Author(s): H. Novik; O. Jorstad; L. Lia
Linked Author(s):
Keywords: Trash racks; Hydro power intakes; Back flushing
Abstract: Back flushing of trash racks at intakes for hydro power plants is a hydraulic based alternative to manual or mechanical removal of debris causing loss of total pressure and reduction of clean energy production. Higher frequency of floods in a river can increase already existing problems with trash and floating debris. Characteristics of a flow associated with effective back flushing are investigated in a laboratory flume provided with a section of a full scale, reversible, trash rack and in a prototype, Eidsdal Power Plant. Key parameters studied are the relative flushing velocity, the flushing duration and the initial head loss over the trash rack before back flushing. Clogged debris is efficiently removed by a back flushing process and the efficiency tends to increase with decreasing initial head loss. Most of the debris is loosened with the first minute of back flushing.
Year: 2011