FireDOC Search

Author
Persson, H. | Persson, B.
Title
Paverkan fran varmestralning vid brand i cisternlager. [Impact From Heat Radiation During Tank Fires.]
Coporate
Swedish National Testing and Research Inst., Boras, Sweden
Report
SP Report 1996:06, 1996, 50 p.
Keywords
tank fires | thermal radiation | gasoline | fire tests | wall temperature | computation
Identifiers
heat radiation; calculations
Abstract
[ONLY ABSTRACT IN ENGLISH] Various models for calculation of heat radiation from tank fires have been studied. The purpose was to determine the applicability of the models and the accuracy of the results. Calculations have been made with the PHAST-program on three different tank sizes, 0 10 m, 20 m and 40 m containing gasoline. The radiation impact towards the wall and roof of neighbour tanks was calculated as a function of distance from the burning tank. Some calculations has also been compared with full-scale pool fire tests and the correlation seems acceptable, especially for the most common fueld. In general, it seems to be relevant to assume an uncertainty of up to approx. 50% between calculated and real radiation levels. The uncertainty is most connected to the fire related parameters of the fuel in full scale conditions (flame radiation, burning velocity, etc.) and the effect of wind. Calculations of the wall temperature of exposed neighbor tanks has also been made to get an idea of the time aspects concerning the likelihood for fire spread. Only the upper part of a cone roof tank (assuming a gas phase on the inside) have been considered as this seems to be the most critical condition. The calculations show that a steady state wall temperature is generally acheived within 30 minutes and the temperature varies between 100-500ºC depending on size of the burning tank and distance. If the tank is exposed to flames directly, e.g., from a bund fire, the wall temperature will exceed 500ºC within some few minutes. A critical condition was defined as when the wall temperature was exceeding the auto ignition temperature of the stored fuel. If the fuel concentration then also is within the flammable limits, ignition could occur. Some calculation was compared with full scale tests on tanks containing ethanol and the calculated time to ignition correlated reasonably well with the measurements.