CCS水电站输水隧洞水力特性研究

Hydraulic Performance Research for Headrace Tunnel of CCS Project

厄瓜多尔CCS水电站输水隧洞连接首部枢纽沉沙池和调蓄水库,隧洞总长24.8 km,正常运行工况下输水隧洞为明流洞,在机组甩负荷关闭隧洞出口闸门时,隧洞后半段出现压力流,因此需要对输水隧洞进行全面水力特性分析,确保输水隧洞在各种工况下安全运行。分析隧洞过流能力、水面曲线、弯道水流特性以及出口闸关闭时间不同对洞内流态的影响、消力池冲刷等表明,输水隧洞正常运行工况下水流性态良好,通过出口闸门的适时调度,可将隧洞明满流过渡段控制在较小的范围内。

The headrace tunnel of CCS project connects the desilting basin of intake complex and compensating reservoir,with a total length of 24.8 km.It’s a free flow tunnel in normal operating condition and change into pressure tunnel when the outlet gate is closed at load rejection.Therefore,a comprehensive analysis of the hydraulic characteristics of the headrace tunnel is needed to ensure the safe operation under various working conditions.In this paper,flow capacity,flow profile,bend flow,flow state transition at different closing times of outlet gate and stilling pool scour were analyzed.The study shows that the flow state of the headrace tunnel is good under normal operating conditions,and when the outlet gate is closed,the transition section between free and pressure flow can be controlled in a small range through closing time adjustment of the outlet gate.