600 m超长综采工作面双采煤机采运匹配特性

Mining and transportation matching characteristics of 600 m super-long fully mechanized mining face with two shearers

  • 摘要: 超长综采工作面能够有效提高开采效率,但工作面加长后仍采用单采煤机作业会增加设备闲置时间,降低工作面的推进效率。为进一步提高综采工作面的开采效率,在600 m超长工作面的基础上设计双采煤机开采工艺,分析不同工艺刮板输送机的煤流强度和工艺参数。利用双采煤机之间能够协同配合开采的优势,设计双采煤机同向和对向开采工艺。利用建立的煤流时空分布模型分别获得单采煤机、双采煤机同向和对向开采工艺整个开采周期的刮板输送机煤流时空分布,分别从工艺周期、刮板输送机空载率、运载煤流最大截面积和体积、平均运载体积、运载体积波动系数和额定功率等方面对比了3种开采工艺。结果表明:双采煤机开采工艺能够降低刮板输送机空载率,提高资源利用率,降低煤流强度,降低刮板链疲劳断裂的风险。双采煤机对向开采工艺相比同向开采刮板输送机的最大运载体积较小,煤流强度更低,煤流体积波动系数更小,负载更稳定。通过7组对比仿真试验,探究了牵引速度对双采煤机对向开采工艺和刮板输送机煤流强度的影响。增大牵引速度比值会减小空载率,提高运行效率,反之则会降低。增大或减小牵引速度比值,会增大运载煤流最大截面积、最大运载体积和平均运载体积,加剧煤流体积的波动,增加刮板输送机额定功率,缩短开采周期,但2台采煤机的最小中心距不受影响。

     

    Abstract: Mining efficiency is effectively improved through the adoption of super-long fully mechanized longwall faces. However, when the face length is increased and single-shearer operation is retained, equipment idle time is increased and face-advance efficiency is reduced. To improve the mining efficiency of fully mechanized longwall faces, two-shearer mining processes are designed for 600 m super-long faces. Coal-flow intensity on the armoured face conveyor (AFC) and the associated process parameters are evaluated under various mining processes. Leveraging the cooperative mining of two shearers, mining processes of two shearers traveling in the same direction and opposite direction are proposed. A previously developed spatio-temporal distribution model of coal flow is used to simulate the spatio-temporal distributions of coal flow of the AFC under mining processes of single shearer, two-shearer in the same-direction and opposite-direction. Three mining processes are compared using process cycle time, no-load rate, peak cross-sectional area and volume of coal flow, average transport volume, volumetric fluctuation coefficient, and rated power required for the AFC. Under mining processes of two shearers, the AFC no-loading rate is reduced and resource utilization is improved. Coal-flow intensity is also decreased, and the risk of scraper chain fatigue fracture is reduced. Compared with the same-direction two-shearer mining process, a smaller conveyed coal volume is obtained under the opposite-direction two-shearer mining process. Lower coal flow intensity, a smaller volumetric fluctuation coefficient, and a more stable AFC load are also achieved. Effects of traction speed under two-shearer mining process in the opposite-direction and the coal-flow intensity on the AFC are investigated through seven sets of comparative simulation tests. When the traction-speed ratio is increased, the AFC no-load rate is reduced and operational efficiency is improved. When the ratio is decreased, the AFC no-load rate is increased and operational efficiency is reduced. When the traction-speed ratio is either increased or decreased, the maximum cross-sectional area of the conveyed coal flow is increased. Maximum conveyed coal volume and the average conveyed coal volume are also increased. Meanwhile, the volumetric fluctuation of coal flow is intensified, the AFC rated power is increased, and the mining cycle is shortened. However, the minimum center distance between two shearers remains unaffected.

     

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