梯形旋流排沙渠道水沙特性  

Water and sediment characteristics in a trapezoidal desilting channel with a swirling flow generator

作　　者：南军虎[1] 徐超 李伟 杜尚武 胡红玲 代江龙 陶然 NAN Junhu;XU Chao;LI Wei;DU Shangwu;HU Hongling;DAI Jianglong;TAO Ran(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050

出　　处：《农业工程学报》2024年第24期117-126,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(52069011);兰州市青年科技人才创新项目(2023-QN-33)。

摘　　要：为揭示不同来流条件下梯形旋流排沙渠道的水沙特性,采用模型试验的方法,研究了梯形旋流排沙渠道在不同来流流量、加沙量、来沙中值粒径以及流速下的水沙运动规律和排沙特性,分析了分流比、截沙率与余沙率的变化规律。结果表明,当来流流量或者来流流速增大时,梯形旋流排沙渠道的截沙率减小,下游渠道的余沙率增大,对排沙效果影响较为明显,试验条件下当来流流量由30 m^(3)/h增长到90 m^(3)/h时或者来流流速由0.57 m/s增长到1.60 m/s时,截沙率分别由92.97%减小至76.16%、92.97%减小至79.77%,余沙率分别由5.28%增大至21.38%、5.28%增大至18.77%;试验条件下当加沙量由300 g增大至700 g或者来沙中值粒径由0.315 mm增大到1.250 mm时,梯形旋流排沙渠道截沙率分别由92.97%增大至95.27%、89.53%增大至95.83%,截沙率变化幅度分别为2.30和6.30个百分点,余沙率分别由5.28%减小至2.85、8.64%减小至3.59%,余沙率变化幅度分别为2.43个百分点和5.05个百分点,表明加沙量与来沙中值粒径的改变对排沙效果的影响较小。在各水沙条件下梯形旋流排沙渠道均具有较好排沙效果,试验条件下其最小截沙率为76.16%,且对粒径区间>0.600~3.000 mm的泥沙颗粒的截沙率均不低于94.88%,因此能有效排出渠道内的有害泥沙。与同一水沙条件下的矩形断面相比较,梯形断面的旋流排沙渠道在保持截沙率相似的同时,分流比减小,且无明显淤积现象。该研究明确了梯形旋流排沙渠道的适宜性和高效性,可为其工程应用提供参考。This study aims to determine the water and sediment characteristics of the trapezoidal desilting channel with a swirling flow generator(TDCSFG)under different water and sediment conditions.The model test was also adopted to verify the water and sediment movement and sediment discharge of TDCSFG.Different conditions of water and sediment were then selected,such as incoming flow rates,mass of added sediment,median particle size of inflow sediment,and inlet flow velocities,as well as its split ratio.Finally,a systematic investigation was made to clarify the distribution of water consumption,sediment trapping efficiency,and residual sediment efficiency.The results show that there was a small water consumption for the sediment discharge,indicating the remarkable effect of desilting.Furthermore,the sediment carrying capacity of water flow increased significantly,as the flow rate or inlet flow velocities increased.The amount of suspended-load sediment increased,whereas,the bed-load sediment decreased in the bottom water layer.The sediment trapping efficiency of TDCSFG decreased,whereas,the residual sediment efficiency increased,indicating the outstanding influence on the sediment discharge.Once the incoming flow rates increased from 30 to 90 m^(3)/h or the inlet flow velocities increased from 0.57 to 1.60 m/s under experimental conditions,the sediment trapping efficiency decreased from 92.97%to 76.16%and 92.97%to 79.77%,respectively,where the variation ranges of sediment interception rate were 16.81%and 13.20%respectively;the maximum residual sediment efficiency increased from 5.28%to 21.38%and 5.28%to 18.77%,respectively,where the variation ranges of residual sediment efficiency were 16.10%and 13.49%,respectively.The most influence was concentrated mainly in the sediment with the particle size range of>0.075~0.315 mm.Once the mass of added sediment increased from 300 to 700 g or the median particle size of inflow sediment increased from 0.315 to 1.250 mm,there was an increase in the content of particle-size sediment in

关 键 词：旋流排沙渠道 梯形断面 试验 截沙率 余沙率 

分 类 号：TV91[水利工程—水利水电工程]