Numerical simulation on water injection/geothermal exploitation in collaboration with cooling ventilation roadway in deep mines
Synergetic mining of mine geothermal energy regulating the underground thermal environment is an active cooling method,which converts heat hazard control into geothermal utilization.To investigate the cooling characteristics of the roadway and heat recovery performance of the geothermal system,a multi-physical field mathematical model was established that incorporates the unsteady heat transfer of roadway and gas-liquid two-phase non-isothermal seepage in rock stratum.The accuracy of the numerical model was verified by the results of indoor similar simulation experiments.The results show that the cooling effect on surrounding rock with injected water lags behind the change of its water content.An obvious variation area of moisture content gradient exists at the edge of the saturated rock during the injected water seepage under the capillary action.After 70 d of water injection in rock,the decrease of airflow temperature in the roadway began to increase,and the average temperature of airflow in the roadway is 0.47℃lower than that without water injection at 400 d.The moisture content around the production well begins to increase gradually at 300 d,and the water content in the production well gradually increases after the negative pressure pumping.The water content in the production well reaches saturation at 500 d.The maximum heat production power reaches 82.33 kW after 270 d of geothermal production,and the accumulated heat production of the geothermal system reaches 6.28×1012 J after 1000 d.The production cycle of water injection and heat recovery in unsaturated rock stratum includes four processes in mines:migration and heat storage,high-temperature and low-production,high-temperature and high-production,and drop-temperature and reducing production.
heat hazard controlventilation and heat transfermine geothermalnumerical simulationdeep mining
万方数据
维普
