三峡工程水轮机的浑水特性和磨损特征

The Silt-Laden Flow Characteristics and Silt Abrasion Features of Hydraulic Turbine for Three Gorges Power Station

针对三峡工程水轮机的运行特点，采用长江天然泥沙进行了三峡水轮机模型浑水试验研究，其目的是了解水流挟沙对三峡水轮机性能的影响、水轮机转轮内泥沙磨损部位及相对强度等，为真机防护及运行提供依据．试验在中国水利水电科学研究院水力机电研究所高精度水力机械通用模型浑水试验台上进行．试验内容包括清浑水能量试验、清浑水临界空化性能与初生空化性能试验、清浑水水压脉动试验和泥沙磨损试验．结果表明，在三峡水电站过机泥沙条件下，水流挟沙对水轮机效率、运行工况及水压脉动的影响很小，而对初生空化影响比较大，即随着含沙量的增大，初生空化系数有增大的趋势．此外，为减轻磨损，汛期浑水工况下水轮机应尽量避免过大开度或超负荷运行，转轮抗磨防护重点部位为叶片出水边和下环内侧面．

According to the operating characteristics of Three Gorges Power Station, the model hydrotur-bine experiments are carried out with Yangtze River sand for knowing the influence on its characteristics whenwater carring sand, the abrasion positions of runner and the abrasion intensity. The references for theoperation and protection of hydraulic turbine can be obtained. The model experiments are carried out in IWHR.As a result, in the silt condition of Three Gorges Power Station, it is very little of influence on efficiency, pres-sure fluctuation and operation mode, but obvious on incipient cavitation. The more the silt content, the largeris the incipient cavitation coefficient. Morever, the turbines should not operate at large opening and overload inflood period. The main protected positions of runner are the blade outlet and the inside surface of band.