Kaplan Turbine

Kaplan turbines are characterized by an axial flow through and adjustable blades. They are used at low heads and very large flow rates. Because Kaplan turbines belong to the double regulated turbines, meaning that both the guide vanes and the blades can be adjusted, they are suitable for operation at changing operating conditions. Compared to fixed-blade propeller turbines, Kaplan turbines offer a high efficiency over a wide range of operating. In practice, Kaplan turbines are used in run-of-the river power plants. The experimental unit consists of the rotor with blades, the distributor with guide vanes, a wear-free and the housing with a transparent pipe element. The transparent cover enables you to observe the water flow, the rotor, the distributor and the guide vane and blade adjustment. The angle of the water inlet into the turbine and the cross-section of flow are adapted by adjusting the guide vanes. The adjustment of the blades allows the velocity at the rotor to be adapted. The combination of both adjustment options optimizes efficiency and keeps losses as low as possible. The pressure at the turbine inlet is recorded with a pressure sensor. Thus, the mechanical power output of the turbine can be determined. Speed, torque and pressure are displayed on the switch cabinet and processed further in the software. Water supply and flow rate measurement by base unit.

Learning Objectives

• Determination of mechanical output
• Determination of efficiency
• Recording of characteristic curves
• Investigation of the influence of the guide vane and blade position on the efficiency