Research on influence of shaft incline angle and ambient pressure on smoke plug-holing

doi:10.16265/j.cnki.issn1003-3033.2025.08.1341

Abstract

Abstract:

To better design the smoke exhaust system for tunnel shafts in high-altitude areas, numerical simulation methods were used to calculate and analyze the effects of environmental pressure and shaft inclination angle on the smoke plug-holing effect during tunnel fires. The temperature fields under different working conditions were obtained using FDS simulations. The plug-holing height was introduced to determine the degree of plug-holing for each working condition. Combined with the degree of plug-holing, the dimensionless Richardson number (Ri') was redefined, and a theoretical calculation model for the plug-holing height was proposed. The critical Ri' number (Ri_c') for the occurrence of plug-holing was derived. The results show that the plug-holing height increases with the increase of the angle and environmental pressure. The Ri' number decreases with the decrease of environmental pressure and increases with the increase of the shaft inclination angle. Under the same environmental pressure, Ri_c' number decreases with the increase of the shaft inclination angle. The relationship between Ri' number and the Ri_c' number can be used to determine whether a complete plug-holing effect occurs.

Key words: shaft inclined angle, environmental pressure, plug-holing effect, plug-holing height, tunnel fire

CLC Number:

X932爆炸安全与防火、防爆

TANG Junlei, LI Yuanzhou. Research on influence of shaft incline angle and ambient pressure on smoke plug-holing[J]. China Safety Science Journal, 2025, 35(8): 180-187.

Figures/Tables 15

Fig.1

Table 1

Fig.2

Fig.3

Fig.4

Table 2

Table 3

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Table 4

References 24

[1]	王启睿, 姜学鹏, 薛光桥, 等. 我国公路隧道火灾社会风险可接受标准研究[J]. 中国安全科学学报, 2024, 34(4): 121-127. doi: 10.16265/j.cnki.issn1003-3033.2024.04.0687
	WANG Qirui, JIANG Xuepeng, XUE Guangqiao, et al. Study on social risk acceptance criteria of road tunnel fire in China[J]. China Safety Science Journal, 2024, 34(4): 121-127. doi: 10.16265/j.cnki.issn1003-3033.2024.04.0687
[2]	高子鹤. 隧道内受限火羽流行为特征及竖井自然排烟机理研究[D]. 合肥: 中国科学技术大学, 2016.
	GAO Zihe. Studies on characteristics of confined fire plumes and mechanism of natural smoke exhaust by shaft[D]. Hefei: University of Science and Technology of China, 2016.
[3]	JI Jie, GUO Fangyi, GAO Zihe, et al. Numerical investigation on the effect of ambient pressure on smoke movement and temperature distribution in tunnel fires[J]. Applied Thermal Engineering, 2017, 118: 663-669.
[4]	YAN Zhiguo, GUO Qinghua, ZHU Hehua. Full-scale experiments on fire characteristics of road tunnel at high altitude[J]. Tunnelling and Underground Space Technology, 2017, 66: 134-146.
[5]	张念, 谭忠盛. 高海拔特长铁路隧道火灾烟气分布特性数值模拟研究[J]. 中国安全科学学报, 2013, 23(6): 52-57.
	ZHANG Nian, TAN Zhongsheng. Numerical simulation study on smoke distribution of fire in high-altitude super-long railway tunnels[J]. China Safety Science Journal, 2013, 23(6): 52-57.
[6]	张念, 谭忠盛, 毛军, 等. 高海拔铁路隧道火灾燃烧特性试验研究[J]. 中国安全科学学报, 2011, 21(12): 52-57.
	ZHANG Nian, TAN Zhongsheng, MAO Jun, et al. Experimental study on combustion characteristics of fire in high-altitude railway tunnels[J]. China Safety Science Journal, 2011, 21(12): 52-57.
[7]	纪慧琢. 高海拔特长隧道火灾烟气流动特性的数值模拟分析[D]. 北京: 北京交通大学, 2010.
	JI Huizhuo. The simulation and analysis of fire smoke of extra long tunnel in high altitude region[D]. Beijing: Beijing Jiaotong University, 2010.
[8]	田源. 高海拔隧道火灾烟气及温度场数值模拟研究[J]. 消防科学与技术, 2021, 40(2): 201-203.
	TIAN Yuan. Numerical simulation of fire smoke and temperature field in high altitude tunnel[J]. Fire Science and Technology, 2021, 40(2): 201-203.
[9]	杜涛, 李萍, 王雨, 等. 隧道火灾烟气温度及蔓延速度衰减特性[J]. 中国安全科学学报, 2023, 33(2): 140-145. doi: 10.16265/j.cnki.issn1003-3033.2023.02.0399
	DU Tao, LI Ping, WANG Yu, et al. Longitudinal decay of smoke temperature and front velocity in tunnel fires[J]. China Safety Science Journal, 2023, 33(2): 140-145. doi: 10.16265/j.cnki.issn1003-3033.2023.02.0399
[10]	XUE Dapeng, ZHENG Guoping, GUO Hongyu, et al. Study on the reasonable tilt angle of ventilation shafts in Xidianwan tunnel, China[J]. IOP Conference Series: Earth and Environmental Science, 2020, 601: DOI: 10.1088/1755-1315 /601/1/012003.
[11]	YAO Yongzheng, ZHANG Shaogang, SHI Long, et al. Effects of shaft inclination angle on the capacity of smoke exhaust under tunnel fire[J]. Indoor and Built Environment, 2019, 28(1): 77-87. doi: 10.1177/1420326X17734906
[12]	樊勇杰. 低压环境下竖井自然排烟隧道火灾烟气特性研究[D]. 武汉: 武汉科技大学, 2022.
	FAN Yongjie. Study on the fire smoke characteristics of the natural smoke extraction tunnel with vertical shaft at reduced ambient pressure[D]. Wuhan: Wuhan University of Science and Technology, 2022.
[13]	梁建兴. 排烟井倾角对竖井隧道火灾烟气热分层和运动影响研究[D]. 绵阳: 西南科技大学, 2023.
	LIANG Jianxing. Study of the effect of smoke shaft inclination on the thermal stratification and movement of smoke from shaft tunnel fire[D]. Mianyang: Southwest University of Science and Technology, 2023.
[14]	黄天荣, 张银屏, 宋飞. 自然通风隧道不同竖井结构形式火灾试验研究[J]. 消防科学与技术, 2020, 39(10): 1376-1379.
	HUANG Tianrong, ZHANG Yinping, SONG Fei. Fire tests of different shaft structures in natural ventilation tunnel[J]. Fire Science and Technology, 2020, 39(10): 1376-1379.
[15]	YAN Guanfeng, WANG Mingnian, YU Li, et al. Effects of ambient pressure on smoke movement patterns in vertical shafts in tunnel fires with natural ventilation systems[J]. Building Simulation, 2020, 13(4): 931-941.
[16]	JTG/T D70/2-02-2014,公路隧道通风设计细则[S].
	JTG/T D70/2-02-2014,Guidelines for design of ventilation of highway tunnels[S].
[17]	MCGRATTAN K B, MCDERMOTT R J, WEINSCHENK C G, et al. Fire dynamics simulator: technical reference guide: sixth edition:1018[R]. Gaithersburg: National Institute of Standards and Technology, 2024.
[18]	CONG Haiyong, WANG Xinshi, ZHU Pei, et al. Improvement in smoke extraction efficiency by natural ventilation through a board-coupled shaft during tunnel fires[J]. Applied Thermal Engineering, 2017, 118: 127-137.
[19]	COOPER L Y, HARKLEROAD M, QUINTIERE J, et al. An experimental study of upper hot layer stratification in full-scale multiroom fire scenarios[J]. Journal of Heat and Mass Transfer, 1982, 104(4): 741-749.
[20]	JI Jie, GAO Zihe, FAN Chuangang, et al. A study of the effect of plug-holing and boundary layer separation on natural ventilation with vertical shaft in urban road tunnel fires[J]. International Journal of Heat and Mass Transfer, 2012, 55(21/22): 6032-6041.
[21]	霍然, 胡源, 李元洲. 建筑火灾安全工程导论[M]. 合肥: 中国科学技术大学出版社, 2009: 98-99.
	HUO Ran, HU Yuan, LI Yuanzhou. Introduction to building fire safety engineering[M]. Hefei: University of Science and Technology of China Press, 2009: 98-99.
[22]	张靖岩, 李元洲, 霍然, 等. 竖井中羽流前锋上升时间的实验研究[J]. 安全与环境学报, 2006, 6(2): 111-114.
	ZHANG Jingyan, LI Yuanzhou, HUO Ran, et al. Experimental study on the rising-time of fire plume fronts in the vertical shaft[J]. Journal of Safety and Environment, 2003, 6(2): 111-114.
[23]	刘紫玮, 唐飞, 胡隆华, 等. 不同低气压环境下走廊火灾顶棚射流温度分布特征研究[J]. 工程热物理学报, 2024, 45(7): 2166-2174.
	LIU Ziwei, TANG Fei, HU Longhua, et al. Temperature profile characteristics of ceiling jet in corridor fires under various sub-atmospheric pressures[J]. Journal of Engineering Thermophysics, 2024, 45(7): 2166-2174.
[24]	WANG Zhan, DENG Wenhui, ZHOU Min, et al. Evaluation of fire smoke and heat exhaust performance of shafts by natural venting in tunnels[J]. Tunnelling and Underground Space Technology, 2023, 131: DOI: 10.1016/J.TUST.2022.104817.

工况	θ/(°)
1—2	0
3—4	30
5—6	45
7—8	60
9—10	75
11—12	90

θ/(°)	P_a/kPa
θ/(°)	65	100
30	未吸穿	未吸穿
45	未吸穿	临界状态
60	吸穿	吸穿
75	吸穿	吸穿
90	吸穿	吸穿

P_a/kPa	烟气厚度/m	烟气速度/(m·s^-1)	烟气密度/(kg·m^-3)	环境密度/(kg·m^-3)	Ri'	Ri_c'
65	2.71	1.92	0.64	1.17	2.79	1.1^[12]
100	2.60	1.54	1.03	0.76	3.16	1.4^[20]

P_a/kPa	60	70	80	90	100
文献[12]经验值	1.1	1.2	1.3	1.3	1.4
理论模型计算值	1.1	1.2	1.2	1.2	1.3