CN112378506B - A synchronous test method for the vibration of a tubular hydraulic mechanical runner and outer wall - Google Patents

Abstract

The invention discloses a synchronous testing method for the vibration of a tubular hydraulic mechanical runner and an outer wall, which specifically includes the following steps: step 1, processing a runner chamber based on different objects to be tested; step 2, selecting according to step 1 The test object is arranged with laser vibrometer, photoelectric encoder and piezoelectric vibration velocity sensor; step 3, use computer to synchronously collect the output signals of rotary photoelectric encoder, two laser vibrometers and all piezoelectric vibration velocity sensors , cross-power spectrum analysis and cross-correlation analysis can be performed on the measured signals to determine the correlation between the signals. The invention does not affect the normal operation of the tubular hydraulic machinery at all in the measurement process, and can realize the synchronous measurement of the vibration of the runner and the vibration of the outer wall.

Description

A Synchronous Test Method for Vibration of Runner and Outer Wall of Through-flow Hydraulic Machinery

technical field

The invention belongs to the technical field of hydraulic mechanical equipment, and relates to a synchronous testing method for the vibration of a through-flow hydraulic mechanical runner and an outer wall.

Background technique

Tubular hydraulic machinery, including tubular water pumps, water turbines and marine propellers, etc., plays an irreplaceable role in the field of national economy in our country, especially the stability of tubular hydraulic machinery involving military use is more concerned by designers top priority. The runner of the through-flow hydraulic machinery is the active part of the whole equipment. The unstable flow and friction caused by the high-speed rotation in the water are the main reasons for the vibration of the through-flow hydraulic machinery. Therefore, the realization of the through-flow hydraulic machinery Synchronous detection and analysis of wheel and outer wall vibration has important practical significance for judging the running state of tubular hydraulic machinery.

Contents of the invention

The purpose of the present invention is to provide a synchronous test method for the vibration of the runner and the outer wall of the through-flow hydraulic machinery. Synchronous measurement of vibration.

The technical solution adopted in the present invention is a synchronous testing method for the vibration of the runner and the outer wall of a through-flow hydraulic machine, which specifically includes the following steps:

Step 1, processing the runner chamber based on different objects to be tested;

Step 2, according to the test object selected in step 1, arrange the laser vibrometer, photoelectric encoder and piezoelectric vibration velocity sensor;

Step 3, use the computer to synchronously collect the output signals of the rotary photoelectric encoder, two laser vibrometers and all piezoelectric vibration velocity sensors, and perform cross-power spectrum analysis and cross-correlation analysis on the measured signals to determine the relationship between the signals. connection relation.

The present invention is also characterized in that,

In step 1:

If the object to be tested is a through-flow hydraulic mechanical model in the laboratory, the entire runner chamber shall be processed with high-transparency plexiglass material;

When the object to be tested is a through-flow hydraulic machine in engineering applications, it is necessary to process two circular circles at an angle of 90° in the circumferential direction at the axial position on the runner chamber that is aligned with any cross-section of the runner discharge cone. The window is closed with a high transparent plexiglass cover.

The radius R of the window is greater than 50mm.

The specific process of step 2 is:

Step 2.1, when the test object is the model of the tubular hydraulic machinery in the laboratory, the runner chamber of the tubular hydraulic machinery has been processed with high-transparency plexiglass material in step 1, so the visible laser of the laser vibrometer can Effectively penetrate the runner chamber and focus on the runner discharge cone. At this time, the two laser vibrometers are arranged at the same axial position and arranged at a circumferential angle of 90 degrees, so that the directions of the two laser beams can be aligned. 90 degrees on the discharge cone of the runner, so that the vibration signals in two directions with a 90-degree circumferential phase of the runner can be obtained;

When the test object is a through-flow hydraulic machine in engineering applications, two circular windows with a circumferential angle of 90° have been processed in the runner chamber of the through-flow hydraulic machine in step 1. The two circular windows are due to the use of The high-transparency plexiglass cover is closed, so the laser can effectively penetrate and focus on the water discharge cone of the runner. At this time, two lasers with a circumferential angle of 90 degrees are arranged on the same plane as the axial position of the circular window. Vibrometer, the circumferential positions of the laser beams of the two laser vibrometers are the same as the circumferential positions of the two circular windows, so as to ensure that the two laser beams are respectively injected from the two circular windows to obtain the circumferential phase of the runner Vibration signals in two directions at 90 degrees;

Step 2.2, install the rotary photoelectric encoder on the extended shaft of the tubular hydraulic machinery, and lead out the signal output line to the multi-channel synchronous digital signal collector; connect the signal output lines of the two laser vibrometers to the multiple Channel synchronous digital signal collector;

Step 2.3, according to the specific test location requirements, install multiple piezoelectric vibration velocity sensors on the outer wall of the water inlet pipe, runner chamber and draft tube, and connect the signal output lines of the arranged piezoelectric vibration velocity sensors to Multi-channel synchronous digital signal acquisition device, the output line of the multi-channel synchronous digital signal acquisition device transmits the data collected synchronously to the computer.

In step 2.1, when the test object is a through-flow hydraulic mechanical model in the laboratory, the radial distance between the two laser vibrometers and the water discharge cone of the runner must be within the range of 0.2 meters to 30 meters;

When the test object is a through-flow hydraulic machine used in engineering applications, the radial distance between the two laser vibrometers and the water discharge cone of the runner shall not exceed 30 meters.

In step 2.3, the number of piezoelectric vibration velocity sensors should be less than the number of remaining channels after the multi-channel synchronous digital signal acquisition device is connected with a rotary photoelectric encoder and two laser vibrometers.

During the test, if the multi-channel synchronous digital signal collector still has redundant channels, it can also be connected to a piezoelectric pressure pulsation sensor that monitors the pressure pulsation inside the flow channel to realize the pressure pulsation in the flow channel of the through-flow hydraulic machinery, the runner Simultaneous measurement of vibration and external wall vibration.

The beneficial effects of the present invention are that the present invention proposes a method for synchronously testing the vibration of the runner and the outer wall of a through-flow hydraulic machine, which can be applied to the synchronous testing of the vibration of the runner and the outer wall in the model test of the through-flow hydraulic machine , It is also suitable for the vibration synchronization test of the runner and the outer wall of the through-flow hydraulic machinery in large-scale engineering applications. This method does not affect the normal operation of the through-flow hydraulic machinery at all during the measurement process, and can realize the simultaneous measurement of the vibration of the runner and the vibration of the outer wall, with obvious advantages.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a through-flow hydraulic machine in a synchronous testing method of a through-flow hydraulic machine runner and outer wall vibration of the present invention;

Fig. 2 is a schematic diagram of the transparent glass window on the runner chamber during the test engineering application of the synchronous testing method of the runner and the outer wall vibration of the through-flow hydraulic machinery;

Fig. 3 is a synchronous testing method of the vibration of a through-flow hydraulic machinery runner and the outer wall of the present invention, and a schematic diagram of the placement of the laser vibrometer when testing the model of the through-flow hydraulic machinery;

Fig. 4 is a synchronous test method for the vibration of a through-flow hydraulic machinery runner and the outer wall of the present invention, and a schematic diagram of the placement of the laser vibrometer when testing the through-flow hydraulic machinery in engineering applications;

Fig. 5 is a schematic diagram of the connection of related equipment of the test system in a synchronous test method of a through-flow hydraulic mechanical runner and outer wall vibration of the present invention;

In the figure, 1. Inlet pipe, 2. Guide vane, 3. Runner blade, 4. Runner discharge cone, 5. Runner chamber, 6. Draft pipe, 7. Circular window, 8. Laser vibrometer , 9. Rotary photoelectric encoder, 10. Extended shaft, 11. Multi-channel synchronous digital signal acquisition device, 12. Piezoelectric vibration speed sensor, 13. Computer.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The present invention is a synchronous test method for the vibration of a through-flow hydraulic machinery runner and outer wall. The required hardware equipment includes but not limited to: a laser vibrometer based on the Doppler laser principle (the laser is required to be a visible laser with an energy less than 1mW) And the effective working distance of the laser is 0.2 meters to 30 meters), piezoelectric piezoelectric vibration speed sensor, rotary photoelectric encoder and multi-channel (channel number ≥ 8) synchronous digital signal collector. Among them, the sampling frequency of the multi-channel synchronous digital signal collector is adjustable within the range of 50Hz to 128kHz, supports IEPE (ICP) type sensors, and can transmit the collected data to the computer through the USB data transmission cable.

Specifically include the following steps:

Step 1, the structure of the tubular hydraulic machine is shown in Figure 1, including the water inlet pipe 1, the guide vane 2, the runner blade 3, the runner discharge cone 4, the runner chamber 5, and the draft tube 6. First determine the application occasion of the test method. If the object to be tested is a through-flow hydraulic mechanical model in the laboratory, the runner chamber 5 is processed with a high-transparency plexiglass material as a whole;

If the object to be tested is a tubular hydraulic machine in large-scale engineering applications, as shown in Figure 2, it is necessary to machine two Circular window 7 with a circumferential angle of 90°, the radius R of circular window 7 must be greater than 50 mm, and it must be sealed with a highly transparent plexiglass cover to prevent water leakage.

Step 2, arrange the laser vibrometer, photoelectric encoder and piezoelectric vibration velocity sensor.

Step 2.1, if the test object is the model of the through-flow hydraulic machinery in the laboratory, the runner chamber 5 of the through-flow hydraulic machinery has been processed with high-transparency plexiglass material in step 1, so the laser vibrometer 8 is visible The laser can effectively penetrate the runner chamber and focus on the runner water discharge cone 4 . At this time, as shown in Figure 3, the two laser vibrometers 8 are arranged at the same axial position and arranged at a circumferential angle of 90 degrees, so that the direction of the two laser beams can be 90 degrees to shine on the runner to discharge water. On the cone 4, vibration signals in two directions with a circumferential phase of 90 degrees of the runner can be obtained. The radial distance between the two laser vibrometers 8 and the water discharge cone 4 of the runner must be within the range of 0.2 meters to 30 meters.

If the test object is the through-flow hydraulic machinery in large-scale engineering applications, the runner chamber 5 of the through-flow hydraulic machinery has been processed into two circular windows 7 at an angle of 90° in the circumferential direction in step 1. The window 7 is sealed by a high-transparency plexiglass cover, so the laser light can effectively penetrate and focus on the water discharge cone 4 of the runner. At this time, as shown in FIG. 4 , two laser vibrometers 8 with a circumferential angle of 90 degrees are arranged on the same plane as the axial position of the circular window 7 . The circumferential positions of the laser beams of the two laser vibrometers 8 are respectively the same as the circumferential positions of the two circular windows 7, so as to ensure that the two laser beams are respectively injected from the two circular windows 7, and the circumferential phase of the runner is obtained. Vibration signals in two directions at 90 degrees. The radial distance between the two laser vibrometers 8 and the runner water discharge cone 4 must not exceed 30 meters.

Step 2.2, as shown in Figure 5, install the rotary photoelectric encoder 9 on the extension shaft 10 of the tubular hydraulic machine, and lead out the signal output line to the multi-channel synchronous digital signal collector 11; The signal output line of the vibrator 8 is connected to the multi-channel synchronous digital signal collector 11.

Step 2.3, as shown in Figure 5, install a plurality of piezoelectric vibration velocity sensors 12 on the outer walls of the water inlet pipe 1, runner chamber 5 and draft tube 6 according to the specific test location requirements, and the piezoelectric vibration velocity sensors The number of 12 should be less than the number of remaining channels after the multi-channel synchronous digital signal collector 11 is connected with the rotary photoelectric encoder 9 and the two laser vibrometers 8 . The signal output line of the arranged piezoelectric vibration velocity sensor 12 is connected to the multi-channel synchronous digital signal collector 11 , and the output line of the multi-channel synchronous digital signal collector 11 transmits the synchronously collected data to the computer 13 .

Step 3, using the computer 13 to synchronously collect the output signals of the rotary photoelectric encoder 9, the two laser vibrometers 8 and all piezoelectric vibration velocity sensors 12, the measured signals can be analyzed by cross-power spectrum and cross-correlation so that Determine the correlation between signals.

During the test, if the multi-channel synchronous digital signal collector 11 still has redundant channels, it can also be connected to a piezoelectric pressure pulsation sensor that monitors the pressure pulsation inside the flow channel to realize the pressure pulsation, rotation Simultaneous measurement of wheel vibration and outer wall vibration.

Claims (1)

1. A synchronous test method for vibration of a through-flow type hydraulic mechanical runner and an outer wall is characterized in that: the method specifically comprises the following steps:

step 1, processing a runner chamber based on different objects to be tested;

in the step 1:

if the object to be tested is a through-flow hydraulic mechanical model in a laboratory, the whole runner chamber is processed by adopting a high-transparency organic glass material;

when the object to be tested is a through-flow hydraulic machine in engineering application, two circular windows with 90-degree included angles in the circumferential direction need to be processed at the axial positions, aligned with any cross section of a runner drainage cone, on a runner chamber, and the windows are sealed by high-transparency organic glass covers; the radius R of the window is larger than 50mm;

step 2, arranging a laser vibrometer, a photoelectric encoder and a piezoelectric vibration velocity sensor according to the test object selected in the step 1;

the specific process of the step 2 is as follows:

step 2.1, when a test object is a through-flow hydraulic mechanical model in a laboratory, and a through-flow hydraulic mechanical runner chamber is processed by adopting a high-transparency organic glass material in the step 1, so that visible laser of laser vibration testers can effectively penetrate through the runner chamber and focus on a runner drainage cone, at the moment, two laser vibration testers are arranged at the same axial position and are arranged according to a circumferential included angle of 90 degrees, so that the directions of two beams of laser can be 90 degrees and irradiate on the runner drainage cone, and vibration signals in two directions with 90-degree circumferential phases of the runner can be obtained;

when a test object is a through-flow hydraulic machine in engineering application, two circular windows with an included angle of 90 degrees in the circumferential direction are processed in a through-flow hydraulic machine runner chamber in the step 1, and the two circular windows are sealed by a high-transparency organic glass cover, so that laser can effectively penetrate through and focus on a runner drain cone, at the moment, two laser vibration testers with the included angle of 90 degrees in the circumferential direction are arranged on a plane with the same axial position as the circular windows, the circumferential positions of laser beams of the two laser vibration testers are respectively the same as the circumferential positions of the two circular windows, and therefore two beams of laser are ensured to be respectively emitted from the two circular windows, and vibration signals in two directions with the phase of 90 degrees in the circumferential direction of the runner are obtained;

in the step 2.1, when a test object is a through-flow type hydraulic mechanical model in a laboratory, the radial distance between the two laser vibration testers and the runner drainage cone must be within the range of 0.2-30 meters;

when the test object is a through-flow hydraulic machine in engineering application, the radial distance between the two laser vibration meters and the runner drain cone is not more than 30 meters;

step 2.2, a rotary photoelectric encoder is arranged on an extension shaft of the through-flow hydraulic machine, and a signal output line is led out to be connected to a multichannel synchronous digital signal collector; connecting signal output lines of the two laser vibration measuring instruments to a multi-channel synchronous digital signal collector;

2.3, according to specific test position requirements, mounting a plurality of piezoelectric vibration speed sensors on the outer wall surfaces of the water inlet pipe, the runner chamber and the tail water pipe, connecting signal output lines of the arranged piezoelectric vibration speed sensors into a multi-channel synchronous digital signal collector, and transmitting synchronously collected data to a computer by the output lines of the multi-channel synchronous digital signal collector;

in the step 2.3, the number of the piezoelectric vibration speed sensors is less than the number of the channels left after the multichannel synchronous digital signal collector is connected with the rotary photoelectric encoder and the two laser vibration meters;

step 3, synchronously acquiring output signals of the rotary photoelectric encoder, the two laser vibration meters and all piezoelectric vibration speed sensors by adopting a computer, and performing cross-power spectrum analysis and cross-correlation analysis on the measured signals so as to determine the association relation among the signals;

in the testing process, if the multi-channel synchronous digital signal collector still has redundant channels, a piezoelectric pressure pulsation sensor for monitoring pressure pulsation in the flow channel can be accessed, and synchronous measurement of pressure pulsation, runner vibration and outer wall surface vibration in the flow channel of the through-flow hydraulic machinery is realized.

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