尼泊尔上马蒂水电站取水防沙试验

Experiment on water diversion and sediment prevention of Nepal Upper Madi Hydroelectric Station

上马蒂水电站位于尼泊尔西部马蒂河上,河道来水量悬殊,水位变化较大,常年来流量及更小流量情况下取水极其困难.马蒂河属于多沙河流,且工程河段宽浅、坡陡,加剧了河道推移质泥沙运动.为了解决不同工况下电站取水、防沙问题,试验研究中,在电站首部枢纽上游布置取水口、引水渠、锁坝等建筑物,并加高溢流堰前隔水墙的高程.同时,在沉沙池内增设整流格栅后,悬移质分组沉降率得到提高,满足水轮机过沙要求.这种"逆向引水、正面排沙"的工程布置方式为解决山区多沙河流取水防沙问题提供了一种新的途径.

Upper Madi Hydroelectric Station is located on the Madi River, in western Nepal. Discharge and the water level of the river varies widely, which resulting extremely difficult conditions for water diversion under perennial flow and a smaller flow. Madi River belongs to the sandy river, and has a broad and shallow riverbed in engineering area, which aggravating the movement of the river bedloads. To solve the problems of water diversion and sediment prevention under different test cases for hydropower station, water intake, diversion channel, lock dam and other structures are adopted in the experiment study, and the elevation of the training wall before the overflow weir has been heightened too. At the same time, an additional perforated distribution plate is adopted in desilting basin, which improves sedimentation rate of grouping suspended sediment, and meets the sand requirements of the turbine. This engineering layout named ＂reverse water diversion, positive sediment desilting＂ provides a new approach to solve the water diversion and sediment prevention problem of the mountainous sandy river.