For maintenance and repair work, hydrogen-bearing systems have to be taken out of operation and then put back into operation. Up to now, this has been very time-consuming, and depressurising and flushing the storage tanks in particular consumes a lot of nitrogen (N2) and hydrogen (H2). In the new LHYVE-Cycle project, a new type of flushing unit for hydrogen tanks is now being developed with an innovative simulation and AI-supported concept. This should make the commissioning and decommissioning of hydrogen systems safer and faster and consume less gas.
During decommissioning, the hydrogen in the tank is displaced with nitrogen until its concentration is safely below the explosion limit. During (re)commissioning, oxygen from the ambient air in newly installed or opened storage tanks must first be removed with nitrogen before the tank can be filled with hydrogen. To meet quality specifications, the nitrogen must be completely removed from the tank by purging with hydrogen.
Until now, these steps have been carried out using manually controlled pressure change cycles, which are based on highly simplified assumptions, are hardly monitored or checked and consume large quantities of gas – with limited process reliability and reproducibility at the same time.