Safety of hydrogen/natural gas mixtures by pipelines : ANR french project HYDROMEL

International audienceIn order to gain a better understanding of hazards linked with Hydrogen/Natural gas mixtures transport by pipeline, the National Institute of Industrial Environment and Risks (INERIS) alongside with the Atomic Energy Commission (CEA), the industrial companies Air Liquide and GDF SUEZ, and the French Research Institutes ICARE and PPRIME (CNRS) have been involved in a project called HYDROMEL. This project was partially funded by the French National Research Agency (ANR) in the framework of its PAN-H program aimed at promoting the R&D activities related to the hydrogen deployment. Firstly, the project partners investigated how a NG/H2 mixture may influence the modeling of a hazard scenario, i.e. how the addition of a quantity of hydrogen in natural gas can increase the potential of danger. Therefore it was necessary to build an experimental database of physics properties for mixtures. Secondly, effect distances in accidental scenarios that could happen on pipelines have been calculated with existing models adapted to the mixtures. This part was preceded by a benchmark exercise between all partners' models and experimental results found in the literature. Finally the consortium wrote a 'good practice guideline for modeling the effects related to the release of natural gas /hydrogen mixture'. The selected models and their comparison with data collected in the literature as well as the experimental results of this project, and the main conclusions of the guidelines are presented in this paper

Development of engineering tools for hydrogen risk assessment

La présente communication vise à décrire les différents outils développés par la R&D Air Liquide en réponse à un besoin des opérationnels quant à la disponibilité d’outils de calcul simples, précis et rapides aussi bien pour le dimensionnement d’applications que pour l’évaluation des risques et conséquences des activités industrielles en lien avec l’hydrogène. La méthodologie pour parvenir aux outils finaux répondant aux attentes des utilisateurs, de profil et d’activité variés, est présentée, ainsi que les approches analytiques sélectionnées.This communication aims at describing the different engineering tools developed by Air Liquide R&D to bring to operational simple, accurate and fast calculation tools, both for the design of applications and for risks and consequences assessment of industrial activities related to hydrogen. The methodology and the selected analytical approaches to build final tools answering to end-users expectations, with varied profiles and activities, are presented

Etude expérimentale et modélisation de l'oxydation d'hydrocarbures légers

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Study of potential leakage on several stressed fittings for hydrogen pressures up to 700 bar

International audienceIn order to improve risk analyses and influence the design of the future H2 systems, an experimental study on 'real' leaks qualification and quantification was performed. In H2 energy applications, fittings appeared as a significant leakage potential and subsequently explosion and flame hazards. Thus, as a part of the 'Horizon Hydrogene Energie' French program, four kinds of commercial fittings usually employed on H2 systems were tested thanks to a new high pressure test bench - designed, setup and operated by INERIS - allowing experiments to be led for H2 pressures until 700 bar. The fittings underwent defined stresses representative of H2 systems lifetime and beyond. The associated leaks - when existing - are characterized in terms of flow rate

Potential for Hydrogen DDT with Ambient Vaporizers

PresentationThe ignition of a hydrogen-air mixture that has engulfed a typical set of ambient vaporizers (i.e., an array of finned tubes) may result in a deflagration-to-detonation transition (DDT). Simplified curve-based vapor cloud explosion (VCE) blast load prediction methods, such as the Baker- Strehlow-Tang (BST) method, would predict a DDT given that typical ambient vaporizers would be rated as medium or high congestion and hydrogen is a high reactivity fuel (i.e., high laminar burning velocity). Computational fluid dynamic (CFD) analysis of a single vaporizer of typical construction was carried out using the FLACS code to evaluate the potential for a DDT with a vaporizer engulfed by a hydrogen-air mixture at the worst-case concentration. This analysis showed that while significant flame acceleration occurs within the vaporizer, as expected, a DDT is not predicted. However, the analysis did indicate that a DDT may occur for two or more closely spaced vaporizers. This is relevant since multiple vaporizers are frequently present at industrial installations and are typically placed closely together to limit the required area. Spacing adjacent vaporizers further apart could preclude a DDT. However, specification of the spacing to preclude a DDT would require refined CFD analysis and/or testing, neither of which has been performed at this time. This paper also discusses the application of simplified VCE blast load methods to ambient vaporizers engulfed in a flammable hydrogen-air cloud in order to illustrate the impact of a DDT

Benchmark exercises related to the safety analysis of hydrogen / natural gas mixture transportation in pipelines

International audienc