深海采矿扬矿泵参数设计及模拟研究

发布时间：2018-09-10 12:27

【摘要】：深海蕴藏着丰富的矿产资源,对缓解我国资源短缺危机具有十分重要的现实意义。在深海矿产资源开采系统中,扬矿提升泵是其中的关键环节。扬矿提升泵不仅要提供输送流体的动力,即扬程,还要使粒径达20-50mm的粗颗粒矿石得以通过。已有研究表明半轴流泵是目前可行的泵型,可满足大流量、高扬程的要求。我国虽于“十一五”期间成功研制出深潜硬管提升两级泵,然而颗粒在泵内的堵塞问题尚未得到根本解决。分析泵体部件相关参数与颗粒参数之间的匹配关系,揭示提升泵内粗颗粒固-液两相运动机理,对于扬矿提升泵设计开发具有重要的理论意义和现实意义。基于现有扬矿提升泵的研究成果,对扬矿泵的叶轮和导叶进行水力设计；数值模拟和物理模型相结合,研究扬矿泵外特性和内部流动特性,分析了叶轮叶片安放角对扬矿泵性能的影响；利用离散相数值模型和物理模型,研究了不同粒径颗粒在扬矿泵中运动特性,分析叶轮叶片进口安放角对颗粒运动特性的影响；利用物理模型研究了颗粒在扬矿泵内的堵塞特性。具体结论如下：(1)扬矿泵最优工况点流量为28 m3/h,扬程为4.8 m,水力效率为66%,与设计工况点吻合,符合初始设计要求；叶轮静态下泵进、出口压差的数值模拟结果与实验值相比,误差不超过10%,表明了数学模型的有效性和可靠性。(2)对叶轮叶片进口安放角加上10°的冲角后,扬矿泵最优工况点流量为25 m3/h,扬程为4.8 m,水力效率为61%,泵的扬程和效率整体下降,最高效率点向小流量方向偏移。(3)颗粒在叶轮区域呈现螺旋上升运动,随着粒径的增大,颗粒与叶轮碰撞几率增大,碰撞点向叶轮头部趋近；颗粒在导叶区域经过2-4次碰撞流出导叶,碰撞位置主要分布于导叶背面入口、导叶工作面中部以及导叶背面出口。叶轮叶片进口安放角的增大使得颗粒在叶轮流道中的轨迹向叶轮工作面偏移,且更加平滑。颗粒在导叶流道中的分布更加分散。(4) 随着颗粒粒径增大,颗粒的导叶进口速度减小,过泵时间增大；较大的导叶进口角导致颗粒与导叶碰撞次数增加,较大过泵时间导致颗粒在泵中容易聚集进而发生堵泵。(5) 一定浓度颗粒过泵时,随着清水流速的减小,颗粒逐渐在导叶入口处发生堵塞。颗粒粒径越大,发生堵泵时的清水临界流速越大,
[Abstract]:The deep sea is rich in mineral resources, which is of great practical significance to alleviate the crisis of resource shortage in China. In the mining system of deep-sea mineral resources, the lifting pump is the key link. The lifting pump should not only provide the power of conveying fluid, I. e., lift, but also make the coarse grained ore with diameter up to 20-50mm pass through. Studies have shown that the semi-axial flow pump is a feasible pump type, which can meet the requirements of large flow rate and high head. Although the two-stage pump was successfully developed in China during the "11th Five-Year Plan" period, the problem of particle plugging in the pump has not been solved fundamentally. By analyzing the matching relationship between the relative parameters of the pump body and the particle parameters, it is of great theoretical and practical significance for the design and development of the lifting pump to reveal the mechanism of solid-liquid motion of coarse particles in the lifting pump. Based on the research results of the existing lifting pump, the hydraulic design of the impeller and guide vane of the hoisting pump is carried out, and the external and internal flow characteristics of the lifting pump are studied by the combination of numerical simulation and physical model. The influence of impeller blade placement angle on the performance of lifting pump is analyzed, and the movement characteristics of different particle sizes in the pump are studied by using discrete phase numerical model and physical model, and the influence of impeller blade inlet placement angle on particle motion characteristics is analyzed. The plugging characteristics of particles in lifting pump are studied by using physical model. The specific conclusions are as follows: (1) the optimal flow rate of the lifting pump is 28 m3 / h, the head is 4.8 m, the hydraulic efficiency is 66 m, which is consistent with the design conditions, and conforms to the initial design requirements, and the numerical simulation results of the pump inlet and outlet pressure difference under the static condition of the impeller are compared with the experimental values. The error is not more than 10, which shows the validity and reliability of the mathematical model. (2) after the impeller blade inlet angle is added with a 10 掳angle of attack, the optimal working point flow rate of the lifting pump is 25 m3 / h, the lift is 4.8 m, the hydraulic efficiency is 61%, and the head and efficiency of the pump as a whole decrease. The maximum efficiency point deviates to the direction of small flow rate. (3) the particle appears spiral ascending motion in the impeller region. With the increase of particle size, the probability of particle and impeller collision increases, and the collision point approaches to the impeller head; The particles flow out of the guide vane 2-4 times in the guide vane area, and the collision position is mainly distributed in the back entrance of the guide vane, the middle part of the guide vane face and the back outlet of the guide vane. With the increase of impeller blade inlet angle, the trajectory of particles in the impeller passage is shifted to the impeller face, and it is smoother. (4) with the increase of particle size, the inlet velocity of the particle decreases and the pump time increases, and the larger inlet angle of the guide vane leads to the increase of the number of collisions between the particles and the guide vane. The larger over pump time leads to the accumulation of particles in the pump and the blockage of the pump. (5) with the decrease of the flow rate of clear water, the particles become clogged at the inlet of the guide vane. The larger the particle size is, the higher the critical flow rate of clean water is when the pump is blocked.
【学位授予单位】：中央民族大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD53

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