Abstract：[Objective] Urban rail transit in China is developing rapidly due to the significant increase in subway lines and passenger flow. Although the subway system provides convenient transportation, the occurrence of subway car fires poses a potential risk to passengers. Subway cars are narrow and enclosed spaces, making them susceptible to significant property damage and casualties in the event of a fire. The existing research on subway car fires is primarily focused on natural ventilation conditions. Notably, subway cars are equipped with air supply systems to provide fresh air during normal operation, which continues to be operational during the initial stage of a fire. This air supply may considerably impact fire development and temperature distribution within the car during the fire. A clear understanding of the spreading of smoke and temperature distribution during subway car fires under air supply conditions can effectively determine the best position for fire detectors within the car. [Methods] This study establishes a comprehensive simulation model of a subway car. The car model comprises three main components: the passenger area, internal seating, and the top air supply system. The car includes four groups of air supply systems on the top. The length, width, and height of the car are 21.82, 2.92, and 1.86 m, respectively. After constructing the car model, we partition the grids and define the boundary conditions based on two ventilation scenarios: with and without a forced air supply. Further, two typical fire source locations—the center of the car and the area below the air supply outlet—and five different fire source powers are investigated. Analysis of this study primarily focuses on the airflow velocity distribution within the car under ventilation, and the temperature distribution within the car under the influence of air supply and different fire source positions. [Results] The results indicate that airflow vortexes are formed within the compartment when air is supplied, and the vortex position is directly related to the seating arrangement. The airflow velocity distribution within the compartment is significantly affected by the position of the air supply outlet. Under the experimental conditions, the presence or absence of ventilation within the compartment does not have a significant impact on the maximum temperature rise of the car ceiling. This may be attributed to the high temperature near the fire source, which results in significant thermal buoyancy. Hence, the air supply at the outlet does not affect the fire plume significantly. A stable smoke stratification may still occur during the car air supply, although the height of the smoke layer is considerably higher compared to natural ventilation. A strong correlation between the ceiling flue gas temperature and the position of the air supply outlet exists in the presence of the air supply. Each air supply outlet creates a low-temperature area, and the ceiling flue gas temperature at both ends of the compartment is significantly lower compared to natural ventilation. Furthermore, regardless of the presence or absence of an air supply, the smoke temperature on the compartment's ceiling decreases exponentially. [Conclusions] The findings of this research can serve as a reference for establishing subway car fire prevention strategies.
刘智远, 李行, 周汛. 送风环境下地铁车厢火灾温度分布[J]. 清华大学学报（自然科学版）, 2023, 63(10): 1529-1536.
LIU Zhiyuan, LI Xing, ZHOU Xun. Temperature distribution for fire in a forced ventilation subway car. Journal of Tsinghua University(Science and Technology), 2023, 63(10): 1529-1536.
[1] LEI W J, LI A G, TAI C M. The effect of different fire source locations on the environment of a subway station[J]. Procedia Engineering, 2017, 205:3721-3726. [2] YAN W Y, WANG J H, JIANG J C. Subway fire cause analysis model based on system dynamics:A preliminary model framework[J]. Procedia Engineering, 2016, 135:431-438. [3] ZHU P G, LIU C J, CHEN L, et al. Numerical simulation and measurement of fire ventilation in river-crossing tunnel[J]. Procedia Engineering, 2017, 205:153-159. [4] MENG N, WANG Q, LIU Z X, et al. Smoke flow temperature beneath tunnel ceiling for train fire at subway station:Reduced-scale experiments and correlations[J]. Applied Thermal Engineering, 2017, 115:995-1003. [5] 姜学鹏,肖倪琪,路世昌.不同车门开闭状态下地铁车厢火灾特性研究[J].消防科学与技术, 2021, 40(1):76-81. JIANG X P, XIAO N Q, LU S C. Fire characteristics of metro cabin under different doors opening and closing conditions[J]. Fire Science and Technology, 2021, 40(1):76-81.(in Chinese) [6] SHI C L, ZHONG M H, CHEN C K, et al. Metro train carriage combustion behaviors:Full-scale experiment study[J]. Tunnelling and Underground Space Technology, 2020, 104:103544. [7] 覃道枞,郭兵,周健,等.不同通风条件下车厢火灾烟气运动的数值模拟研究[J].工业安全与环保, 2020, 46(10):29-33. QIN D C, GUO B, ZHOU J, et al. Numerical simulation of smoke movement in train compartment fire under different ventilation conditions[J]. Industrial Safety and Environmental Protection, 2020, 46(10):29-33.(in Chinese) [8] 姚勇征,张少刚,朱凯,等.地铁车厢火灾时顶棚下最高温升研究[C]//2015消防工程技术国际学术研讨会论文集.天津:天津大学出版社, 2015:19-31. YAO Y Z, ZHANG S G, ZHU K, et al. Maximum temperature rise beneath ceiling in a subway carriage fire[C]//Proceedings of 2015 International Symposium on Fire Engineering Technology. Tianjin:Tianjin University Press, 2015:19-31.(in Chinese) [9] 李娜,张艳,华宇东,等.外界风场对高铁车厢行李火灾发展的影响[J].中国安全科学学报, 2020, 30(12):141-147. LI N, ZHANG Y, HUA Y D, et al. Impact of external wind field on spread of luggage fire in high-speed rail carriage[J]. China Safety Science Journal, 2020, 30(12):141-147.(in Chinese) [10] 丁厚成,戚文竟,朱志伟,等.地铁车厢内部火灾烟气流动规律的数值模拟研究[J].安全与环境工程, 2017, 24(4):123-128. DING H C, QI W J, ZHU Z W, et al. Research on numerical simulation of air and smoke flow regularity in subway carriage fire[J]. Safety and Environmental Engineering, 2017, 24(4):123-128.(in Chinese) [11] 彭敏.侧向多开口地铁列车车厢火灾燃烧特性研究[D].合肥:中国科学技术大学, 2021. PENG M. Study on combustion characteristics of fires inside subway train with multiple lateral openings[D]. Hefei:University of Science and Technology of China, 2021.(in Chinese) [12] 席亚军,林建辉,苏燕辰,等.地铁车厢火灾蔓延规律及人员疏散安全性研究[J].铁道科学与工程学报, 2017, 14(3):619-625. XI Y J, LIN J H, SU Y C, et al. Subway car fire spreading rules and evacuation safety studies[J]. Journal of Railway Science and Engineering, 2017, 14(3):619-625.(in Chinese) [13] 徐志胜,王悦琳,赵家明,等.市域快线列车内不同位置火灾对隧道温度场分布的影响研究[J/OL].铁道科学与工程学报:1-10[2023-04-06] . https://doi.org/10.19713/j.cnki.43-1423/u.T20221774. XU Z S, WANG Y L, ZHAO J M, et al. Research on the influence of fire at different positions in the metropolitan rapid rail transit vehicle on the temperature field distribution of the tunnel[J/OL]. Journal of Railway Science and Engineering:1-10[2023-04-06] . https://doi.org/10.19713/j.cnki.43-1423/u.T20221774.(in Chinese) [14] 周丹,唐子童,胡天恩,等.隧道半径对地铁列车火灾烟气蔓延特性影响研究[J/OL].铁道科学与工程学报:1-10[2023-04-06] . https://doi.org/10.19713/j.cnki.43-1423/u.T 20222003. ZHOU D, TANG Z T, HU T E, et al. Research on effect of tunnel radius on smoke movement characteristics in subway trains fire[J/OL]. Journal of Railway Science and Engineering:1-10[2023-04-06] . https://doi.org/10.19713/j.cnki.43-1423/u.T20222003.(in Chinese) [15] 李冬,苏燕辰,田鑫,等. B型地铁列车火灾安全疏散性能研究[J].铁道科学与工程学报, 2016, 13(8):1613-1617. LI D, SU Y C, TIAN X, et al. Research on the evacuation performance of B-type subway train in the condition of fire disaster[J]. Journal of Railway Science and Engineering, 2016, 13(8):1613-1617.(in Chinese) [16] 中华人民共和国住房和城乡建设部,中华人民共和国国家质量监督检验检疫总局.地铁设计规范:GB 50157-2013[S].北京:中国建筑工业出版社, 2014. Ministry of Housing and Urban-Rural Development of the People's Republic of China, General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. Metro design guidelines:GB 50157-2013[S]. Beijing:China Architecture&Building Press, 2014.(in Chinese) [17] ZHAO D Y, CHEN C K, LEI P, et al. Experimental study on temperature profile and smoke movement in a model-branched tunnel fire under longitudinal ventilation[J]. Tunnelling and Underground Space Technology, 2022, 121:104324.
2023, Vol. 63 
