A method and system for anti-rotation plate design

Abstract

The present invention provides a method and system for designing an anti-rotation plate. The method includes: constructing a shaft seal model and determining the length and installation position of the anti-rotation plate based on the shaft seal model and axial displacement; obtaining the swirl ratio and rotor tangential gas flow excitation force of the shaft seal with the anti-rotation plate through numerical simulation of steady-state rotor static eccentricity; adjusting the number of rows and installation position of the anti-rotation plate, and controlling the swirl ratio within a certain range in the shaft seal section through limited iteration; generating a coding table based on the central composite design experimental method; analyzing the rotor tangential gas flow excitation force corresponding to each anti-rotation plate structure for various anti-rotation plate structures generated based on the coding table, and obtaining the anti-rotation plate structure with the best stability. The present invention can effectively improve the dynamic characteristics of the shaft seal rotor and meet the design of the anti-rotation plate structure for rapidly and efficiently improving the multi-stage shaft seal stability enhancement and vibration suppression performance during the engineering design process.

Description

Technical Field

[0001] The present invention relates to the technical field of rotating machinery, and particularly relates to a method and system for designing an anti-rotation plate. Background Art

[0002] The rotor in a steam turbine needs to be supported on bearings and pass through the cylinder, leaving a gap between the rotor and the cylinder. During the normal operation of the steam turbine, at both ends of the high- and medium-pressure cylinders, the steam pressure inside the cylinder is greater than the external ambient pressure, and some steam leaks out through this gap, resulting in losses of working medium and energy. At both ends of the low-pressure cylinder, since the pressure inside the cylinder is negative, air will leak into the low-pressure cylinder at the gap, ultimately reducing the cycle efficiency. Therefore, an annular sealing structure is usually installed between the rotor and the cylinder in a turbomachine to control steam leakage under a high pressure difference.

[0003] Labyrinth seals are often used as shaft seals due to their advantages such as simple structure, low manufacturing cost, and easy maintenance and replacement. The shaft seal is generally divided into several sections, and there are multiple labyrinth seal steam seal rings in each section. The steam in the steam chambers between the sections is drained away or fed into the chambers through pipes. However, due to its circumferentially penetrating characteristics, the labyrinth seal is prone to insufficient rotor stability caused by the unsteady airflow excitation force generated by rotor whirling. Due to the influence of inlet pre-rotation and rotor rotation, the circumferential swirl generated inside the labyrinth seal will increase the tangential airflow excitation force in the same direction as the rotation, resulting in rotor instability. Usually, an anti-rotation plate structure is arranged at the inlet of the labyrinth seal to block or reverse-guide the circumferential airflow to improve the stability of the sealed rotor. However, the characteristics of the shaft seal having sections and some shaft seal sections being relatively long pose higher requirements for the structural design of its anti-rotation plate to enhance stability and suppress vibration.

[0004] Currently, the mainstream analysis of the anti-rotation performance of the shaft seal anti-rotation plate is carried out through a large number of experiments and numerical calculations. However, the existing technology has problems that the current anti-rotation plate design only focuses on the influence of inlet pre-rotation on the dynamic characteristics of the sealed rotor and ignores the influence of the rotor on the viscous drag of the steam flow, and there is a lack of a system for anti-rotation plate design. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the design defects of the anti-rotation plate in the prior art, and thus provide a method and system for designing an anti-rotation plate.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In a first aspect, the present invention provides a method for designing an anti-rotation plate, including the following steps:

[0008] Construct a shaft seal model based on the geometric parameters of the shaft seal, and determine the length of the anti-rotation plate and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement;

[0009] The axial variation curve of the swirl ratio of the shaft seal with the anti-rotation plate and the tangential gas flow excitation force of the rotor are obtained through the numerical simulation of the steady-state static eccentricity of the rotor.

[0010] Adjust the number of columns and the installation position of the anti-rotation plate so that the swirl ratio varying along the axis is less than the preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor.

[0011] Based on the central composite design experimental method, generate a coding table containing various combinations of the number of anti-rotation plates per column and the stagger angle.

[0012] Based on various anti-rotation plate structures generated from the coding table, by analyzing the tangential gas flow excitation force of the rotor corresponding to each anti-rotation plate structure, obtain the anti-rotation plate structure with the best stability.

[0013] The anti-rotation plate design method provided by the embodiments of the present invention constructs a shaft seal model and determines the length and installation position of the anti-rotation plate based on the model structure. Through numerical simulation, obtain the swirl ratio and the tangential gas flow excitation force of the model. Adjust the number of columns and the installation position of the anti-rotation plate to control the swirl ratio within a certain range in the shaft seal section. Generate a coding table based on the central composite design test scheme and generate anti-rotation plate structures according to the coding table to optimize the anti-rotation plate structure. Finally, by analyzing the tangential gas flow excitation force corresponding to various anti-rotation plate structures, obtain the anti-rotation plate structure with the best stability. The present invention not only considers the influence of the inlet pre-swirl on the dynamic characteristics of the sealed rotor, but also considers the influence of the rotor's viscous drag on the steam flow, thereby effectively improving the dynamic characteristics of the shaft seal rotor, and proposes an anti-rotation plate design method that can meet the requirements of quickly and efficiently improving the stability enhancement and vibration suppression performance of multi-stage shaft seals during the engineering design process.

[0014] Optionally, the installation position of the anti-rotation plate includes: between the rotor surface seal teeth, between the stator surface seal teeth and the rotor surface seal teeth, and between the rotor surface seal teeth and the stator surface seal teeth.

[0015] The present invention considers the influence of different anti-rotation plate design structures on the dynamic characteristics of the shaft seal rotor by selecting different installation positions, including different situations of the rotor surface and the stator surface, which is more conducive to finding an anti-rotation plate structure with the best stability, and the obtained analysis results are more reliable.

[0016] Optionally, the process of determining the length of the anti-rotation plate and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement includes: adding a column of anti-rotation plates with a stagger angle on the stator surface between the first pair of seal teeth near the inlet in the shaft seal to generate an initial anti-rotation plate structure, and keeping the distance between the anti-rotation plate and the rotor surface not less than the seal clearance.

[0017] The present invention designs a swirl prevention plate structure with better stability by setting the initial structure of the swirl prevention plate and installing different columns of swirl prevention plates by controlling the swirl ratio that varies axially in the shaft seal structure. The obtained design scheme can meet the requirements of quickly and efficiently improving the damping performance of multi-stage shaft seals during the engineering design process.

[0018] Optionally, the process of obtaining the curve of the swirl ratio varying axially includes: uniformly selecting cross-sections along the axis to extract the swirl ratio, where the distance between adjacent cross-sections should be less than the tooth pitch and the length of the swirl prevention plate, and the swirl ratio is the ratio of the average circumferential velocity of the gas flow to the surface velocity of the rotor.

[0019] The present invention fully considers the influence of the rotor on the viscous drag of the steam flow by obtaining the swirl ratio of the shaft seal model along the axis. Since installing the swirl prevention plate will reduce the swirl ratio, but then the gas flow will be subject to viscous drag by the rotor, resulting in a gradual increase in the swirl ratio. Therefore, cross-sections are uniformly selected along the axis and the swirl ratio is extracted, and the influence of rotor viscous drag is continuously reduced by adding swirl prevention plates subsequently, ultimately achieving the effect of enhancing stability and suppressing vibration.

[0020] Optionally, the process of adjusting the number of columns and installation positions of the swirl prevention plates so that the swirl ratio varying axially is less than a preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor includes: according to the curve of the swirl ratio varying axially after each column of swirl prevention plates, selecting the position corresponding to when the swirl ratio is greater than the preset failure swirl ratio as the end point of effective swirl prevention for each column of swirl prevention plates; based on the initial structure of the swirl prevention plate, comparing the swirl ratio varying axially after each column of swirl prevention plates with the preset failure swirl ratio, and if the swirl ratio is greater than the failure swirl ratio, increasing the number of columns of swirl prevention plates at the end point of effective swirl prevention for the corresponding swirl prevention plate until the swirl ratio of the entire shaft seal model varying axially is less than the failure swirl ratio; comparing the direction of the tangential gas flow excitation force with the rotation direction of the rotor, and if the directions are the same, reducing the failure swirl ratio and readjusting the installation position of the swirl prevention plate for numerical simulation until the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor.

[0021] The present invention optimizes the swirl prevention plate structure by repeatedly adjusting the number of columns and installation positions of the swirl prevention plates. First, according to the swirl ratio after the first column of swirl prevention plates and the preset failure swirl ratio, the end point of effective swirl prevention is selected, and a column of swirl prevention plates is added at this point, and the cycle is repeated until the swirl ratio after the first column of swirl prevention plates in the shaft seal model is less than the failure swirl ratio. Secondly, after the swirl ratio of the entire shaft seal model varying axially is less than the preset failure swirl ratio, the failure swirl ratio is reduced, and the installation position of the swirl prevention plate is adjusted according to the direction of the tangential gas flow excitation force until the direction of the tangential gas flow excitation force on the rotor is opposite to the rotation direction of the rotor. After repeated adjustment, the swirl ratio in the shaft seal section can be controlled within a certain range, thereby obtaining a swirl prevention plate structure with better performance and avoiding rotor viscous drag to a certain extent.

[0022] Optionally, the process of generating a coding table containing various combinations of the number of anti-rotation plates in each column and the stagger angle by the central composite design experimental method: Select the number of anti-rotation plates in N columns and the stagger angle as test factors, limit the value ranges of the number of anti-rotation plates in each column and the stagger angle according to the actual situation, and evenly select five values in the value range of each parameter; Generate a coding table including 2 2N +4N+1 anti-rotation plate design schemes according to the central composite design method, including 2 2N full factorial experimental schemes of 2N factors at two levels, one central point experimental scheme, and 4N axial point experimental schemes.

[0023] In the embodiment of the present invention, by adopting the central composite design method, the selected number of anti-rotation plates and the stagger angle are used as test factors and evenly divided into 5 levels to generate a two-factor five-level coding table containing various combinations of anti-rotation plate geometric parameters. This method is composed of adding extreme points and central points on the basis of the two-level factorial design, expands the design space and obtains high-order information, can provide sample data for the response surface approximation model, has the advantages of simple design, few test times, good predictability, etc., and can also ensure the reliability of the test results. In addition, on the basis of adjusting the number of anti-rotation plate columns and the installation position, further refining the adjustment of the number of anti-rotation plates and the stagger angle can control the swirl ratio in the shaft seal section within a certain range by determining the number and quantity of anti-rotation plates in the shaft seal section through limited iterations, and obtain a more optimal anti-rotation plate design structure.

[0024] Optionally, the process of obtaining the anti-rotation plate structure with the best stability by analyzing the tangential air flow excitation force of the rotor corresponding to each anti-rotation plate structure based on the coding table includes: generating various anti-rotation plate structures based on the anti-rotation plate design schemes corresponding to the coding table; performing numerical simulations of the steady-state rotor static eccentricity for each anti-rotation plate structure under the same working conditions, and calculating the corresponding index values of the tangential air flow excitation force of the rotor for various anti-rotation plate structures; normalizing the coding table, and performing quadratic polynomial fitting on the normalized coding table and the index values of the tangential air flow excitation force of each anti-rotation plate structure; analyzing according to the fitting results to obtain the anti-rotation plate structure with the best stability.

[0025] In the embodiment of the present invention, corresponding anti-rotation plate design schemes are generated through various combinations of anti-rotation plate geometric parameters included in the coding table, considering the influence degrees of different parameters and parameter combinations on the anti-rotation plate design, and the obtained test results are more reliable. In addition, in the embodiment of the present invention, quadratic polynomial fitting is performed on the results of various combinations of anti-rotation plate geometric parameters and the corresponding design schemes, and analysis is performed according to the fitting results to obtain the anti-rotation plate structure with the best stability, which can make the analysis process more intuitive and make complex data analysis work simpler.

[0026] Second aspect, an anti-rotation plate design system is provided in an embodiment of the present invention. The system includes:

[0027] A model construction module, configured to construct a shaft seal model based on shaft seal geometric parameters, and determine the length of the anti-rotation plate and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement;

[0028] A numerical simulation module, configured to obtain the axial variation curve of the swirl ratio of the shaft seal with the anti-rotation plate and the tangential gas flow excitation force of the rotor through numerical simulation of the static eccentricity of the steady-state rotor;

[0029] A structure adjustment module, configured to adjust the number of rows and the installation position of the anti-rotation plate, so that the swirl ratio varying along the axis is less than a preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor;

[0030] A coding table generation module, configured to generate a coding table including combinations of the number of anti-rotation plates in each row and the stagger angle based on the central composite design experimental method;

[0031] An optimal structure acquisition module, configured to analyze the tangential gas flow excitation force of the rotor corresponding to each anti-rotation plate structure based on multiple anti-rotation plate structures generated from the coding table, and obtain the anti-rotation plate structure with the best stability.

[0032] The anti-rotation plate design system provided in the embodiment of the present invention determines the length and installation position of the anti-rotation plate by constructing a shaft seal model and based on the model structure, obtains the swirl ratio and the tangential gas flow excitation force of the model through numerical simulation, controls the swirl ratio in the shaft seal section within a certain range by adjusting the number of rows and the installation position of the anti-rotation plate, generates a coding table based on the central composite design experimental scheme and generates an anti-rotation plate structure according to the coding table, optimizes the anti-rotation plate structure, and finally analyzes the tangential gas flow excitation force corresponding to various anti-rotation plate structures to obtain the anti-rotation plate structure with the best stability. The present invention not only considers the influence of inlet pre-swirl on the dynamic characteristics of the sealed rotor, but also considers the influence of the rotor on the viscous drag of the steam flow, thereby effectively improving the dynamic characteristics of the shaft seal rotor, and proposes an anti-rotation plate design method that can meet the requirements of quickly and efficiently improving the stability enhancement and vibration suppression performance of multi-stage shaft seals during the engineering design process.

[0033] Third aspect, a computer device is provided in an embodiment of the present invention, including: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the method described in the first aspect or any optional implementation manner of the first aspect.

[0034] Fourthly, an embodiment of the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the method described in the first aspect or any optional implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation manners of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the specific implementation manners or the description of the prior art. Obviously, the drawings in the following description are some implementation manners of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 Flow chart of a method for designing an anti-rotation plate provided by an embodiment of the present invention;

[0037] Figure 2 Structural diagram of installing an anti-rotation plate between the sealing teeth on the rotor surface and the sealing teeth on the stator surface in a method for designing an anti-rotation plate provided by an embodiment of the present invention;

[0038] Figure 3 Structural diagram of installing an anti-rotation plate between the sealing teeth on the stator surface and the sealing teeth on the rotor surface in a method for designing an anti-rotation plate provided by an embodiment of the present invention;

[0039] Figure 4 Structural diagram of installing an anti-rotation plate between the sealing teeth on the rotor surface and the sealing teeth on the rotor surface in a method for designing an anti-rotation plate provided by an embodiment of the present invention;

[0040] Figure 5 Static eccentricity diagram of the rotor in a method for designing an anti-rotation plate provided by an embodiment of the present invention;

[0041] Figure 6 Structural diagram of a system for designing an anti-rotation plate provided by an embodiment of the present invention;

[0042] Figure 7 Structural diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0044] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] An embodiment of the present invention provides an anti-rotation plate design method, as Figure 1 shown. The method specifically includes the following steps:

[0046] Step S1: Construct a shaft seal model based on the geometric parameters of the shaft seal, and determine the length of the anti-rotation plate and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement.

[0047] Specifically, in the embodiment of the present invention, the shaft seal comes from a certain high-pressure front shaft seal. In this shaft seal structure, first determine the positions where the anti-rotation plate can be installed, including between the rotor surface sealing teeth and the stator surface sealing teeth, between the stator surface sealing teeth and the rotor surface sealing teeth, and between the rotor surface sealing teeth and the rotor surface sealing teeth, as shown in Figure 2 , 3 and 4 respectively.

[0048] In practice, select the length of the anti-rotation plate, the number of anti-rotation plates, and the stagger angle of the anti-rotation plates according to the specific geometric conditions of the shaft seal section. Add a row of anti-rotation plates with a stagger angle on the stator surface between the first pair of sealing teeth near the inlet in the shaft seal, and keep the distance between the anti-rotation plate and the rotor surface not less than the sealing gap. The selection of the length of the anti-rotation plate and the relative position of the anti-rotation plate between two adjacent sealing teeth should consider the axial displacement of the rotor. At the same time, the gap between the anti-rotation plate and the rotor surface should not be less than the sealing gap. The stagger angle of the anti-rotation plate is selected with the radial direction as the axis, and the direction towards the reverse rotation direction of the rotor is taken as the positive value. The stagger angle of the anti-rotation plate set in the embodiment of the present invention is 0–60° with the radial direction as the axis and towards the reverse rotation direction. The anti-rotation plate structure obtained at this time is set as the initial anti-rotation plate structure.

[0049] Step S2: Obtain the axial variation curve of the swirl ratio of the shaft seal with the anti-rotation plate and the tangential gas flow excitation force on the rotor through the numerical simulation of the steady-state rotor static eccentricity.

[0050] Specifically, in the embodiment of the present invention, after modeling the shaft seal structure with the anti-rotation plate, use the commercial software ANSYS ICEM CFD to generate multi-block structured grids in the calculation area, and encrypt the grids at the shaft seal gap and the wall surface. Then use the commercial software ANSYS-CFX to perform steady-state numerical calculations on the fluid domain under the given boundary conditions. Finally, obtain two stability evaluation indexes under the rotor static eccentricity: the axial variation curve of the gas flow swirl ratio and the tangential gas flow excitation force.

[0051] Figure 5The schematic diagram of the rotor's static eccentricity is given. The rotor's static eccentricity means that the center point C of the rotor does not coincide with the center point O of the stator, and the whirling speed of the rotor around point O is 0 rpm. The computational grid for the seal eccentricity with the anti-rotation plate structure is obtained by solving the displacement diffusion equation using the dynamic grid technique based on the static-dynamic concentric grid. The static-dynamic eccentricity amplitude is given as 10% of the seal clearance (Cr). The specific calculation method and the parameters of the whirling model are shown in the following table:

[0052] Item Value, Attribute Solver ANSYS CFX Discretization Scheme High-Order Scheme Solution Method Steady Numerical Method, Moving Mesh Technology Turbulence Model Standard k-ε Turbulence Model, Improved Wall Function Method Working Fluid Ideal Air Vortex Frequency / Hz 0 Eccentric Amplitude / mm <![CDATA[δ = 10%C r >

[0053] The swirl ratio is defined as the ratio of the average circumferential velocity of the airflow to the surface velocity of the rotor. The specific calculation formula is as follows:

[0054] S w =·60 / (π·D·n)

[0055] In the formula: S w is the swirl ratio, V is the circumferential velocity of the airflow in the seal chamber; D is the rotor diameter; n is the rotational speed.

[0056] Step S3: Adjust the number of columns and the installation position of the anti-rotation plate so that the swirl ratio varying along the axial direction is less than the preset failure swirl ratio, and the direction of the tangential airflow excitation force is opposite to the rotational direction of the rotor.

[0057] Specifically, in the embodiment of the present invention, the swirl ratio in the shaft seal section is controlled within a certain range by selecting the failure swirl ratio. The failure swirl ratio is set as the maximum swirl ratio in the specified seal chamber after adding the anti-rotation plate, which is greater than the swirl ratio at the outlet of the anti-rotation plate and less than 1.

[0058] In the embodiment of the present invention, cross-sections are evenly selected at regular intervals along the axial direction in the shaft seal section to extract the swirl ratio. Among them, the swirl ratio is extracted by evenly selecting cross-sections along the axial direction, and the distance between adjacent cross-sections should be less than the tooth pitch and the length of the anti-rotation plate. The anti-rotation plate will reduce the swirl ratio, but then the airflow will be subject to the viscous drag of the rotor, resulting in a gradual increase in the swirl ratio.

[0059] Based on the initial structure of the anti-rotation plate, first, compare the swirl ratio after the first column of anti-rotation plates with the failure swirl ratio. When the swirl ratio rises to the failure swirl ratio, this point is taken as the end point of the effective anti-rotation of the anti-rotation plate, and a column of anti-rotation plates is added at this point to further weaken the circumferential swirl. Secondly, taking the added anti-rotation plate as the reference, repeat the comparison of the swirl ratio after this anti-rotation plate with the failure swirl ratio, and add another column of anti-rotation plates at the end point of the effective anti-rotation of the corresponding anti-rotation plate. Repeat the numerical simulation according to this operation step until the swirl ratio after the first anti-rotation plate in the shaft seal section is less than the failure swirl ratio. Finally, judge whether the failure swirl ratio is small enough according to whether the direction of the tangential excitation force is opposite to the rotation direction of the rotor. If the direction of the tangential air flow excitation force is the same as the rotation direction of the rotor, a smaller failure swirl ratio is selected to re-obtain the arrangement position of the new anti-rotation plates, and finally make the direction of the tangential air flow excitation force opposite to the rotation direction of the rotor.

[0060] Step S4: Generate a coding table containing various combinations of the number of anti-rotation plates per column and the stagger angle based on the central composite design experimental method.

[0061] Specifically, in the embodiment of the present invention, the number of anti-rotation plates in each column and the stagger angle of the anti-rotation plates are selected as analysis variables in the anti-rotation plate structure of the labyrinth seal. The value range of each parameter is determined according to the actual situation, and five levels are evenly selected within the given value range of each parameter. A 2N-factor five-level coding table is generated based on the experimental scheme of the central composite design method. Taking one column of anti-rotation plates as an example, the value range of the number of anti-rotation plates is 36 - 108, and the five levels are 36, 54, 72, 90, and 108 respectively; the value range of the stagger angle of the anti-rotation plates is 0 - 60°, and the five levels are 0, 15, 30, 45, and 60 respectively. The obtained two-factor five-level coding table is shown in the following table:

[0062] Horizontal Number Number of Anti-Swirl Plates Staggered Angle of Anti-Swirl Plates / ° 1 36 -30 2 54 -15 3 72 0 4 90 15 5 108 30

[0063] Step S5: Based on the various anti-rotation plate structures generated from the coding table, analyze the tangential air flow excitation force of the rotor corresponding to each anti-rotation plate structure to obtain the anti-rotation plate structure with the best stability.

[0064] Specifically, in the embodiment of the present invention, various anti-rotation plate structures are generated according to the experimental scheme corresponding to the generated coding table, where the coding table includes 2 2N + 4N + 1 anti-rotation plate design schemes, specifically including 2 2N two-level full-factor test schemes, where 2N parameters are combinations of levels 2 and 4; 1 central point test scheme, where all 2N parameter levels are selected as 3; and 4N axial point test schemes, where each scheme has (2N - 1) parameter selection levels of 3, and the remaining one parameter selects level 1 or 5.

[0065] Under the same working conditions, 2 2NNumerical simulation of the static eccentricity of the +4N+1 types of anti-rotation plates for 2 2N times to obtain the corresponding index values of the tangential gas flow excitation force of the rotor. Normalize the coding table, and bring the normalized coding table and the tangential gas flow excitation force obtained by numerical calculation for each combination of anti-rotation plate geometric parameters in the coding table into the commercial software Isight for quadratic polynomial fitting and post-processing to obtain the optimal parameter combination with the minimum tangential gas flow excitation force (positive in the same direction as the rotor rotation), and then obtain the anti-rotation plate structure with the best stability.

[0066] The anti-rotation plate design method provided by the embodiments of the present invention determines the anti-rotation plate length and installation position by constructing a shaft seal model and based on the model structure. The swirl ratio and tangential gas flow excitation force of the model are obtained through numerical simulation. The number of anti-rotation plate rows and installation position are adjusted to control the swirl ratio within a certain range in the shaft seal section. A coding table is generated based on the central composite design test scheme, and the anti-rotation plate structure is generated according to the coding table. The anti-rotation plate structure is optimized. Finally, by analyzing the tangential gas flow excitation forces corresponding to various anti-rotation plate structures, the anti-rotation plate structure with the best stability is obtained. The present invention not only considers the influence of the inlet pre-rotation on the dynamic characteristics of the sealed rotor, but also considers the influence of the rotor on the viscous drag of the steam flow, thereby effectively improving the dynamic characteristics of the shaft seal rotor, and proposes an anti-rotation plate design method that can meet the requirements of quickly and efficiently improving the stability enhancement and vibration suppression performance of multi-stage shaft seals during the engineering design process.

[0067] The embodiments of the present invention provide an anti-rotation plate design system, as Figure 6 shown. The system includes:

[0068] A model construction module 1 for constructing a shaft seal model based on the shaft seal geometric parameters, and determining the anti-rotation plate length and anti-rotation plate installation position based on the shaft seal model and the axial displacement. For detailed content, refer to the relevant description of step S1 in the above method embodiment, and details will not be repeated here.

[0069] A numerical simulation module 2 for obtaining the axial variation curve of the swirl ratio of the shaft seal with anti-rotation plates and the tangential gas flow excitation force of the rotor through numerical simulation of the static eccentricity of the steady-state rotor. For detailed content, refer to the relevant description of step S2 in the above method embodiment, and details will not be repeated here.

[0070] A structure adjustment module 3 for adjusting the number of rows and installation position of the anti-rotation plates so that the swirl ratio varying along the axial direction is less than the preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor. For detailed content, refer to the relevant description of step S3 in the above method embodiment, and details will not be repeated here.

[0071] The coding table generation module 4 is used to generate a coding table containing various combinations of the number of anti-rotation plates in each column and the stagger angle based on the central composite design experimental method. For the detailed content, please refer to the relevant description of step S4 in the above method embodiment, and details will not be elaborated here.

[0072] The optimal structure acquisition module 5 is used to analyze the tangential air flow excitation force of the rotor corresponding to each anti-rotation plate structure based on various anti-rotation plate structures generated by the coding table, and obtain the anti-rotation plate structure with the best stability. For the detailed content, please refer to the relevant description of step S5 in the above method embodiment, and details will not be elaborated here.

[0073] The anti-rotation plate design system provided by the embodiment of the present invention constructs a shaft seal model and determines the length and installation position of the anti-rotation plate based on the model structure, obtains the swirl ratio and tangential air flow excitation force of the model through numerical simulation, controls the swirl ratio in the shaft seal section within a certain range by adjusting the number of anti-rotation plate columns and the installation position, generates a coding table based on the central composite design test scheme and generates the anti-rotation plate structure according to the coding table, optimizes the anti-rotation plate structure, and finally analyzes the tangential air flow excitation force corresponding to various anti-rotation plate structures to obtain the anti-rotation plate structure with the best stability. The present invention not only considers the influence of inlet pre-rotation on the dynamic characteristics of the sealed rotor, but also considers the influence of the rotor on the viscous drag of the steam flow, thereby effectively improving the dynamic characteristics of the shaft seal rotor, and proposes an anti-rotation plate design method that can meet the requirements of quickly and efficiently improving the stability enhancement and vibration suppression performance of multi-stage shaft seals during the engineering design process.

[0074] Figure 7 The structural schematic diagram of the computer device in the embodiment of the present invention is shown, including: a processor 901 and a memory 902. Among them, the processor 901 and the memory 902 can be connected through a bus or other means. Figure 7 Taking the connection through the bus as an example.

[0075] The processor 901 can be a central processing unit (CPU). The processor 901 can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. chips, or combinations of the above types of chips.

[0076] The memory 902, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the above method embodiments. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions, and modules stored in the memory 902, that is, to implement the methods in the above method embodiments.

[0077] The memory 902 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created by the processor 901, etc. In addition, the memory 902 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 902 may optionally include a memory remotely disposed relative to the processor 901, and these remote memories can be connected to the processor 901 through a network. Examples of the above networks include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0078] One or more modules are stored in the memory 902 and, when executed by the processor 901, implement the methods in the above method embodiments.

[0079] For specific details of the above computer device, reference can be made to the corresponding relevant descriptions and effects in the above method embodiments for understanding, and details are not described herein again.

[0080] Those skilled in the art can understand that to implement all or part of the processes in the above method embodiments, it can be completed by instructing relevant hardware through a computer program. The implemented program can be stored in a computer-readable storage medium. When the program is executed, it may include the processes of the above method embodiments. Among them, the storage medium can be a magnetic disk, an optical disc, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memories.

[0081] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for designing an anti-rotation plate, characterized in that, Including: Construct a shaft seal model based on the shaft seal geometric parameters, and determine the anti-rotation plate length and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement. The installation position of the anti-rotation plate includes: between the rotor surface seal teeth, between the stator surface seal teeth and the rotor surface seal teeth, and between the rotor surface seal teeth and the stator surface seal teeth; Obtain the axial variation curve of the swirl ratio of the shaft seal with the anti-rotation plate and the tangential gas flow excitation force on the rotor through the numerical simulation of the steady-state rotor static eccentricity; Adjust the number of columns and the installation position of the anti-rotation plate so that the swirl ratio varying along the axis is less than the preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor; Generate a coding table containing various combinations of the number of anti-rotation plates per column and the stagger angle based on the central composite design experimental method; Based on the various anti-rotation plate structures generated from the coding table, analyze the tangential gas flow excitation force on the rotor corresponding to each anti-rotation plate structure to obtain the required anti-rotation plate structure.

2. The anti-rotation plate design method according to claim 1, wherein The process of determining the anti-rotation plate length and the installation position of the anti-rotation plate based on the shaft seal model and the axial displacement includes: adding a column of anti-rotation plates with a stagger angle on the stator surface between the first pair of seal teeth near the inlet in the shaft seal, and keeping the distance between the anti-rotation plate and the rotor surface not less than the seal clearance to generate the initial anti-rotation plate structure.

3. The anti-rotation plate design method according to claim 1, characterized in that The process of obtaining the axial variation curve of the swirl ratio includes: uniformly selecting cross-sections along the axis to extract the swirl ratio, where the distance between adjacent cross-sections should be less than the tooth pitch and the anti-rotation plate length, and the swirl ratio is the ratio of the average circumferential velocity of the gas flow to the rotor surface velocity.

4. The anti-rotation plate design method according to claim 3, characterized in that The process of adjusting the number of columns and the installation position of the anti-rotation plate so that the swirl ratio varying along the axis is less than the preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor includes: According to the axial variation curve of the swirl ratio after each column of anti-rotation plates, select the position corresponding to when the swirl ratio is greater than the preset failure swirl ratio as the end point of effective anti-rotation of each column of anti-rotation plates; Based on the initial anti-rotation plate structure, compare the axial variation of the swirl ratio after each column of anti-rotation plates with the preset failure swirl ratio. If the swirl ratio is greater than the failure swirl ratio, increase the number of columns of anti-rotation plates at the end point of effective anti-rotation of the corresponding anti-rotation plate until the swirl ratio varying along the axis of the entire shaft seal model is less than the failure swirl ratio; Compare the direction of the tangential gas flow excitation force with the rotation direction of the rotor. If the directions are the same, reduce the failure swirl ratio and readjust the anti-rotation plate position for numerical simulation until the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor.

5. The anti-rotation plate design method according to claim 1, characterized in that The process of generating a coding table containing various combinations of the number of anti-rotation plates per column and the stagger angle based on the central composite design experimental method: Select the number of anti-rotation plates per column and the stagger angle as the test factors, limit the value ranges of the number of anti-rotation plates per column and the stagger angle according to the actual situation, and uniformly select five values in the value range of each parameter; According to the central composite design method, a coding table including 2 2N + 4N + 1 anti-rotation plate design schemes is generated, including 2 2N full factorial experimental schemes of 2N factors at two levels, one central point experimental scheme, and 4N axial point experimental schemes.

6. The anti-rotation plate design method according to claim 5, characterized in that, The process of analyzing the tangential gas flow excitation force on the rotor corresponding to each anti-rotation plate structure based on the various anti-rotation plate structures generated from the coding table to obtain the required anti-rotation plate structure includes: Generate various anti-rotation plate structures based on the anti-rotation plate design schemes corresponding to the coding table; Under the same working conditions, numerical simulations of the steady-state rotor static eccentricity are carried out for each anti-rotation plate structure, and the corresponding index values of the rotor tangential gas flow excitation force of various anti-rotation plate structures are calculated; The coding table is normalized, and a quadratic polynomial fitting is performed on the normalized coding table and the index values of the rotor tangential gas flow excitation force of each anti-rotation plate structure; Analysis is carried out according to the fitting results to obtain the required anti-rotation plate structure.

7. An anti-rotation plate design system, characterized in that, Including: A model construction module, configured to construct a shaft seal model based on shaft seal geometric parameters, and determine the anti-rotation plate length and the anti-rotation plate installation position based on the shaft seal model and the axial displacement. The anti-rotation plate installation position includes: between the rotor surface sealing teeth, between the stator surface sealing teeth and the rotor surface sealing teeth, and between the rotor surface sealing teeth and the stator surface sealing teeth; A numerical simulation module, configured to obtain the axial variation curve of the swirl ratio and the rotor tangential gas flow excitation force of the shaft seal with an anti-rotation plate through numerical simulation of the steady-state rotor static eccentricity; A structure adjustment module, configured to adjust the number of columns and the installation position of the anti-rotation plate so that the swirl ratio varying along the axis is less than a preset failure swirl ratio, and the direction of the tangential gas flow excitation force is opposite to the rotation direction of the rotor; A coding table generation module, configured to generate a coding table containing various combinations of the number of anti-rotation plates in each column and the stagger angle based on the central composite design experimental method; An optimal structure acquisition module, configured to obtain the required anti-rotation plate structure by analyzing the rotor tangential gas flow excitation force corresponding to each anti-rotation plate structure based on various anti-rotation plate structures generated by the coding table.

8. An electronic device, characterized in that, Including: A memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the anti-rotation plate design method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the computer to execute the anti-rotation plate design method according to any one of claims 1-6.

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