Combustion behaviour of multicomponent pool fires

Abstract

This work examined combustion behaviour in multicomponent pool fires through experimentation and application of empirical, global energy balance, and computational fluid dynamics (CFD) modelling approaches. Transient pool fire experiments were conducted to measure the rate of distillation in ethanol-water mixtures. The pool composition over time was predicted adequately by a batch distillation model. Steady-state pool fire experiments were conducted to evaluate the effects of mixture ratios on maximum burning rate, flame height, and flame temperature in ethanol-water, ethanol-isopropanol, and ethanol-hexane mixtures. Combustion behaviour in these fires was strongly dependent on the vapour phase composition of the fuel. Standard correlations for estimating flame heights and temperatures showed good agreement with the experiments. The open-source CFD package Fire Dynamics Simulator (FDS) was modified to enable pyrolysis modelling for multicomponent fuels. With the new modifications, FDS was able to reproduce combustion behaviours observed in transient ethanol-heptane pool fire experiments conducted by other researchers.