抽水蓄能电站下库长系列年泥沙淤积特性研究

为了把握长系列年水沙过程对抽水蓄能电站下库区河床调整的影响,以天池抽水蓄能电站下库为例开展了不同长系列年库区冲淤变形的数值模拟。根据下库水位周期性变化的运行特点,建立了基于MIKE的水沙数学模型,并进行了模型参数调试与验证;模拟给出了长系列年的库区淤积总量及排沙比;同时也给出了库区淤积的沿程分布与特征河段的淤积过程。成果分析表明:库区淤积发展状况与水沙系列相互响应,泥沙淤积主要呈现三角洲形态,淤积重心主要集中于拦河坝上游0.5~1.8 km范围内;不同河段的淤积特性不同,淤积物组成也不同,主要与其所处环境的水力与边界特性有关;频率洪水在长系列年水沙过程中虽然占据时间不长,但在库区河床冲淤量中有重要影响;要提高排沙效率、减小淤积,需要进一步调整改善下水库的洪水调度与电站运行。研究成果与同步物理模型试验结果基本一致,可供抽水蓄能电站水库调度运行参考。

Numerical Simulation on Long Series Sedimentation in Downstream Reservoir of a Pumped Storage Power Station

In order to understand the impact of a long series water and sediment process on the adjustment of reservoir bed,we simulated the scouring and deposition and deformation in the downstream reservoir of Tianchi pumped storage power station using MIKE based on water level fluctuation in the downstream reservoir.Through calibration of parameters and model validation,we obtained the long series total deposition amount and sediment delivery ratio of the reservoir as well as the deposition profile along stream and deposition process of characteristic reaches.Results suggest that the sedimentation of reservoir corresponds with the water and sediment process.Sedimentation mainly displays a delta shape,focusing in the range of 0.5-1.8 km upstream the dam.Affected by hydraulic and boundary condition,the deposition features and deposit compositions of different reaches vary correspondingly.Floods of certain frequency has a significant influence on deposition amount despite that flood does not occupy much of the flowsediment series.Flood dispatching and operation of power station must be adjusted and optimized to enhance sediment delivery ratio and reduce sedimentation.The research results are in agreement with those from scale model test,hence could offer technical parameters for the reservoir dispatching operation.