High-reliability insert floating ring graphite seal design method

Abstract

The application discloses a high-reliability embedded floating ring graphite sealing design method, which comprises the following steps: determining design targets and parameter inputs of the floating ring sealing; establishing a floating ring sealing performance analysis model and solving the model; floating ring sealing performance evaluation, steady-state performance and dynamic performance analysis; test verification, if the test result meets the design target, outputting final parameters, and confirming structure parameters of the floating ring sealing according to the final parameters. The application can guarantee that the product has high reliability under actual working conditions, effectively reduces trial and error cost, and shortens the research and development period.

Description

Technical Field

[0001] This invention belongs to the field of floating ring sealing technology, and particularly relates to a high-reliability embedded floating ring graphite seal design method. Background Technology

[0002] The inlaid floating ring graphite seal (hereinafter referred to as the floating ring seal) is a non-contact fluid dynamic seal with simple structure, long service life, low leakage, safety and reliability, and small axial width. It is widely used in the bearing cavity of aero-engines. With the rapid development of my country's aviation industry, the operating conditions for floating ring seals have become more stringent. Currently, the rotational speed exceeds 40,000 rpm, the temperature exceeds 350 ℃, and the sealing pressure difference exceeds 0.30 MPa. The floating ring seal includes a retaining ring, a wave spring, a gasket, an inlaid ring, a graphite ring, and a base. The inlaid ring is interference-fitted onto the outer circumference of the graphite ring to form a floating ring. The radial gap between the floating ring and the base is the primary seal. The wave spring compresses the floating ring to form a secondary seal between the end face of the floating ring and the base. Its basic principle is to use the small fluid film formed between the high-speed rotating rotor and the stationary floating ring to generate fluid dynamic pressure, enabling the floating ring to achieve self-alignment and follow the rotor's radial runout. This controls fluid leakage while avoiding severe mechanical wear between the moving and stationary parts.

[0003] However, excessive interference (i.e., the assembly interference between the insert ring and the graphite ring) and improper selection of graphite insert material can lead to graphite ring cracking. Existing floating rings rely on a strong radial interference fit between the metal insert ring and the brittle graphite ring. The insertion process uses a temperature difference assembly method where the metal ring is heated and expanded before being inserted into the graphite ring. Excessive interference can lead to excessive stress, exceeding the strength limit of the graphite ring and causing cracking. Conversely, insufficient interference can cause the floating ring seal to detach at high temperatures. During insertion, the coefficient of thermal expansion of the insert ring material is often greater than that of the graphite ring. Therefore, as the temperature rises, the insertion stress gradually decreases. When the insertion stress reaches zero, detachment occurs, leading to floating ring failure. The design must ensure that the interference is within a reasonable range.

[0004] When designing floating ring seals, it is also necessary to ensure the appropriate gap size (i.e., the radial clearance between the floating ring and the runway). An excessively large gap will lead to excessive leakage, resulting in seal failure. In aero engines, excessive leakage due to a large gap will severely weaken engine efficiency and performance. Seal failure can lead to insufficient cooling of components, potentially causing overheating and damage to engine parts. The purpose of the floating ring seal in the bearing cavity is to reduce the impact of high-temperature combustion gases on the bearing. Seal failure will allow a large amount of high-temperature combustion gases to enter the main bearing cavity, causing the bearing temperature to rise rapidly and leading to rapid failure, threatening the normal operation of the engine. However, the gap cannot be too small either. When the gap is too small, direct solid friction occurs between the inner surface of the floating ring and the outer surface of the shaft. Although graphite materials have self-lubricating properties, prolonged direct contact will still cause rapid wear on the inner surface of the graphite ring. The wear can exceed the design allowable value in a short time, causing seal failure. Therefore, the gap value of the floating ring seal must be kept within a reasonable range, minimizing friction while ensuring adequate leakage.

[0005] The research and design of floating ring seals primarily focuses on steady-state performance. However, with the increasing demands for life-cycle reliability in high-end rotating machinery such as aero-engines and gas turbines, simply pursuing steady-state sealing performance is no longer sufficient to meet practical engineering needs. In actual operation, floating ring seals face frequent start-stop cycles, speed and pressure fluctuations, rotor vibration, and other dynamic conditions. The dynamic performance of the floating ring seal directly determines the long-term reliability and lifespan of the sealing assembly. Therefore, the design paradigm of floating ring seals urgently needs to shift from the traditional "steady-state performance-driven" approach to "steady-state-dynamic performance synergistic optimization," requiring in-depth research into the dynamic performance of the floating ring under dynamic conditions. Among these, stiffness and damping have become key dynamic performance parameters for improving the reliability of floating ring seals. Higher direct stiffness allows the floating ring to closely follow the rotor's motion trajectory, preventing rubbing between the two and thus improving seal life. Cross stiffness converts the rotor's rotational energy into energy that drives rotor whirl. If the cross stiffness of the floating ring seal is too high, the system is prone to half-speed whirl or oil film oscillation, leading to severe vibration of the floating ring and ultimately failure due to severe friction.

[0006] In summary, the design of floating ring seals involves several interdependent key factors: excessive interference fit can lead to graphite ring cracking, while insufficient interference fit can cause high-temperature detachment failure; excessive clearance can cause excessive leakage or even bearing overheating and burnout, while insufficient clearance can cause rubbing; simultaneously, steady-state and dynamic performance must be considered, with direct stiffness determining the floating ring's ability to follow the rotor, while cross stiffness may induce unstable vibrations such as half-speed whirl. Furthermore, material thermal matching, operating parameters, and dynamic conditions such as start-up, shutdown, and pressure fluctuations all significantly affect seal reliability. Therefore, floating ring seal design is a complex systems engineering problem involving multiple parameters, multiple objectives, and steady-state-dynamic coupling.

[0007] The lack of a systematic and comprehensive floating ring seal design method is the core pain point that restricts the efficiency and reliability of high-reliability seal research and development.

[0008] Current floating ring seal design methods rely heavily on experience for key structural parameters, lacking physical model support. Core parameters such as interference fit and clearance are often determined based on empirical values ​​or simple formulas. Verification of the design's rationality is achieved through repeated experiments to select the optimal parameters, leading to high trial-and-error costs and long design cycles. Existing methods primarily optimize steady-state leakage rate, lacking quantitative design tools for the dynamic performance of floating ring seals. In particular, the stiffness and damping characteristics of the floating ring are crucial. Direct stiffness determines the following capability, while cross-stiffness can induce half-speed whirl or oil film oscillation. Stiffness and damping play a critical role in the reliability of floating ring seals, yet they are largely neglected in the design phase, resulting in poor reliability under real dynamic conditions. In summary, current floating ring seal designs are often fragmented and open-loop, still adhering to the traditional trial-and-error stage of determining the structure based on experience and then verifying performance. This not only leads to high R&D trial-and-error costs and long cycles but also results in extremely poor adaptability and batch consistency of the final product. Summary of the Invention

[0009] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose a highly reliable embedded floating ring graphite seal design method, which ensures high reliability of the product under actual operating conditions, effectively reduces trial-and-error costs, and shortens the development cycle.

[0010] The high-reliability embedded floating ring graphite seal design method according to embodiments of the present invention includes the following steps: S1: Determine the design objectives and parameter inputs for the floating ring seal: The design objectives include the eccentricity, leakage coefficient, stiffness, damping, and life requirements of the floating ring seal under operating conditions. The parameter inputs include the operating parameters, material parameters, and structural parameters of the floating ring seal. S2: Establish and solve the floating ring sealing performance analysis model: First, establish a gap model and apply the first boundary condition to the gap model to obtain the gap size, stress distribution of the graphite ring and the insert ring, and the removal temperature under working conditions; then, establish a steady-state performance analysis model and apply the second boundary condition to the steady-state performance analysis model to obtain the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and steady-state eccentricity; then, establish a dynamic performance analysis model, decouple the dynamic performance analysis model, and integrate to obtain the direct stiffness, cross stiffness, direct damping, and cross damping. S3: Floating Ring Seal Performance Evaluation: Steady-state performance analysis is performed based on the gap size, stress distribution, and removal temperature obtained from the gap model, as well as the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and stable eccentricity obtained from the steady-state performance analysis model; dynamic performance analysis is performed based on the direct stiffness, cross stiffness, direct damping, and cross damping obtained from the dynamic performance analysis model; if the steady-state or dynamic performance does not meet the standards, structural parameter optimization is performed; S4: Experimental Verification: Manufacture test pieces of the floating ring seal according to the optimized final parameters and conduct experiments. Compare the actual test data with the simulation prediction values. If the test results meet the design objectives, output the final parameters and confirm the structural parameters of the floating ring seal based on the final parameters.

[0011] Unlike existing fragmented design methods, the high-reliability embedded floating ring graphite seal design method of this invention is the first to systematically couple and analyze the operating parameters, material parameters and structural parameters of the floating ring seal. Through numerical simulation, key performance indicators such as stress distribution, gap change, leakage rate, stiffness and damping of the floating ring are obtained, thereby determining the optimal combination of structural parameters and significantly improving the reliability of the floating ring seal under extreme operating conditions.

[0012] Compared to existing technologies, the high-reliability embedded floating ring graphite seal design method of this invention has achieved significant and multifaceted beneficial effects. Its core value is reflected in multiple dimensions such as systematic design, sealing stability, processing reliability, long-life verification, and engineering applicability. It provides a complete technical solution to address the pain points of large eccentricity, weak vibration resistance, and dispersed lifespan of floating ring seals under high-parameter operating conditions, as detailed below: (1) This invention achieves synergistic optimization of steady-state and dynamic performance, significantly improving the stability of the floating ring seal under all operating conditions. Traditional design methods only focus on steady-state performance such as steady-state leakage rate, neglecting dynamic performance such as floating ring seal stiffness, damping, and eccentricity. This invention, for the first time, incorporates dynamic performance parameters such as direct stiffness, cross stiffness, and direct damping into the design objectives, establishing a complete path from clearance analysis to steady-state performance solution, and then to dynamic stiffness and damping perturbation analysis. By controlling the dynamic performance of the floating ring seal, the risk of half-speed whirl is effectively suppressed; by increasing the direct stiffness, the floating ring's ability to follow the rotor's radial runout is enhanced, avoiding continuous rubbing.

[0013] (2) This invention significantly improves the economy and safety of floating ring seals. Floating ring seals manufactured using the design method and apparatus of this invention exhibit reduced leakage rate, enhanced anti-abrasion capability, and improved adaptability under all operating conditions, directly reducing media leakage losses and unplanned downtime caused by seal failure. For aero-engines, stable sealing performance can extend maintenance cycles and reduce total life-cycle costs. Furthermore, because this method can predict and suppress dynamic instability in advance, it effectively avoids floating ring abrasion, providing crucial protection for the safe operation of rotating machinery.

[0014] (3) It has good versatility and promotion value. The methods proposed in this invention, such as the "steady-state-dynamic performance co-optimization design process" and the "parameter input-model analysis-performance verification-experimental verification closed-loop system", are not only applicable to the floating ring graphite seal of aero-engine bearing cavity, but can also be extended to the same seal design of high-speed rotating machinery such as gas turbines, centrifugal compressors, and turbopumps. The framework of this method has clear input-output logic and quantifiable criteria, which is easy for engineers to master and apply. It is of great significance for promoting the transformation of seal design from empirical trial and error to simulation-driven design and from static design to dynamic reliability design.

[0015] (4) It can effectively reduce trial and error costs and shorten the R&D cycle.

[0016] In summary, this invention successfully solves the core problems of existing embedded floating ring graphite seals, such as large eccentricity, poor stability, weak vibration resistance, and dispersed lifespan under high temperature, high speed, and high pressure differential conditions. It achieves significant improvements in precision, reliability, and economic benefits, and has broad engineering application prospects and industrialization value.

[0017] In some embodiments, in step S1, the operating parameters of the floating ring seal are determined based on the actual operating point parameters, including the inlet temperature, high-pressure side pressure, low-pressure side pressure, and rotational speed; the materials of the insert ring, raceway, and graphite ring are initially selected, and the Poisson's ratio, coefficient of thermal expansion, and Young's modulus parameters of the corresponding materials are obtained; based on the geometric constraints of the bearing cavity and the sealing installation space, the allowable range of values ​​for each structural parameter of the floating ring seal is initially determined.

[0018] In some embodiments, in step S1, the parameter input further includes a stabilization structure for the floating ring seal, and the type and geometric characteristics of the stabilization structure are initially selected.

[0019] In some embodiments, in step S2, the gap model is specifically a two-dimensional axisymmetric model of inlay ring-graphite ring-runway; the first boundary condition includes applying the corresponding working temperature to the inlay ring, graphite ring, and runway respectively, defining the inlay ring and graphite ring as interference contact, and setting the friction coefficient according to the material pairing of graphite ring and runway. In some embodiments, in step S2, the steady-state performance analysis model is specifically the following formula for calculating fluid film pressure distribution: (1) (2) In equations (1) and (2), P For fluid membrane pressure, The density at each location of the fluid film, t For time, U The linear velocity of the rotor surface. h For fluid film thickness, For air viscosity, u p The flow velocity caused by the pressure within the gap. P 1 represents the inlet pressure of the membrane flow. P 2 represents the membrane outlet pressure. P 11 This refers to the pressure in the high-pressure side chamber. P 22 For the low-pressure side chamber pressure, The inlet pressure loss coefficient is 0.5; The second boundary conditions include: applying high-pressure side chamber pressure at the fluid membrane inlet, applying low-pressure side chamber pressure at the fluid membrane outlet, applying rotor surface linear velocity, and applying operating temperature on the fluid membrane; By solving equations (1) and (2) above, the fluid membrane pressure distribution is obtained. The flow field velocity distribution of the fluid membrane is further obtained from the obtained fluid membrane pressure distribution. The buoyancy of the fluid membrane is obtained by integrating the steady-state pressure. The leakage rate of the floating ring seal is obtained by integrating the axial velocity of the flow field. The calculation formula is as follows: (3) In equation (3), Q For leakage volume flow rate, v z The axial velocity of the fluid film. h For fluid film thickness, A The fluid membrane area is denoted as .

[0020] In some embodiments, the gap obtained under the operating conditions from the gap model is used as the input quantity for the fluid film thickness in the steady-state performance analysis model.

[0021] In some embodiments, in step S2, the dynamic performance analysis model is specifically the calculation formula for the dynamic performance parameters of the fluid membrane as follows: (4) (5) In equations (4) and (5), Kxx 、K yy For direct stiffness, K xy 、K yx For cross stiffness, C xx 、C yy For direct damping, C xy 、C yx For cross damping, P xr For the reason x Pressure disturbance component caused by minute directional displacement disturbance. P yr For the reason y The pressure disturbance component originating in the direction. θ It is an inscribed angle. l The axial length of the fluid membrane. R 1 represents the fluid film radius. P xi For the reason x The imaginary part of the pressure response caused by a small directional displacement disturbance. P yi For the reason y The imaginary part of the pressure response caused by a small directional displacement disturbance. v The frequency of the disturbance is angular frequency.

[0022] In some embodiments, in the steady-state performance analysis of step S3, the contact stress and von Mises stress distribution and magnitude of the graphite ring and the insert ring are obtained using the gap model, as well as the changes in the inner diameter of the floating ring seal, the outer diameter of the insert ring, and the outer diameter of the raceway, the initial and working gap size of the floating ring seal, and the removal temperature. At room temperature and under working conditions, the maximum values ​​of the inner diameter of the graphite ring and the contact stress and von Mises stress of the insert ring should be less than the material's compressive strength limit. If the contact stress and von Mises stress of the insert ring exceed the material's compressive strength limit, the interference fit should be appropriately reduced, and the removal temperature should be greater than the working temperature of the floating ring seal with sufficient margin. The obtained gap size is substituted into the steady-state performance analysis model, and the leakage rate obtained from the steady-state performance analysis model is solved to obtain the leakage coefficient, thereby determining whether the floating ring leakage meets the requirements; wherein, the formula for calculating the leakage coefficient is as follows: (6) In formula (6) W For the amount of quality leakage, T u This refers to the gas temperature on the high-pressure side. P 11 This refers to the pressure on the high-pressure side. Dj The outer diameter of the runway; The stable eccentricity should be controlled below 0.7; the maximum buoyancy force should be greater than the buoyancy friction resistance; if the steady-state performance of the floating ring seal is insufficient, the structural parameters need to be changed.

[0023] In some embodiments, in the dynamic performance analysis of step S3, the stiffness and damping of the floating ring seal are solved using the dynamic performance analysis model. The greater the direct stiffness, the better the following performance of the floating ring. Under the premise of meeting the leakage rate requirements, the direct stiffness is improved by reducing the working gap and / or optimizing the stabilization structure, while the cross stiffness requirement is less than 0.3. At this time, the dynamic performance of the floating ring seal is excellent and the risk of instability is low. The greater the direct damping, the stronger the impact resistance of the floating ring seal.

[0024] In some embodiments, step S4 specifically involves: manufacturing a test piece of the floating ring seal according to the optimized final parameters and installing it on the test device; operating it stably under set speed, temperature, and differential pressure conditions; the test device monitors and records leakage rate, temperature, pressure, and displacement by arranging sensors such as temperature sensors, pressure sensors, flow meters, and eddy current sensors, and periodically disassembling and inspecting the wear and dimensional changes of the graphite ring to evaluate the reliability of the seal; obtaining test results of the steady-state and dynamic performance of the floating ring seal; verifying the accuracy of the model by comparing the test results with the simulation prediction results; if the test results meet the design goals, outputting the final parameters; confirming the generation of the structural parameters of the floating ring seal based on the final parameters, thereby obtaining a high-reliability floating ring seal and completing the closed-loop verification of the design method.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] Figure 1 This is a flowchart of a high-reliability embedded floating ring graphite seal design method according to an embodiment of the present invention; Figure 2 This is a partial cross-sectional view of the floating ring seal; Figure 3 This is a schematic diagram of the experimental setup; Figure 4 yes Figure 3 Enlarged diagram of point A in the middle.

[0027] Figure Labels 1. Base; 2. Graphite ring; 3. Inlaid ring; 4. Washer; 5. Wave spring; 6. Snap ring; 7. End cover; 8. Cavity; 9. Sleeve; 10. Shaft cover; 11. Raceway; 12. Floating ring seal seat; 13. Shaft sleeve; 14. Motor main shaft; 15. Oil slinger ring. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The high-reliability embedded floating ring graphite seal design method of this invention targets a floating ring seal, i.e., an embedded floating ring graphite seal product. For example... Figure 2 As shown, the floating ring seal structure includes a base 1, a graphite ring 2, an insert ring 3, a gasket 4, a wave spring 5, and a retaining ring 6. The insert ring 3 is interference-fitted onto the outer circumference of the graphite ring 2 to form a floating ring. One side of the base 1 has an opening. Inside the base 1, from the bottom towards the opening, the floating ring, gasket 4, wave spring 5, and retaining ring 6 are sequentially arranged. The retaining ring 6 locks the floating ring, gasket 4, and wave spring 5. The floating ring seal test piece manufactured using the optimized final parameters obtained from the high-reliability insert-type floating ring graphite seal design method according to this invention needs to be tested... Figure 3 and Figure 4 The test was conducted on runway 11 of the test apparatus shown.

[0030] like Figure 1 As shown, the high-reliability embedded floating ring graphite seal design method of this invention includes the following steps: S1: Determine the design objectives and parameter inputs for the floating ring seal: The design objectives include the eccentricity, leakage coefficient, stiffness, damping, and life requirements of the floating ring seal under operating conditions. The parameter inputs include the operating parameters, material parameters, and structural parameters of the floating ring seal.

[0031] S2: Establish and solve the floating ring sealing performance analysis model: First, establish a gap model and apply the first boundary condition to the gap model to obtain the gap size, stress distribution of graphite ring 2 and inlaid ring 3 under working conditions, and removal temperature; then establish a steady-state performance analysis model and apply the second boundary condition to the steady-state performance analysis model to obtain the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and stable eccentricity; then establish a dynamic performance analysis model, decouple the dynamic performance analysis model and integrate to obtain the direct stiffness, cross stiffness, direct damping, and cross damping.

[0032] S3: Floating Ring Seal Performance Evaluation: Steady-state performance analysis is performed based on the gap size, stress distribution, and removal temperature obtained from the gap model, as well as the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and stable eccentricity obtained from the steady-state performance analysis model; dynamic performance analysis is performed based on the direct stiffness, cross stiffness, direct damping, and cross damping obtained from the dynamic performance analysis model; if the steady-state or dynamic performance does not meet the standards, structural parameter optimization is performed; S4: Experimental Verification: Test specimens of the floating ring seal are manufactured according to the optimized final parameters, and experiments are conducted. The actual test data are compared with the simulation prediction values. If the test results meet the design objectives, the final parameters are output, and the structural parameters of the floating ring seal are confirmed based on these final parameters. The high-reliability embedded floating ring graphite seal design method of this invention uses operating parameters, material parameters, and structural parameters as input conditions, and eccentricity, leakage coefficient, stiffness, damping, and life requirements as optimization objectives. By establishing a gap analysis model, a steady-state performance analysis model, and a dynamic performance analysis model, a systematic and closed-loop design process of "parameter input, model analysis, performance verification, structural optimization, and experimental verification" is formed, achieving coordinated optimization of the steady-state and dynamic performance of the floating ring seal under high-parameter operating conditions.

[0033] Unlike existing fragmented design methods, the high-reliability embedded floating ring graphite seal design method of this invention is the first to systematically couple and analyze the operating parameters, material parameters and structural parameters of the floating ring seal. Through numerical simulation, key performance indicators such as stress distribution, gap change, leakage rate, stiffness and damping of the floating ring are obtained, thereby determining the optimal combination of structural parameters and significantly improving the reliability of the floating ring seal under extreme operating conditions.

[0034] Compared to existing technologies, the high-reliability embedded floating ring graphite seal design method of this invention has achieved significant and multifaceted beneficial effects. Its core value is reflected in multiple dimensions such as systematic design, sealing stability, processing reliability, long-life verification, and engineering applicability. It provides a complete technical solution to address the pain points of large eccentricity, weak vibration resistance, and dispersed lifespan of floating ring seals under high-parameter operating conditions, as detailed below: (1) This invention achieves synergistic optimization of steady-state and dynamic performance, significantly improving the stability of the floating ring seal under all operating conditions. Traditional design methods only focus on steady-state performance such as steady-state leakage rate, neglecting dynamic performance such as floating ring seal stiffness, damping, and eccentricity. This invention, for the first time, incorporates dynamic performance parameters such as direct stiffness, cross stiffness, and direct damping into the design objectives, establishing a complete path from clearance analysis to steady-state performance solution, and then to dynamic stiffness and damping perturbation analysis. By controlling the dynamic performance of the floating ring seal, the risk of half-speed whirl is effectively suppressed; by increasing the direct stiffness, the floating ring's ability to follow the rotor's radial runout is enhanced, avoiding continuous rubbing.

[0035] (2) This invention significantly improves the economy and safety of floating ring seals. Floating ring seals manufactured using the design method and apparatus of this invention exhibit reduced leakage rate, enhanced anti-abrasion capability, and improved adaptability under all operating conditions, directly reducing media leakage losses and unplanned downtime caused by seal failure. For aero-engines, stable sealing performance can extend maintenance cycles and reduce total life-cycle costs. Furthermore, because this method can predict and suppress dynamic instability in advance, it effectively avoids floating ring abrasion, providing crucial protection for the safe operation of rotating machinery.

[0036] (3) It has good versatility and promotion value. The methods proposed in this invention, such as the "steady-state-dynamic performance co-optimization design process" and the "parameter input-model analysis-performance verification-experimental verification closed-loop system", are not only applicable to the floating ring graphite seal of aero-engine bearing cavity, but can also be extended to the same seal design of high-speed rotating machinery such as gas turbines, centrifugal compressors, and turbopumps. The framework of this method has clear input-output logic and quantifiable criteria, which is easy for engineers to master and apply. It is of great significance for promoting the transformation of seal design from empirical trial and error to simulation-driven design and from static design to dynamic reliability design.

[0037] (4) It can effectively reduce trial and error costs and shorten the R&D cycle.

[0038] In summary, this invention successfully solves the core problems of existing embedded floating ring graphite seals, such as large eccentricity, poor stability, weak vibration resistance, and dispersed lifespan under high temperature, high speed, and high pressure differential conditions. It achieves significant improvements in precision, reliability, and economic benefits, and has broad engineering application prospects and industrialization value.

[0039] In some embodiments, in step S1, the operating parameters of the floating ring seal are determined based on the actual operating point parameters (i.e., typical operating point parameters of the actual aero-engine), including inlet temperature, high-pressure side pressure, low-pressure side pressure, and rotational speed. The materials for the insert ring 3, runway 11, and graphite ring 2 are initially selected. For example, the insert ring 3 and runway 11 are made of aerospace alloy material GH4169. Using the same material for insert ring 3 and runway 11 ensures that temperature changes have a minimal impact on the sealing gap. The graphite ring 2 is made of flexible graphite material M234AO. Simultaneously, the Poisson's ratio, coefficient of thermal expansion, and Young's modulus parameters of the corresponding materials (i.e., the materials of insert ring 3, runway 11, and graphite ring 2) are obtained. Based on the geometric constraints of the bearing cavity and the sealing installation space, the allowable range of values ​​for each structural parameter of the floating ring seal is initially determined. The structural parameters of the floating ring seal include: the outer diameter, inner diameter, and width of the graphite ring 2; the outer diameter, inner diameter, and width of the insert ring 3; and the initial gap and interference fit of the floating ring. This improves the reliability of the floating ring seal design.

[0040] In some embodiments, in step S1, the parameter input further includes a stabilizing structure for the floating ring seal, and the type and geometric characteristics of the stabilizing structure are initially selected. Specifically, the stabilizing structure is disposed on the inner wall of the floating ring, that is, on the inner wall of the graphite ring 2. The stabilizing structure can be a stepped groove structure or an inner conical convergent structure; wherein the stepped groove structure specifically involves opening an annular shallow groove on the inner surface of the graphite ring 2 to reduce the contact area, form a converging wedge-shaped gap, and enhance the hydrodynamic pressure effect; the inner conical convergent structure specifically involves forming a converging conical surface on the inner surface of the floating ring to provide greater buoyancy.

[0041] This embodiment proposes a systematic design criterion for stabilization structures, filling a gap in traditional design methods. Existing design systems only address smooth inner-hole floating rings, lacking physical models and parameter optimization methods for stabilization structures such as stepped grooves and internal conical convergent structures. This embodiment establishes a modified gap analysis model and a dynamic coupling analysis model for structures with stepped grooves and internal conical convergent structures, quantitatively revealing the influence of parameters such as groove depth, groove width, and taper on leakage rate, buoyancy, direct stiffness, and cross stiffness, and providing optimization design criteria for stabilization structures. These quantitative criteria enable reliable selection and parameter matching of stabilization structures, significantly improving design efficiency and product consistency.

[0042] In some embodiments, in step S2, considering that an excessively large gap would lead to excessive leakage and seal failure of the floating ring seal, while an excessively small gap would cause direct solid friction between the inner surface of the floating ring and the outer surface of the raceway 11, in order to ensure that the size of the floating ring seal gap is within a reasonable range, the gap model specifically adopts a two-dimensional axisymmetric model of the insert ring 3-graphite ring 2-raceway 11; the first boundary conditions include: applying the corresponding operating temperature to the insert ring 3, graphite ring 2, and raceway 11 respectively, defining the insert ring 3 and graphite ring 2 as an interference contact, and setting the friction coefficient according to the material pairing of graphite ring 2 and raceway 11. In this way, the gap size, stress distribution of graphite ring 2 and insert ring 3 under the operating conditions, and the removal temperature can be obtained, which is beneficial to improving the reliability of the floating ring seal design. It should be noted that the gap obtained based on the gap model under the operating conditions will be used as the fluid film thickness input into the subsequent steady-state analysis model.

[0043] In some embodiments, in step S2, the steady-state performance analysis model specifically involves: proposing a method for correcting the inlet and outlet pressures of the fluid membrane flow in the floating ring seal using the Bernoulli equation, and obtaining the following fluid membrane pressure distribution calculation formula by simultaneously solving the Reynolds-Bernoulli equations: (1) (2) In equations (1) and (2), P For fluid membrane pressure, The density at each location of the fluid film,t For time, U The linear velocity of the rotor surface. h For fluid film thickness, For air viscosity, u p The flow velocity caused by the pressure within the gap. P 1 represents the inlet pressure of the membrane flow. P 2 represents the membrane outlet pressure. P 11 This refers to the pressure in the high-pressure side chamber. P 22 For the low-pressure side chamber pressure, The inlet pressure loss coefficient is 0.5.

[0044] The second boundary conditions include: applying pressure to the high-pressure side cavity 8 at the fluid membrane inlet, applying pressure to the low-pressure side cavity 8 at the fluid membrane outlet, applying a rotor surface linear velocity, and applying an operating temperature to the fluid membrane.

[0045] By solving equations (1) and (2) above, the fluid film pressure distribution is obtained. The flow field velocity distribution of the fluid film is further obtained from the obtained fluid film pressure distribution. The buoyancy of the fluid film is obtained by integrating the steady-state pressure. The leakage rate of the floating ring seal is obtained by integrating the axial velocity of the flow field. The calculation formula is as follows: (3) In equation (3), Q For leakage volume flow rate, v z The axial velocity of the fluid film. h For fluid film thickness, A The fluid membrane area is denoted as .

[0046] By obtaining fluid membrane pressure distribution, flow field velocity distribution, fluid membrane buoyancy, and floating ring seal leakage rate based on a steady-state analysis model, the influence of different structures and operating conditions on the steady-state characteristics of the floating ring seal can be analyzed, which helps to improve the reliability of the floating ring seal design.

[0047] In some embodiments, the clearance obtained from the clearance model under operating conditions is used as an input to the fluid film thickness in the steady-state performance analysis model. This helps to improve the reliability of the floating ring seal design.

[0048] In some embodiments, in step S2, for the dynamic study of the floating ring seal, a perturbation term is introduced into the steady-state ultra-thin gas film lubrication Reynolds equation using the perturbation method to obtain the dynamic ultra-thin gas film lubrication Reynolds equation for the seal. The dynamic Reynolds equation is obtained by adding a perturbation term to the steady-state Reynolds equation, and the various variables of the seal can be considered as composed of stable terms and perturbation terms. Substituting the decomposed physical quantities into the dynamic Reynolds equation decouples the dynamic characteristics of the floating ring seal, and integrating the dynamic pressure yields the dynamic performance analysis model, which is specifically the calculation formula for the fluid film dynamic performance parameters as follows: (4) (5) In equations (4) and (5), K xx 、K yy For direct stiffness, K xy 、K yx For cross stiffness, C xx 、C yy For direct damping, C xy 、C yx For cross damping, P xr For the reason x Pressure disturbance component caused by minute directional displacement disturbance. P yr For the reason y Pressure disturbance component caused by minute directional displacement disturbance. θ It is an inscribed angle. l The axial length of the fluid membrane. R 1 represents the fluid film radius. P xi For the reason x The imaginary part of the pressure response caused by a small directional displacement disturbance. P yi For the reason y The imaginary part of the pressure response caused by a small directional displacement disturbance. v The frequency of the disturbance is angular frequency.

[0049] In some embodiments, in the steady-state performance analysis of step S3, the contact stress and von Mises stress distribution and magnitude of the graphite ring and the insert ring are obtained using the gap model, as well as the changes in the inner diameter of the floating ring seal, the outer diameter of the insert ring, and the outer diameter of the raceway, the initial and operating gap size of the floating ring seal, and the removal temperature. At room temperature and under operating conditions, the maximum values ​​of the inner diameter of the graphite ring and the contact stress and von Mises stress of the insert ring should be less than the material's compressive strength limit. If the contact stress and von Mises stress of the insert ring exceed the material's compressive strength limit, the interference fit should be appropriately reduced, and the removal temperature should be greater than the operating temperature of the floating ring seal with sufficient margin. A gap control between 0.04 and 0.08 is more reasonable.

[0050] After obtaining the actual working clearance under various typical working conditions using the floating ring clearance model, this clearance is used as geometric input to establish a steady-state performance analysis model based on the floating ring seal. The core task of the steady-state performance analysis model is to solve for the pressure and velocity distribution of the gas film within the sealing clearance, and then obtain steady-state performance indicators such as leakage rate, buoyancy force, and critical buoyancy speed through numerical integration. The obtained clearance size is substituted into the steady-state performance analysis model, and the leakage rate obtained from the steady-state performance analysis model is solved to obtain the leakage coefficient, thereby determining whether the floating ring leakage meets the requirements; the formula for calculating the leakage coefficient is as follows: (6) In formula (6) W For the amount of quality leakage, T u This refers to the gas temperature on the high-pressure side. P 11 This refers to the pressure on the high-pressure side. D j This is the outer diameter of runway 11; The stable eccentricity should be controlled below 0.7 to ensure the stable operation of the floating ring seal; the maximum buoyancy force should be greater than the buoyancy friction resistance to ensure that the floating ring seal can float normally; if the steady-state performance of the floating ring seal is insufficient, it is necessary to change the structural parameters such as the gap size and the width of the floating ring.

[0051] In some embodiments, in the dynamic performance analysis of step S3, the stiffness and damping of the floating ring seal are solved using the dynamic performance analysis model. Direct stiffness is a key factor in ensuring that the floating ring seal rotates synchronously with the rotor; the greater the direct stiffness, the better the floating ring's following performance. Under the premise of meeting the leakage rate requirements, the direct stiffness is increased as much as possible by reducing the working clearance or optimizing the stabilization structure. Cross stiffness is the main source of rotor half-speed whirl and oil film oscillation; the cross stiffness should be as small as possible, generally less than 0.3. At this point, the floating ring seal has excellent dynamic performance and low risk of instability. Direct damping affects the floating ring seal's impact resistance; the greater the direct damping, the stronger the floating ring seal's impact resistance. Cross damping has a relatively small impact on the dynamic performance of the floating ring seal and can be ignored.

[0052] In dynamic performance analysis, stable eccentricity is also an important indicator of floating ring seal performance. Excessive eccentricity or eccentricity oscillation may cause rubbing of the floating ring seal.

[0053] The structural parameters of the floating ring seal are optimized based on the steady-state and dynamic performance analysis results. For example, if the leakage rate exceeds the standard or the direct stiffness is insufficient, the working clearance should be reduced; if the insertion stress is too high, the interference fit can be appropriately reduced; if the removal temperature is close to the high operating temperature, the interference fit can be slightly increased; if the direct stiffness is insufficient or the eccentricity is too high, the stabilization structural parameters of the floating ring seal can be changed or a new optimized groove shape can be adopted; if the critical floating speed is too high, the spring force of wave spring 5 can be reduced. Finally, the optimal floating ring seal structure is determined by comprehensively considering all factors.

[0054] In some embodiments, step S4 specifically involves: to verify the correctness and engineering applicability of the high-reliability embedded floating ring graphite seal design method of the present invention, a floating ring seal performance test needs to be conducted. The test conditions are designed to simulate the floating ring seal of an engine bearing cavity. A test piece of the floating ring seal is manufactured according to the structural parameters determined by the design method and installed on the test device. The test device is operated stably under set speed, temperature, and pressure difference conditions. The test device monitors and records leakage rate, temperature, pressure, and displacement by arranging temperature sensors, pressure sensors, flow meters, and eddy current sensors. The graphite ring 2 is periodically disassembled and inspected for wear and dimensional changes to evaluate the reliability of the seal. The test results of the steady-state and dynamic performance of the floating ring seal are obtained. The accuracy of the model is verified by comparing the test results with the simulation prediction results. If the test results meet the design objectives, the final parameters are output. The structural parameters of the floating ring seal are confirmed based on the final parameters, thereby obtaining a high-reliability floating ring seal and completing the closed-loop verification of the design method.

[0055] To further understand the high-reliability embedded floating ring graphite seal design method of the present invention, the following embodiments are listed and described in detail with reference to the accompanying drawings: Example 1: As Figures 2 to 4 As shown, this test apparatus and floating ring seal include the following components: graphite ring 2, retaining ring 6, wave spring 5, gasket 4, insert ring 3, base 1, end cap 7, cavity 8, ferrule 9, shaft cover 10, raceway 11, floating ring seal seat 12, shaft sleeve 13, motor spindle 14, and oil slinger ring 15. The specific installation and implementation steps are as follows: First, assemble the floating ring seal. The graphite ring 2 is press-fitted into the insert ring 3 using a temperature difference assembly process to form a floating ring. Then, the assembled floating ring is placed into the base 1, followed by the gasket 4 and the wave spring 5. Finally, the retaining ring 6 is used to lock and secure it, completing the overall assembly of the floating ring seal.

[0056] Next, install the main shaft and rotating components. Insert the oil slinger ring 15 and the bushing 13 into the test end of the motor main shaft 14 in sequence, fix the raceway 11 on the bushing 13, install the shaft cover 10, and lock the shaft cover 10 to the shaft head with a nut to achieve fixation.

[0057] Next, install the stationary components and the sealing test chamber. Seal the assembled floating ring (see...). Figure 4 The M mark in the figure is installed into the reserved hole of the floating ring seal seat 12. The floating ring seal seat 12 is pushed into the cavity 8 for positioning, and the ferrule 9 is installed on the outside of the cavity 8.

[0058] Finally, the system is sealed and verified. The end cap 7 is used to seal and secure the end of the cavity 8. After all hardware installation is complete, manually rotate the motor spindle 14 to check if it rotates freely and if it jams against stationary parts. Once confirmed to be correct, connect the high-speed electric spindle drive system, the adjustable temperature and pressure gas supply system, and the multi-channel data acquisition system to conduct steady-state and dynamic performance tests of the floating ring seal.

[0059] Example 2: Figure 1 This is a flowchart of a high-reliability floating ring graphite seal design method.

[0060] This method relies on the experimental setup described in Example 1 to form a closed-loop system of "parameter input - model analysis - performance verification - experimental validation". The specific design process is as follows: First, determine the design objectives and parameter inputs. Clarify the design eccentricity, leakage coefficient, stiffness, damping magnitude, and lifespan requirements of the floating ring seal under typical operating conditions. Input operating parameters, including inlet temperature, high and low pressure sides, and rotational speed; select GH4169 material for raceway 11 and insert ring 3, and M234AO material for graphite ring 2; input material parameters including Poisson's ratio, coefficient of thermal expansion, and Young's modulus; input initial values ​​for structural parameters, including the outer diameter, inner diameter, and width of graphite ring 2; the outer diameter, inner diameter, and width of insert ring 3; the initial clearance and interference fit of the floating ring; and select stabilizing structures such as stepped grooves or internal conical convergence.

[0061] Secondly, a performance analysis model for the floating ring seal is established and solved: (1) Establish the gap model: Construct a two-dimensional axisymmetric model of the inlay ring 3-graphite ring 2-runway 11, apply temperature, centrifugal force load and interference contact boundary conditions, and solve for the actual gap, von Mises stress distribution and de-insertion temperature under working conditions, ensuring that the stress is less than the material strength limit and that the de-insertion temperature has a margin.

[0062] (2) Establish a steady-state analysis model: Using the actual working clearance obtained from the solution as input, based on the simultaneous steady-state performance analysis model, solve for the pressure distribution and velocity distribution of the gas film, and calculate the steady-state leakage rate (calculate the leakage coefficient), maximum buoyancy, and steady-state eccentricity through numerical integration. The steady-state eccentricity is required to be controlled below 0.7 to ensure stable operation of the seal.

[0063] (3) Establish a dynamic analysis model: Based on the steady-state performance analysis model, a disturbance term is introduced through the perturbation method, and the dynamic characteristic parameters of the floating ring seal are obtained by decoupling and integration, namely direct stiffness, cross stiffness, direct damping and cross damping. The design requirements are to maximize the direct stiffness to ensure the following performance while meeting the leakage rate, and control the cross stiffness to reduce the risk of half-speed whirl instability.

[0064] Next, performance evaluation and structural parameter optimization are performed. If the steady-state or dynamic performance does not meet the standards, structural optimization is carried out. For example, if leakage exceeds the standard or the direct stiffness is insufficient, the working clearance is reduced; if the stress is too high, the interference fit is reduced; if the critical speed is too high, the spring force of wave spring 5 is reduced; if the stiffness is insufficient, the stabilizing structural parameters such as stepped grooves are adjusted until all design objectives are met.

[0065] Finally, experimental verification was conducted. Test specimens were manufactured according to the optimized final structural parameters and tested on the experimental apparatus of Example 1. The specimens were operated stably under set temperature, pressure, and rotational speed, with online monitoring of key data such as leakage rate, critical buoyancy speed, and radial displacement of the floating ring. The experimental data were compared with the simulation predictions. If the relative error of the leakage rate was ≤15%, the model accuracy was considered to meet the requirements, and this structural parameter was locked as the final parameter, completing the design closed loop.

[0066] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-reliability embedded floating ring graphite seal design method, characterized in that, Includes the following steps: S1: Determine the design objectives and parameter inputs for the floating ring seal: The design objectives include the eccentricity, leakage coefficient, stiffness, damping, and life requirements of the floating ring seal under operating conditions. The parameter inputs include the operating parameters, material parameters, and structural parameters of the floating ring seal. S2: Establish and solve the floating ring sealing performance analysis model: First, establish a gap model and apply the first boundary condition to the gap model to obtain the gap size, stress distribution of graphite ring and inlay ring and the removal temperature under working conditions. A steady-state performance analysis model is then established, and a second boundary condition is applied to the steady-state performance analysis model to obtain the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and steady-state eccentricity. Then, a dynamic performance analysis model is established, and the dynamic performance analysis model is decoupled and integrated to obtain the direct stiffness, cross stiffness, direct damping, and cross damping. S3: Floating Ring Seal Performance Evaluation: Steady-state performance analysis is performed based on the gap size, stress distribution, and removal temperature obtained from the gap model, as well as the fluid film pressure distribution, flow field velocity distribution, steady-state leakage rate, maximum buoyancy, and stable eccentricity obtained from the steady-state performance analysis model; dynamic performance analysis is performed based on the direct stiffness, cross stiffness, direct damping, and cross damping obtained from the dynamic performance analysis model; if the steady-state or dynamic performance does not meet the standards, structural parameter optimization is performed; S4: Experimental Verification: Manufacture test pieces of the floating ring seal according to the optimized final parameters and conduct experiments. Compare the actual test data with the simulation prediction values. If the test results meet the design objectives, output the final parameters and confirm the structural parameters of the floating ring seal based on the final parameters.

2. The high-reliability embedded floating ring graphite seal design method according to claim 1, characterized in that, In step S1, the operating parameters of the floating ring seal are determined based on the actual operating point parameters, including the inlet temperature, high-pressure side pressure, low-pressure side pressure, and rotational speed; the materials of the insert ring, raceway, and graphite ring are initially selected, and the Poisson's ratio, coefficient of thermal expansion, and Young's modulus parameters of the corresponding materials are obtained; based on the geometric constraints of the bearing cavity and the sealing installation space, the allowable range of values ​​for each structural parameter of the floating ring seal is initially determined.

3. The high-reliability embedded floating ring graphite seal design method according to claim 2, characterized in that, In step S1, the parameter input also includes the stabilization structure of the floating ring seal, and the type and geometric characteristics of the stabilization structure are initially selected.

4. The high-reliability embedded floating ring graphite seal design method according to claim 2, characterized in that, In step S2, the gap model is specifically a two-dimensional axisymmetric model of inlay ring-graphite ring-runway; the first boundary condition includes applying the corresponding working temperature to the inlay ring, graphite ring, and runway respectively, defining the inlay ring and graphite ring as interference contact, and setting the friction coefficient according to the material pairing of graphite ring and runway.

5. The high-reliability embedded floating ring graphite seal design method according to claim 4, characterized in that, In step S2, the steady-state performance analysis model is specifically the following formula for calculating fluid film pressure distribution: （1） (2) In equations (1) and (2), P For fluid membrane pressure, The density at each location of the fluid film, t For time, U The linear velocity of the rotor surface. h For fluid film thickness, For air viscosity, u p The flow velocity caused by the pressure within the gap. P 1 represents the inlet pressure of the membrane flow. P 2 represents the membrane outlet pressure. P 11 This refers to the pressure in the high-pressure side chamber. P 22 For the low-pressure side chamber pressure, The inlet pressure loss coefficient is 0.5; The second boundary conditions include: applying high-pressure side chamber pressure at the fluid membrane inlet, applying low-pressure side chamber pressure at the fluid membrane outlet, applying rotor surface linear velocity, and applying operating temperature on the fluid membrane; By solving equations (1) and (2) above, the fluid film pressure distribution is obtained. The flow field velocity distribution of the fluid film is further obtained from the obtained fluid film pressure distribution. The buoyancy of the fluid film is obtained by integrating the steady-state pressure. The leakage rate of the floating ring seal is obtained by integrating the axial velocity of the flow field. The calculation formula is as follows: （3） In equation (3), Q For leakage volume flow rate, v z The axial velocity of the fluid film. h For fluid film thickness, A This represents the fluid membrane area.

6. The high-reliability embedded floating ring graphite seal design method according to claim 5, characterized in that, The gap obtained under the working conditions from the gap model is used as the input quantity for the fluid film thickness in the steady-state performance analysis model.

7. The high-reliability embedded floating ring graphite seal design method according to claim 6, characterized in that, In step S2, the dynamic performance analysis model is specifically defined by the following formulas for calculating the dynamic performance parameters of the fluid membrane: （4） （5） In equations (4) and (5), K xx 、K yy For direct stiffness, K xy 、K yx For cross stiffness, C xx 、C yy For direct damping, C xy 、C yx For cross damping, P xr For the reason x Pressure disturbance component caused by minute directional displacement disturbance. P yr For the reason y Pressure disturbance component caused by minute directional displacement disturbance. θ It is an inscribed angle. l The axial length of the fluid film. R 1 represents the fluid film radius. P xi For the reason x The imaginary part of the pressure response caused by a small directional displacement disturbance. P yi For the reason y The imaginary part of the pressure response caused by a small directional displacement disturbance. v The frequency of the disturbance is angular frequency.

8. The high-reliability embedded floating ring graphite seal design method according to claim 7, characterized in that, In the steady-state performance analysis in step S3, the contact stress and von Mises stress distribution and magnitude of the graphite ring and the insert ring are obtained using the gap model, as well as the changes in the inner diameter of the floating ring seal, the outer diameter of the insert ring, and the outer diameter of the raceway, the initial and working gap size of the floating ring seal, and the removal temperature. The maximum values ​​of the inner diameter of the graphite ring and the contact stress and von Mises stress of the insert ring at room temperature and under working conditions should be less than the material's compressive strength limit. If the contact stress and von Mises stress of the insert ring exceed the material's compressive strength limit, the interference fit should be appropriately reduced, and the removal temperature should be greater than the working temperature of the floating ring seal with sufficient margin. The obtained gap size is substituted into the steady-state performance analysis model, and the leakage rate obtained from the steady-state performance analysis model is solved to obtain the leakage coefficient, thereby determining whether the floating ring leakage meets the requirements; wherein, the formula for calculating the leakage coefficient is as follows: （6） In formula (6) W For the amount of quality leakage, T u The high-pressure side gas temperature, P 11 This refers to the pressure on the high-pressure side. D j The outer diameter of the runway; The stable eccentricity should be controlled below 0.7; the maximum buoyancy force should be greater than the buoyancy friction resistance; if the steady-state performance of the floating ring seal is insufficient, the structural parameters need to be changed.

9. The high-reliability embedded floating ring graphite seal design method according to claim 8, characterized in that, In the dynamic performance analysis of step S3, the stiffness and damping of the floating ring seal are solved using the dynamic performance analysis model. The greater the direct stiffness, the better the following performance of the floating ring. Under the premise of meeting the leakage rate requirements, the direct stiffness can be increased by reducing the working gap or optimizing the stabilization structure. At this time, the dynamic performance of the floating ring seal is excellent and the risk of instability is low. The greater the direct damping, the stronger the impact resistance of the floating ring seal.

10. The high-reliability embedded floating ring graphite seal design method according to claim 9, characterized in that, Step S4 specifically involves: manufacturing a test piece of the floating ring seal according to the optimized final parameters and installing it on the test device; operating it stably under the set speed, temperature, and differential pressure conditions; the test device monitors and records leakage rate, temperature, pressure, and displacement by arranging sensors such as temperature sensors, pressure sensors, flow meters, and eddy current sensors, and periodically disassembling and inspecting the wear and dimensional changes of the graphite ring to evaluate the reliability of the seal; obtaining the test results of the steady-state and dynamic performance of the floating ring seal; verifying the accuracy of the model by comparing the test results with the simulation prediction results; if the test results meet the design objectives, outputting the final parameters; confirming the structural parameters of the floating ring seal based on the final parameters, thereby obtaining a high-reliability floating ring seal and completing the closed-loop verification of the design method.

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