ScholarWorks@중앙대학교

초록

High-pressure gaseous hydrogen storage vessels, which are typically made of low-alloy steel, are widely used at hydrogen refueling stations owing to their efficiency and the maturity of associated storage technologies. However, the storage vessels are susceptible to hydrogen embrittlement and fatigue damage, with the latter being caused by the cyclic charging-discharging process. For an accurate assessment of their structural integrity, it is important to evaluate fatigue crack growth (FCG) under realistic operating conditions. On the basis of a sequentially coupled heat transfer-structural analysis, this study assessed the structural integrity of a 350 L hydrogen storage vessel made of SA-372 steel. A one-dimensional thermodynamics-based numerical model was used to predict internal pressure and temperature variations, and the predictions were used in finite element simulations. The fatigue life and crack growth behavior were determined using linear elastic fracture mechanics, by considering hydrogen environment effects. The results showed that compared with circumferential cracks, longitudinal cracks led to higher stress intensity factors and shorter fatigue life. On the basis of these findings, an inspection strategy for determining the fatigue crack growth behavior and the location and orientation for cracks is proposed. This integrated framework for assessing the structural integrity of a hydrogen storage vessel provides a rational basis for fatigue life assessment and crack management under service-relevant conditions, and it can be used to enhance the safety and reliability of hydrogen infrastructure systems.

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