不同坡度条件存在隔离带燃料床地表火蔓延试验模拟研究  

Investigation of surface fire spread in the presence of fire break with variable slope angles

作　　者：郭瀚文 高云骥 陶浩文 张玉春 张颖 徐永波 GUO Hanwen;GAO Yunji;TAO Haowen;ZHANG Yuchun;ZHANG Ying;XU Yongbo(Faculty of Geosciences and Environment Engineering,Southwest Jiaotong University,Chengdu 610031,China;Mianyang Fire Brigade of Sichuan Fire Rescue Corps,Mianyang 621052,Sichuan,China;Fire Rescue Brigade of Jinchuan County,Aba Tibetan and Qiang Autonomous Prefecture 624199,Sichuan,China)

机构地区：[1]西南交通大学地球科学与环境工程学院,成都610031 [2]四川省消防救援总队绵阳市消防支队,四川绵阳621052 [3]金川县消防救援大队,四川阿坝藏族羌族自治州624199

出　　处：《安全与环境学报》2024年第6期2197-2205,共9页Journal of Safety and Environment

基　　金：国家重点研发计划项目(2022YFC3005704);国家自然科学基金项目(52108478);四川省科技计划项目(2022YFS0533)。

摘　　要：为了更好地了解斜坡条件下地表火势蔓延的特点和隔离带后的燃料引燃机制,开展了6种不同地形坡度(0°、10°、15°、20°、25°、30°)和5种不同隔离带宽度(5 cm、10 cm、20 cm、30 cm、40 cm)的地表火蔓延穿过隔离带的火行为试验研究。结果表明,在隔离带前地表火蔓延过程中,随着坡度增大,火焰由平坡时向已燃区偏倒逐渐过渡为向未燃燃料贴附,火蔓延速率、火焰长度和热流特征值均增大,火焰倾角减小。同时,在隔离带有效时,带后燃料表面温度和热流明显降低;而在隔离带失效时,带后燃料表面温度和热流与带前相比差异不大,且带后燃料温度按测点顺序依次升高。在坡度一定时,带后燃料表面温度和热流随隔离带宽度增大而减小;在隔离带宽度一定时,带后燃料表面温度和热流随坡度增大而增大。In order to investigate the effect of slope angle on surface fire spread and arrangement of fire break,a slope-adjustable forest surface fire spread experimental setup was built.Six different slope angles(0°,10°,15°,20°,25°,30°)and four different fire break widths(10 cm,20 cm,30 cm,40 cm)were considered and the fire behaviors like surface fire spread were experimentally studied.The fuels used in these experiments were dead pine needles collected in Southwest China,where forest fires occurred frequently.It is found that during the surface fire spread in front of the fire break,as the slope increases,the flame gradually tilts from burned fuel toward the unburned area,and the fire spread rate,flame length and heat flux characteristic values increase,while the flame angle decreases.Moreover,a model of surface fire radiation heat flux under the slope condition is established and the model agrees well with the experimental data of radiation heat flux.Meanwhile,according to the ignition result of the fuel after the fire break,the effect of the fire break can be divided into effective and inactive.When the fire break is effective,the fuel surface temperature and heat flux after the fire break are significantly reduced;while when the fire break is inactive,the fuel surface temperature and heat flux after the fire break are not significantly different from those before the fire break.The fuel surface temperature and heat flux after the fire break decrease with the increase of the width of the fire break.The fuel surface temperature and heat flux after the fire break increase with the increase of the slope.Therefore,this study can help to better understand the surface fire spreading characteristics under slope conditions and the mechanism of the ignition of the fuel behind the fire break.

关 键 词：安全工程 地表火蔓延 地形坡度 隔离带 火行为 

分 类 号：X954[环境科学与工程—安全科学]