相同尺寸管道双车在不同车间距下形成的缝隙流水力特性研究

发布时间：2018-06-24 20:43

本文选题：流量 + 间距　；参考：《太原理工大学》2014年硕士论文

【摘要】：随着科技和现代社会的飞速发展,我国的经济规模不断扩大,国民环保意识也随之不断增强。传统的交通运输方式—公路运输、铁路运输、水路运输和航空运输,已经不能满足现代社会的发展需求,而筒装料管道水力输送技术作为一种新型的节能环保的运输方式,是对现有交通运输方式的一种补充和完善,具有广阔的发展前景。本文结合国家自然科学基金项目“管道缝隙螺旋流水力特性研究(51109115)”和“管道列车水力输送能耗研究(51179116)”,采用理论分析和模型试验相结合的方法,在不同间距条件下,对管道双车的缝隙流进行分析研究及其水力损失进行了分析研究。得出主要结论如下： 1、流量相同间距变化时,在管道后车测试断面和管道前车测试断面,轴向流速分布具有以下特点：轴向流速随着测点距离管道中心距离的增大呈现先增后减,且随着间距增大,轴向流速梯度趋于稳定。同时,可以看出间距为50cm时轴向速度比间距为20cm和间距为80cm的轴向速度小。 2、流量相同间距变化时,在管道后车和前车测试断面,径向流速分布具有以下特点：间距为80cm时最为均匀,间距为50cm时次之,而间距为20cm时最不均匀随着间距的变化,径向流速分布密集区域基本一致,但是间距越大,密集区域越不明显。 3、流量相同间距变化时,在管道后车和前车测试断面,周向流速分布具有以下特点：间距为20cm下前车、后车周向速度分布最为均匀,流速梯度最小,间距为50cm的次之,间距为80cm时最不均匀,流速梯度最大。靠近管道内壁和管道车外壁的测点周向流速变化较大,不仅大小改变,方向也变化较大。随着间距的增大,前后车之间的影响越来越小。 4、流量相同间距变化时,车间断面的轴向流速分布有如下规律：间距为80cm时轴向流速分布,比间距为50cm和20cm时更为均匀,而间距为50cm和80cm时的管道前车断面轴向流速分布类似,间距为20cm时管道双车车间环隙轴向流速分布最不均匀,且与其他两个间距的分布相比有较大差异。同时,可以看出间距为50cm时轴向速度比间距为20cm和间距为80cm的轴向速度小。 5、流量相同间距变化时,车间断面的径向向流速分布有如下规律：径向流速分布密集区域基本趋于一致,径向流速分布随着间距的增大,有先密集后趋于稀疏的分布特征。 6、流量相同间距变化时,车间断面的周向流速分布有如下规律：间距为20cm下的双车车间环隙断面周向速度分布最为均匀,流速梯度最小,间距为50cm的次之,间距为80cm最不均匀,流速梯度最大。随着间距的增大,双车车间环隙断面周向流速分布的密集区域越来越明显。 7、相同流量下测试段内轴向速度的沿程分布图可以看出,对流量不同情况下,轴向速度在测试段内的变化基本可以分为4个阶段；从三个间距的速度沿程分布可以看出,双车之间相互影响的范围在35cm-50cm之间：间距过小,双车相互影响,导致轴向速度发生变化较大,周向和径向速度影响较大,导致能耗增加；间距过大,双车之间相互影响小,但是不经济且不利于实际运用。因此从这点考虑双车运行的最佳间距应在35cm-50cm之间。 8、在不同间距、不同流量的条件下,管道水流在测试段内水力损失变化趋势是一致的,即随着距离的增加,水力损失也不断的增加。在间距相同的情况下,流量越大,测试段内水流的水力损失也越大；管道水流经过第一个管道车时的水力损失小于管道水流经过第二个管道车时的水力损失。 9、当流量相同的情况下,间距不同,管道水流经过管道车时水力损失,随间距的增加先减小后增加,在本文中,间距为50cm时,水力损失最小,水力损失增幅亦最小；当间距为80cm时,水力损失最大,且水力损失增幅也最大。本文的研究成果,对筒装料管道水力输送技术的发展,具有重要的参考价值,为该技术的后续研究提供了宝贵的试验依据,也为提高输送效率、使其尽快实现工业化,提供了重要的理论依据。
[Abstract]:With the rapid development of science and technology and modern society , our country ' s economic scale is constantly expanding , and the consciousness of national environmental protection has been strengthened . Traditional modes of transportation - road transportation , railway transportation , waterway transportation and air transportation have not satisfied the development demands of modern society .

1 . At the same time , the axial flow velocity distribution has the following characteristics : axial flow velocity increases first and then decreases with the increase of the distance of the distance between the measuring point and the pipeline , and the axial velocity gradient tends to be stable as the distance increases . At the same time , it can be seen that the axial velocity is 20 cm and the axial velocity with the spacing of 80 cm is small as the spacing is 50 cm .

2 . The radial flow velocity distribution has the following characteristics : the spacing is 80 cm , the distance is 50 cm and the distance is 50 cm , and the distance is 20 cm . The radial flow velocity distribution is basically consistent with the change of spacing , but the larger the spacing , the less dense the dense area .

3 . When the flow rate is the same as that of the front vehicle , the distribution of the circumferential velocity of the front and rear vehicles has the following characteristics : the spacing is 20 cm , the velocity distribution is the most uniform , the velocity gradient is the smallest , the distance is 50 cm , the distance is 80 cm , the velocity gradient is the largest , and the velocity gradient is the biggest . The change of the velocity is not only the change of the size , but also the direction change . With the increase of the distance , the influence between the front and rear vehicles is smaller and smaller .

4 . At the same time , the axial velocity distribution of the cross section of the pipe is more uniform when the spacing is 80 cm , the axial velocity distribution is more uniform when the spacing is 50 cm and 20 cm , and the axial velocity distribution of the axial velocity of the pipe is not uniform when the spacing is 50 cm and 80 cm .

5 . The radial flow velocity distribution of the cross section of the workshop has the following rule : the radial flow velocity distribution is basically the same as that of the dense area , and the radial flow velocity distribution tends to be sparse with the increase of the spacing .

6 . At the same interval of flow , the circumferential velocity distribution of the cross section of the workshop has the following rule : the circumferential velocity distribution of the ring - gap section of the double - car workshop with the spacing of 20cm is the most uniform , the gradient of the flow velocity is the smallest , the spacing is 50 cm , the spacing is 80cm and the maximum velocity gradient is the maximum . As the distance increases , the dense area of the circumferential velocity distribution of the annular gap section of the double - vehicle workshop becomes more and more obvious .

7 . It can be seen that the change of axial velocity in the test section can be divided into 4 stages under different flow conditions .
It can be seen from the velocity distribution of three intervals that the mutual influence between the two vehicles ranges from 35 cm to 50 cm : the spacing is too small , the two vehicles interact with each other , resulting in a large change in the axial velocity , a large influence on the circumferential direction and radial velocity , which leads to an increase in energy consumption ;
The spacing is too large and the interaction between the two vehicles is small , but it is not economical and is not conducive to practical use . Therefore , the optimal spacing between the two vehicles should be between 35 cm and 50 cm in view of this point .

8 . Under the condition of different spacing and different flow , the change trend of hydraulic loss in the test section is consistent , that is , with the increase of distance , the hydraulic loss increases continuously . Under the same distance , the greater the flow rate , the greater the hydraulic loss of the water flow in the test section ;
The hydraulic loss when the pipe flow passes through the first pipe car is less than the hydraulic loss when the pipe water flows through the second pipeline vehicle .

9 . When the flow rate is the same , the distance is different , the hydraulic loss is decreased with the increase of the distance , the hydraulic loss is the least when the distance is 50 cm , and the increase of hydraulic loss is also the minimum .
When the spacing is 80cm , the hydraulic loss is the biggest , and the increase of hydraulic loss is also the biggest .

The research results of this paper have important reference value for the development of the hydraulic transport technology of the tube charging pipeline , which provides valuable experimental basis for the follow - up study of the technology , and also provides an important theoretical basis for improving the conveying efficiency and realizing industrialization as soon as possible .
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U171;TV134

【参考文献】