 51. The water level determiner 52 sends an abnormality signal S50 to the outside when the water level exceeds the set range for a predetermined period of time or more.

The details of the logic circuit 6 are as shown in FIG. 1, so no special explanation will be given here.

Since this abnormality diagnosis device is configured as described above, any one of the process signals such as the main steam flow rate signal SI, the feed water flow rate signal S2, and the reactor water level signal S3 that arrive at the terminals T1, T2, and T3 has a certain level. If there is an abnormality in the rate of change, the input signal diagnostic circuits 301, 302, 3
03, abnormal signals S31, S32, S33, etc. are sent out through the logic circuit 60 and output from the terminal T6 as the water supply control system abnormal signal S60. Therefore, for example, if an abnormality occurs in the water supply control device 11 or each device and the signals S1 and S2 become abnormal, the abnormality will be immediately detected even when the reactor water level is not abnormal. Further, if the difference signal between the main steam flow rate signal SI and the feedwater flow rate signal S2 itself is abnormal, or if the predicted reactor water level predicted from the lid signal is abnormal, the first determination circuit 40 sends out an abnormality signal S40, which is transmitted through the logic circuit 60 as a water supply control system abnormality signal S.
It is output as 60. Therefore, even if an abnormality such as a trip signal not being sent occurs in the water supply control equipment or the like and water supply control begins to be affected, the abnormality will be immediately detected. Furthermore, if the reactor water level deviates significantly from the set water level for some reason and the difference exceeds the set range, the second judgment circuit 5
An abnormal signal S50 is sent from the logic circuit 60.
The water supply control system abnormality signal S60 is outputted through the water supply control system abnormality signal S60.
Therefore, not only in the case of a failure in the pressure vessel 1 itself, but also in the case of a failure in other abnormality detection means, if an abnormality occurs in the actual reactor water level, the system will automatically detect the The occurrence of an abnormal situation will be detected. This makes it extremely reliable. Note that the present invention is not limited to the above embodiments.

For example, in the embodiment, the input signal diagnostic circuits 301 and 302
.
By utilizing the logical sum (OR) function of the logic circuit 60, the OR circuits 34 and 45 may be omitted. Further, in the embodiment described above, the logic circuit 60 is exemplified as one that obtains only a logical sum, but if necessary, part or all of the logic circuit 60 may be constituted by a logical product circuit. In other words, the logic circuit 60 may be one that generates the water supply control system abnormality signal by performing a logical operation on each input abnormality signal under required conditions. It goes without saying that various other modifications can be made without departing from the gist of the present invention. As explained above, according to the present invention, abnormalities in the water supply control system are determined and detected from multiple aspects and comprehensively based on process signals such as the Z'ri signal, the water supply flow rate signal, and the reactor water level signal. This makes it possible to quickly and accurately detect the occurrence of an abnormal situation before the reactor water level ultimately changes due to the occurrence of the situation, and to take appropriate measures at an early stage, making it necessary to shut down the plant. It is possible to provide an abnormality diagnosis device for a reactor feed water control system that can minimize abnormality and improve plant operation rate.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of the main part of the embodiment in more detail. 1... Reactor pressure vessel, 2... Water supply pump, 3... Water supply pipe, 4... Main steam pipe, 5
... Turbine, 6... Generator, 7...
... Condenser, 10 ... Water level detector, 20.
...Diagnostic device. Figure 1 Figure N Vertical

Claims (1)

[Claims] 1. Monitor the signal level and signal change rate for each of the reactor water level signal, feed water flow rate signal, and main steam flow rate signal, and detect when the signal level deviates from the set range or when the signal change rate exceeds the set range. an input signal diagnostic circuit group that sends out an abnormal signal when the signal deviates from the set range; a first determination circuit that predicts and calculates water level fluctuations and sends an abnormal signal when the water level including the predicted fluctuations deviates from a set range; and a difference between the reactor water level signal and the water level setting signal. a second determination circuit that sends out an abnormality signal when the signal deviates from a set range for a predetermined period of time or more; and each abnormality signal that is sent out from the first and second determination circuits and the input signal diagnosis circuit group, respectively. What is claimed is: 1. An abnormality diagnosis device for a nuclear reactor feed water control system, comprising: an OR circuit that performs a logical operation on and outputs a water supply control system abnormality signal. 2. Claim 1, characterized in that the first determination circuit is equipped with an arithmetic unit that integrates the difference signal between the feed water flow rate signal and the main steam flow rate signal to predict water level fluctuations in the reactor.
An abnormality diagnosis device for a nuclear reactor feed water control system as described in .