用锥形量热仪研究细水雾抑制熄灭PVC火

利用锥形量热仪和单流体细水雾系统研究了细水雾抑制PVC火的过程，并观察了重燃现象的发生，测量了实验中热释放速率及O2，CO2，CO和烟气的浓度变化，并对不同细水雾工作压力及不同热辐射流量下的结果进行了比较。由实验可知细水雾能快速扑灭PVC火，且压力越大灭火越迅速，但是在灭火后停止施加细水雾会发生重燃现象，且重燃发生的时间长短与作用在燃料表面的水量有关。

Study of Suppressing PVC Fire with Water Mist Using a Cone Calorimeter

In this paper, the action of water mist on PVC fires in a cone calorimeter under different external radiant heat fluxes was studied and the reignition of the PVC fires was analyzed. Water mist was generated by a single pressure nozzle. Physical characteristics of the water mist were measured by LDV/APV system. The heat release rate, oxygen, carbon dioxide, and carbon monoxide concentrations and other important parameters of the interaction under various conditions were measured by cone calorimeter. The experiment illustrated that water mist would suppress the PVC fire by evaporation cooling, oxygen displacement and radiant heat attenuation. After the fire was extinguished and water mist was shut off, fire might reignite after a period of time. The reignition time depended on the total quantity of water mist.