Conventional piles embedded with geothermal loops, referred to as energy piles, have been successfully used as heat exchangers for the ground source heat pump system. For heating-dominated regions, it is crucial for the ground source heat pump system to keep the ground thermal balance in the long run. Solar energy is the most feasible source to charge the ground manually. In this study, thermal performance of an energy pile-solar collector coupled system for underground solar energy storage was investigated using numerical modeling. The results suggested that a lower flow rate should be adopted for the energy pile-solar collector coupled system to save the operational cost of the circulation pump. For the case with a pile length of 30 m, the decrease in the rate of solar energy storage was about 2% when the mass flow rate was reduced from 0.3 to 0.05 kg/s. Throughout a year, the maximum daily average rate of solar energy storage reached 150 W/m. It was also found that to increase the length and the diameter of the pile improved the thermal performance of the system by keeping its temperature relatively lower. In addition, the effects of the pile-pile thermal interference on reducing the rate of solar energy storage after a one-year operation were quantified to be within 10 W/m for groups with the pile-pile spacing of 3 times the pile diameter.

埋有地热回路的传统桩（称为能量桩）已成功用作地源热泵系统的热交换器。对于以加热为主的地区，从长远来看，对于地源热泵系统而言，保持地面热平衡至关重要。太阳能是手动充电的最可行方法。在这项研究中，使用数值模型研究了用于地下太阳能存储的能量堆-太阳能收集器耦合系统的热性能。结果表明，能量桩-太阳能集热器耦合系统应采用较低的流量，以节省循环泵的运行成本。对于桩长为30 m的情况，当质量流率从0.3降低到0时，太阳能存储率的降低约为2％。05公斤/秒 一年中，太阳能的最大日平均储能量达到150 W / m。还发现增加桩的长度和直径可以通过保持其温度相对较低来改善系统的热性能。此外，对于桩间距为桩直径的3倍的组，在一年运行后，桩热干扰对降低太阳能存储速率的影响被量化为10 W / m以内。