云南某水电站水库泥沙淤积数值模拟研究

Numerical modeling of sediment deposition of reservoir in a hydropower station in Yunnan Province

水库泥沙淤积引起库区水位抬高,侵占调节库容,造成库容损失,且有害粒径对水轮机造成磨损,从而引起水轮机运行效率下降、出力和年发电量减小、检修间隔缩短和费用增大。以云南某水电站水库为例,利用非恒定一维模型对库区泥沙淤积形态、泥沙冲淤、过机含沙量等变化进行数值模拟。结果表明:水库泥沙淤积形态为三角洲淤积,泥沙淤积对调节库容的影响较大;通过水轮机水流的含沙量较小、粒径较细,泥沙对水轮机的影响较小;泥沙淤积数值模拟与实测资料相符,因此采用非恒定一维模型进行泥沙淤积数值模拟是可行的,可有效地解决云南地区泥沙淤积数值模拟的难题。

Siltation caused the reservoir water level elevation,which occupied the regulation storage capacity and resulted in the loss of the reservoir storage capacity. Because of the abrasion of the hydroturbine caused by the harmful particles,the operation efficiency of the hydroturbine dropped,the output and annual power generation decreased,and the maintenance interval was shortened while the cost increased.Taking a hydropower station in Yunnan Province as an example,the unsteady one-dimensional model is used to simulate the sediment pattern,sediment erosion and deposition,and sediment concentration in the reservoir area. The results show that the reservoir sedimentation patterns is delta sedimentation,and the sediment deposition has great effect on regulation storage capacity. The sediment through the hydroturbine has small amount of sand and fine sediment gradation,and the sediment also has small impact on the hydroturbine. The numerical simulation of sedimentation is consistent with the measured data,so it is feasible to use the unsteady one-dimensional model for numerical simulation of the sediment deposition and effectively solve the problem of numerical simulation of the sediment deposition in Yunnan Province.