Full-scale Measurements of a 9.3 MW Hydropower Unit in Porjus : A Prestudy of the Instrumentation of the Runner and the Guide Bearings

In this diploma thesis two partial studies of the instrumentation of a hydropower unit are conducted. These are carried out within the scope of the JUSPOWER-project. The first part of the thesis deals with the instrumentation of the runner. The incorporation of sensors in a Kaplan runner blade is tested in a experimental set-up on a laboratory scale without dismantling the runner. A further development of the design is suggested that enables damaged sensors to be replaced. The sensors are calibrated with a system destined to be used on site. The results show that the sensors function properly in the test set-up. Further calibration will though be needed during the installation on the runner blade and under operational conditions. The suction cup of the calibration system may have to be modified depending on the shape of the runner blade. The second part is a comparison study concerned with the choice of sensors for radial load measurements at the guide bearings. To measure the load on the bearing segments, the dowel peg on the bearing segment would either be replaced by a load cell or modified so strain gages could be bonded onto the peg itself. The performance of the sensors is evaluated in a loading machine with respect to linearity, hysteresis and sensitivity. Furthermore, the stiffness of the load cell is experimentally determined in a load machine. The results show that the strain gages bonded on the modified dowel peg do not have a reliable output signal. However, the installation of the tested load cell would alter the stiffness of the dowel peg. The load cell had a stiffness that was almost 50 % lower than the dowel peg.