Smoke Flow and Evacuation Safety in the Event of Fire in an Underground Rail Transit Transfer Station

• Published in: Buildings
• Main Authors: Jinbo Wang, Changqun Zuo, Qinghui Duan, Zhen Ma, Shenglong Gong
• Format: Article
• Language: English
• Published: MDPI AG 2025-08-01
• Subjects: underground rail transit transfer station; fire; smoke flow; personnel evacuation; analog simulation
• Online Access: https://www.mdpi.com/2075-5309/15/17/3008

Underground rail transit transfer stations are large-scale, complex structures with high-passenger flows, making them more vulnerable to fires and rescue challenges than other stations. Taking Zhongnan Road Metro Transfer Station in Wuhan as a project example, this study simulates two typical fire scenarios—flammable package ignition and equipment short circuits—using PyroSim to analyze changes in smoke movement, temperature, visibility, and CO concentration within the station. The required safety egress time (<i>T</i>_RSET) was determined according to the critical threshold. Then, the critical evacuation phase time (<i>t</i>_move’) at each key evacuation node was calculated by working backward from <i>T</i>_RSET. The threshold control of the open/close time nodes of the evacuation passages in the Pathfinder calculation was realized based on this time parameter. Based on the improved optimization algorithm method, personnel evacuation simulations are conducted to analyze evacuation characteristics, efficiency, and safety levels. Results show that the combustion characteristics of the fire source significantly affect the efficiency of passenger evacuation. The evacuation fails in Scenario 1 (flammable package) but succeeds in Scenario 2 (short circuit of an elevator circuit). Safety ratings for exits A–F are Level 1 (Good), Staircase 1 is Level 2 (Qualified), Staircases 2 and 3 are Level 3 (At Risk), and Staircase 4 is Level 4 (Poor). Finally, suggestions for improvement were proposed regarding size, quantity, and layout optimization of egress staircases.