Sediment deposition can cause a reduction in reservoir capacity and hydro-mechanical abrasion of pumped-storage power stations (PSPSs). To increase the operating efficiency and service life of PSPSs, sediment deposition in the process of reservoir water transfer needs to be addressed. Combined with hydrodynamics, reservoir sedimentation theory and a numerical model, a two-dimensional sediment model of the lower reservoir of Tianchi PSPS was established. Considering the characteristics of the upper and lower reservoirs of this PSPS, water and sediment exchange between the reservoirs was realised by setting source and sink terms. The process and distribution of sediment deposition were analysed over 50 years. Sediment deposition in the lower reservoir of the PSPS was found to be 0.5–1.8 km in front of the dam and triangular. The main stream of sediment-carrying flow could be moved from the right-hand channel to the sediment discharge tunnel and spillway by setting up a sediment discharge trench. The average sedimentation thickness of the reservoir during 10 years of operation was about 0.8 m with a sediment intercept weir (SIW) established, while it was more than 4.2 m in the main stream area outside the SIW. For operation of 50 years, these values were 3 m and 10 m, respectively. The SIW effectively reduced deposition near the inlet (outlet) of the PSPS, the amount of sediment passing the machine and deposition to the dam front. The results provide a reference for simulations and preventive measures of sediment deposition in PSPSs.

中文翻译：

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数学模型在抽水蓄能水库淤积研究中的应用

沉积物沉积会导致抽水蓄能电站 (PSPS) 的水库容量减少和水力机械磨损。为了提高PSPS的运行效率和使用寿命，需要解决水库输水过程中的沉积问题。结合水动力学、水库淤积理论和数值模型，建立了天池PSPS下水库二维淤积模型。考虑到该PSPS上、下水库的特点，通过设置源汇项实现水库间的水沙交换。分析了50多年来沉积物沉积的过程和分布。发现 PSPS 下水库泥沙沉积在坝前 0.5-1.8 公里处，呈三角形。通过设置排沙沟，可以将携带泥沙的主要水流从右侧通道转移到排沙隧道和溢洪道。水库运行10年平均泥沙厚度约0.8 m，建有拦沙堰（SIW），而在SIW以外的干流区则超过4.2 m。对于 50 年的运行，这些值分别为 3 m 和 10 m。SIW 有效地减少了 PSPS 入口（出口）附近的沉积物、通过机器的沉积物量和沉积到坝前部的沉积物。研究结果可为PSPS泥沙淤积模拟及防治措施提供参考。