摘要
通过二维数学模型模拟水电站水库泥沙淤积情况,模拟河段起于大坝上游约600 m,止于大坝下游约400 m.计算断面在1∶2000地形图上剖分20个库区大断面,断面平均间距500 m,并通过模型试验论证数学模型模拟水库泥沙淤积变化可行性.结果表明:水库泥沙淤积形态为三角洲淤积形态,水库运行历时1 a,三角洲洲头不断地向下游前进,最终到达坝前,坝前泥沙淤积高程达1347 m,而水库泥沙淤积则向库尾高边滩发展,“翘尾巴”现象明显.水库运行1 a后,排沙比均稳定在90%以上,水库冲淤达到平衡后,采用“蓄清排浑”的运行调度方式冲沙,在泄洪冲沙底孔前形成冲刷漏斗,漏斗为三维形态,漏斗顺水流方向坡降约为1∶5.0~1∶7.0,侧向边坡约为1∶3.5~1∶4.5.取水口基本在冲刷漏斗范围内,能保持取水“门前清”.泥沙淤积的数学模型与模型试验成果基本吻合,数学模型模拟水库泥沙淤积变化可行.
The sedimentation of a hydropower station reservoir was simulated through a two-dimensional mathematical model.The simulated river reach started from about 600 m upstream the dam and terminated at about 400 m downstream.The calculation sections were 20 large sections with an average interval of 500 m in the reservoir divided by using a 1∶2000 topographic map.Additionally,the feasibility of simulating changes of sedimentation in the reservoir by the mathematical model was validated through the model test.The results show that the reservoir sedimentation is in delta sedimentation pattern.When the reservoir is operated for 1 year,the delta head keeps moving downstream,and finally reaches front of the dam with an elevation up to 1347 m.While the sedimentation in the reservoir develops to the high beach at the tail of the reservoir and the″tail up″phenomenon is obvious.After the reservoir has been operated for 1 year,the sand discharge ratio is stable above 90%.After the reservoir reaches the balance of scouring and silting,the operation mode of″storing clean and discharging muddy″is adopted to wash the sand.A scouring funnel is formed in front of the bottom hole for flood discharge and sand flushing.The funnel has a three-dimensional shape.The gradient along the flow direction is about 1∶50-1∶70,and the side slope is about 1∶3.5-1∶4.5.The intake is basically within the scope of scouring funnel,which can keep the taken water″clean in front of the gate″.The sedimentation based on the mathematical model is basically consistent with the model test results,and it is feasible to simulate the change of reservoir sedimentation.
作者
洪振国
HONG Zhenguo(Yunnan Institute of Water and Hydropower Engineering Investigation, Design and Research, Kunming, Yunnan 650021, China)
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2020年第9期910-914,共5页
Journal of Drainage and Irrigation Machinery Engineering
关键词
水库泥沙淤积
数学模型
运行方式
过机含沙量
水电站
sedimentation of reservoir
mathematical model
operation mode
sediment content passing through the turbine
hydropower station
