What is an explosion?

2016

This paper was presented at the Eleventh International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions (11 ISHPMIE) in Dalian on 24-29 July 2016. This paper explores a systematic methodology for validating, documenting and qualifying models used for consequence assessment of accidental explosion scenarios. To demonstrate the advantages of implementing and maintaining an integrated framework, example validation cases relevant for the modelling of vented hydrogen deflagrations are presented. Simulations were performed using the computational fluid dynamics (CFD) tool FLACS-Hydrogen. The main focus of this study is on the definition and application of a model evaluation protocol (MEP), building on recent advances from the hydrogen safety community. Particular emphasis is put on the classification of experiments in the validation database. The present methodology is found to be highly useful for qualifying a model system for specific applications as well as for...

2019

This paper is intended to be a brief survey of the state of the art about the safety aspects of industrial application using hydrogen. Although hydrogen has been used in the industry for a long time in chemistry, in metallurgy and more recently in the space industry and in electronics, new fields of application emerged at the turn of the century in the energy sector, broadening considerably both the technologies spectrum concerned but also the public exposed to the risks. Experts of the domain admit that the extent of the spreading of hydrogen technologies depends very much on the safety demonstration rendering the implementation acceptable to the public. Considerable effort was done along the two last decades both to develop risk assessment methods specific to hydrogen technologies and to understand better the key physical phenomena: material embrittlement, formation of explosive atmospheres, ignition, high pressure jet fires, unstable combustion, venting, etc. Major outcomes are r...

International Journal of Hydrogen Energy, 2017

Hydrogen fuels are being deployed around the world as an alternative to traditional petrol and battery technologies. As with all fuels, regulations, codes and standards are a necessary component of the safe deployment of hydrogen technologies. There has been a focused effort in the international hydrogen community to develop codes and standards based on strong scientific principles to accommodate the relatively rapid deployment of hydrogen-energy systems. The need for science-based codes and standards has revealed the need to advance our scientific understanding of hydrogen in engineering environments. This brief review describes research and development activities with emphasis on scientific advances that have aided the advancement of hydrogen regulations, codes and standards for hydrogen technologies in four key areas: (1) the physics of high-pressure hydrogen releases (called hydrogen behavior); (2) quantitative risk assessment; (3) hydrogen compatibility of materials; and (4) hydrogen fuel quality.

2011

The report describes the findings of a workshop that was held at the Institute for Energy and Transport (JRC) in Petten Netherlands, on the topic “Gap analysis of CFD modelling of hydrogen release and combustion”. The main topic was divided in 6 sub-topics: release and dispersion,auto-ignition, fires, deflagrations, detonations and DDT, and accident consequences. For each sub-topic, the main gaps in CFD modelling were identified and prioritised.Hydrogen is expected to play an important role in the energy mix of a future low carbon society, (the European Strategic Energy Technology Plan of the European Commission (COM 2007 - 723) and in the Hydrogen, Fuel Cells & Infrastructure Technologies Program-Multi-Year Research, Development, and Demonstration Plan of the USA Department of Energy (DoE 2007).Hydrogen safety issues must be addressed in order to ensure that the wide spread deployment and use of hydrogen and fuel cell technologies can occur with the same or lower level of hazardsan...

2010

2015

Hydrogen fuels are being deployed around the world as an alternative to traditional petrol and battery technologies. As with all fuels, regulations, codes and standards are a necessary component of the safe deployment of hydrogen technologies. There has been a focused effort in the international hydrogen community to develop codes and standards based on strong scientific principles to accommodate the relatively rapid deployment of hydrogen-energy systems. The need for science-based codes and standards has revealed the need to advance our scientific understanding of hydrogen in engineering environments. This brief review describes research and development activities with emphasis on scientific advances that have aided the advancement of hydrogen regulations, codes and standards for hydrogen technologies in four key areas: (1) the physics of high-pressure hydrogen releases (called hydrogen behavior); (2) quantitative risk assessment; (3) hydrogen compatibility of materials; and (4) hydrogen fuel quality.

2008

This paper is an attempt to give a concise overview of the state-of-the-art in the recent hydrogen safety research, mostly within the framework of activities performed by the European Network of Excellence HySafe “Safety of Hydrogen as an Energy Carrier” and related projects. The up-to-date knowledge, recent progress and future research are discussed in brief. The large eddy simulation (LES) model developed at the University of Ulster to simulate hydrogen releases and combustion is presented.

2015

International audienceSince a few years, hydrogen appears as a practical energy vector and some hydrogen applications are already on the market. However these applications are still considered dangerous, hazardous events like explosion could occur and some accidents, like the Hindenburg disaster, are still in the mind. Objectively, hydrogen ignites easily and explodes violently. Safety engineering has to be particularly strong and demonstrative; a method of precise identification of accidental scenarios (“probabilities”; “severity”) is developed in this article. This method, derived from ARAMIS method, permits to identify and to estimate the most relevant safety barriers and therefore helps future users choose appropriate safety strategies

Health and Safety Executive, 2020

Hydrogen storage is now, and will continue to be a key topic for established and developing applications moving forward. The main priorities identified for hydrogen storage are: 1 st priority: tank fire resistance (previously identified as a priority in 2016). 2 nd priority: non-destructive testing techniques for manufacturing and regular inspection. 3 rd priority: understanding the effects of tank overheating on the structural performance and lifetime of the tank (also highlighted as a key priority by session chair to underpin refuelling protocols). (4) Key Session Topic: ACCIDENT PHYSICS of GASEOUS HYDROGEN For the accident physics of gaseous hydrogen the top three priorities from a list of five are: 1 st priority: premixed combustion associated with large scale problems with obstacles, flame acceleration and particularly deflagration-detonation-transition (DDT). 2 nd priority: hydrogen venting. 3 rd priority: ignition statistical approaches and spontaneous ignition. These priorities are key to growing application inventories and preventing and understanding the consequences of accidental releases in these new and developing scenarios. (5) Key Session Topic: ACCIDENT PHYSICS of LIQUID HYDROGEN For the accident physics of liquid hydrogen the top three priorities from an extensive list of 15 are: 1 st priority: multi-phase accumulations with explosion potential. 2 nd priority: combustion properties of cold gas clouds, especially in congested areas. 3 rd priority: knowledge and experience related to releases of large quantities. Obviously, this is an highly important area with a number of outstanding issues, many of which are beginning to be addressed by international efforts, such as the FCH JU project PRESLHY or the Norwegian project SH2IFT. These efforts are essential, as LH2 is key to a number of applications, as noted with the strong overlap in priorities with aerospace and maritime, and others that will need larger hydrogen inventories and corresponding scaling-up of supply infrastructure. (6) Key Session Topic: MATERIALS The rapid development and deployment of hydrogen applications leads to an expectation that the materials that enable the novel use of hydrogen today must become the normal, common place and safe materials (or their equivalents) for tomorrow. To meet this expectation, it is essential that the characteristics and long term performance and reliability of materials across all applications is understood, evidenced, catalogued and applied. With this in mind, the materials prioritisation exercise is divided into two sub-chapters, as it was in 2016.

2021