白鹤滩水电站输水发电系统水工模型试验研究

Experimental Study on Water Conveyance System of Baihetan Hydropower Station

白鹤滩水电站单机容量目前居世界之首,输水发电系统规模巨大,尾水隧洞存在明满流现象,尾水调压室存在上室明流,水力学条件复杂,有必要深入研究输水系统水力学问题。采用整体模型试验方法,研究尾水隧洞出口结构布置形式的影响和输水系统整体布置的合理性。结果表明,尾水隧洞出口设置逆坡堰,可明显改善尾水隧洞明满流流态,减小尾水连接管进口负压,抬高尾水调压室最低涌浪水位,水力学条件更优。大波动工况下,输水系统各部位压力和涌浪极值满足设计要求,输水系统布置合理。研究结果可为白鹤滩工程设计提供技术支撑,也可为类似工程提供借鉴。

The single unit capacity of Baihetan Hydropower Station currently is the world's largest.The water convey-ance system is huge and the hydraulic conditions are complicated.The tailrace tunnel has free-surface-pressurized flow and the upper surge chamber has open channel flow.It is necessary to conduct further study on the hydraulic problems.In this paper,experiment method was adopted to research the influence of the tailrace tunnel outlet structure layout and the rationality of the overall layout of water conveyance system.The results show that the adversary slope weir at the outlet of tailrace tunnel can significantly improve the free-surface-pressurized flow regime,reduce the negative pressure at the inlet of tailrace connecting pipe,raise the lowest surge level of tailrace surge chamber,and have better hydraulic condi-tions.In large fluctuation operating conditions,the extreme pressure and surge water level in different parts of the water conveyance system meets the design requirements,and the layout of the whole water conveyance system is reasonable.The research results can provide technical support for Baihetan project design,and can also provide reference for similar projects.