Thermal Protection and Fire Resistance of High-Pressure Hydrogen Storage

摘要

The paper focuses on the main unresolved safety issue for hydrogen-powered vehicles, i.e. the fire resistance of onboard hydrogen storage. The experimental study supported by numerical analysis has been undertaken in order to achieve fire resistance rating of high-pressure hydrogen tank beyond potential car fire duration, i.e. of the order of 2 hours. The experimental programme comprised of bonfire tests of carbon-fibre reinforced plastic tanks with polymer liner both bare and thermally protected, in line with Global Technical Regulation on Hydrogen and Fuel Cell Vehicles #13. Tested parameters included different levels of thermal protection, different bonfire heat release rates, tanks with and without prehistory of pressure cycling. It was experimentally demonstrated that the thermal protection solution in form of epoxy-based intumescent paint is capable to increase fire resistance rating of carbon-fibre plastic tank from current 6-12 minutes to beyond 2 hours. This breakthrough achievement in fire resistance rating of onboard hydrogen storage has a potential to impact on safety design of tanks and to reduce range of hazards in case of accident scenario like a car fire, e.g. complete elimination of catastrophic tank rapture in a fire or longer release from a pressure relief device resulting in a shorter hydrogen jet fire. Smaller bonfire heat release rate was shown to increase fire resistance rating of the tested tank though still complying with the Global Technical Regulation #13. Tank pressure cycling did not have impact on the tank fire resistance rating.