Single-shaft shafting centering calculation method for gas turbine with self-synchronizing clutch

Abstract

The invention discloses a gas turbine single-shaft shafting centering calculation method with a self-synchronizing clutch, and the method comprises the steps: S1, carrying out the modeling of each rotor, and building a finite element model with a temperature field; s2, taking a generator rotor and an exciter rotor as analysis objects, and optimizing the exciter side bearing elevation d5 under the cold-state working condition; s3, optimizing the elevation d1h of the turbine side bearing of the gas turbine and the elevation d2h of the compressor side bearing of the gas turbine under the thermal state working condition; s4, optimizing the elevation d6 of the high-pressure side bearing of the high-pressure section of the steam turbine, the elevation d7 of the medium-pressure side bearing of the medium-low-pressure section of the steam turbine and the elevation d8 of the low-pressure side bearing of the medium-low-pressure section of the steam turbine under the cold-state working condition; s5, the bending moment of each coupling flange of the whole shafting, the journal bending stress of each bearing position and the specific pressure of each bearing are calculated and rechecked; and S6, the opening value of each coupling flange under the cold-state installation working condition is calculated, and a shafting centering graph is compiled. According to the method, the optimization calculation result can be quickly and accurately obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of gas turbines, and in particular relates to a centering calculation method for a single-shaft shaft system of a gas turbine with a self-synchronizing clutch. Background Art

[0002] Accurate gas turbine shafting alignment effectively reduces unit vibration and noise, while also improving shafting efficiency and reliability. The shafting alignment diagram, compiled based on shafting alignment calculation results, is a key design document guiding on-site shafting alignment work and directly impacts shafting alignment accuracy. Therefore, when calculating shafting alignment data, it is crucial to ensure a realistic calculation model, accurate boundary conditions, and a scientific and effective calculation method to achieve accurate results.

[0003] The single-shaft gas turbine system with self-synchronizing clutch is called CGS type single-shaft combined cycle unit system in the industry, which consists of gas turbine, intermediate shaft, generator, exciter, self-synchronizing clutch, high-pressure section of steam turbine and medium- and low-pressure section of steam turbine. Figure 1 The shaft system is about 40.6 meters long and includes 8 radial sliding bearings and 6 coupling flanges. The exciter rotor and the high-pressure section rotor of the turbine are designed with single bearing support. A self-synchronizing clutch is also integrated in the shaft system, which can realize the integration or disengagement of the steam turbine during the operation of the gas turbine.

[0004] Generally, shaft alignment calculations require optimizing the elevation of each bearing in the shaft system to minimize the bending moment of each coupling flange under hot operating conditions. However, for bearings prone to light loads, the bearing elevation may need to be artificially increased to prevent oil film instability. This ensures sufficient bearing pressure to improve bearing stability, provided the flange adjacent to the corresponding bearing does not exceed the design allowable bending moment.

[0005] The calculation requirements and difficulties of aligning the single-shaft system of a gas turbine with a self-synchronizing clutch include: (1) The generator rotor and the exciter rotor are designed as a three-bearing support. The exciter side bearing is a light-loaded bearing. The design elevation of the bearing needs to be given by calculation to increase the bearing pressure ratio; (2) The self-synchronizing clutch used in the shaft system is a semi-rigid coupling. To ensure smooth engagement during operation, the flange center lines on both sides of the self-synchronizing clutch should be ensured to coincide under cold installation conditions; (3) The high-pressure section rotor of the steam turbine is designed as a single-bearing support. During the hot bending moment optimization process, the change in the bearing elevation of the medium and low-pressure section rotors of the steam turbine will cause the flange opening and eccentricity between the high-pressure section rotor of the steam turbine and the self-synchronizing clutch to change, destroying the alignment requirements of the flange center lines on both sides of the self-synchronizing clutch under cold conditions. Therefore, it is necessary to achieve the simultaneous satisfaction of the hot and cold requirements through an algorithm. In addition, there are 8 bearings in the entire shaft system. It is difficult to converge the optimization of 8 bearings at the same time and it is difficult to meet the above requirements at the same time in terms of algorithm. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a single-shaft shaft centering calculation method for a gas turbine with a self-synchronizing clutch, which can quickly and accurately obtain optimization calculation results and avoid the problem of simultaneous optimization of multiple bearings failing to converge.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A method for calculating the centering of a single-shaft shaft system of a gas turbine with a self-synchronizing clutch comprises the following steps:

[0009] S1. Model the gas turbine rotor, intermediate shaft, generator rotor, exciter rotor, self-synchronizing clutch, steam turbine high-pressure section rotor, and steam turbine intermediate and low-pressure section rotors to establish a true equivalent finite element model with temperature field;

[0010] S2. Taking the generator rotor and exciter rotor as analysis objects, optimize the exciter side bearing elevation d5 under the cold installation condition;

[0011] S3. Taking the gas turbine rotor, intermediate shaft, generator rotor and exciter rotor as analysis objects, optimize the gas turbine turbine side bearing elevation d1h and the gas turbine compressor side bearing elevation d2h under hot operating conditions;

[0012] S4. Taking the gas turbine rotor, intermediate shaft, generator rotor, exciter rotor, self-synchronizing clutch, turbine high-pressure section rotor, and turbine intermediate- and low-pressure section rotors as analysis objects, optimize the turbine high-pressure section high-pressure side bearing elevation d6, turbine intermediate- and low-pressure section intermediate- and low-pressure section intermediate- and low-pressure section intermediate- and low-pressure section low-pressure side bearing elevation d8 under cold installation conditions;

[0013] S5. Calculate and verify the bending moment of each coupling flange, the journal bending stress at each bearing position, and the specific pressure of each bearing in the entire shaft system;

[0014] S6. Calculate the opening value of each coupling flange under cold installation conditions and prepare the shaft system centering diagram.

[0015] Furthermore, step S2 is specifically as follows: using the generator combustion side bearing elevation d3 and the generator excitation side bearing elevation d4 under the cold installation condition as the reference elevation for centering, setting d3=0 and d4=0, and optimizing the exciter side bearing elevation d5 under the cold installation condition so that the bending moment of the coupling flange C between the generator rotor and the exciter rotor does not exceed the maximum allowable design bending moment.

[0016] Further, step S3 is specifically as follows: first, according to d3 set in step S2 and combined with the corresponding thermal expansion elevation change Δ3h, the optimized generator engine side bearing elevation d3h under hot operating conditions is obtained, wherein d3h=d3+Δ3h, and according to d4 set in step S2 and combined with the corresponding thermal expansion elevation change Δ4h, the optimized generator excitation side bearing elevation d4h under hot operating conditions is obtained, wherein d4h=d4+Δ4h, and according to d5 optimized in step S2 Combined with the corresponding thermal expansion elevation change Δ5h, the optimized exciter side bearing elevation d5h under hot operating conditions is obtained, where d5h = d5 + Δ5h; then, based on the optimized d3h, d4h and d5h, the gas turbine turbine side bearing elevation d1h and the gas turbine compressor side bearing elevation d2h under hot operating conditions are optimized so that the bending moments of the coupling flange T between the gas turbine rotor and the intermediate shaft and the coupling flange G between the intermediate shaft and the generator rotor meet the requirements.

[0017] Furthermore, in step S3: the bending moments of the coupling flange T between the gas turbine rotor and the intermediate shaft and the coupling flange G between the intermediate shaft and the generator rotor are made to meet the requirements, specifically, the lower opening limits of the coupling flange T and the coupling flange G are both made close to 0.

[0018] Furthermore, in step S4, the optimization calculation of the turbine side shafting needs to simultaneously meet the following two aspects:

[0019] (1) The optimized d6, d7, and d8 need to ensure that the center lines of the coupling flange A and coupling flange B on both sides of the self-synchronizing clutch coincide under the cold installation condition, where coupling flange A is the connection flange between the self-synchronizing clutch and the high-pressure section rotor of the steam turbine, and coupling flange B is the connection flange between the exciter rotor and the self-synchronizing clutch;

[0020] (2) The optimized d6 is combined with the corresponding thermal expansion elevation change Δ6h to convert it into the optimized high-pressure side bearing elevation d6h of the high-pressure section of the steam turbine under hot operating conditions, where d6h=d6+Δ6h. The optimized d7 is combined with the corresponding thermal expansion elevation change Δ7h to convert it into the optimized medium-pressure side bearing elevation d7h of the medium- and low-pressure sections of the steam turbine under hot operating conditions, where d7h=d7+Δ7h. The optimized d8 is combined with the corresponding thermal expansion elevation change Δ8h to convert it into the optimized low-pressure side bearing elevation d8h of the medium- and low-pressure sections of the steam turbine under hot operating conditions, where d8h=d8+Δ8h. The optimized d6h, d7h and d8h need to ensure that the bending moment at the coupling flange S between the high-pressure section rotor and the medium- and low-pressure section rotor of the steam turbine under hot operating conditions is minimized.

[0021] Furthermore, step S4 specifically includes the following sub-steps:

[0022] S4.1. Import the cold installation condition calculation finite element model:

[0023] S4.1.1. Perform the first static calculation;

[0024] S4.1.2. Extract the UY of the node where the center of coupling flange A is located from the calculation results of step S4.1.1. A and ROTZ A , and extract the UY of the node where the center of coupling flange B is located B and ROTZ B , and deduce the eccentricity and opening between coupling flange A and coupling flange B, where UY A Indicates the displacement of coupling flange A in the Y direction, ROTZ A Indicates the rotation angle of coupling flange A around the Z axis, UY B Indicates the displacement of coupling flange B in the Y direction, ROTZ B Indicates the rotation angle of coupling flange B around the Z axis, where the eccentricity between coupling flange A and coupling flange B is ΔUY=UY A -[UY B +Ls×sin(ROTZ B )], where Ls represents the width of the self-synchronizing clutch in the X direction, where the diameters of coupling flange A and coupling flange B are equal and are represented by D, then the opening between coupling flange A and coupling flange B is D×ΔROTZ, where ΔROTZ=ROTZ A -ROTZ B ;

[0025] S4.1.3. Exit the statics calculation module;

[0026] S4.2. Import the finite element model for hot operation calculation:

[0027] S4.2.1. Perform a second static calculation;

[0028] S4.2.2. Extract the lower opening of the coupling flange S from the calculation results of step S4.2.1;

[0029] S4.2.3. Exit the statics calculation module;

[0030] S4.3. Enter the optimization analysis module:

[0031] S4.3.1. Use d6, d7, and d8 as design variables and assign initial values;

[0032] S4.3.2. Set the eccentricity and gap between coupling flange A and coupling flange B in step S4.1.2 as state variables;

[0033] S4.3.3. Set the lower opening of the coupling flange S in step S4.2.2 as the optimization objective function;

[0034] S4.3.4. Perform optimization calculations to obtain the optimal solutions for d6, d7, and d8, thereby optimizing d6, d7, and d8.

[0035] Furthermore, step S4.3.1 is specifically as follows: the initial values of the design variables d6, d7 and d8 are obtained by the arc length formula, where d6 = dB + L1 × sin (ROTZ B ), d7=dB+(L1+L2)×sin(ROTZ B ), d8=dB+(L1+L2+L3)×sin(ROTZ B ), where dB represents the coordinate value in the Y direction of the node where the center of the coupling flange B is located in the cold installation condition calculated under the optimal solution of step S3, where L1 represents the distance between the X-coordinate of the node where the center of the coupling flange B is located and the X-coordinate of the node where the center of the high-pressure side bearing of the high-pressure section of the turbine is located, L2 represents the distance between the X-coordinate of the node where the center of the high-pressure side bearing of the high-pressure section of the turbine is located and the X-coordinate of the node where the center of the medium-pressure side bearing of the medium- and low-pressure section of the turbine is located, and L3 represents the distance between the X-coordinate of the node where the center of the medium-pressure side bearing of the medium- and low-pressure section of the turbine is located and the X-coordinate of the node where the center of the low-pressure side bearing of the medium- and low-pressure section of the turbine is located.

[0036] Further,

[0037] In step S4.3.2: the state variable is defined as ΔUY = UY A -[UY B +Ls×sin(ROTZ B)]→0, ΔROTZ=ROTZ A -ROTZ B →0;

[0038] In step S4.3.3: the objective function is defined as the lower opening limit of the coupling flange S is close to 0.

[0039] Furthermore, step S5 is specifically as follows: according to the optimized d6, the high-pressure side bearing elevation d6h of the high-pressure section of the steam turbine under the optimized hot operating condition is obtained; according to the optimized d7, the medium-pressure side bearing elevation d7h of the medium- and low-pressure section of the steam turbine under the optimized hot operating condition is obtained; according to the optimized d8, the low-pressure side bearing elevation d8h of the medium- and low-pressure section of the steam turbine under the optimized hot operating condition is obtained; the optimized d1h-d8h are assigned to the finite element model, and the bending moment of each coupling flange of the entire shaft system, the journal bending stress of each bearing position and the specific pressure of each bearing are calculated under the hot operating condition to ensure that the design requirements are met.

[0040] Further, step S6 is specifically as follows: according to the optimized d1h and the corresponding thermal expansion elevation change Δ1h, the optimized gas turbine turbine side bearing elevation d1 under the cold installation condition is obtained, wherein d1=d1h-Δ1h; according to the optimized d2h and the corresponding thermal expansion elevation change Δ2h, the optimized gas turbine compressor side bearing elevation d2 under the cold installation condition is obtained, wherein d2=d2h-Δ2h; the optimized d1-d8 are assigned to the finite element model, and the gas turbine rotor, intermediate shaft, generator rotor, exciter rotor, self-synchronizing clutch, and turbine are deleted. The temperature field of the high-pressure section rotor and the medium- and low-pressure section rotors of the turbine are calculated. Gravitational acceleration is applied. The nodes where the centers of the coupling flanges are located constrain the three degrees of freedom of UX, UY, and UZ, and do not constrain the three degrees of freedom of ROTX, ROTY, and ROTZ. Static calculations are carried out to obtain the opening values of each coupling flange, and a shaft centering diagram is compiled. The optimized d3 is the d3 set in step S2, and the optimized d4 is the d4 set in step S2. UX represents the displacement of the coupling flange in the X direction, UY represents the displacement of the coupling flange in the Y direction, and UZ represents the displacement of the coupling flange in the Z direction.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch of the present invention comprises the following steps: S1, modeling the gas turbine rotor, intermediate shaft, generator rotor, exciter rotor, self-synchronizing clutch, steam turbine high-pressure section rotor, and steam turbine intermediate and low-pressure section rotors to establish a true equivalent finite element model with a temperature field; S2, taking the generator rotor and exciter rotor as analysis objects, optimizing the exciter side bearing elevation d5 under cold installation conditions; S3, taking the gas turbine rotor, intermediate shaft, generator rotor, and exciter rotor as analysis objects, optimizing the gas turbine turbine side bearing elevation d5 under hot operating conditions. 1h and the bearing elevation d2h on the compressor side of the gas turbine; S4. Taking the gas turbine rotor, intermediate shaft, generator rotor, exciter rotor, self-synchronizing clutch, turbine high-pressure section rotor and turbine intermediate and low-pressure section rotor as the analysis objects, optimize the high-pressure side bearing elevation d6 of the high-pressure section of the steam turbine, the intermediate-pressure side bearing elevation d7 of the intermediate and low-pressure section of the steam turbine and the low-pressure side bearing elevation d8 of the intermediate and low-pressure section of the steam turbine under the cold installation condition; S5. Calculate and verify the bending moment of each coupling flange of the entire shaft system, the journal bending stress of each bearing position and the specific pressure of each bearing; S6. Calculate the opening value of each coupling flange under the cold installation condition and prepare the shaft system centering drawing. This allows for quick and accurate optimization calculation results, avoiding the problem of non-convergence when optimizing multiple bearings simultaneously. Furthermore, the optimization calculation results ensure the stability of the exciter-side bearing, which is a lightly loaded bearing, and the minimum bending moment requirement for each coupling flange under hot operating conditions. This makes the shafting performance safer and more reliable, and the entire calculation method is easy to modify and reuse, resulting in high computational efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the arrangement of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to the present invention;

[0044] Figure 2 This is a flow chart of a calculation method for centering a single-shaft shaft system of a gas turbine with a self-synchronizing clutch according to the present invention;

[0045] Figure 3 Schematic diagram for determining the initial values of design variables d6, d7, and d8 based on the arc length formula;

[0046] Figure 4 The present invention is a flow chart of the turbine side shafting centering calculation based on the finite element model.

[0047] Explanation of the reference numerals in the figure: 10, gas turbine, 20, intermediate shaft, 30, generator, 40, exciter, 50, self-synchronizing clutch, 60, high-pressure section of steam turbine, 70, medium- and low-pressure sections of steam turbine, 1, turbine side bearing of gas turbine, 2, compressor side bearing of gas turbine, 3, turbine side bearing of generator, 4, exciter side bearing of generator, 5, exciter side bearing, 6, high-pressure side bearing of high-pressure section of steam turbine, 7, medium-pressure side bearing of medium- and low-pressure sections of steam turbine, 8, low-pressure side bearing of medium- and low-pressure sections of steam turbine. DETAILED DESCRIPTION

[0048] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0049] The schematic diagram of the single-shaft arrangement of the gas turbine with a self-synchronizing clutch in the present invention is shown in FIG. Figure 1 ,and Figure 1 The axis arrangement diagram in contains the coordinate system.

[0050] The present invention stipulates that the numbers and variables of each bearing in the single-shaft shaft system of the gas turbine with a self-synchronizing clutch are shown in Table 1.

[0051] Table 1 Number and variable definition of each bearing

[0052]

[0053] It is also agreed that the connecting flange between the gas turbine 10 rotor and the intermediate shaft 20 is the coupling flange T, the connecting flange between the intermediate shaft 20 and the generator 30 rotor is the coupling flange G, the connecting flange between the generator 30 rotor and the exciter 40 rotor is the coupling flange C, the connecting flange between the exciter 40 rotor and the self-synchronizing clutch 50 is the coupling flange B, the connecting flange between the self-synchronizing clutch 50 and the turbine high-pressure section 60 rotor is the coupling flange A, and the connecting flange between the turbine high-pressure section 60 rotor and the turbine medium- and low-pressure section 70 rotor is the coupling flange S.

[0054] like Figure 2 As shown, a method for calculating the centering of a single-shaft shaft system of a gas turbine with a self-synchronizing clutch comprises the following steps:

[0055] S1. Modeling the gas turbine 10 rotor, the intermediate shaft 20, the generator 30 rotor, the exciter 40 rotor, the self-synchronizing clutch 50, the steam turbine high-pressure section 60 rotor, and the steam turbine intermediate- and low-pressure section 70 rotor, and establishing a true equivalent finite element model with a temperature field;

[0056] S2. Taking the rotor of the generator 30 and the rotor of the exciter 40 as analysis objects, optimize the elevation d5 of the exciter side bearing 5 under the cold installation condition;

[0057] S3. Taking the gas turbine 10 rotor, intermediate shaft 20, generator 30 rotor, and exciter 40 rotor as analysis objects, optimize the gas turbine turbine side bearing 1 elevation d1h and the gas turbine compressor side bearing 2 elevation d2h under hot operating conditions;

[0058] S4. Taking the gas turbine rotor 10, intermediate shaft 20, generator rotor 30, exciter rotor 40, self-synchronizing clutch 50, turbine high-pressure section rotor 60, and turbine intermediate- and low-pressure section rotor 70 as analysis objects, optimize the elevation d6 of the high-pressure side bearing 6 of the high-pressure section of the turbine, the elevation d7 of the intermediate- and low-pressure section bearing 7 of the turbine, and the elevation d8 of the low-pressure side bearing 8 of the intermediate- and low-pressure section of the turbine under cold installation conditions;

[0059] S5. Calculate and verify the bending moment of each coupling flange, the journal bending stress at each bearing position, and the specific pressure of each bearing in the entire shaft system;

[0060] S6. Calculate the opening value of each coupling flange under cold installation conditions and prepare the shaft system centering diagram.

[0061] Step S1 specifically includes: modeling the gas turbine 10 rotor, the intermediate shaft 20, the generator 30 rotor, the exciter 40 rotor, the self-synchronizing clutch 50, the steam turbine high-pressure section 60 rotor, and the steam turbine intermediate- and low-pressure section 70 rotor to ensure that the lateral stiffness and mass characteristics of each rotor are accurately reflected, and establishing a true equivalent finite element model with a temperature field based on the modeling data of each rotor;

[0062] Specifically, step S2 involves using the elevation d3 of the generator's combustion-turbine-side bearing 3 and the elevation d4 of the generator's exciter-side bearing 4 under cold installation conditions as the reference elevations for centering, setting d3 = 0 and d4 = 0, and optimizing the elevation d5 of the exciter-side bearing 5 under cold installation conditions to ensure that the bending moment of the coupling flange C between the rotors of the generator 30 and the exciter 40 does not exceed the maximum allowable design bending moment. This step ensures that d5 is raised as much as possible without exceeding the maximum allowable design bending moment of the coupling flange C, thereby preventing light loading on the exciter 40 rotor bearing, i.e., the exciter-side bearing 5.

[0063] Among them, step S3 is specifically as follows: first, according to the d3 set in step S2 and combined with the corresponding thermal expansion elevation change Δ3h, the optimized generator engine side bearing 3 elevation d3h under the hot operating condition is obtained, wherein d3h=d3+Δ3h, and according to the d4 set in step S2 and combined with the corresponding thermal expansion elevation change Δ4h, the optimized generator excitation side bearing 4 elevation d4h under the hot operating condition is obtained, wherein d4h=d4+Δ4h, and according to the d5 optimized in step S2 and combined with the corresponding The thermal expansion height change Δ5h is calculated to obtain the optimized height d5h of the exciter-side bearing 5 under hot operating conditions, where d5h = d5 + Δ5h. Then, based on the optimized d3h, d4h, and d5h, the height d1h of the gas turbine-side bearing 1 and the height d2h of the gas turbine-side bearing 2 under hot operating conditions are optimized to ensure that the bending moments of the coupling flange T between the gas turbine 10 rotor and the intermediate shaft 20, and the coupling flange G between the intermediate shaft 20 and the generator 30 rotor, meet the requirements. Preferably, in step S3, the bending moments of the coupling flange T between the gas turbine 10 rotor and the intermediate shaft 20, and the coupling flange G between the intermediate shaft 20 and the generator 30 rotor, meet the requirements, specifically by ensuring that the lower opening limits of the coupling flange T and the coupling flange G are both close to zero. In the optimization analysis method of this step, the state variables are constrained so that the lower opening limits of the coupling flange T and the coupling flange G are both close to 0. Compared with the constraint bending moment which requires multiple iterative calculations, this method can achieve one-step optimization.

[0064] In step S4, the optimization calculation of the turbine side shafting needs to meet the following two aspects at the same time:

[0065] (1) The optimized d6, d7, and d8 need to ensure that the center lines of the coupling flange A and the coupling flange B on both sides of the self-synchronizing clutch 50 coincide under the cold installation condition, where the coupling flange A is the connection flange between the self-synchronizing clutch 50 and the rotor of the high-pressure section 60 of the steam turbine, and the coupling flange B is the connection flange between the rotor of the exciter 40 and the self-synchronizing clutch 50;

[0066] (2) The optimized d6 is combined with the corresponding thermal expansion elevation change Δ6h to convert it into the optimized elevation d6h of the high-pressure side bearing 6 of the high-pressure section of the turbine under hot operating conditions, where d6h=d6+Δ6h. The optimized d7 is combined with the corresponding thermal expansion elevation change Δ7h to convert it into the optimized elevation d7h of the intermediate-pressure side bearing 7 of the intermediate- and low-pressure sections of the turbine under hot operating conditions, where d7h=d7+Δ7h. The optimized d8 is combined with the corresponding thermal expansion elevation change Δ8h to convert it into the optimized elevation d8h of the low-pressure side bearing 8 of the intermediate- and low-pressure sections of the turbine under hot operating conditions, where d8h=d8+Δ8h. The optimized d6h, d7h and d8h need to ensure that the bending moment at the coupling flange S between the rotor of the high-pressure section 60 of the turbine and the rotor of the intermediate- and low-pressure section 70 of the turbine under hot operating conditions is minimized.

[0067] Among them, Figure 4 As shown, step S4 specifically includes the following sub-steps:

[0068] S4.1. Import the cold installation condition calculation finite element model:

[0069] S4.1.1. Perform the first static calculation;

[0070] S4.1.2. Extract the UY of the node where the center of coupling flange A is located from the calculation results of step S4.1.1. A and ROTZ A , and extract the UY of the node where the center of coupling flange B is located B and ROTZ B , and deduce the eccentricity and opening between coupling flange A and coupling flange B, where UY A Indicates the displacement of coupling flange A in the Y direction, ROTZ A Indicates the rotation angle of coupling flange A around the Z axis, UY B Indicates the displacement of coupling flange B in the Y direction, ROTZ B Indicates the rotation angle of coupling flange B around the Z axis, where the eccentricity between coupling flange A and coupling flange B is ΔUY=UY A -[UY B +Ls×sin(ROTZ B )], where Ls represents the width of the self-synchronizing clutch 50 along the X direction, where the diameters of the coupling flange A and the coupling flange B are equal and are represented by D, then the opening between the coupling flange A and the coupling flange B is D×ΔROTZ, where ΔROTZ=ROTZ A -ROTZ B ;

[0071] S4.1.3. Exit the statics calculation module;

[0072] S4.2. Import the finite element model for hot operation calculation:

[0073] S4.2.1. Perform a second static calculation;

[0074] S4.2.2. Extract the lower opening of the coupling flange S from the calculation results of step S4.2.1;

[0075] S4.2.3. Exit the statics calculation module;

[0076] S4.3. Enter the optimization analysis module:

[0077] S4.3.1. Use d6, d7, and d8 as design variables and assign initial values;

[0078] S4.3.2. Set the eccentricity and gap between coupling flange A and coupling flange B in step S4.1.2 as state variables;

[0079] S4.3.3. Set the lower opening of the coupling flange S in step S4.2.2 as the optimization objective function;

[0080] S4.3.4. Perform optimization calculations to obtain the optimal solutions for d6, d7, and d8, thereby optimizing d6, d7, and d8.

[0081] Step S4.3.1 is as follows: Calculate the initial values of design variables d6, d7, and d8 using the arc length formula, where d6 = dB + L1 × sin (ROTZ B ), d7=dB+(L1+L2)×sin(ROTZ B ), d8=dB+(L1+L2+L3)×sin(ROTZ B ), where dB represents the coordinate value in the Y direction of the node where the center of the coupling flange B is located in the cold installation condition calculated under the optimal solution of step S3, where L1 represents the distance between the X-axis coordinate of the node where the center of the coupling flange B is located and the X-axis coordinate of the node where the center of the high-pressure side bearing 6 of the high-pressure section of the turbine is located, L2 represents the distance between the X-axis coordinate of the node where the center of the high-pressure side bearing 6 of the high-pressure section of the turbine is located and the X-axis coordinate of the node where the center of the medium-pressure side bearing 7 of the medium-low-pressure section of the turbine is located, and L3 represents the distance between the X-axis coordinate of the node where the center of the medium-pressure side bearing 7 of the medium-low-pressure section of the turbine is located and the X-axis coordinate of the node where the center of the low-pressure side bearing 8 of the medium-low-pressure section of the turbine is located, see Figure 3 By using the arc length formula to initially assign values to the design variables d6, d7, and d8, it is possible to ensure that d6, d7, and d8 obtained by the optimization calculation in step S4.3.4 are near the optimal solution, and the optimal solution of d6, d7, and d8 can be obtained, so the optimization calculation is very easy to converge.

[0082] in,

[0083] In step S4.3.2: the state variable is defined as ΔUY = UY A -[UY B +Ls×sin(ROTZ B )]→0, ΔROTZ=ROTZ A -ROTZ B →0;

[0084] In step S4.3.3: the objective function is defined as the lower opening limit of the coupling flange S is close to 0.

[0085] Among them, step S5 is specifically: assigning the optimized d1h-d8h to the finite element model, calculating the bending moment of each coupling flange of the entire shaft system under hot operating conditions, the journal bending stress at each bearing position and the specific pressure of each bearing to ensure that the design requirements are met.

[0086] Step S6 specifically includes: obtaining the optimized elevation d1 of the turbine side bearing 1 of the gas turbine under the cold installation condition according to the optimized d1h and the corresponding thermal expansion elevation change Δ1h, wherein d1=d1h-Δ1h; obtaining the optimized elevation d2 of the compressor side bearing 2 of the gas turbine under the cold installation condition according to the optimized d2h and the corresponding thermal expansion elevation change Δ2h, wherein d2=d2h-Δ2h; assigning the optimized d1-d8 to the finite element model, deleting the rotor of the gas turbine 10, the intermediate shaft 20, the rotor of the generator 30, the rotor of the exciter 40, and the self-synchronizing clutch 50. , the temperature field of the turbine high-pressure section 60 rotor and the turbine medium- and low-pressure section 70 rotor, applying gravity acceleration, the nodes where the centers of the coupling flanges are located constrain the three degrees of freedom UX, UY, and UZ, and do not constrain the three degrees of freedom ROTX, ROTY, and ROTZ, carry out static calculations, obtain the opening values of each coupling flange, and compile the shafting centering diagram, where the optimized d3 is the d3 set in step S2, and the optimized d4 is the d4 set in step S2, where UX represents the displacement of the coupling flange in the X direction, UY represents the displacement of the coupling flange in the Y direction, and UZ represents the displacement of the coupling flange in the Z direction.

[0087] The calculation method of the present invention ensures the convergence of the calculation through a stage-by-stage and step-by-step optimization approach.

[0088] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch, characterized in that: The following steps are involved: S1. Modeling the gas turbine (10) rotor, the intermediate shaft (20), the generator (30) rotor, the exciter (40) rotor, the self-synchronizing clutch (50), the steam turbine high-pressure section (60) rotor, and the steam turbine medium- and low-pressure section (70) rotor to establish a true equivalent finite element model with a temperature field; S2, taking the generator (30) rotor and the exciter (40) rotor as analysis objects, optimizing the elevation d5 of the exciter side bearing (5) under the cold installation condition; S3, taking the gas turbine (10) rotor, the intermediate shaft (20), the generator (30) rotor and the exciter (40) rotor as analysis objects, optimizing the gas turbine turbine side bearing (1) elevation d1h and the gas turbine compressor side bearing (2) elevation d2h under hot operating conditions; S4, taking the gas turbine (10) rotor, the intermediate shaft (20), the generator (30) rotor, the exciter (40) rotor, the self-synchronizing clutch (50), the turbine high-pressure section (60) rotor, and the turbine intermediate- and low-pressure section (70) rotor as analysis objects, optimizing the elevation d6 of the high-pressure side bearing (6) of the turbine high-pressure section, the elevation d7 of the intermediate- and low-pressure section bearing (7), and the elevation d8 of the low-pressure side bearing (8) of the turbine intermediate- and low-pressure section under cold installation conditions; S5. Calculate and verify the bending moment of each coupling flange, the journal bending stress at each bearing position, and the specific pressure of each bearing in the entire shaft system; S6. Calculate the opening value of each coupling flange under cold installation conditions and prepare the shaft system centering diagram.

2. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 1, characterized in that: Step S2 specifically comprises: taking the generator combustion engine side bearing (3) elevation d3 and the generator excitation side bearing (4) elevation d4 under the cold installation condition as the reference elevation for centering, setting d3=0 and d4=0, optimizing the exciter side bearing (5) elevation d5 under the cold installation condition, so that the bending moment of the coupling flange C between the generator (30) rotor and the exciter (40) rotor does not exceed the maximum allowable design bending moment.

3. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 2, characterized in that: Step S3 is specifically as follows: first, according to d3 set in step S2 and combined with the corresponding thermal expansion elevation change Δ3h, the optimized hot running condition generator engine side bearing (3) elevation d3h is obtained, wherein d3h=d3+Δ3h, and according to d4 set in step S2 and combined with the corresponding thermal expansion elevation change Δ4h, the optimized hot running condition generator excitation side bearing (4) elevation d4h is obtained, wherein d4h=d4+Δ4h, and according to d5 optimized in step S2 and combined with the corresponding thermal expansion elevation change The optimized height d5h of the exciter side bearing (5) under the hot operating condition is obtained by measuring Δ5h, wherein d5h=d5+Δ5h; and then the height d1h of the gas turbine side bearing (1) and the height d2h of the gas turbine compressor side bearing (2) under the hot operating condition are optimized based on the optimized d3h, d4h and d5h, so that the bending moments of the coupling flange T between the gas turbine (10) rotor and the intermediate shaft (20) and the coupling flange G between the intermediate shaft (20) and the generator (30) rotor both meet the requirements.

4. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 3, characterized in that: In step S3: the bending moments of the coupling flange T between the gas turbine (10) rotor and the intermediate shaft (20) and the coupling flange G between the intermediate shaft (20) and the generator (30) rotor are made to meet the requirements, specifically, the lower opening limits of the coupling flange T and the coupling flange G are both close to 0.

5. The method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 1, characterized in that: In step S4, the optimization calculation of the turbine side shafting needs to meet the following two aspects simultaneously: (1) The optimized d6, d7 and d8 need to ensure that the center lines of the coupling flange A and the coupling flange B on both sides of the self-synchronizing clutch (50) coincide with each other under the cold installation condition, wherein the coupling flange A is the connection flange between the self-synchronizing clutch (50) and the rotor of the high-pressure section (60) of the steam turbine, and wherein the coupling flange B is the connection flange between the rotor of the exciter (40) and the self-synchronizing clutch (50); (2) The optimized d6 is combined with the corresponding thermal expansion elevation change Δ6h to convert it into the optimized elevation d6h of the high-pressure side bearing (6) of the high-pressure section of the steam turbine under hot operating conditions, where d6h=d6+Δ6h. The optimized d7 is combined with the corresponding thermal expansion elevation change Δ7h to convert it into the optimized elevation d7h of the medium-pressure side bearing (7) of the medium- and low-pressure sections of the steam turbine under hot operating conditions, where d7h=d7+Δ7h. The optimized d8 is combined with the corresponding thermal expansion elevation change Δ8h to convert it into the optimized elevation d8h of the low-pressure side bearing (8) of the medium- and low-pressure sections of the steam turbine under hot operating conditions, where d8h=d8+Δ8h. The optimized d6h, d7h and d8h need to ensure that the bending moment at the coupling flange S between the rotor of the high-pressure section (60) of the steam turbine and the rotor of the medium- and low-pressure section (70) of the steam turbine under hot operating conditions is minimized.

6. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 5, characterized in that: Step S4 specifically includes the following sub-steps: S4.

1. Import the cold installation condition calculation finite element model: S4.1.

1. Perform the first static calculation; S4.1.

2. Extract the UY of the node where the center of coupling flange A is located from the calculation results of step S4.1.

1. A and ROTZ A , and extract the UY of the node where the center of coupling flange B is located B and ROTZ B , and deduce the eccentricity and opening between coupling flange A and coupling flange B, where UY A Indicates the displacement of coupling flange A in the Y direction, ROTZ A Indicates the rotation angle of coupling flange A around the Z axis, UY B Indicates the displacement of coupling flange B in the Y direction, ROTZ B Indicates the rotation angle of coupling flange B around the Z axis, where the eccentricity between coupling flange A and coupling flange B is ΔUY=UY A -[UY B +Ls×sin(ROTZ B )], where Ls represents the width of the self-synchronizing clutch (50) along the X direction, where the diameters of the coupling flange A and the coupling flange B are equal and are represented by D, then the opening between the coupling flange A and the coupling flange B is D×ΔROTZ, where ΔROTZ=ROTZ A -ROTZ B ; S4.1.

3. Exit the statics calculation module; S4.

2. Import the finite element model for hot operation calculation: S4.2.

1. Perform a second static calculation; S4.2.

2. Extract the lower opening of the coupling flange S from the calculation results of step S4.2.1; S4.2.

3. Exit the statics calculation module; S4.

3. Enter the optimization analysis module: S4.3.

1. Use d6, d7, and d8 as design variables and assign initial values; S4.3.

2. Set the eccentricity and gap between coupling flange A and coupling flange B in step S4.1.2 as state variables; S4.3.

3. Set the lower opening of the coupling flange S in step S4.2.2 as the optimization objective function; S4.3.

4. Perform optimization calculations to obtain the optimal solutions for d6, d7, and d8, thereby optimizing d6, d7, and d8.

7. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 6, characterized in that: Step S4.3.1 is as follows: Calculate the initial values of design variables d6, d7, and d8 using the arc length formula, where d6 = dB + L1 × sin (ROTZ B ), d7=dB+(L1+L2)×sin(ROTZ B ), d8=dB+(L1+L2+L3)×sin(ROTZ B ), where dB represents the coordinate value in the Y direction of the node where the center of the coupling flange B is located in the cold installation condition calculated under the optimal solution of step S3, where L1 represents the distance between the X-axis coordinate of the node where the center of the coupling flange B is located and the X-axis coordinate of the node where the center of the high-pressure side bearing (6) of the high-pressure section of the turbine is located, L2 represents the distance between the X-axis coordinate of the node where the center of the high-pressure side bearing (6) of the high-pressure section of the turbine is located and the X-axis coordinate of the node where the center of the medium-pressure side bearing (7) of the medium-low-pressure section of the turbine is located, and L3 represents the distance between the X-axis coordinate of the node where the center of the medium-pressure side bearing (7) of the medium-low-pressure section of the turbine is located and the X-axis coordinate of the node where the center of the low-pressure side bearing (8) of the medium-low-pressure section of the turbine is located.

8. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 6, characterized in that: In step S4.3.2: the state variable is defined as ΔUY = UY A -[UY B +Ls×sin(ROTZ B )]→0, ΔROTZ=ROTZ A -ROTZ B →0; In step S4.3.3: the objective function is defined as the lower opening limit of the coupling flange S is close to 0.

9. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 3, characterized in that: Step S5 is specifically as follows: according to the optimized d6, the elevation d6h of the high-pressure side bearing (6) of the high-pressure section of the steam turbine under the optimized hot operating condition is obtained; according to the optimized d7, the elevation d7h of the medium-pressure side bearing (7) of the medium- and low-pressure section of the steam turbine under the optimized hot operating condition is obtained; according to the optimized d8, the elevation d8h of the low-pressure side bearing (8) of the medium- and low-pressure section of the steam turbine under the optimized hot operating condition is obtained; the optimized d1h-d8h are assigned to the finite element model, and the bending moment of each coupling flange of the entire shaft system, the journal bending stress of each bearing position and the specific pressure of each bearing are calculated under the hot operating condition to ensure that the design requirements are met.

10. A method for calculating the centering of a single-shaft gas turbine shaft system with a self-synchronizing clutch according to claim 3, characterized in that: Step S6 is specifically as follows: according to the optimized d1h and the corresponding thermal expansion elevation change Δ1h, the optimized elevation d1 of the turbine side bearing (1) of the gas turbine under the cold installation condition is obtained, wherein d1=d1h-Δ1h; according to the optimized d2h and the corresponding thermal expansion elevation change Δ2h, the optimized elevation d2 of the compressor side bearing (2) of the gas turbine under the cold installation condition is obtained, wherein d2=d2h-Δ2h; the optimized d1-d8 are assigned to the finite element model, and the gas turbine (10) rotor, the intermediate shaft (20), the generator (30) rotor, the exciter (40) rotor, the self-synchronizing clutch ( 50), the temperature field of the turbine high-pressure section (60) rotor and the turbine medium- and low-pressure section (70) rotor, applying gravity acceleration, constraining the three degrees of freedom UX, UY, and UZ at the node where the center of each coupling flange is located, and not constraining the three degrees of freedom ROTX, ROTY, and ROTZ, carrying out static calculations, obtaining the opening value of each coupling flange, and compiling a shaft centering diagram, wherein the optimized d3 is the d3 set in step S2, and the optimized d4 is the d4 set in step S2, wherein UX represents the displacement of the coupling flange in the X direction, UY represents the displacement of the coupling flange in the Y direction, and UZ represents the displacement of the coupling flange in the Z direction.

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