地埋管换热器热短路现象的试验与模拟  

Field test and numerical simulation study on thermal short circuit of borehole heat exchanger

作　　者：毛汉川 李鹏[2] 毛官辉 李少华 吕清 MAO Hanchuan;LI Peng;MAO Guanhui;LI Shaohua;LV Qing(Geological Survey Institute of Zhejiang Province,Hangzhou 311203,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;Zhejiang Engineering Survey and Design Institute Group Co.,Ltd.,Ningbo 315012,China)

机构地区：[1]浙江省地质调查院,杭州311203 [2]中国地质大学(武汉),武汉430074 [3]浙江省工程勘察设计院集团有限公司,宁波315012

出　　处：《科技导报》2023年第12期94-100,共7页Science & Technology Review

基　　金：中国科学院学部咨询评议项目(2020-DX03-B-007)

摘　　要：浅层地埋管换热器是地源热泵系统的核心部分,其换热性能受众多因素的影响,地埋管换热器2支管之间存在的热短路现象就是其中之一。在地埋管的施工过程中,2支管之间的实际间距存在差异,导致不同程度的热短路,从而影响换热器的换热性能。基于实际地源热泵工程的热响应试验数据,建立了3D数值模型,研究了管间热短路对换热性能的影响。结果表明,增大2支管间的距离能显著提升地埋管换热器的换热性能,直径为32 mm的U型管换热器,2支管的最大轴心距离113 mm相较于最小距离33 mm的换热效率提高了22.7%,延米换热量与管轴心距之间呈线性关系式。Shallow geothermal energy is an important part of clean energy,and its development and utilization meet the needs of national and social development.The technology of ground source heat pump with borehole heat exchanger(BHE)is the main technology for developing shallow geothermal energy.BHE is the core part of ground source heat pump system(GSHP),and its heat transfer performance is affected by many factors.Because the distance between the two branches of the BHE is very small,there is a serious thermal short circuit phenomenon.In the construction process of BHE,the actual distance between two branches is unknown.And different spacing will lead to different degrees of thermal short circuit,which will affect the performance of BHE.Based on the thermal response test(TRT)of GSHP project,through the combination of field test and numerical simulation,a 3D numerical model is established to study the effect of thermal short circuit between two branches of BHE on its heat transfer performance.The results show that increasing the distance between the two branches can significantly improve the heat transfer performance of the BHE.The maximum distance of two branch pipes is 22.7%higher than that of the minimum distance.The linear relationship between heat exchange and branch distance in linear meter is presented.It is suggested that pipe clamps should be strictly used in the construction of buried pipes to ensure sufficient distance between the two branches.

关 键 词：地埋管换热器 热响应试验 热短路 

分 类 号：TU83[建筑科学—供热、供燃气、通风及空调工程]