Long-Term Thermal Performance of Group of Energy Piles in Unsaturated Soils under Cyclic Thermal Loading
Long-Term Thermal Performance of Group of Energy Piles in Unsaturated Soils under Cyclic Thermal Loading
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DOI：
10.3390/en14144122
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发表时间：
2021-07
期刊：
影响因子：
3.2
通讯作者：
A. Sani;R. Singh
中科院分区：
文献类型：
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作者：
A. Sani;R. Singh
地热能桩（GEPs）是一种环境友好的热交换技术，它将结构基础桩的作用双重化，用于负载支撑和满足建筑物加热/冷却需求。能量回路由高密度聚乙烯制成，允许载热流体循环，安装在桩基础元件中，以提取或注入并储存桩周围土壤中的热能。本文报道了一组能源桩嵌入在非饱和土壤（砂和粘土）在连续循环加热和冷却负荷下的长期行为的数值研究的结果。此外，还研究了两种情况：（1）对整个GEP进行集中加热和冷却;（2）交替加热和冷却堆。有人发现，在所有观察到的位置的温度幅度的趋势随着时间的推移而减少，作为连续的加热和冷却循环的结果。此外，与热活化组中的所有GEP相比，使交替的GEP经受加热和冷却循环导致较低的温度发展。这归因于所施加的热负荷，该热负荷是第一种情况下所考虑的热负荷的0.5倍。然而，这可能不是这样的情况下，相等的热负荷施加在GEP在两种情况下调查。
Geothermal energy piles (GEPs) are an environmentally friendly heat exchange technology that dualizes the role of the structural foundation pile for load support and in meeting the building heating/cooling need. Energy loops made from high-density polyethylene, which allow heat carrier fluid circulation, are fitted into the pile foundation elements to extract or inject and store heat energy in the soil surrounding the pile. This paper reports the results of a numerical study investigating the long-term behaviour of a group of energy piles embedded in unsaturated soils (sand and clay) under continuous cyclic heating and cooling load. Additionally, two scenarios were investigated where: (1) the whole GEPs were heated and cooled collectively; (2) alternate piles were heated and cooled. It was found that the trend of temperature magnitude at all the observed locations decreases with time as a result of the continuous heating and cooling cycles. Furthermore, subjecting alternate GEPs to the heating and cooling cycles result in lower temperature development in comparison to thermally activating all the GEPs in the group. This is attributed to the applied thermal load, which is 0.5 times that considered in the first case. However, this might not be the case where equal thermal load is applied on the GEPs in the two cases investigated.