梯级电站变动回水区设计最低通航水位确定方法

梯级电站变动回水区受上游电站下泄流量与下游坝前水位双重影响,设计最低通航水位的确定十分复杂。传统的设计最低通航水位保证率主要对流量进行统计,指标不够全面;而且设计最低通航水位计算工况组合的选取具有一定的偶然性,实际设计过程中可操作性不强。提出入库流量与坝前水位组合保证率计算方法,该方法综合考虑了入库流量与坝前水位遭遇组合的概率。利用该方法可合理确定梯级电站变动回水区设计最低通航水位,同时结合电站调度方案,在电站可接受的调度方式下,投入最少的资金对航道进行整治,以达到最优的效果。

Determination method of design lowest navigable water level standard for fluctuating backwater area of cascade hydro-power station

The fluctuating backwater area of cascade hydropower station is affected by the discharge of upstream hydropower station and the water level in front of downstream dam,thus the determination of the designed lowest navigable water level is very complicated.Traditionally,the guaranteed rate of designed lowest navigable water level mainly carries on the statistics to the discharge,but the index is not comprehensive enough;moreover,there is certain contingency in the selection of the cases combination for the calculation of designed lowest navigable water level,and the operability is not strong in the actual design process.This paper presents a method for calculating the combined guaranteed rate of inflow volume and water level in front of the dam,which takes into account the probability of the combination of inflow volume and water level in front of the dam.By using this method,the designed lowest navigable water level in the variable backwater area of cascade hydropower stations can be reasonably determined.At the same time,combined with the dispatching scheme of the power station,the channel could be regulated with the least investment in order to achieve the optimal effect.