液氮及排烟共同作用扑灭电缆火灾有效性研究

城市地下综合管廊电缆火灾危险性极大。运用FDS软件模拟液氮和机械排烟共同作用、仅有机械排烟以及无液氮和机械排烟3 种工况下，综合管廊内部电缆火灾蔓延情况。分析火灾发生后综合管廊内部烟气蔓延及温度分布，发现液氮和机械排烟的共同作用能迅速扑灭火灾从而减小由于发生火灾造成严重后果的危险程度。分析不同的注氮速度和机械排烟速度对扑灭综合 管廊电缆火灾的影响，发现适当增加注氮速度和排烟速度有利于扑灭电缆火灾。

Study on the effectiveness of extinguishing cable fires under the combined action of liquid nitrogen and smoke

The cable fire risk of underground pipe gallery is extremely high. FDS software is used to simulate the flame spread of cable inside the underground pipe gallery under three conditions, namely, the combined action of liquid nitrogen and mechanical smoke exhaust, only mechanical smoke exhaust, and no liquid nitrogen or mechanical smoke exhaust. The smoke spread and temperature distribution in the underground pipe gallery after cable fire are analyzed. It is concluded that the combined action of liquid nitrogen and mechanical smoke exhaust can quickly extinguish the fire and reduce the risk of serious consequences caused by the cable fire. The effects of different nitrogen injection speeds and mechanical smoke exhaust speeds on extinguishing cable fires in the underground pipe gallery are analyzed, and it is concluded that an appropriate increase in nitrogen injection speed and smoke exhaust speed is beneficial to extinguishing cable fires.