火场条件下相邻汽油罐油蒸汽泄漏及爆炸规律
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摘要
油库发生火灾时,临近的油罐内汽油受热形成油蒸汽从呼吸阀泄出,泄漏的油蒸汽与空气混合易点燃,易引起燃烧爆炸事故。本文中以容积为5 000 m~3(?22 m×13 m)的汽油罐泄漏油蒸汽为研究对象,以数值模拟为研究方法,研究了汽油蒸汽泄漏及爆炸规律。研究发现:在距地面高1 m的平面上,当无风且呼吸阀泄漏油蒸汽速率为0.25 m/s时,距该罐中心50 m以外就可视作安全区域;当呼吸阀泄漏的油蒸汽速率为0.25 m/s时,风速达到5.0 m/s及以上,不易积聚成爆炸油蒸汽;当无风时,呼吸阀泄漏油蒸汽的速率增大1个量级,油蒸汽积聚达到爆炸下限1/2所需时间缩短2个量级;当风速为3.0 m/s、呼吸阀泄漏油蒸汽速率为0.25 m/s、泄漏时间为200 s、着火点距罐壁1 m时,距点火源距离增大1个量级,超压峰值下降1～2个量级。
When the oil depot is in fire,a large amount of gasoline vapor is formed by the heat absorption of oil in an adjacent gasoline tank with a fixed top. The gasoline vapor is ignited after mixing with air, which is likely to cause combustion and explosion accidents. In this paper, the gasoline vapor leaked from a tank of 5 000 m~3(? 22 m×13 m) is taken as the research object, the law of gas vapor leakage and explosion is researched by numerical simulation. It is found that the area beyond 50 m away from the tank center is safe at 1 m above the ground if there is no wind and the gasoline vapor leakage velocity is 0.25 m/s. It is not easy to accumulate into the flammable gasoline vapor as the gasoline vapor leakage velocity from the breathing valve is 0.25 m/s, and the wind speed reaches 5.0 m/s and above. As there is no wind and the gasoline vapor leakage velocity from the breathing valve is increased by 1 order of magnitude, the time to half of the lower flammability limit is reduced by 2 orders of magnitude. When the wind speed is 3.0 m/s, the gasoline vapor leaking velocity is 0.25 m/s, and the leakage time is 200 s, the peak overpressure is reduced by 1-2 orders of magnitude if the distance to the ignition source is increased by 1 order of magnitude.
When the oil depot is in fire,a large amount of gasoline vapor is formed by the heat absorption of oil in an adjacent gasoline tank with a fixed top. The gasoline vapor is ignited after mixing with air, which is likely to cause combustion and explosion accidents. In this paper, the gasoline vapor leaked from a tank of 5 000 m~3(? 22 m×13 m) is taken as the research object, the law of gas vapor leakage and explosion is researched by numerical simulation. It is found that the area beyond 50 m away from the tank center is safe at 1 m above the ground if there is no wind and the gasoline vapor leakage velocity is 0.25 m/s. It is not easy to accumulate into the flammable gasoline vapor as the gasoline vapor leakage velocity from the breathing valve is 0.25 m/s, and the wind speed reaches 5.0 m/s and above. As there is no wind and the gasoline vapor leakage velocity from the breathing valve is increased by 1 order of magnitude, the time to half of the lower flammability limit is reduced by 2 orders of magnitude. When the wind speed is 3.0 m/s, the gasoline vapor leaking velocity is 0.25 m/s, and the leakage time is 200 s, the peak overpressure is reduced by 1-2 orders of magnitude if the distance to the ignition source is increased by 1 order of magnitude.
引文
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[4]任少云.爆炸下限临界浓度丙烷-空气混合过程及可燃性研究[J].高压物理学报,2017,31(5):629-636.DOI:10.11858/gywlxb.2017.05.017.REN Shaoyun.The mixing and explosion process of propane-air at lower flammable limit in confined vessel[J].Chinese Journal of High Pressure Physics,2017,31(5):629-636.DOI:10.11858/gywlxb.2017.05.017.
[5]LI Guoqing,DU Yang,WANG Shimao,et al.Large eddy simulation and experimental study on vented gasoline-air mixture explosions in a semi-confined obstructed pipe[J].Journal of Hazardous Materials,2017,339:131-142.DOI:10.1016/j.jhazmat.2017.06.018.
[6]DU Yang,ZHANG Peili,ZHOU Yi,et al.Suppressions of gasoline-air mixture explosion by non-premixed nitrogen in a closed tunnel[J].Journal of Loss Prevention in the Process Industries,2014,31:113-120.DOI:10.1016/j.jlp.2014.07.012.
[7]任海亮.火灾情况下固定顶油罐物理性爆炸研究[D].廊坊:中国人民武装警察部队学院,2014:26-36.REN Hailiang.Research on physical explosion of fixed-roof tanks under fire condition[D].Langfang:The Chinese People’s Armed Police Force Academy,2014:26-36.
[8]李建华.灭火战术[M].北京:群众出版社,2004:323-325.
[9]Fluent Inc.Fluent 6.3 user’s guide[M/CD].Fluent Inc.,2006:1628-1641.
[10]王福军.计算流体动力学分析CFD软件原理与应用[M].北京:清华大学出版社,2004:7-13.
[11]张玉洁.油气及有毒性气体泄漏扩散危险性研究[D].西安:长安大学,2015:24-26.ZHANG Yujie.Study on the leakage and diffusion dangers of oil gas and toxic gases[D].Xi’an:Chang’an University,2015:24-26.
[12]王晓程.常低压储罐呼吸阀呼吸量计算与设置[J].天津化工,2016,30(6):56-58.WANG Xiaocheng.Breather valve calculation and setup for atmospheric and low-pressure storage tanks[J].Tianjin Chemical Industry,2016,30(6):56-58.
[13]傅智敏,黄金印,臧娜.爆炸冲击波伤害破坏作用定量分析[J].消防科学与技术,2009,28(6):390-395.FU Zhimin,HUANG Jinyin,ZANG Na.Quantitative analysis for consequence of explosion shock wave[J].Fire Science and Technology,2009,28(6):390-395.