地铁单面坡隧道列车火灾通风模式研究

针对地铁单面坡隧道连续下坡距离长、提升高度大的特点，以国内某城市地铁线路为研究对象，构建列车火灾通风排烟数值计算模型，并采用1:20模型实验对数值计算精确度进行验证，通过考虑列车起火位置、风机开启模式和隧道断面形式等因素，对火灾烟气扩散过程、疏散平台上方烟气温度和气体浓度进行分析。研究结果表明:列车起火后，单洞单线隧道2端车站应各开启2台隧道风机，单洞双线隧道除开启射流风机外，2端车站应各开启4台隧道风机执行相应的排烟和送风模式进行烟气控制；由于单洞双线隧道中热损失和空气卷吸量较大，火灾烟气温度、CO和CO2浓度均低于单洞单线隧道；采用纵向通风控制烟气逆流的同时，下风向区域的烟气沉降作用较为明显，防排烟设计中应充分考虑列车中部火灾下风向车厢区域的危险性，合理确定应急响应模式。

Study on ventilation mode for train fire in metro tunnel with single side slope

Aiming at the characteristics of long continuous downhill distance and large lifting height in the metro tunnel with single side slope, taking the metro line of a city in China as the research object, a numerical calculation model on ventilation and smoke exhaust of train fire was constructed, and the accuracy of numerical calculation was verified by using the 1:20 model experiments. Considering the factors such as the location of train fire, activation mode of fans, section form of tunnel and other factors, the diffusion process of fire smoke and the smoke temperature and gas concentration above the evacuation platform were analyzed. The results showed that after the occurrence of train fire, the stations at both ends of single hole and single track tunnel should activate two tunnel fans respectively, and the stations at both ends of single hole and double track tunnel should activate four tunnel fans respectively and execute the corresponding smoke exhaust and air supply mode to control the smoke in addition to activating the jet fans. Due to the larger heat loss and air entrainment in the single hole and double track tunnel, the smoke temperature, CO concentration and CO2 concentration were lower than those in the single hole and single track tunnel. When the longitudinal ventilation was activated to control the smoke backflow, the smoke descendent effect in the downwind area was more obvious. The risk of downwind carriage area in case of fire at middle of train should be fully considered in the design of smoke control and exhaust, and the emergency response mode should be determined reasonably.