JP2013083568A - Blade vibration measuring device - Google Patents

Abstract

Instead of measuring the passage timing of a blade, the time and cost required for the measurement are reduced by directly measuring the displacement of the blade in the rotational axis direction with a response frequency of the order of several hundred kHz.
A plurality of non-contact displacement gauges 3a to 3d that are arranged in a circumferential direction of a turbine rotor blade and measure displacement in a rotation axis direction and output a displacement measurement signal, and a blade tip position whose tip position is identified based on the displacement measurement signal Blade tip position identification devices 4a to 4d that output identification signals, blade vibration calculation devices 5a to 5d that calculate vibration amplitudes and vibration frequencies based on blade tip position identification signals, and vibration mode orders are identified based on vibration amplitudes and vibration frequencies. A vibration mode identification device 6 is provided, and the blade tip position identification device performs curve fitting on the displacement of a plurality of measurement points to obtain a curve, and identifies the tip position from the peak position.
[Selection] Figure 1

Description

  The present invention relates to a blade vibration measuring apparatus for measuring vibrations generated in moving blades of various turbines.

  In the design and development and manufacture of various turbines such as steam turbines and gas turbines, it is necessary to measure vibrations generated in turbine blades in order to improve performance, prevent accidents and ensure reliability.

  In the conventional device for measuring the vibration of the blade, as in the devices described in Patent Documents 1 and 2 below, the passage timing of the blade is measured using a proximity sensor, and the vibration is obtained based on the time difference of the passage timing. The method was used.

  However, in the conventional blade vibration measuring device described above, it is necessary to measure the passage timing of the blade with high accuracy by a high sampling frequency of several hundred MHz or more. Therefore, it is necessary to prepare a data acquisition device having a high sampling frequency and a high time resolution.

  In addition, in order to obtain high time measurement accuracy, it is necessary to pay attention not only to the performance of the acquisition device but also to the transmission time of the measurement signal, and the measured phase difference (time difference) must be converted into displacement. There wasn't. Therefore, there is a problem that much time and cost are required for measurement preparation and measurement data analysis.

  On the other hand, a method of directly measuring blade vibration using a non-contact displacement meter instead of a proximity sensor is also described in Patent Document 3 below.

  Since this method performs measurement at a sampling frequency of about several hundred kHz, the time resolution required for the data acquisition device is relatively low, and preparation of the measurement system and data analysis are relatively easy.

  However, when measuring large rotor blades such as the last stage blades such as steam turbines, sampling cannot catch up with the rotation speed of the blades, and it is impossible to capture displacement at a fixed position, so blade vibration can be measured with high accuracy. It was difficult to do.

Japanese Patent No. 3129406 Japanese Patent No. 3530474 JP 2003-177059 A

  As described above, a device that measures blade vibration in a non-contact manner measures the blade passage timing at a high sampling frequency of several hundred MHz or more and converts the measured phase difference into displacement when a proximity sensor is used. There was a need to do. Therefore, there is a problem that much time and cost are required for measurement preparation and measurement data analysis.

  When measuring the displacement directly, the response frequency of the non-contact displacement meter used is about several hundred kHz at the maximum, making it difficult to accurately measure the displacement at a fixed position of the blade rotating at high speed. There was a problem that it was difficult to measure blade vibration with high accuracy.

  In view of the above circumstances, the present invention reduces the time and cost required for measurement by directly measuring the displacement of the blade in the rotational axis direction with a response frequency on the order of several hundred kHz instead of measuring the passage timing of the blade. An object of the present invention is to provide a blade vibration measuring apparatus capable of performing the above.

A blade vibration measuring apparatus according to an aspect of the present invention is provided.
A non-contact displacement meter that is arranged in a plurality along the circumferential direction of the turbine rotor blade and that measures a displacement in the rotational axis direction of the turbine rotor blade and outputs a displacement measurement signal;
A plurality of non-contact displacement gauges are provided corresponding to the displacement measurement signals output from the non-contact displacement gauges, and the non-contact displacement gauges and the tip positions of the turbine blades A blade tip position identification device that outputs a blade tip position identification signal that identifies the tip position based on each distance between;
A plurality of blade tip position identification devices are provided corresponding to the blade tip position identification device, the blade tip position identification signal output from the blade tip position identification device is given, and from the non-contact displacement meter to the tip position of the turbine blade A blade vibration calculation device for calculating a vibration amplitude and a vibration frequency of the turbine rotor blade based on a temporal change in distance;
A vibration mode identification device for identifying the vibration mode order of the turbine blade based on the vibration amplitude and vibration frequency of the turbine blade output from each of the blade vibration calculation devices;
With
Each of the blade tip position identification devices performs curve fitting on the displacement at a plurality of measurement points included in the given displacement measurement signal and interpolates between them to obtain a curve, and the turbine motion is determined from the peak position of the curve. It is characterized by identifying the tip position of the wing.

Further, the blade vibration measuring device according to one aspect of the present invention,
A rotational speed adjusting device for changing the rotational speed of the turbine blade,
A rotation synchronization pulse generating device that outputs a rotation synchronization pulse every time each blade of the turbine blade passes a predetermined position;
A non-contact displacement meter that is arranged in a plurality along the circumferential direction of the turbine blade and that measures the displacement in the rotation axis direction of the turbine blade at the time when the rotation synchronization pulse is given and outputs a displacement measurement signal When,
A plurality of the non-contact displacement gauges are provided corresponding to the displacement measurement signals output from the non-contact displacement gauges, and the rotation synchronization pulses in the non-contact displacement gauges and the turbine blades are provided. A blade identical point measuring device that outputs the same point displacement signal indicating the respective distances between the same point corresponding to
The blade reference rearrangement device that is provided with the same point measurement signal output from the blade identical point measurement device and outputs a time series displacement signal rearranged corresponding to each blade of the turbine blade,
FET arithmetic unit which is given the time series displacement signal output from the wing reference rearrangement device, performs a fast Fourier transform and outputs a fast Fourier transform result signal, and
A Campbell diagram creation device that is provided with the fast Fourier transform result signal output from the FET arithmetic unit, creates a Campbell diagram and evaluates vibration characteristics of the turbine blade,
It is characterized by providing.

  According to the blade vibration measuring device of the present invention, it is possible to reduce the time and cost required for measurement by directly measuring the displacement of the blade in the rotation axis direction at a response frequency on the order of several hundred kHz with high accuracy. .

It is the block diagram and front view which show the structure of the blade vibration measuring device by the 1st Embodiment of this invention. It is the block diagram and side view which show the structure of the blade vibration measuring device by the 1st Embodiment. It is explanatory drawing which shows the method of identifying a blade tip position in the said 1st Embodiment. It is explanatory drawing which shows the method of calculating a blade vibration amplitude and vibration frequency in the said 1st Embodiment. It is explanatory drawing which showed the method of performing curve fitting with respect to the several measurement point of the output signal of a non-contact-type displacement meter in the said 1st Embodiment. It is the block diagram and front view which show the structure of the blade vibration measuring device by the 2nd Embodiment of this invention. It is the block diagram and side view which show the structure of the blade vibration measuring device by the 2nd embodiment. In the 2nd Embodiment, it is explanatory drawing which showed the method of rearranging a blade tip position for every blade and performing curve fitting. It is explanatory drawing which shows the structure of the blade vibration measuring device by the 3rd Embodiment of this invention. It is explanatory drawing which showed the method of measuring the displacement in the same point of a turbine rotor blade using a rotation synchronous pulse in the said 3rd Embodiment. It is a graph which shows the relationship of the vibration amplitude with respect to the frequency obtained by performing a fast Fourier transform to the displacement signal in the same point of the turbine rotor blade 2 in the said 3rd Embodiment. FIG. 12 is a Campbell diagram in which the result of FIG. 11 is acquired for each rotation speed of the turbine rotor blade 2 and plotted with the horizontal axis representing the rotation speed and the vertical axis representing the vibration frequency in the third embodiment. It is explanatory drawing which shows the structure of the blade vibration measuring device by the 4th Embodiment of this invention. It is a graph which shows the displacement at the time of secondary resonance mode generation | occurrence | production which can be measured with the blade vibration measuring device by the same 4th Embodiment. It is a graph which shows the displacement at the time of 4th resonance mode generation | occurrence | production which can be measured with the blade vibration measuring device by the 4th embodiment. It is a graph which shows the displacement at the time of generation | occurrence | production of the 8th resonance mode which can be measured with the blade vibration measuring device by the same 4th Embodiment.

  Hereinafter, a blade vibration measuring device according to an embodiment of the present invention will be described with reference to the drawings.

(1) 1st Embodiment As a figure which shows the structure of the 1st Embodiment of this invention, the front view of the turbine rotor blade 2 is shown in FIG. 1, and a side view is shown in FIG.

  In order to measure the displacement in the rotational axis direction of the turbine rotor blade 2 attached to the rotary shaft 1, a plurality of non-contact type displacement meters 3a are arranged on the same radius at predetermined intervals along the circumferential direction of the turbine rotor blade 2. 3b, 3c, 3d are arranged.

  Displacement measurement signals output from the respective non-contact displacement gauges 3a, 3b, 3c, and 3d are input to the corresponding blade tip position identification devices 4a, 4b, 4c, and 4d, and the tip position of the turbine blade 2 is identified. Then, a blade tip position identification signal indicating the result is output.

  The blade tip position identification signal is given to the corresponding blade vibration calculation devices 5a, 5b, 5c, and 5d, and the vibration amplitude and vibration frequency of the turbine rotor blade 2 are calculated and output to the vibration mode identification device 6.

  In the vibration mode identification device 6, the vibration mode order is obtained based on the vibration amplitude and vibration frequency at the installation positions of the non-contact displacement meters 3a, 3b, 3c, and 3d.

  Here, a method for identifying the blade tip position in the blade tip position identification devices 4a, 4b, 4c, and 4d will be described with reference to FIG.

  As shown in FIG. 3A, the blade row of the turbine rotor blade 2 rotates and moves in the direction indicated by the arrow. Of the non-contact displacement gauges 3a, 3b, 3c, and 3d, as an example, the blade row of the turbine rotor blade 2 passes in front of the non-contact displacement gauge 3a. A displacement measurement signal having a voltage waveform as shown in b) is output. Here, the detection position of the turbine rotor blade 2 by the non-contact displacement meter 3a indicated by the square in FIG. 3A corresponds to the position indicated by the square on the output voltage waveform in FIG. 3B. .

  Further, the tip position of the turbine rotor blade 2 indicated by dots 2a1, 2a2, and 2a3 in FIG. 3A is the lowest end of the output voltage waveform indicated by dots 101, 102, and 103 in FIG. 3B. Corresponds to the peak value.

  A method for calculating the vibration amplitude and vibration frequency of the turbine blade 2 by the blade vibration calculation device 5 will be described with reference to FIG.

  As shown in FIG. 4A, when vibration occurs in the turbine rotor blade 2, it does not contact the tip position of the turbine rotor blade 2 indicated by dots 2a1, 2a2, 2a3, 2a4, 2a5, 2a6, 2a7. The distance X to the mold displacement meter 3 varies. This variation is a variation in the peak value at the lowest end of the output voltage waveform indicated by the dots 101, 102, 103, 104, 105, 106, 107 described with reference to FIG. Therefore, the voltage corresponding to the blade tip position output from the blade tip position identification device 4a is applied to the blade tip position and the non-contact displacement meter 3a in the blade vibration calculation device 5a as shown in FIG. Is converted into a relative distance between the two, and the obtained relative distance is recorded in time series. From the time-series data recorded in this way, the vibration amplitude and vibration frequency of the turbine rotor blade 2 can be calculated.

  Furthermore, the first embodiment is characterized in that curve fitting is performed when the tip position of the turbine rotor blade 2 is identified in each of the blade tip position identification devices 4a, 4b, 4c, and 4d.

  In FIG. 5A, the distance to the turbine rotor blade 2 is measured by, for example, the non-contact displacement meter 3a among the non-contact displacement meters 3a, 3b, 3c, 3d, 3e, and 3f. When the turbine blade 2 passes in front of the non-contact displacement gauge 3a, the distance to the discontinuous blade measurement positions 2a11, 2a12, 2a13, 2a14, 2a15 corresponding to the sampling timing in the turbine blade 2 is measured. The displacement measurement signal is output.

  When such a displacement measurement signal is input to the blade tip position identification device 4a, the measurement values at the discontinuous blade measurement positions 2a11, 2a12, 2a13, 2a14, and 2a15 are sampled and stored.

  The measured values at the respective blade measurement positions 2a11, 2a12, 2a13, 2a14, 2a15 are indicated by dotted lines by curve fitting using, for example, a least square method so as to interpolate between them. A curve S like this is obtained. From the peak value in this curve S, the blade tip estimated position 2a14 is obtained.

  When the rotational speed of the turbine rotor blade 2 becomes high, it becomes difficult to identify the blade tip position using a non-contact displacement meter. Therefore, the voltage values of the displacement measurement signal from the non-contact displacement meter at a plurality of measurement positions near the blade tip are sampled and acquired, and curve fitting is performed on these values. By identifying the peak value of the curve S thus obtained as the blade tip position, the accuracy of blade tip position identification can be improved. The higher the sampling frequency, the higher the accuracy of blade tip position identification. However, since the amount of processing increases, the processing time and cost may be taken into consideration, and the frequency may be set to, for example, about several hundred kHz.

  According to the first embodiment, instead of measuring the passage timing of the blade, the time and cost required for measurement are measured by directly measuring the displacement of the blade in the rotational axis direction with a response frequency of the order of several hundred kHz. Can be reduced.

  When curve fitting is performed on the measured value, data indicating the shape of the turbine rotor blade 2 is stored in advance in a storage device (not shown), and the curve fitting is performed by using this data to perform turbine motion. The curved shape of the blade 2 can be obtained with high accuracy. Furthermore, although the turbine rotor blade 2 changes depending on the operation state, storing the shape data in each operation state makes it possible to obtain the curve shape with higher accuracy and identify the blade tip position.

(2) Second Embodiment As diagrams showing the configuration of the second embodiment of the present invention, FIG. 6 is a front view of the turbine rotor blade 2, and FIG. 7 is a side view thereof.

  The second embodiment is different from the configuration of the first embodiment in that a rotation speed adjusting device 8 for changing the rotation speed of the rotary shaft 1 is further provided. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  When the rotary shaft 1 is rotated at a predetermined rotational speed, the blade tip position identification devices 4a, 4b, 4c, and 4d identify the blade tip position of the turbine rotor blade 2, and output a blade tip position identification signal. The As in the first embodiment, the blade tip position identification signal is given to the corresponding blade vibration calculation devices 5a, 5b, 5c, and 5d, and the vibration amplitude and vibration frequency of the turbine rotor blade 2 are calculated and the vibration mode is calculated. It is output to the identification device 6.

  The vibration mode identification device 6 is provided with vibration amplitude and vibration frequency from the blade vibration calculation devices 5a, 5b, 5c, and 5d, and displacement measurement signals output from the non-contact displacement meters 3a, 3b, 3c, and 3d. Given.

  In the vibration mode identification device 6, data indicating the blade tip position included in the displacement measurement signal is rearranged for each blade in the turbine rotor blade 2 to determine the resonance mode order. Specifically, displacement measurement values obtained by the blades sequentially passing in front of the non-contact displacement meters 3a, 3b, 3c, and 3d are collected for each blade.

  When the rotational speed of the rotating shaft 1 is changed by the rotational speed adjusting device 8 and a resonance phenomenon occurs, a graph in which the displacement regularly changes during one rotation of one blade as shown in FIG. 8 is obtained. A curve in which the displacement changes is approximated to a sine curve. The vibration mode identification device 6 performs curve fitting on the discontinuous displacement measurement values obtained by sampling, and the resonance mode is identified.

  In this way, by performing curve fitting of discontinuous displacement measurement values in a resonance state to a sine curve, the number of non-contact type displacement meters 3 can be reduced, so that the cost required for measurement can be reduced.

  According to the second embodiment, as in the first embodiment, instead of measuring the passage timing of the blade, the displacement in the direction of the rotation axis of the blade is directly directly measured with a response frequency on the order of several hundred kHz. By measuring, the time and cost required for measurement can be reduced, and the number of non-contact displacement gauges 3 can be reduced by curve fitting the discontinuous displacement measurement values at the time of resonance to a sine curve. Can contribute.

(3) Third Embodiment A blade vibration measuring apparatus according to a third embodiment of the present invention will be described with reference to FIG.

  Sixteen non-contact displacement meters 3a, 3b, 3c,..., 3p are arranged along the circumferential direction of the turbine rotor blade 2.

  Further, a rotation synchronization pulse generator 11 is installed at a predetermined position of the turbine rotor blade 2, and a rotation synchronization pulse is generated every time any blade of the turbine rotor blade 2 passes the predetermined position. The contact displacement meters 3a, 3b, 3c,.

  Thereby, in the non-contact type displacement meters 3a, 3b, 3c,..., 3p, a displacement measurement signal indicating the distance (displacement) to the rotating turbine rotor blade 2 at the time when the rotation synchronization pulse is given is generated and output. Is done.

  The output displacement measurement signals are given to the same number of blade identical point measuring devices 12a, 12b, 12c,..., 12p corresponding to the non-contact displacement meters 3a, 3b, 3c,. In the blade identical point measuring devices 12a, 12b, 12c,..., 12p, the distance to the same point of the rotating turbine blade 2 is measured based on the displacement measurement signal, and the same point displacement signal is output. In this way, the same point displacement signals are output from the blade identical point measuring devices 12a, 12b, 12c,..., 12p, respectively, and are given to the blade reference rearranging device 13.

  In the blade reference rearrangement device 13, the given 16 identical point displacement signals are rearranged corresponding to each blade of the turbine rotor blade 2 and output as a time-series displacement signal, to the FET arithmetic device 14. Given.

  In the FET arithmetic unit 14, fast Fourier transform is performed on the time-series displacement signals rearranged corresponding to each blade, and the obtained result is given to the Campbell diagram creation device 15 as a fast Fourier transform result signal. .

  The Campbell diagram creation device 15 creates a Campbell diagram as described later using FIG. 12 based on the fast Fourier transform result signal, evaluates the vibration characteristics of the turbine rotor blade 2, and uses the result as an evaluation result signal. Output to the outside.

  As shown in FIG. 10A, it is necessary to measure the displacement of the same point 2a1, 2a2, 2a3 of each blade in the turbine rotor blade 2. Therefore, by using the rotation synchronization pulse as shown in FIG. 10B, the same point 2a1 of each blade in the displacement measurement signal output from the non-contact type displacement meters 3a, 3b, 3c,. The displacements at the positions 101, 102, 103 corresponding to 2a2, 2a3 are specified. Thereby, in each wing | blade same point measuring apparatus 12a-12p, the displacement of the same point of each wing | blade is measured.

  Then, the rotation speed adjustment device 8 performs measurement while gradually increasing the rotation speed, and obtains the resonance point and the resonance mode.

  In general, 2 * N sensors are required to measure N (N is a natural number) order resonance mode. In the third embodiment, since 16 non-contact displacement meters 3a to 3p are used, it is possible to capture up to the eighth-order resonance mode.

  FIG. 11 shows a frequency obtained by subjecting a displacement measurement signal at the same point of the turbine rotor blade 2 generated by the blade reference rearrangement device 13 to a fast Fourier transform by the FFT operation device 14 at a predetermined rotational speed. The relationship of the vibration amplitude with respect to is shown. The resonance point is a point in time when the vibration amplitude becomes maximum, and the frequency at this time becomes the resonance frequency.

  Such a fast Fourier transform is performed for each rotation speed of the turbine rotor blade 2. The obtained results are plotted on a graph with the horizontal axis representing the number of revolutions and the vertical axis representing the vibration frequency, as shown in the Campbell diagram of FIG.

  In this Campbell diagram, straight lines connecting predetermined integer multiples of the respective rotation frequencies are shown. For example, a straight line of 1H (H is a natural number) is a straight line connecting a frequency of 1 times the rotational frequency, a straight line of 2H is a straight line connecting a frequency twice as high as the rotational frequency,. It is a straight line connecting 8 times the frequency.

  Also, the size of the white circles shown in this Campbell diagram is proportional to the magnitude of the vibration amplitude. For this reason, the size of a set of white circles arranged in a line in the vertical direction in FIG. 12 corresponds to the magnitude of each vibration amplitude from 1H to 8H at a predetermined number of revolutions. This corresponds to the vibration amplitude at a predetermined rotational speed shown in the graph.

  In the Campbell diagram created by the Campbell diagram creation device 15 in this way, the vibration frequency at which the vibration amplitude increases regardless of the rotational speed is estimated as the resonance frequency at the resonance point.

  According to the third embodiment, as in the first embodiment, instead of measuring the passage timing of the blade, the displacement of the blade in the rotational axis direction can be directly measured accurately with a response frequency of the order of several hundred kHz. By measuring, it is possible to reduce the time and cost required for measurement, and the resonance frequency can be obtained by creating a Campbell diagram.

(4) Fourth Embodiment A blade vibration measuring apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS.

  The fourth embodiment has the configuration shown in FIG. A first non-contact displacement meter 3a is arranged along the circumferential direction of the turbine rotor blade 2, and a second non-contact displacement meter 3a is spaced from the non-contact displacement meter 3a by an angle of 22.5 degrees. A displacement meter 3b is disposed, a third non-contact displacement meter 3c is disposed at an interval of 45 degrees from the first non-contact displacement meter 3a, and further 90 degrees from the first non-contact displacement meter 3a. A fourth non-contact type displacement meter 3d is arranged with an interval of.

  Displacement measurement signals output from the non-contact displacement gauges 3a, 3b, 3c, and 3d are given to the blade tip position identification devices 4a, 4b, 4c, and 4d provided corresponding to the displacement measurement signals. The position is identified, and the result is output as a blade tip position identification signal and provided to the blade vibration calculation devices 5a, 5b, 5c, and 5d.

  In the blade vibration calculation devices 5a, 5b, 5c and 5d, the vibration amplitude and vibration frequency of the turbine rotor blade 2 are calculated based on the blade tip position identification signal, and the result is given to the vibration mode identification device 6 as a blade vibration signal. .

  In the vibration mode identification device 6, the vibration mode is identified based on the vibration amplitude and vibration frequency at the position where the non-contact displacement meters 3 a to 3 d are arranged.

  In FIG. 14, when the secondary resonance mode occurs, the measurement is performed by the non-contact displacement meters 3 a to 3 d that are arranged in order along the circumferential direction of the turbine rotor blade 2 with the above-described angular intervals. The displacement is indicated by a black circle. Similarly, FIG. 15 shows the displacements measured by the non-contact displacement meters 3a to 3d when the fourth-order resonance mode is generated and FIG. 16 is the eighth-order resonance mode.

  In the secondary resonance mode shown in FIG. 14, the displacement of the measurement points 201, 202, and 203 corresponding to the arrangement positions of the non-contact displacement meters 3a to 3d is on the plus side, and the displacement of the measurement point 204 is on the minus side. To do.

  In the fourth-order resonance mode shown in FIG. 15, the displacements of the measurement points 201 and 202 corresponding to the arrangement positions of the non-contact displacement meters 3a to 3d are positive, the displacement of the measurement point 203 is negative, and further the measurement points The displacement of 204 is located on the plus side.

  In the eighth-order resonance mode shown in FIG. 16, the displacement of the measurement point 201 corresponding to the arrangement position of the non-contact displacement meters 3 a to 3 d is positive, the displacement of the measurement point 202 is negative, and the displacement of the measurement point 203. Is located on the plus side, and the displacement of the measurement point 204 is located on the plus side.

  In this way, it is possible to easily determine which resonance mode has occurred.

  Here, in order to capture up to the eighth-order resonance mode, the minimum interval of the arrangement of the non-contact displacement meters 3a to 3d is 22.5 degrees, that is, the half cycle of the eighth-order vibration mode. By arranging them at such intervals, nodes in the eighth-order vibration mode can always be captured.

  Furthermore, by arranging the non-contact type displacement meter at an even multiple of this minimum interval of 22.5 degrees, it is possible to capture nodes of lower order vibration modes.

  Therefore, according to the fourth embodiment, compared with the case where non-contact displacement meters are arranged in the circumferential direction at equal intervals, the number of non-contact displacement meters is reduced, and the order of the resonance mode is improved. Since it can be understood well, it is possible to contribute to cost reduction.

  Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the technical scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the technical scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

1 Rotating shaft 2 Turbine blades 3, 3a, 3b, 3c, 3d, 3e, 3f Non-contact displacement gauges 4, 4a, 4b, 4c, 4d, 4e, 4f Blade tip position identification devices 5, 5a, 5b, 5c 5d, 5e, 5f Blade vibration calculation device 6 Vibration mode identification device 7 Rotating jig 8 Rotational speed adjustment device 9 Eddy current displacement meter 10 Rotation reference 11 Rotation synchronization pulse generation device 12 Blade identities measurement device 13 Blade reference rearrangement device 14 FFT processor 15 Campbell diagram creation device

Claims (4)

A non-contact displacement meter that is arranged in a plurality along the circumferential direction of the turbine rotor blade and that measures a displacement in the rotational axis direction of the turbine rotor blade and outputs a displacement measurement signal;
A plurality of non-contact displacement gauges are provided corresponding to the displacement measurement signals output from the non-contact displacement gauges, and the non-contact displacement gauges and the tip positions of the turbine blades A blade tip position identification device that outputs a blade tip position identification signal that identifies the tip position based on each distance between;
A plurality of blade tip position identification devices are provided corresponding to the blade tip position identification device, the blade tip position identification signal output from the blade tip position identification device is given, and from the non-contact displacement meter to the tip position of the turbine blade A blade vibration calculation device for calculating a vibration amplitude and a vibration frequency of the turbine rotor blade based on a temporal change in distance;
A vibration mode identification device for identifying the vibration mode order of the turbine blade based on the vibration amplitude and vibration frequency of the turbine blade output from each of the blade vibration calculation devices;
With
Each of the blade tip position identification devices performs curve fitting on the displacement at a plurality of measurement points included in the given displacement measurement signal and interpolates between them to obtain a curve, and the turbine motion is determined from the peak position of the curve. A blade vibration measuring device characterized by identifying the tip position of a blade. A rotation speed adjusting device for changing the rotation speed of the turbine rotor blade;
When the rotational speed of the turbine blade is changed by the rotational speed adjusting device and a resonance phenomenon occurs in the turbine blade, the blade tip position identification signal identified by the blade tip position identifying device is used as the vibration mode identification. The blade vibration measuring device according to claim 1, wherein the device sorts and collects each blade of the turbine blade and identifies the resonance mode order. The plurality of non-contact displacement meters arranged along the circumferential direction of the turbine rotor blade includes at least first, second, third, and fourth non-contact displacement meters,
The second non-contact displacement meter is disposed at a position spaced from the first non-contact displacement meter by a half cycle of a resonance mode of a predetermined order, and the third non-contact displacement meter Is disposed at a position that is twice the interval with respect to the first non-contact displacement meter, and the fourth non-contact displacement meter is located with respect to the first non-contact displacement meter. The blade vibration measuring device according to claim 1, wherein the blade vibration measuring device is arranged at a position having an interval four times the interval. A rotational speed adjusting device for changing the rotational speed of the turbine blade,
A rotation synchronization pulse generating device that outputs a rotation synchronization pulse every time each blade of the turbine blade passes a predetermined position;
A non-contact displacement meter that is arranged in a plurality along the circumferential direction of the turbine blade and that measures the displacement in the rotation axis direction of the turbine blade at the time when the rotation synchronization pulse is given and outputs a displacement measurement signal When,
A plurality of the non-contact displacement gauges are provided corresponding to the displacement measurement signals output from the non-contact displacement gauges, and the rotation synchronization pulses in the non-contact displacement gauges and the turbine blades are provided. A blade identical point measuring device that outputs the same point displacement signal indicating the respective distances between the same point corresponding to
The blade reference rearrangement device that is provided with the same point measurement signal output from the blade identical point measurement device and outputs a time series displacement signal rearranged corresponding to each blade of the turbine blade,
FET arithmetic unit which is given the time series displacement signal output from the wing reference rearrangement device, performs a fast Fourier transform and outputs a fast Fourier transform result signal, and
A Campbell diagram creation device that is provided with the fast Fourier transform result signal output from the FET arithmetic unit, creates a Campbell diagram and evaluates vibration characteristics of the turbine blade,
A blade vibration measuring device comprising:

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