JP2022080737A - Method of detecting abnormality and abnormality sign of rotary machine - Google Patents

Abstract

To reliably detect abnormalities and abnormality signs generated in a rotary machine in order to prevent a severe failure from occurring in the rotary machine.SOLUTION: A method of detecting abnormalities and abnormality signs of a rotary machine includes: measurement step S1 of measuring noises or vibrations generated from the rotary machine; spectrogram creation step S2 of performing a fast Fourier transformation on the measured noises or vibrations so as to create a spectrogram for three-dimensional data of time, a frequency, and an amplitude per frequency; and abnormality determination step S3 of comparing the created spectrogram and a normal spectrogram so as to determine, according to whether or not abnormal signals appear in the created spectrogram, whether or not abnormalities and abnormality signs have been generated in the rotary machine. While the rotation speed of the rotary machine is changing, using the created spectrogram, the method detects an abnormal signal in which a larger amplitude per frequency than an amplitude per frequency in the normal spectrogram appears in proportion to the change in the rotation speed of the rotary machine.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for detecting an abnormality and a sign of abnormality in a rotating machine for detecting an abnormality and a sign of abnormality occurring in the rotating machine.

Blowers, turbines, compressors, generators, motors and the like are known as rotary machines. This rotating machine is mounted on various devices. For example, an air conditioner is equipped with a fan motor as a rotating machine. In the fan motor (rotary machine) of this air conditioner, it is important to check for abnormalities before a serious failure occurs, so we regularly perform mechanical diagnosis to check for abnormalities in the fan motor. Not only the fan motor of the air conditioner, but also other rotating machines may be subjected to mechanical diagnosis to check for abnormalities.

In the air conditioner, the mechanical diagnosis for investigating the abnormality of the fan motor is, for example, measuring the noise or vibration of the fan motor with a microphone or a vibration meter, and the measured noise or vibration of the fan motor is subjected to high-speed Fourier conversion (FFT). The frequency is analyzed and the vibration with respect to the frequency component is obtained. The abnormality of the fan motor in the air conditioner is examined depending on whether or not the vibration exceeding the preset abnormal vibration threshold value appears in the vibration with respect to the obtained frequency component.

However, it may not be possible to detect an abnormality in the fan motor by conventional mechanical diagnosis.
In an air conditioner, in a fan motor that is driven and controlled by an inverter, the set carrier frequency of the inverter (the frequency that determines the pulse width modulation cycle of the PWM control method inverter) is in the high frequency range of 2 kHz or more, so during normal operation. Also, noise and vibration due to the set carrier frequency of the inverter are generated.

Therefore, in the vibration for the frequency component obtained by the mechanical diagnosis, if the vibration due to the abnormality of the fan motor and the vibration due to the set carrier frequency of the inverter appear separately at different frequencies, it is possible to find the abnormality of the fan motor. can. However, if the vibration caused by the abnormality of the fan motor and the vibration caused by the set carrier frequency of the inverter appear at the same frequency, the vibration caused by the abnormality of the fan motor cannot be recognized.

FIG. 8 is a diagram of vibration with respect to the frequency component in the fan motor.
For example, when the set carrier frequency of the inverter is 6 kHz, as shown in the figure, in the vibration with respect to the frequency component obtained by the mechanical diagnosis, the vibration caused by the set carrier frequency of the inverter (indicated by F in the chart) is about 6 kHz. It will appear. At this time, if vibration due to an abnormality in the fan motor (indicated by E in the chart) appears at about 6 kHz, the vibrations appear to overlap at the same frequency, making it impossible to understand the vibration due to the abnormality in the fan motor. , I can't find out the abnormality of the fan motor.
This causes a problem that a serious failure occurs in the fan motor of the air conditioner.

The present invention has been made in view of such a problem, and an object of the present invention is to reliably detect an abnormality and a sign of abnormality occurring in a rotating machine in order to prevent a serious failure from occurring in the rotating machine. To be able to do it.

The present invention comprises a measuring instrument that measures noise or vibration generated by a rotating machine, and detects abnormalities and signs of abnormality generated in the rotating machine by the noise or vibration generated by the rotating machine measured by the measuring instrument. It is a method for detecting anomalies and signs of anomalies. It is a measurement process that measures noise or vibration generated from a rotating machine with a measuring instrument, and high-speed Fourier conversion is performed on the measured noise or vibration for each time, frequency, and frequency. The process of creating a spectrogram of three-dimensional data of the amplitude of It has an abnormality determination process for determining whether or not an abnormality or a sign of abnormality has occurred in a rotating machine, and using the created spectrogram, when the rotational speed of the rotating machine is changing, the normal spectrogram This is a method for detecting an abnormality and a sign of an abnormality in a rotating machine, which detects an abnormal signal in which an amplitude for each frequency, which is larger than the amplitude for each frequency, appears in proportion to a change in the rotational speed of the rotating machine.

According to the present invention, the noise or vibration generated from a rotating machine is measured by a measuring instrument, and the noise or vibration generated from the rotating machine creates a spectrogram of three-dimensional data of time, frequency, and amplitude for each frequency. Whether or not an abnormality or an abnormality sign has occurred in the rotating machine is determined based on whether or not an abnormal signal appears in the created spectrogram. As a result, it is possible to reliably detect an abnormality and a sign of abnormality in the rotating machine, and it is possible to prevent a serious failure in the rotating machine.

It is a block diagram of an air conditioner. It is a block diagram of the apparatus used in the detection method of abnormality and abnormality sign of the rotary machine of this invention. It is a flow chart of the method of detecting the abnormality and the abnormality sign of the fan motor of an air conditioner. It is a figure which shows the spectrogram of the three-dimensional data of the created time, frequency, and amplitude for each frequency. It is a figure which shows the spectrogram of FIG. 4 schematically. It is a figure which shows the spectrogram of the three-dimensional data of the time in a normal state, the frequency, and the amplitude for each frequency. It is a figure which shows the spectrogram of FIG. 6 schematically. It is a chart of vibration with respect to the frequency component in a fan motor.

An embodiment of the method for detecting an abnormality and a sign of an abnormality in a rotating machine of the present invention will be described.
The method for detecting an abnormality and an abnormality sign of a rotating machine according to the present embodiment is a method for detecting an abnormality and an abnormality sign generated in the rotating machine, and the rotating machine is a blower, a turbine, a compressor, a generator, a motor, or the like. be.
The following description is given as an example for the fan motor 2 of the air conditioner 1 which is a rotating machine. That is, the present embodiment is a method of detecting an abnormality and an abnormality sign of the fan motor 2 of the air conditioner 1, but may also be a method of detecting an abnormality and an abnormality sign of another rotating machine.

FIG. 1 is a block diagram of the air conditioner 1.
As shown in the figure, the air conditioner 1 includes a suction port 3 connected to the return air duct 11 and the like, and also includes an air outlet 4 connected to the air supply duct 12. Inside the air conditioner 1, for example, from the suction port 3 toward the outlet 4, a filter 5, a coil (heating coil and cooling coil) 7 which is a heat exchanger, a humidifier 8, a fan 6, and a fan motor 2 To prepare for each. The fan motor 2 is driven and controlled by an inverter (not shown). In the air conditioner 1, the air entering from the suction port 3 is blown out from the air outlet 4 through the filter 5, the coil 7, the humidifier 8, and the fan 6.

Next, a method of detecting an abnormality and an abnormality sign of the fan motor 2 (rotary machine) of the air conditioner 1 of the present embodiment will be described with reference to the drawings.
(Device configuration)
FIG. 2 is a block diagram of equipment used in a method for detecting an abnormality and an abnormality sign of the fan motor 2 of the air conditioner 1.
As shown in the figure, the equipment used in the method of detecting the abnormality and the sign of abnormality of the fan motor 2 of the air conditioner 1 drives and controls the measuring instrument 15 provided adjacent to the fan motor 2 of the air conditioner 1 and the fan motor 2. A processing device 17 for receiving measurement data from the measuring device 15 and receiving a signal from the inverter 16 is provided.

The measuring instrument 15 is an acoustic sensor or a vibration sensor that measures noise or vibration, and starts or ends the measurement based on a command from the processing device 17, and processes the measured noise value or vibration value as measurement data. It is transmitted to the device 17.

The processing device 17 is a computer that stores various programs and performs processing using the programs. Here, the measurement data from the measuring instrument 15 and the inverter 16 to the fan motor 2 that is driven and controlled by the inverter 16. Receives the operation start signal, operation stop signal, and rotation speed setting signal to be transmitted.

In the processing apparatus 17, the measurement data transmitted from the measuring instrument 15 is subjected to a fast Fourier transform (FFT: Fast Fourier Transform) using an existing program to perform frequency analysis, and the time, frequency, and amplitude of each frequency are analyzed. Create a spectrogram SPA of 3D data and store it.

Further, the processing device 17 also creates and stores a spectrogram SPB of three-dimensional data of the normal time, frequency, and amplitude for each frequency. When there is no abnormality in the fan motor 2 (normal time), the spectrogram SPB of the three-dimensional data of the time and frequency at the normal time and the amplitude for each frequency is measured in advance by the measuring instrument 15, and the high-speed Fourier based on the measured data. It is a spectrogram SPB of three-dimensional data of time and frequency and amplitude for each frequency created by performing conversion (FFT) and frequency analysis.

Further, the processing device 17 includes a display unit 18. The display unit 18 displays the spectrogram SPA of the created time, frequency, and three-dimensional data of the amplitude for each frequency. Further, the display unit 18 can also display a spectrogram SPB of three-dimensional data of normal time, frequency, and amplitude for each frequency.
The display unit 18 displays the created spectrogram SPA and the normal spectrogram SPB side by side on two screens. The screen of the display unit 18 can be switched, and the screen can be switched to the one-screen display of either the spectrogram SPA created from the two-screen display or the normal spectrogram SPB. You can switch from the display to the two-screen display.

(Method of detecting abnormalities and signs of abnormalities)
FIG. 3 is a flow chart of a method for detecting an abnormality and an abnormality sign of a fan motor of an air conditioner.
As shown in the figure, the method of detecting an abnormality and an abnormality sign of the fan motor 2 of the air conditioner 1 includes a measurement step (S1) for measuring noise or vibration generated from the fan motor 2 and time, frequency, and frequency. It has a spectrogram creation step (S2) for creating a spectrogram SPA of three-dimensional amplitude data, and an abnormality determination step (S3) for determining whether or not an abnormality or an abnormality sign has occurred in the fan motor 2.

In the measuring step (S1) for measuring the noise or vibration generated from the fan motor 2, the noise or vibration generated from the fan motor 2 is measured by the measuring instrument 15 provided adjacent to the fan motor 2.

That is, the operation start signal of the fan motor 2 is transmitted from the inverter 16 that drives and controls the fan motor 2 to the processing device 17 (S1-1).
The processing device 17 transmits a measurement start signal to the measuring instrument 15 based on the operation start signal (S1-2).
The measuring instrument 15 starts the measurement based on the signal of the start of the measurement (S1-3). The measurement by the measuring instrument 15 measures the noise or vibration generated from the fan motor 2 from the time of the accelerated operation in which the fan motor 2 starts and the rotation speed increases to the time of the steady operation in which the rotation speed is constant.
The noise value or vibration value measured by the measuring device 15 is transmitted to the processing device 17 as measurement data (S1-4).

In the spectrogram creation step (S2) for creating a spectrogram SPA of three-dimensional data of time, frequency, and amplitude for each frequency, high-speed Fourier transform (FFT: Fast Fourier Transfer) is performed on the noise or vibration measured by the measuring instrument 15. Then, a spectrogram SPA of three-dimensional data of time, frequency, and amplitude for each frequency is created.

That is, in the processing device 17, the measurement data (noise value or vibration value) transmitted from the measuring device 15 is subjected to a fast Fourier transform (FFT) using an existing program to perform frequency analysis, and the time and time are calculated. A spectrogram SPA of three-dimensional data of frequency and amplitude for each frequency is created (S2-1).
Next, in the processing device 17, the spectrogram SPA of the three-dimensional data of the created time, frequency, and amplitude for each frequency is stored (S2-2).

The abnormality determination step (S3) for determining whether or not an abnormality or an abnormality sign has occurred in the fan motor 2 includes a spectrogram SPA of three-dimensional data of time, frequency, and amplitude for each frequency created in the previous step, and a normal state. By comparing the time, frequency, and the spectrogram SPB of the three-dimensional data of the amplitude for each frequency, it is determined whether or not an abnormality or an abnormality sign has occurred in the fan motor 2.

That is, the spectrogram SPA of the three-dimensional data of the time, frequency, and the amplitude of each frequency created in the processing device 17, and the spectrogram SPB of the three-dimensional data of the time, frequency, and the amplitude of each frequency stored in advance in the normal state. Are displayed on two screens side by side on the display unit 18 (S3-1).

Next, the created spectrogram SPA displayed on the display unit 18 is compared with the normal spectrogram SPB (S3-2). This comparison is made by the person in charge of work. That is, the spectrogram SPA created by the person in charge of work displayed on the display unit 18 and the spectrogram SPB at the normal time are viewed.

When the created spectrogram SPA and the normal spectrogram SPB are compared, the fan motor 2 is abnormal depending on whether or not the created spectrogram SPA shows an abnormal signal K (see FIG. 4) that is not present in the normal spectrogram SPB. And whether or not an abnormality sign has occurred is determined by the person in charge of work (S3-3). That is, if the abnormal signal K appears in the created spectrogram SPA (when the abnormal signal K is detected), it is determined that the fan motor 2 has an abnormality and an abnormal sign, and if the abnormal signal K does not appear, it is determined. It is determined that no abnormality or abnormality sign has occurred in the fan motor 2.

The anomalous signal K appearing in the created spectrogram SPA will be described with reference to the drawings. The set carrier frequency of the inverter 16 in this case is 6 kHz.
FIG. 4 is a diagram showing a spectrogram SPA of three-dimensional data of the created time, frequency, and amplitude for each frequency, and FIG. 5 is a diagram schematically showing the spectrogram SPA of FIG. 4. FIG. 6 is a diagram showing a spectrogram SPB of three-dimensional data of time, frequency, and amplitude for each frequency in normal time, and FIG. 7 is a diagram schematically showing the spectrogram SPB of FIG.

The spectrogram of the three-dimensional data of the amplitude for each time, frequency and frequency shown in FIGS. 4 and 5, and the spectrogram of the three-dimensional data of the amplitude for each of the time, frequency and frequency at normal times shown in FIGS. 6 and 7. In the SPB, the horizontal axis represents time, the vertical axis represents frequency, and the color at each point represents the magnitude of amplitude for each frequency. The colors at each of these points are shown in blue (B), green (G), yellow (Y), and red (R) in the figure, for example, those with a small amplitude are blue (B) and those with a large amplitude are large. Therefore, it becomes green (G), yellow (Y), and red (R). By expressing the magnitude of the amplitude for each frequency in color in this way, it is possible to easily recognize whether or not the abnormal signal K appears, that is, the detection of the abnormal signal K becomes easy.
Further, the spectrograms SPA and SPB are shown in the diagrams schematically shown in FIGS. 5 and 7, from blue (B) to green (G), green (G) to yellow (Y), and yellow (Y) to red (R). When the color changes as shown in the above, the boundary line as shown in the figure appears clearly, but in reality, the boundary line does not appear clearly, but the color gradually changes.

In these spectrograms SPA and SPB, the magnitude of the amplitude for each frequency is expressed by color, but instead of the color, the magnitude of the amplitude for each frequency is quantified, and the amplitude for each frequency is numerically expressed at each point. It may represent the size of.

The abnormal signal K is the normal amplitude SPB in the created amplitude SPA during accelerated operation in which the rotation speed at the start of operation of the fan motor 2 increases, that is, when the rotation speed of the fan motor 2 increases (changes). The amplitude for each frequency, which is larger than the amplitude for each frequency, appears in proportion to the increase in the rotation speed of the fan motor 2.

That is, when an abnormality and an abnormality sign occur in the fan motor 2, as shown in FIGS. 4 and 5, in the created spectrogram, when the rotation speed of the fan motor 2 is increasing, the amplitude for each large frequency is large. (Yellow (Y) and red (R)) appear in proportion to the increase in the rotation speed of the fan motor 2. That is, the abnormal signal K appears in the created spectrogram. On the other hand, as shown in FIGS. 6 and 7, in the normal spectrogram, the amplitudes (yellow (Y) and red (R)) for each large frequency appear in proportion to the increase in the rotation speed of the fan motor 2. do not have.

In the spectrogram created in this way, when the amplitude for each large frequency appears in proportion to the increase in the rotation speed of the fan motor 2 (when the abnormal signal K appears), an abnormality and an abnormality sign occur in the fan motor 2. It can be determined that the frequency is high.

As described above, a spectrogram SPA of three-dimensional data of time, frequency, and amplitude for each frequency is created by the noise or vibration generated from the fan motor 2 measured by the measuring instrument 15, and the abnormal signal K is generated in the created spectrogram SPA. It is determined whether or not an abnormality and an abnormality sign have occurred in the fan motor 2 depending on whether or not the above appears. As a result, it is possible to reliably detect an abnormality and a sign of an abnormality in the fan motor 2, and it is possible to prevent a serious failure from occurring.

Further, the abnormality and the sign of the abnormality of the fan motor 2 are detected at the start of the operation of the air conditioner 1, that is, at the start of the operation of the fan motor 2, but this may be performed every day or once every 1 to 2 weeks. It may be done as needed.

Further, the detection of the abnormality and the sign of the abnormality may be performed not at the start of the operation of the fan motor 2 but at the stop of the operation of the fan motor 2.
That is, when the processing device 17 receives the operation stop signal of the fan motor 2 from the inverter 16, it transmits a measurement start signal to the measuring instrument 15 based on the signal, and the measuring instrument 15 starts the measurement. In the measurement by the measuring instrument 15, the noise or vibration generated from the fan motor 2 is measured from the time when the rotation speed of the fan motor 2 is constant to the time when the rotation at which the rotation speed decreases is stopped.

After that, as in the above-described embodiment, high-speed Fourier conversion was performed on the noise or vibration measured by the measuring instrument 15, and a spectrogram SPA of three-dimensional data of time, frequency, and amplitude for each frequency was created and created. The spectrogram SPA is compared with the spectrogram SPB in the normal state, and it is determined whether or not an abnormality or an abnormality sign has occurred in the fan motor 2 based on whether or not an abnormal signal K appears in the created spectrogram SPA. The abnormal signal K at this time is the amplitude for each frequency in the spectrogram SPB at the normal time in the created spectrogram SPA when the operation of the fan motor 2 is stopped, that is, when the rotation speed of the fan motor 2 is decreasing (changing). The amplitude for each frequency, which is larger than that of the fan motor 2, appears in proportion to the decrease in the rotation speed of the fan motor 2.

Further, the detection of abnormality and abnormality sign is not limited to the time when the operation of the fan motor 2 starts or stops, but when the rotation speed of the fan motor 2 changes (the rotation speed setting signal is transmitted from the inverter 16 to the fan motor 2). When) may be done.

Further, in the above-described embodiment, when the created spectrogram SPA and the spectrogram SPB in the normal state are compared in the abnormality determination step (S3), the person in charge of the work performs this comparison. However, not limited to this, for example, using the technique of artificial intelligence (AI), the spectrogram SPA created and the spectrogram SPB in the normal state are compared, and an abnormality and an abnormality sign occur in the fan motor 2. It may be determined whether or not it is. This makes it possible to constantly detect anomalies and signs of anomalies, unlike humans who are in charge of work.

1 ... air conditioner, 2 ... fan motor, 3 ... suction port, 4 ... outlet, 5 ... filter, 6 ... fan, 7 ... coil, 8 ... humidifier, 11 ... return air duct, 12 ... air supply duct, 15 ... Measuring instrument, 16 ... Inverter, 17 ... Processing device, 18 ... Display unit.

Claims (3)

Equipped with a measuring instrument that measures noise or vibration generated from a rotating machine, and detects abnormalities and signs of abnormality generated in the rotating machine by the noise or vibration generated by the rotating machine measured by the measuring instrument. It is a detection method of
A measurement process that measures noise or vibration generated from a rotating machine with a measuring instrument,
A spectrogram creation process that performs a fast Fourier transform on the measured noise or vibration to create a spectrogram of three-dimensional data of time, frequency, and amplitude for each frequency.
By comparing the created spectrogram with the normal spectrogram, it is judged whether or not an abnormality or a sign of abnormality has occurred in the rotating machine based on whether or not an abnormal signal that is not in the normal spectrogram appears in the created spectrogram. Abnormality judgment process to be performed and
Have,
Using the created spectrogram, when the rotational speed of the rotating machine is changing, the amplitude for each frequency, which is larger than the amplitude for each frequency in the normal spectrogram, is proportional to the change in the rotational speed of the rotating machine. A method for detecting an abnormality and an abnormality sign of a rotating machine, which comprises detecting an abnormal signal that appears. In the method for detecting an abnormality and a sign of an abnormality in a rotating machine according to claim 1.
A method for detecting an abnormality and an abnormality sign of a rotating machine, which comprises detecting an abnormal signal appearing at the start or stop of operation of a rotating machine in which the rotation speed of the rotating machine is changing by using the created spectrogram. In the method for detecting an abnormality and an abnormality sign of a rotating machine according to claim 1 or 2.
A spectrogram of three-dimensional data of time, frequency, and amplitude for each frequency is a method for detecting anomalies and signs of abnormalities in a rotating machine, characterized in that the magnitude of the amplitude for each frequency is displayed in different colors.

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