变坡度条件下正丁醇定常流淌火非稳态燃烧行为研究

Study on unsteady combustion behavior of stationary spilling fire of n-butanol under condition of variable slope

为探究流淌火在变坡度地面的蔓延特性,丰富火灾研究理论,推进流淌火预防和风险评估的发展,采用1套自制矩形小尺度油槽系统,研究正丁醇变坡度、变泄漏速率情况下溢油定常流淌火的蔓延特性。结果表明:当泄漏速率相同时,坡度越大,正丁醇的加速过程越明显,当坡度从1°上升到4°,正丁醇扩散速率增大了40.8%;不同坡度下,正丁醇的平均火焰高度随泄漏速率的变化均呈现“上升-下降-稳定”趋势;流淌火蔓延过程中脉动方式分为2种:“跳跃-爬行”和“跳跃-爬行-回缩”;当泄漏速率较小时,流淌火蔓延过程中的脉动频率随油槽坡度的增大而增大,当泄漏速率较大时,脉动频率不再随油槽坡度的改变而发生明显趋势变化。

In order to explore the spread characteristics of spilling fire on the ground with variable slope,enrich the fire research theories,and promote the development of spilling fire prevention and risk assessment,a self-made rectangular small-scale oil groove system was used to study the spread characteristics of stationary oil spilling fire for n-butanol under variable slope and variable fuel leakage rate.The results showed that when the leakage rate was the same,the greater the slope,the more obvious the acceleration process of n-butanol,and when the slope increased from 1°to 4°,the diffusion rate of n-butanol increased by 40.8%.Under different slopes,the average flame height of n-butanol presented a trend of“rising-falling-stable”with the change of leakage rate.There were two types of pulsation in the spread process of spilling fire,including“jump-crawl”and“jump-crawl-retract”.When the leakage rate was small,the pulsation frequency during the spread process of spilling fire increased with the increase of oil groove slope.When the leakage rate was large,the pulsation frequency will no longer change obviously with the change of oil groove slope.