Study on Fire Extinguishment Performance of Water Mist System in a Utility Tunnel

The power cable fire in an utility tunnel is difficult to control due to its characteristics of narrow and long structure, cable layer arrangement, and variable fire locations. Water mist system is one of commonly used method for fire control. This paper studied the fire extinguishing efficiency of high-pressure water mist system in utility tunnel by large eddy simulation (LES). In order to compare the fire extinguishing effect of the water mist system, two working conditions are designed, that is, the utility tunnel with water mist system and without water mist system. Results have shown that continuously operating of high-pressure water mist system can extinguish cable fires effectively. The cooling effect of the water mist is obvious and it can control fire development or extinguished fire. The temperature of utility tunnel would be reduced so as to prevent the structure from being destroyed.