深度填埋条件下堆体表面电势分布特征及漏洞定位机理

发布时间：2018-11-24 16:50

【摘要】：为研究运行期填埋场深度填埋条件下偶极子渗漏检测和漏洞定位的可行性,通过系统分析运行期填埋场的结构特征和漏洞特征,建立了偶极子检测的概念模型、控制方程和定解条件;基于Comsol Multiphysics高仿真数值模拟软件对上述问题进行有限元求解,并根据现场实测数据对模拟结果进行验证,最后利用该模型讨论了运行期填埋场偶极子漏洞检测和定位的可行性及影响因素.结果表明:数值模型模拟的特征点(极大值点和极小值点)与实际测量点位的y坐标(电势差分值)相对误差最大为24.95%,x坐标(距离)相对误差最大为3.40%,表明模型及其求解方法合理,可用于模拟实际的偶极子检测.在深度填埋(堆体厚度最大15 m)条件下,堆体表面电势差分信号降至m V级别,超出传统铜电极+万用表的检出限.受填埋深度影响,堆体表面电势分布特征与库底电势分布特征差异较大,电势峰值点位置相差达8.0 m,偶极子装置虽可检测出库底漏洞的存在,但是不能准确对其定位(x方向偏移2.0 m,y方向偏移8.0 m).此外,堆体表面的地形起伏会形成伪漏洞信号,干扰漏洞识别;沿测线方向平行移动电极,测线上的漏洞信号也会同时移动,并且关于实际漏洞位置对称.研究显示,在运行期填埋场条件下,传统偶极子漏洞定位方法(即直接根据测线上的异常信号进行漏洞定位)不再适用,但可以通过平行移动地表电极位置,观察地表电极移动过程中疑似漏洞信号的对称中心来进行漏洞定位.
[Abstract]:In order to study the feasibility of dipole leakage detection and leak location under the condition of deep landfill, a conceptual model of dipole detection was established by systematically analyzing the structural and loophole characteristics of the landfill during operation. Governing equation and definite solution condition; The above problems are solved by finite element method based on Comsol Multiphysics high simulation numerical simulation software, and the simulation results are verified according to the field measured data. Finally, the feasibility and influencing factors of the detection and location of dipole holes in the landfill during the operation period are discussed by using the model. The results show that the maximum relative error between the characteristic point (maximum point and minimum point) and the y coordinate (potential difference fraction) of the actual measured point is 24.95x coordinate (distance), and the maximum relative error is 3.40th. It shows that the model and its solution method are reasonable and can be used to simulate the actual dipole detection. Under the condition of deep landfill (the maximum thickness of the reactor is 15 m), the potential difference signal on the surface of the reactor is reduced to MV level, which exceeds the detection limit of the traditional copper electrode multimeter. Under the influence of the landfill depth, the potential distribution on the surface of the reactor is different from that on the bottom of the reservoir, and the peak position of the potential is 8.0 m. Although the dipole device can detect the existence of the hole in the bottom of the reservoir, However, it is not possible to accurately position the location (x shift 2.0 MJ shift 8.0 m). In addition, the topographic fluctuation on the surface of the heap will result in false leak signals, which will interfere with the identification of the holes, and parallel moving electrodes along the direction of the measuring lines, the leak signals on the test lines will also move at the same time, and the location of the actual vulnerabilities will be symmetrical. The research shows that the traditional dipole vulnerability location method (that is, locating vulnerabilities directly based on abnormal signals on the line) is no longer applicable under the condition of the running landfill, but it can be used to move the surface electrode position in parallel. Observe the symmetry center of the suspected leak signal during the surface electrode movement to locate the vulnerability.
【作者单位】：中国环境科学研究院固体废物污染控制技术研究所;北京师范大学水科学学院;
【基金】：国家科技支撑计划项目(2014BAL02B00) 国家环境保护公益性行业科研专项重点项目(201209022) 国家自然科学基金项目(61503219)
【分类号】：X705

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