能源桩传热特性与热-力响应研究综述

A review on heat transfer performance and thermal-force response of energy piles

能源桩将地源热泵系统与传统桩基结合,具有换热效率高、占用空间少和成本低等优点。梳理近年来关于能源桩的传热和承载性能两个方面的研究进展,分析能源桩传热性能的影响因素及机理、热—力耦合状态下的结构响应及传热、结构响应的数值模型。在此基础上,提出能源桩下一步的研究建议与展望。分析指出:螺旋形管体的换热面积最大,换热效率最佳;在循环剪切作用下,能源桩的桩—土界面侧摩阻力衰减,使桩基承载力不断弱化;此外,一个周期中的制冷/制热需求不均可能引起地表温度失衡,从而影响换热效率。能源桩的优化设计及长期服役的可靠性将是未来研究的重点。

Energy pile combines the ground source heat pump system with the traditional pile foundation,which has the advantages of high heat exchange efficiency,less space occupation and low cost.This paper summarizes the latest research results on heat transfer and bearing performance of energy piles at home and abroad,and analyzes the influencing factors and mechanism of heat transfer performance,structural response under thermalforce coupling and numerical models of heat transfer and structural response of energy piles.Based on this basis,the next research suggestions and prospect of energy pile are put forward.The analysis indicates that the largest heat exchange area of the spiral tube and the best heat exchange efficiency;under the action of cyclic shear at the pile-soil interface,the lateral friction resistance attenuates,which continuously weakens the bearing capacity of the energy piles.Moreover,the uneven refrigeration/heating demand in one cycle may cause the surface temperature imbalance,thus affecting the heat exchange efficiency.Therefore,the optimized design of energy piles and the reliability of long-term service will be the focus of future research.