基于气力提升技术的河道泥沙输送试验研究  

Experimental study on sediment transport in river channel based on pneumatic lifting technology

作　　者：陈秋良 巫世晶[1] 李小勇[1] 王爱华[2] CHEN Qiuliang;WU Shijing;LI Xiaoyong;WANG Aihua(Key Laboratory of Hubei Province for Waterjet Theory&New Technology,Wuhan University,Wuhan,Hubei 430072,China;Comprehensive Engineering training Center of Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]武汉大学水射流理论与新技术湖北省重点试验室,湖北武汉430072 [2]武汉大学综合工程训练中心,湖北武汉430072

出　　处：《排灌机械工程学报》2018年第5期397-403,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：湖北省自然科学基金资助项目(2015CFA154);江苏省自然科学基金资助项目(BK20170411)

摘　　要：为了验证气力提升技术在河道清淤过程中的应用效果,依据70%浸没深度的普遍工况,搭建了采用气力提升技术的泥沙输送试验平台.在0~4.5 m/s的进气速度下,开展了泥沙提升效率试验,探究了最佳提升效率所对应的进气速度.同时基于Matlab图像处理功能,着重对0.6与1.0 m/s进气速度下的流型进行分析,得到了最佳提升效率附近对应流型的固体颗粒运动特性.研究结果表明,管内流型以及颗粒的运动特性直接受进气速度的影响.在浸没深度一定的情况下,河沙提升效率由进气速度所决定.通过研究不同进气速度下的流型,进而探究不同流型的形成原因,得知当进气速度达到1.0 m/s时,气相被充分离散成均匀细泡,气体与液固两相发生了强烈的动量交换,气体携带的绝大部分动能转移到了固液两相,该进气速度下的提升效率最高,此时的流型亦为气力提升最佳流型.通过测量得到清淤效率与进气速度的关系,验证了气力提升技术应用于河道清淤的可行性.In order to examine the effectiveness of pneumatic lifting technology in river dredging processes,a sediment transport test platform using the pneumatic lifting technology was set up based on the usual condition of 70%dimensionless immersion depth.At 0-4.5 m/s air inlet velocities,a series of pneumatic lift experiments were carried out to identify the air inlet velocity for the optimum lif-ting efficiency.Meanwhile,the flow patterns at different air inlet velocities,especially at 0.6 and 1.0 m/s,were analyzed based on the image processing function in Matlab.As a result,the solid particle motion characteristics near the optimum lifting efficiency were obtained.It is shown that the solid particle flow patterns and mention characteristics are directly affected by the air inlet velocity.In a fixed immersion depth,the sand lifting efficiency is determined by the air inlet velocity.By studying the flow patterns at various air inlet velocities,the reasons for the formation of different flow patterns have been clarified.When the inlet velocity is 1.0 m/s,the gas phase is fully dispersed into uniformly-sized small bubbles,and strong momentum exchanges take place in gas,liquid and solid phases.Consequently,most of the kinetic energy of the gas phase is transferred into the solid and liquid phases,and the lifting efficiency is the highest.At the same time,the flow pattern is also the optimum for airlift.Establishing the relationship between the dredging efficiency and the air inlet velocity by experimentation,the feasibility of pneumatic lifting technology in river channel dredging has been confirmed.

关 键 词：河道清淤 泥沙输送 气力提升技术 流型分析 进气速度 提升效率 

分 类 号：S277.9[农业科学—农业水土工程] TV1431[农业科学—农业工程]