چكيده به لاتين
Abstract:
For many years, various human societies have considered reservoir dams as an operational storage of water resources and the production of electricity from hydropower. On the other hand, the construction of the dam structure along the river's paths has the effect of disrupting the natural balance of sediment transport. The gradual accumulation of sediments not only reduces the useful storage capacity of the reservoir, but also it causes destruction and abrasion of hydro-mechanical equipment and turbines, and even block the bottom outlet gates of the dam. This issue can be considered vital, especially in countries like Iran, which are located in arid and dry areas.
So far, various methods have been developed for sediment removal from reservoirs and increasing water storage capacities in different countries. Obviously, the selection of each method is based on the climatic conditions of the area and the capabilities of each method. Dams in Iran, despite global water scarcity crises, should be clean according to proper methods in order to maintain water resources at a lower cost and easier engineering methods.
One of the methods is the use of submerged pumps and suction mixes of sediment and water. This method is usually considered for shallow rivers and ponds but we want to adopt this method for large dam. In this research, a system based on suction with a submerged pump system is designed to collect fine sediments close to body of the dam and the inputs of the power plant from a large depth and to be transmitted by floating pipes to the margin of the dam. In this system, pumping of jet fresh water flow from top elevation and creating turbulence by the jet on sedimentary bed is simultaneously used to increase harvesting efficiency. The usage of simple and inexpensive equipment for removing fine grains near the dam body without the need for a transverse displacement for removing is one of the essential features of this method which is suitable for a depth of about 100 meters. By using turbulent flow of water jet and simultaneous suction with a submerged pump, a vortices stretch is produced to suction the sediment mixture. Overall, the discharged sediment separate from water on the margin of the dam to restores water to the reservoir.
Keywords: Reservoir dams, Sediment removal, deposition, suction and jet flow
