Local heat transfer characteristics of water flowing through a single fracture within a cylindrical granite specimen

Bai, Bing; He, Yanlin; Li, Xiaochun; Hu, Shaobin; Huang, Xiaoxue; Li, Jun; Zhu, Jun

doi:10.1007/s12665-016-6249-2

Cited by 46 publications

(15 citation statements)

References 19 publications

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“…The heat transfer coefficient is a key parameter for heat transfer model when considering the local thermal non‐equilibrium between the fluid and the fracture surface. Studying heat transfer coefficient can help to optimize the numerical model of heat extraction and predict the HER . Therefore, theoretical analysis and experiments had been conducted to investigate the heat transfer coefficient .…”

Section: Introductionmentioning

confidence: 99%

Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems

Liu

et al. 2019

Energy Science & Engineering

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Supercritical CO 2 (SCCO 2 ) is considered as a promising alternative heat extraction fluid in the enhanced geothermal system (EGS) which can reduce atmospheric CO 2 emissions and water waste. However, the heat extraction performance of SCCO 2 is greatly affected by its thermophysical properties, which are high sensitivity to temperature/pressure. In this study, by considering the impacts of temperature and pressure on thermophysical properties of SCCO 2 , a thermo-hydro-mechanical coupling numerical model was established to investigate the effects of the initial reservoir temperature as well as the SCCO 2 injection pressure and temperature on heat extraction. The variations of reservoir permeability and mass productivity as well as the net heat extraction rate (HER) were simulated by implementing the model into COMSOL Multiphysics, which showed a good consistency compared with the hightemperature/pressure triaxial seepage experiments. Simulation results indicate that there are three distinct stages in mass productivity including the slow decline stage, the rapid increase stage, and the stabilization stage. Increasing the initial reservoir temperature or the injection temperature will reduce the net HER to varying degrees.Appropriate increase of the injection pressure and injection temperature can extend Stage 2 duration which can subsequently enhance the mass productivity and the net HER. Meanwhile, the higher injection pressure or the lower injection temperature will inhibit heat compensation within rock masses and accelerate the reservoir heat depletion. This study provides guidance for optimizing the injection parameters of CO 2 -EGS and aims to enhance the net HER while ensuring a reasonable reservoir production life. K E Y W O R D S enhanced geothermal system, heat extraction experiment, high temperature/pressure, numerical simulation, supercritical CO 2 How to cite this article: Li P, Wu Y, Liu J-F, et al. Effects of injection parameters on heat extraction performance of supercritical CO 2 in enhanced geothermal systems. Energy Sci Eng. 2019;7:3076-3094. https ://doi.

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Section: Introductionmentioning

confidence: 99%

Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems

Liu

et al. 2019

Energy Science & Engineering

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“…studied injectioninduced fracturing process in tight sandstone under different saturation conditions. Bai et al (2016) modeled local heat transfer characteristics of water flowing through a single fracture within a cylindrical granite specimen. Wei et al (2016) modeled the hydromechanical responses of sandwich structure faults during underground fluid injection.…”

Section: Enhanced Geothermal Systems (Egs) and Related Technologymentioning

confidence: 99%

Progress and perspectives of geothermal energy studies in China: from shallow to deep systems

et al. 2018

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“…Figure 1 shows the traditional heat extraction process from the geothermal system, where the vast rock fracture system is the main path for heat fluid flow. However, prediction of EGS service life and thermal energy extraction encounters considerable challenges due to limited knowledge of the heat exchange behavior between flowing fluid and high temperature rock [18][19][20][21]. Natural rock fractures are characterized by irregular shape, rough surface, and even contact asperities, which play important roles in the hydraulic and heat transfer properties of fractures.…”

Section: Introductionmentioning

confidence: 99%

“…Temperature contour of fracture profile with different JRC(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

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confidence: 99%

A Novel Procedure for Coupled Simulation of Thermal and Fluid Flow Models for Rough-Walled Rock Fractures

2021

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An enhanced geothermal system (EGS) proposed on the basis of hot dry rock mining technology has become a focus of geothermal research. A novel procedure for coupled simulation of thermal and fluid flow models (NPCTF) is derived to model heat flow and thermal energy absorption characteristics in rough-walled rock fractures. The perturbation method is used to calculate the pressure and flow rate in connected wedge-shaped cells at pore-scale, and an approximate analytical solution of temperature distribution in wedge-shaped cells is obtained, which assumes an identical temperature between the fluid and fracture wall. The proposed method is verified in Barton and Choubey (1985) fracture profiles. The maximum deviation of temperature distribution between the proposed method and heat flow simulation is 13.2% and flow transmissivity is 1.2%, which indicates the results from the proposed method are in close agreement with those obtained from simulations. By applying the proposed NPCTF to real rock fractures obtained by a 3D stereotopometric scanning system, its performance was tested against heat flow simulations from a COMSOL code. The mean discrepancy between them is 1.51% for all cases of fracture profiles, meaning that the new model can be applicable for fractures with different fracture roughness. Performance analysis shows small fracture aperture increases the deviation of NPCTF, but this decreases for a large aperture fracture. The accuracy of the NPCTF is not sensitive to the size of the mesh.

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Local heat transfer characteristics of water flowing through a single fracture within a cylindrical granite specimen

Cited by 46 publications

References 19 publications

Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems

Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems

Progress and perspectives of geothermal energy studies in China: from shallow to deep systems

A Novel Procedure for Coupled Simulation of Thermal and Fluid Flow Models for Rough-Walled Rock Fractures

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Local heat transfer characteristics of water flowing through a single fracture within a cylindrical granite specimen

Cited by 46 publications

References 19 publications

Effects of injection parameters on heat extraction performance of supercritical CO2 in enhanced geothermal systems

Effects of injection parameters on heat extraction performance of supercritical CO2 in enhanced geothermal systems

Progress and perspectives of geothermal energy studies in China: from shallow to deep systems

A Novel Procedure for Coupled Simulation of Thermal and Fluid Flow Models for Rough-Walled Rock Fractures

Contact Info

Product

Resources

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Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems

Effects of injection parameters on heat extraction performance of supercritical CO₂ in enhanced geothermal systems