顶部排烟对高压电缆隧道火灾烟气运动的影响

Effects of ventilation through the top vent on smoke movement in high voltage cable tunnel

基于某实际高压电缆隧道,数值研究了排烟功率和生烟率对隧道烟气运动的影响。结果表明,高压电缆隧道的通风口施加机械排烟,可能增强湍流特征,各工况结果中,720m^3/h的较低排烟功率使隧道内烟气浓度较低。外界机械排烟功率越大,越有利于降低隧道内典型位置的温度和CO2浓度并延缓其升高速度。电缆燃烧释放较多有毒烟气,人员不可贸然进入抢修。

Theoretical simulation was done based on a practical high voltage cable tunnel to investigate the effect of varied smoke exhaust rate and smoke generation rate. It is illustrated that the smoke movment mode might be disturbed by the external ventilation by increasing the turnbulence intensity. Within the simulation cases, with a small ventilation rate of 720 m^3/h,the smoke density in the tunnel can be pretty low. On the other hand, the temperature and CO2 concentration in typical locations in tunnel is lower with a higher external ventilation. And, it is suggested that people should not be allowed to go into the tunnel during the cable fire because of the heavy smoke released in fire.