Although tunnel piston wind brings a huge amount of fresh air to the subway station, it also carries tunnel particles into the station, which deteriorates the air quality of the station, especially the platform. In this paper, brake wear particles during train braking are considered as particle source term. PM10 mass concentration in the platform air is used as the air quality evaluation index, and the temporal and spatial variation of PM10 mass concentration is mainly studied. The results hope to provide a theoretical basis for the utilization of piston wind and improvement of platform air quality.
The main conclusions are as follows:
1. After the train stops in the station for 10s, the average PM10 mass concentration of platform reaches the maximum value of 11.1 μg/m3. When a train passes through the station, the average PM10 mass concentration in the platform increases by 1.2 μg/m3.
2. The maximum instantaneous PM10 mass concentration occurs in the middle of the platform with its value of 12.8 μg/m3. After the train leaves the station, particles are mainly distributed at the end of the platform.
3. It is quite necessary to install particle adsorption devices in the tunnel. For the station, the end of the platform is more recommended to install vacuum cleaners. These measures are very critical to the passengers health. |