Rotary machinery shell vibration test system and method based on laser vibration meter

Abstract

The invention provides a rotary machine shell vibration test system and method based on a laser vibration meter, and the system comprises the steps: the laser vibration meter is installed on an adjustable tripod, the adjustable tripod is fixed on the ground, and the adjustable tripod can adjust the height and posture of the laser vibration meter; the reflector is installed on the adjustable support, and the adjustable support can adjust the spatial position and posture of the reflector. The rotary mechanical shell base is fixed on the ground, and a tested rotary mechanical shell is rotationally mounted on the rotary mechanical shell base; and a laser beam emitted by the laser vibration meter is directionally projected to a to-be-detected area of the detected rotating machine shell after being deflected by a path of the reflecting mirror. The angle of the laser vibration meter and the angle of the reflector are adjustable, the position of a measuring point can be changed at any time by changing a light path, the vibration of the surface of the shell is measured through the laser which is a non-contact measuring mode, and the laser can still accurately measure the vibration of any position of the shell of high-temperature rotating machinery such as a gas turbine.

Description

Technical Field

[0001] This invention relates to the field of vibration testing technology for rotating machinery housings, and more specifically, to a vibration testing system and method for rotating machinery housings based on a laser vibrometer. Background Technology

[0002] In the field of rotating machinery such as electric motors and gas turbines, contact vibration sensors, such as accelerometers, are currently mainly used for vibration measurement of the casing structure. Vibration information can reflect the stability of rotating machinery in real time, and the vibration frequency and peak value can be used to analyze whether the rotating machinery is experiencing resonance, contact friction, or other phenomena. Contact sensors require fixing the sensor to a suitable position on the casing, and the fixing methods include adhesive bonding and bolting. The casing structure often has irregular surfaces such as arcs, which usually affects the strength of adhesive bonding; while bolting requires drilling threaded holes on the casing surface, which significantly increases the processing cost when vibration needs to be measured at multiple locations.

[0003] In addition, the two fixing methods mentioned above make it impossible for the sensor to flexibly change the installation position, and when the temperature of the measured structure is high, the contact sensor may experience temperature drift or even fail to work properly.

[0004] Therefore, in order to monitor the vibration of rotating machinery at different locations in real time, a non-contact vibration measurement method is needed. This method can measure the surface vibration of the shell with high precision, and can flexibly change the measurement position at any time and directly measure the vibration of high-temperature structures. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a vibration testing system and method for rotating machinery housings based on a laser vibrometer.

[0006] A vibration testing system for rotating machinery housing based on a laser vibrometer, according to the present invention, includes a laser vibrometer, a reflector, a rotating machinery housing under test, a base for the rotating machinery housing, an adjustable tripod, and an adjustable support. The laser vibrometer is mounted on the adjustable tripod, which is fixed to the ground and can adjust the height and orientation of the laser vibrometer. The reflector is mounted on the adjustable support, which can adjust the spatial position and orientation of the reflector. The base for the rotating machinery housing is fixed to the ground, and the rotating machinery housing under test is rotatably mounted on the base. The laser beam emitted by the laser vibrometer is deflected by the reflector and then directed onto the test area of ​​the rotating machinery housing under test.

[0007] Preferably, the adjustable bracket is detachably fixed to different positions on the wall via a magnetic base or vacuum suction cup.

[0008] Preferably, the adjustable bracket is equipped with a pitch angle adjustment knob and a horizontal rotation adjustment knob.

[0009] Preferably, the laser vibration meter uses a product that can simultaneously measure structural displacement and thermal deformation of the structure while measuring vibration.

[0010] Preferably, the adjustable tripod is equipped with a gimbal mechanism to enable continuous positioning of the laser vibration measuring device within the range of pitch angle 0° to 90° and horizontal rotation angle 0° to 360°.

[0011] Preferably, it also includes a vibration analysis terminal, which is connected to the laser vibrometer via a data cable or wireless module to process vibration spectrum signals in real time and generate time-domain / frequency-domain analysis reports.

[0012] Preferably, the housing of the rotating machinery being tested is rotatably mounted on the base of the rotating machinery housing via the rotating machinery shaft.

[0013] According to the present invention, a method for testing the vibration of a rotating machinery housing based on a laser vibrometer is provided. The testing method includes the following steps: S1. Install an adjustable tripod and laser vibration meter on the ground; S2. Install adjustable brackets and reflectors on the wall; S3. Adjust the angle of the laser vibrometer and the reflector so that the laser path can reach the test area of ​​the rotating mechanical housing under test. S4. Start the laser vibration meter to begin real-time monitoring of the vibration of the rotating mechanical casing under test.

[0014] Preferably, step S3 further includes the following sub-step: S3.1, adjusting the angle of the laser vibrometer so that the laser can illuminate the center position of the reflector; S3.2 Adjust the angle of the reflector so that the laser is reflected onto the test area of ​​the rotating mechanical housing, and the laser and the test area are basically perpendicular; S3.3 Adjust the focal length of the laser so that the laser can be focused into a point in the area to be tested, thereby increasing the signal strength.

[0015] Preferably, in step S4, while measuring the vibration, the time-domain signal FFT of the shell is calculated and the top five highest-valued peaks and frequencies are extracted from the FFT. When the peak value of FFT increases rapidly, it indicates that the tested rotating machinery may have a collision and wear failure, and emergency shutdown protection measures need to be taken.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses an adjustable laser vibrometer and an adjustable reflector. By changing the optical path, the position of the measurement point can be changed at any time. It measures the vibration of the outer shell surface using a non-contact laser measurement method, which is not affected by the surface temperature of the outer shell. For the outer shell of high-temperature rotating machinery such as gas turbines, the laser can still accurately measure the vibration at any position.

[0017] 2. This invention utilizes a laser vibration meter with high measurement accuracy and a wide measurement frequency range. Experimental tests have proven that existing commercial laser vibration meters can achieve a displacement resolution of 0.01nm and a sampling rate of up to 5MHz. Their measurement accuracy and frequency range are far superior to ordinary contact vibration sensors, enabling precise measurement of high-frequency vibrations in rotating machinery.

[0018] 3. By using a laser vibration meter that can measure structural displacement, this invention can measure the deformation of the shell caused by factors such as temperature rise while measuring the vibration of the shell. Attached Figure Description

[0019] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This invention primarily embodies the installation diagram of the rotating machinery housing vibration testing system based on a laser vibrometer, which measures the top of the rotating machinery housing. Figure 2 This invention primarily embodies the installation schematic diagram of the rotating machinery housing vibration testing system based on a laser vibrometer, which measures the back of the rotating machinery housing. Figure 3 This invention mainly embodies the process flow of a vibration testing method for the casing of rotating machinery based on a laser vibrometer.

[0020] The figure shows: 1. Laser vibration meter; 2. Adjustable tripod; 3. Laser beam; 4. Reflector; 5. Adjustable bracket; 6. Wall; 7. Ground; 8. Rotating machinery housing base; 9. Rotating machinery housing under test; 10. Rotating machinery shaft. Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0022] like Figures 1 to 3As shown, a vibration testing system for a rotating machinery housing based on a laser vibrometer 1, according to the present invention, includes a laser vibrometer 1, a reflector 4, a rotating machinery housing 9 to be tested, a base 8 for the rotating machinery housing, an adjustable tripod 2, and an adjustable support 5. The laser vibrometer 1 is mounted on the adjustable tripod 2, which is fixed to the ground 7, and the adjustable tripod 2 can adjust the height and orientation of the laser vibrometer 1. The reflector 4 is mounted on the adjustable support 5, which can adjust the spatial position and orientation of the reflector 4. The base 8 for the rotating machinery housing is fixed to the ground 7, and the rotating machinery housing 9 to be tested is rotatably mounted on the base 8. The laser beam 3 emitted by the laser vibrometer 1 is deflected by the reflector 4 and then directed onto the test area of ​​the rotating machinery housing 9.

[0023] This application's technical solution uses a reflector 4 to reflect the beam of a laser vibration meter 1 and illuminate the housing 9 of the rotating machinery under test. During rotation, the vibration data at this location is dynamically acquired to obtain real-time vibration displacement, velocity, or acceleration. Since the reflector 4 can arbitrarily change its installation position and angle, the laser can be reflected to any position on the housing 9 of the rotating machinery under test, thus achieving the measurement of vibration at any position using a single measuring laser. The spectrum of the vibration signal can be obtained through real-time fast Fourier transform, and the spectrum typically contains peaks at the rotor's rotational frequency. When nonlinear phenomena exist in the rotating machinery, such as contact or friction, frequencies below the rotational frequency or harmonics of the rotational frequency will appear in the spectrum. If the peak values ​​of these frequencies continuously increase, it indicates that the nonlinear phenomena in the rotating machinery are becoming increasingly severe, and instability may even be possible. Conversely, when the peak value of the rotational frequency increases sharply at each rotational frequency, it indicates that the rotational frequency may be approaching a certain natural frequency of the entire machine, causing resonance. During the development of rotating machinery, timely shutdown can be implemented when abnormal phenomena occur in the vibration spectrum during shaft testing, which can greatly avoid excessive wear and collision of the shaft system and reduce the economic and time costs associated with rotor system maintenance.

[0024] Specifically, the adjustable bracket 5 is detachably fixed to different positions on the wall 6 via a magnetic base or vacuum suction cup. The adjustable bracket 5 is equipped with a pitch adjustment knob and a horizontal rotation adjustment knob. It should be noted that the adjustable bracket 5 in this embodiment adopts a bracket of existing technology, which has a horizontal rotation joint and a pitch rotation joint to achieve spatial rotation.

[0025] The laser vibration meter 1 uses a product capable of simultaneously measuring structural displacement, and measures the thermal deformation of the structure while measuring vibration; preferably, the laser vibration meter 1 can be a laser Doppler vibration meter. The adjustable tripod 2 is equipped with a pan-tilt mechanism to achieve continuous positioning of the laser vibration measuring device within the range of pitch angle 0° to 90° and horizontal rotation angle 0° to 360°.

[0026] The housing 9 of the rotating machinery under test is rotatably mounted on the base 8 of the rotating machinery housing via the rotating machinery shaft 10. It also includes a vibration analysis terminal, which is connected to the laser vibration meter 1 via a data cable or wireless module to process the vibration spectrum signal in real time and generate a time-domain / frequency-domain analysis report.

[0027] The laser vibration meter 1 is mounted on an adjustable tripod 2, which is placed on the ground 7 beside the base 8 of the rotating machinery housing. A reflector 4 is mounted on an adjustable bracket 5, which is fixed to the wall 6. The laser beam 3 is reflected by the reflector 4 and then shines onto the rotating machinery housing 9 under test. When the rotating shaft 10 of the machinery rotates, the rotating machinery housing 9 under test vibrates, and this vibration is measured by the laser vibration meter 1.

[0028] According to the present invention, a method for testing the vibration of a rotating machinery casing based on a laser vibrometer 1 is provided. The testing method includes the following steps: S1. Install an adjustable tripod 2 and a laser vibration meter 1 on the ground 7; S2. Install the adjustable bracket 5 and the reflector 4 on the wall 6; S3. Adjust the angles of the laser vibrometer 1 and the reflector 4 so that the laser path can reach the test area of ​​the rotating mechanical housing 9 under test. S4. Start the laser vibration meter 1 to begin real-time monitoring of the vibration of the rotating mechanical housing 9 under test.

[0029] For step S3, the following sub-steps are also included: S3.1, Adjust the angle of the laser vibrometer 1 so that the laser can illuminate the center position of the reflector 4; S3.2 Adjust the angle of the reflector 4 so that the laser is reflected onto the test area of ​​the rotating mechanical housing 9, and the laser and the test area are basically perpendicular. S3.3 Adjust the focal length of the laser so that the laser can be focused into a point in the area to be tested, thereby increasing the signal strength.

[0030] In step S4, while measuring the vibration, the time-domain signal FFT of the casing is calculated, and the top five peak values ​​and frequencies with the highest values ​​are extracted from the FFT. When the peak value of the FFT increases rapidly, it indicates that the tested rotating machinery may have a collision wear failure, requiring emergency shutdown protection measures. This aims to minimize collision wear failures in the rotor system and reduce the economic and time costs associated with rotor system maintenance.

[0031] The technical solution of this application can monitor the amplitude of the casing vibration in real time through non-contact measurement data. At the same time, by post-processing the vibration data to obtain a time-frequency diagram, it is also possible to analyze the frequency change of the rotor system and the generation and development of other nonlinear frequencies.

[0032] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A vibration testing system for the casing of rotating machinery based on a laser vibrometer, characterized in that, Includes a laser vibrometer (1), a reflector (4), the housing of the rotating machinery under test (9), the base of the rotating machinery housing (8), an adjustable tripod (2), and an adjustable support (5); The laser vibration meter (1) is mounted on an adjustable tripod (2), which is fixed on the ground (7) and the adjustable tripod (2) can adjust the height and orientation of the laser vibration meter (1). The reflector (4) is mounted on an adjustable bracket (5), which can adjust the spatial position and orientation of the reflector (4); The rotating machinery housing base is fixed on the ground (7), and the rotating machinery housing (9) under test is rotatably mounted on the rotating machinery housing base (8); The laser beam (3) emitted by the laser vibrometer (1) is deflected by the path of the reflector (4) and then directed onto the test area of ​​the rotating mechanical shell (9) being tested.

2. The rotating machinery casing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, The adjustable bracket (5) can be detachably fixed to different positions on the wall (6) by means of a magnetic base or a vacuum suction cup.

3. The rotating machinery housing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, The adjustable bracket (5) is equipped with a pitch angle adjustment knob and a horizontal rotation adjustment knob.

4. The rotating machinery housing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, The laser vibration meter (1) uses a product that can simultaneously measure structural displacement and measure the thermal deformation of the structure while measuring vibration.

5. The rotating machinery housing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, The adjustable tripod (2) is equipped with a gimbal mechanism to enable continuous positioning of the laser vibration measuring device within the range of pitch angle 0° to 90° and horizontal rotation angle 0° to 360°.

6. The rotating machinery housing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, It also includes a vibration analysis terminal, which is connected to the laser vibration meter (1) via a data cable or wireless module to process the vibration spectrum signal in real time and generate a time-domain / frequency-domain analysis report.

7. The rotating machinery housing vibration testing system based on a laser vibrometer as described in claim 1, characterized in that, The housing of the rotating machinery under test is mounted on the base of the rotating machinery housing via the rotating machinery shaft.

8. A method for testing the vibration of a rotating machinery casing based on a laser vibrometer, characterized in that, The rotating machinery housing vibration testing system based on a laser vibrometer as described in any one of claims 1 to 7 includes the following steps in its testing method: S1. Install an adjustable tripod (2) and a laser vibration meter (1) on the ground (7); S2. Install an adjustable bracket (5) and a reflector (4) on the wall (6); S3. Adjust the angles of the laser vibrometer (1) and the reflector (4) so ​​that the laser path can reach the test area of ​​the rotating mechanical shell (9) under test; S4. Start the laser vibration meter (1) to begin real-time monitoring of the vibration of the rotating mechanical shell (9) under test.

9. The method for testing the vibration of a rotating machinery casing based on a laser vibrometer as described in claim 8, characterized in that, For step S3, the following sub-steps are also included: S3.1, Adjust the angle of the laser vibrometer (1) so that the laser can illuminate the center position of the reflector (4); S3.2 Adjust the angle of the reflector (4) so ​​that the laser is reflected onto the test area of ​​the rotating mechanical shell (9) and the laser and the test area are basically perpendicular; S3.3 Adjust the focal length of the laser so that the laser can be focused into a point in the area to be tested, thereby increasing the signal strength.

10. The method for testing the vibration of a rotating machinery casing based on a laser vibrometer as described in claim 8, characterized in that, In step S4, while measuring the vibration, the time-domain signal FFT of the shell is calculated, and the top five peak values ​​and frequencies with the highest assigned values ​​are extracted from the FFT. When the peak value of FFT increases rapidly, it indicates that the tested rotating machinery may have a collision and wear failure, and emergency shutdown protection measures need to be taken.

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