深孔泄洪洞体型的试验对比研究

Comparison Research on Experiment of Deep Discharge Tunnel Body

高速水流的水力特性是泄水建筑物体型选择需要关注的重要问题。某水电站深孔泄洪洞由导流洞改建而成,在体型设计过程中设计了竖井旋流型和"龙抬头"型两种布置方式。经水工模型试验比较分析,发现"龙抬头"型的泄洪洞不仅体型结构简单,工程投资省,而且具有水流流态稳定,泄流能力大的特点。高速水流容易引起空化空蚀的问题可以通过优化体型和掺气减蚀措施解决。经综合比较,该水电站最终采用了"龙抬头"型泄洪洞的改建方案。

The hydraulic characteristic of high-speed flow is a key issue in selection of discharge structures.The deep discharge tunnel of a hydropower station was reconstructed from an existing diversion tunnel.In the design process,two schemes were considered：the vortex shaft discharge tunnel and the ogee discharge tunnel.Through the comparison and analysis of hydraulic model tests,the ogee discharge tunnel showed many advantages,including simple structures,investment saving,stable flow,and high discharge capacity.The cavitation erosion problems caused by the high-speed water flow can be solved using the measures of shape optimization and aeration facilities.After the comprehensive comparison of the two schemes,the ogee discharge tunnel was adopted.