Journal of Shanghai Jiao Tong University

Journal of Shanghai Jiaotong University >

2022 , Vol. 56 >Issue 6: 746 - 753

DOI: https://doi.org/10.16183/j.cnki.jsjtu.2021.062

Naval Architecture, Ocean and Civil Engineering

Quasi-Steady State Time Model of Fire Smoke Transmission in Long-Narrow Spaces

Expand
  • College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China

Received date: 2021-02-23

  Online published: 2022-07-04

Fold

Abstract

Transport time lag is a crucial characteristic of fire spreading in fire early stage, which determines the activation time of the fire detector. To clarify the quantitative relationship between the delay behavior and the quasi-steady state of smoke transmission in a long-narrow space, a time-varying spreadsheet is theoretically proposed to calculate the delay time of fire smoke transmission based on the theory of weak plume and the existing achievements concerned. Moreover, a theoretical model concerning the critical time for quasi-steady state assumption applicability is developed, where the method of calculating the critical time is also presented. The results of the case study show that due to the difference of smoke spreading velocity in long-narrow spaces and unconfined spaces for a case with the same conditions, the critical time for the smoke transmission to reach the quasi-steady state at a given radial distance on the ceiling in a long-narrow space is larger than that in the open space. For the open case, the thin ceiling plume, the small volume of entrained air, and the relatively high velocity of smoke lead to the longer delay time of smoke transmission in a long-narrow space than that in the open space under the same situations.

Key words： fire smoke; long-narrow space; lag; quasi-steady state model; critical time

Cite this article

WANG Jinhui, HUANG Yijun, CUI Xin, ZHANG Shaogang, ZHANG Ruiqing . Quasi-Steady State Time Model of Fire Smoke Transmission in Long-Narrow Spaces[J]. Journal of Shanghai Jiaotong University, 2022 , 56(6) : 746 -753 . DOI: 10.16183/j.cnki.jsjtu.2021.062

References

[1] HUANG D F, LI S C. An experimental investigation of stratification characteristic of fire smoke in the corridor under the effect of outdoor wind[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2018, 179: 173-183.
[2] 张聪, 李思成. 室外风与机械排烟综合作用下走廊烟气分层特性研究[J]. 消防科学与技术, 2019, 38(10): 1406-1411.
[2] ZHANG Cong, LI Sicheng. Combined effects of outdoor wind and mechanical smoke exhaust on smoke thermal stratification in corridor[J]. Fire Science and Technology, 2019, 38(10): 1406-1411.
[3] TIAN X L, LIU C, ZHONG M H. Numerical and experimental study on the effects of a ceiling beam on the critical velocity of a tunnel fire based on virtual fire source[J]. International Journal of Thermal Sciences, 2021, 159: 106635.
[4] 汪金辉, 焦宇, 许乐平. 船舶感烟探测器探测时间与布置间距近似计算[J]. 中国安全科学学报, 2011, 21(11): 67-71.
[4] WANG Jinhui, JIAO Yu, XU Leping. An approximate calculation method for response time and arrangement space of ship smoke detectors[J]. China Safety Science Journal, 2011, 21(11): 67-71.
[5] DELICHATSIOS M A. The flow of fire gases under a beamed ceiling[J]. Combustion and Flame, 1981, 43: 1-10.
[6] LIU C, ZHONG M H, TIAN X L, et al. Experimental and numerical study on fire-induced smoke temperature in connected area of metro tunnel under natural ventilation[J]. International Journal of Thermal Sciences, 2019, 138: 84-97.
[7] KOSLOWSKI C C, MOTEVALLI V. Effect of beams on ceiling jet behavior and heat detector operation[J]. Journal of Fire Protection Engineering, 1993, 5(3): 97-111.
[8] MOTEVALLI V, YUAN Z P. Steady state ceiling jet behavior under an unconfined ceiling with beams[J]. Fire Technology, 2008, 44(2): 97-112.
[9] OKA Y, OKA H. Velocity and temperature attenuation of a ceiling-jet along a horizontal tunnel with a flat ceiling and natural ventilation[J]. Tunnelling and Underground Space Technology, 2016, 56: 79-89.
[10] 汤静, 石必明, 陈昆. 典型结构走廊火灾烟气流场的数值模拟研究[J]. 中国安全生产科学技术, 2015, 11(10): 33-37.
[10] TANG Jing, SHI Biming, CHEN Kun. Numerical simulation of fire smoke flow in typical structure of building corridor[J]. Journal of Safety Science and Technology, 2015, 11(10): 33-37.
[11] 纪杰, 霍然, 张英, 等. 长通道内烟气层水平蔓延阶段的质量卷吸速率实验研究[J]. 中国科学技术大学学报, 2009, 39(7): 738-742.
[11] JI Jie, HUO Ran, ZHANG Ying, et al. Experimental study on the entrainment mass flow rate across the smoke layer interface during horizontal spread in a long channel[J]. Journal of University of Science and Technology of China, 2009, 39(7): 738-742.
[12] DAHANAYAKE K C, YANG Y Z, WAN Y, et al. Study on the fire growth in underground green corridors[J]. Building Simulation, 2020, 13(3): 627-635.
[13] KRÓL A, KRÓL M, KOPER P, et al. Numerical modeling of air velocity distribution in a road tunnel with a longitudinal ventilation system[J]. Tunnelling and Underground Space Technology, 2019, 91: 103003.
[14] 王浩波, 纪杰, 钟委, 等. 长通道内烟气一维水平蔓延阶段质量卷吸系数的实验研究[J]. 工程力学, 2009, 26(11): 247-251.
[14] WANG Haobo, JI Jie, ZHONG Wei, et al. Experimental study on air entrainment coefficient during one-dimensional horizontal movement of fire-induced smoke in long channels[J]. Engineering Mechanics, 2009, 26(11): 247-251.
[15] MOWRER F W. Lag times associated with fire detection and suppression[J]. Fire Technology, 1990, 26(3): 244-265.
[16] HESKESTAD G, DELICHATSIOS M A. Update: The initial convective flow in fire[J]. Fire Safety Journal, 1989, 15(6): 471-475.
[17] BEYLER C L. A design method for flaming fire detection[J]. Fire Technology, 1984, 20(4): 5-16.
[18] STROUP D W, EVANS D D. Use of computer fire models for analyzing thermal detector spacing[J]. Fire Safety Journal, 1988, 14(1/2): 33-45.
[19] ALPERT R L. Ceiling jet flows[M]∥SFPE handbook of fire protection engineering. New York, USA: Springer, 2016: 429-454.
[20] TANAKA T, FUJITA T, YAMAGUCHI J. Investigation into rise time of buoyant fire plume fronts[J]. International Journal of Engineering Performance-Based Fire Codes, 2000, 2(1): 14-25.
[21] HESKESTAD G. Rise of plume front from starting fires[J]. Fire Safety Journal, 2001, 36(2): 201-204.
[22] HU L H, LI Y Z, HUO R, et al. Experimental studies on the rise-time of buoyant fire plume fronts induced by pool fires[J]. Journal of Fire Sciences, 2004, 22(1): 69-86.
[23] 程远平, 陈亮, 张孟君. 火灾过程中火源热释放速率模型及其实验测试方法[J]. 火灾科学, 2002, 11(2): 70-125.
[23] CHENG Yuanping, CHEN Liang, ZHANG Mengjun. The models and experimental testing method of heat release rate of fuel during the development of fire[J]. Fire Safety Science, 2002, 11(2): 70-125.
[24] HESKESTAD G. Similarity relations for the initial convective flow generated by fire[R]. New York, USA: American Society of Mechanical Engineers, 1972.
[25] JOHN R. Smoke and heat extraction in large rooms[J]. VFDB-Zeitschrift Forschung, Technik and Management im Fire Protection, 1988, 38(1): 21-25.
[26] WANG J H, LI G Q, SHI L, et al. Transport time lag effect on smoke flow characteristics in long-narrow spaces[J]. Fire Technology, 2017, 53(3): 983-1010.
[27] BARENBLATT G I. Similarity, self-similarity, and intermediate asymptotics[M]. Boston, MA, USA: Springer, 1979.
Options
Outlines

/

〈 〉