竖井SVE修复有机污染土壤的数值模拟分析  

NUMERICAL ANALYSIS OF REMEDIATION OF ORGANIC CHEMICALS-CONTAMINATED SOIL BY VERTICAL WELL SVE

作　　者：黄国强[1] 李鑫钢[1] 姜斌[1] 李凌[1] 徐世民[2] 干爱华[2] 

机构地区：[1]天津大学化工学院,天津300072 [2]精馏技术国家工程研究中心,天津300072

出　　处：《化工学报》2003年第8期1134-1140,共7页CIESC Journal

基　　金：国家自然科学基金资助项目 (No 2 0 2 760 48)~~

摘　　要：采用Galerkin三角形有限单元法对复合地表边界的竖井土壤气相抽提 (SVE)稳态流动问题进行了数值模拟分析 ,模拟结果显示 :气相压力沿径向梯度迅速下降 ,抽提流量与土壤通透系数及真空度呈现高度相关的正比例关系 ,且地表隔绝覆盖层对流场影响很大 .通过与野外实测真空度数据的对比验证 ,表明该二维轴径向流动模型能较好应用于现场条件 ,明显优于一维模型 .再采用一个稳定的交替方向有限差分 (ADI)解出传质微分方程 ,从而实现多维情况下竖井SVE修复的完整模拟过程 . 4组不同条件下为期 6 0d的SVE修复过程的计算机模拟显示 ,土壤通透系数是决定修复效果的关键因素 .Numerical simulations with the Galerkin's finite element method are made to study steady state flow under different simulation conditions at a vertical well site of soil vapor extraction (SVE) Flow field simulation shows that radial pressure gradient goes down fast and air flowrate is nearly directly proportional to the well vacuum and the soil permeability coefficient It also indicates that stop off coating will play an important role in SVE This axisymmetric 2D flow model can predict vacuum distribution, which gives a much better fit to field data by contrast to 1D model The numerical modeling process for SVE remediation is achieved after a steady alternant direction implicit (ADI) finite difference format is developed In this paper, as an example, the 60 days remediation under 4 different conditions is simulated, which proves that the clear up result is mainly governed by soil permeability This work will be used as a tool for engineering design and prediction for SVE remediation

关 键 词：土壤气相抽提 对流扩散方程 土壤修复 数值模拟 流场分析 传质分析 

分 类 号：TQ028.1[化学工程] X131[环境科学与工程—环境科学]