InsHyde - Hydrogen Releases in Confined and Partially Confined Spaces

In the first year of HySafe the “safety  vote” of the PIRT exercise and the expert survey have pointed out that releases (even slow releases, with “small” release rates) of hydrogen in confined or partially confined geometries represent a serious risk, since combustible mixtures may form, which, if ignited, could lead to explosions and even to detonations. Thus, it is necessary to study different configurations of release (position, release rate) and the accompanying sensor equipment and mitigation devices (ventilation or other ways of enhancing mixing, inertisation, active ignition or recombination). The InsHyde program has been initiated during the 2nd JPA to address this need.

After the restructuring of the InsHyde program following the first HySafe review by EC in 2005, significant progress has been made in InsHyde. An experimental and simulation matrix has been set-up and first large scale experiments in the frame of InsHyde have been started. Sensor evaluation, combustion experiments and draft recommendations will complete this picture in this period.

There is an obvious link between confined environment and settings like residential garages or repair shops, where one has to prove that several kilograms of hydrogen can be stored safely. Here one has to account for imperfections either on the side of the vehicle or on the building itself. Figures on maximum allowable leakage rate or maximum tolerable explosive volumes are lacking.

Experience can possibly be gained from the existing concepts for natural gas driven vehicles. This experience should be assessed and if possible translated to the usage of hydrogen.

Project learning will be transferable to both vehicle as well as stationary applications such as fuel cell that can be used in dwellings for heat and electricity production.