环境风下大型储罐火灾火焰特征与热物理性质研究

Study on flame characteristics and thermophysical properties of large storage tank fire under ambient wind

为研究燃油储罐火灾过程中的火焰特性与火灾发展过程,基于相似准则设计小尺度实验,通过数值模拟进行全尺度实验验证,指出风速状态对储罐火灾的火焰特征、特性的影响。研究结果表明:处于软风、轻风状态时,甲醇汽油的燃烧会更快进入稳定燃烧阶段,维持稳定阶段的时间更久。火焰高度与火焰倾角的变化随着风速的增加逐渐减小并逐渐趋于平缓、火焰最高温度逐渐减小,但对火焰轴线的温度分布影响不明显;在无风状态时,风速的增加对达到热释放速率最大值的时间影响不大,但对热释放速率最大值影响较为显著;在软风、轻风状态时,风速对达到热释放速率最大值的时间影响较大。通过全尺度数值模拟实验验证得到相似实验与数值模拟实验之间的相对误差基本分布在15%以下,具有一定可靠性。研究结果可为燃油储罐火灾的安全性及其小尺度相似实验提供设计参考。

In order to study the flame characteristics and fire development process in the fire process of fuel storage tank,a small-scale experiment was designed based on the similarity criterion,and the full-scale experimental verification was conducted by numerical simulation.The influence of wind speed on the flame features and flame characteristics of storage tank fire was pointed out.The results show that the combustion of methanol gasoline will enter the stable combustion stage faster and maintain the stable stage for a longer time under the soft and light wind conditions.With the increase of wind speed,the flame height and flame angle decrease gradually and tend to be flat,and the maximum flame temperature decreases gradually,but the influence on the temperature distribution of flame axis is not obvious.When there is no wind,the increase of wind speed has little effect on the time to reach the maximum heat release rate,but has significant effect on the maximum heat release rate.Under the soft wind and light wind,the influence of wind speed on the time to reach the maximum heat release rate is great.Through the full-scale numerical simulation experimental verification,it is found that the error value is mainly distributed below 15%,which has a certain reliability.The research results can provide design reference for the safety of fuel storage tank fire and its small-scale similar experiments.