一种废弃矿井地热资源再利用系统研究

Research on a reuse mode of geothermal resources in abandoned coal mines

废弃矿井的再利用对矿业产业的可持续发展起着至关重要的作用。矿井废弃后仍赋存着丰富的资源,有潜在的积极用途,尤其是大量可再生地热资源有着巨大的应用前景。分析了国外废弃矿井地热资源开采与利用现状,提出了一种废弃矿井地热资源利用循环系统模型,该系统利用顶板垮落后采空区的储水优势,能够充分利用废弃矿井地热、水及空间资源,进行清洁能源的生产,避免了矿井废弃后资源的浪费与次生灾害的发生,同时可有效地降低温室气体排放和环境污染。研究结果表明:倾向长度350 m,走向长度4000 m,高度6 m近水平工作面采空区的储水能力约为580000 m^(3),静态储能约为5200 MW·h;考虑不同地层采空区的温度特性,设置冷热源水库,整个系统运行时功率可达8.4 MW,年供能约24960 MW·h,可约为250000 m^(2)住宅空间进行有效的供暖或制冷。与传统化石能源煤炭相比,系统运行时每年可减少约为7812 t二氧化碳排放,碳排放系数仅为0.072 kg/(kW·h),降低了81%以上。此外,相关部门应建立健全废弃矿井的管理机构,提前做好矿井关闭前再利用计划。同时,矿业企业要做好再利用的技术储备与措施,实现废弃矿井的再利用,推动采矿区域环境恢复和经济复苏。

The reuse of abandoned coal mines plays a vital role in the sustainable development of the mining in-dustry.Abandoned coal mines still contain abundant resources with potentially positive benefits,especially in the generation of large amounts of renewable geothermal energy,with great prospects for application.The paper ana-lyzed the current situation of geothermal resource exploitation and utilization in abandoned mines overseas and proposed a circulatory system model for geothermal resource utilization in abandoned mines by taking advantage of the water storage in the backward mining area after the roof collapse.Moreover,the system can make full use of geothermal energy,water and space resources in abandoned mines to produce clean energy,avoid waste of resources and disasters in abandoned mines,and effectively reduce greenhouse gas emissions and environmental pollution.The research results reveal that the water storage capacity of the goaf of a coal seam with a face length of 350 m,a strike length of 4000 m,and a height of 6 m is 580000 m^(3),and the static energy storage is 5200 MW·h.Considering the temperature characteristics of different strata mining areas,setting up the cold and heat source reservoirs,the entire system can operate with a power of 8.4 MW,supplying the energy of about 24960 MW·h per year and providing effective heating or cooling for about 250000 m^(2)of residential space.Compared to traditional fossil fuel coal,the system can reduce carbon dioxide emissions by approximately 7812 t per year,with a carbon emission factor of only 0.072 kg/(kW·h),a reduction of more than 81%.In addition,some relevant departments should be established and the management of abandoned mines should be improved,and it should be make plans to reuse mines in advance of their closure.Also,it is important for the coal enterprises to maintain the appropriate technical resources to facilitate the reuse of the abandoned mines and promote the environmental and economic recovery in the mining regions.