This paper was presented at the Seventh International Conference of Hydrogen Safety (ICHS 2017) in Hamburg on 11-13 September 2017. The paper presents results from an experimental study of vented hydrogen deflagrations in 20-foot ISO containers. The scenarios investigated include 14 tests with explosion venting through the doors of the containers, and 20 tests with venting through openings in the roof. The parameters investigated include hydrogen concentration, vent area, type of venting device, and the level of congestion inside the containers. All tests involved homogeneous and initially quiescent hydrogen-air mixtures. The results demonstrate the strong effect of congestion on the maximum reduced explosion pressures, which typically is not accounted for in current standards and guidelines for explosion protection. The paper is a deliverable from the project “Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations”, or HySEA (www.hysea.eu), which receives funding from the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) under grant agreement no. 671461. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and United Kingdom, Italy, Belgium and Norway.

The paper is a deliverable from the project "Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations", or HySEA (www.hysea.eu), which receives funding from the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) under grant agreement no. 671461. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and United Kingdom, Italy, Belgium and Norway. The paper is included in the Proceedings from the Seventh International Conference on Hydrogen Safety (ICHS 2017), ISBN 978-88-902391, pp. 591-603.