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.
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.
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 a very small molecule and will dilute very rapidly with air. For indoor releases a ventilation efficiency factor of 1 could be suggested. This means that the maximum concentration within the room under consideration will be calculated based on the volumetric release rate divided by the fresh air ventilation capacity.
Bases on these input parameters, the hazardous area can be classified easily with Hazcalc. Also the minimum needed ventilation capacity can be calculated in order to have a non-hazardous area or a zone 2 or 1 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.
