Civil and Environmental Engineering Department, California Polytechnic State University, 1 Grand Ave., San Luis Obispo, CA 93407, USA.
Waste Manag. 2013 Oct;33(10):1993-2000. doi: 10.1016/j.wasman.2013.04.003. Epub 2013 May 10.
A numerical modeling approach has been developed for predicting temperatures in municipal solid waste landfills. Model formulation and details of boundary conditions are described. Model performance was evaluated using field data from a landfill in Michigan, USA. The numerical approach was based on finite element analysis incorporating transient conductive heat transfer. Heat generation functions representing decomposition of wastes were empirically developed and incorporated to the formulation. Thermal properties of materials were determined using experimental testing, field observations, and data reported in literature. The boundary conditions consisted of seasonal temperature cycles at the ground surface and constant temperatures at the far-field boundary. Heat generation functions were developed sequentially using varying degrees of conceptual complexity in modeling. First a step-function was developed to represent initial (aerobic) and residual (anaerobic) conditions. Second, an exponential growth-decay function was established. Third, the function was scaled for temperature dependency. Finally, an energy-expended function was developed to simulate heat generation with waste age as a function of temperature. Results are presented and compared to field data for the temperature-dependent growth-decay functions. The formulations developed can be used for prediction of temperatures within various components of landfill systems (liner, waste mass, cover, and surrounding subgrade), determination of frost depths, and determination of heat gain due to decomposition of wastes.
已开发出一种数值建模方法来预测城市固体废物填埋场中的温度。描述了模型公式和边界条件的详细信息。使用来自美国密歇根州的垃圾填埋场的现场数据评估了模型性能。数值方法基于有限元分析，结合瞬态传导传热。代表废物分解的发热函数是通过经验开发并纳入公式的。使用实验测试、现场观测和文献中报告的数据确定材料的热物理性质。边界条件包括地面季节性温度循环和远场边界恒定温度。通过建模的概念复杂程度的不同，逐步开发了发热函数。首先，开发了一个阶跃函数来表示初始（好氧）和残余（厌氧）条件。其次，建立了指数增长-衰减函数。第三，该函数按温度依赖性进行了缩放。最后，开发了一个能量消耗函数来模拟随温度变化的废物年龄的发热情况。结果与温度相关的生长-衰减函数的现场数据进行了比较。所开发的配方可用于预测填埋场系统各组成部分（衬垫、废物质量、覆盖层和周围底基层）内的温度、确定冻结深度以及确定废物分解产生的热量增益。
