Experimental study on seepage and heat transfer characteristics of single fracture granite under high-temperature cycle conditions

被引：0
|
作者：
Huang C. [1 ,2 ]
Liang W. [1 ,2 ]
Chen Y. [2 ]
Liao T. [1 ,2 ]
机构：
[1] College of Mining Engineering, Taiyuan University of Technology, Shanxi, Taiyuan
[2] Key Laboratory of In-situ Property-improving Mining, Ministry of Education, Taiyuan University of Technology, Shanxi, Taiyuan
来源：
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | 2023年 / 42卷 / 09期
基金：
中国国家自然科学基金; 国家杰出青年科学基金;
关键词：
geothermal mining; heat transfer characteristics; high-temperature cycle; high-temperature rock mass; rock mechanics; seepage flow in fracture;
D O I：
10.13722/j.cnki.jrme.2022.1210
中图分类号：
学科分类号：
摘要：
In the process of utilizing water injection heat exchange for the geothermal development of high-temperature rock mass，the surrounding high-temperature rock mass of the convective channel in the heat exchange will experience repeated cycles of cooling and heating. Under the cyclic temperature effect，the deformation of the fracture wall surface，fracture flow，and heat transfer characteristics of the high-temperature rock mass will be affected to a certain extent. To reveal the granite fracture seepage characteristics and forced convection heat transfer law in this complex process，the water seepage and heat transfer experiments were carried out in the laboratory under the cyclic cooling-heating process(300 ℃→250 ℃→200 ℃→150 ℃→300 ℃). The results showed that：(1) the injection of low-temperature water could induce damage and fracture of the high-temperature granite fracture surface. The roughness coefficient JRC of the fracture surface changed from the initial 14.51 to 21.03 after the cyclic process，and the maximum height difference ξ of the fracture surface profile increased from 2.2 mm to 3.21 mm. The flow-conducting fracture of the high-temperature rock mass became more tortuous and the roughness increased with the temperature change. (2) When the rock temperature decreased from 300 ℃ to 150 ℃，the fracture permeability decreased exponentially from the initial 1.63 Darcy to 0.53 Darcy. However，when the rock temperature increased from 150 ℃ to 300 ℃，the fracture closed due to the thermal expansion of the rock matrix，and the permeability further decreased. With the increase of the cooling-heating cycles，the overall fracture permeability fluctuated to a certain extent，eventually leading to a significant decrease in permeability. (3) A higher initial rock temperature and an increase in the injection water pressure for heat exchange were beneficial to the forced convection heat exchange effect of the high-temperature granite fracture. However，with the increase of the cooling-heating cycles，the effect of convection heat exchange weakened. This study has certain guiding significance and value for the efficient development of geothermal resources in the high-temperature rock mass and the control technology of convection heat exchange. © 2023 Academia Sinica. All rights reserved.
引用
收藏
页码：2253 / 2265
页数：12
相关论文
共 39 条
  • [1] LUND J W, TOTH A N., Direct utilization of geothermal energy 2020 worldwide review[J], Geothermics, 90, (2021)
  • [2] DUO Ji, The basic characteristics of the Yangbajing geothermal field：A typical high temperature geothermal system[J], Engineering Science, 5, 1, pp. 42-47, (2003)
  • [3] KANG Fangchao, Chun TANG, LI Yingchun, Et al., Challenges and opportunities of enhanced geothermal systems：A review[J], Journal of Engineering Science, 44, 10, pp. 1767-1777, (2022)
  • [4] LI Dewei, WANG Yanxin, Major issues of research and development of hot dry rock geothermal energy[J], Earth Science, 40, 11, pp. 1858-1869, (2015)
  • [5] XU Tianfu, YUAN Yilong, JIANG Zhenjiao, Et al., Hot dry rock and enhanced geothermal engineering：International experience and china prospect[J], Journal of Jilin University：Earth Science, 46, 4, pp. 1139-1152, (2016)
  • [6] YASUHARA H, KINOSHITA N, OHFUJI H, Et al., Temporal alteration of fracture permeability in granite under hydrothermal conditions and its interpretation by coupled chemo-mechanical model[J], Applied Geochemistry, 26, 12, pp. 2074-2088, (2011)
  • [7] KAMALI-ASL A，, GHAZANFARI E, PERDRIAL N，, Et al., experimental study of fracture response in granite specimens subjected to hydrothermal conditions relevant for enhanced geothermal systems[J], Geothermics, 72, pp. 205-224, (2018)
  • [8] JIN Peihua, HU Yaoqing, SHAO Jixi, Et al., Experimental study on physico-mechanical and transport properties of granite subjected to rapid cooling[J], Chinese Journal of Rock Mechanics and Engineering, 37, 11, pp. 2556-2564, (2018)
  • [9] FENG Z，, ZHAO Y，, ZHANG Y，, Et al., Real-time permeability evolution of thermally cracked granite at triaxial stresses[J], Applied Thermal Engineering, 133, pp. 194-200, (2018)
  • [10] ZHAO Jian, Experimental study of flow-rock heat transfer in rock fractures[J], Chinese Journal of Rock Mechanics and Engineering, 18, 2, pp. 119-123, (1999)
1234