超长引水明渠水电站的过渡过程和运行调度

Transient flow and scheduling strategy of long diversion open channel in a hydropower station

过渡过程计算分析对水电站安全运行极为重要。基于一维明渠和有压管道的非恒定流基本理论,针对某具有超长引水明渠的水电站,构建了"长引水明渠+压力前池+压力管道+机组"的过渡过程数学模型。根据边界条件,分别利用特征线法计算有压管道的瞬变过程和Preissmann隐式差分法计算明渠的瞬变过程。重点分析了本电站在机组甩负荷工况和增负荷工况下,引水明渠和压力前池中水位和流量的变化过程。并根据明渠浅水波传播慢的特点,针对电站增负荷工况,提出了该电站合理的运行调度方式,既保证了引水明渠及前池的最低水位满足安全运行要求,又保证了电站运行时一定的经济效益,可对类似的工程运行提供参考。

The calculation and analysis of transient process is important to the security of hydropower station.Based on the one-dimensional unsteady flow theory,a numerical model of ＂ong diversion open channel ＋ pressure forebay ＋ pressure conduit＋ units＂for the system was established for a special hydropower station with long diversion open channel.According to boundary conditions,it calculated the transient flow of pressure pipe using the characteristic method and calculated the transient flow of open channel using Preissmann implicit difference method.It analyzed the change of water level and discharge in channel and forebay in different conditions.It decided the reasonable approach to increasing load due to the low velocity of wave spreading.It ensured the lowest level of open channel and forebay and economic benefits.This gives significant reference to analogous engineering.