Pressure recovery during pressure reduction experiment with large-scale liquid hydrogen tank

The world's first Liquefied Hydrogen (LH2) Carrier which will transport LH2 from Australia to Japan has been built. At Japanese port, reducing the tank pressure be required for safe operation. However, reduction cause flashing, leading an excess of venting capacity or liquid leakage. Hence, purpose this research is clarify rate and behavior through experimental numerical approaches respectively. Pressure experiment under high level condition was conducted by using 30 m3 filled with saturated LH2. showed that recovery occurred at beginning depressurization, then decreased based on equilibrium state. From analysis VOF in-house CFD code, it found caused boiling delay, followed saturation after fully stirred.