Experimental study of smoke characteristics in a double-deck tunnel with multiple point extraction by using branch pipe
Publication details: Borås : RISE Research Institutes of Sweden AB, 2023Description: s. 269-285Subject(s): Online resources: In: Proceedings from the Tenth International Symposium on Tunnel Safety and Security, Stavanger, Norway, April 26-28, 2023Abstract: A reduced scale 1:8 double-deck tunnel model was built to study smoke control performance of a semi-transverse ventilation system using a branch pipe to connect the lower deck tunnel to the upper smoke duct. 41 experiments were conducted to analyze the effects of different activation modes of smoke vents, heat release rates, and exhaust smoke rates on smoke spread distance. An optimum smoke control mode was found by activating two vents near the fire source when the heat release rate is 44.19 kW (8 MW at full scale) and a smoke extraction rate is 0.66 m3 /s (120 m3 /s at full scale) by using branch pipe. Results showed a linear relationship between smoke spreading distance and the volumetric flow rate of the fan, leading to the development of calculation equations. Furthermore, fire smoke spread characteristics were quantified under a typical ventilation design.A reduced scale 1:8 double-deck tunnel model was built to study smoke control performance of a semi-transverse ventilation system using a branch pipe to connect the lower deck tunnel to the upper smoke duct. 41 experiments were conducted to analyze the effects of different activation modes of smoke vents, heat release rates, and exhaust smoke rates on smoke spread distance. An optimum smoke control mode was found by activating two vents near the fire source when the heat release rate is 44.19 kW (8 MW at full scale) and a smoke extraction rate is 0.66 m3 /s (120 m3 /s at full scale) by using branch pipe. Results showed a linear relationship between smoke spreading distance and the volumetric flow rate of the fan, leading to the development of calculation equations. Furthermore, fire smoke spread characteristics were quantified under a typical ventilation design.