Explosion Safety of hydrogen applications
Hydrogen applications can be assessed with Hazcalc, as well both for indoors and outdoor situations. Hydrogen applications, like compressors, tank facilities and pipe and ducting are mostly assessed as a normally closed and pressurized system.
Release rate of hydrogen
Therefore under step 2 of the assessment, type of release, the “pressurized” assessment must be selected. In step 3 “release assessment”, the possible release rate is automatically calculated, based on the differential pressure and the leak-size and other variables.
Ventilation and dillution
In step 4 the ventilation assessment has to be done. Typical for hydrogen, special attention is needed for assessing the background concentration, since the background concentration is an average concentration within the whole room under consideration. Hydrogen however, is very light and will move upward within a room and a ceiling layer can be formed. This can lead to a high concentration under the ceiling and this can create hazards.
So the background concentration, defined under the IEC 60079-10-1 standard, is not a good value to assess the dilution within a room. Another online tool must be used for assessing the possibility of ceiling formation. This can be done with HyRAM, a free online tool that can be used for, among other things, the assessment of layer formation under ceilings.
So with Hazcalc, the hazardous area, due to a jet release and its size can be assessed and in addition to that, with HyRAM the formation of a ceiling layer can be assessed. These two assessments together give a good way of assessing hydrogen releases for indoor and outdoor situations which will result in a specific hazardous area.
Within the (future) hydrogen economy, specific and more detailed standards will be developed e.g. for electrolyzers and fuel cells. For more specific advice or help with hydrogen assessments, feel free to contact us.