Fracture Mechanics Assessment of Hydrogen Storage Vessel

High strength steel is usually used in fabrication of hydrogen storage vessel. The fracture toughness of high strength steel will be decreased and the crack sensitivity of the structures will be increased when high strength steels are applied in hydrogen environment with high pressure. Hence, the small cracks on the surface of pressure vessel may grow rapidly then lead to rupture. Therefore, this paper makes a series of research on how to evaluate the 4130X steel hydrogen storage vessel with fracture mechanics. This study is based on the assumption that there is a semi-elliptic crack on internal surface of hydrogen storage vessel. First of all, based on linear elastic fracture mechanics, the stress intensity factors and crack tolerance of 4130X steel hydrogen storage vessel have been calculated by means of finite element method based on interaction integral theory and polynomial-approximated approach from GB/T 34019 Ultra-high pressure vessels. Then, a comparative study has been made from the results of above methods to find out the difference between them. At last, the fatigue life of a 4130X steel hydrogen storage vessel has been predicted based on linear elastic fracture mechanics and Paris formula. The calculation methods and analysis conclusion can be used to direct the design and manufacture of hydrogen storage vessel.

Numerical Simulation on Fire Test of 45 MPa Hydrogen Storage Vessels for Hydrogen Stations

In recent years, there have been a number of fire and explosion accidents of hydrogen storage vessels in hydrogen stations all over the world. China is vigorously developing the hydrogen fuel cell vehicle industry. At present, more than 80 hydrogen refueling stations have been built, and 1000 hydrogen refueling stations are planned to be built in 2025. In order to study the response law and pressure relief requirements of hydrogen storage vessels in hydrogen refueling stations under fire condition, fire tests of hydrogen storage vessels filled with high pressure hydrogen is planning to carry out. In this paper, numerical simulation of fire tests of hydrogen storage vessels was carried out. The hydrogen storage vessel is a horizontal single-layer seamless structure with working pressure of 45 MPa, wall thickness of 35.4 mm, volume of 205 L and material of 4130X. Propane is used as fuel for fire test. Based on CFD software, the thermal structural response calculation model of the hydrogen storage vessel under fire condition was established. The response law of hydrogen temperature rise and pressure rise in the hydrogen storage vessel was analyzed, and the influence of filling medium, filling pressure and ambient temperature on the hydrogen storage vessel was studied. The research results provide technical guidance for the subsequent fire test of the hydrogen storage vessels.