Heat Storage/Heat Release of Phase-Change Filling Body with Casing Heat Exchanger for Extracting Geothermal Energy  

作　　者：ZHANG Xiaoyan XU Muyan LIU Lang YANG Qixing KI-IL Song 

机构地区：[1]Energy School,Xi'an University of Science and Technology,Xi'an 710054,China [2]Key Laboratory of Western Mines and Hazards Prevention,Ministry of Education of China,Xi'an 710054,China [3]Department of Civil Engineering,Inha University,Incheon 402-751,South Korea

出　　处：《Journal of Thermal Science》2023年第3期1171-1189,共19页热科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51974225,51674188,51874229,51504182,51904224,51904225,51704229);Shaanxi Innovative Talents Cultivate Program-New-star Plan of Science and Technology(No.2018KJXX-083);Natural Science Basic Research Plan of Shaanxi Province of China(Nos.2018JM5161,2018JQ5183,2015JQ5187,2019JM-074);Scientific Research Program funded by the Shaanxi Provincial Education Department(Nos.15JK1466,19JK0543);China Postdoctoral Science Foundation(No.2015M582685);Outstanding Youth Science Fund of Xi’an University of Science and Technology(No.2018YQ2-01);the Scientific Research Program funded by Xi’an Science and Technology Bureau(No.201805036YD14CG20)。

摘　　要：Arranging heat exchanger in filling body to extract geothermal energy is an effective way to alleviate the problems of high ground pressure and high ground temperature in deep resource exploitation.Filling body with casing heat exchanger was acted as research object,encapsulating phase change materials(PCMs)in annular space.During heat storage and heat release process,the effects of different PCMs on temperature distribution,phase-change process and heat transfer performance were studied.The result indicates:During heat storage process,the temperature increases rapidly and the melting process is accelerated for the position closer surrounding rock.CaCl_(2)·6H_(2)O/EG can make filling body complete heat storage process in the shortest time because of its good thermal diffusivity.The heat storage capacity of PCMs backfill is significantly higher than that of ordinary backfill;it increases by 36.6%-67.3%at heat storage of 10 h.During heat release process,the closer to the heat exchange tube,the greater the temperature drop in filling body.The maximum value of heat release rate and heat release capacity is in CaCl_(2)·6H_(2)O/EG backfill,it can release 116.4%more heat than RT35backfill after heat release of 12 h,the maximum value of effectiveness and its heat transfer rate also is in CaCl_(2)·6H_(2)O/EG backfill.This paper provides the basic data for the selection of PCMs in phase-change thermal storage filling body.

关 键 词：flling body heat exchanger phase change material heat storage/heat release 

分 类 号：TD353[矿业工程—矿井建设] TK172[动力工程及工程热物理—热能工程]