Experimental investigations of mobile water-power structures for small water courses

Abstract

Results are presented for experimental investigations of three designs of mobile water-power structures for small water courses.A large part of the Russian landmass is a zone of decentralized power supply; this is associated with remoteness from unified power systems (UPS) in lightly populated regions and mountainous areas, where the laying of power grids is economically inexpedient, and is coupled with heavy losses of electric power. Small-and micro-power generation may therefore be found useful for power supply to small villages and farms, as well as extraordinary situations in the case of the failure of permanent water-retaining structures after the passage of floods [1].For small water courses, we have developed designs of mobile water-power structures based on lightweight dams formed from polymeric materials, and a portable generating set with a transverse-jet turbine, which create a head of from 1 to 4 m, cover a span of up to 50 m, and ensure a producible capacity of up to 160 kW [2, 3, 4]. As operating experience with lightweight dams that have been used for irrigation in the Kursk Oblast, a stable water supply to irrigation equipment has been provided during the irrigation season at four prepared sites on the Kurits River by the installation of a single dam. The structures in question were assembled and disassembled by a crew of workers without input from specialists.The installation of these designs makes it possible to create a temporary water-management unit as a solution to local power-supply, irrigation, water-supply, and piscicultural problems, and will ensure localization of the spread of forest fires. Mobility, transportability under complex conditions, and the possibility of repeated use are referred to as advantages of these structures.These developments have been incorporated as a component part of the theme of the scientific-research study "Development of technical solutions and procedures for the installation of a complex of lightweight components of water-development works for extreme situations, water management, and land-reclamation construction," which is being performed through Grant No. MK-2068MK- .2003.08 awarded by the president of the Russian Federation.Three designs of mobile water-power structures were selected for the investigations. The first was designed with the condition that its installation would be least labor-intensive (Fig. 1). The approach conditions to this structure do not, however, provide for optimal constriction of the water flow on entering the generating set; this lowers the utilization effectiveness of the energy [5]. In this connection, we have proposed a design with a water-retaining lining fulfilling the role of a confusor, the configuration of which follows the free surface of the jet that emerges from beneath the thin wall [6]. The lining in question is given its shape by use of flexible guys and stiffeners secured in the tailrace [7]. In that case, however, the strength properties of the membrane are not fully utilized, and its thickness should be increase...