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    煤矸石浆体多工况条件流动特性的试验研究

    Experimental study on flow characteristics of coal gangue slurry under multiple working conditions

    • 摘要: 为研究多工况条件下管道内煤矸石浆体的流动特性,采用中试环管试验及数值模拟方法,研究了不同浆体浓度、流量及管径对煤矸石浆体流动特性的影响规律。研究结果表明,直管段中,沿程阻力损失与浆体流量成正比,随浓度增加、管径减小而增大;上坡段阻力损失最大,第二组上下坡段损失较小。特殊管段中,阻力损失随流量和浓度增加而小幅增大,随管径增大而减小。入口截面速度分布均匀,出口截面因重力呈“圆心下沉”剖面,管壁处流速最低。浓度增大使浆体结构强度增大,保持良好流动性;流量增大使“流核区”向中心集中且面积扩大,同时管壁低速区扩大;管径增大则使“流核区”面积减小。上下坡段中,受惯性影响,高速流动区分别下移和上移,该现象也随管径的增大而减弱。

       

      Abstract: To investigate the flow characteristics of coal gangue slurry in pipelines under multiple operating conditions, a combination of a pilot-scale ring pipe test and numerical simulation was employed. The effects of slurry concentration, flow rate, and pipe diameter on the flow behavior of coal gangue slurry were systematically analyzed. The results indicate that, in straight pipe sections, the resistance loss along the way is positively correlated with the slurry flow rate, and it increases with increasing slurry concentration and decreasing pipe diameter. The resistance loss is greatest in the uphill section, whereas that in the second set of alternating uphill and downhill sections is comparatively lower. In special pipe sections, the resistance loss increases slightly with increasing flow rate and concentration, while it decreases with increasing pipe diameter. Furthermore, the velocity distribution at the inlet cross-section is relatively uniform, whereas at the outlet cross-section it exhibits a "central subsidence" profile due to gravitational effects, with the minimum flow velocity occurring near the pipe wall. An increase in slurry concentration enhances the structural strength of the slurry while maintaining favorable flowability. As the flow rate increases, the “flow core region” becomes more concentrated toward the pipe center and expands in area, accompanied by an enlargement of the low-velocity zone near the pipe wall. In contrast, an increase in pipe diameter leads to a reduction in the area of the “flow core region.” In the uphill and downhill sections, the high-velocity flow region shifts downward and upward, respectively, due to inertial effects; moreover, this phenomenon becomes less pronounced with increasing pipe diameter.

       

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