Abstract: In view of the lack of full-scale experimental studies related to the living conditions of people caused by fire in subway carriages, this paper studied the changes of environmental conditions in the fire scene inside subway carriages through full-scale experiments and numerical simulation based on the structure of Shenyang subway carriages. The harm of fire to human body was analyzed from four aspects: temperature, toxic gas, visibility and thermal radiation. The results show that the combustion power of fuel in closed subway carriages is significantly lower than that in open space due to the limited oxygen supply. The high temperature smoke spreads uniformly at the top of the carriage, and the spreading speed is positively correlated with the combustion power. The dimensionless fitting equation of temperature distribution above the fuel along the axial direction of the top of the carriages are obtained through the full-scale combustion experiment. Among the three combustibles set in this study, the order of harm to human body is 1 000 mL oil pan fire >500 mL oil pan fire > duffel bag.

Key words: closed subway carriages, fire, smoke spreading, heat radiation