文献类型：期刊文献

英文题名：Coupled thermal-hydraulic-mechanical model for an enhanced geothermal system and numerical analysis of its heat mining performance

作者：Zhou, Luming[1,2];Zhu, Zhende[1,2];Xie, Xinghua[3];Hu, Yunjin[4]

机构：[1]Hohai Univ, Key Lab, Minist Educ Geomech & Embankment Engn, Nanjing 210098, Peoples R China;[2]Hohai Univ, Jiangsu Res Ctr Geotech Engn Technol, Nanjing 210098, Peoples R China;[3]Nanjing Hydraul Res Inst, State Key Lab Hydrol Water Resources & Hydraul En, Nanjing 210029, Peoples R China;[4]Shaoxing Univ, Key Lab Rock Mech & Geohazards Zhejiang Prov, Shaoxing 312000, Peoples R China

年份：2022

卷号：181

起止页码：1440

外文期刊名：RENEWABLE ENERGY

收录：SCI-EXPANDED(收录号：WOS:000709777500008)、、EI(收录号：20214211023790)、Scopus(收录号：2-s2.0-85116939082)、WOS

基金：This work was funded by the Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province (Grant No. ZJRMG-2020-04 ) and The National Natural Science Foundation of China (NSFC) (Grant Nos. 41831278 , 51878249 and 51579081 ). The authors would like to thank all the reviewers who participated in the review and MJEditor ( www.mjeditor.com ) for its linguistic assistance during the preparation of this manuscript.

语种：英文

外文关键词：Enhanced geothermal system; Thermal-hydraulic-mechanical coupling process; Hot dry rocks; Average production temperature; Heat extraction ratio

外文摘要：The operation of an enhanced geothermal system (EGS) involves a complex thermal-hydraulic-mechanical (THM) coupling process, which is important for exploiting the geothermal energy contained in hot dry rocks. In this study, the THM coupling mechanism in an EGS reservoir is explained, and a fully coupled THM mathematical model with local thermal nonequilibrium of a dual media is established, considering the dynamic changes in the properties of the rock matrix, fractures, and fluid during EGS operation. The model is verified through an example of the thermoelastic consolidation of a saturated soil. The heat transfer, fluid flow, and mechanical characteristics of a geothermal reservoir over 40 years are studied via a numerical simulation of a 2D geometric model. The effects of fracture occurrence, coupling conditions, and model parameters on the mining performance are analyzed. The results show that the dual-media model can reflect the anisotropy in the temperature, pressure, and stress due to the presence of fractures. An area with a more complex fracture network and smaller spacing is found to be more conducive for heat transfer. The inlet-outlet pressure differences, thermal expansion coefficient of the rock matrix, and initial fracture permeability have significant effects. When the inlet-outlet pressure difference is increased from 4 to 10 MPa, the heat extraction ratio increases from 56% to 89% at 40 years, and the initial output thermal power is increased from 9.2 to 24.9 MW. When the coefficient of thermal expansion is increased from 1 x 10(-6) to 7 x 10(-6) K-1, the heat extraction ratio is increased from 54% to 84%, and the initial output thermal power is increased from 8.5 to 19.7 MW. When the initial permeability is increased from 1 x 10(-11) to 2.5 x 10(-11) m(2), the heat extraction ratio increases from 74% to 92%. These results provide a reference for optimizing the mining effect of the EGS. (c) 2021 Elsevier Ltd. All rights reserved.