Numerical study of transient natural convection in a pressurized LNG storage tank

Transient natural convection in a pressurized LNG storage tank is investigated numerically by solving the conservation equations of mass, momentum and energy with a commercial CFD code, FLUENT. The generation rate of boil-off-gas (BOG) vaporizing from the liquid is predicted from the heat balance at the liquid-vapor interface. As one of the methods to reduce the BOG, we investigate a pressurization of storage tank. The present numerical results show that the BOG generation pattern strongly depends on the vertical temperature distribution, which is affected by the increased tank pressure. The effects of tank pressure, tank size and pressurization procedure on the BOG generation pattern are quantified.