细水雾熄灭障碍物火的实验研究和数值模拟

为了研究细水雾灭火系统在网状和条状障碍物阻隔条件下的灭火效果,采用全尺寸试验研究和数值模拟的方法研究了障碍物的形状,位置,遮挡面积以及细水雾工作压力对灭火效果的影响.实验结果表明:提高压力有助于快速有效地熄灭障碍物火;障碍物的位置是影响灭火效果的重要因素,近距离的覆盖使细水雾难以进入火区.障碍物下出现局部高温区,余火难以扑灭,灭火时间至少需要56 s;而障碍物距离火源较远时,卷吸作用下细水雾仍能均匀的进入火区,发挥冷却作用,灭火时间在18 s以内;网状障碍物的遮挡面积,对灭火效果影响不大;相同遮挡面积条件下,条状障碍物火比较难熄灭.

Experimental and Numerical Study on Fire Extinguishment Efficiency of Water Mist with Obstruction

The full scale tests and numerical simulations were carried out to investigate the validity of the obstacle fires extinguishment by water mist on the conditions of reticulation and strip obstacles.Shape,location,and shielding area of the obstacles and water pressure were considered as the main influencing factors on the extinguishment effect.The results show that increase of the pressure is helpful to improve the validity.Location of the obstacle is the crucial influencing factor.It is difficult to get into the flame for mist because of near coverage,and a partial high temperature zone occurs under the obstacle,so the remaining fire is hard to be put out.The extinguishment time is 56 s at least.With far coverage,water mist scatters equally over the flame relatively by entrainment.The cooling effect from mist is obvious;the extinguishment times are within 18s.There is little effect with different shielding area of the reticulation obstacles on the extinguishment.With the same shielding area,fires with strip obstacles are difficult to be extinguished.