Final Activity Report Summary - HYFIRE (Hydrogen combustion in the context of fire and explosion safety)
The HYFIRE project offered a unique opportunity for 10 researchers in the early stages of their career to undergo rigorous scientific training and career development in the internationally renowned Centre for Fire and Explosion Studies (CFES) at Kingston University, with the support of the major international energy company British Petroleum (BP) and the United Kingdom Health and Safety Executive's Health and Safety Laboratory. The excellent training opportunities enabled the researchers to develop specific scientific skills and competencies in the diffusion, ignition and combustion of hydrogen within the context of fire and explosion safety.
HYFIRE looked at the cross-cutting safety issues related to the production, storage, transportation and utilisation of hydrogen. It used technical data from explosion experiments by BP and the Health and Safety Laboratory to develop advanced numerical tools for predicting spontaneous ignition, fire and explosions in hydrogen. The project focussed on cutting edge research in the following underpinning areas:
1. hydrogen jet flames from very high pressure release
2. spontaneous ignition of pressurised hydrogen
3. accidental release of liquid hydrogen jet flashing, evaporation, the subsequent dispersion and ignition potential
4. hydrogen combustion in semi-confined and vented geometries and the conditions for deflagration to detonation (DDT) processes
5. detonation of hydrogen and vapour cloud
6. hazards' analysis of small hydrogen leaks in enclosures with limited ventilation
7. flame and wall interaction in hydrogen and hydrocarbon combustion
8. combustion and flammability of hydrogen doped hydrocarbon fuels
9. structure response to blast loading.
HYFIRE researchers successfully developed and validated advanced computational fluid dynamics (CFD) models for the spontaneous ignition phenomenon in pressurised hydrogen release. While hydrogen fuel cell powered vehicles were on the way to commercial application, this phenomenon was of important safety concern. With the developed numerical tool, HYFIRE researchers conducted further parametric studies to illustrate that the release pressure, the length of the release tube, the finite rupture process of the initial pressure boundary and the surrounding obstacles all played important roles in the occurrence of spontaneous ignition.
HYFIRE researchers also developed advanced CFD models to predict conditions that could lead to detonation in confined explosions, i.e. in explosion inside and enclosure with some obstacles, or semi-confined explosions, which could take place in a car park with limited openings. The development was carried out within the frame of Openfoam, an open source CFD code, to facilitate wide applications and exploitation. Numerical simulations were conducted for hydrogen explosions in a refuelling environment and in a model storage room. Following this, detonation modelling was carried out for pancake and spherical clouds.
The predictions demonstrated a sharp fall of overpressure at the edge of the cloud. In contrary to common belief that the impulse of all explosions would push objects away from the epicentre, the predictions revealed the existence of high negative drag impulse within the detonated cloud. Such an impulse was also found to vary with heights. The findings from the present analysis were in line with the forensic evidence on damages in some historic accidents such as the Buncefield incident, in which localised transition to detonation occurred and challenged the analysis of a previous accident in which forensic evidence suggested localised detonation but was considered as the consequence of fire storms.
Four years on, some of the researchers employed during the early stages of the project had already moved on to successful careers in the industry with Ford, IAV U.K. Limited, AREVA NP, CD-adapco etc., while some were continuing their research at CFES for the degree of PhD with further funding from others sources.
HYFIRE looked at the cross-cutting safety issues related to the production, storage, transportation and utilisation of hydrogen. It used technical data from explosion experiments by BP and the Health and Safety Laboratory to develop advanced numerical tools for predicting spontaneous ignition, fire and explosions in hydrogen. The project focussed on cutting edge research in the following underpinning areas:
1. hydrogen jet flames from very high pressure release
2. spontaneous ignition of pressurised hydrogen
3. accidental release of liquid hydrogen jet flashing, evaporation, the subsequent dispersion and ignition potential
4. hydrogen combustion in semi-confined and vented geometries and the conditions for deflagration to detonation (DDT) processes
5. detonation of hydrogen and vapour cloud
6. hazards' analysis of small hydrogen leaks in enclosures with limited ventilation
7. flame and wall interaction in hydrogen and hydrocarbon combustion
8. combustion and flammability of hydrogen doped hydrocarbon fuels
9. structure response to blast loading.
HYFIRE researchers successfully developed and validated advanced computational fluid dynamics (CFD) models for the spontaneous ignition phenomenon in pressurised hydrogen release. While hydrogen fuel cell powered vehicles were on the way to commercial application, this phenomenon was of important safety concern. With the developed numerical tool, HYFIRE researchers conducted further parametric studies to illustrate that the release pressure, the length of the release tube, the finite rupture process of the initial pressure boundary and the surrounding obstacles all played important roles in the occurrence of spontaneous ignition.
HYFIRE researchers also developed advanced CFD models to predict conditions that could lead to detonation in confined explosions, i.e. in explosion inside and enclosure with some obstacles, or semi-confined explosions, which could take place in a car park with limited openings. The development was carried out within the frame of Openfoam, an open source CFD code, to facilitate wide applications and exploitation. Numerical simulations were conducted for hydrogen explosions in a refuelling environment and in a model storage room. Following this, detonation modelling was carried out for pancake and spherical clouds.
The predictions demonstrated a sharp fall of overpressure at the edge of the cloud. In contrary to common belief that the impulse of all explosions would push objects away from the epicentre, the predictions revealed the existence of high negative drag impulse within the detonated cloud. Such an impulse was also found to vary with heights. The findings from the present analysis were in line with the forensic evidence on damages in some historic accidents such as the Buncefield incident, in which localised transition to detonation occurred and challenged the analysis of a previous accident in which forensic evidence suggested localised detonation but was considered as the consequence of fire storms.
Four years on, some of the researchers employed during the early stages of the project had already moved on to successful careers in the industry with Ford, IAV U.K. Limited, AREVA NP, CD-adapco etc., while some were continuing their research at CFES for the degree of PhD with further funding from others sources.