最不利管道泄漏情形下燃气管廊的安全性评估  

Safety assessment of gas pipe gallery in most unfavorable leakage condition

作　　者：周乐 周廷鹤 张卫军 ZHOU Le;ZHOU Tinghe;ZHANG Weijun(School of Metallurgy,Northeastern University//State Environmental Protection Key Laboratory of Eco-Industry;Nanjing Gas Engineering Design Institute Co.Ltd.)

机构地区：[1]东北大学冶金学院·国家环境保护生态工业重点实验室,辽宁省沈阳市110819 [2]南京市燃气工程设计院有限公司

出　　处：《油气储运》2021年第2期200-207,共8页Oil & Gas Storage and Transportation

基　　金：国家重点研发计划项目“工业园区多能流综合管控与协同优化”,2017YFA0700300。

摘　　要：地下燃气管廊属于半密闭空间,燃气管道一旦发生泄漏极易引发严重的爆炸事故,对泄漏发生后管廊的安全性进行分析可以为事故的应急处理提供理论指导。为此,根据中国某燃气管廊的结构,针对燃气管道最不利点处发生泄漏的情形,采用CFD软件对其进行建模及求解,研究不同泄漏孔径及不同通风模式下管廊内甲烷质量浓度的变化情况,划分管廊内的爆炸危险区域,并对管廊的安全性作出评估。研究结果表明:当泄漏孔径分别为10 mm、50 mm、100 mm时,管廊内甲烷的质量浓度场趋于稳定后,事故通风模式下管廊顶部的甲烷质量浓度较正常通风模式分别下降了50%、45%、36%;当通风量一定时,泄漏孔径的增大虽然会带来燃气泄漏量的增加,但并非一定会导致危险区域的扩大,较小的泄漏孔径可能会带来更大的安全隐患;当燃气泄漏量较大时,如不能控制好通入的空气量与泄漏的燃气量之间的比例关系,反而可能会引发更为严重的后果。妥善处理管廊内燃气管道泄漏事故的关键在于控制好通风量和甲烷泄漏量之间的比例关系。Underground gas pipe gallery is a semi-closed space. Once leakage occurs in the gallery, it is likely to induce serious explosion accidents. Safety assessment of pipe gallery after leakage can provide theoretical guidance for emergency treatment of such accidents. Therefore, according to the structure of a domestic gas pipe gallery, modeling and solution with CFD software were conducted for leakage at the most unfavorable point of the gas pipeline. The variation of mass concentration of methane in the pipe gallery under different leakage diameters and ventilation modes was studied, the explosion hazard area was divided within the pipe gallery, and the safety of pipe gallery was assessed. The results show that for the leakage diameters of 10 mm, 50 mm and 100 mm, after the mass concentration field of methane in the pipe gallery becomes stable, the mass concentration of methane at the top of the pipe gallery in the accident ventilation mode is reduced by 50%, 45% and 36% respectively, compared with that in the normal ventilation mode. In the case that the ventilation volume is constant, the enlargement of the leakage diameter will increase the leakage volume of natural gas, but it will not necessarily lead to the expansion of hazard areas, and a smaller leakage diameter may bring more potential safety hazards. When the leakage is large, more serious consequence may be resulted in if the proportion between the air volume and the leaked gas volume cannot be controlled properly. The key to deal with the gas pipeline leakage in pipe gallery is to control the proportional relationship between the ventilation volume and the methane leakage volume.

关 键 词：燃气管廊 泄漏 最不利点 数值模拟 危险区域 安全评估 

分 类 号：TE88[石油与天然气工程—油气储运工程]