JP2860453B2 - Abnormality diagnosis method and device using wireless transmission type AE signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotating machine, for example, an unexpected contact between metal such as a moving blade fixed to a rotating shaft and a stationary blade fixed to a casing in a power generating turbine, and a rotating shaft and a fixed portion. The acoustic emission (referred to as AE) signal generated when an abnormal situation such as an unexpected contact of the labyrinth packing formed between them or a crack in the rotating shaft or the like occurs. The present invention relates to a wireless transmission type AE signal abnormality diagnosis method and apparatus for detecting and diagnosing an abnormality by wirelessly transmitting a detected AE signal.

[0002]

2. Description of the Related Art An AE signal is an elastic wave signal generated by energy released when a solid is deformed or destroyed. Abnormality of a rotating machine such as a power generation turbine described above is utilized by using such an AE signal. The method of detecting and diagnosing is described in, for example, JP-A-54-39153 and
As disclosed in, for example, Japanese Patent Application Laid-Open No. 7026/1995, it is conventionally known.

FIG. 4 shows an AE generally known in the art.
FIG. 5 is a schematic block diagram of an apparatus to which an abnormality diagnosis method using a signal is applied, and FIG. 5 is a block diagram of the apparatus. A to detect the AE signal on the rotating body 20 side such as a moving blade fixed to the rotating shaft 23
An E sensor 1, a preamplifier 2 for amplifying an AE signal detected by the AE sensor 1, and an FM modulation circuit 3 for modulating the amplified AE signal into a frequency band suitable for wireless transmission.
And a transmitting unit 30 including an amplifier 4 for power-amplifying the modulated signal and a transmitting antenna 5, and a stationary unit fixedly installed at a position away from the rotating unit 20 (see FIG. The receiving device 40 includes a receiving antenna 6, an FM receiving circuit 7, and an FM demodulating circuit 8 as a receiving device 40. The FM demodulating circuit 8 of the receiving device 40 receives and demodulates the received FM. An AE analyzer 9 is connected as diagnostic means for diagnosing the abnormality of the rotating body 20 by analyzing the signal obtained.

[0004]

SUMMARY OF THE INVENTION In the above-described abnormality diagnosis method and apparatus using a wireless transmission type AE signal,
The transmission / reception sensitivities of the antennas 5 and 6 vary depending on the rotation angle of the rotator 20. Therefore, the amplitude changes in synchronization with the rotation speed of the rotator 20, and a rotation synchronization signal having a waveform substantially as shown in FIG. S1 (hereinafter referred to as a BGN signal) is transmitted wirelessly.

The AE signal S2 detected by the AE sensor 1 when an abnormal situation such as metal-to-metal contact between the moving blade and the stationary blade, contact of the labyrinth packing, or cracking of the rotating shaft occurs in the power generation turbine described above. , A change in amplitude similar to the above is observed, and the AE signal S2 is transmitted while being superimposed on the BGN signal S1 having the above-described waveform as shown in FIG. 7A or 7B. Will be. Therefore, it is sometimes difficult to distinguish between the AE signal S2 transmitted when an abnormality occurs on the rotating body 20 side and the BGN signal S1 which is always transmitted even when there is no abnormality. There was a problem that it was not possible to detect with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enhances the accuracy of identifying an AE signal transmitted by being superimposed on a BGN signal having a change in amplitude, thereby reliably detecting the occurrence of an abnormality at an early stage. It is an object of the present invention to provide a method and an apparatus for diagnosing abnormalities based on a wireless transmission type AE signal.

[0007]

In order to achieve the above object, a method of diagnosing an abnormality by a wireless transmission type AE signal according to the present invention is to modulate the frequency of a signal from a sensor mounted on a rotating body and detecting the AE signal. In the method of diagnosing the abnormality of the rotating body by receiving and demodulating the transmission signal and detecting the rotation start point of the rotating body, a rotation reference signal is generated and synchronized with the rotation reference signal. Let me go BG
A signal having a phase opposite to that of the N signal is generated, a signal having the opposite phase is applied to an amplifier on the receiving side, and the BGN signal is canceled by the opposite phase signal to output a signal having a steady waveform.
It is characterized in that an AE signal transmitted by being superimposed on a GN signal is detected.

[0008] Further, an abnormality diagnosis apparatus using a wireless transmission type AE signal according to the present invention is an AE sensor mounted on a rotating body for detecting an AE signal generated from the rotating body, and amplifies the AE signal detected by the AE sensor. A preamplifier, frequency modulation means for frequency-modulating the amplified AE signal,
A transmitting unit that wirelessly transmits the frequency-modulated signal; a receiving unit that receives and demodulates the signal from the transmitting unit; and a diagnostic unit that analyzes the received signal and diagnoses an abnormality of the rotating body. An abnormality diagnosis device based on a wireless transmission type AE signal, comprising: a rotation angle detection device for detecting a rotation start point of the rotating body to generate a rotation reference signal; and a rotation reference signal generated by the rotation angle detection device. And an anti-phase signal generating means for generating a signal having an anti-phase to the BGN signal. The anti-phase signal generated by the anti-phase signal generating means is applied to an amplifier on the receiving means side to generate a BGN signal. The present invention is characterized in that a signal having a steady waveform is output by canceling out the AE signal, and the AE signal transmitted by being superimposed on the BGN signal is detected by the diagnostic means.

According to the present invention, a signal having a phase opposite to that of the BGN signal is generated in synchronization with a rotation reference signal generated by detecting a rotation start point of the rotating body, and the signal having the opposite phase is generated. By being applied to the receiving side amplifier,
As a result, a signal having a steady waveform obtained by canceling the BGN signal is obtained . Therefore, when an abnormality occurs on the rotating body side,
Only the AE signal that is detected by the AE sensor and transmitted by being superimposed on the BGN signal can create a signal waveform situation that is significantly prominent with respect to the steady waveform signal. A
The discrimination from the E signal is improved, and it is possible to reliably and accurately detect the occurrence of an abnormality such as a failure in the rotating body at an initial stage.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an apparatus used for implementing an abnormality diagnosis method using a wireless transmission type AE signal according to the present invention.
Since 0 and 40 are the same components as those in the conventional example shown in FIG. 5, the corresponding portions are denoted by the same reference numerals and description thereof will be omitted. The outline of the rotary machine to which this apparatus is applied is as shown in FIG.

In FIG. 1, reference numeral 10 denotes a rotation angle detection device comprising a proximity switch or the like, which detects a rotation starting point of a rotating body 20 (see FIG. 4) in the rotary machine M and generates a rotation reference signal. Reference numeral 11 denotes an arbitrary waveform generator, which constitutes an anti-phase signal generating means for generating a signal having an opposite phase to the BGN signal in synchronization with the rotation reference signal generated by the rotation angle detector 10. This arbitrary waveform generator 11
BGN signal and antiphase signal generated by the receiving device
Offset by applied to BGN signal 40 of the amplifier 12 is configured as BGM signal standing wave form is output
You.

Next, an operation of diagnosing an abnormality of the rotating machine M by the abnormality diagnosis apparatus based on the wireless transmission type AE signal configured as described above will be described. With the rotation of the rotating body 20 of the rotary machine M, the rotation start point is detected by the rotation angle detection device 10 to generate a rotation reference signal, and the generated rotation reference signal is input to the arbitrary waveform generation device 11. As a result, a signal having an opposite phase to the rotation reference signal is generated in synchronization with the rotation reference signal, and the signal having the opposite phase is received.
By being applied to the amplifier 12 on the device 40 side , the transmission device
Transmission from the 30 side to the receiving device 40 side via the antennas 5 and 6
BGN signal S1 waveform indicated by to come in FIG. 2 (a)
Is offset, BG standing wave shape as shown in shown in FIG. 2 (b)
The N signal S3 is output from the amplifier 12 .

Next, the standing wave output from the amplifier 12
BGN signal S3 in the form is received by the FM receiver circuit 7, and demodulated by the FM demodulation circuit 8, the demodulated signal of that is A
The abnormality is input to the E-analysis device 9 and the abnormality of the rotating body 20 is diagnosed.

As described above , when an abnormality such as contact between metal and labyrinth packing occurs on the rotating body 20 side, the AE sensor 1 detects the BGN signal S1 having a waveform shown in FIG. 7A or 7B. Is superimposed on and transmitted
Of the receiving device 40 that receives the incoming AE signal S2
12, the BGN signal S1
To output a BGN signal S3 having a steady waveform.
As a result, as shown in FIG. 3, a signal waveform situation in which only the AE signal S2 significantly protrudes with respect to the BGN signal S3 having the steady waveform is created. Signal S3 and AE
The discrimination from the signal S2 is enhanced, and the occurrence of an abnormality accompanying the analysis by the AE analyzer 9 can be accurately detected at an early stage .

[0015]

As described above, according to the first and second aspects of the present invention, the BGN signal having a waveform having a change in amplitude substantially synchronized with the rotation speed of the rotating body is produced by the rotation of the rotating body.
On the receiving side, by canceling the signal with the opposite phase to that of the signal and outputting a signal of a steady waveform, when an abnormality occurs on the rotating body side, only the AE signal detected by the AE sensor and superimposed on the BGN signal and transmitted is transmitted. It is possible to create a signal waveform situation that is significantly prominent with respect to the stationary waveform signal. Therefore, despite the wireless transmission method, BG
It is possible to improve the accuracy of distinguishing between the N signal and the AE signal,
When abnormalities such as unexpected contact between metal parts or failures occur on the rotating body, the fact can be detected reliably and accurately at the initial stage, and the safety and maintainability of the rotating machine are significantly improved. Is achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus used for performing an abnormality diagnosis method using a wireless transmission type AE signal according to the present invention.

FIG. 2 is an explanatory diagram showing a waveform change of a BGN signal having the configuration according to the embodiment.

FIG. 3 is an explanatory diagram showing a signal waveform state created by the present invention.

FIG. 4 is a schematic view of an apparatus to which an abnormality diagnosis method using an AE signal generally known in the related art is applied.

FIG. 5 is a block configuration diagram of the above device.

FIG. 6 is a waveform diagram of a general BGN signal.

FIG. 7 is an explanatory diagram of a signal waveform state in a state where an AE signal is superimposed on the BGN signal of FIG. 6;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 AE sensor 2 preamplifier 3 FM modulation circuit (frequency modulation means) 5 transmission antenna (transmission means) 6 reception antenna 7 FM reception circuit (reception means) 8 FM demodulation circuit (reception means) 9 AE analysis device (diagnosis means) 12 reception Side amplifier 20 Rotating body S1 Waveform BGN signal with amplitude change S2 AE signal S3 BGN signal of steady waveform

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeo Tsukamoto 3-3-22 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Inside Kansai Electric Power Company (72) Inventor Koji Fukuda 3- 14-40 Senrioka, Settsu-shi, Osaka Inside Toko Seiki Co., Ltd. (72) Inventor Hideki Umekawa 3--14-40 Senrioka, Settsu-shi, Osaka Prefecture Inside Toko Seiki Co., Ltd. (72) Takumi Nakano 3-14-40 Senrioka, Settsu-shi, Osaka Tokou Toko Seiki Co., Ltd. (56) References JP-A-54-46080 (JP, A) JP-A-56-63220 (JP, A) JP-A-57-35752 (JP, A) JP-A-5-99790 (JP) , A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01H 17/00 G01M 19/00 G01N 29/14

Claims (2)

(57) [Claims] 1. A signal from a sensor mounted on a rotating body and detecting an acoustic emission (AE) signal is frequency-modulated and transmitted wirelessly, and the transmission signal is received and demodulated to detect an abnormality of the rotating body. In the diagnosis method, a rotation reference signal is generated by detecting a rotation start point of the rotating body, a signal having a phase opposite to the rotation synchronization signal is generated in synchronization with the rotation reference signal, and a signal having the opposite phase is received. A signal having a steady waveform is output by applying the signal to the amplifier on the side and canceling the rotation synchronizing signal with the opposite phase signal, and the signal A is superimposed on the rotation synchronizing signal and transmitted.
An abnormality diagnosis method using a wireless transmission type AE signal, comprising detecting an E signal. 2. An AE sensor mounted on a rotating body for detecting an AE signal generated from the rotating body, a preamplifier for amplifying an AE signal detected by the AE sensor, and a frequency modulation for frequency-modulating the amplified AE signal. Means, transmitting means for wirelessly transmitting the frequency-modulated signal, receiving means for receiving and demodulating a signal from the transmitting means, and diagnosing means for analyzing the received signal and diagnosing an abnormality of the rotating body. An abnormality diagnosis device based on a wireless transmission type AE signal, comprising: a rotation angle detection device that detects a rotation start point of the rotating body to generate a rotation reference signal; and a rotation reference signal generated by the rotation angle detection device. ; and a reverse phase signal generating means for generating a signal of opposite phase to the rotation synchronizing signal in synchronism with, the reverse phase signal generated by the anti-phase signal generating means Outputs a signal of the standing wave form by offsetting the amplifier to the rotation synchronizing signal is applied Shin means side, to the AE signal is transmitted while superimposed on the rotation synchronizing signal is configured to detect by the diagnostic means Wireless transmission type A characterized by:
An abnormality diagnosis device based on the E signal.