粗颗粒矿石在深海采矿系统软管中输送特性试验研究

发布时间：2018-11-15 11:26

【摘要】：利用管道将海底矿石提升到海面是目前最清洁高效的深海采矿方式。软管段是深海采矿系统中连接中继仓和集矿机的关键环节,受力学特性、海底地形及回采工艺等多种约束条件的影响,其空间形态复杂,对输送工艺和参数匹配要求比较严格。论文基于深海采矿软管输送模拟试验系统,分析了不同工况条件下软管形态动态变化特征及其规律,根据软管空间形态分析了不同工况条件下软管输送参数特征,提出深海采矿系统输送参数优化方法。主要工作和结论如下：(1)深入分析了泵体对于管道内流速和压力分布的影响。安装在软管之前的泵为其提供正压,安装在软管之后的泵为其提供负压,双泵串联时,管道压力有相互抵消的作用,最大负压降低到单泵控制时的1/2,最大正压降为单泵控制时的1/5。管内内流流速增大,最大流速比单泵控制时约增加了1/3。试验时,为避免软管内部出现负压,应使主管泵保持在较低转速,而调节软管泵转速以达到试验需求。(2)确定了软管空间形态与集矿车移动距离、内流流速和内流特性之间的关系。当拱顶高度不受水面高度限制时,集矿车移动距离增大和内流流速增加均使软管拱顶高度和曲率线性增加；而当内流为浆体时,软管形态变化趋势与内流为清水时一致,但软管拱顶高度和曲率增幅均小于清水内流,原因在于包含粗颗粒的浆体密度远远大于清水密度,单位流体重力增幅大于垂向冲力的增幅,因此,软管隆起高度和曲率均比内流为清水时偏小,且两侧下垂更加明显。(3)建立了颗粒粒径、颗粒体积浓度、内流流速、管道形态和水力坡度之间的定量关系。复杂形态软管中粗颗粒输送水力坡度随着颗粒物料的体积浓度增加而增加,随混合物流速增加而增加,随颗粒粒径增加而降低,此规律与众多水平及倾斜管道研究结果一致。此外,当倾斜角度差别不大时,随着软管弯曲度增大,颗粒紊动动能增加,水力坡度随之增加。对比分析软管及倾斜管道中阻力损失关系,利用量纲分析法并结合试验实际情况,提出了软管阻力损失计算公式。(4)探究了粗颗粒浆体安全输送速度的影响因素及其定量关系。研究发现,软管安全输送速度随着浆体体积浓度、颗粒粒径增加而增加,但随着软管拱顶上升,倾斜角度增加反而降低。对比软管实测安全输送速度及倾斜直管安全输送速度关系,利用量纲分析法并结合试验实际情况,提出了软管安全输送速度计算公式。其研究结果可为深海采矿输送参数优化提供参考,在实际采矿过程中,可根据集矿机位置合理设计软管输送速度,以确保软管处于最佳输送状态。
[Abstract]:It is the cleanest and most efficient deep-sea mining method to raise seabed ore to sea surface by pipeline. Hose section is the key link of connecting relay bin and ore collector in deep sea mining system. It is affected by mechanical characteristics, submarine topography and mining process, and its spatial form is complex, and the matching requirements of transportation technology and parameters are relatively strict. Based on the simulation test system of hose transportation in deep sea mining, this paper analyzes the dynamic characteristics and rules of hose morphology under different working conditions, and analyzes the characteristics of hose transport parameters under different working conditions according to the spatial configuration of hose. A method for optimizing transportation parameters of deep sea mining system is presented. The main work and conclusions are as follows: (1) the influence of pump body on velocity and pressure distribution in pipeline is analyzed. The pump installed in front of the hose provides a positive pressure, and the pump installed behind the hose provides a negative pressure. When the two pumps are in series, the pipeline pressure is counteracting each other, and the maximum negative pressure is reduced to 1 / 2 of the control of the single pump. The maximum positive pressure drop is 1 / 5 of the single pump control. The flow velocity in the tube increases by about 1 / 3 of the maximum velocity compared with that of the single pump. In order to avoid the negative pressure inside the hose, the in-charge pump should be kept at a low speed, and the hose pump speed should be adjusted to meet the test requirements. (2) the space configuration of the hose and the distance between the moving distance of the collector and the hose should be determined. The relationship between flow velocity and flow characteristics. When the height of the vault is not limited by the water surface height, the height and curvature of the hose dome increase linearly with the increase of the moving distance and the flow velocity of the collecting truck. When the inner flow is the slurry, the change trend of the hose configuration is the same as that of the inner flow, but the height and curvature increase of the hose arch is smaller than that of the clear water, because the density of the slurry containing coarse particles is much larger than that of the clear water. The increase of gravity per unit fluid is larger than that of vertical impulse. Therefore, the height and curvature of hose bulge are smaller than those of clear water, and the droop of both sides is more obvious. (3) the particle size, particle volume concentration and flow velocity are established. Quantitative relationship between pipe shape and hydraulic gradient. The hydraulic gradient of coarse-particle conveying in the complex hose increases with the increase of the volume concentration of the particles, increases with the increase of the flow rate of the mixture, and decreases with the increase of the particle size, which is consistent with the research results of many horizontal and inclined pipelines. In addition, when the angle of inclination is not different, the kinetic energy of particle turbulence increases and the hydraulic gradient increases with the increase of the bend of the hose. By comparing and analyzing the relationship of resistance loss in hose and inclined pipe, using dimensional analysis method and combining with the actual situation of test, The formula for calculating the resistance loss of hose is put forward. (4) the factors affecting the safe conveying speed of coarse granular slurry and its quantitative relationship are discussed. It is found that the safe conveying speed of hose increases with the increase of slurry volume concentration and particle size, but with the increase of hose dome, the inclined angle decreases. Compared with the relation between the measured safe conveying speed of hose and the safe conveying speed of inclined straight pipe, a formula for calculating the safe conveying velocity of hose is put forward by using the dimensional analysis method and combining with the actual conditions of the test. The research results can provide a reference for the optimization of transportation parameters in deep-sea mining. In the actual mining process, the conveying speed of hose can be reasonably designed according to the position of the collector, so as to ensure that the hose is in the best state of transportation.
【学位授予单位】：中央民族大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD857

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