Analysis of Influencing Factors on Flashover in the Long-narrow Confined Space

The traditional theory of flashover is not available for the application of flashover in a long-narrow confined space, especially about the critical condition of flashover occurrence. In this paper, according to the measurement of reduced-scale fire tests, the smoke layer's temperature, thickness, gas concentration and heat release rate of fire source were studied. Furthermore, the effects of fire source, opening and ventilation to the occurrence of flashover were further discussed. It is shown that the critical line of flashover for the different fuels is between 600 °C and 700 °C, and critical condition is different for different fuels and different openings; for the different transverse ventilation, the smoke evacuation has the best effect only when the exhaust port neat the fire is opened.