Experimental study on the burning behavior of cardboard box fire under low air pressure

Abstract

SummaryThe objective of this work is to study the fire behavior characteristics under low pressures. Cardboard box fire experiments of two kinds of fire load, 1‐box and 2‐box fires, were conducted separately at 101 kPa, 75 kPa, 64 kPa, and 59.5 kPa in an altitude chamber. The heat release rate, mass burning rate, residual ash mass and radiative heat flux were measured as the principal characteristic parameters for analysis. The results of these tests demonstrated the significant effects on fire behaviors caused by low‐pressure atmosphere. The mass burning rate shows power function growth with the air pressure as . The proportion of residual ash increases linearly with the pressure drop, and it reaches as high as 44% for 1‐box fire at 59.5 kPa. While the proportion of residual ash for 2‐box fire is lower compared with 1‐box fire, which means the combustion of 2‐box fire is more complete. The effective heat of combustion (EHC) obtained for 101 kPa, 75 kPa, 64 kPa, and 59.5 kPa are respectively 18.44, 17.08, 15.10, and 12.74 kJ/g. Furthermore, the heat radiation fraction was calculated based on the simplified measuring method and it is observed that radiation fraction depends less on the environment pressure.