Computational Fluid Dynamics (CFD) is a consolidated tool to support industrial projects development and was recently adopted in the framework of consequence assessment and safety analyses. In the present study, a CFD model of pressurized vessels exposed to an accidental fire was developed, with the aim to determine the transient behavior of the stored fluid during the heat-up. An integral model for consequence assessment was adopted in order to set advanced boundary conditions to the CFD model. The results of CFD simulations allowed predicting temperature and velocity of both liquid and vapor phases, as well as the complex recirculation phenomena induced by natural convection. This allowed determining the pressurization rate in the fired t...