USE OF TURBINES WITH SPIRAL BLADES

Abstract

In recent years, small hydropower plants have been widely using screw turbines are widely used in small hydropower plants. Toimprove their design, a turbine with spiral blades was proposed.The basis of this solution was to improve a screw turbine, in which, through structural changes and the addition of new components, the efficiency is increased by creating a gradual diversion from the flow center with the concentration of the driving forces of the flow closer to the turbine casing (larger diameter), and their maximum exchange of mechanical energy with the spiral blade by creating a vacuum at the outlet.The task was also set to reduce the size of the structure compared to the already known turbines of similar power. Anadditional task was also set to reduce kinetic energy losses (accumulation and conservation of kinetic energy – the flywheeleffect).The tasks are solved in the proposed solution of a turbine with blades arranged concentrically and spirally along the axis of rotation of the turbine and fixedly connecting the casing to the shaft located along the axis of rotation of the turbine. The blade is designed to maximize the overlap of the flow path, with the blade to casing angle gradually decreasing from the inlet to the outlet. The turbine is constructed with a gradual decrease in the area of the flow channels from the inlet to the outlet of the casing. The proposed solution of a turbine with spiral blades provides for the placement of a hollow cylindrical turbine casing on the shaft, which is fixedly connected to the spiral blade.The technical result is achieved by forming a channel area inside the turbine with a gradual decrease in the flow area to the outlet, which allows increasing the power of the proposed turbine solution using an additional pressure drop in the hydraulic turbine, physically enhancing the hydrodynamic interaction, which occurs both by increasing the amount and speed of the fluid passing through the hydraulic turbine and by increasing the static pressure drop both in and behind the hydraulic turbine.