Abstract A mathematical model for three layer media with different thermal conductivities is presented for analyzing the three-dimensional heat conduction of the repository. The solutions to the temperature distribution in the bentonite block layer, bentonite pellet layer and surrounding rock were derived through applying the Fourier and Laplace transforms upon the heat conduction equations. These analytical solutions can be used to obtain the evolution of temperature fields at the repository site. Finally, a parametric study is carried out to assess the effects of geometry dimension and thermal conductivity on the thermal performance. The results show that the three layer model was demonstrated more accurately to simulate the temperature field in the repository through comparative analysis with the existing double layer model and line heat source model. The thickness of the bentonite pellet layer will lead to a significant increase in the peak buffer layer temperature because of its low thermal conductivity.

中文翻译：

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核废料储存库中具有三个热传导层的新热分析模型

摘要 提出了一种不同热导率的三层介质的数学模型，用于分析库的三维热传导。通过对热传导方程应用傅里叶变换和拉普拉斯变换，推导出了膨润土块层、膨润土颗粒层和围岩中温度分布的解。这些解析解可用于获得储存点温度场的演变。最后，进行参数研究以评估几何尺寸和热导率对热性能的影响。结果表明，通过与现有双层模型和线热源模型的对比分析，证明了三层模型能够更准确地模拟库内温度场。膨润土颗粒层的厚度会导致峰值缓冲层温度显着增加，因为其导热系数低。