Computational Models for Gas Cloud Temperature Analysis in Fires

Fire safety engineering involves the mechanisms of conduction, convection, and radiation. In engineering structures of industrial applications associated with hydrocarbons, fire is defined as a combustible vapor or gas that combines with an oxidizer in a combustion process that manifests in the evolution of light, heat, and flame. Within the risk assessment and management framework (as described in Chap. 16), the impacts of elevated temperatures generated by fire are the primary concerns regarding the structural loads that result from hazards. Fire events usually occur due to the release of hydrocarbons from flanges, valves, seals, vessels, or nozzles with ignition from various kinds of sparks. Pool fires are associated with released oils and jet fires occur as a result of leaking gases. This chapter presents the modeling practices of gas cloud temperature analysis in fires. Fire curves must be defined to predict gas cloud temperatures over time. Empirical formulations of fire curves are available for industry practices. In this chapter, the modeling techniques for refined computational fluid dynamics (CFD) simulations are presented to compute the gas cloud temperature versus time history. As gas cloud temperatures are transferred into structures, heat transfer analysis must be undertaken to determine the temperatures in structures for the crashworthiness analysis (as described in Chap. 12).