JPS63193061A - Method for judging abnormality of vibration sound - Google Patents

Abstract

PURPOSE:To easily detect the abnormality of a structure, by striking an object to be inspected by a standard impact device to measure the vibration and sound of the object to be inspected by a vibration sensor and a sound sensor and comparing the same with measured data at a healthy time. CONSTITUTION:A gas-water separator 7 is mounted on the shroud head 6 of a BWR plant and placed in a water pool 4. Further, a vibration sensor 1A and a standard impact device 2A are provided to the shroud head 6. A vibration sensor 1C and a standard impact device 2C are provided to the gas-water separator 7 and a vibration sensor 1B is provided to a stand pipe 8. A sound sensor 3 is provided to the wall surface of a pool 5 and the shroud head 6 is stuck by the standard impact devices 2A, 2C to measure the vibration and sound of the shroud head 6 by the vibration sensors 1A, 1B, 1C and the sound sensor 3. The measuring signals are analyzed by a vibration analyzer 13 and a sound analyzer 11 to be compared with the signals at a soundness time by a comparator 14 to evaluate a flaw. Since the shroud head is struck under a definite condition and the wave forms of the vibration and sound thereof are analyzed, the abnormality of an object to be inspected can be easily judged.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a vibroacoustic abnormality determination method for nondestructively inspecting abnormal conditions such as deformation, loosening, cracking, and missing parts of equipment and parts, and in particular, to underwater inspection of BWR reactor internals. This invention relates to a vibroacoustic abnormality determination method suitable for. [Prior Art] Inventions related to abnormality inspection of BWR reactor internals include a grid plate inspection device that uses a tJT sensor to detect defects in a grid plate (Japanese Patent Application Laid-Open No. 61-66162).6 However, this Since it is a dedicated device, it cannot be applied to other structures, and there was no consideration given to its versatility. It is expected that However, this method cannot be applied to narrow spaces where the camera cannot approach.

[Problem that the invention attempts to solve]

Periodic inspections are performed on RWR plants every predetermined operating period, and at that time, the internal structure of the reactor is also visually inspected for defects such as cracks and scratches using an underwater television or the like. However, because the structure of the steam dryer and steam separator on the shroud head is complex, only a limited surface can be inspected using the visual method using underwater television, and it is impossible to inspect the inside of the structure, let alone the hidden areas. It is impossible to test. An object of the present invention is to provide a method for determining abnormalities in major reactor internals from the vibration and acoustic responses of the equipment to percussion. [Means for solving the problem] To determine abnormalities, including vibrations and sounds of the equipment when it is abnormal and when it is normal, the difference from the normal response is determined.
That is, this is achieved by determining the deviation response. This method has been practiced for a long time, as seen in, for example, doctors' chest percussion or auscultation of locomotive axles. The present invention differs from these in that it is measured using a measurement system that measures the hitting conditions and measurement conditions under constant conditions, and that the obtained deviation response is objective. By evaluating the measurement results, it has become possible to objectively judge the continued use of a single device. That is, to generate vibration and sound, a certain part of the equipment is struck with a standard impact tool, and the vibration and sound response of the certain part of the equipment or the acoustic response at a position a certain distance away from the equipment is measured, Compare them with the normal response using a comparator to find the deviation response.
By evaluating this with a signal evaluator, the aforementioned objective is achieved. [Operation] The above-mentioned standard impact device is capable of controlling impact energy and impact speed. Therefore, unless there is something wrong with one device,
It exhibits a reproducible and always constant vibration and acoustic response to the impact of this standard percussion device. Conversely, if there is a difference in these responses, it indicates an abnormality. A vibration sensor and an acoustic sensor that measure this vibration and acoustic response are provided at a fixed point on the device or at a fixed point away from the device. This is an abnormality determination. This fixed point measurement is an important point. The measured signal is compared with the previous signal by a comparator, and if there is a difference, it is considered as a deviation response, and an abnormality is evaluated by a signal evaluator. A judgment is made. The signal evaluator stores the normal vibration and acoustic responses of the equipment, past abnormal responses, and simulated abnormal responses, and by comparing the signals with these, it is possible to determine the presence or absence of an abnormality and its degree. A function is provided to determine the [Example] Fig. 1 shows an example of the present invention, a shroud head 6 of a BWR plant and a steam/water separator 7 mounted thereon.
is placed on a positioning stage 9 in a pool 5 containing water 4 for reasons of radial speed. The steam separator 7 is connected to the shroud 6 via a standpipe 8. The shroud head 6 has vibration sensors IA, IA'...
and a standard impact device 2A, the stand pipe 8 is provided with vibration sensors 1B, IB'..., and the air/water separator 7 is provided with vibration sensors IC, IC'... and the standard impact device 2.
G, 2G'... are provided. These vibration sensors are guided and input to the vibration amplifier 12. Acoustic sensors 3゜3' are placed at certain positions on the wall of the pool 5.
* is provided, and its signal is input to the acoustic amplifier 10. The vibration signal amplified in step 12 is subjected to a displacement or acceleration waveform, amplitude, frequency, amplitude energy, amplitude distribution, and frequency distribution analysis in a vibration analyzer 13. The acoustic signal amplified by the acoustic amplifier 1o is sent to the acoustic analyzer】1
The waveform, amplitude distribution, frequency distribution, and amplitude energy distribution are analyzed. The signals analyzed by the acoustic analyzer 11 and the vibration analyzer 13 are input to the comparator 14. The comparator 14 includes an acoustic analyzer 1
For the analysis signals from the vibration analyzer 1 and vibration analyzer 13, healthy signals are stored and compared with the analysis signals. If there is no deviation response in this comparison, the device is completely normal. Even in the normal case, the analysis results are stored in the signal evaluator 15. The signal evaluator 15 stores all past measurement signals and analysis signals, measurement signals and analysis signals during simulated failures, and information on failure examples of similar devices as a database. When a deviation signal is generated in the comparator 14, the data led to the signal evaluation@15 is not only stored therein, but also compared with the stored information of the signal evaluator 15 to analyze the cause of the deviation signal generation. In the analysis by the signal evaluator 15, the abnormal site and cause of the abnormality are estimated, and it is determined whether a detailed inspection is necessary. The simulated failure signal is shroud head 6, stand pipe 8. This is a signal obtained using a real model in which artificial abnormalities such as cracks and one missing part were added to representative parts of the steam/water separator 1ii7 with high failure potential. Figure 2 shows the standard impact device and its control device used in Figure 1. Acceleration sensor 2-1. Impact force sensor 2-2
The impact hammer 2-3 equipped with
It is a permanent magnet with the pole 1 anti-collision end as the S pole, and 2-4.2
-4't'2-4' . These magnets are connected to an excitation controller 2-6, and further
It is connected to the impact controller 2-7. A spring 2-8 that gives an initial velocity to the spring 2-3 is provided behind the spring 2-3, and a deflection sensor 2-9 that measures the force of the deflected spring is provided on the spring. 2-9 is connected to 2-7. 2-10 is a retractable adsorption inclusion for fixing a standard impact device to the subject, and 2-11 is a ballistic chamber 2-1 in which 2-3 is housed.
12 is a tube for extracting air, and this tube is connected to an oil pump 2-13. 2-10 is 2-5
It can be installed in close contact with the For example, place such a standard impact device at a predetermined position of the steam/water separator 7 as shown in FIG.
After positioning and lightly pressing against 7, 2-13 is activated to extract water from 2-12, and 2 can be adsorbed onto 7. When all the water in 2-12 is removed, the suction power is at its maximum. In addition, a secondary effect is brought about that the friction loss when 2-3 collides with 7 is reduced. 2-14 is 2-1
This is a pressure sensor that measures the negative pressure inside 2-1.
The water extraction work by 3 shall be controlled. After attaching 2 to 7 in this way, 2-4.2-4', 2
2-6 and 2-7 are controlled so that 2-8 is deflected until the required firing speed of 2-3 is obtained by sequentially operating -4'.... When the excitation is released when the necessary deflection of the spring 2-8 is obtained, the spring 2-3 is ejected according to the energy stored in the spring 2-8 and collides with the spring 2-7. At this time, acceleration and collision force are measured by 2-1 and 2-2. The collision speed and force can be found from this, but if you calibrate them with the spring force, you can also find it from the spring force. This impact device is characterized in that it does not require any special equipment or processing to be installed on the subject. The principle effect of this embodiment will be explained using vibration frequency as an example. For simplicity, consider the natural frequency of a cantilever beam fixed at one end at 6 as shown in FIG. Simplify m1/mo=+
273 (me: mass of 8). For the -th frequency, . Here, C is the cross-sectional shape of the stand pipe 8. The constant 1g that depends on specific gravity and longitudinal elastic modulus is 9811/s
It is fl. Now, if the mass of the steam-water separator 7 is -
ml, the frequency f1 when the standpipe is 8O and ρ is =0.78ft...(2)
becomes. Furthermore, if the connection between the steam and water separator 7 and the stand pipe 8 is cracked and the steam and water separator 7 is missing, O = 0.11! □ ...(3)
becomes. That is, it can be seen that the vibration response during normal times is clearly different from the response during abnormal times, such as when a part is missing or broken in two, and can be detected by the vibration sensor. Such abnormalities can be detected by acoustic sensors, often by frequency analysis or waveform analysis. Furthermore, since the impact conditions are always constant, changes in vibration and acoustic waveform energy and waveform amplitude can also be used as information for abnormality determination. [Effects of the Invention] According to the present invention, since the impact conditions and measurement conditions are kept constant, any change in measurement parameters can be regarded as an abnormality in the subject.
It becomes easier to judge.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a sensor device according to an embodiment of the present invention, and FIG.
The figure is a control system diagram of a standard impact device, and FIG. 3 is an explanatory diagram showing the effects of the present invention. DESCRIPTION OF SYMBOLS 1... Vibration sensor, 2... Standard impact device, 3... Acoustic sensor, 9... Positioning stage, 11... Acoustic analyzer, 13... Vibration analyzer, 14... Comparison vessel, 1
5...Signal evaluator.

Claims (1)

[Claims] 1. In a vibroacoustic abnormality determination method for testing an abnormality in a subject using a vibration sensor and an acoustic sensor, the vibration sensor is provided in contact with a specific part of the subject, and is detachable;
Furthermore, the acoustic sensor is provided at a specific position with a constant relative position to the subject and is away from the subject, and a standard impact instrument equipped with a striking effect control function is provided at a specific position of the subject. Vibration and sound of the object generated when the object is intermittently struck at specific time intervals under a striking condition are measured by the vibration sensor and the acoustic sensor, and the vibration information and acoustic information measured at each time interval are compared. A vibroacoustic abnormality determination method, characterized in that the abnormality of the subject is determined by: