Multiscale modeling of heat and mass transfer in fractured media for enhanced geothermal systems applications
Multiscale modeling of heat and mass transfer in fractured media for enhanced geothermal systems applications
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DOI：
10.1016/j.apm.2018.10.025
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发表时间：
2019-03
影响因子：
5
通讯作者：
M. Vasilyeva;M. Babaei;Eric T. Chung;D. Spiridonov
中科院分区：
文献类型：
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作者：
M. Vasilyeva;M. Babaei;Eric T. Chung;D. Spiridonov
在这项工作中，在一个假设的强化地热系统与复杂的裂缝网络的传热和传质被认为是。裂隙网络具有复杂的几何形状，存在于多个尺度中，对传热传质过程有着重要的影响。EGS操作的数值模型的预测能力直接依赖于如何准确地解决裂缝及其周围基质中的热量和质量传递。对于数值解，我们使用有限元近似生成细网格模型。精细网格明确地解决了裂缝;然而，该过程的模拟导致计算上禁止的模拟。为了降低方程组的维数，我们进一步扩展了广义多尺度有限元法（GMsFEM），以包括热传导方程。多尺度基函数的粗网格近似的方程构造和精确的解决方案，流体压力和温度得到的二维和三维模型问题。据作者所知，地热热回收作业的多尺度方法的应用很少。因此，开发的GMsFEM EGS应用程序将提供一个平台，开发预测工具，完全耦合热-水-机械-化学（THMC）过程。
In this work, heat and mass transfer in a hypothetical Enhanced Geothermal System with complex fracture network is considered. Fracture networks have complex geometries, exist in the multiple scales and have a significant impact on the heat and mass transfer processes. Predictive capacity of numerical models for EGS operations rely directly on how accurately the heat and mass transfer in fractures and their surrounding matrix are resolved. For numerical solution, we generate a fine grid model using finite element approximation. The fine grid explicitly resolves the fractures; however, simulation of the process leads to computationally prohibitive simulations. To reduce dimension of the system of equations, we further expand Generalized Multiscale Finite Element Method (GMsFEM) to include heat transfer equation. Multiscale basis functions for the coarse grid approximation of the equations are constructed and accurate solution fluid pressure and temperature are obtained for two and three-dimensional model problems. To the best knowledge of authors, there are only few application of multiscale methods for geothermal heat recovery operations. Therefore the developed GMsFEM for EGS applications will provide a platform to develop predictive tools for fully coupled thermo-hydro-mechanical-chemical (THMC) processes.