地埋管地源热泵系统二维和三维管群换热模型的对比分析

Comparative analyses on 2D and 3D buried tube-group heat transfer models in GCHP system

以实际工程为研究对象,分别建立垂直U型地埋管管群的二维和三维非稳态传热模型.以Fluent作为计算工具,进行系统运行15年的换热耦合计算,得到不同换热条件下的土壤温度变化曲线.以三维模型数值计算结果为对比条件,以拟合优度为参照参数,对二维传热模型的应用条件进行了分析.

Choice of a heat transfer model for buried tube-group heat exchangers （GHEs） is the key to accurate calculation of the heat exchange of GHEs in ground-coupled heat pump （GCHP） system. Based on practical projects, the 2D and 3D unsteady heat transfer models of vertical U-tube GHEs are constructed. With Fluent as a computational tool, the heat coupled calculations for a period of 15 years are carried out and soil temperature variation curves are obtained. By taking the 3D model numerical results as benchmark and goodness-of-fit as reference parameter, application conditions for the 2D model are analyzed.