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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

RADIATIVE HEAT FLUX AND FLAMMABILITY ENVELOPE PREDICTIONS FROM UNINTENDED RELEASES OF HYDROGEN

Get access (open in a dialog) DOI: 10.1615/IHTC13.p26.70
12 pages

Abstract

The development and commercial use of hydrogen will require safety guidelines for building vehicle fuelling stations, storage facilities, and other infrastructure components. If the development of these safety guidelines is to be made on a scientific basis, then validated engineering models of unintended hydrogen releases are needed for scenario and risk analysis.
Unintended releases of hydrogen from high-pressure sources can produce hydrogen jet-flames and information about the variation of the thermal radiation exposure with distance from the flame is important in determining safe distances for handling and storage. An equally important issue is the determination of the concentration decay of an unignited hydrogen jet in surrounding air, and the envelope of locations where the concentration falls below the point where ignition can no longer occur (lower flammability limit).
This paper presents models and results for the radiative heat transfer from hydrogen jet flames and the concentration decay of unignited hydrogen jets for unintended releases involving high-pressure gas storage systems and fuel dispensers. For hydrogen jet flames, predictions of the radiative heat flux are shown and compared to exposure limits documented in the literature. For unignited hydrogen jets, concentration contours are presented and the distance to the lower flammability limit is computed. Predictions from the model are compared with experimental data and found to be in good agreement.