The Interaction of Hydrogen Jet Releases with Walls and Barriers

It has been suggested that separation or safety distances for pressurised hydrogen storage can be reduced by the inclusion of walls or barriers between the hydrogen storage and vulnerable plant or other items. Various NFPA codes (1) suggest the use of 60 inclined fire barriers for protection against jet flames in preference to vertical ones. This paper describes a series of experiments performed in order to compare the performance of 60 barriers with that of 90 barriers. Their relative efficiency at protecting from thermal radiation and blast overpressure was measured together with the propensity for the thermal radiation and blast overpressure to be reflected back to the source of the leak. The work was primarily focused on compressed H2 storage for stationary fuel cell systems, which may be physically separated from a fuel cell system or could be on board such a system. Different orifice sizes were used to simulate different size leaks and all releases were made were from storage at 200 bar. Overall conclusions on barrier performance were made based on the recorded measurements.