Fire Safety Science Digital Archive

Enclosed kerosene pool fires were investigated with ventilation equivalent to normal leakage into a Room with the doors and windows closed and air in leakage due to gaps around doors and windows. A 1.9 m³ enclosed fire test facility with separate air inlet at floor level and fire product outlet at ceiling Level was used. A fully heated gas sample system was used, including unburnt he1 analysis, as total Hydrocarbons are required as well as CO to determine the combustion efficiency and the air/fuel ratio by carbon balance. This air/fuel was used to determine the adiabatic mean flame temperature of the Fire as a function of time as well as the entrained air mass flow rate. The adiabatic temperature was compared with the measured flame temperature and it was shown that the time to peak temperature was the same. The temperature difference was used to determine the global heat loss to the enclosure Walls as a function of time. The peak heat transfer per unit wall surface area was 6 kW/ m² for the highest ventilation rate. The global heat transfer to the enclosure was 70-80% of the heat release at the peak fire intensity for three ventilation air flow rates. NOx concentrations were also determined and the rate of formation of NOx was used to compute the temperature of the hot zone that formed the NOx. This temperature was shown the increase very rapidly after the start of the fire to a maximum of approximately 1500K for all three ventilation rates. The size of this hot zone was taken as a cylinder of Vertical height equal to a free pool fire flame height and diameter. The surface area of this at l5OOK was shown to account for the measured global heat transfer.