Experimental study on thermal-hydraulic-mechanical coupling of rock mass in water-conducting fault co-exploiting of coal and geothermal energy
The high permeability of water-conducting fault rock mass provides a new idea for efficient co-exploiting of coal and geothermal energy.The permeability evolution law of fault rock mass under deep thermal-hydraulic-mechanical(THM)coupling condition has become a prerequisite for the realiza-tion of co-exploiting of coal and geothermal energy.The THM triaxial test system was independently de-veloped and the permeability test of water-conducting fault fractured rock mass was carried out under the coupling effect of THM.The test results show that seepage process of rock mass under THM coupling can be divided into 2 stages:stage of erosion to increase permeability,stage of volume reduction to re-strain flow.Among them,the stage of erosion to increase permeability occurred in the initial stage of the test,and the porosity,velocity and permeability of the fractured rock mass increased rapidly in this stage,and then kept small fluctuations in stage of volume reduction and to restrain flow.The thermal ex-pansion effect caused by high temperature inhibits the expansion of pore space,as a result,the permea-bility parameters grow slowly in the Stage of erosion to increase permeability.The higher water pressure is,the greater the increase of permeability in the stage of erosion to increase permeability,indicating that the erosion effect of high water pressure is more significant.Both axial and confining pressure can cause the volume reduction effect of rock mass in fractured zone and inhibit the erosion effect of seepage,and lead to the decrease of permeability of the sample.This paper enriches the research on THM coupling characteristics of water-conducting fault rock mass,and provides laboratory test basis for efficient co-ex-ploiting of coal and geothermal energy.
co-exploiting of coal and geothermal energyfault rock massthermal-hydraulic-mechanical coupling characteristicseffects of erosion
万方数据
维普
