Dispersion and fire simulation storage tank using 3D CFD based software flacs

Several oil storage tanks implement an internal floating roof design. This design uses a fixed roof at the topmost of the structure and utilizes a floating roof that moves following the liquid level inside the tank. This combination intends to minimize vapor buildup inside the tank. However, the in-between roof’s space has a high probability of flammable gas accumulation. This gas may possess the critical risk of ignition in the presence of a heat source. Therefore, this research simulates the event when there is an ignition source inside and outside the tank. Indirect lightning, a heat source inside the tank, may occur at the edge of the floating roof, generating electric current. Meanwhile, direct lightning may hit the fixed roof from outside the tank, prompting the roof temperature to exceed the flashpoint and ignite. This research will present how much pressure is on the tank wall and roof with the volume tank containing flammable gas as a variable. The result shows that when the volume of flammable gas is high (low fuel level), it possibly burst through the roof. Considering pressure buildup in between the roof’s space, the outcome of this research can give an insight into designing a storage tank with two lids.