CFD modelling of the emergency ventilation of a new metro station

The design of new underground metro stations is always challenging, and those aspects related to the emergency ventilation are especially relevant due to the implications in the architecture of the station as well as in the safety of the users.

In the project of the line 7 of the Santiago de Chile metro, CFD simulations made with Pyrosim were employed to verify the adequacy of the ventilation system proposed in case of a mayor fire in the station, more specifically at the platform level. There was considered a fire with HRR of 10 MW placed blocking the main evacuation path, and the ventilation strategy was different from usual strategies at underground stations, as it was done with a Pull-Push operation, using the ventilation shafts placed at both endings of the station.

Temperature, visibility, and carbon monoxide were analysed to verify the tenability conditions along the evacuation path, which was highly demanding, as it was placed over the platform level, forming a single volume.