JPH0586807A - Simulation device for turbine - Google Patents

Abstract

PURPOSE:To vary a starting condition so as to simulate an operating condition of a turbine by determining steam temperatures and heat transmitting ratios in a non-constant state and constant state of portions of the turbine on the basis of starting curve data. and providing a calculator for calculating variation of the data due to thermal expansion. CONSTITUTION:A memory 1 stores therein starting curve data indicative of operating conditions from start operation of a turbine until normal operation such as data indicating secular changes of an engine speed, an output and a steam temperature. A calculator 2 consists of, for example, a limited element program, to calculate a non-constant temperature distribution in portions of the turbine such as a high pressure rotor, an intermediate pressure rotor and a high pressure outside casing so as to calculate extension due to thermal expansion on the basis of the temperatures, the shapes of a turbine rotor and casing, and each heat transmitting ratio of the portions of the turbine, and further, to determine a radial clearance or axial clearance between a rotary portion and fixed portion of the turbine at each time on the starting curve.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art When designing a rotor, casing, etc. of a steam turbine, a constant radial gap and an axial direction are provided between a rotating part (rotor) and a stationary part (casing) of the turbine under various operating conditions. It is necessary to secure a gap.

Conventionally, there has been a finite element program for calculating the displacement of each part of a steam turbine due to thermal expansion, etc., but this finite element program can only calculate the displacement under a specific condition, and the steam like at the time of start-up. Temperature, steam pressure,
It was not possible to calculate the displacement of each part of the turbine in an unsteady state in which the rotational speed changes with time, and to calculate the radial clearance or the axial clearance between the rotor and the casing. Therefore, conventionally, a mechanical running test was conducted by actually passing steam through a steam turbine to confirm whether or not the rotating part and the stationary part were in contact with each other.

[0004]

However, the mechanical running test described above cannot be tested under the same conditions as the actual operating conditions due to the constraints of the test equipment. Therefore, for safety reasons, there is a certain margin in the design value. However, the maximum turbine efficiency was not always obtained.

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

An object of the present invention is to provide a simulation apparatus capable of simulating the operating state of a turbine by changing various starting conditions.

[0007]

FIG. 1 illustrates the principle of the present invention. In the figure, the storage means 1 stores start-up curve data showing operating conditions from the turbine start-up to the steady-state operation, for example, data showing a temporal change in the number of revolutions, output, and steam temperature.

The computing means 2 is composed of, for example, a finite element program and the like, and each part of the turbine (for example, a high pressure rotor,
Unsteady temperature distribution of medium pressure rotor, high pressure outer casing, etc.) is calculated, and elongation due to thermal expansion is calculated from those temperatures and fixed data such as turbine rotor, casing shape, and heat transfer coefficient of each part of turbine. Further, by combining the calculated elongation amounts of the respective turbine parts, the elongation of the respective turbine parts at each time on the above-mentioned start curve, the difference in elongation, etc. are calculated, and the radial gap between the rotating part and the fixed part of the turbine,
Alternatively, the axial clearance is obtained.

[0009]

According to the simulation apparatus of the present invention, the radial clearance and the axial clearance between the rotating part and the stationary part of the turbine from the start-up of the turbine to the steady operation are set under actual operating conditions without operating the turbine. Since it can be confirmed under the same conditions as above, the mechanical running test is not necessary and the test cost and test time can be reduced.

Further, by changing the start curve data, it is possible to confirm the radial clearance and the axial clearance between the rotating part and the fixed part of the turbine under various starting conditions, so that the operation reliability of the turbine can be improved. The sex can be enhanced.

[0011]

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

In FIG. 1, a mouse 11 and a Japanese keyboard 12 are used to input commands such as selection of simulation items, storage of data, and output of results to an output device. The disk 13 and the magnetic tape device 14 store design data, various calculation programs to be 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 the simulation result. The CPU 18 executes various calculation programs to simulate a steam turbine and controls the operation of each of the above devices.

Next, FIG. 3 is a diagram showing an overall flow chart of a calculation program executed by the simulation apparatus. The simulation programs are roughly divided into shaft vibration response calculation program, stability limit calculation program, bearing metal temperature calculation program, elongation / elongation difference,
Radial clearance calculation program, life calculation program 5
It can be divided into two.

First, the shaft vibration calculation program will be described. The overall flow chart 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 the unit, etc., assembling alignment and bearing load due to hot alignment. is doing.

First, a hot alignment calculation program for obtaining hot alignment data that affects 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, or the concrete support pillars that support the bearing base to thermally expand and bearing. That is, the height of the portion is displaced, and the axial center of the rotor is displaced. When the bearing height is displaced, the bearing load becomes non-uniform, causing shaft vibration.

In step S1 of FIG. 5, it is determined whether or not hot alignment is taken into consideration. If hot alignment is to be taken into consideration, turbine start mode data is read in step S2. Here, the start-up mode data indicates a state at the time of starting the operation of the turbine. It is a cold start in which the turbine is stopped for a long time and then started, or a worm in which the turbine is stopped and then started for a certain time (for example, on weekends) It is data indicating whether the turbine was started under the conditions of start or hot start in which night operation is stopped and started every day.

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 start-up curve data represents a pattern of continuous changes with time of the turbine rotation speed, output, main steam temperature, reheat steam temperature, etc. at the time of start-up, as shown in FIG.

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

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

After the start curve data for a predetermined number of data has been read, a hot alignment data file X (I, J) is created from these data in step S6. It should be noted that if the condition is set such that the hot alignment is not taken into consideration when setting the simulation condition, the determination in step S1 becomes NO and the hot alignment data X (I, J) becomes "0" in step S7. As a result, the effect of hot alignment can be removed and the axial vibration due to other elements can be simulated.

Another factor that affects the bearing load is alignment during assembly. This is not always the case when the turbine is actually assembled to the bearing height as designed, and a certain degree of misalignment of the rotor shaft center occurs due to an assembly error. Therefore, a certain alignment error that is considered to occur at the time of assembly is given to simulate whether or not dangerous vibration occurs in the turbine rotor due to the alignment error.

The assembling alignment calculation program, which is not particularly shown, is a process for creating an assembling alignment data file consisting of 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 assembly 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 which affects the unbalance amount of the rotor will be described with reference to the flowchart of FIG.

Due to the metallurgical structure of the turbine rotor or the non-uniformity of the heat treatment, the rotor may bend in a certain direction under high temperature conditions, which may cause an imbalance and the vibration of the rotor may change during operation. .. The heat stability is the one in which the bending of the rotor determined by the steam temperature is replaced with an equivalent unbalance amount on the rotor by using the axial bending data obtained during the heat treatment.

In step S8 of FIG. 7, it is determined whether heat stability is taken into consideration. When considering the heat stability, 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 6 and the number of ambranus conversion surfaces is 3, three amplitude data A and phase angle data θ are obtained for each rotor. 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 the six rotors.

In the next step S10, the turbine start mode is set.
Read the data, and in step S11, start the car.
Read the steam temperature data etc. at each sampling point.
In step S12, three amplitudes for each of the six rotors
A, the phase angle θ data, the amplitude and
Inverse matrix α of influence coefficient α that connects with weight α ^-1Squared
Weight unbalanced day due to heat stability
Calculate W (I, J).

Then, in step S13, a file of heat stability weight data W (I, J) is created. If the heat stability is not taken into consideration when setting the simulation conditions, the determination in step S8 becomes NO and step S14
Then, the heat stability weight data X (I, J) becomes "0", and the influence of heat stability is removed.
It is possible to simulate the shaft vibration due to other factors.

Next, FIG. 8 is a program for converting the single residual imbalance data into the weight imbalance 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 will not be zero, so vibration may increase when the turbines are assembled by combining the rotors depending on the position of the residual unbalance.

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 vibration due to the residual unbalance of the rotor can be calculated.

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

When setting the simulation condition, if the condition that the single residual imbalance is not taken into consideration is set, 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 imbalance of the single substance.

Next, the forced imbalance calculation program will be described with reference to the flowchart of FIG. During turbine operation, the turbine blade is cut off and the vibration changes rapidly, and contact occurs between the rotating body and the stationary portion in places where the clearance between the rotating body and the stationary portion is small, such as in steam seals, causing friction. The shaft may bend due to heat and the vibration state may change. Therefore, in this forced unbalance calculation program, an unbalance amount is forcibly added to a specific portion of the rotor, and it is simulated whether or not a significant vibration change occurs in the turbine due to the unbalance amount.

In step S21 of FIG. 9, it is determined whether or not the forced imbalance is taken into consideration. When the forced imbalance is taken into consideration, the weight and phase angle data of a specific paragraph are read from the forced imbalance data file in step S22.
Here, since the weight and phase angle data of each paragraph when the rotor is divided into a large number of paragraphs are stored in the forced unbalanced data file, in step S22, the weight and phase angle data of these many paragraphs are stored. From among the above, the weight and phase data on the three unbalance conversion surfaces obtained by the heat stability data calculation program, the single residual unbalance data calculation program, etc. 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 the three unbalance conversion surfaces of each rotor.

When setting the simulation condition, if the condition that the forced imbalance data is not taken into consideration is set, the determination in step 21 becomes NO, and the process proceeds to step 24, where the weight amount data WI (I, J), “0” is set in the phase angle data θI (I, J). As a result, it is possible to remove the influence of the forced imbalance data and perform the simulation.

Next, the miscoupling calculation program will be described with reference to the flow charts of FIGS. 10 (a) and 10 (b). Although the rotors are connected by a coupling, a center runout, a surface runout of the coupling due to a variation in processing of the coupling itself, or a center runout or a surface runout due to an error in assembling the coupling. Therefore, in this miscoupling calculation program, those center runout amounts and surface runout amounts are converted into equivalent unbalance amounts.

In step S25 of FIG. 10A, the center runout amount and the face runout amount 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 amount and the face runout amount are read from the above data file.
In the next step S28, the axial deflection amount calculation subroutine program is executed to convert the center runout amount and the surface runout amount into the axial deflection amount data, and further the unbalance amount calculation subroutine program is executed to calculate the axial deflection amount unbalance amount data. Convert to. Then, an unbalance amount data file due to miscoupling is created based on the calculated unbalance amount data.

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

First, in step S31 of FIG. 11, the heat stability calculation program of FIG. 7 is executed to read the amplitude and phase angle data due to 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, the weight and phase angle data are read from the forced imbalance data file created by the forced imbalance calculation program of 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 of 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 of 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, the weight data is added to obtain unbalanced data on the unbalance conversion surface of each rotor. In step S40, the total imbalance data files SUMS, SUPS are calculated from the above addition results.
To create.

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

Although the shaft vibration response program is not shown in particular, it is a modification of a part of the existing shaft vibration calculation program and is different from the conventional shaft vibration calculation program.
Bearing load and unbalance amount due to hot alignment, heat stability, etc. are calculated based on start curve data where steam temperature, rotation speed, output, etc. change with time, and shaft vibration in unsteady state is simulated from these data. The point is that it is possible.

Next, a program for calculating the bearing metal temperature that supports 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 during assembly is an influence coefficient that indicates how much the displacement of the bearing height during assembly affects the load. Then, in the next step S42, the calculation result of the bearing load due to the assembling alignment of each bearing is output.

In step S43, from the start curve data by the start curve reading program and the data for instructing at what interval the calculation is performed, N points, that is, at over speed, no load rating, 50% load, and rated load Read the time and panula variables at arrival, at rating, at points of inflection and at intervals of minutes. Here, the panura variable is a value represented by the panura variable = rotation speed at time t / rated rotation speed + load at time t / rated load, from which position the current operating state is on the starting curve. I know if there is.

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

Then, in step S46, it is determined whether or not the calculation of the bearing load has been 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. The fixed data for hot alignment calculation is an influence coefficient indicating how the bearing height displacement due to hot alignment affects the bearing load.

Next, in step S48, the change in bearing load due to hot alignment is obtained using the hot alignment calculation program shown in FIG. Then step S
At 49, the bearing load by the assembling alignment obtained at step S42 and the bearing load by the hot alignment are added to calculate the entire bearing load.

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
Displays the metal temperature of each bearing obtained by calculation in.

By these processes, it is possible to confirm whether or not the metal temperature of each bearing at each point on the starting curve is below the limit value. Further, at this time, by changing the start curve data, it is possible to confirm whether the bearing metal temperature falls within the limit value under various start 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, the Panula variable at an arbitrary time t is obtained from the starting curve data. Step S
At point 53 on the start curve by the start curve reading program at 53, that is, at overspeed, at no load rating, at 50% load, at rated load, at rating,
Read the time and panula variables at each point of inflection and minutes apart.

In the next step S54, 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 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 consisting of 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 fixed data for thrust bearing load calculation 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.

By these processes, the thrust metal temperature at each point on the starting curve can be confirmed, and further, it can be confirmed whether or not the temperature is within the limit value. Next, the stability limit calculation program will be described with reference to the flowchart of FIG. Here, the stability limit is the limit rotational speed at which the turbine can be stably driven when the rotational speed of the turbine is increased, and if the rotational speed is further increased, vibrations may diverge and become unstable. Refers to the state.

In step S61 of the stability limit calculation program of FIG. 14, the bearing load is calculated from the assembly alignment data and the assembly alignment calculation fixed data using the assembly alignment calculation program. In the next step S62, the total bearing load due to the alignment during assembly is output.

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

Further, in step S66, at the time of no load rating,
When the rated load is reached, it is determined whether or not the calculation of the bearing load for each time at the rated time has been completed. If the calculation of 3 points is not completed, the fixed data for 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 amount of change in bearing load due to hot alignment is calculated by the hot alignment calculation program shown in FIG.

Further, in step S69, the bearing loads due to the assembling alignment and the hot alignment are added to obtain the total bearing load. Then, in step S70, the rotational speed at which the bearing can be stably rotated by applying a load of a certain amount or more is calculated from the bearing load and the fixed data for stability limit calculation.

After that, the rotational speed at the stability limit calculated by step S71 is displayed on the display. By these processes, it is possible to confirm the stability limit at each point on the starting curve, and also it is possible to confirm whether the rotational speed at each point has a margin with respect to the stability limit.

Next, a program for calculating the expansion / expansion difference between the rotor and the casing and the radial clearance will be described with reference to FIGS.
This will be described with reference to the flowchart in FIG. 15 and 1
6 is one program divided and expressed,
15 of FIG. 15 leads to of FIG.

The shaft center movement amount calculation result of FIG. 15 is the calculation result of the shaft center movement amount by an unillustrated shaft center movement amount calculation program. This is the amount of lifting of the turbine rotor due to the change of the oil film thickness of the bearing portion. Is calculated. The shaft center movement amount calculation result, the shaft vibration calculation result by the shaft vibration calculation program described above, the main stage correspondence table indicating the calculation place in these programs, and the reference distance are shown in FIG. Output to the vibration addition program.

The rotor blade expansion coefficient, rotor blade length and average expansion coefficient shown in FIG. 15 and the rotational speed and load data shown in FIG. 16 are the FETE program for the rotor shown in FIG. 16 (a finite element for calculating the displacement of each part of the rotor). Have entered in the program), F
Inside the ETE, the expansion of the blade due to thermal expansion and the elongation of the blade due to centrifugal force during rotation are calculated.

In the initial metal temperature calculation program of FIG. 15, the start-up mode data indicating whether the start-up state is cold start, warm start, or hot start, the elapsed time after the operation is stopped, and the start-up. Post-disconnection time and 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 in FIG.

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

The partial load calculation program is a program for calculating the steam temperature and pressure for each hour at a specific location, and the calculation result is output to the post-processing program.
In the post-processing program, the steam temperature and pressure at each stage of the rotor and casing are calculated from the steam temperature and pressure at the specific stage (location) obtained by the partial load calculation program, and the stage correspondence table. Output to the condition creation program.
By these processes, the steam temperature and the pressure at arbitrary positions of the rotor and the casing are obtained every hour.

Next, in order to obtain the heat transfer coefficient of each portion of the rotor and the casing, linear interpolation is performed from the relationship between the panula variable with respect to time and the relationship between the panura variable and the heat transfer coefficient as shown in FIG. Calculate the heat transfer coefficient of. Here, the reason why the heat transfer coefficient is calculated by the Panula variable is that the heat transfer coefficient is affected by the flow velocity of steam flowing into the turbine, etc. Is.

Then, the correspondence table of the heat transfer coefficient of each stage for each time is output to the boundary condition preparation program. Here, the step means that the rotor and the casing are divided into a plurality of finite elements in the FETE program, and are cut in a radial direction 1
It refers to one block, and one step is composed of a plurality of elements at the same node position. By these processes, the heat transfer coefficient of any stage of the rotor and the casing can be obtained.

The boundary condition creation program is for the steam temperature and pressure for each stage of the rotor and casing obtained by the above-mentioned post-processing program, and the heat transfer coefficient of each stage for each stage obtained from the Panula variable. A conversion table is a program for converting the correspondence table and the input format of the FETE program, and 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 the turbine parts are displaced when pressure is applied, and the correspondence table is output to the casing FETE program.

By the way, the steam flowing into the turbine is cooled by driving a load, and part of it becomes water and accumulates in the lower portion of the casing. As a result, a temperature difference occurs between the upper part and the lower part of the casing, the temperature difference causes the casing to warp, and the radial gap with the rotor becomes uneven.
Therefore, the upper and lower temperature difference data and the upper and lower temperature difference calculation shape data are output to the casing FETE program (a finite element program that calculates the displacement of the casing), and the FE
The upper / lower temperature difference calculation program inside the TE calculates the displacement of the casing due to the upper / lower temperature difference.

Next, in order to calculate the displacement of the stationary blade due to thermal expansion, 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 steam temperature of each portion of the rotor and casing of the calculation control file at each time,
The displacement due to the thermal expansion and the displacement due to the centrifugal force of each part of the finite element of the rotor and the casing are calculated based on the pressure and the heat transfer coefficient.

The calculation of the radial clearance and the axial clearance between the rotor and the casing is basically performed by the same program, but the axial center movement amount and the shaft vibration calculation result, the vertical temperature difference of the turbine casing, and the static Since the blade elongation or the like has little effect on the axial clearance, the axial displacement is not calculated in those calculation programs.

The shaft center movement amount / axis vibration addition program uses the rotor center FETE to calculate the shaft center movement amount calculation result and the shaft vibration calculation result.
This is a program for calculating the displacement in the radial direction of the rotor in consideration of the axial movement amount and the axial vibration in addition to the rotor displacement obtained by the program.

By the way, in the case of adding the axial center movement amount calculation result and the shaft vibration calculation result by the above program to the calculation result of the FETE program, the axial center movement amount calculation program,
Since the calculation time and the calculation place of each program of the axial vibration calculation program and the above-mentioned elongation / elongation and radial clearance calculation program do not match, in order to obtain the radial clearance considering all of these influences, It is necessary to match the calculation time and calculation place of the program.

Therefore, in the present embodiment, the calculation time and the calculation place of each program described above are matched to each other so that the displacement at any place and time can be calculated. FIG. 18 is an explanatory diagram of a method within time. An example will be described below 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 / expansion difference and radial clearance calculation program.

Time t of bearing metal temperature calculation program
The calculation results of the bearing metal temperatures at _m-1 , t _m , and t _{m + 1} are V _m-1 , V _m , and V _{m + 1} (see FIG. 18). First,
It is examined where the calculation time T _{n of the} elongation / expansion difference / radial clearance calculation program corresponds to the calculation time of the bearing metal temperature calculation program. Then, if there is a time of t _m <T _n <t _{m + 1} , the bearing metal temperature at the time T _n is the calculated value V of the bearing metal temperature at the time t _m and the time t _{m + 1.}
It can be calculated from _m and V _{m + 1} by the following equation.

V _n = (V _{m + 1} −V _m ) × (T _n −t _m ) / (t _{m + 1} −t _m ) −V _{m From} this calculation formula, at time T _{n as} shown in FIG. The bearing metal temperature V _n can be obtained.

By repeating these calculations for each time T _i of the elongation / elongation difference / radial clearance calculation program, the calculation times of the two programs can be matched. If distance data is used instead of time in the above formula, the calculation locations of the two programs can be matched.

In this way, if the calculation times and locations of the bearing metal temperature calculation program, the shaft vibration calculation program, the elongation / expansion difference, and the radial clearance calculation programs are matched, the displacements obtained by the respective programs are calculated. Then, the axial extension and the radial extension of the rotor and the casing are calculated.

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

Further, the predicted values of the radial clearance and the axial clearance inside the turbine are obtained from the dimensions of each part that can be measured in the process of actually assembling the turbine. Since these values show the actual axial clearance and radial clearance of the turbine before starting, these values and the above-mentioned elongation and elongation,
The final axial clearance and radial clearance are calculated from the calculation results obtained by the radial clearance calculation program and displayed on the screen.

Further, the time, volume average temperature, surface temperature, etc. 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 formula.

Ε = β × (surface temperature-volume average temperature) × k
(1 / (1-ν)) Then, the allowable number of repetitions N is obtained from the strain ε from the low cycle fatigue curve, and the life consumption amount 1 / N due to the strain ε generated by operating the turbine this time is obtained. Cumulatively determine the lifespan consumption of the turbine.By using this lifespan consumption program, it is possible to know how much the turbine life has been consumed by operating the turbine. Note that the expansion coefficient β, strain concentration coefficient k, etc. It is given as fixed data for consumption calculation.

Next, FIGS. 19 to 22 are views showing an example of a menu screen displayed on the display in the simulation device of the example. First, as shown in FIG. 19, as the initial menu, "database creation", "simulation item selection", "database registration",
Each item "End" is displayed.

First, "create database" is selected and the conditions and calculation results already set are read out on the database. Next, select the simulation item and call the item selection of the sub menu. In this state, if shaft vibration is selected as a simulation item, as shown in FIG. 20, "change data", "display screen", "print out", and "return to previous screen" are displayed. It

If "change data" is selected, "start curve" to "hot alignment during assembly" will be selected.
Since the items related to the shaft vibration calculation program up to are displayed, the 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 turbine simulation 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 / elongation difference" is selected as a simulation item. , FIG. 22
As shown in, each item related to “growth / growth difference” is displayed.

In the menu screen of FIG. 22, when "Screen display" is selected, a submenu of screen display is called up, and "Time-extension / expansion difference curve", "Time-radial gap change curve", "Radial gap" are displayed. Since items such as "display of entire change" are displayed, by selecting these items, it is possible to display the temporal change of the radial clearance or the overall change of the radial clearance of the turbine and the rotor on the display.

When the simulation is completed,
By selecting "register database" 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 each item displayed on the menu screen, the simulation conditions are arbitrarily set and the axial vibration calculation, the radial clearance calculation and the like are executed, and the result is set to the limit value or 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, the shaft vibration at any place of the steam turbine at any time, the bearing metal temperature, the stability limit, the expansion / elongation difference, the radial clearance,
Since it is possible to calculate the axial clearance, etc., it is possible to simulate the operating state of the turbine not only in the steady state but also in the unsteady state, and confirm the operating reliability of the turbine under the same conditions as the actual operating conditions. You can This eliminates the need for a mechanical running test, thus reducing test cost and test time.

Further, in the above simulation device,
Since the simulation conditions can be set arbitrarily, it is also possible to simulate the operating state of the turbine under conditions that are stricter than the actual operating conditions and check how much the turbine actual value has a margin with respect to the rated value.

[0097]

According to the present invention, since the radial clearance and the axial clearance of each portion of the turbine at each time on the starting curve can be obtained, the required radial clearance and the axial clearance can be secured, In addition, it is possible to design so that the turbine efficiency is maximized. Further, since the same state as the actual operating state can be simulated, the mechanical running test is unnecessary and the test cost and test time can be reduced. Furthermore, the radial clearance and axial clearance of each part of the turbine under more severe operating conditions, which cannot be confirmed by the mechanical running test, can be checked, so that the operational reliability of the turbine can be further improved.

[Brief description of 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 a turbine simulation device.

FIG. 4 is a flowchart of shaft vibration calculation.

FIG. 5 is a hot alignment calculation flowchart.

FIG. 6 is a diagram showing start-up curve data.

FIG. 7 is a heat stability calculation flowchart.

FIG. 8 is a flowchart of a simple residual Amberanne calculation.

FIG. 9 is a forced imbalance calculation flowchart.

FIG. 10 is a miscoupling calculation flowchart.

FIG. 11 is a total imbalance data calculation flowchart.

FIG. 12 is a bearing metal temperature calculation flowchart.

FIG. 13 is a thrust metal temperature calculation flowchart.

FIG. 14 is a stability limit calculation flowchart.

FIG. 15 is a flowchart of elongation / expansion difference and radial clearance calculation.

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

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 within 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 showing 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 computing means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location F01K 13/02 B 8503-3G (72) Inventor Ikuro Kishi 1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 within Fuji Electric Co., Ltd. (72) Inventor Haruho Nishimoto 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Fuji Electric Co., Ltd.

Claims (5)

[Claims] 1. A storage means (1) for storing start-up curve data indicating operating conditions from a turbine start-up to a steady operation.
And a calculation means (2) for calculating the radial clearance between the rotating part and the fixed part of the turbine at any location and at any time of the turbine based on the starting curve data stored in this storage means (1) And a turbine simulation device. 2. The calculating means (2) at least radially expands a rotating part and a stationary part due to thermal expansion, a rotating part radially expands due to centrifugal force during rotation, and a radial gap due to a vertical temperature difference of the casing. The radial gap between the rotating portion and the stationary portion of the turbine at any location and at any time of the turbine is calculated by calculating one of the radial expansion of the casing due to the change and the pressure. Turbine simulation device. 3. Storage means (1) for storing start-up curve data showing operating conditions from turbine startup to steady operation
And a calculation means (2) for calculating the radial clearance between the rotating part and the fixed part of the turbine at any location and at any time of the turbine based on the starting curve data stored in this storage means (1) And a display means for displaying the radial gap between the rotating portion and the fixed portion obtained by the calculating means (2) together with a predetermined limit value. 4. A storage means (1) for storing start-up curve data indicating an operation condition from a turbine start-up to a steady operation.
And a calculation means for calculating the axial clearance between the rotating part and the fixed part of the turbine at an arbitrary location of the turbine and at an arbitrary time based on the starting curve data stored in the storage means (1). A turbine simulation device characterized by the above. 5. A storage means (1) for storing start-up curve data indicating operating conditions from a turbine start-up to a steady operation.
And a calculating means for calculating the axial clearance between the rotating part and the fixed part of the turbine at an arbitrary location of the turbine at an arbitrary time based on the starting curve data stored in the storage means (1), A turbine simulation device, comprising: a display unit that displays the axial gap between the rotating unit and the fixed unit, which is calculated by the calculating unit, together with a predetermined limit value.