化工学报 ›› 2023, Vol. 74 ›› Issue (S1): 223-234.DOI: 10.11949/0438-1157.20221552

• 流体力学与传递现象 • 上一篇    下一篇

基于裂隙粗糙性表征方法的地热岩体热流耦合数值模拟与分析

王志国(), 薛孟(), 董芋双, 张田震, 秦晓凯, 韩强   

  1. 东北石油大学土木建筑工程学院,黑龙江 大庆 163318
  • 收稿日期:2022-11-03 修回日期:2022-12-05 出版日期:2023-06-05 发布日期:2023-09-27
  • 通讯作者: 薛孟
  • 作者简介:王志国(1966—),男,博士,教授,dqwangzhiguo@126.com
  • 基金资助:
    国家自然科学基金项目(51706154);黑龙江省科学基金项目(E2018011)

Numerical simulation and analysis of geothermal rock mass heat flow coupling based on fracture roughness characterization method

Zhiguo WANG(), Meng XUE(), Yushuang DONG, Tianzhen ZHANG, Xiaokai QIN, Qiang HAN   

  1. School of Civil Engineering and Architecture, Northeast Petroleum University, Daqing 163318, Heilongjiang, China
  • Received:2022-11-03 Revised:2022-12-05 Online:2023-06-05 Published:2023-09-27
  • Contact: Meng XUE

摘要:

随着能源结构转型,干热岩等地热岩体得到了快速发展。地热岩体内部结构组成复杂,渗流与传热过程多变,如何针对岩体裂隙分布特征,建立更加精准的描述表征模型并进行多物理场耦合分析,有待深入探讨。基于裂隙粗糙性表征(joint roughness coefficient,JRC)描述方法,将表征单元体(representative elementary volume,REV)引入到JRC尺寸选取中,并将其应用于地热岩体物理模型中,采用数值模拟方法,对地热岩体温度场与渗流场进行了耦合分析。研究发现,裂隙附近温度场分布与裂隙的形态基本一致,表现出一种基岩温度场随着裂隙形态变化的波动性规律;流体注入速度和温度对系统运行达到稳态的时间影响呈负相关性;较低的注入速度和较高的注入温度都可以有效延长系统生产寿命,此外,通过对出口法向热通量的分析得出最佳注入流速。

关键词: 地热, JRC, 表征单元体, 传热, 传递过程, 数值模拟

Abstract:

With the transformation of energy structure, geothermal energy like dry hot rock has been rapidly developed. As the complex composite of the internal structure of the geothermal rock, as well as the changeable transfusion and heat transfer process, further discussion is needed as to how to establish a more accurate representation model and conduct multi-physical fields coupling analysis aiming at the distribution characteristics of rock fracture. Based on the description method of joint roughness coefficient (JRC), the representative elementary volume (REV) was introduced into the JRC size selection and it was applied into the geothermal rock physical model. The coupling analysis was conducted on the temperature field of geothermal rock and transfusion field by adopting numerical simulation method. It was found that the distribution of temperature field near the fracture was basically consistent with the fracture's morphology, showing a fluctuation law of the temperature field of bedrock with the change of the fracture morphology. There was a negative correlation between fluid injection speed and temperature on the time when the system reached steady state; both lower injection speed and higher injection temperature could effectively prolong the production life of the system; in addition, through the analysis of the outlet normal heat flux, it was concluded that the optimal injection velocity in this paper.

Key words: geothermal, JRC, representative elementary volume, heat transferr, transport processes, numerical simulation

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