Journal of Jilin University(Earth Science Edition) ›› 2015, Vol. 45 ›› Issue (4): 1180-1188.doi: 10.13278/j.cnki.jjuese.201504204

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Effects of Variable Properties of Heat Transmission Fluid on EGS Heat Extraction: A Numerical Study

Cao Wenjiong, Chen Jiliang, Jiang Fangming   

  1. Laboratory of Advanced Energy System, CAS/ Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, CAS, Guangzhou 510640, China
  • Received:2014-10-29 Published:2015-07-26

Abstract:

The large changes to the temperature and pressure associated with EGS heat exploitation will lead to pronounced changes to the thermo-physical properties of the heat transmission fluid, which will in turn affect the fluid flow and heat transportation inside the EGS subsurface system. It is necessary to establish a variable thermo-physical property EGS model to simulate the EGS heat extraction process and to predict the performance of EGS including its lifetime and capacity. The present work is extended to a previously developed three dimensional EGS heat extraction model with considering the local thermal non-equilibrium between the rock matrix and fluid flowing in the fractures in the porous reservoir, by introducing a module modeling with the property variation of water and supercritical carbon dioxide (SCCO2). The model with fully coupled thermal and hydraulic actions is used to investigate the impacts of thermo-physical properties on the water-EGS heat extraction. It is found that the lifetime of the EGS is 9.0 a under the density effects and 7.5 a under the specific heat capacity effects, indicating that the larger the density and the specific heat capacity of the working fluid possessed are, the shorter the EGS's lifetime is. Under the viscosity effects, the lifetime of the EGS extends to 18.0 a, meaning that the larger the viscosity of the working fluid is, the longer the EGS can be operated. However, the thermal conductivity of working fluid hardly has any effect on the EGS performance. Specially, we compare the heat extraction performance of water-EGS and SCCO2-EGS. Under a fixed injection pressure, the lifetime of water-EGS is longer than that of SCCO2-EGS; but the extraction ratio of the former is lower than the latter at the same time instant mainly due to the much higher mass flow rate of the latter in the EGS operation.

Key words: enhanced geothermal systems, local thermal non-equilibrium, variable properties, supercritical carbon dioxide

CLC Number: 

  • TK529

[1] Tester J W, Anderson B J, Batchelor A S, et al. The Future of Geothermal Energy: Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century[R]. Cambridge: Massachussets of Institute of Technology, 2006.

[2] Yang Y, Yeh H. Modeling Heat Extraction From Hot Dry Rock in a Multi-Well System[J]. Applied Thermal Engineering, 2009, 29: 1676-1681.

[3] Gelet R, Loret B, Khalili N. A Thermo-Hydro-Mechanical Coupled Model in Local Thermal Non-Equilibrium for Fractured HDR Reservoir with Double Porosity[J]. Journal of Geophysical Research, 2012, 117: 7205-7228.

[4] Kalinina E, McKenna S, Hadgu T, et al. Analysis of the Effects of Heterogeneity on Heat Extraction in an EGS Represented with the Continuum Fracture Model[C]//Thirty-Seventh Workshop on Geothermal Reservoir Engineering, Stanford University. Stanford:CA, 2012:436-445.

[5] Jiang F M, Luo L, Chen J L. A Novel Three-Dimensional Transient Model for Subsurface Heat Exchange in Enhanced Geothermal Systems[J]. International Communications in Heat and Mass Transfer, 2013, 41: 57-62.

[6] Shaik A R, Rahman S S, Tran N H, et al. Numerical Simulation of Fluid-Rock Coupling Heat Transfer in Naturally Fractured Geothermal System[J]. Applied Thermal Engineering, 2011, 31: 1600-1606.

[7] Pruess K. Enhanced Geothermal Systems (EGS) Using CO2 as Working Fluid:A Novel Approach for Generating Renewable Energy with Simultaneous Sequestration of Carbon[J]. Geothermics, 2006, 3: 51-67.

[8] Pruess K. On Production Behavior of Enhanced Geothermal Systems with CO2 as Working Fluid[J]. Applied Thermal Engineering, 2008, 49: 1446-1454.

[9] 陈继良, 蒋方明. 增强型地热系统热开采性能的数值模拟分析[J]. 可再生能源, 2013, 31(12): 111-117. Chen Jiliang, Jiang Fangming. A Numerical Study on Heat Extraction Performance of Enhanced Geothermal Systems[J]. Renewable Energy Resources, 2013, 31(12): 111-117.

[10] 陈继良, 罗良, 蒋方明.热储周围岩石热补偿对增强型地热系统采热过程的影响[J]. 计算物理, 2013, 30(6): 862-870. Chen Jiliang, Luo Liang, Jiang Fangming. Thermal Compensation of Rocks Encircling Heat Reservoir in Heat Extraction of Enhanced Geothermal System[J]. Chinese Journal of Computational Physics, 2013, 30(6): 862-870.

[11] 陈继良, 蒋方明, 罗良. 增强型地热系统地下渗流场的模拟和分析[J]. 计算物理, 2013, 30(6): 871-878. Chen Jiliang, Jiang Fangming, Luo Liang. Numerical Simulation of Down-Hole Seepage Flow in Enhanced Geothermal System[J]. Chinese Journal of Computational Physics, 2013, 30(6): 871-878.

[12] Jiang F M, Chen J L, Huang W B, et al. A Three-Dimensional Transient Model for EGS Subsurface Thermo-Hydraulic Process[J]. Energy, 2014, 72: 300-310.

[13] The International Association for the Properties of Water and Steam. Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam[R]. Lucerne:International Association for the Properties of Water and Steam, 2007.

[14] The International Association for the Properties of Water and Steam. Lamda Release on the IAPWS Formulation 2011 for the Thermal Conductivity of Ordinary Water Substance[R]. Plzeň:International Association for the Properties of Water and Steam, 2011.

[15] The International Association for the Properties of Water and Steam. Viscosity Release on the IAPWS Formulation 2008 for the Viscosity of Ordinary Water Substance[R]. Berlin:International Association for the Properties of Water and Steam, 2008.

[16] 雷宏武, 李佳琦, 许天福, 等. 鄂尔多斯盆地深部咸水层二氧化碳地质储存热-水动力-力学(THM)耦合过程数值模拟[J]. 吉林大学学报:地球科学版, 2015, 45(2): 552-563. Lei Hongwu,Li Jiaqi,Xu Tianfu, et al. Numerical Simulation of Coupled Thermal-Hydrodynamic-Mechanical (THM) Processes for CO2 Geological Sequestration in Deep Saline Aquifers at Ordos Basin, China[J]. Journal of Jilin University: Earth Science Edition, 2015, 45(2): 552-563.

[17] Heidaryan E, Jarrahian A. Modified Redlich-Kwong Equation of State for Supercritical Carbon Dioxide[J]. The Journal of Supercritical Fluids, 2013, 81: 92-98.

[18] Span R, Wagner W. A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple Point Temperature to 1 100 K at Pressures up to 800 MPa[J]. Journal of Physical and Chemical Reference Data, 1996, 25: 1509-1596.

[19] Jarrahian A, Heidaryan E. A Novel Correlation Approach to Estimate Thermal Conductivity of Pure Carbon Dioxide in the Supercritical Region[J]. The Journal of Supercritical Fluids, 2012, 64:39-45.

[20] Heidaryan E, Hatami T H, Rahimi M, et al. Viscosity of Pure Carbon Dioxide at Supercritical Region: Measurement and Correlation Approach[J]. The Journal of Supercritical Fluids, 2011, 56: 144-151.

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