Experimental study of the effects on performance of Francis turbine due to sediments in flow

Abstract

Abstract The sediments in the flow cause deterioration of components of the hydraulic machinery and influence fundamental properties such as density and viscosity of the flowing fluid. Earlier researchers have demonstrated the influence of sediment-laden flow on the performance of pumps, but such investigations have not been performed for the Francis turbine. This research focused on the effects of sediment-laden flow on the performance of a Francis turbine. Hydropower Research Centre for Himalayan Region (HRCHR) had a laboratory facility especially designed to conduct tests on Francis Turbines with sediments in the flow. The test rig was a closed-loop type and had provisions for mixing sediments with water and maintaining a uniform sediment concentration throughout the circuit. The performance of a 2 kW Francis turbine was tested at three different GV (Guide Vane) angles for different load conditions with and without sediment in the flow. The results showed that there was no change in maximum efficiency in the case of a smaller GV opening, whereas the maximum efficiency in the case of sediment water was reduced for a larger GV opening. Meanwhile, Sediment particles did not affect the head under the same discharge, whereas output power decreased slightly for sediment-laden conditions.