某大型LNG储罐泄漏扩散及其影响因素研究
Research on Leakage and Diffusion of a Large LNG Storage Tank and Its Influencing Factors
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- 引用格式:
-
杨兆晶,侯磊,朱淼.某大型LNG储罐泄漏扩散及其影响因素研究[J].天然气与石油,2020,38(1):47-53.doi:10.3969/j.issn.1006-5539.2020.01.008
Yang Zhaojing, Hou Lei, Zhu Miao.Research on Leakage and Diffusion of a Large LNG Storage Tank and Its Influencing Factors[J].Natural Gas and Oil,2020,38(1):47-53.doi:10.3969/j.issn.1006-5539.2020.01.008
- DOI:
- 10.3969/j.issn.1006-5539.2020.01.008
- 作者:
- 杨兆晶 侯磊 朱淼
Yang Zhaojing, Hou Lei, Zhu Miao
- 作者单位:
- 中国石油大学(北京)机械与储运工程学院
College of Mechanical and Transportation Engineering, China University of Petroleum (Beijing), Beijing, 102249, China
- 关键词:
- LNG储罐;泄漏扩散;数值模拟;风速;风向;障碍物;罐区
LNG storage tank; Leakage and diffusion; Numerical simulation; Wind speed; Wind direction; Obstacles; Tank farm
- 摘要:
大型LNG储罐内储存着大量低温且易燃易爆的LNG,一旦发生泄漏将对周边人群、财产及大气环境造成极大危害。针对南方某LNG接收站的大型LNG储罐建立三维数值模型,对LNG泄漏扩散过程进行数值模拟,分析风速、风向与障碍物对LNG泄漏扩散的影响规律。结果表明:风对高浓度气云的混合稀释作用较强,对低浓度气云的平流输送作用较强且大风速更利于促进气云扩散,3 m/s的低风速下1/2爆炸下限气云下风向最远距离可达554 m;从顺风泄漏到逆风泄漏,储罐本身对气云扩散的阻碍作用逐渐增强,气云扩散速度逐步减慢,逆风泄漏最不利于气云扩散,稳定后形成的危险区域最大;障碍物会导致重气云短期聚积,并使得气云扩散时呈现攀爬和分流两种形式;将相同环境条件下的单罐及罐区泄漏扩散后果进行对比,发现同一时刻的罐区危险气云体积比单罐危险气云体积大得多,主要是由于罐区其他大型储罐在改变风场分布的同时阻碍气云扩散,延长了高浓度气云的停滞时间。该研究对今后预测大型LNG储罐泄漏扩散有一定借鉴意义,可为应急防护策略的制定提供参考依据。
Large LNG storage tanks contain a large amount of low-temperature and inflammable and explosive LNG, which will cause great harm to surrounding people, property and atmospheric environment once leakage occurs.A three-dimensional numerical model was established for a large LNG storage tank at the LNG receiving station in the south,and the leakage and diffusion process of LNG was simulated.Then the influence of wind speed, wind direction and obstacles on the leakage and diffusion of LNG was analyzed.The results show that the wind has a stronger effect on mixed dilution of high concentration gas cloud,and a stronger effect on advection transport of low concentration gas cloud.Under low wind speed of 3m/s, the farthest downwind direction of gas cloud with 1/2 lower explosive limit can reach 554m.From downwind leakage to upwind leakage, the obstruction effect of the storage tank on gas cloud diffusion gradually increases,and the diffusion speed of gas cloud gradually slows down.The upwind leakage is the most unfavorable to the diffusion of gas cloud,and the most dangerous area is formed after stabilization.Obstacles will lead to the short-term accumulation of heavy gas cloud,and make the diffusion of gas cloud present two forms: climbing and diverging.By comparing the leakage and diffusion consequences of single tank and tank farm under the same environmental conditions,it is found that the volume of dangerous gas cloud in the tank farm at the same time is much larger than that of single tank.The main reason is that other large storage tanks in the tank farm hinder the gas cloud diffusion while changing the distribution of wind field,and extend the stagnation time of high concentration gas cloud.The research will provide reference for the prediction of the consequences of leakage and diffusion of large LNG tanks in the future, and serve as a basis for the formulation of emergency protection strategies.
