Research on collaborative airflow and smoke control design for vertical shaft groups in extra-long cross-sea highway tunnels
The second underwater tunnel in Qingdao has pioneered the installation of longitudinally spaced connecting flues on the smoke exhaust ducts of both tube tunnels,linking the north-south flues to enhance ventilation efficiency.Therefore,it is essential to clarify the impact of collaborative airflow from different vertical shaft groups on the air volume and velocity in the connecting flue.Additionally,it is crucial to determine the optimal air volume ratio between the north and south lines,as well as the ideal air volume ratio between the two vertical shafts.By comparing the effects of different air volume ratios on the wind speed and utilization rate of the connecting flue,it was found that variations in the air volume ratio between the north and south lines have a relatively minor impact on the wind speed of the connecting flue.However,it can somewhat alleviate the issue of low wind speed at the center of the tunnel,which occurs due to mutual suction caused by equal air volumes on both sides.The air volume ratio between the two lines significantly affects the wind speed within the connecting flue.As the air volume ratio between the two vertical shafts shifts from 5:5 to 2:8,the average wind speed in the middle exhaust duct of the connecting flue rises from 0.89 m/s to 1.18 m/s,representing an increase of approximately 32.58％.The utilization rate of the connecting flue also increases from 41.18％to 54.75％.Therefore,it is advisable to adopt an unbalanced air volume ratio mode for the two vertical shafts.The optimal utilization rate of the connecting flue is attained with an air volume ratio of 2:8 between the two vertical shafts.The validity of the air volume ratio design was confirmed through reduced-scale model experiments.
safety engineeringconnecting fluecollaborative air volumeair volume ratioconnecting flue utilization ratesmoke control design
万方数据
维普
