JPH0470564B2 - - Google Patents

Description

[Detailed description of the invention] [Objective of the invention] (Industrial application field) The present invention monitors shaft vibration of rotating machinery such as a turbine generator in a power generation plant, and detects plant abnormalities early and analyzes their causes. The present invention relates to a vibration monitoring device for carrying out.

(Prior Art) Abnormalities in turbines, which play an important role in power generation plants, often manifest themselves as vibration changes in the rotor. Among such vibrations of the turbine rotor, the most typical vibration is due to mass unbalance, and it is said that half of the vibration problems can be solved if the rotor unbalance can be properly corrected. The vibration caused by this unbalance is a synchronous vibration whose vibration frequency is the same as the rotational speed of the rotor. Further, the maximum amplitude value of vibration and the direction (angle) at which the maximum amplitude is obtained are determined by the position and amount of unbalance, operating conditions such as the rotational speed at that time, and the measurement position and direction. Therefore, information regarding the position and amount of unbalance can be obtained by setting a reference point along with the amplitude value at a point on the circumferential direction of the rotor and detecting the angle from this reference point, that is, the phase angle, at each rotation speed. .

Therefore, a method of recording the locus on a polar coordinate graph as shown in FIG. 8 and observing its changes is adopted. In the figure, the radial direction represents the maximum amplitude value, and the circumferential direction represents the phase angle. In addition, the graph represents the trajectory when the rotation speed of the turbine rotor is increased, and the subscript number on the line represents the rotation speed. For example, 36 represents the trajectory of the maximum amplitude value at 3600 rpm and the phase angle from the reference point. It shows.

As shown in Figure 9, the measurement graph in which the maximum amplitude value and the phase angle from the reference point are expressed as vector components in polar coordinates can be expressed as Since a unique characteristic diagram can be obtained for each, pattern matching can be easily performed, and online vibration monitoring using a computer is performed using this polar coordinate display.

(Problem to be solved by the invention) However, conventional online vibration monitoring
They simply measure vibrations of the plant in a steady state or at a single point on a regular basis. on the other hand,
Vibrations due to unbalance are not limited to those caused by residual unbalance during the manufacture of the turbine rotor, but may also be caused by bending of the rotor over time, loss of parts associated with the rotor, and the like. In addition, when the load changes during normal operation or even under a constant load, the alignment of the rotor bearing changes due to thermal deformation, changes in the degree of vacuum, and changes in load, and unbalanced vibrations may be observed.

In this way, unbalanced vibrations are not only caused by the rotor itself, but can also be affected by operating conditions. There was a problem that plant abnormalities could not be detected early.

SUMMARY OF THE INVENTION Therefore, the present invention provides a vibration monitoring device that consistently monitors vibrations from plant start-up to stoppage, and allows operators to easily determine abnormalities during plant operation in order to discover abnormalities in the plant. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) The present invention monitors the shaft vibration of the turbine rotor constantly online from the start of the plant, and monitors the measured data according to the rotational speed of the plant or the state of the load. This data is stored as data, and when an operator makes a vibration monitoring request, a monitoring screen optimal for monitoring unbalanced vibration is created and displayed according to the state of the plant.

(Function) As a result, operators can easily perform pattern matching, easily perform abnormality determination at any time, and discover abnormalities in the plant at an early stage.

(Embodiment) FIG. 1 shows the configuration of a vibration monitoring device according to an embodiment of the present invention.

From plant 1, an alternating current signal a of shaft vibration synchronized with the turbine rotation speed detected by each detector installed in eight bearings from the first bearing to the eighth bearing of the turbine rotor, and A signal a' from the reference point is output to the vibration phase angle measuring device 2.
On the other hand, plant state data b such as the rotational speed and load of the turbine rotor is directly output from the plant 1 to the computer 3.

The vibration phase angle measuring device 2 has eight controllers corresponding to each bearing, and inputs an AC signal a of shaft vibration synchronized with the turbine rotation speed from the plant 1 and a signal a' from a reference point. As the maximum amplitude value and the phase angle of the maximum amplitude value of the input shaft vibration AC signal a, measure the angle from the reference point mentioned above at the same time on each axis at a constant period, and calculate the measured maximum amplitude value and phase angle. It is stored in internal memory. This internal memory stores up to 64 sets of data (hereinafter referred to as 3-set data) for each axis, including the maximum amplitude value, phase angle, and turbine rotation speed. It's summery.

This internal memory always stores 64 pieces of the latest three sets of data for each bearing and is updated cyclically. In addition, since the three sets of data stored in the vibration phase angle measuring device 2 receive transmission requests for each bearing, that is, each controller, the computer that issued the request cannot determine the simultaneity of the data between the bearings. When storing three sets of data for each bearing, identification numbers 1, 2, 3, . For example, at a certain point, the data is updated cyclically, and the three sets of data for a certain bearing are arranged in order from the top: 10, 11, ..., 63, 64, 1,
2,..., 8, 9, the identification number is 9.
The data with identification number 10 is the latest data, and the data with identification number 10 is the oldest data. However, for data between bearings with the same identification number, the computer side can determine the simultaneity by checking this identification number. I can do it. This identification number is hereinafter referred to as a synchronization ID.

The three sets of data stored in the internal memory of each vibration phase measuring device 2 are obtained from the computer 3 or another computer using the bearing number, number of data, and data as shown in Figure 2.
When a transmission request is received in a format in which each request parameter of a specified synchronization ident is set, it is sent to the requesting computer.

Among the requested parameters, the bearing number is a parameter for identifying the controller for each bearing, and the number of data items is a parameter for specifying the number of three sets of data to be requested for transmission. In addition, the specified synchronization ident is the synchronization ident mentioned earlier, and when this is specified, the specified number of three sets of data saved before that corresponds to the specified synchronization ident. It will be sent retroactively by that amount.

Further, if there are no three sets of data for the specified number of data going back in the past, only the amount of data that exists in the internal memory is sent going back from the specified synchronization ident. If this specified synchronization ident is not specified, the synchronization ident of the newest data is assumed to have been specified.

The computer 3 includes a transmission data input means 4 which inputs three sets of data from the vibration phase angle measuring device 2, and a data transmission device which outputs the format shown in FIG. 2 as a transmission command c to the vibration phase angle measuring device 2. A requesting means 5 is also provided. In addition, plant status data b from plant 1 is input to determine whether the turbine rotational speed is maintained, combined, or loaded, and the determination result is determined by setting a flag with a specific bit in a predetermined plant status setting table. It is provided with a rotation speed/load determining means 6 to output. It also includes a data storage means 7 for extracting and storing three sets of data input via the transmission data input means 4 at predetermined intervals based on the determination results of the rotation speed/load determination means. Also, when a monitoring request d from an operator is input, the three sets of data stored in the data storage means 7 are monitored according to the plant state at that time based on the judgment result by the rotation speed/load state judgment means 6. Monitoring screen creation means 8 for creating a screen for use
It is equipped with The monitoring screen data e created by the monitoring screen creating means 8 is output to a display device and displayed as a monitoring screen.

Further, the data transmission requesting means 5 of the computer 3 inputs the information regarding the three sets of data being transmitted from the transmission data inputting means 4 and the plant state determination results from the rotation speed/load state determining means 6, and receives the current information from the former. It determines which axis the three sets of data being transmitted relate to, and from the latter it determines whether to switch the number of data to be transmitted according to the plant status, sets request parameters and creates text according to the format shown in Figure 2. Transmission request parameter setting means 5A
and a transmission command output means 5B which receives the text from the transmission request parameter setting means 5A and outputs it as a transmission command c to the vibration phase angle measuring device 2 at a cycle of 10 seconds.

Further, the data storage means 7 sequentially inputs the three sets of data for each axis output from the transmission data input means 4, and stores the three sets of data for storage according to the plant state determined by the rotation speed/load state determining means 6. A storage data extraction means 7A for extracting the storage data extraction means 7A, and a state-specific data storage means 7 for storing the extracted data from the storage data extraction means 7A in a predetermined storage area.
B, and a data storage area 7C in which three sets of data are actually stored by this state-specific data storage means 7B.
It becomes more.

Further, the monitoring screen creation means 8 includes a monitoring screen output request receiving means 8A that inputs a monitoring request d from an external console, and a monitoring screen output request receiving means 8A that inputs a monitoring request d and determines the rotation speed and load state. Based on the plant status determined by means 6,
Monitoring data retrieval means 8B for retrieving three sets of data for displaying a predetermined monitoring screen (hereinafter referred to as monitoring data) from the data storage area 7C in the data storage means 7, and a fixed screen for monitoring. A fixed screen data storage area 8C for monitoring, and a fixed screen for monitoring is selected from this fixed screen data storage area 8C and displayed on the display device 9, and the monitoring data from the monitoring data extraction means 8B is displayed on the displayed screen. It consists of a monitoring screen output means 8D for displaying.

With the above configuration, the vibration phase angle measuring device 2 has the following functions in order to monitor unbalanced vibration of the turbine rotor:
Based on the shaft vibration alternating current signal a and signal a' synchronized with the turbine rotation speed input from plant 1, the maximum amplitude value of the eight bearings of the turbine rotor, its phase angle, and the rotation speed at that time are measured every second. do. At this time, the vibration phase angle measuring device 2 measures the AC signal a and the signal a' of shaft vibration from the detectors installed in each bearing at the same timing for all axes. The reason why all axes are measured at the same time is that vibration analysis of the turbine rotor requires vibration data for each bearing to be data at the same time.

The vibration phase angle measuring device 2 stores three sets of data of the amplitude value of the vibration, the phase angle, and the turbine rotation speed measured every second in the internal memory for each bearing. Also, the saved data can be updated cyclically.

While each vibration phase measuring device 2 is making such vibration measurements, the transmission request parameter setting means 5A in the computer 3 sets the request parameters shown in FIG. The number of data among the request parameters is
Data must be collected every 10 rpm during turbine speed increase and every 5 MW during load increase.
In order to collect data without omission during this period, 20 pieces of data are normally specified for each bearing during speed increase and load increase, taking into consideration the possibility that the cycle of transmission requests output from transmission command output means 5B may be delayed. do. Also, sometimes when the rotation speed or the load is being maintained, one per transmission request.
64 per bearing to see the change in data per minute
Specify the total memory contents for each controller. This switching of the number of data items is automatically performed by the rotation speed/load state determining means 6.

Now, the transmission request parameter setting means 5A is
After setting required parameters regarding the bearing and creating a text, the created text is output to the transmission command output means 5B. The transmission command output means 5B is
This is output to the vibration phase angle measuring device 2 as a transmission command c.

When the vibration phase angle measuring instrument 2 inputs the transmission command c, it decodes the text, treats the three sets of data and the corresponding synchronization ident as one piece of data, and outputs the specified number of data as shown in Figure 3. The data is output to the transmission data input means 4 in the computer 3 according to the format. The transmission data input means 4 is a first
When the three sets of data for the bearing are input, the synchronization identifier of the latest three sets of data among the input three sets of data is output to the transmission request parameter setting means 5A. When the transmission request parameter setting means 5A inputs the synchronization ident of the latest three sets of data regarding the first bearing, it sets this synchronization ident as the designated synchronization ident of the second bearing, sets the request parameter of the second bearing, and outputs the text. and outputs it to the transmission command output means 5B. The transmission command output means 5B outputs this to the vibration phase angle measuring device 2 as a transmission command c. As a result, the vibration phase angle measuring device 2
This time, in the same way as for the first bearing, it outputs three sets of data regarding the second bearing in the number specified by the synchronization identifier to the transmission data input means 4.

Hereinafter, the transmission request parameter setting means 5A uses the first synchronization ident of the first bearing and the specified number of data pieces in the same manner as for the second bearing.
Set the required parameters for the third to eighth bearings and create text. Transmission command output means 5B
sequentially outputs the created text as a transmission command c. The vibration phase angle measuring device 2 sequentially outputs three sets of synchronized data of each bearing to the transmission data input means 4.

This synchronized input/output operation of three sets of data from the first bearing to the eighth bearing is regarded as one transmission, and this is repeated every 10 seconds. Normally, it is rare to specify a specified synchronization ident for the first bearing, and three sets of data regarding the first bearing are sent every 10 seconds.
Only the specified number of data items will be input from the latest three sets of data. In this way, the transmission data input means 4 inputs three synchronized sets of data from the first bearing to the eighth bearing every 10 seconds.
The set data is outputted to the storage data extraction means 7A in the data storage means 7 together with the synchronization ident.

On the other hand, the rotation speed/load condition determination means 6 periodically inputs the plant condition data b, so that the plant maintains the intermediate rotation speed/rated rotation speed, joins the rotation speed, or maintains the initial load, low load, intermediate load, or rated load. It is determined which state of holding the plant is in, and a plant state table as shown in FIG. 4 is created.

The initial value of this plant status table is “0”
When it is determined that the turbine is in a predetermined operating state, the corresponding bit is set to "1" and a flag is set. After addition, the load is also read and recorded in the plant status table. The storage data extracting means 7A in the data storage means 7 refers to the current plant state table set by the rotation speed/load state determining means 6, and determines which of the following types the plant state belongs to. do.

CASE Turbine rotation speed is increasing CASE Turbine rotation speed is being maintained or load is being maintained after merging CASE Load is increasing If the plant status is CASE, the rotation speed is
Every 10rpm increase, in the case of CASE, there is no change in the turbine rotation speed or load, so it is based on time.
Save monitoring data every 60 seconds or every 5 _MW increase in load in case of CASE.

Therefore, when the plant status belongs to CASE, first check the rotation speed of the 3 sets of data.
Data extraction means 7 for saving 3 sets of data every 10 rpm
Extract by A. Next, the extracted three sets of data are stored for each bearing in the CASE area of the data storage area 7C by the state-specific data storage means 7B.

On the other hand, when the plant status belongs to CASE, the latest 3 sets of data of the input text are extracted when the load read by the rotation speed/load status determination means 6 changes by 5 _MW , and the data is used for monitoring every 5 _MW . Save each bearing as data in the CASE area.

Furthermore, if the plant state belongs to CASE, in order to save 3 sets of data every minute, look at the sync ident of the 3 sets of data extracted last time and have a sync id of (previous sync ident) + 60 (mod64). Find and extract three sets of data.
For example, if the synchronization ident of the 3 sets of data extracted last time is 10, the 3 sets of data to be extracted after 1 minute have passed.
The set data will be 10 + 60 = 70, but when mod64 is calculated, the one with a synchronization ident of 6 will be the 3 set data exactly 1 minute later, and this will be extracted. The three sets of data extracted in this way are saved in the CASE area for each bearing.

In particular, in the case of CASE, if the phase angle changes significantly over a period of one minute, it is considered valuable data for detecting abnormalities, so for example, if a change of 10°/sec or more appears, the data during that time will also be extracted. It is designed to do so.

In this way, newly extracted monitoring data for each plant state and each bearing is successively stored in the data storage area 7C. At this time,
In the case of CASE, in order to grasp the current collection status of monitoring data at a glance, an information record for determining the collection status is set as shown in FIG. 5a, and the information record is updated as the collection progresses. This is to facilitate the management of saved monitoring data. For example, in the case of CASE, monitoring data every 10 rpm is
Each data is grouped into one group and saved as monitoring data as shown in FIG. 5b. In addition, in the case of CASE, 10 pieces of monitoring data for every 5 _MW are saved as one group, and in the information record, the data collection status is monitored every 50 _MW , and 10 pieces of data are saved for every 5 _MW . When all the information is collected, set a flag corresponding to each information record. In this way, data management
The reason why this is done every 50 _MW at 100 rpm is to take into consideration the frequency at which data is updated on the monitoring screen.
Data corresponding to CASE has a long monitoring data collection cycle of one minute, so it is managed every minute.

Now, when the operator inputs the monitoring request d, the monitoring screen output request accepting means 8A in the monitoring screen creating means 8 outputs the bearing number specified by the operator to the monitoring data extracting means 8B. The monitoring data retrieval means 8B first determines the plant state at that time based on the plant state table set by the rotation speed/load state determining means 6, and determines the monitoring data regarding the bearing number specified according to the plant state. Extract data. Monitoring screen output means 8D
is the CASE and CASE monitoring data display screen A or CASE and CASE stored in the fixed screen data storage area 8C according to the monitoring data retrieved by the monitoring data retrieval means 8B.
Select one of the screens on which the two polar coordinate graphs of the monitoring data display screen B are displayed and display it on the display device 9. The combination of monitoring screen and monitoring data selected at this time is shown in FIG. If the plant status is before annexation, CASE monitoring data is retrieved and screen A is selected. The extracted CASE monitoring data is plotted on one polar coordinate graph of the displayed screen A. If the plant state is that the rotational speed is being maintained, CASE monitoring data is extracted in addition to CASE data, screen A is selected, and the respective monitoring data are plotted on two polar coordinate graphs. Also, if the plant status is load holding, CASE and CASE
The monitoring data is extracted, screen B is selected this time, and the respective monitoring data are plotted on two polar coordinate graphs.

Next, FIG. 7 shows a specific example of a monitoring screen when maintaining a constant rotation speed and path number. This is an example of screen A, and the polar coordinate graph on the left is based on time.
This is a graph of CASE, in which the maximum amplitude value and phase angle are plotted every 10 minutes. In the figure, T-V
is an abbreviation for Time-Vibration. The polar coordinate graph on the right is based on the turbine rotation speed.
This is a graph of CASE, in which the maximum amplitude value and phase angle are plotted at every 500 rpm. In the figure, S
-V is an abbreviation for Speed-Vibration. The data values for each plot point are displayed in a table at the bottom right of each polar coordinate graph. Also, the bearing number is displayed at the top left of the screen.
is also displayed.

After this screen A is displayed, new monitoring data to be saved in the data storage area 7C will be periodically referenced to the information record in the data storage area 7C until the monitoring request is canceled by the operator. The updated data is retrieved by the monitoring data retrieval means 8B which reads the updated data each time the data is updated, and is displayed on the monitoring screen each time. This allows the operator to monitor unbalanced vibrations of the designated turbine rotor in real time.

As described above, according to this embodiment, since vibration monitoring data is collected consistently from the time the plant is started up, an operator can request monitoring at any time to detect the shaft vibration of the turbine rotor from the time of data collection. can be monitored. Moreover, since the monitoring screen is switched according to the plant status, pattern recognition becomes easy, abnormality determination can be easily performed, and plant abnormality can be discovered at an early stage.

In addition, in this embodiment, the load-based monitoring screen is automatically selected after the combination, but even after the combination, the monitoring screen when the rotation speed is increasing can be selected so that it can be displayed as historical data. Functions may be added. This allows you to not only perform online monitoring on a temporary basis, but also to freely pull out collected data at any time, increasing your vibration analysis capabilities.

In addition, in order to make abnormality detection even easier,
The average normal pattern in the plant may be determined, stored in a database, and the standard normal pattern may be displayed simultaneously with the monitoring screen of this embodiment. Thereby, the operator can more easily perform pattern matching with the normal pattern, and can more quickly and accurately detect vibration abnormalities.

[Effects of the Invention] As described above, according to the present invention, it is possible to monitor the shaft vibration of the rotor online after starting the plant, and when a monitoring request is made by an operator, the vibration can be monitored according to the plant status. Since a monitoring screen with easy pattern matching is created, a vibration monitoring device that can easily perform abnormality determination and discover plant abnormalities at an early stage can be obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a vibration monitoring device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a text transmitted from the transmission command output means of FIG. 1, and FIG. 3 is a vibration phase angle measuring device of FIG. 1. FIG. 4 is an explanatory diagram of the format of the data sent from the plant, and FIG.
Figure a is an explanatory diagram of the monitoring data storage information table that is set when the status-specific data storage means in Figure 1 saves monitoring data, and Figure 5 b is an explanatory diagram of the monitoring data storage information table that is set when the status-specific data storage means in Figure 1 saves monitoring data. Data explanatory diagram, 6th
The figure is an explanatory diagram of the combination of monitoring screen and monitoring data.
FIG. 8 is an explanatory diagram of the display of the monitoring screen, FIG. 8 is an explanatory diagram of polar coordinate display of amplitude and phase of vibration, and FIG. 9 is an explanatory diagram of an example of a pattern of polar coordinate display due to unbalanced vibration. 1...Plant, 2...Vibration phase angle measuring device, 3
...Computer, 4...Transmission data input means, 5...
Data transmission request means, 5A...Transmission request parameter setting means, 5B...Transmission command output means, 6...
Rotation speed/load condition determination means, 7...Data storage means, 7A...Saving data extraction means, 7B...Status-specific data storage means, 7C...Data storage area,
8...Monitoring screen creation means, 8A...Monitoring screen output request receiving means, 8B...Monitoring data retrieval means, 8C...Fixed screen data storage area, 8D...
Monitoring screen output means, 9...Display device.

Claims (1)

[Scope of Claims] 1. The vibration amplification value and phase angle according to the rotational speed are periodically read from a vibration detector that measures the shaft vibration of the rotor disposed in the bearing part of the rotating machine, and the maximum of the vibration is determined. a vibration phase angle measuring device that stores and updates the amplitude value, the phase angle of the maximum amplitude value from a reference point, and the rotational speed at that time in an internal memory; and a rotational speed/angle measuring device that determines the rotational speed and load condition of the rotor. load condition determination means; data transmission request means for requesting the vibration phase angle measuring device to transmit measurement data; transmission data input means for reading data transmitted from the vibration phase angle measuring device;
data storage means for editing and saving the data read by the transmission data input means according to the plant state determined by the load state determination means;
A monitoring screen for creating a vibration monitoring screen by determining display contents of data for vibration monitoring according to the rotational speed and load condition of the rotor, extracting appropriate data from data stored by the data storage means; A vibration monitoring device comprising a creation means and a screen display device for displaying a vibration monitoring screen created by the monitoring screen creation means. 2. In the scope of claim 1, the monitoring screen creation means is configured to generate a monitoring screen every time the rotational speed increases by a certain amount when the rotating machine is speeding up, and when the rotational speed and load are constant and the rotating machine is maintained. The vibration monitoring device is characterized in that data is extracted from the data storage means at fixed time intervals, or every fixed load increase when the load of the rotating machine is increasing, and creates a corresponding monitoring screen.