CFD Based Simulation of LNG Release during Bunkering and Cargo Loading/Unloading Simultaneous Operations of a Containership

Abstract

In order to reduce waiting time in port for large LNG fueled ships, it is suggested that LNG ship-to-ship (STS) bunkering and cargo loading/unloading should be car- ried out simultaneously. This study investigated the safety zone of a LNG bunkering vessel with 10,000 cubic meters capacity transferring LNG fuel to a LNG fueled 18000TEU containership. Four LNG leakage scenarios were identified based on failure frequencies analysis of piping systems and severity of consequence. The three-dimensional CFD software FLACS was adopted to calculate flammable cloud dispersion after LNG leakage. As a result, we obtained a rectangular danger zone; the domain outside of this zone can be considered as safe. The danger zone of LNG STS bunkering and cargo loading/unloading simultaneous operations (SI- MOPS) varies with different results for different designs and operation locations. Due to high frequencies and severe consequences involved, two typical scenarios cannot be ignored in similar studies: the leakage of an LNG hose and natural gas release from a bunkering tank’s safety relief valve during bunkering. INTRODUCTION