Optimal ventilation mode for double fires in a typical interchange subway station

This paper investigates the optimal ventilation mode for double fires in a typical interchange subway station. Numerical simulations were carried out in a full-scale subway station with different heat release rates, ventilation modes, and fire source locations. Results demonstrate that when double fires occur, activating ventilation systems in one line may affect the smoke spread in other lines due to the existence of transfer channels. For the platform-tunnel mixed exhaust mode, when the fire size is small, the optimal TVF exhaust volume range exists. There is no optimal smoke exhaust volume for double fires with the large fire size or near the ends of the platform. Under such circumstances, the subway staff should take some measures to hinder the unwanted smoke flow path.