分层土壤中竖直埋管换热器传热特性
2015年12月 CIESC Journal ·4836·
December 2015第66卷 第12期 化 工 学 报 V ol.66 No.12
分层土壤中竖直埋管换热器传热特性
张琳琳1，赵蕾1，杨柳2
（1西安建筑科技大学环境与市政工程学院，陕西 西安 710055；2西安建筑科技大学建筑学院，陕西 西安 710055) 摘要：基于移动有限长线热源理论，考虑土壤分层及存在渗流现象，建立了埋管传热解析模型。利用热响应试验
验证了该模型的正确性。对比分层模型与均质模型所给出的埋管散热过程的土壤温度响应表明：埋管周围土壤沿
轴向分层使其温度分布也呈现分层而非均匀的特点，各层土壤中钻孔壁处温度趋于稳定所需的时间及数值因各层
物性的差异而不同。对整个埋管区土壤均质或分层但存在渗流作用以及部分土壤层存在渗流作用等3种情况进行
了计算分析，发现：若整个分层土壤中存在渗流，而视土壤为均质并忽略渗流的影响，则对换热能效系数低估可
达6.3%；埋管散热在各土壤层中的热作用距离因存在渗流与否偏差可达43%。可见，为了准确评估钻孔周围渗流
作用下分层土壤中的温度分布特性，应利用分层模型计算各土壤层中的热作用距离，以最大值确定管间距，否则
会导致管群布置时管间距选取偏小。
关键词：地埋管换热器；传热；热响应试验；移动线热源；土壤分层模型；地下水渗流；试验验证
DOI ：10.11949/j.issn.0438-1157.20150818
中图分类号：TK 521 文献标志码：
A 文章编号：0438—1157（2015）12—4836—07
Heat transfer characteristics of vertical borehole heat exchanger in stratified soils
ZHANG Linlin 1, ZHAO Lei 1, YANG Liu 2
(1School of Environmental and Municipal Engineering , Xi ’an University of Architecture and Technology , Xi ’an 710055, Shaanxi ,
China ; 2School of Architecture , Xi ’an University of Architecture and Technology , Xi ’an 710055, Shaanxi , China )
Abstract: An analytical heat transfer model was established for a borehole heat exchanger (BHE) with single U-tube in stratified soils based on the moving finite line heat source model, taking the factors such as soil stratifications and groundwater advection into account. This model was validated by the data obtained in an on-site soil thermal response test. The soil temperature responses to the BHE heat injection were obtained by using this model and homogeneous model. Comparison of these two sets of results indicates that the soil temperature around the BHE along axial direction is not uniformly distributed due to the characteristics of soil stratification. It takes different length of time for the borehole wall temperature to reach stable and to maintain at a different stable temperature in every layer, due to the difference of physical properties of soil in each layer. Three cases are calculated and analyzed for homogeneous soil, stratified soil with groundwater advection in whole soil domain, and stratified soil with groundwater advection in some soil layer. It shows that the heat transfer efficiency coefficient is underestimated up to 6.3% if ignoring the soil stratification and the influence of groundwater advection. The thermal effect distance deviation in each soil layer may be up to 43% for cases with and without groundwater advection. In order to assess the soil temperature distribution characteristics around the BHE with the
2015-06-03收到初稿，2015-09-06收到修改稿。
联系人：赵蕾。第一作者：张琳琳（1988—），女，博士研究生。
基金项目：国家科技部科技支撑计划课题(2014BAJ01B01)。 Received date : 2015-06-03. Corresponding author : Prof. ZHAO Lei, leizhao0308@https://www.wendangku.net/doc/2c3829196.html, Foundation item : supported by the National Key Technology R&D
Program of the Ministry of Science and Technology (2014BAJ01B01).