LPG埋地储罐泄漏和渗流扩散影响因素分析

研究液化石油气（LPG）埋地储罐泄漏、LPG渗流扩散的影响因素对其事故的预防、预测、应急等具有重要意义。为此， 分析了导致LPG埋地储罐泄漏的影响因素，重点对LPG在渗流扩散过程中的影响因素进行分析，利用CFD（Computational Fluid Dynamics）模型对LPG在各种地下环境中的渗流扩散过程进行数值模拟，讨论渗透率、孔隙度、水饱和度、重力、扩散到外界环境的出口位置等因素对LPG渗流扩散的影响，得到如下结论：LPG在多孔介质渗流过程中分子扩散作用对LPG渗流扩散的影响很小；重力、出口位置对LPG渗漏扩散方向影响很大，使流体倾向于重力、出口方向移动；含水量较小、孔隙度和渗透率较大的多孔介质，流体渗流速度下降梯度相对较小，渗流扩散快；黏滞力对渗流速度的影响不可忽视。在此基础上，提出泄漏事故发生后应急救援的措施。

INFLUENCING FACTORS OF LEAKAGE AND INFILTRATION DIFFUSION FOR LPG UNDERGROUND STORAGE TANK

Analyses on the influencing factors of the LPG underground storage tank leakage and LPG infiltration diffusion are of great importance to the prevention, prediction, and emergency of underground storage tank accidents. This paper firstly introduced those influencing factors leading to the leakage of LPG underground storage tank. By use of CFD (Computational Fluid Dynamics) model to simulate a migration of LPG under various underground environments, this study then focused its study on how LPG infiltration diffusion was caused by many factors such as permeability, porosity, water saturation, gravity, outlet position in tank pond. After discussion some results were obtained as follows: ①the molecular diffusion effect has little influence on the LPG diffuse seepage in the porous medium; ②the LPG infiltration direction was significantly affected by gravity and the position of outlet and the fluid was tend to migrate in the direction of gravity and outlet; ③ the descending gradient of infiltration velocity was relatively smaller in porous media with lower water saturation, higher porosity, and higher permeability; ④the influence of viscous force can not be negligible. Based on these results of study, this paper put forward some emergency measures against the leakage accidents to slow down the speed and reduce the LPG leakage rate and so to extend the time which it took to diffuse outside.