SYSTEMATIC RESEARCH ON FLUIDIC IMPROVEMENTS OF DESILTING CHAMBERS OF HYDRO POWER PLANTS

摘要

Downstream of iver intakes of water power plants desilting chambers (Fig. 1, left) are built in order to separate undesired uspended solid particles from the water interacting with the runner blades of the turbines. The sedimentation effect of any desilting chamber strongly depends on the three dimensional characteristics of the sand laden water flow in the sand traps. Hence, the geometry of the chamber and its approaching channel as well as the shape of the calming racks at the inlet are found as to be of high importance for the settling efficiency over the whole range of water discharges. A simplified i.e. two-dimensional view of the hydrodynamic problem normally fails and does not fulfill the high demands on low costs of operation and maintenance. Therefore, the focus of the presented research project is put on the visualization and analysis of the flow characteristics in representative Swiss desilting facilities. As a first step a field campaign was performed. Acoustic Doppler Velocimeters (ADV) were used to measure the fluctuating, three dimensional velocity components v_x, v_y, and v_z of three different desilting chambers. Now the measured data is systematically evaluated and visualized.