Article,
Off-site ignition probability of flammable gases
Journal of Hazardous Materials, 71 (1-3): 409--422 (Jan 7, 2000)
DOI: http://dx.doi.org/10.1016/S0304-3894(99)00090-4
Abstract
A key step in the assessment of risk for installations where flammable
liquids or gases are stored is the estimation of ignition probability.
A review of current modelling and data confirmed that ignition probability
values used in risk analyses tend to be based on extrapolation of
limited incident data or, in many cases, on the judgement of those
conducting the safety assessment. Existing models tend to assume
that ignition probability is a function of release rate (or flammable
gas cloud size) alone and they do not consider location, density
or type of ignition source. An alternative mathematical framework
for calculating ignition probability is outlined in which the approach
used is to model the distribution of likely ignition sources and
to calculate ignition probability by considering whether the flammable
gas cloud will reach these sources. Data are collated on the properties
of ignition sources within three generic land-use types: industrial,
urban and rural. These data are then incorporated into a working
model for ignition probability in a form capable of being implemented
within risk analysis models. The sensitivity of the model results
to assumptions made in deriving the ignition source properties is
discussed and the model is compared with other available ignition
probability methods.
