热油泄漏对土壤温度场影响的模拟分析

The Simulation Analysis of Soil Temperature Field Affected by Hot Oil Leakage

借助CFD(Computational Fluid Dynamics)软件建立土壤多孔介质中流固耦合的相变数学模型,对埋地管道上部泄漏热油在冬夏季不同土壤中渗透扩散时,大地温度场的变化进行模拟分析。模拟结果表明:泄漏前,热油管道冬夏季长期运行所形成的径向稳态温度场等温线分布呈近似的对称状态;泄漏发生后,热油凝点以上的液相热影响区域冬夏季等温线分布相似,均是以扇形区域逐步向四周扩张,固液两相区外围的热影响区冬季冻土中的温度梯度大于夏季泄漏工况;热油在冬季冻土中的扩散速率比夏季低约3%。

Based on the mathematical modeling of phase transition of fluid-solid coupling in the soil porous media being built by CFD,the change of soil temperature field can be analyzed when hot oil penetrates and diffuses from the upper part of buried pipeline in different soil in summer and winter.The result shows that before leaking,the isothermal line is nearly symmetrical in the radial steady temperature field being formed by the operation of hot oil pipeline in summer and winter.After leaking,the isothermal line is spreaded in the shape of sector from the center of leaking point and the distributions of isothermal line are similar in winter and summer in liquid heat-affected zone of which the degree of temperature is above the hot oil solidifying point.Also,the temperature gradient of the heat-affected zone outside the solid and liquid phases is larger than that in the summer case.The diffusion rate of hot oil in summer is lower than the rate in winter about 3% in the frozen soil.