Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(TH...Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(THMD)coupled model was developed to describe the coupling between rock damage and mechanical,fluid flow and heat transfer fields.The model considers rock heterogeneity,and incorporates the Mohr-Coulomb failure criterion and the maximum tensile stress criterion to evaluate shear and tensile damage.This numerical modeling methodology was first verified against analytical solutions and experimental results,and was then used to simulate the THMD coupling behavior in deep geothermal exploitation.A coupled numerical model was set up to simulate the geothermal fluids extraction and re-injection process in a reservoir at 1 km depth over a 7-year period.Rock damage was found to accelerate the propagation of cold fronts away from the injection well,and have a distinct effect on the performance of geothermal exploitation.When the rock damage was considered,the field injectivity increases by 8.4 times,the range of cooled regions increases by 18.6 times,and the vertical deformation changes by 1.2 times after 7 years of geothermal operations,compared to the scenario where it was not considered.Parametric studies have suggested that thermal contraction dominates the rock damage evolution,and that thermal-induced rock damage only occurs at a sufficiently large temperature difference between fluids injected and the reservoir.This work underscores the importance of accurately accounting for the damage effect on reservoir response during fluid injection activities that cause significant cooling of reservoir rocks.展开更多
A tuned hybrid-tanks/mass damper ( THMD) system is presented in this paper,and the equation of motion of structure-THMD system is formulated. A phasic difference analysis method is also presented to analyze the dynami...A tuned hybrid-tanks/mass damper ( THMD) system is presented in this paper,and the equation of motion of structure-THMD system is formulated. A phasic difference analysis method is also presented to analyze the dynamic effect of water in hybrid-tanks composed of TLCD and TLD on the control performance of THMD system. Numerical simulation is conducted and performances of an ordinary TMD,TLD,TLCD and THMD are compared under wind and earthquake excitation,respectively. Results show that the designed THMD can achieve a performance level close to that of the ordinary TMD,and outperforms TLD and TLCD. As compared with the ordinary TMD,THMD is more economical and practical.展开更多
The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-...The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine;TMHD=2,2,6,6-tetramethyl-3,5-heptanedionate).To provide a cohesive magneto-structural correlation,the mono bis(pyrazolyl)-tetrazine bridged congener[Dy_(2)^(Ⅲ)(μ-bpytz)(THMD)6]·4(C6H6)was also isolated.Both metal complexes exhibit single-molecule magnet behaviour under an applied dc field.展开更多
基金funded by the Major National Science and Technology Project for Deep Earth of China(Grant No.2024ZD1003805)the National Natural Science Foundation of China(Grant Nos.52311530070 and 52004015).
文摘Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(THMD)coupled model was developed to describe the coupling between rock damage and mechanical,fluid flow and heat transfer fields.The model considers rock heterogeneity,and incorporates the Mohr-Coulomb failure criterion and the maximum tensile stress criterion to evaluate shear and tensile damage.This numerical modeling methodology was first verified against analytical solutions and experimental results,and was then used to simulate the THMD coupling behavior in deep geothermal exploitation.A coupled numerical model was set up to simulate the geothermal fluids extraction and re-injection process in a reservoir at 1 km depth over a 7-year period.Rock damage was found to accelerate the propagation of cold fronts away from the injection well,and have a distinct effect on the performance of geothermal exploitation.When the rock damage was considered,the field injectivity increases by 8.4 times,the range of cooled regions increases by 18.6 times,and the vertical deformation changes by 1.2 times after 7 years of geothermal operations,compared to the scenario where it was not considered.Parametric studies have suggested that thermal contraction dominates the rock damage evolution,and that thermal-induced rock damage only occurs at a sufficiently large temperature difference between fluids injected and the reservoir.This work underscores the importance of accurately accounting for the damage effect on reservoir response during fluid injection activities that cause significant cooling of reservoir rocks.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 50608021)the Doctoral Fund of Ministry of Education of China(Grant No.20061078001)
文摘A tuned hybrid-tanks/mass damper ( THMD) system is presented in this paper,and the equation of motion of structure-THMD system is formulated. A phasic difference analysis method is also presented to analyze the dynamic effect of water in hybrid-tanks composed of TLCD and TLD on the control performance of THMD system. Numerical simulation is conducted and performances of an ordinary TMD,TLD,TLCD and THMD are compared under wind and earthquake excitation,respectively. Results show that the designed THMD can achieve a performance level close to that of the ordinary TMD,and outperforms TLD and TLCD. As compared with the ordinary TMD,THMD is more economical and practical.
基金the University of Ottawa,the CFI,the NSERC and the Academy of Finland(projects 315829,320015)for their financial supportConselho Nacional de Desenvolvimento Científico e Tecnológico(CNPQ,201395/2014-6)for a PhD scholarship.
文摘The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine;TMHD=2,2,6,6-tetramethyl-3,5-heptanedionate).To provide a cohesive magneto-structural correlation,the mono bis(pyrazolyl)-tetrazine bridged congener[Dy_(2)^(Ⅲ)(μ-bpytz)(THMD)6]·4(C6H6)was also isolated.Both metal complexes exhibit single-molecule magnet behaviour under an applied dc field.
