JP6811134B2 - Wing abnormality detection device, wing abnormality detection system, rotary mechanical system and wing abnormality detection method - Google Patents

Description

The present invention relates to a blade abnormality detection device, a blade abnormality detection system, a rotary mechanical system, and a blade abnormality detection method.

For example, a rotating machine such as a steam turbine or a gas turbine has a rotating shaft and a group of moving blade rows composed of a plurality of moving blade rows provided on the outer periphery of the rotating shaft. When the rotating machine is operated, the vibration of the rotating blade train is measured. By performing such measurement, it is possible to verify whether or not the vibration characteristics of the rotor blade train are as designed. In addition, changes in the vibration characteristics of the moving blades due to changes in operating conditions can be confirmed, and the reliability of turbine products can be improved.

For example, Patent Document 1 discloses a technique in which a displacement sensor is provided in a stationary portion that does not come into contact with the 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 result to calculate the vibration form and vibration amount of the moving blade is applied. Often.

Further, Patent Document 2 discloses a technique of providing a vibration detection unit in a stationary portion that is in sliding contact with a rotor. For example, by installing an accelerometer as a vibration detection unit in the bearing box, the vibration from the blade train group transmitted to the bearing box is detected by the accelerometer.

Japanese Unexamined Patent Publication No. 2003-177059 Japanese Unexamined Patent Publication No. 53-28806

By the way, in the technique described in Patent Document 1, especially 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, so that the vibration is appropriately monitored. I can't. Further, 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 box, 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 deteriorates, and there is a high possibility that the signal will be masked by dark vibration.
Therefore, it is difficult to easily detect the abnormality of the moving blade by any of the techniques.

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 rotary mechanical system, and a blade abnormality detection method capable of easily grasping an abnormality of a moving blade. The purpose is.

The present invention employs the following means in order to solve the above problems. A group of rotor blades having a rotary shaft rotating around an axis and a plurality of blade rows having a plurality of rotor blades extending radially from the rotary shaft are provided in a plurality of stages in the axial direction, which is the flow direction of the working fluid. A plurality of introduction ports for introducing the working fluid into the first stage rotor blade row are provided in the circumferential direction of the axis, and a plurality of introduction ports are provided corresponding to the respective introduction ports while surrounding the rotor blade row group from the outer peripheral side. An acceleration information acquisition unit that is a blade abnormality detection device for a rotating machine, including an on-off valve that opens and closes a flow path of the working fluid supplied to the introduction port, and acquires acceleration information of the rotating machine. Based on the rotation position information acquisition unit that acquires the rotation position information of the rotation shaft, the valve information acquisition unit that acquires the valve information indicating the open / closed state of the plurality of on-off valves, and the valve information, a plurality of the open / close valves. When the partial load determination unit for determining whether or not only a part of the on-off valves in the valve is in the open state and the partial load determination unit determine that the partial load state is present. In addition, when it is determined that the blade abnormality determination unit for determining the presence or absence of an abnormality in the moving blade row in the first stage based on the time series of the acceleration information and the moving blade row in the first stage are abnormal. A blade specifying portion that identifies the moving blade in which an abnormality has occurred from the moving blade row in the first stage based on the rotation position information is provided.

In the rotary machine, the working fluid is introduced from all the introduction ports by opening all the on-off valves of the plurality of introduction ports at the time of full load. On the other hand, at the time of partial load, only the on-off valve of a part of the introduction ports is opened and the remaining on-off valve is closed, so that the working fluid is introduced only from a part of the introduction ports.
During such a partial load, the plurality of rotating blades in the first stage rotor blades are vibrated by the working fluid only when it passes near the circumferential position of the inlet where the working fluid is introduced. It will be.

In the normal state where all the moving blades are not deformed or damaged, the moving blades passing near the introduction port into which the working fluid is introduced vibrate in almost the same manner due to the exciting force of the working fluid. On the other hand, in the event of an abnormality in which one of the rotor blades is deformed or damaged, only the rigidity of the rotor blade is lower than that of the other rotor blades, so only the rotor blade with the abnormality is compared with the other rotor blades. It will vibrate greatly. Therefore, as a whole rotating machine, the acceleration due to vibration shows a large value only when the abnormal moving blade passes near the introduction port where the working fluid is introduced.

In this aspect, based on the above findings, a moving blade in which an abnormality has occurred in the moving blade row of the first stage is specified. That is, when the partial load determination unit determines that the working fluid is being introduced only from one of the inlets at the time of partial load, an abnormality is found in the first stage rotor blade array based on the acceleration of the rotating machine. Determine if it has occurred. Next, when it is determined that an abnormality has occurred, the moving blades in which the abnormality has occurred are identified from the plurality of moving blades based on the rotation positions of the rotating shafts. Thereby, the abnormality of the moving blade can be easily identified.

In the above-mentioned blade abnormality detection device, the blade abnormality determination unit has acquired the time series of the acceleration information of the rotating machine at the normal time when no abnormality has occurred in the moving blade row in the first stage and the acceleration information acquisition unit. It is preferable to compare with the time series of the acceleration information to determine whether or not the moving blade train in the first stage is abnormal.

By comparing the normal acceleration information acquired in advance with the actual acceleration information acquired by the acceleration information acquisition unit, it can be determined that an abnormality occurs when the actual acceleration information differs significantly from the normal acceleration information. ..

The blade abnormality detection system according to the second aspect of the present invention detects the above-mentioned blade abnormality detection device, the acceleration sensor that detects the acceleration of the rotating machine and outputs it to the blade abnormality detection device, and the rotation position of the rotation shaft. It includes a rotation sensor that detects and outputs the blade abnormality detection device.

As described above, the abnormality of the moving blade can be easily detected by using the acceleration information by the acceleration sensor and the rotation position information by the rotation sensor.

The rotary machine system according to the 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 informs the blade abnormality detection device of valve information. It has an on-off valve control unit that outputs.
As a result, the abnormality of the moving blade can be easily detected.

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 attached to the bearing base. It is preferable that it is provided.

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

In the wing abnormality detection method of the fourth aspect of the present invention, the rotor blades rotating around the axis and the rotor blades having a plurality of rotor blades radially extending from the rotor blades are in the axial direction in which the working fluid flows. A plurality of blade rows provided in a plurality of stages and a plurality of introduction ports for introducing the working fluid into the first stage of the blade rows are arranged in the circumferential direction of the axis while surrounding the blade rows from the outer peripheral side. A method for detecting blade abnormality of a rotating machine, comprising a stator and an on-off valve that is provided in plurality corresponding to each of the introduction ports and opens and closes a flow path of the working fluid supplied to the introduction port. An acceleration information acquisition process for acquiring acceleration information of the rotating machine, a rotation position information acquisition process for acquiring rotation position information of the rotating shaft, and valve information acquisition for acquiring valve information indicating an open / closed state of a plurality of the on-off valves. A partial load determination step of determining whether or not only a part of the on-off valves among the plurality of on-off valves is in the open state based on the process and the valve information, and the partial load determination. When the unit determines that the partial load state is present, the blade abnormality determination step of determining whether or not there is an abnormality in the moving blade train in the first stage based on the time series of the acceleration information, and the first stage of the above. When it is determined that the rotor blades are abnormal, the blade identification step of identifying the rotor blades in which the abnormality has occurred from the first-stage rotor blades based on the rotation position information is included.

According to the blade abnormality detection device, the blade abnormality detection system, the rotary mechanical system, and the blade abnormality detection method of the present invention, the abnormality of the moving blade can be easily detected.

It is a schematic vertical sectional view of the steam turbine system (rotary mechanical system) which concerns on embodiment. It is a schematic cross-sectional view orthogonal to the axis of the steam turbine system (rotary mechanical system) which concerns on embodiment. It is a figure which shows the hardware composition of the wing monitoring apparatus main body in the wing monitoring apparatus in embodiment. It is a functional block diagram of the wing monitoring apparatus main body in the wing monitoring apparatus which concerns on embodiment. (a) is a graph showing a time series of rotation position information and acceleration information in a normal state, and (b) is a graph showing a time series of rotation position information and acceleration information in an abnormal time. It is a flowchart of the wing abnormality detection method which concerns on embodiment.

Hereinafter, the steam turbine system (rotary mechanical system) according to the embodiment of the present invention will be described with reference to FIGS. 1 to 6.
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 or the like 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 control unit.

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

The rotor blade row group 5 is composed of a plurality of rotor blade rows 6 provided on the outer periphery of the rotating shaft 4 at intervals in the axis O direction. Each rotor blade row 6 is configured by arranging a plurality of rotor 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 composed of a plurality of rotor blades 7 radially provided at the same axis O direction position of the rotating shaft 4.

The thrust bearing 8 slidably supports the thrust collar 4a from both sides in the axis O direction. As a result, the movement of the rotating shaft 4 in the axis O direction is restricted.
A pair of journal bearings 9 are provided on both ends of the rotating shaft 4 so as to rotatably support the rotating shaft 4 around the axis O from below. The journal bearing 9 has a bearing body 10 and a bearing housing 11. The bearing body 10 has a bearing pad that slidably supports the outer peripheral surface of the rotating shaft 4 via an oil film. It has a pivot or the like that swingably supports the bearing pad from the outer peripheral side. 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. A pivot is fixed to the inner peripheral surface of the bearing housing 11, and the bearing pad is supported via the pivot. There may be other members such as a guide ring inside the bearing housing 11.

A pair of bearing bases 15 are provided so as to support the pair of journal bearings 9 from below. Each of these bearing bases 15 supports the lower half of the corresponding journal bearing 9.
One of the pair of bearing bases 15 (the bearing base 15 on the right side in FIG. 1) has an upper surface 16 extending to the side of the steam turbine 2 as shown in FIG. 2 in detail.

As shown in FIG. 1, the stator 20 includes a casing 21 and a vane row group 22.
The casing 21 is provided so as to surround a part of the rotor 3 from the outer peripheral side. The rotating shaft 4 of the rotor 3 penetrates the casing 21 in the axis O direction. 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 arranged inside the casing 21.

The stationary blade row group 22 is composed of a plurality of stationary blade rows 23 provided on the inner circumference of the casing 21 at intervals in the axis O direction. Each of the stationary blade rows 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 composed of a plurality of stationary blades 24 provided radially at the same axis O direction position of the rotating shaft 4. The blade rows 23 are alternately arranged in the rotor blade rows 6 and the axis O direction of the rotor 3.

As shown in FIG. 1, a steam introduction portion 25 for introducing steam as a working fluid is formed inside the casing 21 on the upstream side of the first stage rotor blade row 6 and the stationary blade row 23 in the casing 21. Has been done.
The steam introduction unit 25 has a plurality of (four in this embodiment) introduction ports 26. Each introduction port 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 tubular shape protruding from the outer peripheral surface of the casing 21, and the tip of the tubular outer peripheral side is formed in a flange shape. The plurality of introduction ports 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. Further, the inner portion of each introduction port 26 in the casing 21 is partitioned into chambers separated from each other in the circumferential direction.

A steam line 27b (flow path) through which steam supplied from a steam supply source 27a such as a boiler flows is connected to each introduction port 26. The steam generated by the steam supply source 27a is introduced into the casing 21 via the steam line 27b and the plurality of introduction ports 26.

The on-off valve 28 is provided so as to correspond to each introduction port 26, and opens and closes the steam line 27b for introducing steam into the introduction port 26. When the on-off valve 28 is in the open state, steam is introduced into the casing 21 through the introduction port 26 corresponding to the on-off valve 28. When the on-off valve 28 is in the closed state, steam does not flow through the introduction port 26 corresponding to the on-off valve 28, and steam is not introduced into the casing 21 through the introduction port 26. The above that flows into the introduction port 26 is introduced into the first stage rotor blade row 6 via the first stage stationary blade row 23.

The on-off valve control unit 29 controls the open / closed state of the plurality of on-off valves 28. The on-off valve control unit 29 can independently control the open / closed state of the plurality of on-off valves 28 for each of the plurality of on-off valves 28.
The on-off valve control unit 29 controls the open / closed state of each on-off valve 28 according to the degree of load. For example, when the load is full, all the on-off valves 28 are opened so that steam is introduced into the casing 21 through all the introduction ports 26. On the other hand, at the time of partial load, at least one on-off valve 28 among the plurality of on-off valves 28 is closed to reduce the flow rate of steam introduced into the casing 21. At this time, the number of on-off valves 28 to be closed is determined according to the degree of partial load. At 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 from only 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, when the steam rotates the moving blade 7, the rotating shaft 4 rotates with the moving blade 7, and power (rotational energy) is transmitted to a machine such as a generator connected to the rotating shaft 4. ..

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

The acceleration sensor 40 is provided on the bearing base 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 propagated in this way as acceleration.

As the acceleration sensor 40, for example, a piezoelectric sensor is adopted. The piezoelectric sensor utilizes the piezoelectric effect. When acceleration acts on the piezoelectric sensor, an electric charge is generated based on the stress at that time. The electric charge generated in this way becomes the output of the acceleration sensor 40. The vibration of the rotor blade row 6 is propagated to the bearing base 15, and the vibration is detected by the acceleration sensor 40 as acceleration and output to the blade abnormality detecting device 50 as an acceleration signal. The acceleration signal shows 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 around 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 the reflected light reflected from the outer peripheral surface. A reflective material is provided on a part of the outer peripheral surface of the rotating shaft 4 in the circumferential direction. As a result, the intensity of the reflected light increases only when the reflective material of the rotating shaft 4 reaches the light irradiation position of the optical rotation sensor. As a result, the intensity of the reflected light peaks with each rotation of the rotating shaft 4. Similarly, the rotation position signal, which is the output of the rotation sensor 41, shows a waveform showing 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.
As the rotation sensor 41, a sensor other than the above aspect may be used.

As shown in FIG. 3, the wing 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 equipped with. The signal receiving module 65 receives the acceleration signal (acceleration information) output from the acceleration sensor 40 and the rotation position signal (rotation position information) output from the rotation sensor 41. Further, the signal receiving module 65 receives valve information indicating the open / closed state of the plurality of on-off valves 28 from the on-off valve control unit 29. That is, the on-off valve control unit 29 controls the opening and closing of each on-off valve 28 and outputs steam valve information to the blade abnormality detection device 50.
The acceleration signal output from the acceleration sensor 40 and the rotation 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 wing abnormality detection device 50 executes a program stored in its own device in advance to execute a control unit 51, a valve information acquisition unit 52, an acceleration information acquisition unit 53, and a rotation position information acquisition unit 54. , Partial load determination unit 55, wing abnormality determination unit 56, wing identification unit 57, and alarm unit 58.
The control unit 51 controls other functional units provided in the analysis device.

The valve information acquisition unit 52 acquires the valve information received by the signal receiving module 65. That is, the valve information acquisition unit 52 acquires information on whether the plurality of on-off valves 28 are in the open state or the closed state, respectively.
The acceleration information acquisition unit 53 acquires the acceleration information received by the signal receiving module 65 together with the time. That is, the acceleration information acquisition unit 53 acquires a time series of acceleration information.
The rotation position information acquisition unit 54 acquires the rotation position information received by the signal receiving module 65 together with the time. That is, the rotation position information acquisition unit 54 acquires a time series of rotation position information.

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

When the partial load determination unit 55 determines that the steam turbine 2 is in a partial load state, the blade abnormality determination unit 56 determines that the first stage rotor blade is based on the time series of acceleration information acquired by the acceleration information acquisition unit 53. Determine if there is an abnormality in column 6.

That is, the abnormality determination unit compares the time series of the acceleration information of the steam turbine 2 in the normal state when no abnormality has occurred in the first stage rotor blade row 6 with the time series of the acceleration information acquired by the acceleration information acquisition unit 53. Then, it is determined whether or not the moving blade row 6 in the first stage is abnormal. The acceleration information in the normal state is the acceleration information of the steam turbine 2 detected in advance in the normal state. When the acquired acceleration information deviates significantly from the normal acceleration information, the abnormality determination unit determines that an abnormality has occurred in the first stage rotor blade row 6. For example, the abnormality determination unit determines a threshold value in advance based on the normal acceleration information, and when the acquired acceleration information exceeds the threshold value, determines that an abnormality has occurred in the first stage rotor blade row 6. You may.

When the blade abnormality determination unit 56 determines that the first stage rotor blade row 6 is abnormal, the blade identification unit 57 is the first stage rotor blade based on the rotation position information acquired by the rotation position information acquisition unit 54. The moving blade 7 in which the abnormality has occurred is identified from the row 6. That is, the blade identification unit 57 matches the time series of acceleration information with the time series of rotation position information. As a result, when the acceleration value of the acceleration information greatly deviates, the rotor blade 7 (the rotor blade 7 located in the steam inflow region S shown in FIG. 2) that is closest to the introduction port 26 is specified. I do. At the time of the calculation, information on which on-off valve 28 was in the 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 on-off valve 28 is in the open state at the time of partial load, it is assumed that steam is introduced from the specific introduction port 26 at the time of partial load, and the calculation for specifying the moving blade 7 may be performed. Good.

The alarm unit 58 outputs an alarm based on the calculation result of the blade identification unit 57. That is, when the blade specifying unit 57 identifies the moving blade 7 that is abnormal, the alarm unit 58 performs a process of outputting an alarm indicating that the 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 the alarm information on the 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 with reference to the flowchart shown in FIG. The blade abnormality detection method executes each of the valve information acquisition process S1, the acceleration information acquisition process S2, the rotation position information acquisition process S3, the partial load determination process S4, the blade abnormality determination process S5, the blade identification process S6, and the alarm process S7. To do.

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

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

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 described in the processing by the blade abnormality determination unit 56. Based on the time series of, it is determined whether or not there is an abnormality in the first stage rotor blade row 6.

The blade identification step S6 is performed after the blade abnormality determination step S5 and the rotation position information acquisition step S3.
In the blade identification step S6, as in the process of the blade identification unit 57, when it is determined that the first stage rotor blade row 6 is abnormal, the first stage is based on the rotation position information acquired by the rotation position information acquisition unit 54. The moving blade 7 in which the abnormality has occurred is identified from the moving blade row 6 of the eye.

Here, FIG. 5 shows a time series of waveforms of acceleration signals and rotation position signals during normal and abnormal conditions. Regardless of whether it is normal or abnormal, the acceleration signal shows a waveform that vibrates each time the rotor blade 7 passes through the introduction port 26 into which steam is introduced. In the normal state, as shown in FIG. 5A, the change in the amplitude of the waveform is small, but in the abnormal state, as shown in FIG. 5B, only a part of the amplitude of the waveform is larger than the other amplitudes. Deviate. This is because the abnormal moving blade 7 passed near the introduction port 26 into which steam was introduced. In the blade abnormality determination step S5, when the amplitude of a part of the waveform changes significantly as shown in FIG. 5 (b) with reference to the waveform of the normal acceleration in FIG. 5 (a), the first stage moving blade It is determined that an abnormality has occurred in any of columns 6. In addition, for example, when an amplitude exceeding the threshold value occurs with reference to the waveform of the acceleration at the normal time, it may be determined as abnormal. Further, the standard deviation for each amplitude may be obtained, and if the standard deviation exceeds the threshold value, it may be determined as abnormal.

Further, the rotation position signal shows the same waveform regardless of whether it is normal or abnormal. That is, the intensity peak of the rotation position signal appears for each rotation. Since the moving blades 7 are evenly provided in the circumferential direction, the rotational position of each moving blade 7 at an arbitrary time point can be derived based on the peak. In the blade identification step S6, the moving blade 7 in which the abnormality has occurred is specified by matching the acceleration signal and the rotation position signal at the time of abnormality. That is, when the peak appears in the acceleration, the moving blade 7 that is in a state close to the vicinity of the steam introduction port 26 is specified.
In the alarm step S7, an alarm is output based on the calculation result of the blade specifying unit 57, as in the process of the alarm unit 58.

Next, the operation and effect of the steam turbine system 1 of the present embodiment will be described.
When the steam turbine 2 is fully loaded, all the on-off valves 28 corresponding to the plurality of introduction ports 26 are opened, so that the working fluid is introduced from all the introduction ports 26. On the other hand, when the steam turbine 2 is partially loaded, only the on-off valve 28 corresponding to a part of the introduction ports 26 among the plurality of introduction ports 26 is opened, and the remaining on-off valve 28 is closed. As a result, at the time of partial load, the working fluid is introduced only from a part of the introduction ports 26.

At the time of such a partial load, the plurality of rotor blades 7 of the first stage rotor blade row 6 pass through the vicinity of the introduction port 26 into which steam is introduced in the circumferential region, and the exciting force due to the steam is generated. Will receive. That is, the first stage rotor blade 7 vibrates when it reaches the circumferential direction corresponding to the introduction port 26 into which steam is introduced.

Here, in the normal state where all the moving blades 7 of the first-stage moving blade row 6 are not deformed or damaged, the moving blades 7 passing near the introduction port 26 into which steam is introduced have a vibrating force due to steam. Vibrates in much the same way. That is, since the rigidity of all the moving blades 7 is almost the same, these moving blades 7 show the same vibration mode.
On the other hand, when any of the moving blades 7 in the first stage moving blade row 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 this decrease in rigidity, only the abnormal moving blade 7 vibrates more than the other moving blades 7. Therefore, the steam turbine 2 as a whole vibrates significantly only when the abnormal moving blade 7 passes near the introduction port 26 into which steam is introduced. As a result, the acceleration sensor 40 detects acceleration information indicating a peak before one rotation.

In the present embodiment, based on the above findings, the moving blade 7 in which the abnormality occurs in the moving blade row 6 in the first stage is specified. That is, when the partial load determination unit 55 determines that the steam is introduced only from one of the introduction ports 26 at the time of partial load, the first stage rotor blade row 6 is based on the acceleration of the steam turbine 2. Judge whether or not an abnormality has occurred in. Next, when it is determined that an abnormality has occurred, the moving blade 7 in which the abnormality has occurred is specified from the plurality of moving blades 7 based on the rotation position of the rotating shaft 4. Thereby, the abnormality of the moving blade 7 can be easily identified.

Further, since the acceleration sensor 40 is provided on the bearing base 15 of the steam turbine 2, that is, on the outer surface of the steam turbine 2, acceleration information can be acquired without being affected by the properties of the working fluid or the like. Can be done. Further, since the presence or absence of an abnormality is determined based on the peak of the acceleration indicated for each rotation as described above, it is difficult for the peak to be masked by other dark vibrations or the like. Therefore, the abnormality of the moving blade 7 can be detected with high accuracy.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and can be appropriately modified without departing from the technical idea of the 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. Further, it may be provided on the rotating shaft 4 or the like inside the casing 21.

Further, for example, in the embodiment, an 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.

1 Steam turbine system 2 Steam turbine 3 Rotor 4 Rotating shaft 5 Moving blade row group 6 Moving blade row 7 Moving blade 7a Shroud 8 Thrust bearing 9 Journal bearing 10 Bearing body 11 Bearing housing 15 Bearing base 16 Top surface 20 Stator 21 Casing 22 Static wing Row group 23 Static blade row 24 Static blade 25 Steam introduction unit 26 Inlet 27a Steam supply source 27b Steam line 28 On-off valve 29 On-off valve control unit 30 Wing abnormality detection system 40 Acceleration sensor 41 Rotation sensor 50 Wing abnormality detection device 51 Control unit 52 Valve information acquisition unit 53 Acceleration information acquisition unit 54 Rotation position information acquisition unit 55 Partial load judgment unit 56 Bearing abnormality judgment unit 57 Bearing identification unit 58 Alarm unit 61 CPU
62 ROM
63 RAM
64 HDD
65 Signal receiving module S1 Valve information acquisition process S2 Acceleration information acquisition process S3 Rotation position information acquisition process S4 Partial load determination process S5 Blade abnormality determination process S6 Blade identification process S7 Alarm process O Axis line S Steam inflow area

Claims (6)

A group of rotor blades having a rotating shaft rotating around an axis and a plurality of rotor blades extending radially from the rotating shaft in a plurality of stages in the axial direction, which is the flow direction of the working fluid, and the above. A plurality of introduction ports for introducing the working fluid into the first stage rotor blade row are provided in the circumferential direction of the axis, and a plurality of introduction ports are provided corresponding to each of the introduction ports while surrounding the rotor blade row group from the outer peripheral side. An on-off valve that opens and closes the flow path of the working fluid supplied to the introduction port, respectively.
It is a blade abnormality detection device of a rotating machine equipped with
An acceleration information acquisition unit that acquires acceleration information of the rotating machine,
A rotation position information acquisition unit that acquires rotation position information of the rotation axis,
A valve information acquisition unit that acquires valve information indicating the 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 out of the plurality of on-off valves is in the open state.
When the partial load determination unit determines that the partial load state is present, the blade abnormality determination unit determines whether or not there is an abnormality in the first stage rotor blade train based on the time series of the acceleration information.
When it is determined that the moving blades in the first stage are abnormal, a blade specifying portion that identifies the moving blades in which an abnormality has occurred from the moving blades in the first stage based on the rotation position information.
Wing anomaly detector with. The wing abnormality determination unit
Comparing the time series of the acceleration information of the rotating machine at the normal time when the moving blade row in the first stage is not abnormal and the time series of the acceleration information acquired by the acceleration information acquisition unit, the first stage The blade abnormality detecting device according to claim 1, wherein it is determined whether or not the moving blade train is abnormal. The wing abnormality detection device according to claim 1 or 2,
An acceleration sensor that detects the acceleration of the rotating machine and outputs it to the blade abnormality detection device,
A rotation sensor that detects the rotation position of the rotation shaft and outputs it to the blade abnormality detection device,
Wing anomaly detection system with. With the rotating machine
The wing abnormality detection system according to claim 3 is provided.
The rotary machine is a rotary machine system having 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 bearings that rotatably support the rotating shaft around the axis.
A bearing base that supports the bearing from below,
With
The rotary mechanical system according to claim 4, wherein the acceleration sensor is provided on the bearing base. A group of rotor blades having a rotating shaft rotating around an axis and a plurality of rotor blades extending radially from the rotating shaft in a plurality of stages in the axial direction, which is the flow direction of the working fluid, and the above. A plurality of introduction ports for introducing the working fluid into the first stage rotor blade row are provided in the circumferential direction of the axis, and a plurality of introduction ports are provided corresponding to each of the introduction ports while surrounding the rotor blade row group from the outer peripheral side. An on-off valve that opens and closes the flow path of the working fluid supplied to the introduction port, respectively.
It is a method for detecting blade anomalies of rotary machines equipped with
Acceleration information acquisition process for acquiring acceleration information of the rotating machine, and
The rotation position information acquisition process for acquiring the rotation position information of the rotation axis, and
A partial load state in which only some of the on-off valves out of the plurality of on-off valves are in the open state based on the valve information acquisition process for acquiring valve information indicating the open / closed state of the plurality of on-off valves and the valve information. Partial load judgment process to judge whether or not
When the partial load determination step determines that the partial load state is present, the blade abnormality determination step of determining whether or not there is an abnormality in the first stage rotor blade train based on the time series of the acceleration information, and the blade abnormality determination step.
When it is determined that the first-stage rotor blades are abnormal, a blade identification step of identifying the rotor blades in which an abnormality has occurred from the first-stage rotor blades based on the rotation position information, and
Wing anomaly detection method including.

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