坚硬特厚煤层顶煤冒放结构及提高采出率技术

针对西部埋深较浅、坚硬、特厚煤层顶煤冒放性差的问题,以金鸡滩煤矿2-2上坚硬特厚煤层赋存条件为基础,通过理论模型计算、数值模拟分析及设备结构优化设计等方法,分析了坚硬特厚煤层顶煤冒放结构及提高采出率技术。通过建立坚硬特厚顶煤的"悬臂梁"力学模型,计算分析了顶煤厚度与悬臂极限断裂长度的关系;首次定量分析了液压支架反复支撑对顶煤的损伤破坏效果,研究了液压支架主动支护作用力、反复支撑次数对顶煤破坏深度、破坏块度的影响;分析了大采高综放工作面煤壁片帮防治与提高顶煤冒放性的矛盾,通过优化液压支架架型结构参数解决了二者之间的矛盾;创新设计了强扰动三级高效放煤机构与综放工作面后部刮板输送机交叉侧卸布置方式,有效提高了大块顶煤的放出率与放出效率。

Top coal caving structure and technology for increasing recovery rate at extra thick hard coal seam

In order to overcome the poor caving property problem of extra thick hard coal seam with shallow depth in mining area of west China，the top coal caving structure and recovery rate improvement technologies were analyzed through theoretical model calculation，numerical modeling analysis and equipment structure optimization design based on the coal seam occurrence conditions at Jinjitan Coal Mine.Through building the cantilever beam model for extra thick hard coal seam，the relationship between the top coal thickness and the cantilever ultimate fracture length was analyzed and calculated.The damage effect from the repeating support of hydraulic support on the top coal was quantitatively analyzed for the first time，and the top coal damage depth and lumpiness from the active support reaction and support frequency of hydraulic support was studied.The contradiction between the rib spalling prevention and top coal recovery rate improvement was analyzed，which could be settled by optimizing the network structure of hydraulic support.Three level efficient top coal caving institution and the rear scraper conveyor cross side discharge arrangement were innovatively designed，which enhanced the top coal recovery rate and efficiency.