Investigation of Lateral Vibrations in Turbine-generator Unit 5 of the Inga 2 Hydroelectric Power Plant

Abstract

The article presents a case study on the Investigation of lateral vibrations in the turbine-generator unit 5 of the Inga 2 hydroelectric power plant in the Democratic Republic of the Congo. Lateral vibrations were experimentally determined using twelve proximity and eddy-current probes, positioned on each measurement plane. The results were analyzed using the Dasylab and R software. Hence, it was observed that the vibration amplitudes of the upper guide bearing, lower guide bearing, and pivot/rotor exceeded acceptable or critical limit values of the international vibration standard for a rotating speed between 100-250 rpm. Th ese excesses can lead to rotor mass imbalances, the eccentricity of the rotor axis relative to the rotation axis of the shaft , and the deformation of the coupling shaft between the upper rotor shaft and the turbine rotor shaft . Subsequently, the means and the variances of the vibration amplitudes were evaluated and compared to the reference values of the international standard. Th e results of the compliance analysis revealed statistically significant differences between the measured amplitudes and the reference values. Thus, it indicates deviations from international specifications.