考虑开度变化的岩体粗糙裂隙热迁移特性研究OA

Taking the rough fractures of dry hot rock as the research object,based on indoor experiments and numerical simulation methods,different combinations of fracture seepage and heat transfer experiments were carried out.Results indicate that inlet injection velocity markedly affects both the rate of wall temperature decline and the final steady-state outlet temperature.Under high injection velocities,a greater temperature drop is observed,resulting in reduced heat exchange efficiency.In contrast,lower injection velocities yield a smaller temperature reduction,and enhanced thermal performance.Based on these experimental results,a 3-Dimensional numerical model considering shear effects was developed to simulate seepage and heat transfer in rough fractures to investigate how different stress affect fracture aperture and corresponding coupled hydro-thermal processes,revealing that stress variation will modify the contact patterns and alter the effective aperture.Specifically,non-contact regions serve as dominant flow pathways,where fluid transport and heat conduction are efficient,enabling rapid and extensive propagation of the thermal front.Conversely,in contact zones,fluid movement is impeded,leading to a"thermal barrier"effect.It can be observed that pronounced temperature gradients is along the fracture plane and delays in thermal front advancement,indicating that contact-induced aperture changes under stress conditions have a profound impact on the characteristics of seepage heat migration.These findings contribute to a deeper understanding of the coupled hydro-thermo-mechanical processes in fractured hot dry rocks.They also address key challenges related to heat transfer mechanisms and temperature field prediction,thereby providing scientific guidance for optimizing reservoir engineering strategies and advancing the commercialization of enhanced geothermal systems(EGS)hot dry rock geothermal energy.