电缆隧道早期火情识别技术的有效性模拟技术研究

Study on effectiveness simulation technology of early fire identification technology in cable tunnel

电缆隧道是市政基础设施的有机部分,其优势在于可集中布置和管理电力与通信等领域管线设备,且对地面活动影响较小。由于被埋藏于地下,在火灾情势下的救援难度较大,经济损失与人员伤亡易失控。因此,为探究电缆隧道早期火情的识别机理,有必要对其中的早期火情识别与探测进行模拟分析和研究。以实际项目中常见的T型电缆隧道为分析对象,对不同探测系统的有效性进行模拟。根据火源位置、气流速度等参数差异,对所设计5种工况进行分析,并对隧道电缆在不同工况下的温度和燃烧率进行模拟仿真。结果表明:合理敷设和间距能够降低电缆隧道火灾的温度和燃烧率;温度与烟气浓度临界值出现于交叉点处,在两端方向出现突变;若气流速度低于0.95 m/s,探测器预警失效。

Cable tunnel is an organic part of municipal infrastructure,which has the advantage of centralized layout and management of pipeline equipment in power and communication fields,and has little impact on ground activities.Due to being buried and underground,it is difficult to rescue in case of fire,and economic losses and casualties are easily out of control.Therefore,in order to explore the identification mechanism of early fire in cable tunnels,it is necessary to conduct simulation analysis and research on early fire identification and detection.Taking the common T-shaped cable tunnel in the actual project as the analysis object,the effectiveness of different detection systems is simulated.According to the difference of fire source location,air velocity and other parameters,five working conditions have been analyzed.The simulation results have shown that reasonable laying and spacing can reduce the temperature and burning rate of cable tunnel fire,the critical values of temperature and flue gas concentration appeared at the intersection,and there were abrupt changes at both ends;The detector failed while the air velocity was lower than 0.95 m/s.