Measurement of Flame Emissivity of Hydrocarbon Pool Fires

摘要

Flame emissivity is an important parameter in the study of pool fires. A series of pool fire experiments are carried out with four different fuels namely diesel, gasoline, hexane and kerosene for pool diameters of 0.10 m, 0.13 m and 0.20 m. Flame emissivity at a height of 0.25 times the pool diameter from the base is mea sured by observing the flame with reference to a black body using infrared camera. Influence of pool diameter (0.3 m, 0.34 m, 0.5 m, 0.7 m and 1.0 m) on flame emissiv ity at a height of 0.25 times the pool diameter is studied with diesel as the fuel. Vari ation of flame emissivity with the height of the flame along the center of diesel pool fire is investigated for diameters of 0.3 m, 0.5 m, 0.7 m and 1.0 m. It is observed that the flame emissivity is less at the tip of the flame in comparison with that at the base of the pool fire. The measurement of flame emissivity by observing flame with refer ence to a black body using infrared camera is corroborated with the measurements conducted with reference to an electrically heated black body for diesel pool fires with diameters 0.3 m, 0.5 m and 0.7 m. Flame emissivity is also inferred from the mass burning rate measurements for diesel oil pool fires of 0.3 m, 0.5 m, 0.7 m and 1.0 m diameters. Flame emissivities are independent of the measurement method. Temperature and surface emissive power distributions of the diesel pool fires for diameters 0.3 m, 0.5 m, 0.7 m and 1.0 m are computed using infrared thermography.