分析细水雾与火灾的传热机制.在尺寸为6.0 m×1.5 m×2.0 m的隧道模型中部放置0.25 m×0.20 m×0.05 m的油盆,进行柴油池火灭火实验,分析排烟模式、工作压力、通风风速对细水雾灭火的影响.结果表明,细水雾+顶部排烟耦合系统的灭火时间最短,细水雾压力增加有利于抑制灭火初期的强化燃烧现象.6 MPa、12 L/min细水雾作用下,纵向排烟风速不宜超过0.5 m/s,其灭火机理主要为对热辐射的衰减作用;顶部排烟风速可以达到1.0 m/s,其灭火机理主要为对火焰的冷却作用.10 MPa细水雾灭火时间受1.0 m/s以下风的影响可以忽略不计.15 MPa细水雾灭火时间受1.5 m/s以下风的影响可以忽略不计.10 MPa及以上压力细水雾耦合通风系统的灭火机理为火焰冷却及热辐射衰减的综合作用.%The heat transfer mechanism between water mist and fire was introduced. Diesel pool fire by 0.25 m× 0.20 m× 0.05 m was used in the middle of tunnel model of 6.0 m×1.5 m×2.0 m to carry out the fire extinguishing experiments. The effect of ventilation model, working pressure and ventilation velocity on the fire sup-pression of water mist was analyzed. Results illustrated that, fire suppression time of top smoke discharge and water mist coupling system is the shortest, and the increase of water mist pressure is helpful to control the combustion intensification phenomenon at the initial stage of water mist application. Under the effect of 6 MPa and 12 L/min water mist, longitudinal smoke discharge velocity should be under 0.5 m/s by the attenuation effect on the radiant heat flux received by fire source, and top smoke discharge velocity can reach 1.0 m/s under the cooling effect on the flame. Fire sup-pression time of 10 MPa water mist will not be impacted by smoke discharge velocity under 1.0 m/s, and fire suppression time of 15 MPa water mist will not be impacted by ventilation velocity under 1.5 m/s. The fire suppression mechanisms of water mist and venti-lation coupling system which pressure is 10 MPa and above illus-trate the comprehensive effect of flame cooling and radiant heat flux attenuation.
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