JP2018165653A - Blade irregularity detection device, blade irregularity detection system, revolving machine system, and blade irregularity detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade irregularity detection device that can easily detect irregularity of revolving blades.SOLUTION: A blade irregularity detection device comprises: an acceleration information acquisition unit 53 that acquires acceleration information on a steam turbine; a revolving position information acquisition unit 54 that acquires revolving position information on a revolving shaft; a valve information acquisition unit 52 that acquires valve information indicative of an opening/closing state of a plurality of opening/closing valves; a partial load determination unit 55 that determines whether only one opening/closing valve of the plurality of opening/closing valves is a partial load state put into an opening state on the basis of the valve information; a blade irregularity determination unit 56 that, when the partial load determination unit determines that the one opening/closing valve is in the partial load state, determines presence or absence of irregularity of a first-step revolving blade row on the basis of a time sequence of the acceleration information; and a blade identification unit 57 that, when it is determined that the first-step revolving blade row is irregular, identifies the revolving blade having the irregularity generated from the first-step revolving blade row on the basis of the revolving position information.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a blade abnormality detection device, a blade abnormality detection system, a rotating machine system, and a blade abnormality detection 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 a problem, and provides a blade abnormality detection device, a blade abnormality detection system, a rotating machine system, and a blade abnormality detection method that can easily grasp a blade abnormality. For the purpose.

  The present invention employs the following means in order to solve the above problems. A rotating shaft rotating around an axis, and a moving blade row group including a plurality of moving blade rows having a plurality of moving blades extending radially from the rotating shaft in the axial direction that is a flow direction of the working fluid; A plurality of inlets that surround the rotor blade row group from the outer peripheral side and introduce a plurality of inlets into the first row of rotor blade rows in the circumferential direction of the axis, and a plurality of inlets corresponding to the inlets are provided. And an opening / closing valve for opening and closing the flow path of the working fluid supplied to the introduction port, respectively, and a blade abnormality detection device for a rotating machine, the acceleration information acquiring unit acquiring acceleration information of the rotating machine A rotation position information acquisition unit that acquires rotation position information of the rotation shaft, a valve information acquisition unit that acquires valve information indicating an open / close state of the plurality of on-off valves, and a plurality of the opening / closing operations based on the valve information Only some of the on-off valves are open. A partial load determination unit that determines whether or not the partial load state is in a state, and when the partial load determination unit determines that the partial load state is present, the partial load determination unit is further configured based on the time series of the acceleration information. A blade abnormality determining unit that determines whether or not there is an abnormality in the moving blade row of the eye, and when it is determined that the first row of moving blade rows is abnormal, the first step A blade specifying unit that specifies the moving blade in which an abnormality has occurred in the moving blade row.

In the rotating machine, the working fluid is introduced from all the inlets by opening all of the opening / closing valves of the plurality of inlets at full load. On the other hand, at the time of partial load, only the opening / closing valves of some introduction ports are opened and the remaining opening / closing valves are closed, so that the working fluid is introduced from only some of the introduction ports.
At such a partial load, the rotating blades in the first row of blades are vibrated by the working fluid only when passing near the circumferential position of the inlet to which the working fluid is introduced. It will be.

  Under normal conditions in which all of the moving blades are not deformed / damaged, the moving blades that pass through the vicinity of the inlet through which the working fluid is introduced vibrate in a similar manner due to the exciting force of the working fluid. On the other hand, when any one of the moving blades is deformed or damaged, only the rigidity of the moving blade is reduced compared to other moving blades. It will vibrate greatly. Therefore, as a whole rotating machine, the acceleration due to vibration shows a large value only when the moving blade in which an abnormality has occurred passes through the vicinity of the inlet through which the working fluid is introduced.

  In this aspect, based on the above knowledge, a moving blade in which an abnormality has occurred in the first-stage moving blade row is specified. That is, when the partial load determination unit determines that the working fluid is introduced only from one of the inlets, the first stage blade row is abnormal based on the acceleration of the rotating machine. Determine whether it occurred. Next, when it is determined that an abnormality has occurred, a moving blade in which an abnormality has occurred is identified from a plurality of moving blades based on the rotational position of the rotating shaft. As a result, the abnormality of the moving blade can be easily identified.

  In the blade abnormality detection device, the blade abnormality determination unit acquires the time series of the acceleration information of the rotating machine in a normal state in which no abnormality has occurred in the first row of moving blades, and the acceleration information acquisition unit acquires It is preferable to compare the time series of the acceleration information to determine whether or not the first stage blade row is abnormal.

  By comparing the normal acceleration information acquired in advance with the actual acceleration information acquired by the acceleration information acquisition unit, it is possible to determine that the actual acceleration information is significantly different from the normal acceleration information. .

  A blade abnormality detection system according to a second aspect of the present invention includes the above-described blade abnormality detection device, an acceleration sensor that detects acceleration of the rotating machine and outputs the acceleration to the blade abnormality detection device, and a rotational position of the rotating shaft. And a rotation sensor that detects and outputs the blade abnormality detection device.

  By using the acceleration information by the acceleration sensor and the rotational position information by the rotation sensor, it is possible to easily detect the abnormality of the moving blade as described above.

A rotary machine system according to a third aspect of the present invention includes the rotary machine and the blade abnormality detection system, and the rotary machine controls each on-off valve and provides valve information to the blade abnormality detection device. Has an on-off valve controller.
This makes it possible to easily detect abnormalities in the moving blades.

  In the rotary machine system, the rotary machine includes a bearing that rotatably supports the rotary shaft around the axis, and a bearing base that supports the bearing from below, and the acceleration sensor is mounted on the bearing base. It is preferable to be provided.

  Since the acceleration sensor for detecting the vibration of the rotating machine is provided on the outer surface of the rotating machine, the acceleration information can be acquired without being affected by the properties of the working fluid.

  The blade abnormality detection method according to the fourth aspect of the present invention includes a rotating shaft rotating around an axis and a moving blade row having a plurality of moving blades extending radially from the rotating shaft in the axial direction in which the working fluid flows. A plurality of moving blade row groups provided in a plurality of stages, and surrounding the moving blade row groups from the outer peripheral side, a plurality of introduction ports for introducing working fluid into the first moving blade row are arranged in the circumferential direction of the axis. A rotating machine blade abnormality detection method comprising a stator and a plurality of open / close valves provided corresponding to each of the introduction ports, each of which opens and closes a flow path of the working fluid supplied to the introduction port, Acceleration information acquisition step of acquiring acceleration information of the rotating machine, rotation position information acquisition step of acquiring rotation position information of the rotating shaft, and valve information acquisition of acquiring valve information indicating the open / closed states of the plurality of on-off valves Based on the process and the valve information, multiple A partial load determining step for determining whether or not only a part of the on / off valves is in a partial load state, and the partial load determination unit determines that the partial load state is in effect In this case, it is determined that the blade abnormality determining step for determining whether or not the first stage of the moving blade row is abnormal based on the time series of the acceleration information, and the first stage of the moving blade row is abnormal. A blade specifying step of specifying the moving blade in which an abnormality has occurred from the first row of moving blades based on the rotational position information.

According to the blade abnormality detection device, the blade abnormality detection system, the rotating machine system, and the blade abnormality detection method of the present invention, it is possible to easily detect 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 typical sectional view orthogonal to the axis of a steam turbine system (rotary machine system) concerning an embodiment. It is a figure which shows the hardware constitutions of the wing | blade monitoring apparatus main body in a wing | blade monitoring apparatus in embodiment. It is a functional block diagram of the wing | blade monitoring apparatus main body in the wing | blade monitoring apparatus which concerns on embodiment. (a) is a graph showing a time series of rotational position information and acceleration information in a normal state, and (b) is a graph showing a time series of rotational position information and acceleration information in an abnormal state. It is a flowchart of the wing | blade abnormality detection method which concerns 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 FIGS. 1 and 2, the steam turbine system 1 includes a steam turbine 2 (rotary machine) and a blade abnormality detection system 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, a stator 20, an on-off valve, and an on-off valve controller.

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. 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. A pivot for supporting the bearing pad from the outer peripheral side so as to be swingable is provided. 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. Each of these bearing stands 15 supports the lower half of the corresponding journal bearing 9.
One of the pair of bearing bases 15 (the right side bearing base 15 in FIG. 1) has an upper surface 16 that extends to the side of the steam turbine 2, as shown in detail in FIG.

As shown in FIG. 1, 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.

As shown in FIG. 1, on the upstream side of the first stage moving blade row 6 and the stationary blade row 23 in the casing 21, a steam introducing portion 25 for introducing steam as a working fluid into the casing 21 is formed. Has been.
The steam introduction part 25 has a plurality of (four in this embodiment) introduction ports 26. Each inlet 26 penetrates the inside and outside of the casing 21 so that steam can be introduced from the outer peripheral side of the casing 21 toward the inside. Each introduction port 26 has a cylindrical shape protruding from the outer peripheral surface of the casing 21, and the distal end of the cylindrical outer peripheral side is formed in a flange shape. The plurality of inlets 26 are formed at intervals in the circumferential direction of the axis O. In the present embodiment, two of the four inlets 26 are formed in the upper part of the casing 21, and the remaining two are formed in the lower part of the casing 21. Moreover, the inner part of each inlet 26 in the casing 21 is partitioned into chambers separated from each other in the circumferential direction.

  Each inlet 26 is connected to a steam line 27b (flow path) through which steam supplied from a steam supply source 27a such as a boiler flows. The steam generated by the steam supply source 27 a is introduced into the casing 21 through the steam line 27 b and the plurality of inlets 26.

  The on-off valves 28 are provided so as to correspond to the respective inlets 26, and open and close the steam lines 27 b for introducing steam into the inlets 26. When the on-off valve 28 is in the open state, steam is introduced into the casing 21 through the inlet 26 corresponding to the on-off valve 28. When the on-off valve 28 is in a closed state, no steam flows through the inlet 26 corresponding to the on-off valve 28, and no steam is introduced into the casing 21 through the inlet 26. The above flowing into the inlet 26 is introduced into the first stage moving blade row 6 via the first stage stationary blade row 23.

The on-off valve control unit 29 controls the open / close state of the plurality of on-off valves 28. The on-off valve control unit 29 can control the open / close state of the plurality of on-off valves 28 independently for each of the plurality of on-off valves 28.
The on-off valve control unit 29 controls the open / close state of each on-off valve 28 according to the degree of load. For example, when full load is applied, steam is introduced into the casing 21 through all the inlets 26 by opening all the on-off valves 28. On the other hand, at the time of partial load, at least one of the plurality of on-off valves 28 is closed, and the flow rate of the steam introduced into the casing 21 is reduced. At this time, the number of on-off valves 28 to be closed is determined according to the degree of partial load. During full load, steam is introduced into the casing 21 from a wide area in the circumferential direction. On the other hand, at the time of partial load, steam is introduced into the casing 21 only from a part in the circumferential direction.

  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 abnormality detection system 30 will be described.
As shown in FIG. 2, the blade abnormality detection system 30 includes an acceleration sensor 40, a rotation sensor 41, and a blade abnormality detection device 50.

  The acceleration sensor 40 is provided on the bearing stand 15 of the steam turbine 2. The vibration generated in the moving blade row 6 of the steam turbine 2 propagates to the bearing base 15 via the rotating shaft 4, the bearing body 10 of the journal bearing 9 and the bearing housing 11. The acceleration sensor 40 detects the vibration thus propagated as acceleration.

As the acceleration sensor 40, for example, a piezoelectric sensor is employed. 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 charge generated in this way becomes the output of the acceleration sensor 40. The vibration of the rotor blade row 6 of the rotor is propagated to the bearing base 15, and the vibration is detected as an acceleration by the acceleration sensor 40 and output to the blade abnormality detecting device 50 as an acceleration signal. The acceleration signal indicates a waveform corresponding to the vibration (acceleration) of the rotating machine.
As the acceleration sensor 40, a sensor other than the piezoelectric sensor may be used.

The rotation sensor 41 detects the rotation position of the rotation shaft 4. That is, the rotation sensor 41 detects the rotation angle (rotation phase) of the rotation shaft 4 that rotates about the axis O. In the present embodiment, the rotation sensor 41 uses an optical rotation sensor. The optical rotation sensor irradiates light toward the outer peripheral surface of the rotating shaft 4 and receives reflected light reflected from the outer peripheral surface. A reflective material is provided on a part of the outer circumferential surface of the rotating shaft 4 in the circumferential direction. Thereby, the intensity | strength of reflected light becomes large only when the reflecting material of the rotating shaft 4 arrives at the light irradiation position of an optical rotation sensor. Thereby, the intensity | strength of reflected light will show the peak for every rotation of the rotating shaft 4. FIG. Similarly, the rotation position signal that is the output of the rotation sensor 41 shows a waveform that shows a peak for each rotation of the rotation shaft 4. The rotation sensor 41 may detect the rotation position of the rotation shaft 4 inside the casing 21 or may detect the rotation position of the rotation shaft 4 outside the casing 21.
In addition, as the rotation sensor 41, you may use things other than the said aspect.

As shown in FIG. 3, the blade abnormality detection device 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), and a signal receiving module 65 (receiver). It is a computer provided with. The signal receiving module 65 receives an acceleration signal (acceleration information) output from the acceleration sensor 40 and a rotation position signal (rotation position information) output from the rotation sensor 41. The signal receiving module 65 receives valve information indicating the open / closed states of the plurality of open / close valves 28 from the open / close valve control unit 29. That is, the on-off valve control unit 29 controls the opening / closing of each on-off valve 28 and outputs steam valve information to the blade abnormality detection device 50.
Note that the acceleration signal output from the acceleration sensor 40 and the rotational position signal output from the rotation sensor 41 may be amplified by an amplifier and input to the signal receiving module 65.

As shown in FIG. 4, the CPU 61 of the blade abnormality detection device 50 executes a program stored in advance in its own device, whereby a control unit 51, a valve information acquisition unit 52, an acceleration information acquisition unit 53, and a rotational position information acquisition unit 54. , A partial load determination unit 55, a blade abnormality determination unit 56, a blade specification unit 57, and an alarm unit 58.
The control unit 51 controls other functional units provided in the analysis apparatus.

The valve information acquisition unit 52 acquires the valve information received by the signal reception module 65. That is, the valve information acquisition unit 52 acquires information about whether each of the plurality of on-off valves 28 is open or closed.
The acceleration information acquisition unit 53 acquires acceleration information received by the signal reception module 65 together with time. That is, the acceleration information acquisition unit 53 acquires a time series of acceleration information.
The rotational position information acquisition unit 54 acquires the rotational position information received by the signal reception module 65 together with the time. That is, the rotational position information acquisition unit 54 acquires a time series of rotational position information.

The partial load determination unit 55 determines whether or not the partial load state is based on the valve information acquired by the valve information acquisition unit 52.
Specifically, the partial load determination unit 55 determines that the steam turbine 2 is in a full load state when acquiring valve information in which all of the plurality of on-off valves 28 are in an open state. On the other hand, the partial load determination unit 55 determines that the steam turbine 2 is in the partial load state when a part (at least one) of the plurality of on-off valves 28 is in the closed state. The partial load determination unit 55 is a partial load that can determine a blade abnormality only when only one of the plurality of on-off valves 28 is open and the remaining on-off valves 28 are closed. It is preferable to determine the state. When only one on-off valve 28 (for example, the upper-right on-off valve 28 in FIG. 2) is in an open state, a steam inflow region S shown in FIG. 2 is formed in a partial chamber in the circumferential direction inside the casing 21.

  The blade abnormality determination unit 56 is based on the time series of the acceleration information acquired by the acceleration information acquisition unit 53 when the partial load determination unit 55 determines that the steam turbine 2 is in the partial load state. The presence or absence of abnormality in column 6 is determined.

  That is, the abnormality determination unit compares the time series of the acceleration information of the steam turbine 2 at normal time when no abnormality has occurred in the first stage blade row 6 and the time series of the acceleration information acquired by the acceleration information acquisition unit 53. Then, it is determined whether or not the first blade row 6 is abnormal. The normal acceleration information is acceleration information of the steam turbine 2 detected in advance in the normal state. The abnormality determination unit determines that an abnormality has occurred in the first row of blades 6 when the acquired acceleration information deviates significantly compared to the normal acceleration information. The abnormality determination unit determines a threshold value in advance with reference to normal acceleration information, for example, and determines that an abnormality has occurred in the first stage blade row 6 when the acquired acceleration information exceeds the threshold value. May be.

  The blade specifying unit 57 determines the first-stage moving blade based on the rotational position information acquired by the rotational position information acquiring unit 54 when the blade abnormality determining unit 56 determines that the first-stage moving blade row 6 is abnormal. The moving blade 7 in which an abnormality has occurred is identified from the row 6. That is, the wing specifying unit 57 matches the time series of acceleration information and the time series of rotational position information. Thereby, when the acceleration value of the acceleration information deviates greatly, the calculation for specifying the moving blade 7 (the moving blade 7 located in the steam inflow region S shown in FIG. 2) that is in the state closest to the introduction port 26 is performed. I do. In the calculation, information on which on-off valve 28 is in an open state may be used based on the valve information output from the on-off valve control unit 29. Further, if it is determined which open / close valve 28 is open at the time of partial load, it is possible to calculate the moving blade 7 by assuming that steam is introduced from a specific inlet 26 at the time of partial load. Good.

  The alarm unit 58 outputs an alarm based on the calculation result of the wing specifying unit 57. That is, when the blade specifying unit 57 specifies the abnormal moving blade 7, the warning unit 58 performs processing to output an alarm indicating that an abnormality has occurred and identifying the moving blade 7 in which the abnormality has occurred. The alarm unit 58 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 abnormality detection method in the steam turbine system 1 of the present embodiment will be described using the flowchart shown in FIG. The blade abnormality detection method includes the valve information acquisition step S1, the acceleration information acquisition step S2, the rotational position information acquisition step S3, the partial load determination step S4, the blade abnormality determination step S5, the blade identification step S6, and the warning step S7. To do.

  In valve information acquisition process S1, valve information is acquired. In the acceleration information acquisition step S2, acceleration information is acquired together with time. The rotational position information acquisition step S3 acquires rotational position information together with time. These three steps may be performed simultaneously.

The partial load determination step S4 is performed after the valve information acquisition step S1.
In the partial load determination step S4, it is determined whether or not the partial load state in which only one of the on-off valves 28 is in the open state is performed, as in the processing in the partial load determination unit 55.

The blade abnormality determination step S5 is performed after the partial load determination step S4 and the acceleration acquisition step S2.
In the blade abnormality determination step S5, the acceleration information acquired by the acceleration information acquisition unit 53 when the partial load determination unit 55 determines that the steam turbine 2 is in the partial load state, as processed by the blade abnormality determination unit 56. Based on this time series, the presence / absence of abnormality of the first stage blade row 6 is determined.

The blade specifying step S6 is performed after the blade abnormality determining step S5 and the rotational position information acquiring step S3.
In the blade specifying step S6, as determined by the blade specifying unit 57, when it is determined that the first-stage moving blade row 6 is abnormal, the first step is performed based on the rotation position information acquired by the rotation position information acquiring unit 54. A moving blade 7 in which an abnormality has occurred is identified from the moving blade row 6 of the eye.

  Here, FIG. 5 shows a time series of waveforms of the acceleration signal and the rotational position signal during normal time and abnormal time. Whether it is normal or abnormal, the acceleration signal shows a waveform that vibrates each time the moving blade 7 passes through the inlet 26 through which steam is introduced. When normal, as shown in FIG. 5A, the change in the amplitude of the waveform is small, but when abnormal, only a part of the amplitude of the waveform is larger than the other amplitude as shown in FIG. 5B. Deviate. This is due to the passage of the moving blade 7 having an abnormality in the vicinity of the inlet 26 through which the steam is introduced. In the blade abnormality determining step S5, when the amplitude of a part of the waveform is greatly changed as shown in FIG. 5B with reference to the waveform of the normal acceleration in FIG. It is determined that an abnormality has occurred in any of the columns 6. For example, when an amplitude exceeding a threshold value is generated with reference to a normal acceleration waveform, it may be determined as abnormal. Further, a standard deviation for each amplitude may be obtained, and an abnormality may be determined when the standard deviation exceeds a threshold value.

In addition, the rotation position signal shows the same waveform regardless of whether it is normal or abnormal. That is, the rotation position signal has a peak of intensity every rotation. Since the moving blades 7 are equally provided in the circumferential direction, the rotational position of each moving blade 7 at an arbitrary time can be derived based on the peak. In the blade specifying step S6, the moving blade 7 in which an abnormality has occurred is specified by matching the acceleration signal and the rotational position signal at the time of abnormality. That is, the moving blade 7 that is in the state of being close to the vicinity of the steam inlet 26 when the peak appears in the acceleration is specified.
In the warning step S <b> 7, an alarm is output based on the calculation result of the blade specifying unit 57, similarly to the processing in the warning unit 58.

Next, the effect of the steam turbine system 1 of this embodiment is demonstrated.
When the steam turbine 2 is fully loaded, all of the on-off valves 28 corresponding to the plurality of inlets 26 are opened, so that the working fluid is introduced from all the inlets 26. On the other hand, when the steam turbine 2 is partially loaded, only the on-off valves 28 corresponding to some of the plurality of inlets 26 are opened, and the remaining on-off valves 28 are closed. Thereby, at the time of partial load, the working fluid is introduced from only some of the inlets 26.

  Under such partial load, the plurality of moving blades 7 of the first-stage moving blade row 6 vibrate only when passing through the vicinity of the inlet 26 into which steam is introduced in the circumferential region. Will receive. That is, the first stage blade 7 vibrates when it reaches the circumferential direction corresponding to the inlet 26 into which the steam is introduced.

Here, at normal time when all the moving blades 7 in the first stage moving blade row 6 are not deformed or damaged, the moving blade 7 passing near the inlet 26 into which the steam is introduced is excited by the vibration force of the steam. Vibrate almost the same way. That is, since the rigidity of all the moving blades 7 is substantially equal, each of the moving blades 7 exhibits the same vibration mode.
On the other hand, at the time of abnormality where any one of the moving blades 7 in the first row of moving blades 6 is deformed or damaged, only the rigidity of the moving blades 7 is lower than that of the other moving blades 7. Due to the decrease in rigidity, only the moving blade 7 in which an abnormality has occurred vibrates greatly as compared with the other moving blades 7. Therefore, the steam turbine 2 as a whole vibrates greatly only when the moving blade 7 having an abnormality passes through the vicinity of the inlet 26 where the steam is introduced. As a result, the acceleration sensor 40 detects acceleration information indicating a peak before one rotation.

  In the present embodiment, the moving blade 7 in which an abnormality has occurred in the first-stage moving blade row 6 is specified based on the above knowledge. That is, when it is determined by the partial load determination unit 55 that the partial load in which steam is introduced only from any one of the inlets 26 is performed, the first stage moving blade row 6 is based on the acceleration of the steam turbine 2. It is determined whether or not an abnormality has occurred. Next, when it is determined that an abnormality has occurred, the moving blade 7 in which an abnormality has occurred is identified from the plurality of moving blades 7 based on the rotational position of the rotating shaft 4. Thereby, the abnormality of the moving blade 7 can be specified easily.

  Further, since the acceleration sensor 40 is provided on the bearing stand 15 of the steam turbine 2, that is, provided on the outer surface of the steam turbine 2, the acceleration sensor 40 can acquire acceleration information without being affected by the properties of the working fluid. Can do. In addition, since the presence or absence of abnormality is determined based on the acceleration peak indicated for each rotation as described above, the peak is not easily masked by other dark vibrations or the like. Therefore, the abnormality of the moving blade 7 can be detected with high accuracy.

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, although the acceleration sensor 40 is provided on the bearing base 15 in the embodiment, it may be provided on the outer surface of another steam turbine 2, for example, the journal bearing 9, the casing 21, or the rotating shaft 4 exposed to the outside of the casing 21. Moreover, you may provide in the rotating shaft 4 grade | etc., Inside the casing 21. FIG.

  Further, for example, in the embodiment, the example in which the present invention is applied to the steam turbine 2 has been described, but 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 5 Rotor blade group 6 Rotor blade row 7 Rotor blade 7a Shroud 8 Thrust bearing 9 Journal bearing 10 Bearing main body 11 Bearing housing 15 Bearing stand 16 Upper surface 20 Stator 21 Casing 22 Stator blade Row group 23 Stator blade row 24 Stator blade 25 Steam inlet 26 Inlet 27a Steam supply source 27b Steam line 28 On-off valve 29 On-off valve controller 30 Blade abnormality detection system 40 Acceleration sensor 41 Rotation sensor 50 Blade abnormality detector 51 Controller 52 Valve information acquisition unit 53 Acceleration information acquisition unit 54 Rotational position information acquisition unit 55 Partial load determination unit 56 Blade abnormality determination unit 57 Blade identification unit 58 Alarm unit 61 CPU
62 ROM
63 RAM
64 HDD
65 Signal receiving module S1 Valve information acquisition step S2 Acceleration information acquisition step S3 Rotational position information acquisition step S4 Partial load determination step S5 Blade abnormality determination step S6 Blade specification step S7 Alarm step O Axis S Steam inflow region

Claims (6)

A rotating shaft rotating around an axis, and a moving blade row group including a plurality of moving blade rows having a plurality of moving blades extending radially from the rotating shaft in the axial direction that is a flow direction of the working fluid; A plurality of inlets that surround the rotor blade row group from the outer peripheral side and introduce a plurality of inlets into the first row of rotor blade rows in the circumferential direction of the axis, and a plurality of inlets corresponding to the inlets are provided. An open / close valve that opens and closes the flow path of the working fluid supplied to the introduction port,
An apparatus for detecting an abnormality in a blade of a rotating machine comprising:
An acceleration information acquisition unit for acquiring acceleration information of the rotating machine;
A rotation position information acquisition unit for acquiring rotation position information of the rotation shaft;
A valve information acquisition unit that acquires valve information indicating an open / closed state of the plurality of on-off valves;
Based on the valve information, a partial load determination unit that determines whether or not only a part of the on / off valves among the plurality of on / off valves is in a partial load state;
When the partial load determination unit determines that the partial load state is present, a blade abnormality determination unit that determines whether or not there is an abnormality in the first row of moving blades based on the time series of the acceleration information;
When it is determined that the first row of moving blade rows is abnormal, a blade specifying unit that identifies the moving blade in which an abnormality has occurred from the first row of moving blade rows based on the rotational position information;
A wing abnormality detection device comprising: The wing abnormality determination unit
Comparing the time series of the acceleration information of the rotating machine in a normal state where no abnormality has occurred in the first row of moving blade rows and the time series of the acceleration information acquired by the acceleration information acquisition unit, The blade abnormality detection device according to claim 1, wherein it is determined whether or not the moving blade row is abnormal. The blade abnormality detection device according to claim 1 or 2,
An acceleration sensor that detects the acceleration of the rotating machine and outputs the detected acceleration to the blade abnormality detection device;
A rotation sensor that detects a rotation position of the rotation shaft and outputs the rotation position to the blade abnormality detection device;
Wing abnormality detection system comprising. The rotating machine;
A blade abnormality detection system according to claim 3,
The rotating machine system includes an on-off valve control unit that controls each on-off valve and outputs valve information to the blade abnormality detection device. The rotating machine includes a bearing that rotatably supports the rotating shaft around the axis;
A bearing stand for supporting the bearing from below;
With
The rotary machine system according to claim 4, wherein the acceleration sensor is provided on the bearing base. A rotating shaft rotating around an axis, and a moving blade row group including a plurality of moving blade rows having a plurality of moving blades extending radially from the rotating shaft in the axial direction that is a flow direction of the working fluid; A plurality of inlets that surround the rotor blade row group from the outer peripheral side and introduce a plurality of inlets into the first row of rotor blade rows in the circumferential direction of the axis, and a plurality of inlets corresponding to the inlets are provided. An open / close valve that opens and closes the flow path of the working fluid supplied to the introduction port,
A method for detecting an abnormality in a blade of a rotating machine comprising:
An acceleration information acquisition step of acquiring acceleration information of the rotating machine;
A rotation position information acquisition step of acquiring rotation position information of the rotation axis;
A valve information acquisition step for acquiring valve information indicating an open / closed state of the plurality of the open / close valves; and a partial load state in which only some of the open / close valves are open based on the valve information A partial load determination step for determining whether or not
A blade abnormality determination step for determining whether or not there is an abnormality in the first row of moving blades based on the time series of the acceleration information when the partial load determination step is determined to be in the partial load state;
When it is determined that the first row of moving blade rows is abnormal, a blade specifying step of specifying the moving blade in which an abnormality has occurred from the first row of moving blade rows based on the rotational position information;
A wing abnormality detection method including:

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