< e-Platform

Training Materials

There is a threefold approach to training in HyResponder: educational training, operational training and virtual reality training. All elements form part of a training package and underpin the EERG. Supporting materials for each of these elements can be found on this Platform.


ACH Air change per hourALARP As low as reasonably possible
APU Auxiliary power unitBEV Battery electric vehicle
BLEVE Boiling liquid expanding vapour explosionCCTV Closed-circuit television
CEP Clean energy partnershipCFD Computational fluid dynamics
CFRP Carbon fibre reinforced plasticCGH2 Hydrogen stored as compressed gas
CHP Combined heat and powerCNG Compressed natural gas
CVR Cockpit voice recorderDCS Distributed control system
DDT Deflagration-to-detonation transitionDIC Driver’s information centre
DOE Department of energy of the USEIGA European industrial gases association
EMSA European maritime safety organizationELT Emergency locator transmitter
ESD Emergency shut-down deviceFCH Fuel cell and hydrogen
FC Fuel cellFCEV Fuel cell electric vehicle
FCTO Fuel cell technologies officeFCV Fuel cell vehicle
FDR Flight data recorderFED Field effect gas detectors
FRP Fibre-reinforced polymer/plasticGH2 Gaseous hydrogen
GHG Greenhouse gasGSE Ground support equipment
GTR Global technical regulationsHAZOP Hazard and operability study
HE Hydrogen embrittlementHEM Homogeneous equilibrium
HFM Homogeneous frozenHGV Heavy goods vehicle
HNEM Homogeneous non-equilibrium flash modelHPV Hydrogen-powered vehicle
HRR Heat release rateHRS Hydrogen refuelling station
HSE Hydrogen safety engineeringHSL Health and safety laboratory
HTI Heat transfer indexHTS High-temperature shift
ICE Internal combustion engineIMO International maritime organization
IR InfraredJIVE Joint initiative for hydrogen vehicles across Europe
KIT Karlsruhe institute of technologyKHI Kawasaki heavy industries
KSC Kennedy space centreLDL Lower detonation limit
LES Large eddy simulationLFL Lower flammability limit
LH2 Liquified hydrogenLHRS Liquid hydrogen refuelling station
LLNL Lawrence Livermore national laboratoryLNB Leak-no-burst
LNG Liquid nature gasLPG Liquid petroleum gas
MEA Membrane electrode assembly MEMS Micro electro mechanic system
MIE Minimum ignition energy MLI Multi-layer insulation
NBP Normal boiling pointNP Neutral plane
NTP Normal temperature and pressureNWP Normal working pressure
PEM Proton exchange membrane PPE Personal protective equipment
PPP Pressure peaking phenomenonPRD Pressure relief device
PRT Rapid phase transitionPRV Pressure relief valve
PSV Pressure safety valve QDR Qualitative design review
QRA Quantitative risk assessmentRANS Reynolds-averaged Navier-Stokes
RCS Regulations, codes and standardsRHTI Radiative heat transfer indices
RMPP Risk management prevention plan SCC Stress corrosion cracking
SD Separation distance SDO Standard development organisation
SLH2 Slush hydrogen SIL Safety integrity level
SMR Steam methane reforming/reformerSNL Sandia National Laboratory
SOFC Solid oxide fuel cellSS Stainless steel
STP Standard temperature and pressureSUV Sport utility vehicle
TCO Total cost of ownershipTDU Thermal dose unit
TPL Thermal protection layer TPRD Thermal-activated pressure relief device
TRL Technology readiness levelTSS Technical sub-systems
UAV Unmanned aerial vehicleUDL Upper detonation limit
UFL Upper flammability limit UV Ultraviolet
UVCE Unconfined vapour cloud explosionVCE Vapour cloud explosion
ZND Zeldovich, von Neumann and Doring model

You can find the glossary in the PDF format here.

  • Acceptance criteria are the terms of reference, against which safe design of a FCH facility/infrastructure is assessed.
  • Ambient pressure cycling test is a test for hydrogen tanks not failing before reaching 11,250 fill cycles (representing a 15-year life of use in commercial heavy-duty vehicles).
  • Auto-ignition temperature is the minimum temperature required to initiate the combustion reaction of fuel-oxidiser mixture in the absence of an external source of ignition.
  • Blow-down is a process where the storage pressure decreases with time during a leak.
  • Blow-off is the flame extinguishment at a high velocity without a lift-off.
  • Blow-out is the flame extinguishment at high velocity with a lift-off.
  • Blow-out limit is a fuel flow velocity limit beyond which a lifted flame blows out.
  • Bonfire test is a test for the tank venting through the non-reclosing TPRD and not failing when exposed to a bonfire of 20 minutes duration.
  • Brush discharge is a discharge between a charged insulator and a conducting earthed point.
  • Catastrophic rupture is that gaseous hydrogen from a high-pressure storage container before its walls are weakened by high temperatures.
  • Cell size is the parameter that characterises the detonation sensitivity of a hydrogen-air mixture.
  • Corona discharge is a silent, usually continuous, discharge with a current but without a plasma channel.
  • Deflagration is a term to describe ‘to burn down’, which is subsonic combustion propagating through heat transfer; hot burning material heats the next layer of cold material and ignites it.Itis the process following the weak ignition in a combustible mixture, which propagates at a subsonic speed into fresh, unburned mixture.
  • Detonation is the phenomenon of combustion zone propagating at the velocity higher than the speed of sound (supersonic) in the unreacted mixture. It is the worst case of accidental hydrogen combustion.
  • Drop-back is the reattachment to the nozzle of a lifted flame by a decrease of lift-off velocity.
  • Effective diameter is the jet diameter at the location where expansion down to 1 bar takes place, in an under-expanded jet.
  • Expanded jet is the jet with a pressure at the nozzle exit equal to atmospheric pressure.
  • Expansion coefficient is the ratio of the unburnt mixture density to the density of combustion products at the same pressure.
  • Fire-resistance rating is a measure of time for which a passive fire protection system can withstand a standard fire resistance test.
  • Flame lift-off is the condition, in which the flame and a burner become separated.
  • Flame speed is the velocity of the flame with the respect to a fixed observer.
  • Flammability range is the range of concentrations between the lower and the upper flammability limits. The lower flammability limit(LFL) is the lowest concentration, and the upper flammability limit (UFL) is the highest concentration of a combustible substance in a gaseous oxidizer that will propagate a flame.
  • Flashing is a process occurs when LH2 at a high pressure is transferred from trucks and rail cars to a low-pressure vessel.
  • Flashpoint is the lowest temperature, at which the fuel produces enough vapours to form a flammable mixture with air at its surface.
  • Froude number (Fr) is the dimensionless number equal to the ratio of inertial to gravity force.
  • Hazard distance is the minimum distance, which separates “specific targets (e.g. people, structures or equipment) from the consequences of potential accidents related to the operation a hydrogen facility”.
  • Hydrostatic burst test is a test for tank burst, for which the pressure typically more than 2.25 times of the working pressure.
  • Incapacitation is a condition, under which humans do not function adequately and unable to escape untenable conditions.
  • Laminar burning velocity is the rate of flame propagation relative to the velocity of the unburnt gas that is ahead of it, under stated conditions of composition, temperature, and pressure of the unburned gas.
  • Leading point is the leading edge of flame front, typically a flamelet structure, which is responsible for the propagation of flame.
  • Leak-before-break test is the test for the tank failing by leakage or shall exceed the number of filling cycles.
  • Lift-off height is the height from the nozzle exit to the base of a lifted flame.
  • Lift-off velocity is the fuel flow velocity causing a flame to be detached from the nozzle.
  • Mach number is the dimensionless number equal to the ratio of the local flow velocity to the local speed of sound.
  • Maximum experimental safe gap of flammable gases and vapours is the lowest value of the safe gap measured, according to IEC 60079-1- 1 (2002), by varying the composition of the mixture.
  • Maximum allowable working pressure (MAWP) is the maximum pressure, to which any component or portion of the pressure system can be subjected over the entire range of design temperatures [5].
  • Minimum Ignition Energy (MIE) of flammable gases and vapours is the minimum value of the electric energy, stored in the discharge circuit with as small a loss in the leads as possible, which (upon discharge across a spark gap) just ignites the quiescent mixture in the most ignitable composition.
  • Normal temperature and pressure (NTP) conditions are temperature of 293.15 K and pressure of 101.325 kPa.
  • Nominal working pressure is a gauge pressure, which characterises typical operation of a system.
  • Non-premixed flame (often called a diffusion flame) is the flame, in which the oxidiser and the fuel are not mixed prior to reaching a flame front. During combustion oxidiser combines with a fuel by diffusion. The flame speed is limited by the rate of diffusion.
  • Occupants are people present within the boundaries of a FCH facility/infrastructure including personnel involved in its operation and maintenance as well as the customers/visitors.
  • Ortho-para-hydrogen conversion is the conversion of hydrogen between ortho-to para-hydrogen.
  • Overpressure is the pressure in a blast wave above the atmospheric pressure, or the pressure within a containment structure that exceeds the maximum allowable working pressure of the containment structure.
  • Permeation is the movement of atoms, molecules, or ions into or through a porous or permeable substance.
  • Penetration test is the test for the tank not rupturing when an armour piercing bullet or an impactor with a diameter of 7.62 mm or greater fully penetrates its wall.
  • Place of safety is a predetermined place inside or outside an FCH facility/infrastructure, in which persons are not in immediate danger from the effect of hydrogen release, fire or explosion.
  • Premixed flame is the flame, in which the oxidiser has been mixed with the fuel prior to the reaching the flame front. Combustion of premixed fuel and oxidiser forms a thin flame front due to the reactants being readily available.
  • Public are people present outside the boundaries of an FCH facility/infrastructure.
  • Quenching distance is the maximum distance between two parallel plates that will extinguish a flame passing between them. The quenching distance decreases with the pressure and temperature increase. It also depends on the mixture composition.
  • Quenching gap is the spark gap between two flat parallel-plate electrodes at which ignition of combustible fuel-air mixtures is suppressed. The quenching gap is the passage gap dimension requirement to prevent propagation of an open flame through a flammable fuel-air mixture that fills the passage.
  • Rarefaction wave is also called a relief wave, an unloading wave, and a Taylor wave. It is the progression of particles being accelerated away from a compressed or shocked zone. It travels in the direction opposite to the acceleration of the particles.
  • Residual thermal leak is the heat leakage loss proportional to the ratio of surface area to the volume of the storage vessel.
  • Reynolds number (Re) is the dimensionless number that gives a measure of the ratio of inertial to viscous forces.
  • Sensitive area is the establishment, infrastructure or equipment containing inventories of dangerous substances that can become a source of harm when targeted by a hydrogen incident/accident.
  • Sloshing is a motion of LH2 in a vessel due to acceleration or deceleration, which occurs during its transportation by tankers. Some of the impact energy of the liquid against the vessel is converted to thermal energy.
  • Spark discharge is a single plasma channel between a high potential conductor and an earthed conductor.
  • Survivability is the maximum exposure that may be received with a negligible statistical probability of fatality/damage and without impairment of an individual’s ability to escape.
  • Tenability is the maximum exposure to hazards from a hydrogen incident/accident that can be tolerated without violating safety goals.
  • Threshold is the maximum intensity or dose for a given hazard that corresponds to a specific physiological (for humans) or structural (for structures and equipment) response.
  • Throttled expansion is to describe the majority of gases are usually cooled when expanded from high to low pressure through a porous plug, a small aperture or a nozzle.
  • Under-expanded jet is a jet with a pressure at the nozzle exit above the atmospheric pressure.
  • Under-ventilated fire is characterised by relatively high hydrogen release rate when oxygen is consumed at a faster rate than it can be replenished through the ventilation. In the case where there is insufficient ventilation the flame will be ventilation-controlled.
  • Visible flame length is the centerline distance from the tip of the nozzle to the flame end.
  • Well-ventilated fire is characterized by a relatively low hydrogen release rate and complete combustion of hydrogen within the enclosure.