Research on protection methods for 70 MPa on-board Type IV hydrogen storage cylinders under localized fire conditions

When hydrogen fuel cell vehicles (HFCVs) occur fires, the localized fire protection methods for on-board hydrogen storage cylinders can reduce the failure possibility of cylinders. This paper describes an experimental study of 70 MPa Type IV on-board hydrogen storage cylinders exposed to localized and engulfing fires. A three-dimensional (3D) computational fluid dynamics (CFD) model is developed to simulate the effects of various protection methods on the heat transfer characteristics of cylinders. The results demonstrate that both fire-protection coatings and fire-protection baffles effectively reduce the maximum temperature of cylinder surfaces and enhance the fire resistance of cylinders under localized fire conditions. Specifically, using a 2 mm thick fire-protection coating and a circular fire-protection baffle with a width equal to 100% of the cylinder diameter proves to be more suitable protection methods. These measures significantly decrease the risk of explosion and leakage in Type IV hydrogen storage cylinders during localized fire conditions.