JP2018173297A - Blade vibration monitoring apparatus, rotation machine system, and blade vibration monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade vibration monitoring apparatus capable of easily grasping an abnormality of a moving blade.SOLUTION: The blade vibration monitoring apparatus for a rotation machine having a pair of journal bearings 9 holding a row of moving blades from the direction of an axis O for supporting a rotating shaft 4 so as to be rotatable around the axis O and a pair of bearing stands 15 supporting the respective bearings 9, comprises: a plurality of acceleration sensors 40A and 40B arranged to be spaced in the direction of the axis O in the rotation machine; and a main portion 50 of the blade vibration monitoring apparatus having a level difference calculation unit which calculates the difference between the acceleration response levels input from the plurality of acceleration sensors 40A and 40B and a moving blade row specifying unit which specifies a moving blade row 6 having abnormality among the plurality of moving blade rows 6 on the basis of the difference calculated by the level difference calculation unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a blade vibration monitoring device, a rotary machine system, and a blade vibration monitoring method.

  For example, a rotary machine such as a steam turbine or a gas turbine has a rotating shaft and a moving blade row group composed of a plurality of moving blade rows provided on the outer periphery of the rotating shaft. During operation of the rotating machine, the vibration of the rotating blade row is measured. By performing such measurement, it is possible to verify whether or not the vibration characteristics of the rotor blade row are as designed. In addition, it is possible to confirm the change in the vibration characteristics of the moving blade due to the change in the operating condition, and to improve the reliability of the turbine product.

For example, Patent Document 1 discloses a technique in which a displacement sensor is provided in a stationary portion that does not contact a moving blade, and the vibration of the moving blade is monitored by the displacement sensor.
In particular, in the low pressure stage where the blade height of the moving blade is large, a non-contact monitor that measures the passing time of each moving blade from the stationary side and calculates the vibration form and amount of vibration by calculating the result is applied. Often.

  Patent Document 2 discloses a technique in which a vibration detection unit is provided in a stationary part that is in sliding contact with a rotor. For example, by installing an accelerometer as a vibration detection unit in the bearing housing, vibration from the blade row group transmitted to the bearing housing is detected by the accelerometer.

JP 2003-177059 A JP-A-53-28806

  By the way, in the technique described in Patent Document 1, particularly in a high pressure stage where the blade height of the moving blade is small, the installation environment of the displacement sensor is bad and the vibration amplitude of the moving blade is small. I can't. Also, depending on the properties of the working fluid such as steam or combustion gas, an error may occur in the detection value of the displacement sensor, and vibration may not be detected appropriately.

Further, in the technique described in Patent Document 2, in order to transmit vibration from the moving blade row group to the bearing housing, it is necessary to pass through vibration damping elements such as a bearing oil film, a bearing, and a bearing housing. Therefore, the quality of the signal itself is deteriorated, and there is a high possibility that the signal is masked by dark vibration.
Therefore, it is difficult to easily detect abnormalities in the moving blades with any technique.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a blade vibration monitoring device, a rotating machine system, and a blade vibration monitoring method capable of easily grasping abnormalities of a moving blade. .

The present invention employs the following means in order to solve the above problems.
That is, the blade vibration monitoring device according to the first aspect of the present invention includes a blade group composed of a plurality of blade arrays arranged at intervals in the axial direction on the outer periphery of a rotating shaft that rotates around the axis. A pair of bearings that support the rotary shaft so as to be rotatable about the axis so as to sandwich the blade row group from the axial direction, a pair of bearing bases that respectively support the bearings, and the rotor A blade vibration monitoring apparatus for a rotary machine having a stator, wherein the acceleration response is input from at least two acceleration sensors arranged on the outer surface of the rotary machine and spaced apart from each other in the axial direction, and a plurality of acceleration sensors. A level difference calculation unit that calculates a level difference, and a blade row specification that specifies the blade row in which an abnormality has occurred among a plurality of blade rows based on the difference calculated by the level difference calculation unit And a blade vibration monitoring device body having a.

  A blade vibration monitoring method for a rotary machine according to a second aspect of the present invention includes a blade row group composed of a plurality of blade rows arranged at intervals in the axial direction on the outer periphery of a rotating shaft that rotates about an axis. A pair of bearings that rotatably support the rotating shaft around the axis so as to sandwich the rotor blade row group from the axial direction, a pair of bearing bases that respectively support these bearings, and the rotor A blade vibration monitoring method for a rotary machine having an enclosing stator, wherein the vibration frequency acquisition step acquires an acceleration response level detected by a plurality of acceleration sensors arranged apart from the rotary machine in the axial direction, and vibration A level difference calculation step of calculating a difference in acceleration response levels of the plurality of acceleration sensors acquired by the number acquisition step, and an abnormality among the plurality of moving blade rows based on the difference calculated by the level difference calculation unit Comprising a rotor blade row specifying step of specifying the rotor blade train generated, the.

  When an abnormality occurs in any of the blades (for example, when the blade is deformed or cracked), the acceleration response level detected by multiple acceleration sensors is abnormal. It will be different compared to normal time. At this time, the acceleration response levels detected by the plurality of acceleration sensors arranged apart from each other in the axial direction are different from each other. That is, if an abnormality occurs in the moving blade row of any of the moving blade rows, the abnormal vibration propagates from the moving blade row as a base point. The abnormal vibration attenuates as the distance from the base point increases. Therefore, the acceleration response level detected by the acceleration sensor arranged close to the base point is higher than the acceleration response level detected by the acceleration sensor arranged apart from the base point.

In this aspect, using the event, a moving blade row having a moving blade in which an abnormality has occurred is identified from the difference in acceleration response levels detected by a plurality of acceleration sensors arranged apart from each other in the axial direction. That is, for example, if the value of the acceleration response level detected by one of the acceleration sensors is greater than the acceleration response level detected by the other acceleration sensor, the rotor blade row arranged close to one of the acceleration sensors is abnormally vibrated. It can be estimated that this is the base point. Further, as the difference in acceleration response level is larger, it can be estimated that the moving blade row closer to one acceleration sensor is the base point of abnormal vibration. On the other hand, for example, if the acceleration response level detected by one acceleration sensor and the acceleration response level detected by the other acceleration sensor are close, the moving blade row located at the center of these acceleration sensors is the base point of abnormal vibration. Can be estimated.
Therefore, it is possible to easily identify the moving blade row having the moving blade in which the abnormality has occurred.

  In the above aspect, the acceleration sensor is preferably provided on each of the pair of bearing bases.

  Abnormal vibrations due to the abnormalities of the moving blades in any of the moving blade rows propagate to the bearing bases on both sides in the axial direction via the rotating shaft and the bearings. In this aspect, by detecting the acceleration response level of the bearing stand by the acceleration sensor, the moving blade row having the moving blade in which an abnormality has occurred can be easily identified as described above.

  In the above aspect, the blade vibration monitoring apparatus main body determines whether or not an abnormality has occurred in the moving blade row group based on the magnitude of the acceleration response level input from each of the plurality of acceleration sensors. The moving blade row specifying unit may specify the moving blade row when the abnormality determining unit determines that the abnormality is present.

  When an abnormality occurs in the moving blades of any of the moving blade rows, the acceleration response level detected by the plurality of acceleration sensors tends to be larger than in a normal state where no abnormality has occurred. In this aspect, for example, when the acceleration response level detected by the acceleration sensor is equal to or higher than a threshold value based on the normal time, it is determined that an abnormality has occurred in the moving blades of one of the moving blade rows. Furthermore, only when the determination is made in this way, the moving blade specifying unit specifies the moving blade row in which an abnormality has occurred based on the difference between the acceleration response levels of the plurality of acceleration sensors. Thereby, it is possible to efficiently identify the moving blade abnormality and the moving blade row in which the abnormality has occurred.

  A rotary machine system according to a third aspect of the present invention includes the rotary machine and any one of the blade vibration monitoring devices described above.

  As a result, similarly to the above, it is possible to easily identify the moving blade row having the moving blade in which the abnormality has occurred.

  According to the blade vibration monitoring device, the rotating machine system, and the blade vibration monitoring method of the present invention, it is possible to easily grasp the abnormality of the moving blade.

It is a typical longitudinal section of a steam turbine system (rotary machine system) concerning an embodiment. It is a schematic diagram which shows the rotor and blade | wing vibration monitoring apparatus of the steam turbine system (rotary machine system) which concern on embodiment. It is a figure which shows the hardware constitutions of the blade vibration monitoring apparatus main body in a blade vibration monitoring apparatus in embodiment. It is a functional block diagram of the blade vibration monitoring apparatus main body in the blade vibration monitoring apparatus which concerns on embodiment. It is a flowchart which shows the procedure until the blade vibration monitoring apparatus which concerns on embodiment identifies a moving blade row group. It is a schematic diagram which shows the rotor and acceleration sensor of the steam turbine system (rotary machine system) which concern on embodiment.

Hereinafter, a steam turbine system (rotary machine system) according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the steam turbine system 1 includes a steam turbine 2 (rotary machine) and a blade vibration monitoring device 30.

  The steam turbine 2 is an external combustion engine that extracts steam energy as rotational power, and is used for a generator in a power plant. The steam turbine 2 includes a rotor 3, a thrust bearing 8, a journal bearing 9 (bearing), a bearing base 15, and a stator 20.

The rotor 3 includes a rotating shaft 4 and a moving blade row group 5.
The rotating shaft 4 has a cylindrical shape extending about an axis O along the horizontal direction. A thrust collar 4 a is formed on a part of the rotating shaft 4. The thrust collar 4a has a disk shape centering on the axis O, and projects integrally from the main body of the rotating shaft 4 to the radially outer side of the rotating shaft 4 so as to form a flange shape.

  The moving blade row group 5 is composed of a plurality of moving blade rows 6 provided on the outer periphery of the rotating shaft 4 at intervals in the direction of the axis O. Each moving blade row 6 is configured by arranging a plurality of moving blades 7 extending radially outward from the outer peripheral surface of the rotating shaft 4 at intervals in the circumferential direction. That is, each rotor blade row 6 is constituted by a plurality of rotor blades 7 provided radially at the same position in the direction of the axis O of the rotating shaft 4.

  The thrust bearing 8 supports the thrust collar 4a so as to be slidable from both sides in the axis O direction. This restricts the movement of the rotating shaft 4 in the direction of the axis O.

  A pair of journal bearings 9 is provided on both ends of the rotary shaft 4 so as to support the rotary shaft 4 from below so as to be rotatable around the axis O. That is, the pair of journal bearings 9 supports the rotary shaft 4 so as to be rotatable around the axis O so as to sandwich the blade row group 5 from the direction of the axis O.

  The journal bearing 9 has a bearing body 10 and a bearing housing 11. The bearing body 10 has a bearing pad that supports the outer peripheral surface of the rotating shaft 4 so as to be slidable through an oil film. It has a pivot etc. which support this bearing pad from the outer peripheral side so that rocking is possible. The bearing housing 11 surrounds the rotating shaft 4 from the outer peripheral side, and supports the bearing body 10 on the inner peripheral side. The bearing housing 11 has a pivot fixed to the inner peripheral surface, and supports the bearing pad via the pivot. There may be other members such as a guide ring inside the bearing housing 11.

  The bearing stand 15 is provided with a pair so as to support the pair of journal bearings 9 from below. That is, like the journal bearing 9, the bearing stand 15 is arranged so as to sandwich the rotor blade row group 5 from the axis O direction. Each of these bearing stands 15 supports the lower half of the corresponding journal bearing 9.

The stator 20 includes a casing 21 and a stationary blade row group 22.
The casing 21 is provided so as to surround a part of the rotor 3 and the outer peripheral side. The rotating shaft 4 of the rotor 3 passes through the casing 21 in the direction of the axis O. Both ends of the rotating shaft 4 are located outside the casing 21, and are supported by the thrust bearing 8 and the journal bearing 9 outside the casing 21. The rotor blade row group 5 of the rotor 3 is disposed inside the casing 21.

  The stationary blade row group 22 is configured by a plurality of stationary blade rows 23 provided on the inner periphery of the casing 21 at intervals in the axis O direction. Each stationary blade row 23 is configured by arranging a plurality of stationary blades 24 extending radially inward from the inner peripheral surface of the casing 21 at intervals in the circumferential direction. That is, each stationary blade row 23 is configured by a plurality of stationary blades 24 provided radially at the same axis O direction position of the rotating shaft 4. The stationary blade rows 23 are alternately arranged in the direction of the axis O with the moving blade rows 6 of the rotor 3.

  In such a steam turbine 2, the steam introduced into the casing 21 passes through the flow path between the stationary blade row 23 and the moving blade row 6. At this time, the steam rotates the rotor blade 7 to rotate the rotating shaft 4 along with the rotor blade 7, and power (rotational energy) is transmitted to a machine such as a generator connected to the rotating shaft 4. .

Next, the blade vibration monitoring device 30 will be described.
The blade vibration monitoring device 30 includes a pair of acceleration sensors 40A and 40B and a blade vibration monitoring device main body 50, as shown in FIGS.
The pair of acceleration sensors 40A and 40B are provided on the bearing base 15, respectively. That is, one acceleration sensor 40A (hereinafter referred to as the first acceleration sensor 40A) of the pair of acceleration sensors 40A and 40B is one side of the pair of bearing bases 15 in the axis O direction (the right side in FIGS. 1 and 2). ). The other acceleration sensor 40B (hereinafter referred to as the second acceleration sensor 40B) is provided on the bearing base 15 on the other side (left side in FIGS. 1 and 2) in the axis O direction of the pair of bearing bases 15. As described above, the pair of acceleration sensors 40A and 40B are attached to the steam turbine 2 so as to be separated from each other in the direction of the axis O.

  In the present embodiment, the first acceleration sensor 40 </ b> A and the second acceleration sensor 40 </ b> B are provided on the upper surface of the bearing base 15 that extends along the horizontal plane. For example, the first acceleration sensor 40A and the second acceleration sensor 40B detect an acceleration response in the vertical direction of the bearing base 15 in a state where the steam turbine 2 is operated. More specifically, the sensitivity axes of the first acceleration sensor 40 </ b> A and the second acceleration sensor 40 </ b> B coincide with the direction orthogonal to the upper surface of the bearing base 15. Therefore, when the rotor 3 rotates during the operation of the turbine, the acceleration response of the bearing base 15 based on the vibration transmitted to the bearing base 15 via the journal bearing 9 is detected.

  For example, piezoelectric sensors are employed as the first acceleration sensor 40A and the second acceleration sensor 40B. The piezoelectric sensor uses a piezoelectric effect. When acceleration acts on the piezoelectric sensor, an electric charge is generated based on the stress at that time. The charges generated in this way become the outputs of the acceleration sensors 40A and 40B. The acceleration response of the bearing stand 15 is detected by the acceleration sensors 40A and 40B, and a charge signal based on the acceleration response is output. The acceleration sensors 40A and 40B are electrically connected to the blade vibration monitoring apparatus main body 50. Signals from the first acceleration sensor 40A and the second acceleration sensor 40B are input to the blade vibration monitoring apparatus main body 50.

  A charge amplifier may be interposed between the first acceleration sensor 40A and the second acceleration sensor 40B and the blade vibration monitoring apparatus main body 50. In this case, charge signals as outputs of the first acceleration sensor 40A and the second acceleration sensor 40B are input to the charge amplifier. The charge amplifier is connected to an external power source. The charge amplifier converts the charge signal input from the first acceleration sensor 40A and the second acceleration sensor 40B into a voltage signal based on the power supplied from the external power source and outputs the voltage signal. The charge amplifier has a number of channels corresponding to the plurality of first acceleration sensors 40A and the second acceleration sensor 40B, and is configured to separately convert the charge signals of the plurality of acceleration sensors 40A and 40B into voltage signals and output them. Also good.

  As shown in FIG. 3, the blade vibration monitoring apparatus main body 50 includes a CPU 61 (Central Processing Unit), a ROM 62 (Read Only Memory), a RAM 63 (Random Access Memory), an HDD 64 (Hard Disk Drive), a signal receiving module 65 (receiver). ). The signal receiving module 65 receives signals from the acceleration sensors 40A and 40B.

As shown in FIG. 4, the CPU 61 of the blade vibration monitoring device main body 50 executes a program stored in advance in its own device, whereby a control unit, a frequency acquisition unit 72, an abnormality determination unit 73, a level difference calculation unit 74, Each configuration includes a cascade specifying unit 75 and an alarm unit 76.
The control unit 71 controls other functional units provided in the analysis apparatus.

The frequency acquisition unit 72 acquires signals from the first acceleration sensor 40A and the second acceleration sensor 40B, that is, acceleration response information of each bearing stand 15 with time.
The abnormality determination unit 73 determines whether or not an abnormality has occurred in the moving blade 7 of any of the moving blade rows 6 in the moving blade row group 5 based on the speed response information of each bearing stand 15 acquired by the frequency acquisition portion 72. Determine whether.

The level difference calculation unit 74 calculates the difference between the acceleration response levels of the first acceleration sensor 40A and the second acceleration sensor 40B when the abnormality determination unit 73 determines the occurrence of an abnormality.
Based on the difference calculated by the level difference calculation unit 74, the moving blade row specifying unit 75 determines whether any of the moving blade rows 6 constituting the moving blade row 6 has an abnormality. To do.
The warning unit 76 outputs a warning based on the calculation result of the blade row specifying unit. That is, when the blade row specifying unit specifies the moving blade row 6, the warning unit 76 performs a process of outputting an alarm that the abnormality has occurred and an alarm that specifies the moving blade row 6 in which the abnormality has occurred. The alarm unit 76 may perform a process of displaying alarm information on a monitor, or may perform a process of sounding an alarm as an alarm.

  Next, a blade vibration monitoring method, which is a processing procedure of the blade vibration monitoring apparatus 30 of the present embodiment, will be described using the flowchart shown in FIG. The blade vibration monitoring method includes steps of a frequency acquisition step S1, an abnormality determination step S2, a level difference calculation step S3, and a moving blade row specifying step S4.

  The frequency acquisition step S1 is a step of acquiring acceleration response information of each bearing stand 15 from the first acceleration sensor 40A and the second acceleration sensor 40B by the frequency acquisition unit 72. In the frequency acquisition step S1, acceleration response information from the first acceleration sensor 40A and the second acceleration sensor 40B is acquired with time. In the frequency acquisition step S1, the time history of the acceleration response waveform of each bearing stand 15, that is, the time history of the vibration waveform is acquired.

  The abnormality determination step S <b> 2 is a step in which the abnormality determination unit 73 determines whether an abnormality has occurred in the moving blade 7 group of the rotor 3 based on the acceleration response information of each bearing stand 15. In the abnormality determination step S2, an acceleration response level (vibration acceleration level) of each bearing stand 15 corresponding to the acceleration response is obtained from the acceleration response of each bearing stand 15 acquired in the frequency acquisition step S1. The acceleration response level may be obtained based on the average value per unit time of the acceleration response of each bearing stand 15.

Here, when an abnormality occurs in the moving blade 7 of any one of the moving blade rows 6 (for example, when the moving blade 7 is deformed or cracked), the acceleration response level of the bearing base 15 is It is different from the normal time when no abnormality has occurred (when the blade 7 is not deformed / damaged in any blade row 6), especially compared to the normal time when no abnormality has occurred. Tend to grow.
Therefore, in the abnormality determination step S2, the acceleration response level of each bearing base 15 is compared with the acceleration response level of each bearing base 15 acquired in advance during normal operation. When the acceleration response level of each bearing stand 15 is sufficiently larger than the normal acceleration response level, for example, when exceeding the threshold value based on the normal acceleration response level, the moving blade row group 5 It is determined that an abnormality has occurred.

  The level difference calculation step S3 is performed when it is determined that there is an abnormality in the abnormality determination step S2. The level difference calculation step S3 is a step in which the level difference calculation unit 74 calculates the difference between the acceleration response levels of the respective bearing bases 15. That is, in the level difference calculation step S3, the acceleration response level of each bearing base 15 is obtained based on the acceleration response of each bearing base 15 acquired in the frequency acquisition step S1. And the difference of the acceleration response level of each bearing stand 15 is calculated.

  In the moving blade row specifying step S4, the moving blade row specifying unit 75 specifies the moving blade row 6 having the moving blade 7 in which an abnormality has occurred among the plurality of moving blade rows 6. In the moving blade row specifying step S4, the moving blade row 6 in which an abnormality has occurred is specified based on the difference between the acceleration response levels.

  Here, when an abnormality occurs in the moving blade 7 of any one of the moving blade rows 6, the acceleration response level detected by the first acceleration sensor 40A and the second acceleration sensor 40B that are spaced apart in the direction of the axis O is detected. Are different from each other. That is, if an abnormality occurs in the moving blade 7 of any one of the moving blade rows 6, abnormal vibration propagates from the moving blade row 6 as a base point. The abnormal vibration attenuates as the distance from the base point increases. Therefore, the acceleration response level detected by one of the first acceleration sensor 40A and the second acceleration sensor 40B that is arranged close to the base point is higher than the acceleration response level detected by the other of the first acceleration sensor 40A and the second acceleration sensor 40B that are arranged apart from the base point. growing.

In the moving blade row specifying step S4, using this event, the motion in which an abnormality has occurred is determined from the difference in the acceleration response levels detected by the first acceleration sensor 40A and the second acceleration sensor 40B that are arranged apart in the direction of the axis O. A moving blade row 6 having blades 7 is specified.
That is, for example, as shown in FIG. 6A, if the acceleration response level R1 detected by the first acceleration sensor 40A is greater than the acceleration response level R2 detected by the second acceleration sensor 40B, the first It can be estimated that the moving blade row 6 arranged close to the acceleration sensor 40A is the base point of abnormal vibration.

  On the other hand, as shown in FIG. 6B, if the magnitudes of the acceleration response level R1 detected by the first acceleration sensor 40A and the acceleration response level R2 detected by the second acceleration sensor 40B are approximate, these accelerations are detected. It can be estimated that the moving blade row 6 located in the center of the sensors 40A and 40B is the base point of abnormal vibration.

  Further, as shown in FIG. 6C, for example, if the acceleration response level R1 detected by the second acceleration sensor 40B is greater than the acceleration response level R2 detected by the first acceleration sensor 40A, the second It can be estimated that the moving blade row 6 arranged close to the acceleration sensor 40B is the base point of abnormal vibration.

Here, for example, assuming that the steam turbine 2 includes four or more moving blade rows 6, for example, when the acceleration response level of the first acceleration sensor 40 </ b> A is larger, the difference in the acceleration response level is larger. It can be estimated that the moving blade row 6 closer to the first acceleration sensor 40A is the base point of abnormal vibration. On the other hand, for example, when the acceleration response level of the second acceleration sensor 40B is larger, the larger the difference in the acceleration response level, the closer the moving blade row 6 closer to the second acceleration sensor 40B is the base point of abnormal vibration. Can be estimated. Therefore, in the moving blade row specifying step S4, the moving blade row 6 having the moving blade 7 in which an abnormality has occurred can be specified based on the difference between the acceleration response levels of the first acceleration sensor 40A and the second acceleration sensor 40B. .
For example, a table of the relationship between the difference and the moving blade row 6 in which the abnormality has occurred may be stored in advance, and the moving blade row 6 in which the abnormality has occurred may be specified from the calculated difference and the table.

  As described above, according to the present embodiment, the moving blade having the moving blade 7 in which the abnormality has occurred based on the difference between the acceleration response levels acquired by the first acceleration sensor 40A and the second acceleration sensor 40B from the respective bearing bases 15. Column 6 can be easily identified.

  Since the specification of the moving blade row 6 is based on the detection of the acceleration sensors 40A and 40B installed on the respective bearing bases 15, it is not necessary to construct a complicated system configuration. Further, for example, as in the case of directly detecting the vibration of the moving blade 7 in the casing 21 of the steam turbine 2, the sensor may not be installed in a harsh environment. Furthermore, since it is only necessary to install the first acceleration sensor 40A and the second acceleration sensor 40B on the upper surface of the bearing base 15, the construction at the time of system construction is easy and the first acceleration sensor 40A and the second acceleration sensor 40B Maintenance can be performed easily.

  In addition, abnormal vibration due to abnormality of the rotor blade 7 of any one of the rotor blade rows 6 propagates to the bearing bases 15 on both sides in the axis O direction via the rotating shaft 4 and the journal bearing 9, so that the acceleration response level of the bearing base 15 Is detected by the acceleration sensors 40A and 40B, the moving blade row 6 having the moving blade 7 in which an abnormality has occurred can be easily identified.

  Further, in the present embodiment, for example, when the acceleration response level detected by the acceleration sensors 40A and 40B exceeds a threshold value based on the normal time, an abnormality has occurred in the moving blade 7 of any moving blade row 6. judge. Furthermore, only when determined in this way, the moving blade 7 specifying unit specifies the moving blade row 6 in which an abnormality has occurred based on the difference in acceleration response levels of the plurality of acceleration sensors 40A and 40B. Thereby, it is possible to efficiently identify the abnormality of the moving blade 7 and the moving blade row 6 in which the abnormality has occurred.

  The embodiment of the present invention has been described above, but the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the present invention.

  For example, in the embodiment, an example using two of the first acceleration sensor 40A and the second acceleration sensor 40B has been described. However, a plurality of acceleration sensors that are separated from each other in the direction of the axis O may be provided. When an abnormality occurs in the moving blade row 6, by comparing two arbitrary acceleration response levels among the acceleration response levels of each of the three or more acceleration sensors, the movement in which the abnormality has occurred can be performed with higher accuracy. The cascade 6 can be identified.

  For example, in the embodiment, an example in which the first acceleration sensor 40 </ b> A and the second acceleration sensor 40 </ b> B are respectively installed on the pair of bearing bases 15 has been described. It may be provided. In this case, even if one acceleration sensor of one bearing base 15 breaks down, the acceleration response of the bearing base 15 is acquired by another acceleration sensor installed on the one bearing base 15, thereby causing an abnormality. It is possible to identify the moving blade row 6 in which the occurrence of the above has occurred. Further, by acquiring the acceleration response of each bearing stand 15 with a plurality of acceleration sensors, it is possible to specify the moving blade row 6 in which an abnormality has occurred with higher accuracy.

  Furthermore, in the embodiment, the first acceleration sensor 40 </ b> A and the second acceleration sensor 40 </ b> B are provided on the bearing base 15, but the installation location is not limited to the bearing base 15. The plurality of acceleration sensors 40A and 40B may be provided in other parts such as the casing 21, the rotor 3, and the journal bearing 9 of the rotary machine, for example. Even in this case, if an abnormal vibration propagates to the first acceleration sensor 40A and the second acceleration sensor 40B when an abnormality occurs in the moving blade row 6, the moving blade in which an abnormality has occurred as in the embodiment. Column 6 can be identified.

  Further, for example, frequency analysis may be performed on the acceleration responses detected by the first acceleration sensor 40A and the second acceleration sensor 40B, and the acceleration response level may be obtained only from the most prominent vibration mode among the plurality of vibration modes. Even in this case, the rotor blade row 6 in which an abnormality has occurred can be estimated as in the embodiment.

  Further, for example, in the embodiment, the example in which the present invention is applied to the steam turbine 2 has been described. However, the present invention may be applied to other rotating machines such as a gas turbine.

DESCRIPTION OF SYMBOLS 1 Steam turbine system 2 Steam turbine 3 Rotor 4 Rotating shaft 4a Thrust collar 5 Rotor blade group 6 Rotor blade row 7 Rotor blade 8 Thrust bearing 9 Journal bearing 10 Bearing body 11 Bearing housing 15 Bearing stand 20 Stator 21 Casing 22 Stator blade row Group 23 Static blade row 24 Static blade 30 Blade vibration monitoring device 40A First acceleration sensor 40B Second acceleration sensor 50 Blade vibration monitoring device main body 61 CPU
62 ROM
63 RAM
64 HDD
65 Signal Receiving Module 71 Control Unit 72 Vibration Acquisition Unit 73 Abnormality Determination Unit 74 Level Difference Calculation Unit 75 Rotor Blade Row Identification Unit 76 Alarm Unit S1 Frequency Acquisition Step S2 Abnormality Determination Step S3 Level Difference Calculation Step S4 Rotor Blade Row Identification Step

Claims (5)

A rotor having a moving blade row group consisting of a plurality of moving blade rows provided at intervals in the axial direction on the outer periphery of a rotating shaft that rotates around an axis;
A pair of bearings that rotatably support the rotary shaft around the axis so as to sandwich the blade row group from the axial direction;
A pair of bearing stands for supporting these bearings,
And a blade vibration monitoring device for a rotary machine having a stator surrounding the rotor,
A plurality of acceleration sensors spaced apart in the axial direction on the rotating machine;
A level difference calculation unit that calculates a difference between acceleration response levels respectively input from the plurality of acceleration sensors, and an abnormality has occurred in the plurality of moving blade rows based on the difference calculated by the level difference calculation unit A blade vibration monitoring device main body having a blade row specifying part for specifying the blade row;
Wing vibration monitoring device comprising:   The blade vibration monitoring apparatus according to claim 1, wherein the acceleration sensor is provided on each of the pair of bearing bases. The blade vibration monitoring device body is
An abnormality determination unit that determines whether an abnormality has occurred in the moving blade row group based on the magnitude of the acceleration response level input from each of the plurality of acceleration sensors;
The blade vibration monitoring device according to claim 1 or 2, wherein the moving blade row specifying unit specifies the moving blade row when the abnormality determination unit determines that the abnormality is present. The rotating machine;
The blade vibration monitoring device according to any one of claims 1 to 3,
A rotating machine system comprising: A rotor having a moving blade row group consisting of a plurality of moving blade rows provided at intervals in the axial direction on the outer periphery of a rotating shaft that rotates around an axis;
A pair of bearings that rotatably support the rotary shaft around the axis so as to sandwich the blade row group from the axial direction;
A pair of bearing stands for supporting these bearings,
And a blade vibration monitoring method for a rotary machine having a stator surrounding the rotor,
A frequency acquisition step of acquiring an acceleration response level detected by a plurality of acceleration sensors arranged apart from each other in the axial direction on the rotating machine;
A level difference calculation step of calculating a difference between acceleration response levels of the plurality of acceleration sensors acquired by the frequency acquisition step;
A blade row specifying step for specifying the blade row in which an abnormality has occurred among the plurality of blade rows based on the difference calculated by the level difference calculation unit;
Including blade vibration monitoring method.

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