Study of potential leakage on several stressed fittings for hydrogen pressures up to 700 bar

International audienceIn order to improve risk analyses and influence the design of the future H2 systems, an experimental study on 'real' leaks qualification and quantification was performed. In H2 energy applications, fittings appeared as a significant leakage potential and subsequently explosion and flame hazards. Thus, as a part of the 'Horizon Hydrogene Energie' French program, four kinds of commercial fittings usually employed on H2 systems were tested thanks to a new high pressure test bench - designed, setup and operated by INERIS - allowing experiments to be led for H2 pressures until 700 bar. The fittings underwent defined stresses representative of H2 systems lifetime and beyond. The associated leaks - when existing - are characterized in terms of flow rate

Fire risk on high-pressure full composite cylinders for automotive applications

International audienceIn the event of a fire, the TPRD (Thermally activated Pressure Relief Device) prevents the highpressure full composite cylinder from bursting by detecting high temperatures and releasing the pressurized gas. The current safety performance of both the vessel and the TPRD is demonstrated by an engulfing bonfire test. However, there is no requirement concerning the effect of the TPRD release, which may produce a hazardous hydrogen flame due to the high flow-rate of the TPRD. It is necessary to understand better the behavior of an unprotected composite cylinder exposed to fire in order to design appropriate protection for it and to be able to reduce the length of any potential hydrogen flame. For that purpose, a test campaign was performed on a 36 L cylinder with a design pressure of 70 MPa. The time from fire exposure to the bursting of this cylinder (the burst delay) was measured. The influence of the fire type (partial or global) and the influence of the pressure in the cylinder during the exposure were studied. It was found that the TPRD orifice diameter should be significantly reduced compared to current practice

Fire risk on high-pressure full composite cylinders for automotive applications

International audienceIn the event of a fire, the TPRD (Thermally activated Pressure Relief Device) prevents the high-pressure full composite cylinder from bursting by detecting high temperatures and releasing the pressurized gas. The current safety performance of both the vessel and the TPRD is demonstrated by an engulfing bonfire test. However, there is no requirement concerning the effect of the TPRD release, which may produce a hazardous hydrogen flame due to the high flow-rate of the TPRD. It is necessary to understand better the behavior of an unprotected composite cylinder exposed to fire in order to design appropriate protection for it and to be able to reduce the length of any potential hydrogen flame. For that purpose, a test campaign was performed on a 36 L cylinder with a design pressure of 70 MPa. The time from fire exposure to the bursting of this cylinder (the burst delay) was measured. The influence of the fire type (partial or global) and the influence of the pressure in the cylinder during the exposure were studied. It was found that the TPRD orifice diameter should be significantly reduced compared to current practice

EUROPEAN PRE-NORMATIVE RESEARCH PROJECT ON INHERENTLY SAFER USE OF HYDROGEN AND FUEL CELL INDOORS: KNOWLEDGE GAPS AND PRIORITIES

To develop safety strategies for the use of hydrogen indoors, the HyIndoor project is studying the behavior of a hydrogen release, deflagration or non-premixed flame in an enclosed space such as a fuel cell or its cabinet, a room, or a warehouse.The paper proposes a safety approach based on safety objectives that can be used to take various scenarios of hydrogen leaks into account for the safe design of Hydrogen and Fuel Cell (HFC) early market applications. Knowledge gaps on current engineering models and unknown influence of specific parameters were identified and prioritized, thereby re-focusing the objectives of the project test campaign and numerical simulations. This approach will enable the improvement of the specification of openings and use of hydrogen sensors for enclosed spaces. The results will be disseminated to all stakeholders, including hydrogen industry and RCS bodies.JRC.F.2-Cleaner energ