摘要
弯道后的水流调整不好,可导致进/出口存在严重偏流和水头损失增大.为了保证竖井式进/出水口的配水均匀性和水力稳定,采用三维RNG k-ε紊流模型,对某抽水蓄能电站上水库盖板竖井式进/出水口进行了数值模拟,并进行了模型试验验证.重点对比研究了竖井扩散段采用椭圆曲线与渐扩锥管两种形式在抽水工况出流时的流动特性.计算结果显示,渐扩锥管的配水均匀性和稳定性均好于椭圆曲线扩散管的.对比分析了弯道后渐扩锥管扩散角分别为4.3°,5°和7°时的配水均匀性,计算结果显示竖井式进/出水口应尽可能控制扩散段的扩散角,防止出现偏流;在弯管段后的扩散段的扩散角宜小于4.5°.采用物理模型对推荐体型进行了验证,模型试验显示按照推荐体型设计的进/出水口配水均匀,双机抽水工况下总水头损失系数为0.48;双机发电工况下,总水头损失系数为0.33.
In order to improve the flow patterns in the vertical well entry / draft tube of pumped storage power stations,both numerical simulations and model experiment investigation were carried out to study the hydrodynamic characteristics.And a 3D RNG k-ε turbulence model was adopted in the numerical efforts.The flow characteristics of two kinds of diffusers,one is ellipse curve and the other one is cone expansion,were mainly compared under pump conditions.The results showed that the flow patterns in the tube with a cone-shaped diffuser were better than that with an ellipse one.The flow rate allocation ratios in the tubes with a cone diffuser of 4.3°,5°,and 7° diffusion angles were simulated and analyzed.The results indicated that the diffusion angle of the cone diffuser installed behind an elbow pipe should be less than 4.5°.The hydraulic model experiments were conducted for the recommended vertical well entry / draft tube.The experimental results showed that there were uniform flow patterns in the models.The loss coefficient of the total head was 0.48 when two units were operated under pump condition while it was 0.33 under turbine condition.
出处
《排灌机械工程学报》
EI
北大核心
2012年第5期548-552,共5页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(50879075)
关键词
抽水蓄能电站
竖井式进/出水口
水力特性
扩散角
数值模拟
pumped storage plant
vertical pipe intake
hydraulic characteristics
spread angle
numerical simulation
