汛期调度运行方式对径流式水电站防沙排沙条件的影响——以桐子林水电站为例

Influence of Operation Mode in Flood Season on Sandprevention and Sediment Ejection Conditions of Run-of-river Hydropower Station:A Case Study of Tongzilin Hydropower Station

坝前防沙条件、排沙效率是影响径流式水电站使用寿命及厂房发电安全的重要因素。为研究径流式水电站在汛期采取不同调度运行方式对电站汛期排沙、防沙效果的影响,通过非工程措施改善坝前排沙、防沙条件,采用FLOW-3D数值模拟软件建立三维水沙数值模型,模拟了桐子林水电站在不同坝前来流情况下,采取不同的调度运行方案时,电站取水前池的流速、流态和泥沙输移情况。结果表明:不同的调度方案可改变坝前水动力轴线、推移质输移带走向,因此在满足电站安全运行的前提下,采取合理的调度运行方式可使电站防沙效果取得最佳;汛期电站排沙以集中开启泄洪闸排沙为宜;坝前来流较大时电站需开启冲沙底孔,关闭发电机组以保证生产安全。

Sediment prevention and ejection efficiency in front of the dam plays significant role in the service life and safe production of run-of-river hydropower station.In order to study the influence of different operation modes of run-of-river hydropower station on sediment prevention and ejection efficiency in flood season,adopt non-engineering measures to improve sediment prevention and ejection efficiency,a three-dimensional flow-sediment numerical model was established through FLOW-3D numerical simulation software.The flow velocity,flow pattern and sediment transport in water intake front pool of Tongzilin Hydropower Station under different inflow conditions and operation modes were simulated.The results show that different operation modes do change the hydrodynamic axis and bedload transport direction in simulation area.Within the premise of safe operation of the hydropower station,a reasonable operation mode may help to achieve the best sediment prevention and ejection efficiency.In flood season,it is appropriate for hydropower station to centrally open sluice to discharge sediment.When the incoming flow of the dam is much greater,the power station needs to openthe sand flushing bottom hole and close the generator set to ensure production safety.