CFD analysis of the influence of a perimeter wall on the natural gas dispersion from an LNG pool

We developed an innovative tool to support the simulation of gas dispersion from liquefied natural gas pools in presence of obstacles. For the first time, the systematic evaluation of the influence of atmospheric stability conditions and the variation of the source term on congested dispersion scenarios is carried out, coupling integral models and computational fluid dynamics (CFD). The atmospheric boundary layer is implemented in the CFD together with ad-hoc boundary conditions, aimed at reproducing the dynamic pool spreading and consequent vaporization, simulated through integral models. A preliminary comparison is done between the results given by CFD and literature integral dispersion models in an open field case; subsequently, the presence of a perimeter wall is analyzed through the CFD technique. The results show a good agreement between the CFD and the integral models in the open field configuration, even though an overprediction of methane concentration is underlined for the integral model. In the case of the obstacle, CFD permits a precise analysis of the flow-field in all the considered atmospheric conditions and a deep investigation of the effects of the wall on the methane concentration.