Numerical characterization of heat transfer in closed-loop vertical ground heat exchanger  

作　　者：Chulho LEE Hujeong GIL Hangseok CHOI Shin-Hyung KANG 

机构地区：[1]School of Civil,Environmental and Architectural Engineering,Korea University,5-Ga,Anam-Dong,Seongbuk-Gu,Seoul 136-713,Republic of Korea [2]Pyungsan SI Co.,Ltd.,1337-31 Seocho-Dong,Seocho-Gu,Seoul 137-860,Republic of Korea [3]Department of Mechanical Engineering,Konyang University,119,Deahak-Ro,Nonsan,Chungnam 320-711,Republic of Korea

出　　处：《Science China(Technological Sciences)》2010年第1期111-116,共6页中国科学（技术科学英文版）

基　　金：supported partially by the Construction Technology Innovation Program (Grant No.06CTIPD04) of Korea Institute of Construction and Transportation Technology Evaluation and Planning of the Ministry of Land,Transport;Maritime Affair and partially by the Fundamental Research and Development Program (Grant No.2008-N-GE08-R-01) of the Center of New and Renewable Energy of the Ministry of Knowledge and Economy of Korea

摘　　要：A series of numerical analyses has been performed on the characteristics of heat transfer in a closed-loop vertical ground heat exchanger(U-loop).A 2-D finite element analysis was conducted to evaluate the temperature distribution over the cross section of the U-loop system involving high-density polyethylene(HDPE) pipe/grout/soil to compare the sectional efficiency between the conventional U-loop and a new latticed HDPE pipe system,which is equipped with a thermally insulating lattice in order to reduce thermal interference between the inlet and outlet pipes.In addition,a 3-D finite volume analysis(FLUENT) was adopted to simulate the operation of the closed-loop vertical ground heat exchanger with the consideration of the effect of a distance between the inlet and outlet pipes,grout's thermal properties,the effectiveness of the latticed HDPE pipe system,and the rate of circulation pump.It was observed that the thermal interference between the two strands of U-loop is of importance in enhancing efficiency of the ground heat exchanger.Consequently,it is recommended to modify the configuration of the conventional U-loop system by equipping the thermally insulating lattice between the two pipe strands.A series of numerical analyses has been performed on the characteristics of heat transfer in a closed-loop vertical ground heat exchanger(U-loop).A 2-D finite element analysis was conducted to evaluate the temperature distribution over the cross section of the U-loop system involving high-density polyethylene(HDPE) pipe/grout/soil to compare the sectional efficiency between the conventional U-loop and a new latticed HDPE pipe system,which is equipped with a thermally insulating lattice in order to reduce thermal interference between the inlet and outlet pipes.In addition,a 3-D finite volume analysis(FLUENT) was adopted to simulate the operation of the closed-loop vertical ground heat exchanger with the consideration of the effect of a distance between the inlet and outlet pipes,grout’s thermal properties,the effectiveness of the latticed HDPE pipe system,and the rate of circulation pump.It was observed that the thermal interference between the two strands of U-loop is of importance in enhancing efficiency of the ground heat exchanger.Consequently,it is recommended to modify the configuration of the conventional U-loop system by equipping the thermally insulating lattice between the two pipe strands.

关 键 词：GROUND heat EXCHANGER HDPE PIPE latticed PIPE sectional efficiency 

分 类 号：TB657.5[一般工业技术—制冷工程]