Full-scale experimental study on fire under natural ventilation in the T-shaped and curved tunnel groups

To assess the fire risk during the construction of the pumped storage power station, full-scale fire experiments in the ventilation and safety tunnel were conducted to research temperature distribution and smoke diffusion under ventilation. The temperature profile and airflow velocity of air flow under different conditions were recorded and analyzed. The results show that the airflow velocity was mainly influenced by the large space like powerhouse and transformer chamber under natural ventilation. By analyzing smoke propagation characteristic parameters including the maximum ceiling temperature rise, smoke front arrival time and temperature variation with time, the fire-induced smoke hazard under different fire locations was assessed. The research results can provide reference data for smoke exhaust design and help developing the emergency evacuation plan for the large underground space building with similar structure.