【摘要】 为了研究采用横向联络排烟道结合侧壁排烟口新型排烟方式对沉管隧道火灾烟气流动的控制效果，以深圳-中山隧道为例，采用理论分析与计算流体力学相结合的方法，通过分析临界风速、烟气逆流长度和烟气分岔低温区域来研究烟气的流动特性。提出了沉管隧道火灾临界风速和烟气逆流长度的修正模型，同时还建立了烟气分岔流动低温区域长度的预测模型。结果表明，当无量纲热释放率小于0.139时，临界风速与无量纲火源热释放速率的1/3次方成正比。当纵向风速从1.5 m/s增加到4.0 m/s时，10、20、30、50 MW火灾时的峰值温度分别降低了35%、48%、46%和43%。在强纵向风速的作用下会发生烟气分岔现象，对隧道中心线和侧壁温度进行分析，得到了分岔流动低温区域长度预测模型，预测结果误差在10%以内。更多还原

【Abstract】 In order to study the smoke flow and control effect of the new smoke exhaust method of the supplementary exhaust ducts combined with the side wall exhaust vent on immersed tunnel fire, taking Shenzhen-Zhongshan tunnel as an example, the method of combining theoretical analysis with computational fluid dynamics was used to study the flow characteristics of smoke by analyzing the critical velocity, the smoke back-layering length and the low-temperature region of smoke bifurcation. A modified model of critical velocity and smoke back-layering length of immersed tunnel fire was proposed, and a prediction model of lowtemperature zone length of smoke bifurcation flow was proposed.The results show that when the dimensionless heat release rate is less than 0.139, the critical velocity is proportional to 1/3 of the dimensionless heat release rate of the fire source. When the longitudinal velocity increases from 1.5 m/s to 4.0 m/s, the peak temperatures of 10, 20, 30, 50 MW fires are reduced by 35%,48%, 46%, 43%, respectively. Bifurcation occurs under the action of strong longitudinal velocity. The prediction model of the length of the low-temperature region of the bifurcated flow is obtained by analyzing the temperature of the tunnel center line and the side wall, and the error of the prediction result is within 10%.更多还原