利用ISO9705全尺寸多功能热释放速率测试仪在开放空间研究了细水雾作用下K类火灾的发展过程,实验中对细水雾作用下食用油火的温度、热释放速率及烟气的主要特性参数变化规律进行了测量与研究,分析了预燃时间对灭火有效性的影响,系统地阐述了细水雾作用下K类火灾关键特性参数的变化规律.实验发现,细水雾可以有效地抑制K类火灾的发展,在其作用下火焰温度及热释放速率快速降低,并可以有效地冲刷烟气,降低一氧化碳及二氧化碳的浓度,提高氧气的浓度及火场能见度.同时利用稳定火源热释放速率模型计算了K类火灾发展阶段的热释放速率,与实验测量结果比较发现,模型可准确地预测K类火灾发展阶段的热释放速率的变化规律.
A full-scale heat release rate platform for multifunctional measurement is used to study the interaction of water mist with cooking oil fires in an open space. The heat release rate of cooking oil fires, the temperature history of flame, and the characteristic of smoke are measured and investigated in the experiment. The effect of preignition time on fire extinguishment efficiency of water mist is analyzed, and the principles of effect of water mist on cooking oil fires development are also studied. The experimental results show that cooking oil fires is restrained and extinguished by water mist effectively, the temperature and heat release rate decrease quickly with application of water mist, the concentration of carbon monoxide and carbon dioxide is decreased by water mist, and the concentration of oxygen and the visibility of smoke is increased. At the same time the heat release rate of cooking oil fires is also calculated by heat release rate model of steady fire, which shows that this model can forecast the heat release rate of the developing K-class fires.