Numerical investigations of enhanced shallow geothermal energy recovery using microencapsulated phase change materials and metal fins
Numerical investigations of enhanced shallow geothermal energy recovery using microencapsulated phase change materials and metal fins
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DOI：
10.1007/s11440-022-01715-1
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发表时间：
2022-12
期刊：
影响因子：
5.7
通讯作者：
Yimin Lu;Douglas D. Cortes;X. Yu;G. Narsilio;S. Dai
中科院分区：
文献类型：
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作者：
Yimin Lu;Douglas D. Cortes;X. Yu;G. Narsilio;S. Dai
浅层地热能的开采效率受到换热器周围短期温度异常和长期地热耗竭的双重制约。本研究提出了显着改善能源桩的热性能的数值研究，通过使用微胶囊相变材料（mPCM）和金属翅片在地面上。一个三维的水热有限元模型的能量桩嵌入在地面的开发，验证，并扩展到考虑相变和潜热在地面上评估的热性能的能量桩在各种地面条件下。结果表明，在土壤中掺入少量的相变材料，利用其潜热，可以显著提高能量的采集量和效率。在季节性操作期间，从砂-mPCM混合物中回收的能量是仅砂的两倍，是纯颗粒mPCM地面的三倍。此外，砂-mPCM混合料地基的温度影响区明显收缩。此外，在能量堆周围安装金属翅片可以加速与远场的热传导，进一步提高热回收效率。这项研究揭示了高效和环保的地热能回收利用相变材料。
The efficiency of shallow geothermal energy recovery has been constrained by both the short-term temperature anomaly around heat exchangers and the long-term ground heat depletion. This study presents numerical investigations of significant improvement in the thermal performance of energy piles by using microencapsulated phase change materials (mPCM) and metal fins in the ground. A three-dimensional hydrothermal FEM model of an energy pile embedded in the ground is developed, validated, and extended to consider phase change and latent heat in the ground to evaluate the thermal performance of the energy pile under various ground conditions. The results show that both the energy harvest amount and efficiency can be evidently improved by mixing small proportions of mPCM in the ground to utilize its latent heat. The recovery energy from the sand–mPCM mixture is twice that of just sand and thrice that of the pure granular mPCM ground during seasonal operations. Moreover, the temperature influence zone is significantly shrinked in the sand–mPCM mixture ground. In addition, installing metal fins around the energy pile can accelerate heat conduction with the far field and furtherly improve the heat recovery efficiency. This study sheds light on efficient and environmentally friendly geothermal energy recovery using phase change materials.