Study on boiling behavior of pressurized liquid nitrogen under rapid depressurization

Abstract

A project to transport a large amount of liquid hydrogen (LH2) from Australia to Japan by a cargo carrier is underway. In case of unloading LH2 from the tank on board to that on land, the pressure of the tank on board should be reduced promptly. However, an optimal depressurization speed to reduce the pressure before unloading LH2 has not yet been studied. As preliminary studies on boiling behavior of pressurized liquid nitrogen (LN2) instead of LH2, transitions of temperature distribution and pressure inside a small tank as well as evaporation rate under rapid depressurization have been measured simultaneously. Experimental results are discussed with parameters of setting pressure, depressurization speed and liquid condition. © Published under licence by IOP Publishing Ltd.