CFD modeling of LPG vessels under fire exposure conditions

Abstract

Fire exposure of tanks used for the storage and transportation of liquefied gases under pressure may cause complex heat- and mass-transfer phenomena that may contribute to compromise the integrity of the vessels in accident scenarios. Heat transfer through vessel lading results in the heat-up of the internal fluid and the increase of vessel internal pressure. However, local temperature gradients in the liquid phase cause liquid stratification phenomena that result in a more rapid vaporization and pressure build-up in the liquid phase. These fundamental phenomena were analyzed by a computational fluid dynamic model. The model was specifically focused on the early steps of vessel heat-up, when liquid stratification plays a relevant role in determining the vessel internal pressure. A two-dimensional transient simulation was set up using ANSYS FLUENT in order to predict the evolution of the liquid and vapor phases during the tank heat up. The model was validated against large scale experimental data available for liquefied petroleum gas vessels exposed to hydrocarbon fires, and was applied to case studies derived from recent accidental events in order to assess the expected time of pressure build-up in different fire scenarios

Coupling of integral methods and CFD for modeling complex industrial accidents

“…This is one of the main improvements with respect to other works in literature (Bi et al (2011) is known a priori, in order avoid any convergence problems due to the evaporation/condensation phenomena. In other approaches, the domain is divided into two sub-domains, one for the liquid and one for the vapor phase, as done by D'Aulisa et al (2014). In such a manner the grid can be coarse, with a significant saving of CPU time; however the change of liquid level due heat-up cannot be predicted effectively.…”

“…Shi et al (2013), D'Aulisa et al (2014 and references therein). Hence the vapor at the interface is saturated at the temperature of the warmest liquid layer.…”

DAMS: A Model to Assess Domino Effects by Using Agent‐Based Modeling and Simulation

“…In fact, several studies pointed out the complicating physical phenomena associated with equipment exposed to fire, overpressure, and missile projection . Specific advanced model tools such as finite elements modeling or computational fluid dynamics may be required for a comprehensive detailed assessment. Nevertheless, previous research was dedicated to the development of simplified approaches aimed at reproducing the behavior of target equipment exposed to a given escalation vector.…”

Experimental and numerical study of the behavior of LPG tanks exposed to wildland fires

“…In recent years, more detailed models for the simulation of LPG vessels exposed to fire were developed, based on computational fluid dynamics (CFD). However, in the studies presented by (Bi et al, 2011;D'Aulisa et al, 2014aD'Aulisa et al, , 2014bLanducci et al, 2016), the simulation set up considered only full engulfment conditions, and the possible transient evolution of fire scenario was not systematically considered. Moreover, it is worth mentioning that hydrocarbon flames (such as pool fires, jet fires, flares, etc.)…”