不同导流条长度管道车运移时的缝隙螺旋流流速特性研究

发布时间：2018-11-20 13:25

【摘要】：筒装料管道水力运输是一种环保、节能、高效安全的运输方式。该输送方式符合我国可持续发展的理念,是一种节能环保的新型管道水力输送方法。这种运送方法跟传统的浆体管道水力和型料管道水力运送方式有所区别,是一种新时代下极有研发前景的科学技术,具有非常广阔的应用发展前景。本文结合国家自然基金项目“管道列车水力输送能耗研究(51179116)”、“管道缝隙螺旋流水力特性研究(51109155)”和山西省自然科学基金项目(2015011067),通过试验和数值模拟相结合的方法,对不同导流条长度管道车运移时产生的缝隙螺旋流流速特性进行研究,得出如下结论:(1)当导流条长度为唯一变量时,管道车在管道内的运移速度随着导流条长度的增大而增大;当管道车的车型为唯一变量时,管道车运移速度从大到小依次为车型L×D=150×70mm管道车、L×D=100×70mm管道车、L×D=150×60mm管道车,由此可见管道车车径对运移速度的影响大于管道车的长度。(2)当不同导流条长度管道车在平直管段运移时,其缝隙内水流在靠近管道车车端的断面上水流速度分布稍有不同,主要表现在流速形成的涡区更多以及速度梯度变大。对于同一管道车,沿车身方向缝隙螺旋流的三维流速分布规律是由不稳定向稳定趋近,再逐渐变为不稳定。缝隙螺旋流的轴向速度分布相对于其径向和周向速度分布相对稳定,且轴向速度的数值也远大于缝隙流的径向和周向速度;导流条长度的增大会影响缝隙内水流径向流动的方向,导流条越长,方向为背离管道圆心的水流就越多;同种车型管道车随着导流条长度的增大,缝隙内各断面周向流速基本呈增大的趋势。(3)在其他工况不变的情况下,以车中断面3断面为研究断面,得出当极轴附近没有导流条存在时,缝隙螺旋流的轴向流速在离管道中心44mm处达到最大值,而当极轴附近有导流条的存在时,轴上的水流轴向流速变化趋势发生明显的变化,在布置的测环上,离管道中心越远,其轴向流速越大。(4)在其他工况不变的情况下,缝隙内测试断面极轴上的轴向速度沿车身方向分布规律基本相似,沿车身从车后断面到车前断面呈先增大后减小再增大再减小的“M”字型趋势。而缝隙螺旋流的径向和周向速度沿车身上测试断面的突变频率较高,并在4断面(车中和车前中间的断面)处出现较大的数值。(5)通过比较不同导流条长度管道车的平均运移速度、缝隙流平均速度和管道内水流的平均流速,得出了当导流条长度增大时,管道车运移平均速度和缝隙流平均流速的变化率,分析了不同导流条长度对管道车运移速度和缝隙流平均速度带来的影响。(6)通过数值模拟的方法,对不同导流条长度管道车在平直管段运移时的缝隙螺旋流流场的三维速度进行了计算模拟,并与试验结果进行了对比,结果基本一致。
[Abstract]:Hydraulic transportation of barrel-filling pipeline is an environmental-friendly, energy-saving, high-efficient and safe way of transportation. This transportation mode accords with the concept of sustainable development in our country and is a new type of pipeline hydraulic transportation method of saving energy and environmental protection. This transportation method is different from the traditional hydraulic transportation method of slurry pipeline and shaped material pipeline. It is a kind of science and technology with great prospect of research and development in the new era and has a very broad prospect of application and development. In this paper, the research on the energy consumption of pipeline train hydraulic transportation (51179116), the characteristics of helical flow force of pipeline gap (51109155) and the natural science fund project of Shanxi Province (2015011067) are combined with the National Natural Fund project "Research on Energy consumption of Pipeline Trains" (51179116). Through the combination of experiment and numerical simulation, the flow velocity characteristics of the slot helical flow produced by the pipeline vehicle with different diversion strip lengths are studied. The conclusions are as follows: (1) when the length of the guide strip is a unique variable, The moving speed of pipeline car in the pipeline increases with the increase of the length of the guide strip. When the vehicle type of pipeline vehicle is the only variable, the speed of pipeline vehicle moving from large to small is L 脳 DX 150 脳 70mm pipeline vehicle, L 脳 D0 100 脳 70mm pipeline car, L 脳 DX 150 脳 60mm pipeline car. It can be seen that the influence of pipeline car diameter on the moving speed is greater than the length of pipeline car. (2) when the pipeline car with different length of diversion strip moves in the straight section, The velocity distribution of the flow in the gap is slightly different in the section near the vehicle end of the pipeline, mainly because the vortex region formed by the velocity of velocity is more and the velocity gradient becomes larger. For the same pipe-car, the 3-D velocity distribution law of helical flow along the body direction is from instability to stability, and then to instability. The axial velocity distribution of the slot helical flow is relatively stable relative to its radial and circumferential velocity distribution, and the axial velocity is much larger than the radial and circumferential velocity of the slot flow. The increase of the length of the guide strip will affect the direction of the radial flow in the slot. The longer the strip, the more the flow direction deviates from the center of the pipe. With the increase of the length of the guide strip of the same type, the flow velocity of each section in the slot basically increases. (3) taking section 3 of the car as the research section, When there is no guide strip near the polar axis, the axial velocity of the slot helical flow reaches the maximum value at the point of 44mm from the center of the pipe, and when there is a guide strip near the polar axis, the trend of the axial velocity of the flow on the axis changes obviously. The farther away from the center of the pipeline, the greater the axial velocity is. (4) the axial velocity of the polar axis of the test section in the gap is similar to that of the body under the same conditions. Along the body from the rear section to the front section of the car showed a trend of "M" glyph, which increased first, then decreased and then decreased. However, the radial and circumferential velocity of the helical flow in the crevice is higher than that in the test section. At the four sections (the section in the middle of the vehicle and the middle section in the front of the vehicle), a large number of values appear. (5) by comparing the average moving speed, the average velocity of the slot flow and the average velocity of the flow in the pipeline, the average moving speed, the average velocity of the slot flow and the flow velocity in the pipeline are compared with each other. When the length of the guide strip increases, the change rate of the average velocity of the pipeline car and the average velocity of the slot flow is obtained. The influence of different length of guide strip on the moving speed and the average velocity of slot flow of pipeline vehicle is analyzed. (6) the method of numerical simulation is used. The 3-D velocity of the helical flow field in the slot of pipeline car with different length of diversion strip is simulated and compared with the experimental results, and the results are in good agreement with the experimental results.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV134

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