竖直U型地埋管群传热特性模拟
Simulation of heat transfer characteristics of vertical U-shaped buried tubes

为了探究不同因素对竖直U型地埋管管群传热特性的影响，以竖直U型地埋管周围土壤为研究对象，建立三维非稳态传热物理数学模型。在试验验证和单井的研究基础上，以1 a为研究周期，分析了地埋管管群排列方式、热泵蓄取功率比以及土壤类型对竖直U型地埋管管群周围土壤温度场分布的影响。研究表明：钻井间距一定时，地埋管排列方式对地埋管管群周围土壤温度场分布的影响很小；在热泵运行时间一定时，土壤热扩散系数越大，钻井间土壤温度重叠区域越大；土壤导热系数越大，土壤温度波动幅度越小；蓄取功率比越小，土壤热失衡越严重；对于冬季热负荷较大的地区，可以适当地提高热泵蓄取功率比。所建模型得出的土壤温度值与试验值吻合度较好，其最大误差为14.2%。
In order to investigate the influence of different factors on heat transfer law around the Vertical U-Tube ground boreholes' group, three-dimensional physical and mathematical models of unsteady heat transfer were established for the soil around the vertical U-tube ground boreholes' group. The heat storage was studied on the basis of experimental verification and single U, a year was taken as the time domain, the effects of the arrangement of the underground pipe, rate of the heat storage and release and soil type on the soil temperature distribution of the Vertical U-Tube ground boreholes' group were analyzed. The results indicate that the arrangement of the underground pipes has little influence on the soil temperature around the buried pipe group when the distance of drilling is constant; The overlay area of soil temperature between drillings increases with the increase of soil thermal diffusivity when operation time is constant; The fluctuation range of soil temperature decrease with the increase of soil thermal conductivity; Heat imbalance of soil becomes serious with the decrease of the heat storage and release rate; For the region of larger heating load, it should appropriately improve rate of the heat storage and release. The soil temperature predicted by the model are in good agreement with the corresponding experimental data, and the maximum relative errors are 14.2%.