基于双U地埋管蓄取热耦合工况下土壤动态传热特性试验研究

Experimental Study on Dynamic Heat Transfer Characteristics of Soil Based on Double U-tube Buried Pipe Under Heat Storage and Release

为了探索蓄取热耦合工况下双U竖直地埋管周围土壤动态传热特性,自行搭建砂箱试验台,试验研究了蓄热取热耦合(冷热交替)运行模式对土壤温度分布和单位井深换热量的影响。试验结果表明:土壤温度随运行时间呈现出周期性上下波动的变化规律;随着径向距离增加,土壤温度上下波动幅度减小;单位井深换热量则呈现先急剧跃升后再下降趋于稳定,随后再急剧跃升的周期性变化规律;等功率、变蓄热功率和变取热功率三种工况中,连续运行模式下等功率工况的土壤温度上下波动幅度最小,而间歇运行模式下变取热功率工况的土壤温度上下波动幅度最小;连续运行模式下的平均单位井深换热量以等功率工况为最高,而间歇运行模式下的则以变蓄热功率工况为最高。

In order to explore the dynamic heat transfer characteristics of the soil around the double U vertical buried pipe under the conditions of heat storage and heat release coupling,the effects of operation modes of heating and cooling alternation on the soil temperature and the heat exchange capacity per meter were studied using a sandbox experimental system.The experiment results show that the soil temperature periodically fluctuated up and down with the running time.The fluctuation amplitude of soil temperature decreased with the increase of radial distance.The heat exchange capacity per meter showed a periodic change law that first jumps up sharply and then falls to be stable and then jumps up sharply.The fluctuation amplitude of soil temperature was the smallest under the condition of equal power in the continuous operation mode,the fluctuation amplitude of soil temperature was the smallest under the condition of variable heat power in intermittent operation mode.The average heat exchange capacity per meter was the highest under the condition of equal power in the continuous operation mode,whereas the average heat exchange capacity per meter was the highest under the condition of variable heat storage power in the intermittent operation mode.