Heat Flux Contours from Liquefied Petroleum Gas Pool Fire Using Computational Fluid Dynamics Simulation

Abstract

Thispaperpresents a studyof liquefiedpetroleum gas (LPG)pool firebehaviors anddistance
estimation of 8 kW/m2 radiant heat flux level radiating from various sizes of the pool fires using
Fire Dynamics Simulator (FDS). Ten square pool fires with widths in a range of 2 – 20 meters
were modeled in a computational domain size of 65 x 100 x 60 cubic meters using a grid size
of approximate 0.6 meter. Weather and wind speed data in the Eastern part of Thailand were
input to the models. Radiant heat fluxes at pool fire base level were measured by solid boundary
method and radiant heat fluxes in the air at levels of 1 meter, 8 meters and 13 meters above
the pool fire base were measured by gas-phase devices. Heat release rates of the LPG pool fires
as calculated by FDS were approximately the same as theoretical results with the relative error
in the range of 2.8 – 2.9 percent. The trend of pool fire flame lengths was in accordance with
Thomas’s correlation [1]; the average relative error was at 8.7 percent. Flame tilt angles were
less than the angles determined using AGA’s correlation [2] with the average relative error as
high as 32.7 percent. At the pool fire base level, the radiant heat flux of 8 kW/m2 can radiate
to distance in the range of 10.2 – 44.6 meters away from the pool fire center. At 1 meter and
8 meters above pool fire base, the radiant heat flux of 8 kW/m2 can radiate to distance in the
range of 7.5 – 52.5 meters from the center of a pool fire with width of 2 - 14 meters and to
distance beyond 52.5 meters from the center of a pool fire with width of 16 meters or greater.
At 13 meters above pool fire base, the radiant heat flux of 8 kW/m2 can radiate to distance in
the range of 7.5 – 47.5 meters from the center of a pool fire with width of 2 – 12 meters and to
distance beyond 52.5 meters from the center of a pool fire with width of 14 meters or greater