284130 Investigation of Hydrogen Gas Safety for the Electrolysis Based Ballast Tank Treatment System
Ballast water has been identified as a serious risk to marine environment and a major cause of ecological disturbance due to the pathogens and harmful adventive species discharged through ballast water. The International Maritime Organization (IMO) promulgates the international guidelines containing regulations about technical standards and requirements for ballast water management in order to control adventive species in the discharges. A number of techniques are developed to diminish the aquatic invasive species in ballast water and sedimentations, electrolysis coupled treatment system shows advantages in disinfection efficiency for target species and simple installation and maintenance of system. Simultaneously, the explosion risk of hydrogen gas generated through electrolysis system is issued in terms of safety of the ship. The main aim of this study is to verify dynamic behavior of ballast water and concentrations of hydrogen gas in the ballast tank during ballasting process. Computational fluid dynamic (CFD) simulations were implemented to analyze multiphase behavior of hydrogen gas and ballast water within the ballast tank. Hydrogen gas concentration at vent pipe is also measured to verify CFD simulation model. Consequently, hydrogen gas is released into vent pipe normally at 200 ppm, and ballast water contains 0.3 ppm of hydrogen in average. Based on the analysis, we analyze that hydrogen explosion is highly unlikely in the ballast tank. Finally, a recommendation on operationally feasible ways for sustaining hydrogen safety against potential explosion is suggested.
Figure SEQ Figure \* ARABIC 1. Hydrogen gas concentration profile
Figure SEQ Figure \* ARABIC 2. Volume fraction of sea water
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