Sloshing Measurements inside a Liquid Hydrogen Tank with External-Heating-Type MgB(2) Level Sensors during Marine Transportation by the Training Ship Fukae-Maru

Recently, a project was initiated in Japan to transport a large amount of liquid hydrogen (LH(2)) from Australia to Japan by sea. It is important to understand the sloshing and boil-off that are likely to occur inside an LH(2) tank during marine transportation by ship, but such characteristics are yet to be experimentally clarified. To do so, we combined the liquid level detected by five 500 mm long external-heating-type magnesium diboride (MgB(2)) level sensors with synchronous measurements of temperature, pressure, ship motion, and acceleration during a zigzag maneuver. During this zigzag maneuver, the pressure of gaseous hydrogen (GH(2)) in the small LH(2) tank increased to roughly 0.67 MPaG/h, and the temperature of the GH(2) in the small LH(2) tank increased at the position of gaseous hydrogen at roughly 1.0 K/min when the maximum rolling angle was 5°; the average rolling and liquid-oscillation periods were 114 and 118 s, respectively, as detected by the MgB(2) level sensors, which therefore detected a long-period LH(2) wave due to the ship’s motion.