DESCRIPTION

Technical Description

The Francis turbine is part of the reaction turbines which convert the pressure energy of water into kinetic energy in the distributor and in the rotor. Francis turbines are used at medium heads and large flow rates. The turbine power is controlled by adjusting the guide vanes. In practice, Francis turbines are used in run-of-the river power plants and in storage power plants.

The Francis turbine HM 450.02 is an accessory for the HM 450C trainer. The experimental unit consists of the rotor, the distributor with adjustable guide vanes, a band brake for loading the turbine and the spiral housing with a transparent front panel. The transparent cover enables you to observe the water flow, the rotor and the guide vanes during operation. The angle of attack and the cross-section of flow are adapted to the speed and power of the turbine by adjusting the guide vanes.

The pressure at the turbine inlet is recorded with a pressure sensor. A force sensor and a speed sensor are attached to the band brake. Thus, the mechanical power output of the turbine can be determined. Speed, torque and pressure are displayed on the switch cabinet of HM 450C and processed further in the software. Water supply and flow rate measurement are provided by HM 450C.

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- determination of mechanical output
- determination of efficiency
- recording of characteristic curves
- investigation of the influence of the guide vane position on the power output
- velocity triangles