Disaster effects of combustible gas explosion in an urban shallow-buried pipe trench (Ⅰ): shock wave propagation on the ground
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摘要: 城市地下浅埋管沟燃气爆炸事故会造成严重的灾害后果,然而目前针对长直空间内的爆炸荷载通过泄爆口向外传播规律的研究较少。以此类事故为基础,基于前期进行的长直泄爆空间可燃气体爆炸试验,利用FLACS软件,对城市地下浅埋管沟内可燃气体爆炸冲击波超压通过泄爆口到达地面后的分布进行了数值模拟,揭示了管沟内燃气爆炸冲击波在地面的传播规律。结果表明:传播到地面的爆炸冲击波会产生2个特征超压峰值Δp1和Δp2;Δp1较小,主要由压缩波引起,Δp2为最大超压峰值,主要由火焰波引起;Δp2随着与泄爆口之间的距离d的增大而逐渐减小,且各方向上数值的差异性较大,其中在沿管沟截面的短边方向上,呈对称衰减的趋势;Δp2与d大致满足指数函数关系,且拟合度均高于98.8%。Abstract: The blast shock wave will be transmitted to the ground through the vent as a gas explosion accident occurs in an urban shallowly-buried pipe trench, and cause serious disaster consequences. However, there are few studies on the propagating law of the explosion load outward through the explosion vent in the long and straight space. Thus, it is necessary to reveal the explosion load distribution law on the ground of such accidents. Based on the combustible gas explosion test in the long and straight venting space conducted in the previous period, the applicability of parameters and grid size in FLACS software were verified. Then the FLACS software was used to carry out numerical simulations of the gas explosion process in the urban shallow buried pipe trench. The propagation process of shock wave was divided into three stages: stable stage, Δp1 stage and Δp2 stage, and the mechanism of shock wave was analyzed by fuel, flame, flow velocity and density. The results show that the value of Δp1 is small, mainly caused by compression waves, and Δp2 is the maximum overpressure peak, mainly caused by flame waves. The characteristics of the overpressure time-history curve were studied. The results show that Δp1 has smaller differences in each direction than Δp2, and the wave propagation has obvious directionality in X and Z directions, while symmetrical in the y direction. The attenuation law of shock waves in space was studied and the attenuation formula in each direction was obtained by data fitting. The results show that Δp2 gradually decreases with the increase of the distance from the venting port, and the value of the value in each direction varies greatly, among which, it shows a symmetrical attenuation trend along the short side of the pipe trench section; Δp2 and distance roughly satisfy the exponential function relationship, and the fitting degree is above 98.8%.
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表 1 管沟可燃气体爆炸工况记录
Table 1. Working condition record of combustible gas explosion in pipe trench
工况 泄爆口位置 顶部泄爆口数目 甲烷体积分数/% 1-A 尾部+顶部 3 7.5 1-B 尾部+顶部 3 8.5 1-C 尾部+顶部 3 9.5 1-D 尾部+顶部 3 10.5 1-E 尾部+顶部 3 11.5 2-C 密闭,无泄爆口 0 9.5 3-C 尾部 0 9.5 表 2 测点的坐标
Table 2. Coordinates of measuring points
X 轴方向 Y 轴方向 Z 轴方向 测点 坐标/m 测点 坐标/m 测点 坐标/m X1 (25,0,1) Y1 (44.5,−10,1) Z1 (44.5,0,1) X2 (30,0,1) Y2 (44.5,−7,1) Z2 (44.5,0,2) X3 (35,0,1) Y3 (44.5,−5,1) Z3 (44.5,0,3) X4 (40,0,1) Y4 (44.5,−4,1) Z4 (44.5,0,4) X5 (41,0,1) Y5 (44.5,−3,1) Z5 (44.5,0,5) X6 (42,0,1) Y6 (44.5,−2,1) Z6 (44.5,0,6) X7 (43,0,1) Y7 (44.5,−1,1) Z7 (44.5,0,7) X8 (46,0,1) Y8 (44.5,1,1) Z8 (44.5,0,8) X9 (47,0,1) Y9 (44.5,2,1) Z9 (44.5,0,9) X10 (48,0,1) Y10 (44.5,3,1) Z10 (44.5,0,10) X11 (49,0,1) Y11 (44.5,4,1) Z11 (44.5,0,11) X12 (54,0,1) Y12 (44.5,5,1) Z12 (44.5,0,13) X13 (59,0,1) Y12 (44.5,7,1) Z12 (44.5,0,16) X14 (64,0,1) Y12 (44.5,10,1) Z12 (44.5,0,20) -
[1] 中华人民共和国住房和城乡建设部. 2019年城市建设统计年鉴 [EB/OL]. (2020-12-31)[2021-10-08]. https://www.mohurd.gov.cn/file/old/2020/20201231/w02020123122485271423125000.xls. [2] ZHU Y, QIAN X M, LIU Z Y, et al. Analysis and assessment of the Qingdao crude oil vapor explosion accident: Lessons learnt [J]. Journal of Loss Prevention in the Process Industries, 2015, 33: 289–303. DOI: 10.1016/j.jlp.2015.01.004. [3] YANG H N, CHEN J H, CHIU H J, et al. Confined vapor explosion in Kaohsiung City: a detailed analysis of the tragedy in the Harbor City [J]. Journal of Loss Prevention in the Process Industries, 2016, 41: 107–120. DOI: 10.1016/j.jlp.2016.03.017. [4] 王东武, 杜春志. 巷道瓦斯爆炸传播规律的试验研究 [J]. 采矿与安全工程学报, 2009, 26(4): 475–480, 485. DOI: 10.3969/j.issn.1673-3363.2009.04.017.WANG D W, DU C Z. Experimental study on gas explosion and propagation in a test gallery [J]. Journal of Mining and Safety Engineering, 2009, 26(4): 475–480, 485. DOI: 10.3969/j.issn.1673-3363.2009.04.017. [5] 司荣军. 管道内瓦斯爆炸传播试验研究 [J]. 煤炭科学技术, 2009, 37(2): 47–49; 123. DOI: 10.13199/j.cst.2009.02.52.sirj.022.SI R J. Test and research on gas explosion transmission in pipeline [J]. Coal Science and Technology, 2009, 37(2): 47–49; 123. DOI: 10.13199/j.cst.2009.02.52.sirj.022. [6] MA H Y, ZHONG M S, LI X H, et al. Experimental and numerical simulation study on the shock and vibration effect of OD1422-X80 mainline natural gas pipeline explosion [J]. Shock and Vibration, 2019, 2019: 6824819. DOI: 10.1155/2019/6824819. [7] CICCARELLI G, JOHANSEN C T, PARRAVANI M. The role of shock-flame interactions on flame acceleration in an obstacle laden channel [J]. Combustion and Flame, 2010, 157(11): 2125–2136. DOI: 10.1016/j.combustflame.2010.05.003. [8] NA’INNA A M, PHYLAKTOU H N, ANDREWS G E. Explosion flame acceleration over obstacles: effects of separation distance for a range of scales [J]. Process Safety and Environmental Protection, 2017, 107: 309–316. DOI: 10.1016/j.psep.2017.01.019. [9] 孙庆文. 城市综合管廊内天然气爆炸荷载特性研究 [D]. 北京: 北京工业大学, 2018: 15–33.SUN Q W. Study on the characteristics of gas explosion load in urban utility tunnel [D]. Beijing, China: Beijing University of Technology, 2018: 15–33. [10] HOU L F, LI Y Z, QIAN X M, et al. Large-scale experimental investigation of the effects of gas explosions in underdrains [J]. Journal of Safety Science and Resilience, 2021, 2(2): 90–99. DOI: 10.1016/j.jnlssr.2021.03.001. [11] 宫广东, 刘庆明, 白春华. 管道中瓦斯爆炸特性的数值模拟 [J]. 兵工学报, 2010, 31(S1): 17–21.GONG G D, LIU Q M, BAI C H. Numerical simulation for gas explosion in tubes [J]. Acta Armamentarii, 2010, 31(S1): 17–21. [12] 龚燚. 燃气管线入综合管廊的抗爆防护技术研究 [D]. 南京: 南京理工大学, 2018: 17–36.GONG Y. Research on anti-explosion protection technology of gas pipeline entering the comprehensive pipe gallery [D]. Nanjing, Jiangsu, China: Nanjing University of Science and Technology, 2018: 17–36. [13] 董浩宇. 地下综合管廊燃气爆炸灾害效应时空演化规律及防控策略 [D]. 广州: 华南理工大学, 2020: 25–35. DOI: 10.27151/d.cnki.ghnlu.2020.004461.DONG H Y. Law of temporal and spatial evolution of gas explosion hazard and prevention and controlling in utility tunnel [D]. Guangzhou, Guangdong, China: South China University of Technology, 2020: 25–35. DOI: 10.27151/d.cnki.ghnlu.2020.004461. [14] 刘洋, 李展, 方秦, 等. 惰性气体和水蒸气对长直空间燃气爆炸超压及其振荡的抑制作用 [J]. 高压物理学报, 2021, 35(5): 055201. DOI: 10.11858/gywlxb.20200654.LIU Y, LI Z, FANG Q, et al. Inert gas and water vapor suppressing overpressure and its oscillation of gas explosion in long straight space [J]. Chinese Journal of High Pressure Physics, 2021, 35(5): 055201. DOI: 10.11858/gywlxb.20200654. [15] 陈晓坤, 郭丽萍, 程方明, 等. 独头巷道瓦斯爆炸的数值模拟 [J]. 煤矿安全, 2012, 43(7): 20–22. DOI: 10.13347/j.cnki.mkaq.2012.07.058.CHEN X K, GUO L P, CHENG F M, et al. Numerical simulation of gas explosion in heading face [J]. Safety in Coal Mines, 2012, 43(7): 20–22. DOI: 10.13347/j.cnki.mkaq.2012.07.058. [16] 王涛. 管道内甲烷爆炸特性及CO2抑爆的实验与数值模拟研究 [D]. 西安: 西安科技大学, 2014: 25–49.WANG T. Experimental and numerical studies on methane explosion and the suppression effect of CO2 in vessel [D]. Xi’an, Shaanxi, China: Xi’an University of Science and Technology, 2014: 25–49. [17] HISKEN H, ENSTAD G A, MIDDHA P, et al. Investigation of concentration effects on the flame acceleration in vented channels [J]. Journal of Loss Prevention in the Process Industries, 2015, 36: 447–459. DOI: 10.1016/j.jlp.2015.04.005. [18] ZHANG S H, MA H T, HUANG X M, et al. Numerical simulation on methane-hydrogen explosion in gas compartment in utility tunnel [J]. Process Safety and Environmental Protection, 2020, 140: 100–110. DOI: 10.1016/j.psep.2020.04.025. [19] YANG Y, YANG S G, FANG Q, et al. Large-scale experimental and simulation study on gas explosion venting load characteristics of urban shallow buried pipe trenches [J]. Tunnelling and Underground Space Technology, 2022, 123: 104409. DOI: 10.1016/j.tust.2022.104409. [20] 中国建筑标准设计研究院. 市政排水管道工程及附属设施: 06MS201 [S]. 北京: 中国计划出版社, 2007.China Building Standard Design and Research Institute. Municipal drainage pipeline engineering and ancillary facilities: 06MS201 [S]. Beijing: China Planning Press, 2007.