Numerical Simulation of Suction-type Smoke Exhaust Strategy for Super-long Highway Tunnels with Parallel Pilot Tunnel
(1. Yellow River Engineering Consulting Co., Ltd., Zhengzhou 450003; 2. Institute of Disaster Prevention Science and Safety Technology,Central South University, Changsha 410075)
Abstract：
In order to explore a new suction-type smoke exhaust mode using the parallel pilot tunnel as the smoke exhaust duct, a numerical model of a super-long tunnel with the parallel pilot tunnel is established to study smoke spread characteristics and temperature distribution law in the tunnel during smoke exhaust through the parallel pilot tunnel. The results indicate that the suction-type smoke exhaust using the parallel pilot tunnel can effectively suppress the spread of smoke in the main tunnel. At 100 seconds after the fire, there is basically no smoke in the main tunnel,and at 900 seconds, the smoke reaches a stable state, and it no longer spread to both sides of the main tunnel. As the smoke exhaust volume at both ends of the parallel pilot tunnel increases, the spread distance of smoke in the main tunnel gradually decreases when it becomes stable. When the total smoke exhaust volume at both ends of the parallel pilot tunnel is 600 m3/s, the smoke is completely controlled within the range of the three open smoke discharge ducts.When three cross passages are opened for smoke exhaust, the highest smoke temperature rise of the ceiling drops with the increase of smoke exhaust volume. When two cross passages are symmetrically opened for smoke exhaust,the maximum smoke temperature rise of the tunnel ceiling does not change significantly with the increase of smoke exhaust volume. In suction-type smoke exhaust using parallel pilot tunnel, the smoke temperature below the tunnel ceiling exhibits exponential decay, and the decay rate of smoke temperature is almost independent of the opening mode of the cross passage and the exhaust volume.
WANG Fangchao1 LIU Hongsen1 CHEN Changkun2 JIAO Weibing2
.Numerical Simulation of Suction-type Smoke Exhaust Strategy for Super-long Highway Tunnels with Parallel Pilot Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(5): 120-127
2023, Vol. 60 