JPS5932820A - Loose parts monitoring method - Google Patents

Abstract

PURPOSE:To make the detecting accuracy of loose parts high and to make it possible to record the waveforms when abnormality occurs, by performing filtering by which only a specified frequency band among the vibrating sounds detected by sensors is passed. CONSTITUTION:Sounds are detected by sensors 1-10. The difference between ordinary background noises and impact sounds is discriminated by loose parts detector 11-20, which are connected to the sensors, respectively. When the presence of the impact sound is detected, the alarm signal for the occurrence of the loose parts is issued. Meanwhile, the level difference is not always clear. Therefore, the background noise level is reduced by utilizing a frequency filter, and the difference between the level and the impact sound is made clear. Based on said filtering, the detecting accuracy of the impact sound in the loose parts detectors 11-20 is enhanced. When the alarm signal is issued from the loose part detectors 11-20, said alarm signal is inputted to a loose parts locator 21, and the true or false of the alarm is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for monitoring loose parts, and more particularly to a method for monitoring loose parts that can record waveforms before and after the occurrence of a report and that can reduce false alarms.

Several methods have been proposed to date to detect the occurrence of fallen parts (loose parts) by detecting the sounds and vibrations caused by falling parts that occur inside nuclear reactors and various plants. However, it has the following drawbacks and improvements are desired.

(1) Loose parts discovery is performed by detecting kneading when there is a sudden impact sound compared to the noise (usually background noise) generated by the operation of the equipment that is to discover loose parts. However, when the banok ground noise is loud, it is difficult to distinguish it from the impact sound, making it difficult to monitor loose shoes. In particular, it becomes difficult to monitor the falling off of small parts with a small impact level.

(2) If the detection volume level is lowered to monitor even those with a small impact level, the difference from normal background noise will become increasingly brighter, causing false alarms to occur.

(3) Since the detection of loose parts is performed in a time-series manner, it is not possible to record the waveform when an abnormality occurs, making it difficult to analyze the cause after the fact.

As mentioned above, the conventional methods have various problems, and improvement thereof is desired.

An object of the present invention is to provide a loose bar monitoring method that eliminates the above-mentioned problems, has high accuracy in finding loose barbs, and can also record waveforms when an abnormality occurs.

In short, this invention performs filtering to bus only a specific frequency band of vibration sounds detected by a sensor to improve the accuracy of finding loose parts. This system recognizes the generation pattern of S alarms and distinguishes them from electrical noise, etc., thereby increasing accuracy and preventing the occurrence of false S alarms. , Furthermore, this detection result 4. I
If there is one Jit and it is determined that loose barts have occurred,
・This is the Jj method configured to record the waveform of fnbact1i.

Examples of the present invention will be described below.

In FIG. 1, reference numerals 1 to 10 indicate sensors C attached to a cleavage device for monitoring the nuclear reactor section, which detect an impact t'7 (impact sound) caused by the occurrence of Rusburtz. The sound detected by each of the sensors 1 to 0 is detected by a loose bartz day detector 11 to 220 connected to each sensor 1 to 220, respectively, to distinguish the difference between the background noise and the impact sound, and detect the presence of the impact sound. If it is detected, it will send a message indicating that loose barts have occurred.

That is, in the loose bar detectors 11 to 20, when a sound at a level of -1- above a certain value is detected with respect to normal bank ground noise, an impact sound is determined to have been generated and an alarm signal is issued. However, as mentioned above, this level difference is not necessarily clear, so a frequency filter is used to reduce the bank ground noise level and make the difference from the impact sound clear.

By using a frequency range of 1 to 5KH2, which is highly sensitive to metal impact sounds, as the filter setting value, the level of the bank ground noise B is usually lowered to make the difference from the impact I clear. With this filtering, the loose bart detectors 11 to 20
The accuracy of impact sound detection in this method is higher than that of conventional methods.

Next, when the 6J loose parts detectors 11 to 20 issue an official gazette, this alarm signal is input to the loose parts locator 21, which further judges whether the alarm is correct or incorrect.

The loose bart locator 21 stores a pattern of sound generation caused by the occurrence of loose barts, and compares it with the generation pattern of the alarm signal emitted from the loose bart detector to determine whether this signal is correct or incorrect. In other words, a loose bart detector may generate an erroneous signal due to electrical noise, etc., but if the time interval of the signal manually input to the loose bart detector does not match the pattern of occurrence of the belief associated with the occurrence of loose barts, Reset this signal. Specifically, if the second signal is manually input within a short time of 50m5 after the first signal is input, and if the third signal is manually input within Sms, the above Depending on the arrangement of the sensors 1 to 10, it is determined that the signal generation pattern is incorrect and the alarm is reset.

If the loose bar locator 21 determines that the alarm signal is positive, the renal alarm device 25 is activated to issue an alarm. On the other hand, if the data storage device is activated after determining that the official gazette signal is positive, only data after the occurrence of loose parts can be recorded. For this reason, in the data storage device 22, the analog signals from the loose,
For example: - Holds data for 1 second. As a result, if Ruth Hearts Lokake 21 determines that the signal is positive, the data
A stop signal was activated at 22nd Street. l・
At time 1-, the data storage device 122 is holding up to the signal from 1 second ago, and after 1- is stopped, sampling is performed for another 2 seconds. As a result, data for 2 seconds before the stop signal was manually applied and 2 seconds after the stop signal, that is, 2 seconds before and after the impact sound was generated, is stored. This data is further transmitted to alarm generation 11 [Q to 4 = f Dannel data recorder 23
(analog) and or 10 Novy Disc 24 (
The waveforms that led to the publication of the official gazette can be analyzed later.

By implementing this invention, since filtering is performed in a predetermined frequency band, the impact t'1 can be easily detected and the official gazette can be issued correctly.In addition, this kidney alert generation pattern can be recognized and the iE error of the gazette can be made. Since the judgment is made, the accuracy of the kidney report can be greatly improved.

Since the waveforms before and after the alarm can be recorded, the waveforms can be analyzed after the fact and can be used as data for improving the performance of the device.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an OLS detection device showing an example of the method σ according to the present invention, and FIG. 21A is a diagram showing the relationship between the spectral level and frequency of background noise and impact sound. 1 to 10...Sensors 11 to 20...Loose bart detector 21...Loose bart locator 22...Data storage device 23...4 channel data recorder 24...Floppy disk

Claims (1)

[Claims] 1. In the method of detecting the generation of loose parts by detecting the impact sound. 3. In the method of detecting the generation of loose parts, a loose parts expected generation pattern is recognized and these five reports are judged to be correct or incorrect, and if the alarm is correct. is a loose bart monitoring method characterized by recording waveforms before and after the occurrence of a report. 2. Analyze the sound detected by the sensor and analyze it with the T-detector, then manually input the signal to the loose parts locator using the iK detection, and use this loose parts locator to recognize the pattern of the occurrence of the official gazette. 2. The loose parts monitoring method according to claim 1, wherein a determination is made as to whether the warning is correct or not, and based on this determination, the warning signal is set or the waveform is recorded for a predetermined period of time before and after the official gazette is issued. 3. In the loose bart detector, use a frequency filter to reduce the hack ground noise level.
3. The loose bart monitoring method according to claim 2, characterized in that impact sounds are better identified.