Marine gas turbine elastic support centering design and test method

Abstract

The invention relates to the field of gas turbines, in particular to a marine gas turbine elastic support centering design and test method.The method comprises the steps that a rotor geometric model containing design parameters is established on the basis of a rotor design drawing, and according to a rotor global temperature field distribution result and a rotor mechanical constraint and load applying result, a rotor geometric model is established; calculating a rotor support radial component force; constructing an elastic support geometric model according to the design drawing of the elastic support, and applying the radial component force of the rotor support as a load to the elastic support grid model; and the maximum radial deformation and the minimum radial deformation in the extraction area are obtained, the eccentric distance is calculated based on the maximum radial deformation and the minimum radial deformation, and supporting centering design is completed. Through the centering design test, the accuracy of the centering design can be detected, the actual deformation condition of the elastic support under the action of the gravity of the rotor can be obtained, the loaded support plate and the loading force arm can be replaced according to the bearing seats of different sizes, and the good engineering application value is achieved.

Description

Technical Field

[0001] This invention relates to the field of gas turbines, and more specifically to a design and testing method for a centering elastic support for marine gas turbines. Background Technology

[0002] Elastic supports are an important device for adjusting rotor dynamics in rotating machinery. Adding elastic supports reduces the stiffness of the rotor support system, thereby allowing adjustment of the rotor's critical speed to avoid operating speeds. Simultaneously, the elasticity of the supports absorbs vibrations transmitted from the rotor support location to external stator components; conversely, external vibrations can also be isolated through elastic supports.

[0003] During actual operation of the unit, the elastic support, due to its low stiffness, will sink under pressure due to the rotor's weight. The elastic support is often used in conjunction with a squeeze film damper. Ensuring that the elastic support is concentric with the outer ring of the squeeze film damper during operation is crucial. Uneven clearance can lead to damper failure and stress fatigue of the elastic support due to insufficient clearance.

[0004] Therefore, in the structural design, a certain eccentricity should be considered between the machining center line of the elastic support and the installation positioning surface to ensure that the front and rear support positions are concentric and the elastic support and oil film damper are concentric when the rotor is working. Summary of the Invention

[0005] This invention addresses the technical problems existing in the prior art by providing a design and testing method for centering elastic supports for marine gas turbines.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for centering elastic supports for marine gas turbines, the method comprising: S101. Based on the rotor design drawings, establish a rotor geometric model containing design parameters, extract temperature field data from the rotor geometric model to obtain a global temperature field cloud map and discrete temperature data points, match and assign the discrete temperature data points to the corresponding components of the rotor geometric model to obtain a rotor thermodynamic analysis model, and perform thermodynamic solution on the rotor thermodynamic analysis model to obtain the rotor global temperature field distribution results. Based on the rotor geometric model, establish rotor mechanical constraints and load application, and calculate the rotor support radial component force according to the rotor global temperature field distribution results and the rotor mechanical constraints and load application results. S102. Construct the elastic support geometric model based on the design drawings of the elastic support, divide the elastic support geometric model into an elastic support mesh model using finite element elements, establish constraint conditions, and apply the radial component of the rotor support as a load to the elastic support mesh model. S103. Solve the elastic support mesh model using a structural statics solver to complete the statics calculation of the elastic support structure. Extract the deformation data of key parts from the calculation results, obtain the maximum and minimum radial deformation within the extracted area, calculate the eccentricity based on the maximum and minimum radial deformation, and complete the support centering design.

[0007] In a preferred embodiment, S101 is based on the design drawings of the gas turbine rotor, and uses three-dimensional modeling technology to construct an overall rotor geometric model including the rotor shaft, each stage of disks, blades and drum. The rotor geometric model embeds the material property parameters of all rotor components, including density, specific heat capacity, thermal conductivity, linear expansion coefficient, etc., based on the design information of the design drawings, to provide basic data for subsequent thermodynamic calculations. Based on the rotor geometry model and flow channel geometry, a global flow field-temperature field coupled simulation model containing the rotor flow region was constructed using general CFD software. The rotor flow region includes the blade passage, the impeller clearance, and the inner and outer flow channels of the drum. The global flow field-temperature field coupled simulation model covers the entire flow channel from the intake to the exhaust and includes the rotor-stator clearance region. Boundary layer meshing was used to refine the mesh in the near-wall regions such as the blade surface, impeller surface, and drum wall, while the core region of the flow channel used structured and / or unstructured meshing. Boundary conditions are set based on the design parameters, rated and commonly used typical operating condition parameters, and working fluid property parameters in the material property parameters. Specifically, the inlet boundary is set as the total temperature and total pressure inlet, and the corresponding total temperature and total pressure values ​​for the inlet air under the corresponding operating condition are input. At the same time, the airflow inlet angle is set. The outlet boundary is set as the static pressure outlet, and the exhaust back pressure value is input. The wall boundary sets the rotor component wall as the coupled heat transfer boundary, associating the heat transfer between the solid domain and the fluid domain. The stator component wall is set as the isothermal or convective heat transfer boundary according to the actual heat dissipation. The rotation boundary sets a rotating coordinate system for the rotor region, inputs the rotor speed, and simulates the effect of centrifugal force on airflow. After initiating the coupled solution, the global flow channel temperature field distribution is extracted, generating a global temperature field cloud map to visually display the temperature distribution pattern. Discrete measurement points are uniformly selected on the surface of the rotor's heated components, and the temperature values ​​of each measurement point are extracted to form discrete temperature data points. After matching the discrete data points to the corresponding components of the rotor's geometric model, the rotor thermodynamic analysis model is obtained.

[0008] In a preferred embodiment, after obtaining the rotor thermodynamic analysis model, step S101 uses the finite element analysis method to perform thermodynamic solution. By solving the heat conduction equation, the rotor global temperature field distribution result under typical operating conditions is obtained. The rotor global temperature field distribution result includes the temperature gradient of each component of the rotor and the thermal expansion of each part. The temperature gradient is the rate of temperature change at different locations, and the thermal expansion is the dimensional elongation caused by the temperature increase.

[0009] In a preferred embodiment, S101 establishes mechanical constraints based on the rotor geometric model and according to the actual support type of the rotor, such as sliding bearing support, rolling bearing support, floating bearing support, etc. Specifically, it restricts the non-radial degrees of freedom of the rotor at the support, including axial displacement and circumferential displacement, and retains only the radial displacement degree of freedom, so as to accurately simulate the support constraint state of the rotor in actual operation. Based on the material property parameters of all rotor components embedded in the rotor geometric model, the mass of each component is calculated according to its density and geometric volume, and the overall mass of the rotor is obtained by summing them up. Under the gravity field environment, a gravity load is applied to the rotor model, with the load direction consistent with the direction of Earth's gravity, and the load application is completed. Based on the rotor global temperature field distribution results and rotor mechanical constraints and load application, the radial component force data of each rotor component support position is calculated and extracted as the rotor support radial component force; The radial force balance is verified by comparing the total mass of all rotor components with the radial component of the force at each component's support position. The rotor's total weight must cancel out the sum of the upward radial support forces at each support point to ensure that the rotor is in radial force balance, i.e., the two forces must be equal. Select any component support location as the torque fulcrum and verify the torque generated by the mass of each rotor component. Perform torque balance verification by summing the torque generated by the radial component forces at other component support locations. Specifically, there are two cases: First, when the left support point is used as the fulcrum, the torque generated by the mass of all components about the left support point cancels out the torque generated by the radial component forces at the right support point about the left support point. Second, when the right support point is used as the fulcrum, the torque generated by the mass of all components about the right support point cancels out the torque generated by the radial component forces at the left support point about the right support point. If the above force balance or torque balance conditions are not met, it is necessary to retrospectively check the accuracy of the geometric model construction, the rationality of the boundary condition settings, and the accuracy of the load application. After correcting the problems, recalculate until both balance conditions are met. A data list is created by calculating the precise radial component of the radial force of each component support position in the rotor support obtained.

[0010] In a preferred embodiment, the elastic support geometric model is constructed using the design drawings of the elastic support. The elastic support geometric model simplifies the secondary structures and retains the key structures, including the transition fillets between adjacent cage bars, the cross-sectional fillets of the cage bars themselves, and the connection transitions between the cage bars and the flanges. The secondary structures mainly refer to structures that do not affect the deformation characteristics, such as process grooves and marking holes in non-critical parts. Enter the complete mechanical property parameters of the corresponding material according to the design drawings, including elastic modulus, Poisson's ratio, yield strength, density, thermal conductivity, etc., and construct the elastic support geometric model; Based on the elastic support geometric model, finite element elements including three-dimensional solid elements, shell elements, and / or simplified solid elements are selected for meshing. Specifically, the cage bar area is divided into no less than three layers of mesh in the radial direction to ensure accurate capture of the radial deformation gradient. The transition fillets between adjacent cage bars and the fillets of the cage bar sections are divided into no less than five layers of mesh to avoid mesh distortion. The overall mesh aspect ratio does not exceed 5, the twist degree does not exceed 15 degrees, and the skewness does not exceed 30 degrees. All indicators must meet the accuracy requirements of structural statics calculation. After the finite element elements are divided, the mesh is gradually refined and the stress calculation is repeated. When the change in deformation result after mesh refinement is less than the average change, the elastic support mesh model is output.

[0011] In a preferred embodiment, after obtaining the elastic support mesh model, all degrees of freedom of the flange face in three-dimensional space are restricted, prohibiting the flange face from generating axial displacement, radial displacement, and circumferential displacement, and also prohibiting the generation of rotation around the three coordinate axes. This simulates the actual installation state of the elastic support rigidly connected to the casing through the flange without relative motion, serving as a constraint condition. After the constraint condition is added, it covers the entire connection area of ​​the flange to avoid local constraint omissions that could lead to distortion of the calculation results. The radial component of the rotor support is used as the load, which is applied to the elastic support mesh model. The direction of the applied load force is consistent with the direction of the rotor's own gravity, i.e., vertically downward, to ensure that it is consistent with the force direction of the elastic support in actual operation. The following settings are included: When there is a rotor component used for elastic support and the bearing mating surface is in point contact and / or line contact, the applied load force is applied to the contact center point and / or contact line; When the rotor component used for elastic support has a non-point contact and / or line contact with the bearing mating surface, the applied load force will be evenly distributed across the entire bearing mating surface.

[0012] In a preferred embodiment, step S103 solves the elastic support mesh model using a structural statics solver. By calling the structural statics solver, the first iteration is initiated, and the mechanical equations of the elastic support mesh model are solved according to a preset iteration step size to obtain initial iteration data. The solution iteration is then advanced based on this initial data. Residual values ​​are collected after each iteration, and the residual change curve is plotted and updated. Stress and displacement data of key parts of the elastic support are collected at a fixed frequency of 10 steps to obtain complete monitoring data. The complete monitoring data is then determined based on convergence conditions, such as checking whether the residual curve tends to stabilize and whether the final residual value is ≤10. -6Check whether the stress / displacement time series curves of key parts are stable and whether the parameter change over 20 consecutive steps is ≤1%. If both conditions are met, the solution is considered converged and the solution is terminated. If only one condition is met, the iteration continues and the solution returns to the second step to update the monitoring data. If the iteration number reaches the preset maximum value and the condition is still not met, the solution is considered non-converged. After the solution is fully converged, the original data of the global mechanical calculation at the time of convergence is output. The original data of the global mechanical calculation are systematically extracted and organized to obtain the calculation results, which include global deformation and stress distribution data, global deformation cloud map and global stress distribution cloud map generated by post-processing software, and the original data of radial deformation of all nodes in the contact surface between the elastic support and the bearing outer ring. Obtain the calculation results including the global deformation cloud map and the global stress distribution cloud map, extract the deformation data of key parts from the calculation results including the global deformation cloud map and the global stress distribution cloud map, obtain the maximum deformation in the radial direction, that is, the maximum value of the radial deformation of all points in the region, and the minimum deformation in the radial direction, that is, the minimum value of the radial deformation of all points in the region, and record the spatial positions corresponding to the maximum deformation and the minimum deformation.

[0013] In a preferred embodiment, the maximum and minimum deformations are added together using the arithmetic mean method, and then the sum is divided by two. The result is used as the eccentricity value required for the eccentric structure. The offset direction of the elastic support deformation is determined according to the spatial position corresponding to the maximum and minimum deformations. The eccentricity direction is consistent with the offset direction. The obtained eccentricity value is used as the actual offset size of the eccentric structure, thus completing the support centering design.

[0014] The present invention also provides a test method for the centering design of elastic supports for marine gas turbines, the test method comprising the following steps: Step 1: Install the load-bearing support plate onto the fixed base and position it with bolts. Rotate the elastic support 180° according to the housing installation position and install it on the load-bearing support plate. Place the dial indicator directly below the elastic support and set the pointer reading to zero. Step 2: Insert the loading arm into the arm support seat, pass the rotating shaft through the loading arm and the arm support seat, tighten the rotating shaft on both sides with bolts, and pass the dummy shaft through the loading arm. Connect it with a key to prevent the dummy shaft from moving around in the circumference. Step 3: Pass the loading wrench through the loading arm, calculate the loading arm ratio, determine the magnitude of the applied torque, and observe the change in the dial indicator reading. If the change in the dial indicator reading is consistent with the calculated value of the eccentricity, it confirms that the centering design is correct.

[0015] The beneficial effects of this invention are: the centering design of the elastic support can pre-adjust the concentricity of the front and rear support positions, and the concentricity of the elastic support and the oil film damper, ensuring good rotor alignment, reducing the imbalance caused by eccentricity, and ensuring the proper functioning of the oil film damper. Through the centering design test, the accuracy of the centering design can be detected, and the actual deformation of the elastic support under the rotor's gravity can be obtained. The load-bearing support plate and loading lever arm can be replaced according to different sized bearing seats, which has good engineering application value. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a schematic diagram of the test device for the elastic support centering design used in this invention.

[0017] In the diagram: 1. Fixed base; 2. Load-bearing support plate; 3. Loading lever arm; 4. Dummy shaft; 5. Lever arm support seat; 6. Rotating shaft; 7. Loading wrench; 8. Dial indicator; 9. Elastic support; 10. Bearing. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] As attached Figure 1-2 As shown in this embodiment, a method for centering elastic supports for marine gas turbines is provided, the method comprising: S101. Based on the rotor design drawings, establish a rotor geometric model containing design parameters, extract temperature field data from the rotor geometric model to obtain a global temperature field cloud map and discrete temperature data points, match and assign the discrete temperature data points to the corresponding components of the rotor geometric model to obtain a rotor thermodynamic analysis model, and perform thermodynamic solution on the rotor thermodynamic analysis model to obtain the rotor global temperature field distribution results. Based on the rotor geometric model, establish rotor mechanical constraints and load application, and calculate the rotor support radial component force according to the rotor global temperature field distribution results and the rotor mechanical constraints and load application results. Based on the design drawings of the gas turbine rotor, a three-dimensional modeling technology was used to construct an overall rotor geometric model including the rotor shaft, each stage of disks, blades, and drum. The rotor geometric model embeds the material property parameters of all rotor components, including density, specific heat capacity, thermal conductivity, and coefficient of linear expansion, based on the design information in the design drawings, to provide basic data for subsequent thermodynamic calculations. Based on the rotor geometry model and flow channel geometry, a global flow field-temperature field coupled simulation model containing the rotor flow region was constructed using general CFD software. The rotor flow region includes the blade passage, the impeller clearance, and the inner and outer flow channels of the drum. The global flow field-temperature field coupled simulation model covers the entire flow channel from the intake to the exhaust and includes the rotor-stator clearance region. Boundary layer meshing was used to refine the mesh in the near-wall regions such as the blade surface, impeller surface, and drum wall, while the core region of the flow channel used structured and / or unstructured meshing. Boundary conditions are set based on the design parameters, rated and commonly used typical operating condition parameters, and working fluid property parameters in the material property parameters. Specifically, the inlet boundary is set as the total temperature and total pressure inlet, and the corresponding total temperature and total pressure values ​​for the inlet air under the corresponding operating condition are input. At the same time, the airflow inlet angle is set. The outlet boundary is set as the static pressure outlet, and the exhaust back pressure value is input. The wall boundary sets the rotor component wall as the coupled heat transfer boundary, associating the heat transfer between the solid domain and the fluid domain. The stator component wall is set as the isothermal or convective heat transfer boundary according to the actual heat dissipation. The rotation boundary sets a rotating coordinate system for the rotor region, inputs the rotor speed, and simulates the effect of centrifugal force on airflow. After initiating the coupled solution, the global flow channel temperature field distribution is extracted, generating a global temperature field cloud map to visually display the temperature distribution pattern. Discrete measurement points are uniformly selected on the surface of the rotor's heated components, and the temperature values ​​of each measurement point are extracted to form discrete temperature data points. After matching the discrete data points to the corresponding components of the rotor's geometric model, the rotor thermodynamic analysis model is obtained.

[0020] After obtaining the rotor thermodynamic analysis model, the finite element analysis method is used to solve the thermodynamic problem. By solving the heat conduction equation, the rotor global temperature field distribution under typical operating conditions is obtained. The rotor global temperature field distribution includes the temperature gradient of each component of the rotor and the thermal expansion of each part. The temperature gradient is the rate of temperature change at different locations, and the thermal expansion is the dimensional elongation caused by the temperature increase.

[0021] Based on the rotor geometric model and according to the actual support type of the rotor, such as sliding bearing support, rolling bearing support, floating bearing support, etc., mechanical constraints are established. Specifically, the non-radial degrees of freedom of the rotor at the support, including axial displacement and circumferential displacement, are restricted, and only the radial displacement degree of freedom is retained, so as to accurately simulate the support constraint state of the rotor in actual operation. Based on the material property parameters of all rotor components embedded in the rotor geometric model, the mass of each component is calculated according to its density and geometric volume, and the overall mass of the rotor is obtained by summing them up. Under the gravity field environment, a gravity load is applied to the rotor model, with the load direction consistent with the direction of Earth's gravity, and the load application is completed. Based on the rotor global temperature field distribution results and rotor mechanical constraints and load application, the radial component force data of each rotor component support position is calculated and extracted as the rotor support radial component force; The radial force balance is verified by comparing the total mass of all rotor components with the radial component of the force at each component's support position. The rotor's total weight must cancel out the sum of the upward radial support forces at each support point to ensure that the rotor is in radial force balance, i.e., the two forces must be equal. Select any component support location as the torque fulcrum and verify the torque generated by the mass of each rotor component. Perform torque balance verification by summing the torque generated by the radial component forces at other component support locations. Specifically, there are two cases: First, when the left support point is used as the fulcrum, the torque generated by the mass of all components about the left support point cancels out the torque generated by the radial component forces at the right support point about the left support point. Second, when the right support point is used as the fulcrum, the torque generated by the mass of all components about the right support point cancels out the torque generated by the radial component forces at the left support point about the right support point. If the above force balance or torque balance conditions are not met, it is necessary to retrospectively check the accuracy of the geometric model construction, the rationality of the boundary condition settings, and the accuracy of the load application. After correcting the problems, recalculate until both balance conditions are met. A data list is created by calculating the precise radial component of the radial force of each component support position in the rotor support obtained.

[0022] S102. Construct the elastic support geometric model based on the design drawings of the elastic support, divide the elastic support geometric model into an elastic support mesh model using finite element elements, establish constraint conditions, and apply the radial component of the rotor support as a load to the elastic support mesh model. The elastic support geometric model is constructed based on the design drawings of the elastic support. The elastic support geometric model simplifies the secondary structure and retains the key structure, including the transition fillet between adjacent cage bars, the cross-sectional fillet of the cage bar itself, and the connection transition between the cage bar and the flange. The secondary structure mainly refers to the structure that does not affect the deformation characteristics, such as the process groove and marking hole in non-critical parts. Enter the complete mechanical property parameters of the corresponding material according to the design drawings, including elastic modulus, Poisson's ratio, yield strength, density, thermal conductivity, etc., and construct the elastic support geometric model; Based on the elastic support geometric model, finite element elements including three-dimensional solid elements, shell elements, and / or simplified solid elements are selected for meshing. Specifically, the cage bar area is divided into no less than three layers of mesh in the radial direction to ensure accurate capture of the radial deformation gradient. The transition fillets between adjacent cage bars and the fillets of the cage bar sections are divided into no less than five layers of mesh to avoid mesh distortion. The overall mesh aspect ratio does not exceed 5, the twist degree does not exceed 15 degrees, and the skewness does not exceed 30 degrees. All indicators must meet the accuracy requirements of structural statics calculation. After the finite element elements are divided, the mesh is gradually refined and the stress calculation is repeated. When the change in deformation result after mesh refinement is less than the average change, the elastic support mesh model is output.

[0023] After obtaining the elastic support mesh model, all degrees of freedom of the flange face in three-dimensional space are restricted, prohibiting axial, radial, and circumferential displacements of the flange face, and also prohibiting rotation around the three coordinate axes. This simulates the actual installation state of the elastic support rigidly connected to the casing through the flange without relative motion, and serves as a constraint condition. The constraint condition is applied to cover the entire connection area of ​​the flange to avoid local constraint omissions that could lead to distortion of the calculation results. The radial component of the rotor support is used as the load, which is applied to the elastic support mesh model. The direction of the applied load force is consistent with the direction of the rotor's own gravity, i.e., vertically downward, to ensure that it is consistent with the force direction of the elastic support in actual operation. The following settings are included: When there is a rotor component used for elastic support and the bearing mating surface is in point contact and / or line contact, the applied load force is applied to the contact center point and / or contact line; When the rotor component used for elastic support has a non-point contact and / or line contact with the bearing mating surface, the applied load force will be evenly distributed across the entire bearing mating surface.

[0024] S103. Solve the elastic support mesh model using a structural statics solver to complete the statics calculation of the elastic support structure. Extract the deformation data of key parts from the calculation results, obtain the maximum and minimum radial deformation within the extracted area, calculate the eccentricity based on the maximum and minimum radial deformation, and complete the support centering design.

[0025] The elastic support mesh model is solved using a structural statics solver. The first iteration is initiated by calling the structural statics solver, and the mechanical equations of the elastic support mesh model are solved according to a preset iteration step size to obtain initial iteration data. The solution iteration is then advanced based on this initial data. Residual values ​​are collected after each iteration, and the residual change curve is plotted and updated. Stress and displacement data of key parts of the elastic support are collected at a fixed frequency of 10 steps to obtain complete monitoring data. The complete monitoring data is then judged based on convergence conditions, such as checking whether the residual curve tends to stabilize and whether the final residual value is ≤10.-6 Check whether the stress / displacement time series curves of key parts are stable and whether the parameter change over 20 consecutive steps is ≤1%. If both conditions are met, the solution is considered converged and the solution is terminated. If only one condition is met, the iteration continues and the solution returns to the second step to update the monitoring data. If the iteration number reaches the preset maximum value and the condition is still not met, the solution is considered non-converged. After the solution is fully converged, the original data of the global mechanical calculation at the time of convergence is output. The original data of the global mechanical calculation are systematically extracted and organized to obtain the calculation results, which include global deformation and stress distribution data, global deformation cloud map and global stress distribution cloud map generated by post-processing software, and the original data of radial deformation of all nodes in the contact surface between the elastic support and the bearing outer ring. Obtain the calculation results including the global deformation cloud map and the global stress distribution cloud map, extract the deformation data of key parts from the calculation results including the global deformation cloud map and the global stress distribution cloud map, obtain the maximum deformation in the radial direction, that is, the maximum value of the radial deformation of all points in the region, and the minimum deformation in the radial direction, that is, the minimum value of the radial deformation of all points in the region, and record the spatial positions corresponding to the maximum deformation and the minimum deformation.

[0026] The maximum and minimum deformations are added together using the arithmetic mean method, and then the sum is divided by two. The result is used as the eccentricity value required for the eccentric structure. The offset direction of the elastic support deformation is determined according to the spatial position corresponding to the maximum and minimum deformations. The eccentricity direction is consistent with the offset direction. The obtained eccentricity value is used as the actual offset size of the eccentric structure, thus completing the support centering design.

[0027] This invention also provides a test method for the centering design of elastic supports for marine gas turbines, the test method comprising the following steps: Step 1: Install the load-bearing support plate 2 onto the fixed base 1, and position the load-bearing support plate 2 with bolts. Rotate the elastic support 9 180° according to the housing installation position and install it on the load-bearing support plate 2. Place the dial indicator 8 directly below the elastic support 9 and set the pointer reading to zero. Step 2: Insert the loading arm 3 into the arm support 5, and the rotating shaft 6 passes through the loading arm 3 and the arm support 5. The rotating shaft 6 is clamped on both sides by bolts. The dummy shaft 4 passes through the loading arm 3 and is connected by a key to prevent circumferential movement of the dummy shaft 4. Step 3: Pass the loading wrench 7 through the loading arm 3, calculate the ratio of the loading arm 3, determine the magnitude of the applied torque, and check the change in the pointer reading of the dial indicator 8. If the change in the pointer reading is consistent with the calculated value of the eccentricity, it confirms that the centering design is correct.

[0028] In some other specific implementations, the testing process includes: First, based on the matching dimensions of the elastic support 9 and the casing, the load-bearing support plate 2 of suitable size is fixedly installed on the upright of the fixed base 1 with bolts, and the elastic support 9 is fixedly installed on the load-bearing support plate 2 in the opposite direction with bolts.

[0029] Carefully clean the mating surfaces of the elastic support 9 and the outer ring of the bearing 10. Check whether the bearing 10 model is correct and whether there are any defects in its appearance. Use a micrometer to re-measure the outer diameter of the outer ring and the inner diameter of the inner ring of the bearing 10. Re-measure the mating dimensions of the elastic support 9. Gently tap the bearing 10 with a sleeve to install it inside the elastic support 9. Use a feeler gauge to check whether the outer ring of the bearing 10 is completely axially fitted with the elastic support 9.

[0030] Install the key in the keyway of the loading arm 3, and fit the dummy shaft 4 onto the loading arm 3. Use the key to ensure the relative position of the dummy shaft 4 and the loading arm 3. Carefully clean the outer surface of the dummy shaft 4, re-measure the outer diameter of the dummy shaft 4 with a micrometer, insert one side of the dummy shaft 4 into the liquid nitrogen tank for cooling, and after sufficient cooling, insert the dummy shaft 4 into the inner ring of the bearing 10.

[0031] Install the lever arm support 5 so that the round hole of the loading lever arm 3 coincides with the round hole of the lever arm support 5. Insert the rotating shaft 6 and fix the lever arm support 5 to the fixed base 1 with bolts. Insert the square head of the loading wrench 7 into the square hole corresponding to the loading lever arm 3. Attach the dial indicator 8 to the fixed base 1. The dial indicator reading is N1.

[0032] The measured distance L1 from the mid-section of the inner and outer rings of bearing 10 to the rotating shaft is used to calculate the radial component G of the rotor support point. ’ Set the torque of the loading wrench to M=G ’ • L1. Rotate the loading wrench 7 downwards. When you hear a mechanical sound indicating successful docking, check the dial indicator 8. If the reading is N2, and the change in pointer reading ΔN = N2 - N1 is consistent with the calculated eccentricity value, then the centering design is confirmed to be correct.

Claims

1. A method for centering elastic supports for marine gas turbines, characterized in that, The method includes: S101. Based on the rotor design drawings, establish a rotor geometric model containing design parameters, extract temperature field data from the rotor geometric model to obtain a global temperature field cloud map and discrete temperature data points, match and assign the discrete temperature data points to the corresponding components of the rotor geometric model to obtain a rotor thermodynamic analysis model, and perform thermodynamic solution on the rotor thermodynamic analysis model to obtain the rotor global temperature field distribution results. Based on the rotor geometric model, establish rotor mechanical constraints and load application, and calculate the rotor support radial component force according to the rotor global temperature field distribution results and the rotor mechanical constraints and load application results. S102. Construct the elastic support geometric model based on the design drawings of the elastic support, divide the elastic support geometric model into an elastic support mesh model using finite element elements, establish constraint conditions, and apply the radial component of the rotor support as a load to the elastic support mesh model. S103. Solve the elastic support mesh model using a structural statics solver to complete the statics calculation of the elastic support structure. Extract the deformation data of key parts from the calculation results, obtain the maximum and minimum radial deformation within the extracted area, calculate the eccentricity based on the maximum and minimum radial deformation, and complete the support centering design.

2. The method for centering a marine gas turbine with elastic support according to claim 1, characterized in that, The S101 is based on the design drawings of the gas turbine rotor. It uses three-dimensional modeling technology to construct an overall rotor geometric model including the rotor shaft, each stage of disks, blades and drum. The rotor geometric model embeds the material property parameters of all rotor components based on the design information of the design drawings. Based on the rotor geometry model and flow channel geometry, a global flow field-temperature field coupled simulation model containing the rotor flow region was constructed using general CFD software. The global flow field-temperature field coupled simulation model covers the entire flow channel from the intake duct to the exhaust duct and includes the rotor-stator gap region. Boundary layer meshing was used to refine the mesh in the near-wall region, and structured and / or unstructured meshing was used in the flow channel region. Boundary conditions are set based on the design parameters, rated and commonly used typical operating condition parameters, and working fluid property parameters in the material property parameters. After initiating the coupled solution, the global flow channel temperature field distribution is extracted to generate a global temperature field cloud map. Discrete measurement points are uniformly selected on the surface of the rotor's heated components, and the temperature values ​​of each measurement point are extracted to form discrete temperature data points. After matching the discrete data points to the corresponding components of the rotor's geometric model, the rotor thermodynamic analysis model is obtained.

3. The method for centering elastic supports for marine gas turbines according to claim 1, characterized in that, After obtaining the rotor thermodynamic analysis model, S101 uses the finite element analysis method to solve the thermodynamic problem. By solving the heat conduction equation, the rotor global temperature field distribution under typical operating conditions is obtained. The rotor global temperature field distribution includes the temperature gradient of each component of the rotor and the thermal expansion of each part.

4. The centering design method for an elastic support of a marine gas turbine according to claim 3, characterized in that, S101 establishes mechanical constraints based on the rotor geometric model and the actual support type of the rotor. Specifically, it restricts the non-radial degrees of freedom of the rotor at the support, including axial and circumferential displacements, and retains only the radial displacement degree of freedom. Based on the material property parameters of all rotor components embedded in the rotor geometric model, the mass of each component is calculated according to its density and geometric volume, and the overall mass of the rotor is obtained by summing them up. Under the gravity field environment, a gravity load is applied to the rotor model, with the load direction consistent with the direction of Earth's gravity, and the load application is completed. Based on the rotor global temperature field distribution results and rotor mechanical constraints and load application, the radial component force data of each rotor component support position is calculated and extracted as the rotor support radial component force; And the radial force balance is verified by comparing the gravity generated by the total mass of all rotor components with the vector of the radial component force at the support position of all components; Select any component support position as the torque fulcrum, verify the torque generated by the mass of each component of the rotor, and perform torque balance verification by summing the torque generated by the radial component force at the support position of other components; A data list is created by calculating the precise radial component of the radial force of each component support position in the rotor support obtained.

5. The method for centering elastic supports for marine gas turbines according to claim 1, characterized in that, S102 constructs an elastic support geometric model based on the design drawings of the elastic support. The elastic support geometric model simplifies the secondary structure and retains key structures including the transition fillets between adjacent cage bars, the cross-sectional fillets of the cage bars themselves, and the connection transitions between the cage bars and the flanges. Enter the complete mechanical property parameters of the corresponding materials according to the design drawings, and construct the elastic support geometric model; Based on the elastic support geometric model, finite element elements including three-dimensional solid elements, shell elements, and / or simplified solid elements are selected for meshing. Specifically, the cage bar part is divided into no less than three layers of mesh in the radial direction, and the transition fillets between adjacent cage bars and the fillets of the cage bar cross sections are divided into no less than five layers of mesh. The overall mesh aspect ratio does not exceed 5, the twist degree does not exceed 15 degrees, and the skewness does not exceed 30 degrees. After the finite element elements are divided, the mesh is gradually refined and the stress calculation is repeated. When the change in deformation result after mesh refinement is less than the average change, the elastic support mesh model is output.

6. The method for centering a marine gas turbine with an elastic support according to claim 5, characterized in that, After obtaining the elastic support mesh model, restrict all degrees of freedom of the flange face in three-dimensional space, prohibit the flange face from generating axial displacement, radial displacement, and circumferential displacement, and also prohibit the generation of rotation around the three coordinate axes as a constraint condition, and the constraint condition covers the entire connection area of ​​the flange after being added. The radial component of the rotor support is used as a load, which is applied to the elastic support mesh model. The direction of the applied load force is consistent with the direction of the rotor's own gravity, and the following settings are included: When there is a rotor component used for elastic support and the bearing mating surface is in point contact and / or line contact, the applied load force is applied to the contact center point and / or contact line; When the rotor component used for elastic support has a non-point contact and / or line contact with the bearing mating surface, the applied load force will be evenly distributed across the entire bearing mating surface.

7. The method for centering elastic supports for marine gas turbines according to claim 1, characterized in that, S103 solves the elastic support mesh model using a structural statics solver. By calling the structural statics solver, the first round of solution iteration is started, and the mechanical equations of the elastic support mesh model are solved according to the preset iteration step size to obtain initial iteration data. The solution iteration is advanced based on the initial iteration data, and residual values ​​are collected in each round of iteration. The residual change curve is plotted and updated. Stress and displacement data of key parts of the elastic support are collected at a fixed frequency of once every 10 steps to obtain complete monitoring data. The complete monitoring data is determined based on the convergence condition. After complete convergence, the original data of global mechanical calculation at the time of convergence is output. The original data of the global mechanical calculation are systematically extracted and organized to obtain the calculation results, which include global deformation and stress distribution data, global deformation cloud map and global stress distribution cloud map generated by post-processing software, and the original data of radial deformation of all nodes in the contact surface between the elastic support and the bearing outer ring. Obtain the calculation results, including the global deformation cloud map and the global stress distribution cloud map. Extract the deformation data of key parts from the calculation results, including the global deformation cloud map and the global stress distribution cloud map. Obtain the maximum and minimum deformation in the radial direction and record the spatial positions corresponding to the maximum and minimum deformation.

8. The method for centering a marine gas turbine with elastic support according to claim 7, characterized in that, The maximum and minimum deformations are added together using the arithmetic mean method, and then the sum is divided by two. The result is used as the eccentricity value required for the eccentric structure. The offset direction of the elastic support deformation is determined according to the spatial position corresponding to the maximum and minimum deformations. The eccentricity direction is consistent with the offset direction. The obtained eccentricity value is used as the actual offset size of the eccentric structure, thus completing the support centering design.

9. A test method for the centering design of an elastic support for a marine gas turbine, applied to the centering design method for an elastic support for a marine gas turbine as described in any one of claims 1-8, characterized in that, The experimental method includes the following steps: Step 1: Install the load-bearing support plate onto the fixed base and position it with bolts. Rotate the elastic support 180° according to the housing installation position and install it on the load-bearing support plate. Place the dial indicator directly below the elastic support and set the pointer reading to zero. Step 2: Insert the loading arm into the arm support seat, pass the rotating shaft through the loading arm and the arm support seat, tighten the rotating shaft on both sides with bolts, and pass the dummy shaft through the loading arm. Connect it with a key to prevent the dummy shaft from moving around in the circumference. Step 3: Pass the loading wrench through the loading arm, calculate the loading arm ratio, determine the magnitude of the applied torque, and observe the change in the dial indicator reading. If the change in the dial indicator reading is consistent with the calculated value of the eccentricity, it confirms that the centering design is correct.

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