JPH0587620A - Acoustic vibration monitoring apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] To reliably detect transient shock vibrations that suddenly occur in equipment and peculiar acoustic vibrations that constantly occur when equipment malfunctions. [Structure] The spectrum analysis unit 2 performs spectrum analysis in response to a completion signal of a change in the operation conditions from the operation condition comparison / determination unit 1. The output signal from the band cut filter 3 is
It is input to the first RMS converter 4 and the second RMS converter 5 having different time constants. The output signal of the second RMS converter 5 is
Input to the threshold setting unit 6. The output signals from the first RMS converter 4 and the threshold value setting unit 6 are sent to the impact abnormality comparison / determination unit 7
Input to and monitor for impact abnormalities. Singular vibration comparison determination unit 8
The vibration mode comparison / determination unit 9 monitors the acoustic vibration based on the spectrum analysis output data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic vibration monitoring device for main equipment in a nuclear power plant or the like.

[0002]

2. Description of the Related Art In general, acoustic vibrations that occur when equipment is abnormal are caused by the following abnormal situations. During the secular change of the equipment and the initial adjustment stage, rubbing and loosening of parts occur, and peculiar mechanical vibration and fluid vibration occur. Due to the damage of parts and the inclusion of foreign matter, etc., the parts collide with other parts in the equipment, and transient shock vibration suddenly generated and characteristic acoustic vibration due to rubbing occur.

If abnormalities of the equipment can be detected early from such acoustic vibrations, it becomes possible to deal with equipment maintenance at the initial failure stage.

[0004]

By the way, the main equipment such as a nuclear power plant often contains a lot of steady acoustic vibrations even in a normal state. Therefore, when the acoustic vibration related to the device abnormality is hidden by the acoustic vibration of the large amplitude, it is difficult to monitor the acoustic vibration of the device and detect the abnormality. Further, even when the frequency and the amplitude of the acoustic vibration having the large amplitude change depending on the operating condition, it is not easy to monitor the acoustic vibration of the device and detect the abnormal state.

The present invention has been made in consideration of such a point, and a transient shock vibration suddenly generated in the device,
Another object of the present invention is to provide an acoustic vibration monitoring device capable of easily and accurately detecting a peculiar acoustic vibration that is constantly generated when an abnormality occurs in the equipment during operation of a main equipment such as a nuclear power plant.

[0006]

As a means for achieving the above object, the present invention relates to an acoustic vibration monitoring apparatus for main equipment in a nuclear power plant or the like; comparing changes in operating conditions based on operating condition information of the equipment. Operating condition comparison and determination means; when the operating condition changes, the acoustic vibration signal from the target device is spectrally analyzed after the operating condition change is completed,
Spectrum analysis means for outputting a normal acoustic component generated depending on operating conditions of the equipment; and based on the output from the spectrum analysis means and the acoustic vibration signal from the target equipment,
Band-cut filtering means for removing only dominant acoustic components in a normal time; first RMS value output means for outputting an RMS value having a small time constant so that shock vibration also follows acoustic vibration after filtering And; second RMS value output means for outputting an RMS value having a large time constant that hardly follows transient impact vibration with respect to acoustic vibration after filtering; and RMS value output from the second RMS value output means. RMS threshold value setting means for setting an RMS threshold value capable of following a vibration of an appropriate magnitude proportional to; RMS threshold value setting means, first RMS value output means, and operating condition comparison / judgment means.
Shock abnormality comparison / determination means for determining the presence / absence of transient shock vibration in a constant operation state; specific vibration in a constant operation state based on each output signal from the first RMS value output means, spectrum analysis means and operation condition comparison / determination means And a vibration mode comparison / judgment means for judging presence / absence of a peculiar vibration mode in each operating state based on an output signal from the spectrum analysis means. And

[0007]

In the acoustic vibration monitoring apparatus according to the present invention, the spectrum analysis means performs the spectrum analysis by the operation condition change completion signal from the operation condition comparison and determination means.
Then, a new cut frequency, a new threshold value for determining a specific vibration, determination data, or the like is output to the band cut filtering means, the specific vibration comparison determination means, the vibration mode comparison determination means, or the like.

The output signal from the band cut filtering means is input to the RMS value output means having different time constants, and the output signal from the second RMS value output means is
It is input to the RMS threshold setting means. Then, these output signals are input to the impact abnormality comparison and determination means, and the impact abnormality is monitored. Further, the singular vibration comparison and determination means and the vibration mode comparison and determination means monitor the acoustic vibration based on the data output by spectrum analysis. Therefore, it is possible to easily and accurately detect the transient shock vibration generated in the device and the peculiar acoustic vibration that is constantly generated when the device is abnormal during the operation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an example of an acoustic vibration monitoring apparatus according to the present invention. This apparatus is a detector (acceleration sensor, AE sensor, microphone) capable of sensitively extracting acoustic vibration of a target device as an input signal. Output signal from
Also, an output signal related to operating condition information (pump rotation speed, valve opening degree, etc.) of the target device is used.

Further, the acoustic vibration monitoring apparatus includes an operating condition comparison / determination unit 1, a spectrum analysis unit 2, a band cut filter 3, a first RMS converter 4, a second RMS converter 5, a threshold value setting unit 6, and an impact abnormality comparison. The determination unit 7, the specific vibration comparison determination unit 8, and the vibration mode comparison determination unit 9 are provided.

The operating condition comparison / determination unit 1 is adapted to compare and determine the change in the operating condition from the operating condition information of the equipment. When the operating condition changes, the spectrum analysis unit 2
However, the spectrum of the raw signal before the band cut filter 3 is analyzed after the change of the operating conditions is completed. Then, from the spectrum analysis unit 2, a singular vibration comparison for detecting a dominant acoustic vibration component in a normal state that occurs depending on operating conditions and an acoustic vibration that gradually increases due to abnormality / deterioration of equipment. Reference RMS to determination unit 8
The value and the frequency component data for vibration mode comparison determination corresponding to the operating condition are calculated and output.

The band cut filter 3 is adapted to remove only the dominant acoustic vibration component in the normal state based on the spectrum-analyzed data. This band
The cut filter 3 removes the acoustic vibration component that affects the reliability of monitoring based on the dominant acoustic vibration component data obtained by the analysis to prevent erroneous determination of specific vibration or shock abnormality, and In order to improve the sensitivity, the band cut area setting is changed.

The operating condition comparison / judgment unit 1 is provided with a shock abnormality comparison / judgment unit 7 for detecting a transient shock vibration that is suddenly generated when the driving condition is changed, and gradually due to abnormality / deterioration of equipment. As shown in FIG. 2, the judgment bypass signal is input to the singular vibration comparison / determination unit 8 that detects acoustic vibrations that become large, from the start of the change in the operating conditions to immediately after the completion of the band / cut region setting change of the band / cut filter 3. Is output to prevent erroneous operation of the determination units 7 and 8.

The first RMS converter 4 outputs an RMS value with a small time constant that follows the transient shock vibration from the low frequency component to the high frequency component with respect to the filtered acoustic vibration. On the other hand, the second RMS converter 5 sets a large time constant that hardly follows transient shock vibration, and outputs an RMS value that follows only fluctuations in low-frequency components.

Further, the threshold value setting section 6 has a built-in DC amplifier capable of setting an arbitrary gain, and the second RMS converter 5
The level proportional to the output signal of can be set.

The impact abnormality comparison / determination unit 7 follows the output signal from the threshold value setting unit 6 which hardly follows the transitional impact vibration as a reference, and the first which follows the transitional impact vibration.
The output signal from the RMS converter 4 is compared (whether or not it is exceeded) in real time, and as shown in FIGS. 3 (A) and 3 (B), the presence or absence of transient shock vibration in a constant operating state. Is determined. The output signal from the impact abnormality comparison / determination unit 7 serves as a recording request signal to the impact vibration recording device mounted in the next stage.

In the shock vibration recording device, if an arrangement is made such that the data immediately before the current time is always temporarily stored as the acceleration signal before the band cut filter 3, the output from the shock abnormality comparison / determination unit 7 Since the data immediately before the impact can be saved, transient impact vibration data, which is important for device diagnosis, can be reliably collected immediately before the impact.

The singular vibration comparison / determination unit 8 has a reference RMS threshold value for detecting acoustic vibration that is gradually increased due to the abnormality / deterioration of the equipment obtained by the spectrum analysis unit 2,
The output signal from the first RMS converter 4 capable of following the variation from the low frequency to the high frequency component is compared (whether or not it is exceeded) in real time, and as shown in FIG. The presence or absence of the peculiar vibration in is determined.

Further, the vibration mode comparison / judgment unit 9 includes the vibration mode comparison / judgment data (representative acoustic vibration frequency and acoustic vibration overall value) corresponding to the operating conditions obtained by the spectrum analysis unit 2, and the spectrum analysis unit 2 in advance. Compared with the vibration mode determination threshold data (upper and lower thresholds of the representative acoustic vibration frequency and upper and lower thresholds of the acoustic vibration overall) corresponding to the operating conditions obtained in (whether or not it is within the upper and lower thresholds), As shown in FIGS. 5A and 5B, the presence or absence of the specific vibration mode in each operating state is determined.

In the above configuration, the output signal related to the operating condition information is used to automatically determine the change in the operating condition of the equipment, and when the change occurs, the sound in the normal condition is generated depending on the operating condition. The vibration component is spectrally analyzed and output. Then, based on the analysis output data, the setting of the band cut filter 3 that removes only the dominant acoustic vibration component is changed.

Further, based on the analysis output data, the singular vibration detection RMS threshold value corresponding to the operating state is output to the singular vibration comparison / determination unit 8 which detects acoustic vibration components that gradually increase. Further, in the vibration mode comparison / determination unit 9,
Based on the analysis output data, the presence / absence of acoustic vibration having different vibration modes that do not correspond to the respective operating conditions is compared and determined.
In addition, when the operating conditions change, the impact abnormality comparison determination unit 7
A determination bypass signal is output from the operating condition comparison / determination unit 1 to the and specific vibration comparison / determination unit 8.

Spectral analysis If the output data and the same operating condition data registered as a database (frequency of main acoustic vibration, effective value range of all bands, etc.) do not match within the allowable value range, this It is determined that a peculiar acoustic vibration that does not correspond to each of the above operating conditions is detected, and it is output that the vibration mode is abnormal.

By using the acoustic vibration signal in which only the frequency component of the main acoustic vibration is removed by the band cut filter 3, a transient shock vibration that occurs suddenly or a peculiar acoustic vibration that gradually increases , Is compared with the reference threshold, and acoustic vibration monitoring is sequentially performed.

The reference threshold value for detecting a peculiar acoustic vibration that becomes gradually larger is the RMS value of the acoustic vibration considering the band cut filter 3 minutes from the data output by analysis when the operating conditions change. , A value multiplied by an allowable value that is regarded as a normal range is used.

As described above, it is possible to eliminate the erroneous determination of the device abnormality that has been often caused by the conventional vibration monitoring, and to reliably collect the transient shock vibration data important for diagnosing the device. it can. In addition, by issuing an alarm, it is possible to notify the equipment administrator of the equipment abnormality early, and because the equipment abnormality can be detected early,
It is possible to deal with equipment maintenance at the initial failure stage.

FIG. 6 shows a second embodiment of the present invention, in which a plurality of acceleration sensors are attached to the outer wall of the device, and acoustic vibration signals P1 and P from these acceleration sensors are provided.
2, P3, P4, P5, a plurality of acoustic vibration monitoring devices 1
0, 20, 30, 40, 50, and each output signal from each of the acoustic vibration monitoring devices 10, 20, 30, 40, 50 is input to the shock vibration recording device 60, and the output is shocked. The input is made to the vibration quantitative evaluation device 70.

The shock-vibration recording apparatus 60 uses a sampling clock capable of sufficiently reproducing a plurality of vibration waveforms before the occurrence of a transient shock-vibration by the timing in which the transient shock-vibration is first hit by a plurality of acceleration sensors. Sampling is performed, and the time until the transient shock vibration disappears is recorded from a plurality of vibration data, and is recorded and output to the shock vibration quantitative evaluation device 70 in the next stage. In addition, the impact vibration quantitative evaluation device 70 includes the impact vibration recording device 6
Using the vibration data obtained at 0, position estimation, impact energy estimation, mass estimation, etc. for an impact object are performed, and data for each estimation result is output.

According to this embodiment, it is possible to diagnose an impact object generated in the equipment.

FIG. 7 shows a third embodiment of the present invention, in which an acceleration sensor is attached to the outer wall of each of the plurality of devices A, B, C, D and E, and the sound from each acceleration sensor is generated. The vibration signal is transmitted to a plurality of acoustic vibration monitoring devices 10, 20,
While inputting to 30, 40, 50, each output signal from each of these acoustic vibration monitoring devices 10, 20, 30, 40, 50 is input to the acoustic vibration recording analysis device 80, and its output is quantitatively evaluated for acoustic vibration. The data is input to the device 90.

The acoustic vibration recording / analysis device 80 performs correlation analysis between the vibration signal and the operating condition information signal, RMS data correlation analysis, etc., and outputs the analysis result to the acoustic vibration quantitative evaluation device 90 in the next stage. Is becoming Further, the acoustic vibration quantitative evaluation device 90 uses the information obtained by the acoustic vibration recording / analysis device 80 to load the devices A, B, C, D, and E, the wear condition, the eccentricity / declination condition, and the The balance state, the contact state, and the like are quantitatively estimated, and data about each estimation result is output.

According to this embodiment, it is possible to diagnose abnormal vibrations and vibration modes of various devices.

[0033]

As described above, according to the present invention, a transient shock vibration suddenly generated in a main device such as a nuclear power plant or a peculiar acoustic vibration that is constantly generated when the device is over is generated. It is possible to detect easily, accurately and early during the operation of.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an acoustic vibration monitoring device according to a first embodiment of the present invention.

2 is a timing chart of each part in the apparatus of FIG.

FIG. 3A is a graph showing a change over time when a transient impact vibration determination is performed. (B) is a graph showing the time change of the output signal of the threshold setting unit.

FIG. 4 is a graph showing changes over time in specific vibration comparison determination.

FIG. 5A is a graph showing a time change of dominant acoustic vibration frequency determination. (B) is a graph showing the change over time in the overall value determination of the acoustic vibration signal.

FIG. 6 is a block configuration diagram showing an acoustic vibration monitoring device according to a second embodiment of the present invention.

FIG. 7 is a block configuration diagram showing an acoustic vibration monitoring device according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Operating Condition Comparison Judgment Unit 2 Spectrum Analysis Unit 3 Band Cut Filter 4 First RMS Converter 5 Second RMS Converter 6 Threshold Setting Unit 7 Impact Abnormality Comparison Judgment Unit 8 Singular Vibration Comparison Judgment Unit 9 Vibration Mode Comparison Judgment Unit

Claims (1)

[Claims] 1. An acoustic vibration monitoring apparatus for main equipment in a nuclear power plant or the like, and an operating condition comparison / determination means for comparing and judging a change in the operating condition based on the operating condition information of the equipment, and an operation when the operating condition changes. Spectral analysis of the acoustic vibration signal from the target equipment after the completion of the condition change, and the spectrum analysis means that outputs the acoustic component at normal time that occurs depending on the operating conditions of the equipment, and the output from the spectrum analysis means and the target equipment Based on the acoustic vibration signal, band cut filtering means to remove only the dominant acoustic component in normal time, and output RMS value with small time constant so that shock vibration also follows acoustic vibration after filtering First to do
RMS value output means and RM having a large time constant so as to hardly follow transient shock vibration with respect to acoustic vibration after filtering
Second RMS value output means for outputting an S value, RMS threshold setting means for setting an RMS threshold value capable of following an appropriate magnitude of vibration proportional to the RMS value output from the second RMS value output means, and RMS threshold setting means. A first RMS value output means and a spectrum analysis means, and an impact abnormality comparison and determination means for determining the presence or absence of a transient shock vibration in a constant operating state based on the output signals from the first RMS value output means and the operating condition comparison and determination means. And based on the output signals from the operating condition comparison and determination means, the specific vibration comparison and determination means for determining the presence or absence of specific vibration in a constant operating state, and based on the output signal from the spectrum analysis means, An acoustic vibration monitoring device comprising: a vibration mode comparison / determination unit for determining presence / absence.