Environmental Hazards Associated with a Fuel Leakage in a Confined Space of Air

Abstract

Hazardous situations associated with a fuel leak into a confined space of air at ambient temperature and pressure have been simulated by a long tube of air with a fuel container located at one side. At the other side, the boundary conditions of having a closed end (zero diffusion flux) or an open end (zero concentration of leaking fuel) have been considered. A generalized mathe matical model of the transient one-dimensional diffusion equation has been utilized to establish the approximate size of the flammable zone as a function of dimensionless diffusion time and tube geometry. It has been suggested that such solutions are valid for situations when mixing occurs by molecular and/or convective diffusion provided adequate estimates of the effective diffusivities are made. Moreover, the model facilitates the calculation of the time after which the fuel is dissipated in the surrounding atmosphere until it is diluted below the lower flammability limit and thus, the entire confined space becomes safe. Applications of such a model for some typical fuels is also presented and discussed.

Keywords

diffusion mixing mass transfer fire hazards stratified combus tible mixtures safety.

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