The 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.

中文翻译：

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低气压下纸箱火灾燃烧特性的实验研究

这项工作的目的是研究低压下的火灾行为特征。在高空室内分别以101 kPa，75 kPa，64 kPa和59.5 kPa分别进行了两种火负荷（箱式和箱式）的纸板箱着火实验。测量放热率，质量燃烧率，残余灰分质量和辐射热通量作为主要特征参数进行分析。这些测试的结果证明了对低压气氛引起的火灾行为的重大影响。质量燃烧率表明功率函数随气压的增加而增加。残余灰分的比例随压力下降而线性增加，在19.5帕克（59.5 kPa）的火力下，残余灰分的比例高达44％。尽管与1盒式火相比，2盒式火的残留灰分比例较低，这意味着2盒式火的燃烧更加完全。101 kPa，75 kPa，64 kPa和59.5 kPa获得的有效燃烧热（EHC）分别为18.44、17.08、15.10和12.74 kJ / g。此外，基于简化的测量方法计算了散热分数，并且观察到散热分数对环境压力的依赖性较小。