Unorganized ventilation in subway stations with Platform Screen Doors

•This paper presents a method to simulate unorganized ventilation in a subway station and research the influencing factors.•The resistance coefficient of PSD was determined by field test with range of 0.11-0.35.•Most subway stations in China no longer require mechanical fresh air considering the unorganized fresh air.

Urban railway transit is rapidly developing in China. Subway networks regularly use Platform Screen Doors (PSD) due to their safety and affordability. However, unorganized ventilation, which introduces fresh air and increases the cooling load of the subway station, still occupies the station entrance (under the action of piston wind that leaks into the station at the PSD). This paper presents a method to simulate unorganized ventilation in a subway station and verifies the accuracy of the simulation method via a field test. The resistance coefficient of PSD, a key simulation input parameter, was determined by field test to be in the range of 0.11-0.35. Simulation results show that unorganized ventilation has a large range from 4.1 to 13.2 m3/s due to the complexity of the influencing factors. Most subway stations in China no longer require mechanical fresh air considering the unorganized fresh air.