深层地埋管管群换热影响因素分析
Analysis of factors influencing heat transfer of deep-buried pipe groups
摘要：
为了揭示深层地埋管管群的换热机理,本文基于叠加原理建立了深层地埋管管群数值模型,并通过实测数据对模型进行了验证。通过对各地埋管取热量、年最低入口温度和周围土壤温度的分析,探究了地埋管布置方式、间距、深度和运行流量等因素对地埋管管群取热能力的影响。结果表明:单排布置时管群取热能力最大,但其热影响面积较大;随着地埋管间距的增大,管群的取热能力增大,第20年末,地埋管间距50 m的入口温度较10 m提高了13.76 ℃,推荐地埋管间距为30～40 m;当地埋管深度和运行流量增大时,管群的取热能力增大,但其增大的幅度逐渐减小;在设计地埋管深度和运行流量时,应考虑钻孔成本和循环泵功耗等,运行流量不应小于7 kg/s。
Abstract：
In order to reveal the heat transfer mechanism of deep-buried pipe groups, this paper establishes a numerical model of deep-buried pipe groups based on the superposition principle, and verifies the model through experimental data. By analysing the heat extraction from each buried pipe, the annual minimum inlet temperature of buried pipes and the soil temperature around the buried pipes, the influence of the factors such as the layout method of buried pipes, the spacing between buried pipes, the depth of buried pipes and the operating flow on the heat extraction capacity of buried pipe groups is explored. The results show that when the pipe group is arranged in a single row, the heat extraction capacity is the largest, but its heat influence area is large. With the increase of the spacing between buried pipes, the heat extraction capacity of pipe groups increases. At the end of the 20th year, when the spacing between buried pipes increases from 10 m to 50 m, the inlet temperature increases by 13.76 ℃, and the recommended spacing between buried pipes is 30 m to 40 m. When the depth of buried pipes and the operating flow increase, the heat extraction capacity of pipe groups increases, but the increase rate gradually decreases. When designing the depth of buried pipes and the operating flow, drilling costs and circulating pump power consumption should be considered, and the operating flow should not be less than 7 kg/s.
Keywords:deep-buried pipe; pipe group; heat extraction capacity; influencing factor; layout method; spacing between buried pipes; depth of buried pipe; operating flow