Thermal radiation modelling of pool fire with consideration on the nonuniform temperature in flame volume

The accidental leakages of combustible fuel during storage and transportation cause the pool fires which impose hazardous heat on the nearby occupants and facilities mainly by thermal radiation. This paper presents a new semi-empirical radiation model, namely, the multi-layer cylindrical flame model to predict the radiant heat flux field of pool fires. As the centerline temperature of pool fire varies significantly with vertical height, a formula is proposed to characterize the vertical profile of flame surface emissive power with which the new model can predict the radiant heat flux. The reasonable layer number (the number of small cylinders used for model prediction) can be determined using sensitivity analysis. Comparisons with the experimental data of methanol, heptane, toluene and propane pool fires of different pool diameters indicate that the new radiation model can give a good prediction on the thermal radiation in both horizontal and vertical directions, in spite of fuel type and pool diameter. In comparison with the point source model and three typically single cylindrical flame models, the new radiation model seems to give encouraging results relative to the validity of model system. Sensitivity analysis is also conducted to rank the importance of model parameters.