Sloshing Measurements inside a Liquid Hydrogen Tank with External-Heating-Type MgB2 Level Sensors during Marine Transportation by the Training Ship Fukae-Maru

Abstract

Recently, a project was initiated in Japan to transport a large amount of liquid hydrogen (LH2) from Australia to Japan by sea. It is important to understand the sloshing and boil-off that are likely to occur inside an LH2 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 (MgB2) 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 (GH2) in the small LH2 tank increased to roughly 0.67 MPaG/h, and the temperature of the GH2 in the small LH2 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 MgB2 level sensors, which therefore detected a long-period LH2 wave due to the ship’s motion.

Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities

“…In addition to selecting suitable materials for tank design, and minimising boil-off gas during transportation, 92,304 another key consideration in liquid hydrogen transport is sloshing. 304 This phenomenon is the movement of the liquid in the vessel due to the motion of the carrier, and it can lead to significant boil-off. Baffles may be installed in the tank to mitigate the effect.…”

An Extensive Review of Liquid Hydrogen in Transportation with Focus on the Maritime Sector

“…The authors concluded that the increase rate of LH 2 temperature and tank pressure was large if the ship rolling angle was six degrees [125]. In 2018, Maekawa et al [146] used a similar setup always installed on the Fukae-Maru vessel to investigate the LH 2 temperature and pressure increase rates as well as the LH 2 sloshing within the tank during a zigzag maneuver. Measurements inside the LH 2 tank are very challenging due to the ultra-low temperature effect.…”

Modelling of Boil-Off and Sloshing Relevant to Future Liquid Hydrogen Carriers

“…The thermodynamic effects of sloshing in LH2 ships are also not widely investigated. Maekawa et al (2017) [30] and Maekawa et al (2018) [31] observed liquid level and temperature measurements for 0.02 m 3 of LH2 in a test ship subjected to manoeuvreinduced sloshing in several planes of motion. Wei et al [32] further investigated sloshinginduced pressure changes in the specific case of a tank filled with LH2.…”