分层填埋场竖井及水平井联合抽气

Gas Migration in Layered Landfills Incorporating Vertical and Horizontal Extraction Wells

采用特征函数展开法求解分层填埋场的二维气体运移模型,考虑了由于压缩、降解和含水量分布不均等引起的产气率和渗透系数成层特性以及垃圾的各向异性,然后结合边界和连续性条件确定其待定参数.最后,基于考虑了气体竖向和水平向运移的解析解,研究了竖井、水平井收集系统和排气层对填埋场内气体压力和回收率的影响,进一步提出了土工膜覆盖下填埋场气体收集系统的设计方法.

A new two dimensional gas flow model was developed to analyze the gas migration in layered landfills. The model considers anisotropy of the municipal solid wastes （MSWs）, and vertical variations in both gas generation and permeability caused by compression, degradation and inhomogeneous distribution of moisture content. The general solution of this model can be developed using eigenfunction expansion method, and the unknown integration constants can be determined by the boundary and continuity conditions. According to this analytical solution, the influences of vertical wells, horizontal lines and permeable layers on the gas pressure and recovery were further investigated. Finally, the design method of the landfill gas （LFG） collection system for layered landfills covered by geomembrane was proposed.