中蒙边境草原无风条件下可燃物燃烧火行为模拟

Simulation study on fire behavior on the China-Mongolia border in windless conditions

【目的】中蒙边境地区二连浩特市、东乌旗和新巴尔虎右旗草原易发生火灾,对当地生态环境和周边城市安全造成极大威胁。研究中蒙边境草原无风条件下可燃物燃烧火行为参数,可为中蒙边境草原可燃物管理和草原火灾预防提供理论依据。【方法】通过外业调查、样品采集,运用燃烧床以及热电偶等室内模拟并测定无风条件下可燃物的火行为,对可燃物火行为指标进行模拟分析。【结果】无风条件下,二连浩特市、东乌旗和新巴尔虎右旗室内模拟燃烧的火强度分别为780.44、805.80和1195.60 kW/m,蔓延速度分别为0.61、0.45和0.67 m/min,火焰平均高度分别为30.30、35.53、33.90 cm,火焰平均温度分别为481.97、529.33、389.93℃,热辐射分别为0.45、1.20、1.44 kW/m^(2)。【结论】二连浩特市、东乌旗、新巴尔虎右旗草原可燃物阻滞时间分别为28、15、22 s;二连浩特市在发生火灾时温度波动维持的时间较长,火灾隐患大;东乌旗草原可燃物阴燃热辐射接近火焰热辐射,持火力强,具有较大的复燃可能性。

【Objective】The China-Mongolia border is prone to grassland fires in Erenhot,the East Ujimqin Banner and the New Barag Right Banner,threatening livelihoods and the local environment.Studying the parameters of fire behavior for grassland fuel on the China-Mongolia border in windless conditions can provide a theoretical basis for the grassland fuel management and grassland fire prevention.【Method】Based on field investigations and sample collection,a combustion bed and thermocouple were used to simulate and measure the behavior of combustibles,and the fire behavior indexes were simulated and analyzed.【Result】Simulations for windless conditions in Erenhot,the East Ujimqin Banner and the New Barag Right Banner,respectively,showed a fire intensity of 780.44,805.80 and 1195.60 kW/m;a spread rate of 0.61,0.45,0.67 m/min;an average flame height of 30.30,35.53,33.90 cm;average flame temperature of 481.97,529.33 and 389.93℃;heat radiation,0.45,1.20 and 1.44 kW/m^(2),and blocking time of combustibles,28,15 and 22 s.【Conclusion】Long periods of temperature fluctuation are observed for grassland fires in Erenhot,and the risk of fire is high.In the East Ujimqin Banner,the smoldering heat radiation of combustibles is close to flame heat radiation and the holding power of fires is strong,making grassland fires likely.