大型输水渠道退水口的退水能力研究

Recession capacity of discharge outlet of large water transfer channels

选取南水北调中线工程输水干渠中的澎河和澧河退水闸,采用一维非恒定计算软件,模拟计算各种紧急情况下干渠中的非恒定流态,对其退水能力进行分析和校核。结果表明:渠段两端闸门同时紧急关闭且退水闸不启用时,渠段中的水面会发生长时间的振荡。同时关闭草墩河和澎河节制闸以及该渠段间的分水口时,在设计流量下,即使不开启退水闸,也不会引起渠道漫溢;在加大流量的情况下,澎河退水闸和澧河退水闸必须同时启用至少3 h才能有效避免漫溢事故的发生。所关闭的两个节制闸间的渠段越长,退水闸运行的时间也越长。

With the Penghe and Lihe exit sluices in the main canal of the South-to-North Water Transfer Middle Route Project as examples, one-dimensional unsteady flow calculation software was adopted for simulating unsteady flow pattern in the main canal under different emergency conditions, and their recession capacities were analyzed and chocked. The result shows that large fluctuation of water surface occurs when the gates at two ends of the canal are closed suddenly and simultaneously with the exit sluices not open. When the Caodunhe and Penghe controlling gates and the diversion gate in this section are closed simultaneously, overflow phenomenon does not occur in the canal under the design flux even ff the exit sluices are closed. However, if the flux is increased, the overflow phenomenon can be avoided only if the two gates are opened for at least about 3 hours, and the longer the distance between two closed controlling gates, the mere the operating time of the exit sluices.