Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8075180 | Energy | 2015 | 13 Pages |
Abstract
Hot dry rock geothermal energy is almost inexhaustible green energy. However, it makes slow progress in practice due to slow theory development. In this study, a three dimension thermo-hydro-mechanical coupled model of fractured media was established to simulate the extraction of HDR (Hot dry rock) geothermal energy based on the geological characteristics (geothermal gradient of 50Â K/km, buried depth of 6250-6750Â m) of Tengchong geothermal field in China. The simulation results show the variation in both field of temperature, stress, seepage and fracture aperture during heat extraction. The temperature in fracture face increased exponentially from injection well towards production well while extracting heat. The initial rock mass temperature of 573Â K decreases to 423Â K after 9-year running. The initial water pressure gradient in the fracture reached 0.17Â MPa/m near the injection well and then decreased to 0.052Â MPa/m after 1 year. The fracture aperture was triple of the initial value and the permeability coefficient increased by nine times over the 9-year operation period. That seepage resistance of artificial storage reservoir gradually decreased could improve extracting geothermal energy more efficiently. The amount of extracted heat declined exponentially with running time. The total extracted geothermal energy over 9 years was 5977Â MWa and rock mass temperature decreased to 423Â K.
Related Topics
Physical Sciences and Engineering
Energy
Energy (General)
Authors
Yangsheng Zhao, Zijun Feng, Zengchao Feng, Dong Yang, Weiguo Liang,