垃圾土导热特性试验研究  

Experimental study on thermal conductivity of municipal solid waste

作　　者：钱正亚 施建勇[1] Qian Zhengya Shi Jianyong(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering ,Hohai University ^Nanjing 210098 , China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098

出　　处：《能源与环保》2017年第5期111-115,共5页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家自然科学基金(41510637)

摘　　要：温度会影响垃圾降解、气体运移、填埋场衬垫系统的工程特性,导热系数是研究温度场的重要参数。采用瞬态平面热源法,研究了不同孔隙比、有机质含量、含水率引起的垃圾土导热系数变化规律。研究结果表明:干垃圾的导热系数较小,随孔隙的增大而减小。饱和状态下的垃圾土导热系数为干燥状态的4~6倍,干垃圾和饱和垃圾的导热系数与垃圾土成分中的无机物体积分数呈正相关。垃圾导热特性随含水率变化呈3段特征,两个转折点与残余含水量、气体渗透特性分界点的含水量接近。水先进入颗粒间孔隙,逐渐形成连续液桥,导热系数增大较明显;垃圾土的含水量较大时,水开始填充集合体的孔隙,将大的颗粒集合体连接起来,此时导热系数将继续增大,变化率趋于平缓。Temperature can affect the waste degradation, the gas migration process and the engineering characteristics of the liner sys-tem. The thermal conductivity is an important parameter to calculate the temperature distribution. The effects of void ratio, organic con-tent, water content were analyzed by the transient plane heat source method. Test results show that,the thermal conductivity coefficient of the dry MSW is generally small and it decreases with the increase of void ratio. The thermal conductivity coefficient of saturated speci-men is about 4-6 times of that of dry state,both of them are positively correlated with the volume fraction of the inorganic. Thermal conductivity coefficients of MSW can be divided into three sections by the change of the water content. Two turning points are close to the residual water content and characteristic moisture content of gas permeability coefficient curve. The water in the MSW occupies some intergranular pores at first,gradually forms a continuous liquid bridge,the thermal conductivity increases rapidly at this stage. The water begins to fill the aggregate pores when the water content reaches a high level. As a result,the large aggregate particles become continu-ous. The thermal conductivity will continue to increase at this stage,but the rate of change reach at a stability state.

关 键 词：垃圾土 导热系数 饱和度 孔隙比 土水特征曲线 

分 类 号：TK521.2[动力工程及工程热物理—热能工程]