针对能源桩桩内温度场分布特征开展了现场原位试验,实测获得了能源桩换热过程中的桩壁和桩心温度,以此为基础结合数值模拟分析了能源桩的桩内温度场分布特征及其影响因素。分析结果表明:能源桩桩内温度温升规律与地埋管进出口温度变化规律一致,桩内温度场主要受地埋管进出口温度控制;能源桩制热(冷)时,以地埋管为起点,桩内温度远离地埋管呈抛物线下降(上升);影响能源桩桩内温度场分布特征的主要因素为回填材料导热系数和桩径,导热系数越大,相同制热时间时的桩内温度越高,且桩心温度随导热系数的增加近似呈线性上升;桩径越大,相同制热时间时的桩内温度越低,桩内温度随桩径的增加近似呈等比例下降。该研究成果可为能源桩的推广应用提供参考。

In the present research, the characteristics and influence factors of temperature field distribution in energy piles with buried spiral pipe were investigated by numerical means based on field prototype tests on temperature field distribution in energy piles as well as measured values of temperatures at pile wall and pile core during heat exchange. Results reveal that the regularity of temperature rise in energy pile is consistent with temperature variation at the inlet and outlet of buried pipe, which suggest that temperature field in energy pile is mainly dominated by temperature at the inlet and outlet of buried pipe. When energy pile is heated or refrigerated, temperature in pile declines or rises in a parabola along the way of the buried pipe. Moreover, the conductivity coefficient of backfill material and the pile diameter are two main factors affecting the temperature field distribution in energy pile. As conductivity coefficient increases, the temperature in pile rises at given heat durations; and in particular, temperature at the core of pile rises linearly. As pile diameter increases, the temperature in pile declines in equal proportion at given heat durations. The research results could be taken as reference for the promotion of energy piles.