Huang Laisheng, Wu Bing, Cai Haiwei, Li Chao, Wang Jingxin, Li Yang
School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; Institute for Emergency Rescue Ergonomics and Protection, China University of Mining and Technology (Beijing), Beijing 100083, China.
Sci Total Environ. 2024 Oct 20;948:174782. doi: 10.1016/j.scitotenv.2024.174782. Epub 2024 Jul 14.
Air leakage in goaf often leads to coal spontaneous combustion (CSC), which not only directly affects the safety production of mines but also causes significant environmental damage. Therefore, effectively sealing the airflow in goaf is crucial for preventing CSC. Feasibility experiments on using two-phase foam to seal air leakage in goaf were conducted, leveraging the advantages of large flow rate, wide diffusion range, and good accumulation characteristics of two-phase foam. The research results indicate that continuous injection of foam into loose media with maintained ventilation can completely seal the air leakage, with the foam capable of withstanding wind pressures of nearly 600 Pa. When the foam is used for one-time sealing with a length of 2 m, it remains effective for 60 min, and the sealing effectiveness improves with longer distances sealed against air leakage. Numerical simulation analysis and field measurements of airflow leakage in mine working faces reveal that effectively sealing the airflow passage in the goaf behind the corner of the return airway is crucial for preventing CSC. Two methods are proposed for sealing external airflow during coal mining: foam injection using a point drilling method near the heading and an incremental buried pipe injection method. Finally, the feasibility of two-phase foam sealing technology for goaf airflow leakage is analyzed from multiple perspectives including sealing effectiveness, practicality, economy, foaming process, and engineering implementation. The research findings provide new insights into goaf sealing technology, aiding in addressing safety and environmental issues caused by spontaneous combustion in goaf areas.
采空区漏风常常导致煤炭自燃，这不仅直接影响矿井安全生产，还会造成严重的环境破坏。因此，有效封堵采空区风流对于防止煤炭自燃至关重要。利用两相泡沫流量大、扩散范围广、堆积特性好的优点，开展了利用两相泡沫封堵采空区漏风的可行性试验。研究结果表明，在保持通风的情况下向松散介质中持续注入泡沫能够完全封堵漏风，该泡沫能够承受近600 Pa的风压。当泡沫用于一次性封堵长度为2 m时，其有效时间为60 min，且封堵漏风距离越长，封堵效果越好。通过对矿井工作面风流泄漏的数值模拟分析和现场实测发现，有效封堵回风巷隅角后方采空区的风流通道对于防止煤炭自燃至关重要。提出了两种采煤过程中外漏风封堵方法：在巷道附近采用点钻孔法注入泡沫和增量埋管注入法。最后，从封堵效果、实用性、经济性、发泡工艺和工程实施等多个角度分析了两相泡沫封堵采空区风流泄漏技术的可行性。研究结果为采空区封堵技术提供了新的思路，有助于解决采空区自燃引发的安全和环境问题。
