摘要
在石油开采、加工、储存和运输过程中泄漏或渗漏频频发生,对生态环境造成严重损害,研究汽煤柴油油气在细砂中的扩散规律对及时处置和评估污染事件具有一定的现实意义。通过对一维条件下Fick第二定律的求解,得到扩散系数的求解方程。由试验和曲线拟合得到汽煤柴油油气在细砂中的扩散系数。采用MATLAB PDE工具箱对汽煤柴油油气的二维扩散方程进行了数值求解。说明了数值计算结果与实际试验结果存在差异的原因,即逐渐增大油浸体的重要影响,指出下一步研究要考虑含水量对扩散的影响。最后分析了汽煤柴油油气在细砂中的扩散规律,结果表明:1)随着时间的推移,挥发物会向四周非均匀地扩散,在以挥发源为圆心的圆周上油气体积比相等;2)经过相同时间的扩散后,汽油油气的扩散半径最大,航煤次之,柴油最小,这与3种油气在砂层中的有效扩散系数逐渐递减密切相关;3)3种油气扩散半径与时间的关系均可以用乘幂函数来表示,并且曲线拟合的相关程度都很高。
This paper is aimed at introducing our research findings on the diffusion regularity of gasoline, kerosene and diesel oil vapor in the fine sandy particles. As is known, with the fast development of our society and the quick improvement of people＇ s living standard, we have become more and more dependent on the fossil oilthe petroleum. In such a situation, we have to resort to Fick＇ s second law in the onedimensional conditions to solve the diffusion coeffi cient. However, since the leakage or seepage frequently occurs in the drilling, refining, processing, storage and transportation of the petroleum, such leakage accidents with its products tend to cause se rious damage to the ecological environment. The problem tends also to be of great practical significance in assessing and timely treating pollution incidents in case of the great need to study the diffusion laws of gasoline, kerosene and diesel vapor in. fine sands. In the light of the research need, we have solved the Fick＇s second law in the one dimensional condition and obtained an equation by which we can solve the diffusion coefficient. It is starting from the above said great needs, this paper is dedicated to numerical solution of the twodimen sional diffusion equations of gasoline, kerosene and diesel vapor by using the finite element method via MATLAB PDE toolbox. Though the numerical calculation results may be different from the actual test ing result, the results may still account for the great influence of the gradual increase of the oil invasion objects, it is still necessary to consider further the effects of the water content on the diffusion. And, finally, based on the analysis of the diffusion regularity of the fine sand particles about the gasoline, kerosene and the diesel oil va por, the following three conclusions can be made： （1） With the passing of time, the volatiles tend to spread to the surrounding space nonuniformly, with the oil vapor volume fraction on the circumfer ences being equal and the centre of the circumferences
出处
《安全与环境学报》
CAS
CSCD
北大核心
2014年第4期213-216,共4页
Journal of Safety and Environment
基金
军队后勤重点科研项目(油20080208)
关键词
环境工程学
细砂
汽煤柴油油气
扩散系数
扩散方程
PDE工具箱
environmental engineering
fine sand
gasoline, kerosene and diesel oil vapor
diffusion coefficient
diffusion equation
partial differential equation toolbox
