Closing rules of turbines guide vane in hydropower plants with different installed capacity
WANG Qinyi1, LIU Yi1, HUANG Wei2, ZHANG Jian1, CHEN Nan1, CHEN Sheng1*
1. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 2. Sinohydro Bureau 12 Co., Ltd., Hangzhou, Zhejiang 310030, China
Abstract：One of the most efficient ways to ensure the ecological water required downstream of hydropower plants is the expansion of modest capacity eco-turbines. For the purpose of regulating and ensuring parameters in hydropower plants that require the expansion of turbines, the coordinated guide vane closing law for capacity enhancement and original turbine selection is crucial. A transition process numerical simulation model was created based on the characteristics line method to investigate the combination of the best guide vane closing laws for hydropower plants with various installed capacities of turbines. A comparative analysis was conducted on the impact of adding new ecological small units on the maintenance parameters of the power plant, and the mechanism of the influence of the capacity of the assembled units in the power plant on the volute pressure was revealed. The results indicate that the volute pressure will exceed the control requirement if the plant′s original turbine adheres to the closing rule before adding eco-turbines, therefore, the guide vane closing time should be prolonged correspondingly. The larger the installed capacity of the unit, the lower the unit speed, and the greater the volute pressure. When different installed capacity(AABB)turbines are installed in a hydropower plant, turbine A with the smaller installed capacity can adopt the guide vane closing law of the scheme(AAAA)in which the hydropower plant is equipped with the full capacity turbine, and turbine B with the larger installed capacity can refer to the guide vane closing law of the scheme(BBBB)in which the hydropower plant is equipped with the full capacity turbine. The research results can provide refe-rence for the selection of guide vane closing law of the same type hydropower stations.
