JP2924328B2 - Turbine simulation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simulation device for simulating the operating state of a turbine.

[0002]

2. Description of the Related Art When designing a steam turbine, it is necessary to keep the shaft vibration within a limit value at the rated speed of the turbine or the critical speed of the rotor shaft system. However, at present, the calculation of the shaft vibration when the starting condition is variously changed is not performed. Therefore, conventionally, a mechanical running test for actually confirming the operation state of steam passing through the turbine was performed to measure the shaft vibration, and it was confirmed whether or not the shaft vibration at the measurement point was within the limit value.

[0003]

However, the above mechanical running test is performed under conditions different from actual steam conditions (steam temperature and steam pressure) and steam turbine support conditions (basic rigidity) due to the limitations of test facilities. It is, because it is limited also measured point of the shaft vibration, whether axial vibration at each part of the turbine rotor is within the limit value did not know.

Also, the mechanical running test has a problem that a large amount of cost (fuel cost, test cost) and test time are required. Further, when the size of the steam turbine increases, the equipment for performing the mechanical running test also needs to be large, so that it is difficult to perform the test itself.

[0005] An object of the present invention is to provide a simulation device capable of simulating an operating state of a turbine by changing various start-up conditions.

[0006]

According to the first aspect of the present invention,
Design data required for simulation of turbine shaft vibration
Design data storage means for storing the
Of the turbine and the inside of the turbine
Start-up curve data indicating the temporal change in temperature
Start curve data storage means,
Start from data showing data deformation and start curve data
An angle due to thermal deformation of the rotor at any point on the curve
Calculating means for calculating balance data;
Unbalance data of bearings and bearings during assembly
Alignment error data during assembly, which indicates the axis
Unbalun due to thermal deformation of the rotor calculated by the output means
Data from startup to normal operation based on the
Prediction means for predicting shaft vibration of the motor.

[0007]

[0008]

According to the simulation apparatus of the present invention, the shaft vibration of each part of the turbine from the start of the turbine to the steady operation can be obtained by calculation, so that the turbine is operated under the same conditions as the actual operating conditions. It can be confirmed whether the shaft vibration is within the limit value. Further, by changing the simulation conditions variously, it is possible to obtain the shaft vibration under conditions that cannot be tested during the actual operation, and it is possible to further improve the operation reliability of the turbine.

Furthermore, since a mechanical running test is not required, test cost and test time can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a system configuration diagram of the simulation device according to the embodiment of the present invention.

In FIG. 1, a mouse 11 and a Japanese keyboard 12 are used to input commands for selecting a simulation item, storing data, and outputting a result to an output device. The disk 13 and the magnetic tape device 14 store design data, various calculation programs described later, calculation results thereof, and the like. Color hard copy 1
5. The color display 16, the plotter and the laser printer 17 are for displaying or storing simulation results. The CPU 18 executes various calculation programs to simulate the steam turbine and controls the operation of each device described above.

Next, FIG. 3 is a diagram showing an overall flowchart of a calculation program executed by the simulation apparatus. The simulation programs can be broadly divided into shaft vibration response calculation programs, stability limit calculation programs, bearing metal temperature calculation programs,
Radial gap calculation program, life calculation program 5
Can be divided into two.

First, the shaft vibration calculation program will be described. The overall flowchart of shaft vibration calculation is as shown in Fig. 4. The shaft vibration is calculated by the shaft vibration response program from the unbalance amount due to heat stability, residual unbalance of a single unit, and the bearing load by assembly alignment and hot alignment. doing.

First, a hot alignment calculation program for obtaining hot alignment data affecting the bearing load will be described with reference to the flowchart of FIG. Hot alignment means that the bearing base thermally expands due to radiation and heat conduction from the high temperature part of the turbine casing, causing the height of the bearing part to be displaced. The displacement of the shaft center of the rotor occurs due to the displacement of the height of the portion. If the bearing height is displaced, the bearing load becomes non-uniform and causes shaft vibration.

In step S1 of FIG. 5, it is determined whether or not to consider hot alignment. When the hot alignment is considered, the start mode data of the turbine is read in the next step S2. Here, the start mode data indicates a state at the start of the operation of the turbine, and is a cold start that is started after the turbine is stopped for a long period of time, or a worm that is started after the turbine is stopped for a certain time (for example, during a weekend). This is data indicating which conditions of the start and the hot start in which the nighttime operation is stopped and the daily operation is started to start the turbine.

Next, in step S3, the counter I is sequentially incremented to read a predetermined number of start curve data from the start curve data of the turbine. Here, the startup curve data indicates a continuous change pattern with respect to time, such as the rotation speed, output, main steam temperature, and reheat steam temperature of the turbine at the time of startup, as shown in FIG.

Next, in step S4, hot alignment data Fb (t, T) at time I and bearing number J
And hot alignment data Fc for concrete columns
(T, T) are obtained, and they are added to calculate hot alignment data X (I, J) of the bearing portion. Note that F
b (t, T) and Fc (t, T) are functions of time t and temperature T, and represent hot alignment data due to thermal expansion of the bearing stand and hot alignment data due to thermal expansion of the concrete column, respectively.

In step S5, it is determined whether or not the value of the counter I is smaller than the number of data of the start curve data to be read. If the value of the counter I is smaller than the predetermined number of data, the process returns to step 3 and returns to step 3. The data at the next sampling point t is read.

After starting curve data for a predetermined number of data has been read, a hot alignment data file X (I, J) is created from those data in step S6. If the condition is set such that hot alignment is not considered when setting the simulation conditions, the determination in step S1 is NO, and the hot alignment data X (I, J) becomes "0" in step S7. As a result, the effects of the hot alignment can be removed, and the simulation of the shaft vibration by other elements can be performed.

Incidentally, there is another alignment at the time of assembling as another factor which affects the bearing load. This is not always the case when the turbine is actually assembled at the designed bearing height, and a certain degree of misalignment of the rotor axis occurs due to assembly errors. Therefore, a certain alignment error which is considered to be likely to occur at the time of assembling is given, and it is simulated whether or not dangerous vibration occurs in the turbine rotor due to the alignment error.

Although not shown, the assembling alignment calculation program is a process for creating an assembling alignment data file including alignment error data that may occur in each rotor when the turbine is installed.

The alignment data obtained by the hot alignment calculation program and the assembling alignment calculation program are converted into bearing load data by the preprocessing program shown in FIG.

Next, a heat stability data calculation program for obtaining heat stability weight data affecting the unbalance amount of the rotor will be described with reference to the flowchart of FIG.

Under high temperature conditions, the rotor may bend in a certain direction due to the metal structure of the turbine rotor or the non-uniformity of the heat treatment. This may cause an imbalance, and the vibration of the rotor may change during operation. . The heat stability is obtained by replacing the bending of the rotor determined by the steam temperature with an equivalent unbalance amount on the rotor using shaft bending data obtained during heat treatment.

In step S8 of FIG. 7, it is determined whether or not heat stability is to be considered. When heat stability is taken into account, the amplitude and phase angle data of the heat stability data of each rotor are read in the next step S9.
In this embodiment, since the number of rotors is six and the unbalanced surface is three, three amplitude data A and three phase angle data θ are obtained for each rotor. Note that the amplitude A
(6,3) and the phase angle θ (6,3) indicate the amplitude A and the phase angle θ on the three unbalanced surfaces of each of the six rotors.

In the next step S10, start-up mode data of the turbine is read, and in step S11, steam temperature data and the like at each sampling point of the start-up curve are read.
In step S12, for each of the three amplitude A and phase angle θ data of the six rotors, the data is multiplied by the inverse matrix α ⁻¹ of the influence coefficient α that connects the amplitude and the weight, and the weight The balance data W (I, J) is calculated.

Then, in step S13, a file of the heat stability weight data W (I, J) is created. If a condition is set such that heat stability is not taken into account when setting the simulation conditions, the determination in step S8 becomes NO, and the process proceeds to step S14.
, The heat stability weight data X (I, J) becomes “0”, and the effect of heat stability is removed.
Simulation of shaft vibration by other elements can be performed.

Next, FIG. 8 shows a program for converting the single residual unbalance data into the weight unbalance data. In the process of manufacturing a turbine rotor, the balance of each rotor is measured using a balance machine, and the balance is adjusted so as to be within an allowable vibration value. But,
In practice, the residual unbalance of the individual rotors does not become zero, and depending on the position of the residual unbalance, vibration may increase when a plurality of rotors are combined to assemble the turbine.

Therefore, in this program, the unbalance data of each rotor and its angle are obtained from the actual measurement data measured by the balance machine, and the influence of the vibration due to the residual unbalance of the rotor can be calculated.

In step S15 in FIG. 8, it is determined whether or not consideration is given to the residual unbalance of a single substance. When considering the single residual unbalance, the amplitude and phase angle data indicating the residual unbalance of each rotor measured by the balance machine are read in step S16. Then, step S17
Then, the amplitude data at three points of the six rotors is multiplied by an inverse matrix α ⁻¹ of an influence coefficient α linking the amplitude and the weight. Then, in step 18, a data file of the weight imbalance data W (I, J) at each position of the rotor is created.

If the condition for not considering the residual unbalance of a single unit is set when setting the simulation conditions, the determination in step S15 becomes NO, and the weight imbalance data W (I,
J) becomes “0”, and the simulation can be performed by removing the influence of the residual unbalance.

Next, the forced imbalance calculation program will be described with reference to the flowchart of FIG. During the operation of the turbine, the turbine blades break and the vibration changes suddenly, and the rotating body and the stationary part come into contact with each other in places where the clearance between the rotating body and the stationary part is small, such as the seal part of steam, causing friction. The shaft may be bent by heat, and the vibration state may change. Therefore, in the forced unbalance calculation program, an unbalance amount is forcibly added to a specific portion of the rotor, and a simulation is performed to determine whether the unbalance amount causes a significant vibration change in the turbine.

In step S21 of FIG. 9, it is determined whether or not forced imbalance is considered. If forced imbalance is taken into account, the weight and phase angle data of a specific paragraph is read from the forced imbalance data file in step S22.
Here, the forced unbalanced data file stores the weight and phase angle data of each paragraph when the rotor is divided into a large number of paragraphs. Therefore, in step S22, the three data obtained by other calculation programs are used. Weight and phase data on the unbalanced conversion plane are read.

In the next step 23, a file is created from the data read in step 22, which is composed of forced unbalanced data on three unbalanced conversion planes of each rotor.

If the conditions for not considering the imbalance data are set when the simulation conditions are set, the determination in step 21 is NO, and the process proceeds to step 24 where the weight amount data WI (I, J), “0” is set to the phase angle data θI (I, J). As a result, it is possible to perform the simulation while removing the influence of the forced imbalance data.

Next, the miscoupling calculation program will be described with reference to the flowcharts of FIGS. 10 (a) and 10 (b). Each rotor is connected by a coupling, but the center runout and surface runout of the coupling due to a variation in processing of the coupling itself, or the center runout and surface runout due to an error in assembling the coupling occur. Therefore, in the miscoupling calculation program, the center runout and surface runout are converted into equivalent unbalanced amounts.

In step S25 of FIG. 10A, the center runout and surface runout of the coupling are read from the position data of the coupling portion, the coupling processing data file and the coupling assembly data file, and the data is read in the next step S26. Create the file miscup.

Next, in step S27 of FIG. 10B, the center runout and surface runout are read from the data file.
In the next step S28, the shaft deflection amount calculation subroutine program is executed to convert the center runout amount and the surface runout amount into shaft deflection amount data, and further, the unbalance amount calculation subroutine program is executed, and the shaft deflection amount is converted into the unbalanced amount data. Convert to Thereafter, an unbalanced amount data file due to miscoupling is created based on the calculated unbalanced amount data.

Next, a program for calculating total unbalance data from unbalance amount data due to heat stability, residual unbalance of a single substance, forced unbalance, miscoupling, and the like will be described with reference to the flowchart of FIG.

First, in step S31 in FIG. 11, the heat stability calculation program in FIG. 7 is executed to read the amplitude and phase angle data based on the heat stability. Further, in the next step 32, the amplitude and phase angle data are converted into weight and phase angle data.

In step S33, weight and phase angle data are read from the forced imbalance data file created by the forced imbalance calculation program shown in FIG. Step S3
At 4, the weight and phase angle data are read from the residual unbalance data file created by the residual unbalance calculation program of FIG.

In step 35, the miscoupling calculation program shown in FIG. 10 is executed to read the center runout and surface runout data from the coupling processing data file. further,
In step S36, the center runout and surface runout data are converted into weight and phase angle data.

In step S37, the miscoupling calculation program shown in FIG. 10 is executed to read the center runout and surface runout data from the coupling assembly data file. Further, in step S38, the center runout and surface runout data are converted into weight and phase angle data.

In step S39, these weight data are added to obtain unbalance data on the unbalance conversion surface of each rotor. In step S40, the total unbalanced data files SUMS and SUPS are obtained from the above addition result.
Create

When the total unbalance data is obtained in this way, the bearing loads due to hot alignment, assembly alignment and the like are calculated, and the calculation results are output to the shaft vibration response program.

Although the shaft vibration response program is not specifically shown, it is a modification of a part of the existing shaft vibration calculation program.
Based on startup curve data where the steam temperature, rotation speed, output, etc. change over time, determine the bearing load and unbalance amount due to hot alignment, heat stability, etc., and simulate the shaft vibration in an unsteady state from those data The point is that we can do it.

Next, a program for calculating the temperature of the bearing metal supporting the rotor will be described with reference to the flowchart of FIG. In step S41 of FIG. 12, the load applied to the bearing metal is calculated from the assembling alignment data and the assembling alignment calculation fixed data. Here, the fixed data for alignment calculation at the time of assembly is an influence coefficient indicating how much the displacement of the bearing height at the time of assembly affects the load. Then, in the next step S42, the calculation result of the bearing load by the alignment at the time of assembly in each bearing is output.

[0048] In step S43, the data for instructing whether to calculate the startup curve data and what minute interval by the activation curve reading program, N points, i.e. O
-At time of bar speed, at no-load rating, at 50% load, at the rated load, at rating, at the inflection point and at several minute intervals, read the time and panula variables. Here, the panula variable is a value represented by: panula variable = rotation speed at time t / rated rotation speed + load / rated load at time t. From this value, the current operating state is used to determine which position on the startup curve. You can see if there is.

In step S44, it is determined whether the calculation of the bearing loads of the eight bearings NO1 to NO8 has been completed. 8
If the calculation of the bearing loads of the individual bearings has not been completed, in the next step S45, the fixed data for calculating the bearing metal temperature such as the shape of the bearing and the physical properties of the lubricating oil are read.

Then, in a step S46, it is determined whether or not the calculation of the bearing load is completed for the N points on the starting curve. If the calculation for N points is not completed,
In the next step S47, the fixed data for hot alignment calculation is read. Note that the fixed data for hot alignment calculation is an influence coefficient indicating how much displacement of the bearing height due to hot alignment affects the bearing load.

Next, in step S48, a change in bearing load due to hot alignment is determined using the hot alignment calculation program shown in FIG. Next, step S
At 49, the total bearing load is calculated by adding the bearing load by the alignment at the time of assembly and the bearing load by the hot alignment obtained at the step S42.

Further, in step S50, each bearing metal temperature is calculated from the bearing load of each bearing and the fixed data for calculating the bearing metal temperature. Then, Step S51
The metal temperature of each bearing obtained by the calculation is displayed.

Through these processes, it is possible to confirm whether or not the metal temperature of each bearing at each point on the starting curve is lower than the limit value. At this time, by changing the starting curve data, it is possible to confirm whether the bearing metal temperature falls within the limit value under various starting conditions.

Next, the thrust metal temperature calculation program will be described with reference to the flowchart of FIG. The thrust metal is a metal that regulates the axial movement of the turbine rotor.

In step S52 of FIG. 13, a panula variable for an arbitrary time t is obtained from the start curve data. Step S
At 53, the N points on the starting curve are read by the starting curve reading program, that is, at the time of overspeed, at the time of no load rating, at the time of 50% load, at the time of reaching the rated load, at the time of rating,
Read the time and panula variables at each point of the inflection point and the points in minutes.

In the next step S54, the fixed data for thrust metal temperature calculation is read. In step S55, it is determined whether or not the calculation of the thrust bearing load for the N points of the starting curve has been completed. If the calculation of the bearing load for N points has not been completed, in the next step S56, the fixed data for thrust bearing load calculation including the fixed data such as the shape of the bearing and the physical properties of the lubricating oil is read. In step S57, the thrust load at each point is calculated. further,
In step S58, the thrust metal temperature is calculated from the thrust bearing load calculation fixed data and the thrust load data at that point. Then, the thrust metal temperature calculated in step S59, the limit value of the thrust metal temperature, and the like are displayed on the display.

Through these processes, the thrust metal temperature at each point on the starting curve can be confirmed, and further, whether or not the temperature is within the limit value can be confirmed. Next, the stability limit calculation program will be described with reference to the flowchart of FIG. Here, the stability limit is a limit rotation speed at which the turbine can be driven stably when the rotation speed of the turbine is increased. Pointing to state.

In step S61 of the stability limit calculation program shown in FIG. 14, the bearing load is calculated from the alignment data at the time of assembly and the fixed data for alignment calculation at the time of assembly by using the alignment calculation program at the time of assembly. In the next step S62, the total bearing load by the alignment at the time of assembly is output.

At step S63, when the starting curve reading program is used, when no load is rated, when the rated load is reached,
Read the time of 3 points at the rated time. Then, in a step S64, it is determined whether or not the calculation of the bearing loads of the eight bearings NO1 to NO8 is completed. If the calculation of the load of the eight bearings has not been completed, the fixed data for stability limit calculation including the fixed data such as the shape of each bearing and the physical properties of the lubricating oil are read in step S65.

Further, at the time of no-load rating in step S66,
At the time of reaching the rated load, it is determined whether or not the calculation of the bearing load at each time of the rated time has been completed. If the calculation of the three points has not been completed, the fixed data for the hot alignment calculation, that is, the influence coefficient when converting the bearing displacement into the bearing load is read in step S67. In the next step S68, the change amount of the bearing load due to the hot alignment is calculated by the hot alignment calculation program of FIG.

Further, in step S69, the total of the bearing loads is obtained by adding the bearing loads by the alignment at the time of assembly and the hot alignment. Then, in step S70, from the bearing load and the fixed data for calculating the stability limit, the rotation speed at which the bearing can be rotated stably by applying a load equal to or more than a certain value is calculated.

Thereafter, the rotation speed at the stability limit obtained by calculation in step S71 is displayed on the display. Through these processes, the stability limit at each point on the starting curve can be confirmed, and it can also be confirmed whether the rotational speed at each point has a margin with respect to the stability limit.

Next, a program for calculating the elongation and the elongation difference between the rotor and the casing and the radial gap is shown in FIGS.
This will be described with reference to the flowchart of FIG. FIG. 15 and FIG.
6 represents one program divided and represented.
15 to FIG. 16 lead to.

The calculation result of the shaft center movement amount shown in FIG. 15 is a calculation result of the shaft center movement amount by a shaft center movement amount calculation program (not shown), which is the lift amount of the turbine rotor due to the change of the oil film thickness of the bearing portion. Is calculated. The axial center movement amount calculation result, the shaft vibration calculation result by the above-described shaft vibration calculation program, the main stage correspondence table indicating the calculation locations in these programs, and the reference distance are shown in FIG. Output to vibration addition program.

The rotor elongation coefficient, blade length, and average expansion rate shown in FIG. 15 and the rotation speed and load data with respect to time shown in FIG. 16 are obtained by using the FETE program for the rotor shown in FIG. Program) and F
In the ETE, the elongation of the blade due to thermal expansion and the elongation of the blade due to centrifugal force during rotation are calculated.

The initial metal temperature calculation program shown in FIG. 15 includes start mode data indicating whether the state at the time of start is a cold start, a warm start, or a hot start, the elapsed time since the operation was stopped, and the start. A post-disconnection time and a mode correspondence table showing the correspondence with the mode,
The initial temperature of each bearing is calculated from the node correspondence table indicating the position of each element when the bearing metal is divided into a plurality of elements, and the calculation result is output to the calculation control file of FIG.

The input data creation program shown in FIG. 16 includes pressure, temperature, and output data at time t on the startup curve, fixed values indicating turbine efficiency and the like, control stage state quantities, and the like.
From the no-load output correspondence table showing the mechanical loss at no load,
Input data for calculating the steam temperature and pressure for each time and place is created by a partial load calculation program described later.

The partial load calculation program is a program for calculating the steam temperature and pressure for each time at a specific place, and the calculation results are output to a post-processing program.
In the post-processing program, the steam temperature and pressure of each stage of the rotor and casing are calculated from the steam temperature and pressure of a specific stage (place) obtained by the partial load calculation program and the stage correspondence table. Output to condition creation program.
Through these processes, the steam temperature and pressure at any time on the rotor and the casing are determined.

Next, in order to determine the heat transfer coefficient of each part of the rotor and the casing, each stage for each time is determined by linear interpolation based on the relationship between the panula variable and the time as shown in FIG. The heat transfer coefficient is determined. Here, the heat transfer coefficient is determined by the panula variable because the heat transfer coefficient is affected by the flow velocity of steam flowing into the turbine, and so the heat transfer coefficient of each part is determined from the number of rotations and load that affect the flow velocity. It is.

Then, a correspondence table of the heat transfer coefficient of each stage for each time is output to the boundary condition creation program. Here, the step is a radially sliced one when the rotor and casing are divided into a plurality of finite elements in the FETE program.
Each block indicates one block, and one step is constituted by a plurality of elements at the same node position. By these processes, the heat transfer coefficient of an arbitrary stage of the rotor and the casing is obtained.

The boundary condition creation program is a program for converting the steam temperature, pressure, and heat transfer coefficient at any time of the rotor and the casing obtained by the above-mentioned program so as to conform to the input format of the FETE program. The converted data is output to the calculation control file.

The FEM fixed value is a fixed value indicating the shape of the turbine and is output to the calculation control file. The pressure / displacement correspondence table is data indicating how much displacement occurs when pressure is applied to each part of the turbine, and this correspondence table is output to the casing FETE program.

The steam flowing into the inside of the turbine is cooled by driving the load, and a part thereof becomes water and accumulates in the lower part of the casing. As a result, a temperature difference occurs between the upper part and the lower part of the casing, and the temperature difference causes the casing to warp, so that the radial gap with the rotor is not uniform. Therefore, the upper and lower temperature difference data and the shape data for calculating the upper and lower temperature difference are output to the FETE program for casing (a finite element program for calculating the displacement of the casing), and the casing is calculated by the upper and lower temperature difference calculation program inside the FETE. Is calculated.

Next, in order to calculate the thermal expansion of the stationary blade and the displacement due to the centrifugal force during rotation, the stationary blade expansion coefficient, the average expansion coefficient, and the stationary blade length data are output to the casing FETE program. In the rotor and casing FETE programs, the displacement due to thermal expansion and the displacement due to centrifugal force of each part of the rotor and casing are calculated based on the steam temperature, pressure and heat transfer coefficient of each part of the rotor and casing in the calculation control file at each time. Is calculated.

The shaft center movement amount and shaft vibration addition program calculates the shaft center movement amount calculation result and the shaft vibration calculation result by using the rotor FET
This is a program for calculating the rotor displacement in consideration of the axial center movement amount and the shaft vibration by adding to the rotor displacement obtained by the program.

By the way, when the calculation result of the axial movement amount and the calculation result of the shaft vibration are added to the calculation result of the FETE program by the above program, the calculation method of the axial movement amount
Since the calculation time and calculation location of each program of the shaft vibration calculation program and the above-mentioned elongation / elongation difference and radial gap calculation programs do not match, it is necessary to calculate the axial elongation and the radial gap in consideration of all their effects. Needs to match the calculation time and calculation location of each program.

Therefore, in the present embodiment, the calculation time and the calculation location of each of the above programs are made to match each other so that the displacement of an arbitrary location and time can be calculated. FIG. 18 is an explanatory diagram of a method for increasing the time. Hereinafter, an example will be described in which the calculation time and location of the bearing metal temperature calculation program are made to match the calculation time and location of the elongation / elongation difference and the radial gap calculation program.

Time t of the bearing metal temperature calculation program
_{m-1, t m, t} V a calculation result of the bearing metal temperature in the _{m + 1 m-1, V} m, and V _{m + 1} (see FIG. 18). First,
Expansion or differential expansion, the calculation time T _n in the radial clearance calculation program checks corresponding to where the computation time of the bearing metal temperature calculation program. _{Then, t m <T n <t} m + 1 to become if there is time, bearing metal temperature time t _m at time T _n, the time t _{m + 1} of the calculated value V of the bearing metal temperature
_m and V _{m + 1} can be obtained by the following equation.

[0079] in _{V n = (V m + 1} -V m) × (T n -t m) / (t m + 1 -t m) -V m times as shown in FIG. 18 from the equation T _n it is possible to obtain the bearing metal temperature V _n.

If these calculations are repeated for each time T _i of the elongation / elongation difference and radial gap calculation programs, the calculation times of the two programs can be matched. If the distance data is used instead of the time in the above equation, the calculation locations of the two programs can be matched.

When the calculation times and locations of the respective programs of the bearing metal temperature calculation program, the shaft vibration calculation program, the elongation / elongation difference, and the radial gap calculation program are made to coincide with each other, the displacement obtained by each program is calculated. The addition is performed to determine the axial extension and the radial extension of the rotor and the casing.

In the above finite element program (FETE program), the axial elongation and the radial elongation are individually calculated for each part of the turbine. Therefore, in the differential elongation and radial elongation calculation program considering the fixed point,
Considering which line of each finite element is shared and fixed based on offset data and fixed point data,
The radial gap between the rotor and the casing is calculated.

Further, a predicted value of the radial clearance and the axial clearance inside the turbine is obtained from the dimensions of each part which can be measured in the process of actually assembling the turbine. Since these values indicate the actual axial clearance and radial clearance of the turbine before starting, these values and the above-described elongation and elongation,
From the calculation results obtained by the radial gap calculation program, a final axial clearance and a radial clearance are obtained and displayed on the screen.

The time, volume average temperature, surface temperature, and the like when the temperature difference (surface temperature-volume average temperature) becomes maximum for each finite element are obtained by the FETE program. In the program, the strain ε is calculated by the following equation.

Ε = β × (surface temperature−volume average temperature) × k (1 / (1−ν)) Then, the allowable number of repetitions N is obtained from the strain ε using a low cycle fatigue curve, and the life consumption due to the current strain ε 1 / N is calculated, the life consumption is accumulated, and the life consumption of the turbine is calculated.This life consumption program allows the user to know how much the turbine life has been consumed by operating the turbine. Expansion coefficient β, strain concentration coefficient k
Are provided as fixed data for life consumption calculation.

Next, FIGS. 19 to 22 are views showing an example of a menu screen displayed on the display in the simulation apparatus of the actual example. First, as shown in FIG. 19, as initial menus, “create database”, “select simulation item”, “register database”,
Each item of “End” is displayed.

First, “create database” is selected, and the conditions and calculation results that have already been set are read out to the database. Next, a simulation item is selected and a submenu item selection is called. In this state, for example, when the axis vibration is selected as the simulation item, the items of “change data”, “display screen”, “print out”, and “return to the previous screen” are displayed as shown in FIG. You.

Here, when "change data" is selected, "startup curve" is changed to "hot alignment during assembly".
Since items related to the shaft vibration calculation program up to this point are displayed, a simulation can be executed under various conditions by selecting an arbitrary item and setting data. At this time, if the start curve data is selected, the simulation of the turbine can be executed under various start conditions.

Similarly, if "bearing metal temperature" is selected as a simulation item, each item related to bearing metal temperature is displayed as shown in FIG. 21, and if "elongation / difference in elongation" is selected as a simulation item, , FIG.
Each item related to “elongation / difference in elongation” is displayed as shown in FIG.

On the menu screen of FIG. 22, when "screen display" is selected, a submenu of the screen display is called up, and "time-elongation / difference in elongation curve", "time-radial gap change curve", "radial gap" Items such as "display of entire change" are displayed. By selecting these items, the temporal change of the radial gap or the overall change of the radial gap between the turbine and the rotor can be displayed on the display.

When the simulation is completed,
By selecting “database registration” in the initial menu of FIG. 19, the simulation conditions and simulation results of this time can be registered in the database.

As described above, by sequentially selecting the items displayed on the menu screen, the simulation conditions are arbitrarily set and the calculation of the axial vibration, the calculation of the radial gap, and the like are executed. It can be displayed on the display together with the warning value, and the results can be registered in the database.

As described above, according to the above embodiment, it is possible to calculate shaft vibration, bearing metal temperature, stability limit, elongation / elongation difference, radial gap, and the like at an arbitrary location and at an arbitrary time of a steam turbine. Therefore, it is possible to simulate the operating state of the turbine in the unsteady state as well as in the steady state, and to confirm the operating reliability of the turbine under the same conditions as the actual operating conditions. This eliminates the need for a mechanical running test, thereby reducing test cost and test time.

Further, since the simulation conditions can be set arbitrarily, the operation state of the turbine is simulated under more severe conditions than the actual operation conditions, and the margin of the actual value of the turbine with respect to the rated value is determined. You can also check.

[0095]

According to the present invention, it is possible to determine the shaft vibration of each part of the turbine at each time on the starting curve, so it is checked whether or not the shaft vibration of the turbine falls within the limit value at the turbine design stage. can do. In addition, since a mechanical running test is not required, test cost and test time can be reduced. Furthermore, since the simulation conditions can be set arbitrarily, it is possible to predict the shaft vibration under extreme conditions that are unlikely to actually occur but have extremely dangerous results when they occur, so that it is possible to predict by simulation. The operation reliability of the turbine can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a system configuration diagram of a simulation device according to an embodiment.

FIG. 3 is a calculation flowchart of the turbine simulation device.

FIG. 4 is a flowchart of a shaft vibration calculation.

FIG. 5 is a flowchart of a hot alignment calculation.

FIG. 6 is a diagram showing activation curve data.

FIG. 7 is a heat stability calculation flowchart.

FIG. 8 is a flowchart for calculating a single residual unbalance .

FIG. 9 is a flowchart of forced imbalance calculation.

FIG. 10 is a flowchart of a miscoupling calculation.

FIG. 11 is a flowchart for calculating total unbalanced data.

FIG. 12 is a flowchart for calculating a bearing metal temperature.

FIG. 13 is a flowchart of a thrust metal temperature calculation.

FIG. 14 is a flowchart for calculating a stability limit.

FIG. 15 is a flowchart for calculating elongation / difference in elongation and a gap in a radial direction.

FIG. 16 is a flowchart for calculating elongation / difference in elongation and a gap in a radial direction.

FIG. 17 is a diagram showing a relationship between a heat transfer coefficient and time and a panula variable.

FIG. 18 is an explanatory diagram of a method for erasing time.

FIG. 19 is a diagram showing an example of a menu screen.

FIG. 20 is a diagram showing an example of a menu screen.

FIG. 21 is a diagram illustrating an example of a menu screen.

FIG. 22 is a diagram showing an example of a menu screen.

[Explanation of symbols]

 1 storage means 2 operation means

Continued on the front page (72) Inventor Takao Yamamoto 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (72) Inventor Kazuhiko Shimoda 1-1-1, Tanabe-shinda, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji (56) References JP-A-62-298605 (JP, A) JP-A-62-240402 (JP, A) JP-A-1-134703 (JP, U) (58) Fields studied (Int .Cl. ⁶ , DB name) F01D 17/24 F01D 19/00

Claims (3)

(57) [Claims] 1. An indispensable method for simulating turbine shaft vibration.
Design data storage for storing important turbine design data
Stages and turbine speed from start-up to steady-state operation
Starting curve data storage means for storing starting curve data indicating a temporal change in the temperature inside the turbine, and data indicating deformation of the rotor due to previously measured heat, and
At any point on the start curve from the start curve data
The unbalance data due to the thermal deformation of the rotor
Calculation means , pre-measured residual unbalance data and assembly of the rotor
Misalignment during assembling, indicating a deviation of the shaft center of the bearing part at the time
The difference data and the heat change of the rotor calculated by the calculation means.
Determined from start-up based on unbalanced data by shape
A prediction unit for predicting shaft vibration of the rotor until normal operation . 2. The turbine simulation apparatus according to claim 1, further comprising display means for displaying shaft vibration data obtained by said prediction means together with a limit value. 3. The method according to claim 1, wherein the calculating means is configured to determine whether the starting curve data is
Starting car based on the temperature inside the turbine obtained
Due to thermal deformation of the rotor bearing at any point on the
Error data and the error
The unbalance data due to thermal deformation of the data is calculated, and the predicting means calculates the assembly alignment measured in advance.
Error data and residual unbalanced data,
Alignment by thermal deformation of bearing part calculated by step
Error data and rotor rotor deformation caused by thermal deformation of the rotor.
From start-up to steady operation based on unbalanced data.
3. The turbine simulation device according to claim 1 , wherein the simulation of the shaft vibration of the rotor is performed .