土壤温度季节性波动与热扩散率跃变对地埋管群取热性能的影响及其调和  

Influence and reconciliation of seasonal fluctuations in soil temperature and thermal diffusivity jumps on the thermal discharge performance of borehole heat exchangers

作　　者：巩振权 曲德虎 马兵善[1] 王刚[1] 厚彩琴[1] GONG Zhenquan;QU Dehu;MA Bingshan;WANG Gang;HOU Caiqin(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050

出　　处：《甘肃科学学报》2024年第6期129-136,共8页Journal of Gansu Sciences

基　　金：国家自然科学基金项目(52268018)。

摘　　要：为研究地质结构分层下不同影响因素对地埋管群取热性能的影响,建立了考虑土壤温度季节性波动的地埋管群数值传热模型,分析了土壤温度季节性波动、土壤热扩散率、钻孔间距、回填材料热扩散率和管群布置形式对管群取热性能的影响。结果表明,忽略土壤温度季节性波动将高估管群热效率和钻孔的单位管长换热量。管群位于多层土壤中,热扩散率高的土壤层冷堆积严重,钻孔间热相互作用更强,其中管群中心钻孔受热相互作用的影响最大。以矩形布置的钻孔群为例,当钻孔间距由3 m增加到5 m时,管群热效率可提升6.6%。同时,增大钻孔间距或使用高热扩散率回填材料均可增加单个钻孔的换热能力。然而,对确定的钻孔间距和管群构型,使用过高热扩散率的回填材料将降低管群的热效率。此外,线形布置的管群更适于短期连续运行的场景。To investigate the effects of different factors on the performance of a buried pipe group for heat extraction under stratified geological structures,a numerical heat transfer model was established to analyze the thermal performance of a pipe group under seasonal soil temperature fluctuations in this paper,accounting for factors such as soil thermal diffusivity,borehole spacing,backfill material thermal diffusivity,and pipe group layout.The results showed that neglecting the seasonal fluctuation of soil temperature could lead to overestimation of the thermal efficiency of the pipe group and borehole unit heat exchange rate.The pipe group was situated in multi-layered soil,where the soil layer with higher thermal diffusivity would accumulate more coldness,resulting in more intense thermal interaction between boreholes.The central borehole in the pipe group was most affected by thermal interaction.For a rectangular array of boreholes,increasing the borehole spacing from 3 m to 5 m resulted in 6.6% enhancement of the thermal efficiency of the pipe group.Increasing the borehole spacing or employing backfill material with high thermal diffusivity could increase the heat exchange capacity of individual boreholes.However,using excessively high thermal diffusivity backfill material for a given borehole spacing and pipe group configuration could decrease the overall heat efficiency of the pipe group.In addition,linear arrangement of pipe groups was found to be more suitable for short-term continuous operation scenarios.

关 键 词：竖直埋管换热器 季节性波动 热扩散率 回填材料 管群布局 

分 类 号：TK529[动力工程及工程热物理—热能工程]