TY - JOUR
T1 - Experimental analysis of the effect of the ramp slopes on the maximum exceedance temperature in a branched tunnel fire
AU - Li, Jiaxin
AU - Li, Yanfeng
AU - Li, Junmei
AU - Zhong, Hua
AU - Zhao, Jianlong
AU - Xu, Desheng
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2023/1
Y1 - 2023/1
N2 - This research aims to establish a series of small-scale experiments to analyze the effect of ramp slopes on the temperature distribution of Liquefied Petroleum Gas (LPG) fire in a model branched tunnel under longitudinal ventilation. The heat release rate under experimental conditions reached 2.57 kW to 7.70 kW and five ramp slopes of 0 %, 3 %, 5 %, 7 % and 9 % were conducted. For a specific given bifurcation angle, the maximum exceedance temperature of the fire in the expanding region before the bifurcation angle is measured and analysed. Results show that the maximum exceedance temperature in the main tunnel increases as the ramp slope decreases, which is mainly because the stack effect enhances the entrainment of the air and accelerates the smoke flow. Furthermore, the modified model of the maximum exceedance temperature, which could consider the influence of ramp slope for a branch tunnel fire is established according to the experimental results. The predicted results agree well with those of the experimental study for the main tunnel. The results could provide a reference and contribute to the knowledge of smoke extraction strategies designed for branched tunnels.
AB - This research aims to establish a series of small-scale experiments to analyze the effect of ramp slopes on the temperature distribution of Liquefied Petroleum Gas (LPG) fire in a model branched tunnel under longitudinal ventilation. The heat release rate under experimental conditions reached 2.57 kW to 7.70 kW and five ramp slopes of 0 %, 3 %, 5 %, 7 % and 9 % were conducted. For a specific given bifurcation angle, the maximum exceedance temperature of the fire in the expanding region before the bifurcation angle is measured and analysed. Results show that the maximum exceedance temperature in the main tunnel increases as the ramp slope decreases, which is mainly because the stack effect enhances the entrainment of the air and accelerates the smoke flow. Furthermore, the modified model of the maximum exceedance temperature, which could consider the influence of ramp slope for a branch tunnel fire is established according to the experimental results. The predicted results agree well with those of the experimental study for the main tunnel. The results could provide a reference and contribute to the knowledge of smoke extraction strategies designed for branched tunnels.
KW - Branched tunnels
KW - Longitudinal ventilation
KW - Maximum exceedance temperature
KW - Ramp slopes
UR - http://www.scopus.com/inward/record.url?scp=85141259204&partnerID=8YFLogxK
U2 - 10.1016/j.tust.2022.104829
DO - 10.1016/j.tust.2022.104829
M3 - Article
AN - SCOPUS:85141259204
SN - 0886-7798
VL - 131
JO - Tunnelling and Underground Space Technology
JF - Tunnelling and Underground Space Technology
M1 - 104829
ER -