Experimental study on gas diffusion in subway station

Abstract

In this paper, three-dimensional ultrasonic anemometer and multi-channel anemometer have been used to monitor the flow field of a subway station in Beijing. Based on releasing sulfur hexafluoride (SF6) in the station hall, the gas transmission and diffusion range have been studied. The results show that under the natural ventilation, the gas diffusion would be controlled by a regular mainstream field. Because of obvious subsidence heavy gas tends to accumulate on the ground. The airflow on the north side of the platform is stable, which may be the main channel for gas diffusion and the gas will not be transmitted downward to the platform. As a result, during emergency response During emergency disposal, it is necessary to set an evacuation path opposite to gas diffusion. Besides, it is forbidden to turn on the top smoke exhaust system to avoid the transmission of pollutant on the ground to the breathing height.