深部矿井岩层注水采热协同巷道通风降温数值模拟研究  

Numerical simulation on water injection/geothermal exploitation in collaboration with cooling ventilation roadway in deep mines

作　　者：徐宇 王运敏 李孜军[1] 李刚[1,3] 刘华森[1] XU Yu;WANG Yunmin;LI Zijun;LI Gang;LIU Huasen(School of Resources and Safety Engineering,Central South University,Changsha 410083,China;Department of Architecture and Civil Engineering,City University of Hong Kong,Hong Kong 999077,China;State Key Laboratory of Safety and Health for Metal Mines,Maanshan 243000,China)

机构地区：[1]中南大学资源与安全工程学院,长沙410083 [2]香港城市大学建筑与土木工程系,中国香港999077 [3]金属矿山安全与健康国家重点实验室,马鞍山243000

出　　处：《中国有色金属学报》2024年第10期3518-3531,共14页The Chinese Journal of Nonferrous Metals

基　　金：香江学者计划资助项目(XJ2023039);国家自然科学基金资助项目(52274247);湖南省自然科学基金资助项目(2022JJ30050);金属矿山安全与健康国家重点实验室开放基金项目(2022-JSKSSYS-03)。

摘　　要：矿井地热开采调控井下热环境是将热害治理转变为热能利用的主动降温方法。为研究矿井非饱和含水岩层注水采热下巷道降温特征及地热系统采热性能,建立了巷道通风-岩层气液两相渗流非等温传热多场耦合数值模型,并利用室内物理实验验证了模型准确性。结果表明:岩层注水对巷道围岩降温作用滞后于引起的围岩含水率变化,毛细作用下注入水在岩层内渗流迁移过程中形成明显的含水率梯度变化区域。岩层注水70 d后,巷道内风温下降幅度开始增大,在400 d时巷道风流平均温度比无注水措施时低0.47℃。生产井周围岩体含水率在300 d时开始逐渐增加,启动生产井负压抽采后,生产井中的含水率逐渐增大,在第500 d时生产井中含水量达到饱和。生产井抽采270 d后产热功率达到最大值82.33 kW,地热系统运行1000 d后累计产热量达到6.28×10^(12)J。矿井非饱和岩层注水采热周期包括迁移蓄热、高温低产、高温高产、降温降产四个过程。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 6.28×10^(12) 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.

关 键 词：热害治理 通风传热 矿井地热 数值模拟 深部开采 

分 类 号：TD727[矿业工程—矿井通风与安全]