To solve the problems of the large energy consumption and the low lump coal yield of the comprehensive mechanized coal mining(CMCM) for the shallowly buried hard and thick coal seam in the north of Shaanxi Province in the Jurassic period,the coal seam advancing hydraulic pre-splitting method is used for analyzing the influential factors of specific energy consumption at the CMCM face of lump coal creating.The method and approach for reducing the specific energy consumption and improving the lump coal rate at the hard and thick coal seam through the pulse water pre-splitting technique on the basis of optimizing the production process of coal seam have been proposed.The study on the pulse presplitting broken mechanism of the hard and thick coal seam reveals the deep-hole directional pulse presplitting failure law and analyzes the pre-splitting method and the process parameters of hydraulic rock fragmentation at different hard and thick coal seams.The study shows that coal hardness,coal seam fissures and joint development degree are the main factors affecting the specific energy consumption at CM-CM face of the lump coal mining.Through the field test of hydraulic pre-splitting at the representative large-height CMCM face of the shallowly buried coal seam of the Mine 5102 in the north of Shaanxi province,it is found that the cutting fracture linear density at the working face of coal wall increased by about 2 times,the coal cutter energy consumption reduced by 36％,the lump coal rate at the working face increased by 25％,and the coal dust concentration reduced by 35％ on average.Meanwhile,the working face of the large height CMCM coal wall spalling reduced after the advancing hydraulic presplitting.The test verifies the effectiveness of the pulse hydraulic pre-splitting technology in reducing the specific energy consumption and increasing the lump coal rate of the hard and thick coal seam.%为解决陕北侏罗纪浅埋厚硬煤层综采能耗大、块煤率低的问题,在优化煤层生产工艺基础上,采用煤层超前水压预裂的方法,分析了块煤制造综采面比能耗的影响因素,构建了通过脉冲水预裂技术来降低比能耗并提高厚硬煤层块煤率的方法和途径.通过对厚硬煤层脉冲水预裂破碎机理的研究,揭示了深孔定向脉冲水预裂煤体的破坏规律,分析了不同厚硬煤层水压破岩的预裂方法和工艺参数.研究表明:煤体硬度、煤层节理裂隙的发育程度是影响块煤制造综采面比能耗的主要因素.通过对陕北浅埋煤层典型大采高综采面开展水压预裂的现场试验,发现工作面煤壁截割裂隙线密度增加了约2倍,煤机截割能耗降低了36％,工作面的块煤率提高了25％,煤尘浓度平均降低了35％.同时超前预裂后大采高工作面煤壁片帮减少,试验验证了脉冲水预裂技术降低比能耗提高厚硬煤层块煤率的有效性.
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