Hydrogen release at a public hydrogen refuelling station.

A leak occurred at a compressor of a hydrogen refuelling station, Rescue services were alerted and the station's activity is interrupted. The leak was stopped by closing valves.

The station had a storage system consisting of ten cryogenic tanks for a total of 6,000 litres of liquid hydrogen.The filling of FCEV was occurring via a high-pressure hydrogen tank fed by a compressor bringing the 4 bar hydrogen from the liquid hydrogen storage tanks up to the 380 bar.
Just before the leak, a vehicle fill had depleted the compressed hydrogen tank. Therefore, the compressor turned on to refill the storage. After running about 2 hours, a crankshaft bearing started to fail. This allowed greater movement of the shaft, which led to a shaft seal leaking hydrogen. The compressor shut down on low suction pressure and then the system was shut down using the e-stop by the emergency responders.

INITIATING cause was a deterioration of a component of a hydrogen compressor.

hydrogen refuelling station, liquid hydrogen storage, hydrogen compressor, bearing

A vehicle had just refuelled, causing the need to top up the high pressure storage tank.

No consequence.

The compressor stopped on suction low pressure signal.

According to the H2Tools report (see references), the corrective action consisted in adding a gas detector in close proximity to the compressor shaft. Preventing measure to predict bearing failure were also considered, such as a vibration switch.

In addition, the manufacturer was contacted and the bearing design analysed for possible improvements).