JPH112586A - Blade shaker used in rotational vibration test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable efficient rotational vibration test by controlling the opening and closing of a solenoid valve by using a dividing signal of a pulse signal corresponding to the rotation of a rotor to intermittently blow air to a moving blade. SOLUTION: When a turbine rotor 1 is rotated, output signals are input to a rotation detector 12 by a rotation detecting probe 11 and a reflection tape 10, and the rotation detector 12 outputs pulse signals of the number corresponding to the revolutions of the turbine rotor 1. The pulse signals are input to a divider 13, and the divider signal operates a solenoid valve 7 through a high speed power amplifier 14 and a relay 15. In the case the dividing signal has duty ratio of 50%, for example, the moving blade 2 is intermittently shaked in synchronism with the rotation by the opening operation for five turns of the solenoid valve 7 and the subsequent closing operation for five turns. Accordingly, when the opening of the valve 4 is the same, the quantity of air blown off by a shaking nozzle 8 is reduced to the half as compared with the case of continuous blow-off operation, so that the quantity of air blown off by the nozzle 8 can be increased by increasing the opening of the valve 4 so as to heighten the shaking force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade vibration device applied to an industrial turbine or the like and used for a rotational vibration test.

[0002]

2. Description of the Related Art Rotary vibration tests of industrial turbines and the like are performed by:
This is performed by blowing air on the moving blades and vibrating them, and a blade vibrating device is used for blowing the air.

A conventional blade vibration device will be described with reference to FIG. FIG. 4 shows a case in which this device is applied to a turbine rotor 1 having a plurality of stages of disks on which approximately 80 to 120 blades 2 are attached at equal intervals in the circumferential direction. The state where the blade vibration device is provided for one disk is shown.

[0004] In the conventional blade vibration device shown in FIG.
It comprises an air source 3, a valve 4, a meter 5, a pipe 6, and a vibrating nozzle 8. At the time of a rotational vibration test, air is supplied from the air source 3 to the vibrating nozzle 8 while adjusting the flow rate by the valve 4. Air is blown from the vibration nozzle 8 to the moving blades 2 of the turbine rotor 1 rotating in the turbine casing which is in a vacuum state, and vibrates the moving blades 2 by disturbing the air flow, so that the primary and secondary Mode vibration was generated.

In the rotational vibration test, a sensor 16 is disposed at a position facing the vibrating nozzle 8 with the moving blade 2 interposed therebetween and fixed to a partition plate 17 provided at a stationary portion of the turbine casing. The thermometer 18 is used.
While monitoring the interior temperature to be equal to or lower than the allowable upper limit value by using the valve 8, the amount of air is adjusted by the valve 4, and the vibration of the tip of the rotor blade 2 caused by blowing the air from the vibration nozzle 8 is measured. This is done by:

[0006] During the above-mentioned test, air is blown out from the vibrating nozzle 8, which may reduce the degree of vacuum in the turbine cabin. This is prevented by operating the vacuum pump constantly.

[0007]

The conventional blade vibrating apparatus for a turbine rotor blade has the following problems.

(1) The turbine rotor is 3000 to 360
When air is blown from the vibrating nozzle to the moving blade during high-speed rotation at a rotation speed of 0 rpm, the temperature inside the vacuum chamber rises considerably due to frictional heat between the moving blade and air. In this case, it is necessary to adjust the amount of air so that the temperature is within the allowable upper limit. However, since the blade cannot be excited with a small amount of air, it takes time to adjust the amount of air.

(2) Since vibration in the predetermined mode cannot be confirmed, when the position of the vibrating nozzle is to be changed in the radial direction, it is necessary to replace the entire nozzle, which consumes work time and labor.

The present invention solves the above-mentioned problems, and can increase the exciting force without increasing the total amount of air, and can easily adjust the position of the exciting nozzle, thereby improving the efficiency. It is an object of the present invention to realize a blade vibration device capable of performing a typical rotational vibration test.

[0011]

[Means for Solving the Problems]

(1) The present invention includes a vibrating nozzle that blows air to a moving blade provided on a rotor, and an air source connected to the nozzle via a pipe, and blows air to a rotating moving blade. In a blade vibration device used for a rotational vibration test, an electromagnetic valve provided in the pipe, rotation detection means for detecting rotation of the rotor and outputting a pulse signal corresponding to the rotation,
And an electromagnetic valve driving means for inputting a pulse signal from the rotation detecting means and dividing the frequency, and opening and closing the electromagnetic valve by the divided signal.

In the present invention, a frequency-divided signal having a reduced repetition rate of a pulse signal corresponding to the rotation of the rotor is used. The solenoid valve is opened when a pulse is generated, and closed when the pulse disappears. Blow air onto the bucket.

Therefore, while suppressing the total amount of air blown from the vibrating nozzle to the moving blade, the amount of air blown to the moving blade can be increased, and the temperature inside the vehicle compartment due to frictional heat between the moving blade and air can be increased. It is possible to increase the exciting force on the rotor blade while suppressing the rise.

(2) The present invention includes a vibrating nozzle for blowing air to a moving blade provided on a rotor, and an air source connected to the nozzle via a pipe, so that air is supplied to the rotating moving blade. A blade vibration device used for a rotational vibration test performed by spraying is characterized by including a flexible joint provided between the vibration nozzle and the pipe.

In the present invention, since a flexible joint is provided between the vibrating nozzle and the pipe so that the position of the vibrating nozzle can be easily adjusted, the working time and labor can be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A blade vibration device according to an embodiment of the present invention will be described with reference to FIG. The blade vibration device according to the present embodiment is applied to a turbine having a turbine rotor 1 provided with a plurality of stages of moving blades 2 in the same manner as described in the related art, and a sensor 16 mounted on a partition plate 17. And a thermometer 18 were applied to a rotational vibration test.

Further, similarly to the conventional apparatus, the air source 3,
The apparatus includes a valve 4, a meter 5, a pipe 6, and a vibrating nozzle 8. Since this part is the same as a conventional apparatus, a detailed description thereof will be omitted.

In this embodiment shown in FIG. 1, in the above-mentioned blade vibration device, a reflection tape 10 attached to an end of the above-mentioned rotor 1 is disposed near and opposite to the reflection tape 10. A rotation detector 12 to which the rotation detection probe 11 is connected, a frequency divider 13 to which the rotation detector 12 is connected, a relay 15 to which the frequency divider 13 is connected via a high-speed power amplifier 14, and a relay 15 An electromagnetic valve 7 connected to the pipe 6 and a flexible joint connected between the pipe 6 and the vibration nozzle 8 are provided.

The reflection tape 10, the rotation detecting probe 11, and the rotation detector 12 form a rotation detecting means, and the frequency divider 13, the high-speed power amplifier 14, and the relay 15 form an electromagnetic valve driving means.

In the above, when the turbine rotor 1 rotates, the rotation detecting probe 11 receives the light reflected by the reflection tape 10 and inputs an output signal to the rotation detector 12, and the rotation detector 12 determines the rotation speed of the turbine rotor 1. The number of pulse signals corresponding to is output.

The pulse signal output from the rotation detector 12 is input to a frequency divider 13 which divides the frequency of the pulse signal and inputs the frequency-divided signal to a high-speed power amplifier 14 for amplification. The frequency-divided signal is input to the relay 15 and the relay 15
Actuates the solenoid valve 7 based on this signal.

The operation of the solenoid valve 7 based on the frequency-divided signal will be specifically described with reference to FIG. In addition, FIG.
An example in which 10 rotations of the turbine rotor 1 are divided into one pulse is shown.
Input 0 pulse and output 1 pulse. The frequency division signal has a duty ratio of 50%, and the relay 15 is operated so that the solenoid valve 7 is opened for five rotations and then closed for five rotations.

In this case, since the rotor blades 2 are intermittently vibrated in synchronization with the rotation, if the opening of the valve 4 is the same, the vibrating nozzle 8 blows out as compared with the case of continuously blowing out. The amount of air is reduced by half, the opening degree of the valve 4 is increased, the amount of air blown out from the vibration nozzle 8 is increased, and the vibration force can be increased.

At the time of the above-described turbine rotational vibration test, the rotor blades 2 are largely shaken by a small excitation force, and the excitation nozzle 8 is positioned at a position where the primary and secondary mode vibrations can be reliably confirmed. However, in some cases, the vibration of the secondary mode cannot be actually confirmed at that position.

In this embodiment, since the flexible joint 9 is provided, the fixed position of the vibrating nozzle 8 can be moved by a distance 1 by using the flexible joint 9, and the vibration in the secondary mode can be confirmed. The vibration nozzle 8 can be easily moved to a position where it can be performed.

[0026]

The blade vibration device used in the rotational vibration test according to the present invention comprises a solenoid valve provided in a pipe between a vibration nozzle for blowing air to the rotor blade and an air source, and a rotation valve for rotating the rotor. It is provided with rotation detecting means for detecting and outputting a pulse signal corresponding to the rotation, and electromagnetic valve driving means for inputting and dividing the pulse signal and opening and closing the electromagnetic valve with the divided signal. As a result, it is possible to increase the amount of air when blowing on the rotor blades while suppressing the total amount of air, so that vibrations on the rotor blades are suppressed while suppressing the temperature rise in the vehicle interior due to the frictional heat between the rotor blades and air. The force can be increased, the air amount can be easily adjusted, and an efficient test can be performed.

Further, by providing a flexible joint between the vibrating nozzle and the pipe, the position of the vibrating nozzle can be easily adjusted, so that the working time and labor can be reduced. Become.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a blade vibration device according to an embodiment of the present invention.

FIGS. 2A and 2B are operation explanatory diagrams according to the embodiment, wherein FIG. 2A shows an output signal of a rotation detector, FIG. 2B shows an output signal of a frequency divider,
(C) is an explanatory view of the opening and closing operation of the solenoid valve.

FIG. 3 is an explanatory diagram of a vibration mode of a bucket according to the embodiment.

FIG. 4 is an explanatory view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Turbine rotor 2 Moving blade 3 Air source 4 Valve 5 Meter 6 Pipe 7 Solenoid valve 8 Vibration nozzle 9 Flexible joint 10 Reflective tape 11 Rotation detection probe 12 Rotation detector 13 Divider 14 High-speed power amplifier 15 Relay 16 Sensor 17 Partition Plate 18 thermometer

Claims (2)

[Claims] A rotary vibration is provided by providing a vibrating nozzle for blowing air to a moving blade provided on a rotor, and an air source connected to the nozzle via a pipe, and blowing air to the rotating moving blade. In the blade vibration device used for the test, an electromagnetic valve provided in the pipe, rotation detection means for detecting rotation of the rotor and outputting a pulse signal corresponding to the rotation, and inputting a pulse signal from the rotation detection means And an electromagnetic valve driving means for opening and closing the electromagnetic valve in accordance with the frequency-divided signal. 2. A rotary vibration, comprising: a vibrating nozzle for blowing air to a moving blade provided on a rotor; and an air source connected to the nozzle via a pipe, and blowing air to the rotating moving blade. A blade vibration device used for a rotational vibration test, comprising a flexible joint provided between the vibration nozzle and a pipe.