通风量对火灾烟气中CO_2和CO释放的影响

Influence of ventilation on the release of CO_2 and CO in fire smoke

该文利用文献中评价材料毒性的原始实验数据,从烟气毒性物质释放的角度,分析了火灾烟气中CO2和CO的释放特性,并着重分析了通风量的影响机理。研究发现:CO2和CO的释放受燃烧模式的影响。在通风控制模式下,木材的扩散燃烧按照挥发分和固定碳燃烧分阶段进行,并受扩散供氧和燃烧耗氧之间制约关系的影响,其烟气成分的释放也具有上述特点。另外,数据分析表明,燃烧存在临界通风量和着火延迟。通风量具有强化燃烧和稀释、掺冷烟气的双重作用。

The release characteristics of CO_2 and CO in fire smoke as well as the influence of airflow were investigated by analyzing experimental data appraising material toxicity in the literature. The research results show that the oxygen supply method has such a powerful influence on the CO_2 and CO release mechanisms that the structural characteristics of the experimental apparatus should be considered. The diffusion-controlled combustion is a two stage combustion process for the volatiles first and then the fixed carbon, with the combustion process influenced by the restricted O_2 supply and consumption. The release of the smoke components is also related to the airflow. The data shows a critical airflow rate and a kindling delay time. The ventilation accelerates the combustion but also dilutes and cools the smoke.