海底输气管道泄漏扩散模拟及正交试验分析

摘要

In order to study the law of leakage and diffusion of submarine gas pipeline,and to provide reference for the leakage accident consequences prediction.The orthogonal experiment was used to analyze the three main factors of the leaking rate,the velocity of ocean current and the size of leaking hole which affect the diffusion law of submarine pipeline natural gas leakage,select L9(34) orthogonal array to design the test scheme,using the Computational Fluid Dynamics (CFD) software to simulate the leakage and diffusion of natural gas in seawater,the significance of the factors affecting the gas diffusion range and the time to reach the sea surface was determined through comprehensive comparison and variance analysis.The results show that the form of air mass,the mixing degree of gas and sea water,the time of gas to arrive the sea surface and the gas influence range are all affected by the above factors.The leaking rate and the size of leaking hole are the significant factors that affect the time of leaking gas to reach the sea surface.The influence of ocean current velocity and the size of leaking hole affect the leaking gas diffusion range,but both are non-significant factors.Comprehensive investigate the experiment indexes of the leakage diffusion,the size of leaking hole and the velocity of ocean current are the significant factors,and the leaking rate is the non-significant factor.%为研究海底输气管道泄漏扩散的规律,对泄漏事故后果预测提供参考,采用正交试验法对影响海底泄漏天然气扩散规律的气体泄漏速度、洋流速度和泄漏孔径尺寸3个主要因素进行分析.选取L9(34)正交表设计试验方案,利用计算流体力学(CFD)软件对泄漏天然气在海水中的扩散进行模拟试验,使用综合比较法与方差分析法确定了影响气体扩散范围和到达海面时间的影响因素的主次关系与显著情况.结果表明,上述因素对气团形态、气体与海水混合程度,气体到达海面时间及扩散范围等均有影响.泄漏速度与泄漏孔径尺寸为影响泄漏气体到达海面时间的显著因素;洋流速度与泄漏孔径尺寸影响泄漏气体扩散范围,但二者都为非显著因素.综合考察泄漏扩散的试验指标,泄漏孔径尺寸与洋流速度为影响结果的显著因素,泄漏速度为非显著因素.