Research on leakage and diffusion of buried gas pipeline through small holes

doi:10.16265/j.cnki.issn1003-3033.2023.10.0145

Abstract

Abstract:

This study aims to reduce explosion accidents by exploring the law of gas diffusion in soil after pipeline leakage based on leakage diffusion model and experimental study. In this study, the leakage of small holes in buried gas pipeline was simulated by establishing a full-scale experimental system on gas pipeline, and gas samples in soil were collected. The law of concentration change was analyzed, such as how methane volume fraction change with time, what is the relationship between the gas concentration and the distance from the leakage points, and how soil coefficients and pressure fluctuations in pipelines influence methane volume fraction. Those data were compared with leakage diffusion model to explore the differences between the model values and experimental values, and then suggestions were proposed for revising leakage diffusion model. The results show that, firstly, the change of methane volume fraction in soil shows three trends with time: increasing steeply and getting stable, S-shape and linear. Secondly, the methane volume fraction has an exponential relationship with the distance of the leakage point after a certain amount of leakage time. Thirdly, diffusion of gas in soil is affected by the physical parameters of soil. Fourthly, the saturation time of methane volume fraction in soil is 1/10 of the model value. Under low pressure, the saturation concentration of gas in close range soil is twice that of model value, while under high pressure, the saturation concentration of gas in distant soil is 5 times that of model value.

Key words: buried gas pipeline, soil, leakage of small holes, diffusion, methane volume fraction

DENG Bingbing, XIE Yushu, DENG Fang, GE Yue, LYU Lianghai, ZHANG Xiaofeng. Research on leakage and diffusion of buried gas pipeline through small holes[J]. China Safety Science Journal, 2023, 33(10): 160-166.

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References 18

[1]	谢昱姝, 吴宗之, 吕良海, 等. 城市管道天然气在土壤中泄漏扩散实验研究[J]. 中国安全生产科学技术, 2012, 8(4):13-17.
	XIE Yushu, WU Zongzhi, LYU Lianghai, et al. Experimental research on diffusion behavior of leaked gas from underground gas pipeline[J]. Journal of Safety Science and Technology, 2012, 8(4):13-17.
[2]	熊兆洪, 李振林, 宫敬, 等. 埋地管道小泄漏模型及数值求解[J]. 石油学报, 2012, 33(3):493-498. doi: 10.7623/syxb201203023
	XIONG Zhaohong, LI Zhenlin, GONG Jing, et al. A model for underground pipeline small leakage and its numerical solution[J]. Acta Petrolei Sinica, 2012, 33(3):493-498. doi: 10.7623/syxb201203023
[3]	张鹏, 程淑娟. 埋地天然气管道小微孔泄漏规律研究[J]. 中国安全科学学报, 2014, 24(2):52-58.
	ZHANG Peng, CHENG Shujuan. Study on small microspore leakage in buried gas pipeline[J]. China Safety Science Journal, 2014, 24(2):52-58.
[4]	SHANTANU J, AMIT P, ARGHYA D, et al. Analysis of buried pipelines subjected to reverse fault motion[J]. Soil Dynamics & Earthquake Engineering, 2011, 31(7):930-940.
[5]	KIM K, ZHOU Wei, HUANG S L. Frost heave predictions of buried chilled gas pipelines with the effect of permafrost[J]. Cold Regions Science & Technology, 2008, 53(3):382-396.
[6]	王志荣, 蒋军成, 潘旭海. 模拟评价方法在劳动安全卫生预评价中的应用研究[J]. 石油与天然气化工, 2003, 32(3):181-184.
	WANG Zhirong, JIANG Juncheng, PAN Xuhai. Research on the application of simulation assessment in health and safety evaluation[J]. Chemical Engineering of Oil & Gas, 2003, 32(3):181-184.
[7]	HANNA S. Britter and McQuaid (B&M) 1988 workbook nomograms for dense gas modeling applied to the Jack Rabbit II chlorine release trials[J]. Atmospheric Environment, 2020:DOI:10.1016/j.atmosenv.2020.117539.
[8]	LIU Yanping, ZHAO Yongqiang, LIU Ming, et al. Parameterized high-precision finite element modelling method of 3D helical gears with contact zone refinement[J]. Shock and Vibration, 2019, 2019:1-17.
[9]	王向阳, 杜美萍, 汪彤, 等. 埋地燃气管道泄漏扩散过程数值模拟[J]. 中国安全科学学报, 2018, 28(2):45-50.
	WANG Xiangyang, DU Meiping, WANG Tong, et al. Numerical simulation of leakage of gas from buried pipeline and its diffusion process[J]. China Safety Science Journal, 2018, 28(2):45-50.
[10]	林晓斌. 埋地天然气管道泄漏过程天然气在土壤中扩散的数值模拟研究[D]. 北京: 北京化工大学, 2014.
	LIN Xiaobin. Numerical study on diffusion of the natural gas leakage from buried gas pipeline[D]. Beijing: Beijing University of Chemical Technology, 2014.
[11]	李云涛, 张振永, 刘玉卿, 等. 天然气管道全管径断裂事故影响范围研究[J]. 中国安全科学学报, 2020, 30(9):149-154.
	LI Yuntao, ZHANG Zhenyong, LIU Yuqing, et al. Influence range of full bore rupture accidents of natural gas pipelines[J]. China Safety Science Journal, 2020, 30(9):149-154.
[12]	李朝阳, 马贵阳. 埋地与架空输气管道泄漏数值模拟对比分析[J]. 天然气工业, 2011, 31(7):90-93,113.
	LI Chaoyang, MA Guiyang. A comparative study of numerical simulation on underground and aerial pipeline leakage at instantaneous and continuous states[J]. Natural Gas Industry, 2011, 31(7):90-93,113.
[13]	王秋红, 王力文, 蒋军成, 等. 城镇地埋天然气管道泄漏诱发气云爆炸仿真[J]. 中国安全科学学报, 2021, 31(9):75-82. doi: 10.16265/j.cnki.issn1003-3033.2021.09.011
	WANG Qiuhong, WANG Liwen, JIANG Juncheng, et al. Simulation study on gas explosion induced by gas leakage of urban buried gas pipeline[J]. China Safety Science Journal, 2021, 31(9):75-82. doi: 10.16265/j.cnki.issn1003-3033.2021.09.011
[14]	冯文兴, 王兆芹, 程五一. 高压输气管道小孔与大孔泄漏模型的比较分析[J]. 安全与环境工程, 2009, 16(4):108-110.
	FENG Wenxing, WANG Zhaoqin, CHENG Wuyi. Analysis of the nozzle model and hole model associated with high-pressure natural gas pipeline leakage[J]. Safety and Environmental Engineering, 2009, 16(4):108-110.
[15]	冯云飞, 吴明, 闫明龙, 等. 燃气管道泄漏模型的研究进展[J]. 当代化工, 2011, 40(12):1255-1257,1260.
	FENG Yunfei, WU Ming, YAN Minglong, et al. Research progress in leakage models for gas pipelines[J]. Contemporary Chemical Industry, 2011, 40(12):1255-1257,1260.
[16]	庞磊, 吕良海, 刘晨, 等. 密闭空间燃气泄漏爆炸危险区域迁移规律[J]. 中国安全生产科学技术, 2012, 8(8):47-50.
	PANG Lei, LYU Lianghai, LIU Chen, et al. Migration laws of hazardous zone for natural gas leakage explosion in enclosed spaces[J]. Journal of Safety Science and Technology, 2012, 8(8):47-50.
[17]	GB 50028—2006, 城镇燃气设计规范[S].
	GB 50028-2006, Cole for design of city gas engineering[S].
[18]	谢昱姝, 汪彤, 吕良海, 等. 城市管道天然气在土壤中扩散行为全尺度实验[J]. 天然气工业, 2015, 35(8):106-113.
	XIE Yushu, WANG Tong, LYU Lianghai, et al. Full-scale experiment of diffusion behaviors of city pipeline gas in soils[J]. Natural Gas Industry, 2015, 35(8):106-113.

试验编号	管道压力/MPa	管径/mm	泄漏口直径/mm
工况1	2.5×10^-3	20	4
工况2	20×10^-3	160	6
工况3	20×10^-3	160	6
工况4	0.1	160	6

状态	岩土类型	天然含水率w/%	饱和度 h	孔隙比 e	颗粒组成占比(粒径/mm)
状态	岩土类型	天然含水率w/%	饱和度 h	孔隙比 e	[0.5,2)	[0.25, 0.5)	[0.075, 0.25)	[0.05, 0.075)	[0.01, 0.05)	[0.005, 0.01)	[0.002, 0.005)
1	黏质粉土	25.1	0.85	0.80	1.3	0.4	7.3	42.2	27.8	10.2	10.8
2	黏质粉土	16.2	0.55	0.80	1.0	1.0	6.3	45.6	29.5	9.2	7.4

工况	渗透系数k	平均粒径 d/mm	孔隙度e	测点2₂₁、2₃₁ 距泄漏口距离/m	测点4₂₁、4₃₁ 距泄漏口距离/m
2	0.054	0.065	0.8	2	4
3	0.01	0.072	0.99	2	4