Zhang Yongwang, Wang Lu
School of Civil Engineering, Southeast University, Nanjing 210096, China.
College of Civil Engineering, Nanjing Tech University, Nanjing 211816, China.
Materials (Basel). 2021 Sep 23;14(19):5515. doi: 10.3390/ma14195515.
Due to the flammability of materials and the vastness of space, flashover fires of large-space timber structures pose a huge threat to lives as well as the structures themselves. Therefore, it is necessary to study the critical conditions, control factors and prediction methods of flashover fires. To address this issue, hundreds of design conditions were simulated by Fire Dynamics Simulator (FDS) with variations in space size, the heat release rate (HRR) of fire source and fire growth type. A temperature-time model of the maximum temperature of the smoke layer near the ceiling () was established, and the critical condition that uses this model to predict the occurrence of flashover was determined. Furthermore, a mathematical formula was established that can accurately predict the flashover induction time when the exceeds 400 °C. This research can provide a reference for the performance-based fire safety design of large-space timber structures.
由于材料的易燃性和空间的广阔性,大空间木结构的轰燃火灾对生命以及结构本身都构成了巨大威胁。因此,有必要研究轰燃火灾的临界条件、控制因素和预测方法。为解决这一问题,利用火灾动力学模拟器(FDS)对数百种设计条件进行了模拟,改变了空间尺寸、火源热释放率(HRR)和火灾增长类型。建立了天花板附近烟雾层最高温度()的温度-时间模型,并确定了使用该模型预测轰燃发生的临界条件。此外,还建立了一个数学公式,当超过400℃时,可以准确预测轰燃诱导时间。本研究可为大空间木结构的性能化防火设计提供参考。