Convective heat transfer of water flow in intersected rock fractures for enhanced geothermal extraction

作     者：Yuedu Chen Zhihong Zhao Huan Peng Yuedu Chen;Zhihong Zhao;Huan Peng

作者机构：Department of Civil EngineeringTsinghua UniversityBeijing100084China 

出 版 物：《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报（英文版）)

年 卷 期：2022年第14卷第1期

页      面：108-122页

核心收录：

学科分类：070801[理学-固体地球物理学] 07[理学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 

基　　金：financially supported by the National Key R&D Program of China(Grant No.2019YFB1504103) the China Postdoctoral Science Foundation(Grant Nos.2019TQ0174) 

主　　题：Heat transfer Fracture intersection Fluid flow Rough fracture Geothermal extraction 

摘      要：Numerous intersected rock fractures constitute the fracture network in enhanced geothermal *** complicated convective heat transfer behavior in intersected fractures is critical to the heat recovery in fractured geothermal reservoirs.A series of three-dimensional intersected fracture models is constructed to perform the flow-through heat transfer *** geometry effects of dead-end fractures(DEFs)on the heat transfer are evaluated in terms of intersected angles,apertures,lengths,and the *** results indicate that annular streamlines appear in the rough DEF and cause an ellipse distribution of the cold *** to plate DEFs,the fluid flow in the rough DEF enhances the heat *** the increment of outlet water temperatureΔToutand the ratio of heat production Qrpresent the largest at the intersected angle of 90°while decline with the decrease of the intersected angle between the main flow fracture(MFF)and the *** extension of the length of intersected DEFs is beneficial to heat production while enhancing its aperture is not *** increasing the number of intersected DEFs induces a little increase of heat extraction,and more significant heat production can be obtained through connecting these DEFs with the MFF forming the flow network.