Multi-source excitation steam turbine generator set vibration transmission path analysis method

Abstract

The invention discloses a multi-source excitation steam turbine generator set vibration transmission path analysis method. A steam turbine generator set vibration source and the type of a transmission path corresponding to the vibration source are divided; determining M alternative vibration source measuring points near each vibration source of the steam turbine generator set, and randomly selecting m optional vibration source measuring points from M; establishing a working condition transmission path analysis equation from m optional vibration source measuring points of the steam turbine generator unit to n target response measuring points on a unit supporting platform; on the basis of a working condition transmission path analysis equation, m optimal vibration source measuring points are preferably selected from the alternative vibration source measuring points M through a multi-target intelligent optimization algorithm; vibration response signals of m preferable vibration source measuring points and n target response measuring points are synchronously collected through a vibration sensor, and a transfer function matrix is solved. The key vibration source path transmission rule of the steam turbine generator set can be completely reflected, and the method has universality.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration source identification and control of power equipment, and in particular relates to a vibration transmission path analysis method for a steam turbine generator set with multi-source excitation. Background Art

[0002] Steam turbine generator sets generate the primary power and electricity for nuclear-powered ships, directly impacting their navigational economy, safety, maneuverability, and stealth performance. Marine high-speed, direct-coupled steam turbine generator sets are subject to frequent operating conditions, multiple and highly coupled vibration sources, and noise contamination of measured vibration signals. A series of operating transfer path analysis methods can analyze the vibration transfer path from a vibration source to a target point using only the responses of the source measurement points and the target point. However, in steam turbine generator application, these methods face challenges such as erroneous identification of the true vibration source due to cross-coupling of multiple types of vibration sources, ill-posed matrix inversion due to signal crosstalk, and omission of the number and location of vibration sources. Therefore, it is imperative to consider the characteristics and distribution of vibration sources in steam turbine generator sets and innovate transfer path analysis methods by combining intelligent optimization of vibration source measurement points and locations, unified representation of different types of vibration sources, and well-conditioned vibration source matrix construction to accurately identify and locate vibration sources in steam turbine generator sets under complex conditions. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention provides a vibration transmission path analysis method for a steam turbine generator set with multi-source excitation that can accurately identify and locate the vibration.

[0004] To achieve the above objectives, the present invention provides a method for analyzing vibration transfer paths of a steam turbine generator set with multi-source excitation. The specific process is as follows: 1) According to the structure and distribution characteristics of the steam turbine generator set, the types of vibration sources and corresponding transmission paths of the vibration sources are classified; 2) Determine the vibration sources near the steam turbine generator set M Alternative vibration source measurement points, as well as the preliminary location and type of each alternative vibration source measurement point, and from M Any selection m optional vibration source measurement points, and M ≥(2~3)× m ; 3) Build a steam turbine generator set m A selected vibration source measuring point to the unit support platform n The working condition transfer path analysis equation between the target response measurement points; 4) Based on the working condition transfer path analysis equation, at the alternative vibration source measurement point M Through multi-objective intelligent optimization algorithm to select mOptimal vibration source measuring points and the position of each optimal vibration source measuring point; 5) Run the steam turbine generator set under different working conditions (different speeds or different loads) and collect the vibration data synchronously through the vibration sensor. m Optimal vibration source measurement points and n The vibration response signal of each target response measurement point is obtained, and then the transfer function matrix is ​​solved using the working condition transfer path analysis equation.

[0005] Furthermore, by multiplying the transfer function matrix by the vibration source measurement point input under any working condition, response prediction, contribution analysis, and identification of the vibration source and the vibration source transmission path from the vibration source measurement point to the target response measurement point can be achieved.

[0006] Furthermore, the types in step 1) include: ① steam supply pipe vibration excitation → steam inlet pipe → cylinder → unit support platform; ② exhaust pipe vibration excitation → exhaust pipe → cylinder → unit support platform; ③ rotor system → excitation of front and rear bearings of steam turbine → bearing seat → unit support platform; ④ rotor system → excitation of front and rear bearings of generator → bearing seat → unit support platform; ⑤ steam flow excitation in steam turbine → unit cylinder → unit support platform; ⑥ lubricating oil pipe or cooling water pipe → cylinder → unit support platform.

[0007] Furthermore, in step 2), the number of vibration source measurement points is selected m = m in + m out + m r1 + m r2 + m f + m o ; in, m in is the number of vibration source measurement points in the steam inlet pipe, m out The number of vibration source measurement points on the exhaust pipe, m r1 is the number of turbine side vibration source measurement points near the rotor system bearings, m r2 is the number of generator side vibration source measurement points near the rotor system bearings, m f is the number of vibration source measurement points on the cylinder, m o The number of vibration source measuring points on the lubricating oil pipe or cooling water pipe; The vibration source measurement points of the steam inlet pipe and the exhaust pipe are both of the vibration displacement difference ∆ X(ω), the vibration source measurement points on the turbine side near the rotor system bearings and the generator side are all of vibration acceleration type, and the vibration source measurement points on the cylinder and the lubricating oil pipe or cooling water pipe are all of vibration acceleration type.

[0008] Furthermore, in step 3), the steam turbine generator set m A selected vibration source measuring point to the unit support platform n The operating condition transfer path analysis equation between the target response measurement points is as follows: is the vibration source measurement point matrix, where the elements X ki Indicates the k In the working condition, a The vibration response value of the optimal vibration source measurement point, a =1,2,……, m ; k =1,2,……, r ;when a =1,2,……, m in + m out hour, X ka The value is the difference in vibration displacement ∆ X (ω), the remaining columns X ka The value is the vibration acceleration; is the transfer function matrix, where the elements are T aj Indicates the a The first preferred vibration source measuring point to the j The transfer function between target response measurement points; is the response value matrix of the target response measurement point, where the elements P kj Indicates the k In the working condition, j The response value of each target response measurement point; r is the number of working conditions, and r Greater than m .

[0009] Furthermore, in step 4), based on the working condition transfer path analysis equation, at the alternative vibration source measurement point M Through multi-objective intelligent optimization algorithm to select m The specific process of selecting the optimal vibration source measuring point and the location of each optimal vibration source measuring point is as follows: 41) Normalize the response values ​​of the vibration source measurement points on different types of transmission paths and M Any selection from the candidate vibration source measurement points m Select a vibration source measurement point and then calculate m Optional vibration source measurement points to n The re-coherence coefficient of each target response point based on partial coherence; Where, , For the i Conditional input of vibration source measurement points and target response measurement points p The conditional cross spectrum of For the i The conditional autospectrum of each vibration source measurement point, Indicates the conditional autospectrum of the target response measurement point, conditional input Indicates the least square method from Remove arrive The linear effect of 42) Using the condition number to evaluate the ill-conditioned characteristics of the vibration source measurement point matrix: 43) Determine the two goals of optimizing the vibration source measurement points Min , } Select the optimization variable as follows: the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point; The constraints are: γ ≥ 0.8, where at least one vibration source measuring point corresponding to the first to fifth types of vibration source measuring points in step 1) is selected as the preferred vibration source measuring point.

[0010] 44) Use NSGA-II algorithm to implement iterative optimization of multi-objective intelligent optimization algorithm and determine the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point.

[0011] Furthermore, the formula for solving the transfer function matrix in step 5) is: .

[0012] Furthermore, when the hour, Does not exist, use Alternative .

[0013] Furthermore, the vibration source measurement point matrix When inverting the matrix, ill-posed problems will still occur at some frequency points. The Tikhonov regularization method is used to deal with the ill-posed problem when inverting the ill-conditioned matrix.

[0014] Furthermore, in step 43), at least one vibration source measuring point corresponding to the sixth type of vibration source measuring point in step 1) is selected as a preferred vibration source measuring point or is not selected.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the vibration transfer path analysis method of a steam turbine generator set with multi-source excitation of the present invention fully exploits the characteristics of the structure of the steam turbine generator set and its vibration source distribution, and selects different types of vibration signals to represent different types of vibration sources to reduce the coupling influence between multiple excitation sources. Thus, an analysis model of the multi-excitation vibration source of the unit and its key transfer path is established, which can more completely reflect the key vibration source path transfer law of the steam turbine generator set and has universality. With the biased stem-based heavy correlation coefficient and condition number as the target, the optimal vibration source measurement point and position are selected through a multi-objective intelligent optimization algorithm, which can not only avoid the problem of vibration source omission inducing vibration source identification errors, but also reduce the matrix inversion distortion caused by cross-coupling between vibration sources. In combination with the preferred vibration source measurement point and the target response measurement point, the embedded regularization method proposes a more stable working condition transfer path analysis method, which can be used to realize the identification and accurate positioning of the main excitation source and corresponding transfer path of the vibration response system of the steam turbine generator set under complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : A graph of the coherence coefficient from the source measurement point to the target response measurement point in the embodiment; Figure 2 Matrix condition number distribution diagram in the embodiment; Figure 3 : This is a contribution spectrum diagram of each path to the target response measurement point in the embodiment, where different colors represent the normalized decibel values ​​of the vibration response of different target response measurement points. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation is as follows: 1) According to the structure and distribution characteristics of the steam turbine generator set, the types of vibration sources and corresponding transmission paths of the vibration sources are classified; Among them, the types include: ① Steam supply pipe vibration excitation → steam inlet pipe → cylinder → unit support platform; ② Exhaust pipe vibration excitation → exhaust pipe → cylinder → unit support platform; ③ Rotor system → excitation of front and rear bearings of steam turbine → bearing seat → unit support platform; ④ Rotor system → excitation of front and rear bearings of generator → bearing seat → unit support platform; ⑤ Steam flow excitation in steam turbine → unit cylinder → unit support platform; ⑥ Lubricating oil pipe or cooling water pipe → cylinder → unit support platform.

[0019] 2) Determine the vibration sources near the steam turbine generator set M Alternative vibration source measurement points, as well as the preliminary location and type of each alternative vibration source measurement point, and from M Any selection m optional vibration source measurement points, and M ≥(2~3)× m ; m = m in + m out + m r1 + m r2 + m f + m o ; in, m in is the number of vibration source measurement points in the steam inlet pipe, m out The number of vibration source measurement points on the exhaust pipe, m r1 is the number of turbine side vibration source measurement points near the rotor system bearings, m r2 is the number of generator side vibration source measurement points near the rotor system bearings, m f is the number of vibration source measurement points on the cylinder, m o The number of vibration source measuring points on the lubricating oil pipe or cooling water pipe; The vibration source measurement points of the steam inlet pipe and the exhaust pipe are both of the vibration displacement difference ∆ X (ω), the vibration source measurement points on the turbine side near the rotor system bearings and the generator side are all of vibration acceleration type, and the vibration source measurement points on the cylinder and the lubricating oil pipe or cooling water pipe are all of vibration acceleration type.

[0020] 3) Build a steam turbine generator set m A selected vibration source measuring point to the unit support platform nThe working condition transfer path analysis equation between the target response measurement points; The working condition transfer path analysis equation is as follows: is the vibration source measurement point matrix, where the elements X ki Indicates the k In the working condition, a The vibration response value of the optimal vibration source measurement point, a =1,2,……, m ; k =1,2,……, r ;when a =1,2,……, m in + m out hour, X ka The value is the difference in vibration displacement ∆ X (ω), the remaining columns X ka The value is the vibration acceleration; is the transfer function matrix, where the elements are T aj Indicates the a The first preferred vibration source measuring point to the j The transfer function between target response measurement points; is the response value matrix of the target response measurement point, where the elements P kj Indicates the k In the working condition, j The response value of each target response measurement point; r is the number of working conditions, and r Greater than m .

[0021] 4) Based on the working condition transfer path analysis equation, at the alternative vibration source measurement point M Through multi-objective intelligent optimization algorithm to select m The specific process is as follows: 41) Normalize the response values ​​of the vibration source measurement points on different types of transmission paths and M Any selection from the candidate vibration source measurement points m Select a vibration source measurement point and then calculate m Optional vibration source measurement points to n The re-coherence coefficient of each target response point based on partial coherence; Where, , For the i Conditional input of vibration source measurement points and target response measurement points p The conditional cross spectrum of For the i The conditional autospectrum of each vibration source measurement point, Indicates the conditional autospectrum of the target response measurement point, conditional input Indicates the least square method from Remove arrive The linear effect of 42) Using the condition number to evaluate the ill-conditioned characteristics of the vibration source measurement point matrix: 43) Determine the two goals of optimizing the vibration source measurement points Min , } Select the optimization variable as follows: the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point; The constraints are: γ ≥ 0.8, where at least one vibration source measuring point is selected as the preferred vibration source measuring point for the corresponding positions of the vibration source measuring points of the ① to ⑤ types in step 1), while the preferred vibration source measuring point can be selected for the ⑥ type.

[0022] 44) Use NSGA-II algorithm to implement iterative optimization of multi-objective intelligent optimization algorithm and determine the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point.

[0023] 5) Run the steam turbine generator set under different working conditions (different speeds or different loads) and collect the vibration data synchronously through the vibration sensor. m Optimal vibration source measurement points and n The vibration response signal of the target response measurement point is then used to solve the transfer function matrix using the working condition transfer path analysis equation. ; because ,so Does not exist, use Alternative .

[0024] Vibration source measurement point matrix When inverting the matrix, ill-posed problems will still occur at some frequency points. Therefore, the Tikhonov regularization method is used to deal with the ill-posed problem when inverting the ill-conditioned matrix.

[0025] 6) According to the transfer function matrix By multiplying the vibration source measurement point of any working condition input, the response prediction, contribution analysis, and identification of the vibration source and vibration source transmission path from the vibration source measurement point to the target response measurement point can be achieved.

[0026] Example The transfer path analysis method of the present invention is applied to the vibration transfer path analysis of a high-speed direct-connected steam turbine generator set. First, the type of the main transfer path to be analyzed is determined in combination with the structural characteristics and operating rules of the unit; then, a preliminary test is performed on the vibration conditions of the vibration source measuring points, and the positions of the alternative vibration source measuring points are preliminarily determined. Then, any optional vibration source measuring points are randomly selected from the alternative vibration source measuring points, and the number of vibration sources selected for each type of transfer path is: 3 for No. ①; 3 for No. ②; 3 for No. ③, 3 for each of the front and rear bearings, for a total of 6; 3 for each of the front and rear bearings, for a total of 6; 2 for each of No. ⑤, for a total of 4; the response contribution of the target point of the support platform of the unit on the No. ⑥ transfer path is reduced, and it is not used as an alternative vibration source, so the number of optional vibration sources is selected. m =22; based on the steam turbine generator set m A selected vibration source measuring point to the unit support platform n The working condition transfer path analysis equation between the target response measurement points is based on the multi-objective intelligent optimization algorithm of the vibration source measurement point (NSGA-II algorithm parameter selection: population size is 50, maximum evolutionary generation is 100, conventional crossover and mutation probabilities are 0.8 and 0.1 respectively), and the number of optimal vibration source measurement points at different types of transfer paths is selected as 9 ( m in =2, m out =1, m r1 =2, m r2 =2, m f =2, m o =0). Select target response measurement points at four locations on the front, back, left, and right of the unit support platform n =4. Use synchronous data acquisition and analysis instruments to collect vibration displacement, acceleration and target response signals, and observe and record vibration data when the unit is running stably. r =10 operating conditions (variable speed and load) vibration tests are carried out to obtain rich vibration characteristics of the steam turbine generator set and provide basic test data for the subsequent implementation of the transfer path analysis method.

[0027] Figure 1 The coherence coefficients of different numbers of preferred vibration source measurement points to platform 1# measurement point are given. When only one vibration source measurement point is taken for each type of vibration source, m=5, at this time, the coherence coefficient between the preferred vibration source measurement point and the target response measurement point is around 0.6, which cannot reflect the contribution of all vibration sources to the target point; when m =9, the coherence coefficient at different frequencies is close to 0.8, and some frequency points are slightly greater than 0.8, but it cannot truly reflect the contribution of all vibration source measurement points to the target response measurement point. m =9, it can be seen that the coherence coefficients in the main frequency bands are all greater than 0.8, close to or even greater than 0.9, indicating that there are basically no omissions in the selection of vibration source measurement points.

[0028] Figure 2 A comparison of the worst and best condition numbers of the source matrix for different source combinations shows that optimizing the source measurement points significantly reduces the source matrix condition number, effectively avoiding inversion errors caused by matrix pathology. For frequencies where the condition number remains greater than 100 after optimizing the source measurement points, the Tikhonov regularization method is used to enhance the stability of the matrix inversion.

[0029] Depend on Figure 3 From the spectrum cloud diagram of each path to the target response measurement point, it can be seen that the measured value is in good agreement with the value calculated by the transfer path analysis method, indicating that the transfer path analysis method has a good target measurement point response prediction level. Figure 3 The contribution of each path point to the target response measurement point at different frequencies can also be determined. For example, the contribution ranking of the 200Hz vibration path is: m r2 > m r1 > m f > m in > m out Therefore, after solving the key problems existing in the operating condition transfer path analysis method, it is possible to identify and accurately locate the main excitation source and corresponding transfer path of the steam turbine generator set vibration response system, which can provide strong technical support for the control of the steam turbine generator set vibration source and its transfer path.

Claims

1. A method for analyzing vibration transfer paths of a steam turbine generator set with multi-source excitation, characterized by: The specific process of the analysis method is as follows: 1) According to the structure and distribution characteristics of the steam turbine generator set, the types of vibration sources and corresponding transmission paths of the vibration sources are classified; 2) Determine the vibration sources near the steam turbine generator set M Alternative vibration source measurement points, as well as the preliminary location and type of each alternative vibration source measurement point, and from M Any selection m optional vibration source measurement points, and M ≥(2~3)× m ; 3) Build a steam turbine generator set m A selected vibration source measuring point to the unit support platform n The working condition transfer path analysis equation between the target response measurement points; 4) Based on the working condition transfer path analysis equation, at the alternative vibration source measurement point M Through multi-objective intelligent optimization algorithm to select m Optimal vibration source measuring points and the position of each optimal vibration source measuring point; 5) Run the steam turbine generator set under different working conditions and collect data synchronously through vibration sensors m Optimal vibration source measurement points and n The vibration response signal of each target response measurement point is obtained, and then the transfer function matrix is ​​solved using the working condition transfer path analysis equation.

2. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 1, characterized in that: By multiplying the transfer function matrix by the vibration source measurement point input under any working condition, the response prediction, contribution analysis, and identification of the vibration source and the vibration source transmission path from the vibration source measurement point to the target response measurement point can be achieved.

3. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 1 or 2, characterized in that: The transmission path types in step 1) include: ① steam supply pipe vibration excitation → steam inlet pipe → cylinder → unit support platform; ② exhaust pipe vibration excitation → exhaust pipe → cylinder → unit support platform; ③ rotor system → excitation of front and rear bearings of steam turbine → bearing seat → unit support platform; ④ rotor system → excitation of front and rear bearings of generator → bearing seat → unit support platform; ⑤ steam flow excitation in steam turbine → unit cylinder → unit support platform; ⑥ lubricating oil pipe or cooling water pipe → cylinder → unit support platform.

4. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 1 is characterized by: The number of vibration source measurement points selected in step 2) m = m in + m out + m r1 + m r2 + m f + m o ; in, m in is the number of vibration source measurement points in the steam inlet pipe, m out The number of vibration source measurement points on the exhaust pipe, m r1 is the number of turbine side vibration source measurement points near the rotor system bearings, m r2 is the number of generator side vibration source measurement points near the rotor system bearings, m f is the number of vibration source measurement points on the cylinder, m o The number of vibration source measuring points on the lubricating oil pipe or cooling water pipe; The vibration source measurement points of the steam inlet pipe and the exhaust pipe are both of the vibration displacement difference ∆ X (ω), the vibration source measurement points on the turbine side near the rotor system bearings and the generator side are all of vibration acceleration type, and the vibration source measurement points on the cylinder and the lubricating oil pipe or cooling water pipe are all of vibration acceleration type.

5. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 1 is characterized in that: In step 3) the steam turbine generator set m A selected vibration source measuring point to the unit support platform n The operating condition transfer path analysis equation between the target response measurement points is as follows: is the vibration source measurement point matrix, where the elements X ki Indicates the k In the working condition, a The vibration response value of the optimal vibration source measurement point, a =1,2,……, m ; k =1,2,……, r ; when a =1,2,……, m in + m out hour, X ka The value is the difference in vibration displacement ∆ X (ω), the remaining columns X ka The value is the vibration acceleration; is the transfer function matrix, where the elements are T aj Indicates the a The first preferred vibration source measuring point to the j The transfer function between target response measurement points; is the response value matrix of the target response measurement point, where the elements P kj Indicates the k In the working condition, j The response value of each target response measurement point; r is the number of working conditions, and r Greater than m .

6. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 5, characterized in that: In step 4), based on the working condition transfer path analysis equation, at the alternative vibration source measurement point M Through multi-objective intelligent optimization algorithm to select m The specific process of selecting the optimal vibration source measuring point and the location of each optimal vibration source measuring point is as follows: 41) Normalize the response values ​​of the vibration source measurement points on different types of transmission paths and M Any selection from the candidate vibration source measurement points m Select a vibration source measurement point and then calculate m Optional vibration source measurement points to n The re-correlation coefficient of the target response measurement point based on partial coherence is: Where, , For the i Conditional input of vibration source measurement points and target response measurement points p The conditional cross spectrum of For the i The conditional autospectrum of each vibration source measurement point, Indicates the conditional autospectrum of the target response measurement point, conditional input Indicates the least square method from Remove arrive The linear effect of 42) Using the condition number to evaluate the ill-conditioned characteristics of the vibration source measurement point matrix: 43) Determine the two goals of optimizing the vibration source measurement points Min{ , } Select the optimization variable as follows: the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point; The constraints are: γ ≥ 0.8, where at least one vibration source measuring point corresponding to the first to fifth types of vibration source measuring points in step 1) is selected as the preferred vibration source measuring point; 44) Use NSGA-II algorithm to implement iterative optimization of multi-objective intelligent optimization algorithm and determine the number of optimal vibration source measurement points m and the location of each preferred vibration source measurement point.

7. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 5, characterized in that: The formula for solving the transfer function matrix in step 5) is: .

8. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 7, characterized in that: When the hour, Does not exist, use Alternative .

9. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 7, characterized in that: The vibration source measurement point matrix When inverting the matrix, the Tikhonov regularization method is used to deal with the ill-posed problem when inverting the ill-conditioned matrix.

10. The vibration transfer path analysis method for a steam turbine generator set with multi-source excitation according to claim 6, characterized in that: In step 43), at least one vibration source measuring point corresponding to the sixth type of vibration source measuring point in step 1) is selected as a preferred vibration source measuring point or not selected.

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