Optimizing Sealing Structure Design for Enhanced Sealing Performance in Type IV Hydrogen Storage Vessels

This study conducts a finite element analysis (FEA) to assess the sealing performance of type IV hydrogen storage vessels, focusing specifically on the viscoelastic properties of the liner material. The analysis aims to quantify the impact of key parameters, including sealing interface design, O-ring pre-compression, and liner thickness, on overall sealing integrity. Through detailed modeling of the interactions among the metal boss, polymer liner, and sealing ring, the study shows that ignoring the viscoelastic response of the polymer liner can result in a significant underestimation of radial deformation, by a factor of 0.4–0.5. Furthermore, the increasing thickness of the liner wall in the vessel mouth area intensifies deformation within the sealing zone, thereby increasing the potential for leakage. The presence of an annular groove at the interface between the metal seat and polymer liner is critical for effective sealing, generating contact stresses that meet the operational requirements at 52 MPa. Moreover, the O-ring's sealing effectiveness is highly sensitive to the initial compression rate, achieving optimal performance at rates above 16%. These findings offer valuable insights for enhancing the reliability of component joints under high-pressure conditions, critical for ensuring the safety and operational efficiency of type IV hydrogen storage vessels.