向家坝水电站泥沙淤积计算

为了研究上游为两个水库共同调度的情况下水库泥沙的淤积特性,选取了金沙江干流向家坝水电站作为研究对象.采用自主开发的一维非恒定流泥沙冲淤计算数学模型对向家坝水电站水库泥沙淤积进行了计算,具体对水库库区泥沙淤积、水库河床纵剖面变化、水库库容损失、水库排沙比、库区坝前泥沙淤积厚度作了计算,进一步分析泥沙淤积形态、泥沙淤积速度、库容损失以及排沙比的变化特点,得出了以下结论:由于上游水库的调度作用,使库区来水来沙较天然大不相同,导致库区泥沙淤积呈现带状淤积为主;前期泥沙淤积速度较慢,以后逐年加快,接近平衡时,淤积速度才又减慢;库容损失逐年增加;排沙比较大,水库运行前期排沙比较大但逐年减小,以后又逐年增大至水库淤积平衡.此外,还简要介绍了向家坝、溪洛渡以及雅砻江上的二滩电站的联合运行的综合拦沙效应.

Reservoir sediment computation of Xiangjiaba hydropower plant

In order to analyze the silting features of reservoir under co-regulation of 2 upstream reservoirs, the Xiangjiaba hydropower station on main Jinsha river was chosen as the research object. One-dimensional unsteady flow sediment computation model, SUSBED-UNSTEADY, developed by authors, was applied to reservoir sediment deposition computation of Xiangjiaba hydropower plant. The concrete computation issues include sediment deposition in the reservoir, variation of reservoir river bed profile, reservoir capacity losses, sediment discharge ratio of the reservoir, sediment deposition thickness in front of the reservoir dam as well as further analysis on sediment deposition form, sediment accumulation rate, variation features of reservoir capacity losses and sediment discharge ratio. The following conclusions are obtained. Due to the regulation of upstream reservoirs, the inflow water and sediment of the reservoir are very different from those of natural condition, resulting that the sediment of the reservoir deposits mainly in belt-shape ; the early-stage sediment deposition rate is slower and gradually increases year by year and then slows down near the sediment balance; the reservoir capacity losses increase year by year; the sediment release ratio in the early operation period of the reservoir is comparably larger but gradually decreases year by year, and then increases again until sediment balance in the reservoir. The comprehensive sediment retaining effect under the co-operation of Xiangjiaba hydropower plant and Xiluodu hydropower plant on the Jingsha river and Ertan hydropower plant on Yalong river is also introduced.