Research on the fire extinguishing efficiency of low-pressure water mist in urban underground utility tunnel cable fires
In order to study the effectiveness of low-pressure wa-ter mist fire extinguishing in urban underground integrated pipe corridor cable fire and to identify the key factors influencing its ef-ficiency,a scaled-down test platform for low-pressure water mist fire extinguishing in utility tunnels was constructed,and a serial of fire extinguishing tests were conducted.The test results demon-strate that low-pressure water mist can rapidly and effectively ex-tinguish cable fires in utility tunnels,with the quickest fire extin-guishing time of 7 s.Within 50 s of activating the system,the in-ternal temperature of the tunnel can be reduced from 650℃to 40℃.The changes in pressure and nozzle flow coefficient have a significant impact on the fire extinguishing efficiency of low-pressure fine water mist.The fire extinguishing time is shortened by up to 75% and 66.7% respectively,and the average cooling rate is highest at 8.2℃/s and 7.43℃/s;The change in nozzle spacing has a relatively small impact on fire extinguishing effi-ciency,with a maximum reduction of 47.3% in fire extinguishing time and an average cooling rate of 6.1℃/s.
low-pressure water mistutility tunnelcable firefire extinguishing efficiency
NETL
NSTL
万方数据
