CN-122020900-A - Marine gas turbine elastic support centering design and test method

CN122020900ACN 122020900 ACN122020900 ACN 122020900ACN-122020900-A

Abstract

The invention relates to the field of gas turbines, in particular to a marine gas turbine elastic support centering design and test method, which comprises the steps of establishing a rotor geometric model containing design parameters based on a rotor design drawing, and calculating a rotor support radial component force according to a rotor global temperature field distribution result, a rotor mechanical constraint and a load application result; and obtaining radial maximum deformation and radial minimum deformation in the extraction area, and calculating the eccentricity based on the radial maximum deformation and the radial minimum deformation to complete the support centering design. According to the invention, through a centering design test, the centering design accuracy can be detected, meanwhile, the actual deformation condition of the elastic support under the action of the rotor gravity is obtained, the loaded support plate and the loading arm can be replaced according to bearing seats with different sizes, and the centering design test has good engineering application value.

Inventors

SUN YONG
PAN HONGWEI
ZHANG LIANG
XU NING
MAO DONGYAN

Assignees

中国船舶集团有限公司第七〇三研究所

Dates

Publication Date: 20260512
Application Date: 20260202

Claims (9)

1. A method of designing a marine gas turbine flexible support centering, the method comprising: S101, establishing a rotor geometric model containing design parameters based on a rotor design drawing, extracting temperature field data from the rotor geometric model to obtain a global temperature field cloud image and discrete temperature data points, matching and assigning the discrete temperature data points to corresponding parts of the rotor geometric model to obtain a rotor thermodynamic analysis model, carrying out thermodynamic solution on the rotor thermodynamic analysis model to obtain a rotor global temperature field distribution result, and calculating a rotor support radial component according to the rotor global temperature field distribution result and a rotor mechanical constraint and load application result after rotor mechanical constraint and load application are established based on the rotor geometric model; s102, constructing an elastic support geometric model by using an elastic support design drawing, dividing the elastic support geometric model into an elastic support grid model by adopting finite element units, establishing constraint conditions, and applying a radial component force of rotor support to the elastic support grid model as a load; S103, solving the elastic support grid model by using a structural statics solver, completing statics calculation of the elastic support structure, extracting key part deformation data in a calculation result, obtaining radial maximum deformation and radial minimum deformation in an extraction area, and completing support centering design based on the radial maximum deformation and the radial minimum deformation.
2. The method for designing the elastic support centering of the marine gas turbine according to claim 1, wherein the step S101 is based on a design drawing of a gas turbine rotor, a three-dimensional modeling technology is adopted to construct an integral rotor geometric model containing rotor shafts, wheel discs at all levels, blades and drums, and the rotor geometric model is embedded into material attribute parameters of all parts of the rotor based on design information of the design drawing; Based on the rotor geometric model and the runner geometric dimension, adopting general CFD software to construct a global flow field-temperature field coupling simulation model containing a rotor through flow region, wherein the global flow field-temperature field coupling simulation model covers a full runner from an air inlet channel to an air outlet channel and containing a rotor and stator gap region, a boundary layer encryption grid is adopted for a near-wall region, and a structured and/or unstructured grid is adopted for a runner region; setting boundary conditions based on design parameters, rated and common typical working condition parameters and working medium physical property parameters in the material attribute parameters; And after the coupling solution is started, extracting the temperature field distribution of the global flow channel, generating a cloud chart of the global temperature field, uniformly selecting discrete measuring points on the surface of the rotor heated part, extracting the temperature values of each measuring point to form discrete temperature data points, and matching the discrete data points with the corresponding parts of the rotor geometric model to obtain the rotor thermodynamic analysis model.
3. The method for designing the elastic support centering of the marine gas turbine according to claim 1, wherein after the rotor thermodynamic analysis model is obtained, the S101 performs thermodynamic solution by adopting a finite element analysis method, and a rotor global temperature field distribution result of the rotor under typical working conditions is obtained by solving a heat conduction equation, wherein the rotor global temperature field distribution result comprises the temperature gradient of each component of the rotor and the thermal expansion quantity of each part.
4. The method for designing the centering of the elastic support of the marine gas turbine according to claim 3, wherein the step S101 is based on a rotor geometric model and establishes mechanical constraint conditions according to the actual support type of the rotor, and specifically, the method comprises the steps of limiting the non-radial freedom degrees of the rotor at the support, including axial displacement and circumferential displacement, and only reserving the radial displacement freedom degrees; Calculating the mass of each component based on the material attribute parameters of all the components of the rotor embedded in the rotor geometric model according to the density and the geometric volume of each component, summarizing to obtain the whole mass of the rotor, applying a gravity load to the rotor model in a gravity field environment, keeping the load direction consistent with the earth gravity direction, and finishing the load application; calculating and extracting component force data of each component supporting position of the rotor along the radial direction based on the rotor global temperature field distribution result, the rotor mechanical constraint and the load application, and taking the component force data as a rotor supporting radial component force; according to the gravity generated by the total mass of all parts of the rotor, carrying out radial force balance verification with the vector of the radial component force of all part supporting positions; Selecting any one part supporting position as a moment fulcrum, verifying moment generated by the mass of each part of the rotor, and performing moment balance verification on the sum of the moment generated by the radial component force of the other part supporting positions; And establishing a data list for the accurate component force along the radial direction of each component supporting position in the calculated rotor supporting radial component force.
5. The method for centering a flexible support of a marine gas turbine according to claim 1, wherein S102 constructs a flexible support geometric model with a flexible support design drawing, and the flexible support geometric model simplifies the secondary structure and retains key structures related to the transition between adjacent cage bars, the cross-section round of the cage bars themselves, and the connection transition between the cage bars and the flange; recording the complete mechanical property parameters of the corresponding materials according to the design drawing, and constructing an elastic support geometric model; The method comprises the steps of selecting finite element units comprising three-dimensional solid units, shell units and/or simplified solid units based on an elastic support geometric model for division, and specifically comprises the steps of dividing cage bar positions into at least three layers of grids in the radial direction, connecting round corners between adjacent cage bars, and round corners of cross sections of the cage bars into at least five layers of grids, enabling the length-width ratio of the whole grid to be not more than five, the torsion degree to be not more than fifteen degrees, and the skew degree to be not more than thirty degrees, gradually encrypting the grids after the finite element units are divided, and repeatedly calculating stress, wherein when the variation of deformation results after grid encryption is smaller than the variation average value, outputting the elastic support grid model.
6. The method for designing the centering of the elastic support of the marine gas turbine according to claim 5, wherein after the elastic support grid model is obtained, all degrees of freedom of the flange surface in a three-dimensional space are limited, the flange surface is prevented from generating axial displacement, radial displacement and circumferential displacement, and simultaneously, corners around three coordinate axes are prevented from being generated, the limiting conditions are used as constraint conditions, and the connecting area of the whole flange is covered after the limiting conditions are added; The rotor supporting radial component force is used as a load and is loaded into the elastic supporting grid model, the loaded load force direction is consistent with the self gravity direction of the rotor, and the method comprises the following steps: Applying a loaded load force to the contact center point and/or the contact line when the rotor component for elastic support is in point contact and/or line contact with the bearing mating surface; When the rotor component for elastic support is not in point contact and/or line contact with the bearing mating surface, the loaded load force is uniformly distributed on the whole bearing mating surface.
7. The method for designing the elastic support centering of the marine gas turbine according to claim 1, wherein the step S103 is characterized in that an elastic support grid model is solved through a structural statics solver, a first round of solving iteration is started and mechanical equation solving is carried out on the elastic support grid model according to a preset iteration step length by calling the structural statics solver, initial iteration data are obtained, the solving iteration is advanced based on the initial iteration data, residual value is collected in each completed iteration, a residual variation curve is drawn and updated, stress and displacement data of key parts of the elastic support are collected according to a fixed frequency of 10 steps, complete monitoring data are obtained, the complete monitoring data are judged based on convergence conditions, and global mechanical calculation original data when convergence is completed are output; Performing systematic extraction and arrangement on the global mechanical calculation original data to obtain a global deformation cloud image and a global stress distribution cloud image which comprise global deformation and stress distribution data and are generated through post-processing software, and forming calculation results of an original data list based on radial deformation original data of all nodes in the contact surface of the elastic support and the bearing outer ring; And acquiring calculation results comprising the global deformation cloud picture and the global stress distribution cloud picture, extracting key part deformation data in the calculation results comprising the global deformation cloud picture and the global stress distribution cloud picture, acquiring the maximum deformation in the radial direction and the minimum deformation in the radial direction, and recording the space positions corresponding to the maximum deformation and the minimum deformation.
8. The method for designing the elastic support centering of the marine gas turbine according to claim 7, wherein the maximum deformation amount and the minimum deformation amount are added based on an arithmetic average method, the sum is divided by two, the calculation result is used as an eccentric distance value required by the eccentric structure, the offset direction of the elastic support deformation is determined according to the space positions corresponding to the maximum deformation amount and the minimum deformation amount, the eccentric direction is consistent with the offset direction, the obtained eccentric distance value is used as an actual offset dimension of the eccentric structure, and the support centering design is completed.
9. A test method for designing a flexible support centering of a marine gas turbine, which is applied to the design method for designing the flexible support centering of the marine gas turbine according to any one of claims 1 to 8, and is characterized in that the test method comprises the following steps: The method comprises the steps that firstly, a loaded support plate is mounted on a fixed base, the loaded support plate is positioned through bolts, an elastic support is mounted on the loaded support plate in a mode that the elastic support rotates 180 degrees according to the mounting position of a casing, a dial indicator is propped under the elastic support, and pointer readings are zeroed; Step two, the loading force arm is inserted into the force arm supporting seat, the rotating shaft penetrates through the loading force arm and the force arm supporting seat, the two sides of the rotating shaft are tightly clamped through bolts, the dummy shaft penetrates through the loading force arm, and circumferential movement of the dummy shaft is prevented through key connection; And thirdly, enabling the loading wrench to penetrate through the loading force arm, calculating the proportion of the loading force arm, determining the applied torque, checking the pointer reading change condition of the dial indicator, and confirming that the centering design is correct when the pointer reading change is consistent with the eccentricity calculation value.

Description

Marine gas turbine elastic support centering design and test method Technical Field The invention relates to the field of gas turbines, in particular to a marine gas turbine elastic support centering design and test method. Background Elastic support is an important device for adjusting the rotor dynamics in rotating machines. The rigidity of the rotor support system after the elastic support is added is reduced, so that the critical rotation speed of the rotor can be adjusted to avoid the working rotation speed, meanwhile, the elasticity of the elastic support can absorb the vibration transmitted from the rotor support position to the external stator component, and on the contrary, the external vibration can be isolated through the elastic support. In actual operation of the unit, the elastic support is small in rigidity and is stressed by the gravity of the rotor, and the bearing support position is depressed. The elastic support is often used together with the extrusion oil film damper, so that it is very important to ensure that the elastic support is concentric with the outer ring of the extrusion oil film damper when in work, and if the gap is uneven, damage such as damper failure, elastic support stress fatigue and the like can occur due to too small gap. Therefore, a certain eccentric distance exists between the machining center line of the elastic support and the installation positioning surface in structural design so as to ensure that the front and rear support positions are concentric when the rotor works, and the elastic support is concentric with the oil film damper. Disclosure of Invention Aiming at the technical problems in the prior art, the invention provides a design and test method for elastic support centering of a marine gas turbine. The technical scheme for solving the technical problems is as follows, the elastic support centering design method of the marine gas turbine comprises the following steps: S101, establishing a rotor geometric model containing design parameters based on a rotor design drawing, extracting temperature field data from the rotor geometric model to obtain a global temperature field cloud image and discrete temperature data points, matching and assigning the discrete temperature data points to corresponding parts of the rotor geometric model to obtain a rotor thermodynamic analysis model, carrying out thermodynamic solution on the rotor thermodynamic analysis model to obtain a rotor global temperature field distribution result, and calculating a rotor support radial component according to the rotor global temperature field distribution result and a rotor mechanical constraint and load application result after rotor mechanical constraint and load application are established based on the rotor geometric model; s102, constructing an elastic support geometric model by using an elastic support design drawing, dividing the elastic support geometric model into an elastic support grid model by adopting finite element units, establishing constraint conditions, and applying a radial component force of rotor support to the elastic support grid model as a load; S103, solving the elastic support grid model by using a structural statics solver, completing statics calculation of the elastic support structure, extracting key part deformation data in a calculation result, obtaining radial maximum deformation and radial minimum deformation in an extraction area, and completing support centering design based on the radial maximum deformation and the radial minimum deformation. In a preferred embodiment, the step S101 is based on a design drawing of the gas turbine rotor, a three-dimensional modeling technology is adopted to construct an overall rotor geometric model containing rotor shafts, wheel discs, blades and drums at each stage, and the rotor geometric model is embedded into material attribute parameters of all components of the rotor based on design information of the design drawing, including density, specific heat capacity, thermal conductivity, linear expansion coefficient and the like, so as to provide basic data for subsequent thermodynamic calculation; based on a rotor geometric model and runner geometric dimensions, adopting general CFD software to construct a universal flow field-temperature field coupling simulation model comprising a rotor through flow region, wherein the rotor through flow region comprises a blade channel, a wheel disc gap and a drum inner and outer side runner, the universal flow field-temperature field coupling simulation model covers a full runner from an air inlet channel to an air outlet channel and comprises a rotor and stator gap region, boundary layer encryption grids are adopted for near-wall regions such as a blade surface, a wheel disc surface and a drum wall surface, and a runner core region adopts structured and/or unstructured grids; Setting boundary conditions based on design parameters, rated and common typical working condition pa