Checking and judging method, system and device for wedge-shaped pressing ring and O-shaped ring two-way sealing structure of graphite heat exchanger

Abstract

The invention provides a checking and judging method, system and device for a wedge-shaped pressing ring and O-shaped ring two-way sealing structure of a graphite heat exchanger, and belongs to the technical field of chemical equipment sealing. The method comprises the following steps: determining structural parameters required for checking and judging the sealing performance, and determining the optimal inclination angle of the inclined surfaces of the wedge-shaped grooves of the upper and lower pressure rings by adopting an inclination angle calculation model with temperature and pressure compensation; checking and judging the bidirectional sealing structure, wherein the checking and judging comprise bidirectional sealing force checking, compression ratio collaborative checking and graphite contact stress safety judgment; and if any check or safety judgment of the check of the two-way sealing structure is not met, adjusting parameters according to the sequence of adjusting the optimal inclination angle alpha, replacing the diameter of the O-shaped ring and modifying the reference distance, and outputting a recommended parameter set. According to the method, the sealing performance of the wedge-shaped pressing ring O-shaped ring bidirectional sealing structure can be accurately calculated and judged, the checking calculation precision and safety of the sealing structure are improved, and the sealing effect and operation reliability of equipment are effectively guaranteed.

Description

Technical Field

[0001] The invention relates to a method, system and device for checking and determining a bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger, and belongs to the technical field of chemical equipment sealing. Background Art

[0002] In the structural design of graphite heat exchangers, a wedge-shaped pressure ring + O-ring sealing structure is often used between the shell-side metal components at the sliding end of the heat exchanger and the tube-side graphite head. During design, it is usually simplified to a one-way sealing structure, and the sealing performance is checked according to the flat gasket sealing structure. This simplified model does not consider key factors such as the synergistic constraint of the compression rate, and is far from the actual sealing state and principle. For graphite components, there is a lack of a limit standard for the sealing contact stress threshold. During the construction process, microcracks or even cracks and damage often occur in the graphite components due to excessive contact stress. The selection of the O-ring compression rate in the project depends entirely on experience, resulting in large design deviations and small assembly tolerances. The above technical defects seriously restrict the reliability of this sealing structure, and it is urgent to develop a precise verification method for multi-parameter coupling to achieve accurate design. Summary of the Invention

[0003] The purpose of the present invention is to provide a calibration and judgment method, system and device for the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger, which solves the problems of unreasonable calculation models, limitations, large empirical design deviations and lack of calibration and limitation standards for the sealing contact stress of graphite components in traditional design methods.

[0004] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0005] In a first aspect, a method for verifying and determining a bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger is provided, comprising the following steps:

[0006] Determine the structural parameters required for sealing performance verification and use an inclination calculation model with temperature and pressure compensation to determine the optimal inclination angle of the wedge-shaped groove surface of the upper and lower pressure rings;

[0007] Conduct bidirectional sealing structure verification and assessment, including bidirectional sealing force verification, compression ratio coordination verification, and graphite contact stress safety assessment, specifically including:

[0008] The bidirectional sealing force verification calculates the radial sealing force and the effective axial sealing force by decomposing the axial preload force, and judges whether the radial sealing force and the effective axial sealing force meet the verification conditions according to the dynamic safety factor and the preload force of the pressure ring bolt.

[0009] The compression rate collaborative verification calculates the radial compression rate and the axial compression rate of the O-ring, and verifies and determines whether the radial compression rate and the axial compression rate meet the specified requirements according to the set threshold range;

[0010] The graphite contact stress safety determination is performed by calculating the maximum contact stress between the O-ring and the graphite head and taking into account the anisotropy correction coefficient to limit the maximum contact stress within the allowable range;

[0011] When any of the verification or safety judgments in the bidirectional sealing structure is not satisfied, the parameters are adjusted in the order of adjusting the inclination angle of the wedge-shaped pressure ring groove, replacing the diameter of the free section of the O-ring, and adjusting the distance from the axial installation reference surface to the center of the O-ring, and a parameter set that meets the verification judgment of the bidirectional sealing structure is output.

[0012] Preferably, the structural parameters required for sealing performance verification include: outer diameter of the graphite head, inclination angle of the wedge-shaped pressure ring groove, shell-side design pressure of the graphite heat exchanger, shell-side design temperature of the graphite heat exchanger, and bending strength of graphite, wherein the inclination angle of the wedge-shaped pressure ring groove is in the range of [15°, 25°].

[0013] The tilt angle calculation model with temperature and pressure compensation is a temperature-pressure coupling constraint equation, and the specific formula is as follows:

[0014] α=20°+0.08(T-80℃)-0.1P,(T∈[50,200]℃,P∈[0.1,2.0]MPa),

[0015] Among them, α represents the inclination angle of the wedge-shaped pressure ring groove, T represents the shell-side design temperature of the graphite heat exchanger, and P represents the shell-side design pressure of the graphite heat exchanger.

[0016] Preferably, the calculation formula of radial sealing force and effective axial sealing force is:

[0017]

[0018] Among them, F r Indicates radial sealing force, F a Indicates the axial preload of the pressure ring, F' a represents the effective axial sealing force, μ1 is the measured friction coefficient between the O-ring and the graphite head, and μ2 is the friction coefficient between the O-ring and the metal pressure ring;

[0019] The calibration conditions are as follows:

[0020]

[0021] Where: D g is the outer diameter of the graphite head, S f is the dynamic safety factor, is the pre-tightening force of the compression ring bolt.

[0022] Preferably, the friction coefficient μ2 is corrected using the following method:

[0023] μ2(T)=μ 2,20℃ ·[1+0.002(T-293)](T∈[253,473]K)

[0024] Among them, μ 2,20℃ Expressed as the friction coefficient between the O-ring and the metal pressure ring at 20°C.

[0025] Preferably, the calculation formula and verification formula of the radial compression rate and axial compression rate of the O-ring are as follows:

[0026]

[0027] Among them, δ r Indicates the radial compression rate of the O-ring, Δ r Indicates the radial compression of the O-ring after installation, δ a It represents the axial compression rate of the O-ring, d0 represents the cross-sectional diameter of the O-ring in the free state, and h represents the distance from the axial mounting reference surface to the center of the O-ring.

[0028] Preferably, the maximum contact stress between the O-ring and the graphite head is calculated as follows:

[0029]

[0030] Among them, L c represents the equivalent effective contact half-width, σ max Indicates the maximum contact stress, K anis represents the anisotropy correction coefficient, σ b Indicates the bending strength of graphite, E g is the elastic modulus of graphite material at design temperature, E o is the elastic modulus of the O-ring material at the design temperature, ν g is the Poisson's ratio of graphite material, ν o is the Poisson's ratio of the O-ring material, E g,radial is the radial elastic modulus of graphite material, E g,axial is the axial elastic modulus of graphite material.

[0031] Preferably, the safety judgment condition of the maximum contact stress is based on the Weibull failure probability model, and the formula is as follows:

[0032] P f =1-exp[-(σ max / σ b ) m ]

[0033] Among them, P f represents the failure probability, m is the Weibull modulus, and its value range is [10,15];

[0034] When σ max ≤0.6σ b When the failure probability is less than 0.02%, the safety judgment is passed.

[0035] Preferably, the inclination angle of the groove of the wedge-shaped pressure ring in the recommended parameter set is subjected to multi-objective optimization based on the sealing force ratio, and the specific expression is:

[0036]

[0037] The adjustment priority rules for the O-ring radial compression rate and the O-ring axial compression rate in the recommended parameter set are as follows:

[0038] When δ r When the standard value is exceeded, adjust Δ r , adjust the step size Δ step satisfy:

[0039] Δ step =0.1·min(|Δ r -0.11D g |,|Δ r -0.15D g |),

[0040] When δ a When the standard value is exceeded, h should be adjusted first, and the distance modification Δh from the axial installation reference surface to the center of the O-ring should meet the following requirements:

[0041] Δh=0.5·(δ a -18%)·d0,

[0042] When Δ r Or if h is adjusted to reach the design limit but still cannot meet the compression ratio requirement or the compression ratio ratio still exceeds the limit, d0 is adjusted.

[0043] In a second aspect, a calibration and determination system for a bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger is provided, comprising:

[0044] Parameter input module: verify the integrity of medium parameters, material properties, and geometric dimensions;

[0045] Core calculation engine: executes the bidirectional sealing force verification, compression rate collaborative verification and graphite contact stress safety judgment of the method;

[0046] Dynamic Optimizer: adjusts parameters in the order of adjusting the optimal tilt angle, changing the O-ring diameter, and modifying the reference distance;

[0047] Result output module: outputs the recommended parameter set.

[0048] In a third aspect, a calibration and determination device for a bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger is provided, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute the calibration and determination method for the bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger when running the program instructions.

[0049] The advantages of the present invention are:

[0050] This invention addresses the challenges of traditional design methods, including irrational calculation models, limitations, large empirical design deviations, and a lack of standards for verifying contact stress in graphite component seals. This approach bridges the technical gap between theoretical accuracy and engineering applicability. By considering the combined effects of internal pressure and temperature loads, this pioneering temperature-pressure coupled inclination angle calculation model comprehensively accounts for initial sealing stress and the thermal expansion differential between metal and graphite. Compared to empirical designs, this method improves verification accuracy to ±5%.

[0051] The present invention establishes a bidirectional sealing verification mechanical model through the mechanical decomposition of the wedge groove inclination angle, and realizes the quantitative verification of the bidirectional sealing effect. A multi-physics field coupling algorithm is established, and the Kanis coefficient is introduced to correct the influence of the elastic modulus difference of graphite in different directions on the contact stress. The stress calculation error is reduced from ±25% to ±8%. Based on the improved Hertz contact theory, L c The calculation formula can accurately predict the contact stress distribution and avoid stress concentration in the graphite head, resulting in micro cracks or fracture failure.

[0052] The present invention can be directly used to verify the sealing performance of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger. It adopts a dual-parameter dynamic matching of the compression rate collaborative constraint mechanism and defines the collaborative constraints of the axial compression rate and the radial compression rate to avoid the risk of leakage caused by over-compression or under-compression of the O-ring. If the verification fails, it can be optimized by adjusting parameters such as the wedge-shaped pressure ring groove angle or the O-ring diameter until the requirements are met. This design method based on precise calculation helps to improve the reliability of the seal.

[0053] The present invention has the function of risk warning, realizes the precise control and automatic verification of leakage risk, monitors parameter deviation in real time, introduces Weibull failure probability model, sets σ max ≤0.6σ b When the failure probability P f <0.02%. Through the coordinated control of the compression rate, the service life of the O-ring can be extended, the frequent replacement of the O-ring due to excessive compression can be avoided, and the safety of the long-term operation of the sealing structure can be ensured.

[0054] On the premise of breaking through technical bottlenecks, the present invention introduces an integrated NSGA-II multi-objective optimization algorithm, develops an automated verification calculation system through parametric design tools, and automatically generates a three-dimensional design space solution set that meets the sealing performance requirements after iterative calculation for engineering designers to compare and select, greatly improving the design calculation efficiency.

[0055] The present invention is compatible with various O-ring sealing materials such as FFKM and PTFE, is suitable for extreme working conditions such as alternating high and low temperatures, can be seamlessly connected with the existing engineering design standard system, has broad engineering application value, and can be further expanded to pharmaceutical, food, energy, nuclear power and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0057] Figure 1 Schematic diagram of the process of the present invention.

[0058] Figure 2 This is a schematic diagram of the wedge-shaped pressure ring O-ring sealing structure of the present invention.

[0059] Figure 3 This is a partially enlarged view of the initial state of the wedge-shaped pressure ring O-ring sealing structure of the present invention.

[0060] Figure 4 It is a schematic diagram of the mechanical model of the wedge-shaped pressure ring O-ring sealing structure in the pre-tightened state of the present invention.

[0061] In the figure: 1. Graphite head; 2. Fastening nut; 3. Stud; 4. Upper pressure ring; 5. Lower pressure ring; 6. Shell and cylinder; 7. O-ring; 8. Graphite block hole; 9. Spring. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0063] Example 1

[0064] A verification and assessment method for bidirectional seals of wedge-shaped O-rings in graphite heat exchangers is suitable for designing and verifying seal reliability in high- and low-temperature cycling conditions. This method addresses technical challenges inherent in traditional designs, such as large empirical biases and a lack of systematic assessment criteria, through quantitative verification criteria, multi-physics coupling calculations, and correction for graphite material anisotropy.

[0065] Specifically, the following steps are included:

[0066] S1: Structural parameter definition and input verification: Determine the structural parameters required for sealing performance verification and use an inclination angle calculation model with temperature and pressure compensation to determine the optimal inclination angle of the wedge-shaped groove surface of the upper and lower pressure rings.

[0067] S2: Check and determine the bidirectional sealing structure, including bidirectional sealing force check, compression ratio coordinated check and graphite contact stress safety determination, specifically including:

[0068] S201: Bidirectional sealing force verification: The bidirectional sealing force verification calculates the radial sealing force and the effective axial sealing force by decomposing the axial preload force, and determines whether the radial sealing force and the effective axial sealing force meet the verification conditions based on the dynamic safety factor and the preload force of the compression ring bolt.

[0069] S202: Compression rate collaborative verification: The compression rate collaborative verification calculates the radial compression rate and the axial compression rate of the O-ring, and verifies and determines whether the radial compression rate and the axial compression rate meet the specified requirements based on a set threshold range.

[0070] S203: Graphite contact stress safety assessment: The graphite contact stress safety assessment is performed by calculating the maximum contact stress between the O-ring and the graphite head and taking into account the anisotropy correction coefficient to limit the maximum contact stress within an allowable range.

[0071] S3: Dynamic optimization and result output: When any of the verification or safety judgments of the bidirectional sealing structure is not satisfied, the parameters are adjusted in the order of adjusting the inclination angle of the wedge-shaped pressure ring groove, changing the diameter of the free state section of the O-ring, and adjusting the reference distance, and the recommended parameter set is output.

[0072] As a refinement of the above embodiment, in step S1, the structural parameters required for sealing performance verification are first defined, and an inclination angle calculation model that takes into account temperature and pressure compensation is used to determine the optimal inclination angle of the wedge-shaped groove bevel of the upper and lower pressure rings. When key parameters are missing, the verification is terminated, and the key parameters include the shell side design pressure, design temperature and graphite bending strength of the graphite heat exchanger;

[0073] like Figure 2 and Figure 3As shown, the graphite heat exchanger wedge-shaped pressure ring O-ring bidirectional sealing structure, its main structure includes a graphite head 1, a fastening nut 2, a stud 3, an upper pressure ring 4, a lower pressure ring 5 and an O-ring 7; the lower end of the lower pressure ring 5 is connected to the shell cylinder 6 by welding to form a whole; the lower surface of the upper pressure ring 4 and the upper surface of the lower pressure ring 5 are provided with wedge-shaped grooves of the same size and symmetrical structure near the corners of the graphite head 1, and the inclination angle of the wedge-shaped groove is α; the cross-section shape of the O-ring 7 in the initial state is circular, and its material is usually synthetic rubber with filler, and the Shore hardness is not higher than 75; the material of the graphite head 1 is impregnated graphite, and its bending strength after impregnation σ b Not less than 30MPa; the lower surface of the lower pressure ring 5, the cylindrical surface of the graphite head 1 and the inner surface of the shell cylinder 6 bear the shell internal pressure.

[0074] Specifically, they include:

[0075] S101: Define the sealing structure:

[0076] According to the process operation parameter requirements of the graphite heat exchanger, define the outer diameter D of the graphite head g , the inclination angle α of the wedge-shaped groove of the pressure ring is limited to 15°≤α≤25°.

[0077] S102: Define design parameters:

[0078] Define the shell side design pressure P (MPa), design temperature T (℃), graphite bending strength σ of graphite heat exchanger b (MPa), limit σ b ≥30MPa, and verify the integrity of the design parameters.

[0079] S103: Correct the inclination angle α according to the temperature-pressure coupling constraint equation. The correction calculation formula is:

[0080] α=20°+0.08(T-80℃)-0.1P, (T∈[50,200]℃, P∈[0.1,2.0]MPa).

[0081] Step S1 uses the temperature-pressure coupling constraint equation to correct the inclination angle α. This is primarily due to the fact that as temperature rises, the thermal expansion difference between the graphite and metal pressure rings increases, requiring an increase in inclination angle α to enhance radial sealing force and compensate for the loss of preload due to thermal deformation. On the other hand, as pressure increases, the separating force exerted by the medium on the sealing surface increases, requiring a decrease in inclination angle α to increase the proportion of radial sealing force and offset the influence of medium pressure. The coefficient of 0.08 is derived through experimental calibration of the material's thermal expansion coefficient, while the coefficient of 0.1 is calculated based on an optimized force balance model for the sealing surface. These values ​​balance theoretical rigor with engineering practicality.

[0082] The temperature-pressure coupling constraint equation can automatically correct the impact of extreme temperature and pressure fluctuations on sealing performance, accurately compensate for material thermal expansion and medium pressure fluctuations, improve the adaptability of the sealing structure to dynamic working conditions, and avoid the over-conservative or unsafe traditional static design methods.

[0083] As a refinement of the above embodiment, the bidirectional sealing force verification in step S201 specifically includes:

[0084] S2011: Establish axial preload F a Decompose the model and calculate the radial sealing force F r and effective axial sealing force F' a , and its calculation formula is:

[0085]

[0086] Where:

[0087] μ1 is the measured friction coefficient between the O-ring and the graphite head, dimensionless;

[0088] μ2 is the friction coefficient between the O-ring and the metal pressure ring, which is dimensionless.

[0089] The effective axial sealing force F' a In the calculation formula, the friction coefficient μ2 can be corrected by the following method, and the correction formula is:

[0090] μ2(T)=μ 2,20℃ ·[1+0.002(T-293)](T∈[253,473]K),

[0091] Where:

[0092] μ 2,20℃ is the friction coefficient between the O-ring and the metal pressure ring at 20°C, dimensionless;

[0093] T is the design temperature, unit is K.

[0094] S2012: Perform bidirectional sealing force verification, and the verification conditions are:

[0095]

[0096] Where:

[0097] S f is the dynamic safety factor, dimensionless;

[0098] is the preload force of the compression ring bolt, unit is N.

[0099] In the bidirectional sealing force verification conditions, the dynamic safety factor S fThe main consideration is the combined effects of material performance fluctuations, manufacturing errors, and long-term creep. If F r If it is insufficient, the medium pressure will push the sealing interface open, causing leakage; Based on the safety threshold of the bolt material yield strength, ensure the durability of the flange face seal, During the installation process, digital installation tools such as torque wrenches can be used for measurement.

[0100] The bidirectional sealing verification system described in step S201 covers the entire sealing interface. Through mechanical model innovation and dynamic parameter optimization, it solves the design defects of traditional design calculations that only focus on a single axial or radial sealing path, have large empirical design deviations, and have poor adaptability to dynamic working conditions, and provides a systematic technical solution.

[0101] As a refinement of the above embodiment, step S202 specifically includes:

[0102] Calculate the radial compression rate δ of the O-ring r and axial compression rate δ a , and verify the double parameter constraints, the calculation formula is:

[0103]

[0104] Where:

[0105] Δ r The radial compression of the O-ring after installation, unit: mm;

[0106] d0 is the diameter of the O-ring cross section in the free state, in mm;

[0107] h is the distance from the axial mounting reference surface to the center of the O-ring, in mm.

[0108] The dual parameter constraint verification condition described in step S202 is given by r and δ a The main purpose is to extend the service life of the material (graphite / O-ring) under the premise of ensuring sealing. r If the contact stress is too large, the contact stress may exceed the limit, and the graphite material may be at risk of overload and burst. r ∈[22%,30%], so that the contact stress between the O-ring and the graphite head is distributed as evenly as possible, which can effectively reduce the breakage rate of the graphite head; too high δ a It will accelerate the stress relaxation of the O-ring by limiting δ a ≤18%, avoiding permanent deformation of the O-ring caused by over-compression, thereby increasing the service life of the O-ring.

[0109] The dual parameter constraint verification condition described in step S202 controls δ r and δa The physical meaning of the ratio is to ensure the balance between radial sealing force and axial pressing force. r and δ a , to avoid local failure caused by overload of a single compression ratio, combined with the temperature-pressure coupling constraint equation, the compression ratio combination is adjusted to adapt to extreme working conditions. In addition, in traditional design calculations, δ r and δ a Independent control can easily increase the risk of sealing failure due to tolerance superposition. Dual parameter ratio constraints can reduce the impact of tolerance by 60%.

[0110] As a refinement of the above embodiment, step S203 specifically includes:

[0111] Introducing anisotropy correction factor K anis and equivalent effective contact half-width L c , calculate the maximum contact stress σ max , and make safety judgment on it, σ max The calculation formula of related intermediate variables is:

[0112]

[0113] Where:

[0114] E g is the elastic modulus of graphite material at the design temperature, unit: MPa;

[0115] E o It is the elastic modulus of the O-ring material at the design temperature, in MPa;

[0116] ν g is the Poisson's ratio of graphite material, dimensionless;

[0117] ν o is the Poisson's ratio of the O-ring material, dimensionless;

[0118] E g,radial is the radial elastic modulus of graphite material, unit: MPa;

[0119] E g,axial It is the axial elastic modulus of graphite material, unit is MPa.

[0120] The anisotropy correction coefficient K introduced in the safety judgment condition in step S203 anis Its engineering significance is to quantify anisotropy and avoid the risk of ignoring anisotropy in traditional models. By correcting the difference in elastic modulus of graphite in different directions (impregnated graphite E ⊥ / E || ≈1.8), ensuring that the stress calculation can cover the most unfavorable direction and achieve accurate calculation of contact stress. K anisThe coefficient 0.15 in the calculation formula is based on finite element simulation fitting and reflects the sensitivity of anisotropy to contact stress.

[0121] The equivalent effective contact half width L introduced in the safety judgment condition in step S203 c Based on the improved Hertz contact theory, its expression essentially reflects the balanced relationship between the compression deformation energy of the O-ring and the elastic deformation energy of graphite. It associates the geometric parameters of the sealing structure with the material parameters to achieve global optimization of the design variables. By quantifying the contact width, it truly reflects the contact area after compression deformation, avoiding the underestimation of the stress peak by traditional calculation models and the overly conservative design caused by blindly increasing the safety factor to cover the calculation error in empirical design.

[0122] Step S203 max The safety judgment conditions are derived based on the Weibull failure probability model:

[0123] P f =1-exp[-(σ max / σ b ) m ]

[0124] Among them, P f It represents the failure probability, m is the Weibull modulus, and its value range is [10,15], which reflects the uniformity of material strength. The larger m is, the higher the reliability is. For impregnated graphite, m is generally 10-15. The present invention takes the middle value m=12.3 and sets σ max ≤0.6σ b When the failure probability P f <0.02%, which can meet the sealing reliability requirements under extreme working conditions.

[0125] The maximum contact stress σ given in step S203 max The precise calculation formula realizes the scientific quantitative control of the maximum contact stress, which is a key breakthrough in the transition of seal design from empirical estimation to quantitative control. It can prevent the local stress of the graphite head from exceeding the limit and extend the service life of the graphite parts by more than 3 times.

[0126] As a refinement of the above embodiment, step S3 specifically includes:

[0127] When any of the verification conditions in steps S201 to S203 is not met, parameter adjustment is triggered in order of priority, and a qualified judgment conclusion and a recommended parameter combination set are output.

[0128] In some embodiments, the parameter adjustment priority order in step S3 is:

[0129] Adjust the angle α (±2°) → replace the O-ring diameter d0 → modify the reference distance h.

[0130] In some embodiments, when the recommended parameter combination set is output in step S3, the inclination angle α is subjected to multi-objective optimization based on the sealing force ratio, and the NSGA-II algorithm is used to solve the Pareto optimal solution set, and the recommended value of α and its tolerance range (±0.5°) are output. The expression is:

[0131]

[0132] In some embodiments, when the recommended parameter combination set is output in step S3, the compression rate adjustment priority rule is:

[0133] When δ r When the standard value is exceeded, adjust Δ r , adjust the step size Δ step satisfy:

[0134] Δ step =0.1·min(|Δ r -0.11D g |,|Δ r -0.15D g |);

[0135] When δ a When the standard value is exceeded, h should be adjusted first, and the installation reference distance modification amount should meet the following requirements:

[0136] Δh=0.5·(δ a -18% )·d0;

[0137] When Δ r Or if h is adjusted to the design limit but still cannot meet the compression rate requirements or the compression rate ratio still exceeds the limit, then adjust d0. Standard specifications should be selected for d0 to avoid cost increases caused by non-standard customization.

[0138] Example 2

[0139] A calibration and determination system for a bidirectional sealing structure of a wedge-shaped pressure ring and O-ring of a graphite heat exchanger, comprising:

[0140] Parameter input module: verify the integrity of medium parameters, material properties, and geometric dimensions;

[0141] Core calculation engine: executes the bidirectional sealing force verification, compression rate collaborative verification and graphite contact stress safety judgment of the method;

[0142] Dynamic Optimizer: adjusts parameters in the order of adjusting the optimal tilt angle, changing the O-ring diameter, and modifying the reference distance;

[0143] Result output module: outputs the recommended parameter set.

[0144] In addition, the output result module in the above-mentioned verification and judgment system also generates a three-dimensional design space solution set. The specific method includes:

[0145] 1) Define the design variables: X = (α, d o ,h,Δ r );

[0146] 2) Constraints: sealing force requirements, compression rate range, and stress threshold;

[0147] 3) Visualization method: The Pareto front solution is projected in a four-dimensional hypercube and the preferred area with a safety margin ≥ 20% is marked.

[0148] Example 3

[0149] The disclosed embodiment also provides a calibration and determination device for a bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger, comprising a processor and a memory. Optionally, the device may further comprise a communication interface and a bus. The processor, the communication interface, and the memory may communicate with each other via the bus. The communication interface may be used for information transmission. The processor may call the logic instructions in the memory to execute the calibration and determination method for the bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger of the above embodiment.

[0150] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0151] Memory, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. The processor executes the program instructions / modules stored in the memory to perform functional applications and data processing, thereby implementing the verification and determination method for the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger in the above-mentioned embodiment.

[0152] The memory may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Furthermore, the memory may include high-speed random access memory and non-volatile memory.

[0153] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for checking and determining the bidirectional sealing structure of a wedge-shaped pressure ring and O-ring of a graphite heat exchanger, characterized in that: The following steps are involved: Determine the structural parameters required for sealing performance verification and use an inclination calculation model with temperature and pressure compensation to determine the optimal inclination angle of the wedge-shaped groove surface of the upper and lower pressure rings; Conduct bidirectional sealing structure verification and assessment, including bidirectional sealing force verification, compression ratio coordination verification, and graphite contact stress safety assessment, specifically including: The bidirectional sealing force verification calculates the radial sealing force and the effective axial sealing force by decomposing the axial preload force, and judges whether the radial sealing force and the effective axial sealing force meet the verification conditions according to the dynamic safety factor and the preload force of the pressure ring bolt. The compression rate collaborative check calculates the radial compression rate and the axial compression rate of the O-ring, and verifies and determines whether the radial compression rate and the axial compression rate meet the specified requirements according to the set threshold range; The graphite contact stress safety determination is performed by calculating the maximum contact stress between the O-ring and the graphite head and taking into account the anisotropy correction coefficient to limit the maximum contact stress to within the allowable range; When any of the verification or safety judgments in the bidirectional sealing structure is not satisfied, the parameters are adjusted in the order of adjusting the inclination angle of the wedge-shaped pressure ring groove, replacing the diameter of the free section of the O-ring, and adjusting the distance from the axial installation reference surface to the center of the O-ring, and a parameter set that meets the verification judgment of the bidirectional sealing structure is output.

2. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 1 is characterized in that: The structural parameters required for sealing performance verification include: outer diameter of graphite head, inclination angle of wedge-shaped pressure ring groove, shell-side design pressure of graphite heat exchanger, shell-side design temperature of graphite heat exchanger, and graphite bending strength. The inclination angle of wedge-shaped pressure ring groove is in the range of [15°, 25°]. The tilt angle calculation model with temperature and pressure compensation is a temperature-pressure coupling constraint equation, and the specific formula is as follows: α=20°+0.08(T-80℃)-0.1P,(T∈[50,200]℃,P∈[0.1,2.0]MPa), Among them, α represents the inclination angle of the wedge-shaped pressure ring groove, T represents the shell-side design temperature of the graphite heat exchanger, and P represents the shell-side design pressure of the graphite heat exchanger.

3. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 2 is characterized in that: The calculation formula for radial sealing force and effective axial sealing force is: Among them, F r Indicates radial sealing force, F a Indicates the axial preload force of the pressure ring, F a ' represents the effective axial sealing force, μ1 is the measured friction coefficient between the O-ring and the graphite head, and μ2 is the friction coefficient between the O-ring and the metal pressure ring; The calibration conditions are as follows: Where: D g is the outer diameter of the graphite head, S f is the dynamic safety factor, is the pre-tightening force of the compression ring bolt.

4. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 3 is characterized in that: The friction coefficient μ2 is corrected using the following method: μ2(T)=μ 2,20℃ ·[1+0.002(T-293)](T∈[253,473]K) Among them, μ 2,20℃ Expressed as the friction coefficient between the O-ring and the metal pressure ring at 20°C.

5. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 3 is characterized in that: The calculation formula and verification formula of the radial compression rate and axial compression rate of the O-ring are as follows: Among them, δ r Indicates the radial compression rate of the O-ring, Δ r Indicates the radial compression of the O-ring after installation, δ a It represents the axial compression rate of the O-ring, d0 represents the cross-sectional diameter of the O-ring in the free state, and h represents the distance from the axial mounting reference surface to the center of the O-ring.

6. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 5, characterized in that: The maximum contact stress between the O-ring and the graphite head is calculated as follows: Among them, L c represents the equivalent effective contact half-width, σ max Indicates the maximum contact stress, K anis represents the anisotropy correction coefficient, σ b Indicates the bending strength of graphite, E g is the elastic modulus of graphite material at design temperature, E o is the elastic modulus of the O-ring material at the design temperature, ν g is the Poisson's ratio of graphite material, ν o is the Poisson's ratio of the O-ring material, E g,radial is the radial elastic modulus of graphite material, E g,axial is the axial elastic modulus of graphite material.

7. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 6, characterized in that: The safety judgment condition of the maximum contact stress is based on the Weibull failure probability model, and the formula is as follows: P f =1-exp[-(σ max / σ b ) m ] Among them, P f represents the failure probability, m is the Weibull modulus, and its value range is [10,15]; When σ max ≤0.6σ b When the failure probability is less than 0.02%, the safety judgment is passed.

8. The method for checking and determining the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of a graphite heat exchanger according to claim 7 is characterized in that: The multi-objective optimization of the inclination angle of the wedge-shaped pressure ring groove in the recommended parameter set is based on the sealing force ratio, and the specific expression is: The adjustment priority rules for the O-ring radial compression rate and the O-ring axial compression rate in the recommended parameter set are as follows: When δ r When the standard value is exceeded, adjust Δ r , adjust the step size Δ step satisfy: D step =0.1 min(|Δ r -0.11D g |,|D r -0.15D g |), When δ a When the standard value is exceeded, h should be adjusted first, and the distance modification Δh from the axial installation reference surface to the center of the O-ring should meet the following requirements: Δh=0.5·(δ a -18%)·d0, When Δ r Or if h is adjusted to reach the design limit but still cannot meet the compression ratio requirement or the compression ratio ratio still exceeds the limit, d0 is adjusted.

9. A calibration and determination system for a bidirectional sealing structure of a wedge-shaped pressure ring and O-ring of a graphite heat exchanger, characterized in that: include: Parameter input module: verify the integrity of medium parameters, material properties, and geometric dimensions; Core computing engine: executes the bidirectional sealing force verification, compression rate collaborative verification and graphite contact stress safety judgment of the method described in any one of claims 1 to 8; Dynamic optimizer: adjusts parameters in the order of adjusting the optimal wedge-shaped pressure ring groove angle, changing the O-ring free state section diameter, and modifying the distance from the axial installation reference surface to the O-ring center; Result output module: outputs the recommended parameter set.

10. A device for checking and determining the bidirectional sealing structure of a wedge-shaped pressure ring and an O-ring of a graphite heat exchanger, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the calibration and determination method of the bidirectional sealing structure of the wedge-shaped pressure ring and O-ring of the graphite heat exchanger as described in any one of claims 1 to 8 when running the program instructions.

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