双层盾构隧道支管排烟量数值模拟

Numerical simulation on the smoke extraction of branch point strategy in double shield tunnel

为评估不同排烟风量下双层盾构隧道支管重点排烟的烟气控制性能及隧道内的安全疏散救援环境,依托上海某在建双层盾构隧道,借助FDS对火灾工况下支管重点排烟性能进行数值模拟。考虑2~3辆小轿车失火的不利工况,设定火灾热释放率为8 MW。分析30、40、50、60 m^3/s排烟量下隧道内烟气的扩散范围、温度场及能见度的变化规律。结果表明,40 m3/s为排烟量的临界指标。

To evaluate the performance of branch point smoke extraction strategy and evacuation environment in double shield tunnel and the fire fighting and rescue environment in tunnel under different exhaust speeds,a series of numerical simulation were conducted by FDS based on a double shield tunnel under construction in Shanghai.The scenario is2~3cars on fire and the fire power is8MW.The change rules of smoke diffusion range,temperature,and soot visibility were analyzed under different exhaust speeds of30,40,50,60m3/s.The study indicated that the exhaust speed of40m3/s is a critical index.