受限空间内细水雾抑制熄灭火焰过程中一氧化碳的生成率

Carbon Monoxide Production Rate During Fire Suppression with Water Mist in Confined Space

细水雾抑制熄灭火焰过程中一氧化碳的浓度是评价细水雾灭火系统安全可靠性的一个重要参数.本文通过受限空间内细水雾抑制熄灭障碍火的模拟实验研究,发现细水雾抑制熄灭火焰过程中一氧化碳生成率存在两种控制模式,即燃料控制模式和细水雾流量控制模式.实验结果表明,在燃料控制模式下,一氧化碳生成率随着燃料流量的增大而增大;在细水雾控制模式下,一氧化碳生成率随着细水雾流量的增大而增大.为了获得两种控制模式的临界转变条件,对燃料控制模式和细水雾控制模式的临界工况进行水蒸气含量分析.通过理论分析,得到一氧化碳生成率控制模式转变的水蒸气含量临界范围与Suh and Atryeya理论基本一致,即空气中水蒸气质量分数达到25%～65.5%时,水蒸气对火焰的作用从化学作用转为物理作用,一氧化碳生成率控制模式开始转变.

The concentration of carbon monoxide during fire suppression with water mist is one of the important parameters for safety evaluation of water mist system. Based on the experimental results of fire suppression with water mist in confined space, it is found that the carbon monoxide production rate during fire suppression is controlled in two modes. One is fuel controlled mode, and the other is water mist flux controlled mode. In the fuel controlled mode, the carbon monoxide production rate increases with the increase of fuel flux. In the water mist flux controlled mode, the carbon monoxide production rate increases with the increase of water mist flux. In order to classify the critical condition for transformation between these two modes, the concentration of water vapor in confined space is analyzed. The results show that the critical concentration of water vapor for the mode transformation is 25%--65.5%, which is consistent with Sub and Atryeya＇s conclusion.