基于大涡模拟的油池火焰瞬态辐射传热研究

doi:10.16265/j.cnki.issn1003-3033.2022.04.010

摘要/Abstract

摘要：

为探究油池火焰燃烧过程中火焰辐射的瞬态辐射传热特性,基于大涡模拟方法建立甲醇油池火焰的燃烧模型,并采用准确性高的灰气体加权和模型 (WSGG) 模拟高温气体非灰辐射特性;研究甲醇火焰瞬态燃烧过程中的温度、速度、组分浓度变化及辐射热量的瞬态分布特性。结果表明:燃烧气体温度呈现周期性的变化,会不断地有高温气体在油池表面生成,然后上升、膨胀扩散,且在上升过程中气体速度先变大后减小。受此影响,池火液面受到的辐射热反馈随时间剧烈震荡,液面中心辐射热流密度在-17 ~ -7 kW/m²之间变化,且向液面边缘逐渐减小;液面的热流密度概率密度分布呈现三角形;地面的辐射热量因为距离火焰较远及油罐的遮挡作用,比液面小一个数量级。

关键词: 油池火, 大涡模拟, 甲醇火焰, 辐射传热, 瞬态辐射热流密度

Abstract:

In order to explore transient radiative heat transfer characteristics of pool fires, a combustion model of methanol fire was developed based on large eddy simulation, and non-gray radiative properties of combustion gases were simulated by adopting accurate weighted sum of gray gases (WSGG) model. Then, transient characteristics of temperature, velocity, species concentration and radiative energy were investigated. The results show that gas temperature varies in a periodical pattern, during which high temperature gases form above pool surface, then rises, expands and spreads in cycles, with its velocity increasing first and then decreasing during rising process. Due to this factor, radiative feedback at surface shows an oscillating behavior, and radiative heat flux at center varies between -17 and -7 kW/m² drastically, which decreases along radial direction. Moreover, probability density of heat fluxes at surface spreads like a triangle. As the ground is far away from fire and partially blocked by tanks, its heat flux is one order of magnitude smaller that of pool surfaces.

Key words: pool fire, large eddy simulation, methanol fire, radiative heat transfer, transient radiative heat flux

孙玉佳. 基于大涡模拟的油池火焰瞬态辐射传热研究[J]. 中国安全科学学报, 2022, 32(4): 65-71.

SUN Yujia. Transient radiative heat transfer of pool fires based on large eddy simulation[J]. China Safety Science Journal, 2022, 32(4): 65-71.

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参考文献 22

[1]	黄勇, 张红伟, 申荣艳, 等. 抑爆柴油池火燃烧特性试验研究[J]. 中国安全科学学报, 2019, 29(8): 55-60. doi: 10.16265/j.cnki.issn1003-3033.2019.08.009
	HUANG Yong, ZHANG Hongwei, SHEN Rongyan, et al. Experimental study on pool fire combustion characteristics of explosion suppression diesel fuel[J]. China Safety Science Journal, 2019, 29(8): 55-60. doi: 10.16265/j.cnki.issn1003-3033.2019.08.009
[2]	陈福真, 张明广, 王妍, 等. 罐区池火灾多米诺效应试验研究[J]. 中国安全科学学报, 2017, 27(11): 31-36. doi: 10.16265/j.cnki.issn1003-3033.2017.11.006
	CHEN Fuzhen, ZHANG Mingguang, WANG Yan, et al. Experimental study on domino effect in pool fire in tank farm[J]. China Safety Science Journal, 2017, 27(11): 31-36. doi: 10.16265/j.cnki.issn1003-3033.2017.11.006
[3]	侯志强, 陈梓松. 多米诺效应对港口油品储罐事故概率的影响[J]. 中国安全科学学报, 2020, 30(9): 59-65.
	HOU Zhiqiang, CHEN Zisong. Influence of domino effect on accident probability of oil storage tanks in ports[J]. China Safety Science Journal, 2020, 30(9): 59-65.
[4]	庄磊, 陈国庆, 孙志友, 等. 大型油罐火灾的热辐射危害特性[J]. 安全与环境学报, 2008, 8(4): 110-114.
	ZHUANG Lei, CHEN Guoqing, SUN Zhiyou, et al. On the damage study of the thermal radiation of the large oil-tank fire accidents[J]. China Safety Science Journal, 2008, 8(4): 110-114.
[5]	傅智敏, 黄晓哲, 李元梅. 烃类池火灾热辐射量化分析模型探讨[J]. 中国安全科学学报, 2010, 20(8): 65-70.
	FU Zhimin, HUANG Xiaozhe, LI Yuanmei. Discussion on thermal radiation flux model for hydrocarbon pool fires[J]. China Safety Science Journal, 2010, 20(8): 65-70.
[6]	魏东, 杨君涛, 董希琳. 着火油罐稳定燃烧时的辐射热分布[J]. 热科学与技术, 2005, 4(3): 241-245.
	WEI Dong, YANG Juntao, DONG Xilin. Thermal radiation distribution of steady burning of oil tank[J]. Journal of Thermal Science and Technology, 2005, 4(3): 241-245.
[7]	张媛媛, 黄有波, 吕淑然. 矩形泄漏孔水平喷射火热辐射研究[J]. 中国安全科学学报, 2017, 27(6): 73-78. doi: 10.16265/j.cnki.issn1003-3033.2017.06.013
	ZHANG Yuanyuan, HUANG Youbo, LYU Shuran. Study on thermal radiation of horizontally oriented rectangular source fuel jet fire[J]. China Safety Science Journal, 2017, 27(6): 73-78. doi: 10.16265/j.cnki.issn1003-3033.2017.06.013
[8]	刘全义, 朱博, 邓力, 等. 低压环境下不同直径油池火特征参量研究[J]. 中国安全科学学报, 2021, 31(4): 105-110. doi: 10.16265/j.cnki.issn1003-3033.2021.04.014
	LIU Quanyi, ZHU Bo, DENG Li, et al. Study on characteristic parameters of oil pool fire of different diameters in low pressure environment[J]. China Safety Science Journal, 2021, 31(4): 105-110. doi: 10.16265/j.cnki.issn1003-3033.2021.04.014
[9]	王坚, 王伟, 杨锐, 等. 高高原机场油池火燃烧特性研究[J]. 中国安全科学学报, 2017, 27(10): 62-67. doi: 10.16265/j.cnki.issn1003-3033.2017.10.011
	WANG Jian, WANG Wei, YANG Rui, et al. High plateau airport pool fire combustion characteristic research[J]. China Safety Science Journal, 2017, 27(10): 62-67. doi: 10.16265/j.cnki.issn1003-3033.2017.10.011
[10]	JI Jie, GONG Changzhiu, WAN Huaxian, et al. Prediction of thermal radiation received by vertical targets based on two-dimensional flame shape from rectangular n-heptane pool fires with different aspect ratios[J]. Energy, 2019, 185: 644-652. doi: 10.1016/j.energy.2019.07.083
[11]	LIU Jiahao, ZHOU Zhihui. Examination of radiative fraction of small-scale pool fires at reduced pressure environments[J]. Fire Safety Journal, 2019, 110: DOI: 10.1016/j.firesaf.2019.102894. doi: 10.1016/j.firesaf.2019.102894
[12]	GUO Qi, ROOT K J, CARLTON A, et al. Framework for rapid prediction of fire-induced heat flux on concrete tunnel liners with curved ceilings[J]. Fire Safety Journal, 2019, 109: DOI: 10.1016/j.firesaf.2019.102866. doi: 10.1016/j.firesaf.2019.102866
[13]	SHI Congling, LIU Wei, HONG Wenjie, et al. A modified thermal radiation model with multiple factors for investigating temperature rise around pool fire[J]. Journal of Hazardous Materials, 2019, 379: DOI: 10.1016/j.jhazmat.2019.120801. doi: 10.1016/j.jhazmat.2019.120801
[14]	MA Li, NMIRA F, CONSALVI J L. Large Eddy Simulation of medium-scale methanol pool fires-effects of pool boundary conditions[J]. Combustion and Flame, 2020, 222: 336-354. doi: 10.1016/j.combustflame.2020.09.007
[15]	WU Bifen, ROY S P, ZHAO Xinyu. Detailed modeling of a small-scale turbulent pool fire[J]. Combustion and Flame, 2020, 214: 224-237. doi: 10.1016/j.combustflame.2019.12.034
[16]	XU Rui, LE V M, MARCHAND A, et al. Simulations of the coupling between combustion and radiation in a turbulent line fire using an unsteady flamelet model[J]. Fire Safety Journal, 2021, 120: DOI: 10.1016/j.fresaf.2020.103101. doi: 10.1016/j.fresaf.2020.103101
[17]	FRAGA G C, COELHO P J, FRANÇA F H R. Assessing individual time-averaged emission and absorption correlations for large-scale turbulent pool fires[J]. International Journal of Heat and Mass Transfer, 2021, 165: DOI: 10.1016/j.ijheatmasstransfer.2020.120665. doi: 10.1016/j.ijheatmasstransfer.2020.120665
[18]	CHU Huaqiang, LIU Fengshan, ZHOU Huaichun. Calculations of gas radiation heat transfer in a two-dimensional rectangular enclosure using the line-by-line approach and the statistical narrow-band correlated-k model[J]. International Journal of Thermal Sciences, 2012, 59: 66-74. doi: 10.1016/j.ijthermalsci.2012.04.003
[19]	MARAGKOS G, BEJI T, MERCI B. Towards predictive simulations of gaseous pool fires[J]. Proceedings of the Combustion Institute, 2019, 37(3): 3927-3934. doi: 10.1016/j.proci.2018.05.162
[20]	VERMESI I, DIDOMIZIO M J, RICHTER F, et al. Pyrolysis and spontaneous ignition of wood under transient irradiation: experiments and a-priori predictions[J]. Fire Safety Journal, 2017, 91: 218-225. doi: 10.1016/j.firesaf.2017.03.081
[21]	HOWELL J R, MENGUC M P, SIEGEL R. Thermal radiation heat transfer, 5th edition[M]. Boca Raton: CRC Press, 2010: 619-710.
[22]	AHMED M, TROUVE A. Large eddy simulation of the unstable flame structure and gas-to-liquid thermal feedback in a medium-scale methanol pool fire[J]. Combustion and Flame, 2021, 225: 237-254. doi: 10.1016/j.combustflame.2020.10.055