南水北调南四湖提水泵站开启时间的分析研究

Study on the start-up time of pumping station of Nansi lakes located in the South-to-North Water Diversion Project

针对南水北调南四湖上、下级湖各自调水的出、入湖口提水泵站开启时间差的计算问题,开展了调水出湖提水泵站开启的必要和充分条件、出湖提水泵站开启时间和湖内水位升高速率等相关内容的研究。其成果表明出湖提水泵站开启不允许形成出湖口泵站引水渠进口水位下降到低于相应设计控制水位的必要和充分条件是:入湖口惯性波前锋到达出湖口水位开始上升,并且存在湖内调蓄水量满足输水流量形成恒定流水面线比降的楔形水体容积,同时为工程设计提供了出湖提水泵站开启时间、湖内水位升高速率和湖水位的相关公式以及计算图表。

In view of the calculation of the start-up time difference of in-lake and out-lake pumping stations on the upper and lower lakes, this article researches on the following related contents, such as the necessary and sufficient conditions of start-up of out-lake pumping station, the relation between tiae start-up time of out-lake pumping station and rising velocity of lake water level. The study results show the necessary and sufficient conditions that the start-up of the out-lake pumping station does not cause its diversion channel import level to fall below the corresponding water level of the control and design conditions. The related conditions are as follows, the water level begins to rise when the in-lake inertial wave reaches to the lake exports; the water-storage capacity of the lake satisfies the discharge to form the wedge-shaped water cubage of constant running water surface profile gradient. Besides, this article provides the related formula and fig-tabulations of the pumping station start-up time, rising velocity of lake water level for engineering design.