Hydrogen is expected to play an important role in the energy mix of a future lowcarbonsociety, as it is stated in the European Strategic Energy Technology Plan ofthe European Commission (COM 2007 - 723) and in the Hydrogen, Fuel Cells &Infrastructure Technologies Program-Multi-Year Research, Development, andDemonstration Plan of the USA Department of Energy (DoE 2007).Hydrogen safety issues have to be addressed in order to demonstrate that the widespread deployment and use of hydrogen and fuel cell technologies can occur withthe same or lower level of hazards and associated risk compared to theconventional fossil fuel technologies. Computational Fluid Dynamics (CFD) isconsidered one of the tools to investigate safety issues related to the production,storage, delivery and use of hydrogen. CFD techniques can provide a wealthyamount of information on the dynamics of hypothetical hydrogen accident and itsconsequences. The CFD-based consequence analysis is then used in riskassessments. In this context a workshop was organised at the Institute for Energy(JRC) in Petten, Netherlands with the purpose of identifying the gaps and issues inCFD modelling of hydrogen release and combustion. The report describes themain findings of the workshop.A hydrogen accident occurs usually following a typical sequence of events: anunintended release, the mixing of hydrogen with air to form a flammable mixture,the ignition of the flammable cloud and depending on the conditions, a fire or anexplosion (deflagration or/and detonation). For each stages of the accident, thecritical CFD issues have been identified and prioritised.Beyond the specific issues of CFD modelling that are described for each accidentstage in the report, some general modelling issues can be found in all stages:• lack of an extensive validation of CFD codes/models that covers all therelevant range of conditions that can be found in hypothetical accidentscenarios e.g. in terms of geometrical lay-out, leak flow rates, etc.• lack of a CFD validation protocol for hydrogen like it exists for LiquefiedNatural Gas (LNG): the Model Evaluation Protocols (MEP) for assessmentof models for accident consequences, with guidance on evaluating models interms of scientific assessment, verification and validation.• lack of a database of experiments for validation of hydrogen models.• in some cases, lack of complete and accurate experimental data for the CFDvalidation.
|Publisher||Publications Office of the European Union|
|Number of pages||60|
|Publication status||Published - 2010|