Seal Performance Research Articles

Thermo-Mechanical Properties and Benefits of Borosilicate Glass for SOEC Sealants

Boro-silicate glass materials have ideal properties for sealing oxidizing and reducing environments and electrically insulating solid oxide electrolysis cells (SOEC), while maintaining a glassy phase at high temperatures (750-900°C) to minimize chemo-mechanical degradation and gas permeability 1,2. Glass seals are typically applied as a slurry; hence, they are also expected to have non-wetting properties to prevent glass infiltration into the porous electrode structures during manufacturing 3. During the first startup, the initial temperature ramp serves to evaporate any binder in the slurry and to go through the glass transition phase, which cures the glass and increases hardness to improve resistance to creep. Typical glass materials operate in visco-plastic regimes (i.e., beyond the material’s glass transition temperature) and must be chemically stable while operating in steam-rich and oxygen-rich environments. To fully understand the performance of borosilicate glass seals, optimize the manufacturing, assembly, and maintenance of SOEC, we must be able to measure and analyze the glass material properties (i.e., glass transition temperature, coefficient of thermal expansion, modulus, creep, hardness) at the same operating conditions relevant for SOEC operation. In this work, we characterize the thermo-mechanical properties of borosilicate glass powder and sintered samples at various temperatures (ranging from ambient to 850°C), and at different aging conditions (i.e., atmosphere composition, temperature, and duration). The atmosphere composition is changed between air, steam-N2 mixtures, and H2-N2 mixtures to evaluate the chemical stability of borosilicate glass relating to the possible depletion of boron and silicon via the formation of boron hydroxide and silicon vapor when exposed to steam- and hydrogen-rich environments. The aging temperature and duration is varied to evaluate the crystallization kinetics, particle size growth, and its effect on mechanical properties. We employ a combination of Simultaneous Thermal Analysis - STA (i.e., combined Thermogravimetric Analysis - TGA, Differential Scanning Calorimetry - DSC, Fourier Transform Infrared - FT-IR spectroscopy, and Quadrupole Mass Spectroscopy - QMS), and nanoindentation as characterization techniques, while surface roughness is estimated with a 3D confocal optical microscope.Surface roughness varies between 0.83-1.38 𝜇m ± 1.1-1.76 𝜇m (Sa ± Sq). Both powder and solid samples are analyzed via STA with sequential temperature ramps (constant heating rate at 10 K/min in Ar atmosphere) up to 1500°C to estimate the effect of crystallization and particle size on the glass transition onset. For a sample aged at 850°C for 340 h, the first ramp shows typical DSC exothermic peaks (mW/mg) at around 800°C, with a midpoint glass transition occurring at 900°C. However, on the second ramps, peaks lower to around 500°C and the glass transition is estimated to be around 700°C. Subsequent tests consistently mirrored the trend of the second temperature ramp, showing minimal deviation and influence of crystallization and particle growth. Nanoindentation is performed between room temperature and 600°C to characterize both sintered glass samples “as-received” and aged at temperatures between 750-950°C for 340 h. Comparing a sample aged at 750°C with an “as-received” sample, the elastic moduli equally decreased from 100 GPa at room temperature to 40 GPa at 600°C, with comparable hardness values ranging from 10 GPa at room temperature to 0.5-0.9 GPa at 600°C, respectively. A.G. Sabato, G. Cempura, D. Montinaro, A. Chrysanthou, M. Salvo, E. Bernardo, M. Secco, F. Smeacetto, Journal of Power Sources, 328, 262-270 (2016)Dilshat U. Tulyaganov, Allu Amarnath Reddy, Vladislav V. Kharton, José M.F. Ferreira, Journal of Power Sources, 242, 486-502 (2013)S.-B. Sohn, S.-Y. Choi, G.-H. Kim, H.-S. Song, G.-D. Kim, Stable sealing glass for planar solid oxide fuel cell, J. Non. Cryst. Solids. 297 (2002) 103–112. doi:10.1016/S0022-3093(01)01042-0 Figure 1

Preparation and characterization of a chitosan-gentamicin derivative and its effect on tropical fruit preservation

Applications of chitosan (CS) are hindered by its weak antimicrobial ability, poor solubility in basic and neutral solutions, structural modification is needed to improve its functional properties. Herein, a new chitosan-gentamicin derivative (CS-GT) was successfully synthesized via protection, regioselective bromination, nucleophile substitution reaction, and deprotection. Characterization techniques confirmed the successful introduction of GT onto the C-6 position of CS with a grafting rate of 76.19%. The additional amino groups provided by GT decreased the crystallinity and thermal stability of CS-GT, while enhancing its solubility in neutral and alkaline solutions. Compared to CS, CS-GT exhibited 2.50 and 2.41 times higher antibacterial activities against Escherichia coli and Staphylococcus aureus, respectively. Besides, an active packaging coating was develop by incorporating glycerol into CS-GT. The hydrogen bond networks formed within coatings endowed them good thermal stability and tightly uniform morphology. Furthermore, increasing CS-GT from 1% to 3% improved the coating's ultraviolet resistance and flexibility, but reduced its waterproof performance, visual appearance, and water barrier properties. Preservation experiments with papaya and litchi showed that CS-GT coatings effectively inhibited microbial growth and maintained quality and appearance up to 16 and 8 days of storage, respectively. In conclusion, CS-GT show promising potential for applications in food packaging.

Waterproof flexible strain sensors with high sensitivity for detecting human movement, airflow size and water ripples prepared by demulsification

Carbon nanotubes (CNTs) have found extensive applications as conductive fillers in the fabrication of flexible strain sensors; however, their propensity to agglutinate often leads to non-uniform distribution within flexible matrix. In this study, we propose a method of demulsifying while adsorbing and fixing carbon nanotubes to prepare a conductive composite based on polyacrylic resin and carbon nanotube with uniform dispersion. Due to its distinctive surface structure, the flexible strain sensor based on this conductive composite exhibits simultaneous positive and negative strain effects, resulting in exceptional sensitivity (ranging from 4.86 to 140.68), ultra-high detection limit (13 mg), and long durability (stretched 12,000 times and compressed 10,000 times). This sensor can be used for detecting small strains such as airflow and pulses as well as larger stresses such as various joint movements in human physiological activities. Meanwhile, the sensor exhibits exceptional waterproof performance, enabling its suitability for water-related sensor detection tasks such as monitoring water wave oscillations and measuring the rotational speed of water. Furthermore, due to its high conductivity properties, this conductive composite material can also be utilized for Joule heating.

Analysis and structural optimization of tree-type dynamic pressure groove mechanical seal performance

Abstract This study investigates the influence of the order and groove ratio of a tree-shaped groove on the sealing performance of a mechanical seal system using numerical simulations. A three-dimensional geometric model of the tree-shaped groove is established using SOLIDWORKS, and the mesh is divided in ANSYS Meshing before being imported into Fluent software for analysis. The single-factor experimental method is employed to evaluate the impact of different parameters on the opening force and leakage rate by varying one parameter while keeping others constant. The simulation results reveal that in the low-speed range, the tree-shaped groove with a groove ratio of 3:4:5 exhibits a larger opening force. Conversely, in the high-speed range, the three-stage tree-shaped groove with a groove ratio of 1:1:1 demonstrates a lower leakage rate and a larger opening force. The findings highlight the significant impact of the order and groove ratio of the tree-shaped groove on the sealing performance of the non-contact mechanical seal. The three-stage tree-shaped groove outperforms the second and fourth stages in terms of mechanical sealing performance, particularly in regard to the opening force. This study provides valuable insights into optimizing the design of tree-shaped grooves in mechanical seal systems to enhance their overall performance and efficiency.

Preparation and Properties of GMS/HTSF-Modified Waterborne Polyurethane Fluorine-Free Waterproof and Breathable Film.

Developing a fluorine-free, durable, high-performance waterproof breathable film for fabrics remains a formidable challenge. In this paper, a strategy for the preparation of fluorine-free, durable, and high-efficiency fabric waterproof and breathable membranes using glyceryl monostearate (GMS)/double-ended hydroxy silicone oil (HTSF)-modified waterborne polyurethane was proposed. The orderly orientation of GMS and HTSF gives the fabric excellent water-repellent properties, and the polyurethane macromolecular chain ensures strong adhesion of long-chain alkanes and silicones to the fabric surface. In this paper, the effects of different GMS contents on the stability, chemical structure, particle size, viscosity, water absorption performance, surface morphology, and XPS of a waterborne polyurethane fluorine-free waterproof and breathable membrane (GHWPU) were studied. At the same time, the application properties of GHWPU-treated fabrics, such as waterproof performance, antifouling performance, surface energy, morphology, and air permeability, were discussed. Through the analysis of SEM and XPS, it was found that the folds on the surface of the film were more and more orderly with the increasing content of GMS, and this orderly distribution of water-repellent groups endowed the film with excellent water-repellent ability. When the GMS content was 28 wt %, the finished fabrics had excellent comprehensive properties such as static contact angle of 141.6°, hydrostatic pressure of 96.7 KPa, resistance to more than 30 washes, and air permeability of 119.3 mm/s.

A Study on the Steady and Dynamic Performance of Dry Gas Seals with Combined Superelliptical Grooves and Holes on the End Face

Background:: Enhancing the stability and leakage control of Dry Gas Seals (DGS) under high parameters has been a crucial research focus. The design of end-face groove structures and surface texture shapes has been an essential aspect of DGS studies aimed at improving performance. Objective:: The proposed end-face gas seal utilizes superelliptical grooves and holes to improve its performance, aiming to obtain a patent. The use of superelliptical curves allows for a more precise and efficient geometric representation, resulting in a better sealing effect. Methods:: A theoretical analysis model for the steady and dynamic behavior of the seal is established using the lubrication theory and perturbation methods. The study investigates the distribution patterns of gas film pressure on the sealing end-face and gas flow characteristics within the film. This approach provides a new perspective for understanding seal performance and offers a theoretical basis for optimizing seal design. Results:: The results indicate that the combined end-face structure with grooves and holes ensures good sealing stability and effectively enhances leakage control performance. By optimizing the design of the superelliptical groove and holes on the end face, the performance of DGS can be significantly improved. Conclusion:: Within the parameter range studied, better steady-state performance is achieved for θ=40~80°, v=1.3~1.4, u=1~2, β=0.6~0.7, and λ=1.0~1.5. In addition, better dynamic performance is observed for θ=80~120°, v=1.1~1.2, u=2~3, β=0.9~1.0, and λ=2.0~2.5.

A comparative study on rotordynamics characteristics of hole-pattern damping seals with different cavity shapes

PurposeThe purpose of this paper is to improve the seal performance by proper design of the cavity shape of the damping holes, especially the rotordynamics characteristics of the hole-pattern damped seal (HPDS).Design/methodology/approachA new damping seal structure that comprises a circle-shaped cavity and two directional leaf-shaped cavities with a dovetail-shaped diversion groove is proposed. The comparative study on the sealing characteristics of dovetail-shape, leaf-shape and classical circular HPDSs was carried out using ANSYS CFX.FindingsThe dovetail-shaped HPDS significantly outperformed two other damping seal designs in leakage and rotordynamic performance. At a rotating speed of 7,500 rpm, it showed a 25% reduction in leakage, a 23% increase in average effective damping and a 119% increase in average effective stiffness. The cross-coupled stiffness Kxy shifted from positive to negative, reducing circumferential flow. The dovetail's inclined leaf-shaped grooves create a double vortex that slows jet velocity in the seal clearance and alters spiral flow direction, resulting in a uniform pressure distribution and enhanced rotor stability at low frequencies.Originality/valueThis study proposes a novel HPDS with dovetail-shaped diversion grooves. The seal can realize the simultaneous improvement of rotordynamics and leakage characteristics compared to the current seal structure.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2024-0127/

Study of UV-cured tung oil-based polyalcohol resin with isophorone diisocyanate as crosslinker

Petroleum-based resins are associated with increasing energy demands and biodegradability issues. Resins produced from biomass raw materials are a suitable alternative and hold significant potential across various applications, including the manufacture of molding materials, oil-based resins, and adhesives. Particularly in the field of coatings, biomass-based resins are recognized for their environmental friendliness and renewability, although there remains room for improvement in terms of strength and curing speed compared with petroleum-based resins. In this study, we developed a high-strength tung oil-based polyurethane photocurable resin (TOPP). To produce the resin, tung oil was first converted into tung oil polyol, and then acrylic ester along with isophorone diisocyanate was used as a bridging agent to confer photocuring properties. Analysis via infrared and nuclear magnetic resonance spectroscopy confirmed the TOPP structure and demonstrated the reaction of carbon–carbon double bonds to form polyol. TOPP exhibited impressive mechanical properties, including a tensile strength of 21.02 MPa and an elastic modulus of 954.63 MPa, achieved through the optimization of the amount of hydroxyethyl methacrylate added. Additionally, TOPP exhibited excellent hydrophobicity with a maximum water contact angle of 88.78° and a low thermal conductivity of 0.26 W·(mK)−1. As a wood coating, TOPP significantly enhanced resistance to oil and improved waterproof performance. The curing speed was notably accelerated without emissions of volatile solvents, which demonstrates the substantial potential of the resin for coating applications on wooden products, particularly in the furniture industry.

Study on the effects of three surface imperfections on the performance of O-ring seals based on the finite element method

The performance of O-rings is crucial to the large variety of core equipment or components that employ O-ring seals. O-ring surface imperfections that meet quality standards are allowed to be put into service. However, the presence of surface imperfections will inevitably affect the performance of the O-ring seal. To this end, in this study, nonlinear finite element models of O-ring structures with an ideal circular cross section and three surface imperfections of parting line projection, backrind, and excessive trimming in accordance with ISO standards are developed. On this basis, their contact conditions and stress distributions are calculated, analyzed, discussed, and compared. The results show that the maximum contact pressure in the area where the imperfection is located increases and that the presence of the imperfection does not reduce the sealing performance. Backrind under low pressure conditions and excessive trimming do not affect the maximum Von-Mises stress. While backrind under high pressure conditions and parting line projection can make the maximum Von-Mises stress increase significantly. In particular, at a fluid pressure of 10 MPa, backrind causes a 21% increase in the maximum Von-Mises stress, while parting line projection causes a 198% increase. Such a large increase in stress will increase the likelihood of fatigue failure and breakage.

High-temperature melt-infiltration preparation and erosion behavior of γ-Y2Si2O7 /Y2O3–SiO2–Al2O3 glass coating on porous Si3N4 ceramics

Dense γ-Y2Si2O7/Y2O3–SiO2–Al2O3 glass coatings were prepared on porous Si3N4 ceramics using high-temperature melt-infiltration preparation method to improve their stability in service environments, specifically including water resistance and erosion wear resistance. Evolution of structure and mechanical properties during coating preparation was studied. Damage mechanism in erosion wear process was illustrated by putting the coated samples into a high-speed water flow with quartz particles. Dense double-layer microstructure could be formed when sintering at 1350–1450 °C for 1 h. The proportion of each phase inside the coating material prepared by various sintering temperatures was different, resulting in different elastic modulus and hardness, and ultimately affected the erosion resistance of the coatings. The “plasticity index” (E/H value) of γ-Y2Si2O7/Y2O3–SiO2–Al2O3 glass coating prepared at lower temperature (1350 and 1400 °C) was low, and the erosion failure of the coating was brittleness mode, leading to an obvious decrease on waterproof performance after erosion test. While coating prepared at higher temperature (1450 °C) showed a better erosion resistance. After erosion for 2 h, water absorption of coating surface was changed by only 1.34 %. Micro-morphology of the coating was almost unchanged before and after erosion, maintaining excellent waterproof performance.

Brush Seal Performance with Ideal Gas Working Fluid under Static Rotor Condition

The study investigated how variations in pressure ratio affect the leakage flow of a brush seal for both contact and clearance structures, in which the clearance is measured as the distance between the bristles tip and the rotor surface. This investigation utilized the Reynolds-Averaged-Navier–Stokes (RANS) equations alongside a two-dimensional axisymmetric anisotropic porous medium model. To verify the model’s accuracy and dependability, the obtained results were compared with previous numerical results and experimental observations, showing a satisfactory level of agreement. The results indicate that the predominant pressure drop occurs downstream of the bristle pack with the clearance model exhibiting a higher leakage rate compared to the contact model. Leakage increases proportionally with the pressure ratio, while axial velocity gradually rises and radial velocity experiences a significant increase. In conclusion, the leakage in the brush seal contact structure is significantly lower than in the clearance structure, resulting in the best performance.

Simulation of the Static Sealing Performance of Rubber Packer Cylinders in a Supercritical–CO2 Environment

Simulation of the Static Sealing Performance of Rubber Packer Cylinders in a Supercritical–CO2 Environment

Numerical Optimization Analysis of Floating Ring Seal Performance Based on Surface Texture

Much research and practical experience have shown that the utilization of textures has an enhancing effect on the performance of dynamic seals and the dynamic pressure lubrication of gas bearings. In order to optimize the performance of floating ring seals, this study systematically analyzes the effects of different texture shapes and their parameters. The Reynolds equation of the gas is solved by the successive over-relaxation (SOR) iteration method. The pressure and thickness distributions of the seal gas film are solved to derive the floating force, end leakage, friction, and the ratio of buoyancy to leakage within the seal. The effects of various texture shapes, including square, 2:1 rectangle, triangle, hexagon, and circle, as well as their parameters, such as texture depth, angle, and area share, on the sealing performance are discussed. Results show that the texture can increase the air film buoyancy and reduce friction, but it also increases the leakage by a small amount. Square textures and rectangular textures are relatively effective. The deeper the depth of the texture within a certain range, the better the overall performance of the floating ring seal. As the texture area percentage increases, leakage tends to increase and friction tends to decrease. A fractal roughness model is developed, the effect of surface roughness on sealing performance is briefly discussed, and finally the effect of surface texture with roughness is analyzed. Some texture parameters that can significantly optimize the sealing performance are obtained. Rectangular textures with certain parameters enhance the buoyancy of the air film by 81.2%, which is the most significant enhancement effect. This rectangular texture reduces friction by 25.8% but increases leakage by 79.5%. The triangular textures increase buoyancy by 28.02% and leakage increases by only 10.08% when the rotation speed is 15,000 r/min. The results show that texture with appropriate roughness significantly optimizes the performance of the floating ring seal.

Analysis of Wear Characteristics of Hydrodynamic Seals During Startup Using 3D Fractal Characterization and Study of Opening Performance Degradation Mechanism

An experimental study was conducted to investigate the degradation mechanism of the opening performance of hydrodynamic seals during multiple startups, and a model was proposed to analyze the wear characteristics during the startup process. The study that the state evolution of the hydrodynamic seal during the single startup process occurs in five stages: low-speed and heavy-load stage, mid-speed and mid-load stage, high-speed and light-load stage, intermittent contact stage, and noncontact stage. The main factor that influences the deterioration of the initial performance of hydrodynamic seals during multiple startups is the decrease in the depth of the root groove. To prevent the heavy deterioration of the opening performance of the hydrodynamic seal, it is important that the remaining depth of the tip of spiral groove (TSG) is greater than 47.67% of the initial value and the dimensionless startup time should not exceed 0.42 for a complete passage through the mid-speed and mid-load stage.

Effect of rotating shaft vibration on lip seal performance

Rotary lip seals are important components in various rotating machinery and are inevitably affected by vibration. This paper introduces the first simulation model for rotary lip seals under radial sinusoidal vibration conditions based on the mixed lubrication theory. Using the proposed model, the effects of varying vibration amplitudes and frequencies on the tracking performance, leakage rate, and friction torque of lip seals were analyzed. The simulation results indicate that, the leakage rate exhibits an initial increase followed by decrease as the vibration amplitude increases, while the friction torque exhibits a decrease followed by increase. Excessively high vibration frequencies may induce separation between the lip and shaft surface, resulting in severe leakage.

The Effects of the Initial Geometrical Errors on the Piston Friction and Sealing Performance in a Buoyancy Regulator of an Underwater Glider

Abstract As an important power component of an underwater glider, the energy consumption of the buoyancy regulator directly affects the endurance of the underwater glider. The accurate calculation and prediction methods for the friction forces can be helpful for improving the working performance of the buoyancy regulator. The traditional friction prediction models consider the cylinder as perfect cylinder without any geometric error, which cannot accurately reflect the effects of the initial geometric defects on the friction force and sealing performance of the cylinder of the piston type buoyancy regulator. This article proposes a new friction force calculation method considering the initial geometrical defects of the cylinder. By using the theoretical analysis and finite element calculations, the effects of the initial geometrical defects on the friction force and sealing performance of the piston type buoyancy regulator can be more accurately analyzed. The effect of the ovality and taper on the friction force and sealing performance is analyzed. In addition, the friction force calculation method proposed in this article is validated by an experiment. This article can provide an accurate cylinder friction force calculation method considering the initial geometrical errors for the piston type buoyancy regulators.

Research on Evaluation Method of Water-blocking Powder Distribution Uniformity of Buffer Layer in HV Cable Based on Image Processing

Abstract High voltage (HV) cables are widely used in urban power transmission networks. The key component in HV cable, the buffer layer, has attracted lots of attention and more and more researchers are devoting to its material property evaluation and quality test techniques. A longitude water-blocking property evaluation method of buffer layer based on image processing is proposed in this paper. The microscopic images of the buffer layer are enhanced and morphologically processed. The area fraction method, entropy method, and fractal dimension method are used to evaluate the distribution characteristics of buffer layer water-blocking powder in binary images. This article innovatively proposes a more economical and convenient simulation method that can efficiently and accurately evaluate the waterproof performance of the buffer layer of high-voltage cables. With the proper use of the buffer layer, it can effectively protect the cables and improve the stability of power system operation.

A Study Into the Hot Tack and Cooled Seal Performance of Emerging Coated Papers for Primary Flexible Food Packaging

ABSTRACTIn response to the need to employ recyclable materials for food packaging, the resurgence of paper as a primary flexible packaging material is driven by consumer trust in paper and its renewable wood fibre composition, strengthened by a well‐established recycling infrastructure. A diverse range of coated papers and coatings has become accessible in the market, specifically tailored for applications in horizontal and vertical form‐fill sealing. Within the framework of the CORNET‐TETRA project HBC.2021.0288 REPAC2, a careful selection of 16 food‐grade coated papers and/or coatings, slated for introduction to the market either presently or within the next 2 years, has been undertaken. This study focused on evaluating the processing window for superior hot tack and cooled seal performance of coated papers, in relation with the composition of paper coatings as identified using Fourier transform infrared (FTIR) measurements, and their thermal softening or melting characteristics as identified through differential scanning calorimetry (DSC). Thermal behaviour in DSC thermograms is used to categorize the commercial coated papers into distinct classes. Class I papers, mainly with acrylic‐based coatings, exhibit high hot tack strengths (0.2–0.7 N/mm) and a glass transition temperature (Tg) close to the seal initiation temperature but do not considerably gain strength with further cooling. Class II papers are thermally inert in DSC with minimal thermoplastics, leading to weak seals. In contrast, classes III and IV, including wax‐based and polyolefin‐based or polyvinylalcohol‐based (PVOH) coatings, respectively, show low initial hot tack strengths that considerably increase upon adequate cooling. Particularly, the Class IV papers with polyolefin‐based coatings have well‐performing seals. Despite having relatively low hot tack strengths after cool times of 0.1 s, below 0.3 N/mm, high strengths can be obtained after adequate cooling with outliers reaching 0.74 and 1.14 N/mm. Additionally, the influences of seal parameters on seal performance were evaluated. The study reveals that cool time, seal pressure and, to a lesser extent, seal time significantly impact hot tack strength, consistent with prior research. The critical role of jaw temperature in heat conductive sealing is affirmed, as it dictates the efficacy of other seal parameters. Seal initiation occurs at 75°C for four papers, and nine others necessitate temperatures equal to or exceeding 100°C, with one paper only displaying seal initiation at 195°C. This variation highlights the requisite for tailored temperature windows for effective sealing of these papers. As such, deeper insights into the intricate interplay between coating composition, thermal properties and seal performance are obtained in order to support advances in sustainable packaging technology.

Theoretical Expression and Screening of Real Gas Effect of Spiral Groove Dry Gas Seal

The emergence of dry gas seals has revolutionized the form of fluid sealing. The traditional research and analysis of dry gas seals is carried out by considering the lubricating medium gas as an ideal gas, but at this stage, the sealing application environment is complicated, so it is necessary to consider the real gas effect of the lubricating medium gas to expand and break through the design system of dry gas seals. We choose seven common lubricating media in dry gas seal applications and screen the optimal density expression of the real gas using different real gas equations of state. Then, we study the extent to which the compression factors of different lubricating gases deviate from the ideal gas and analyze the errors of different real gas equations of state. These results can provide an optimal expression to clarify the mechanism by which the real gas effect affects the dry gas seal performance, which helps to grasp the nature of dry gas seals, predict the dry gas seal behavior, and guide the dry gas seal application.

Lightweight Type-IV Hydrogen Storage Vessel Boss Based on Optimal Sealing Structure

The seal and weight of the Type IV hydrogen storage vessel are the key problems restricting the safety and driving range of fuel cell vehicles. The boss, as a metal medium connecting the inner liner of the Type IV hydrogen storage vessel with the external pipeline, affects the sealing performance of the Type IV hydrogen storage vessel, and there is no academic research on the weight of the boss. Therefore, according to the force characteristics of the boss, this paper divides the upper and lower areas (valve column and plate). The valve column with seal optimization and light weight is manufactured with a 3D printing additive, while the plate bearing and transferring the internal pressure load is manufactured by forging. Firstly, a two-dimensional axisymmetric simulation model of the sealing ring was established, and the effects of different compression rates on its seal performance were analyzed. Then, the size and position of the sealing groove were sampled, simulated, and optimized based on the Latin Hypercube method, and the reliability of the optimal seal structure was verified by experiments. Finally, the Solid Isotropic Material with Penalization (SIMP) topology method was used to optimize the weight of the boss with optimal sealing structure, and the reconstructed model was checked and analyzed. The results show that the weight of the optimized boss is reduced by 9.6%.