狭长通道内火灾烟气流动特性实验研究

Experimental research on transportation of fire-induced smoke in narrow corridor

开展汽油火实验研究火灾烟气在狭长通道中的输运特性,监测通道内的烟气运动过程和温度分布,O2、CO2和CO的体积分数变化以及烟气对通道内照度的影响。实验台全长8.5m、宽1.2 m、高1.7 m。圆形油盘直径为25cm和35cm,采用汽油作为燃料,每次用量1L。采用电子秤测量燃料质量损失速率,计算热释放速率。温度竖向分布反映烟气的分层现象,由顶棚向下逐渐降低,高温区在距顶棚30cm范围内。烟气蔓延之处O2浓度下降,CO2相应增加,当O2和CO2浓度达到极值后保持稳定。CO浓度在燃烧衰减之前一直处于升高状态,随着火焰的衰减熄灭又快速降低。照度随烟气蔓延迅速下降,通道内环境无法满足安全疏散要求。

Experiments were conducted to investigate characleristic of smoke movement with gasoline fire in narrow corridor. The smoke spread process, distribution of temperature, concentration of O2 , CO2 and CO, the change of illuminance were analyzed. The size of experiment station was 8. 5 m × 1.2 m × 1. 7 m, the diameter of oil pan was 25 cm and 35 cm, and the fuel was 1 L gasoline. The heat release rate was calculated by mass loss rate measured by electronic scale. The vertical distri bution of temperature showed the smoke stratification phenome non. High temperature region was within 30 cm below the ceil ing,and the temperature gradually reduced from ceiling to floor. The concentration of O2 dropped with the smoke filling, mean while the concentration of CO2 increased, and both of them be came stable after the extremum. The CO concentration was in a rising state before burning attenuation, then it reduced rapidly with the attenuation of fire. The illumination phmged dramatic ally with the smoke filling, and the corridor could not fit the re quirement of safety evacuation.