Abstract

MAIGUA, Carlos et al. Design of a Mechanical Vibration Monitoring System in Medium Power Hydroelectric Generators. Revista Técnica energía [online]. 2020, vol.17, n.1, pp.92-102. ISSN 2602-8492.  https://doi.org/10.37116/revistaenergia.v17.n1.2020.397.

The objective of the research was to develop a methodology aimed at monitoring and forecasting the actual condition in a medium power hydroelectric generator. The proposed procedure was based on the continuous monitoring of the energy behavior of the vibration signals, using accelerometers with output proportional to the general speed vibration level. The variable considered is the RMS value of the vibration velocity referred to the amount of fatigue stress. Through virtual instrumentation the signals were processed and converted into a numerical value, defining the upper and lower limits for each of the critical zones (A, B, C, D) according to the parameters described in the standard STN ISO 10816. Measurements and historical records were made during 3 weeks, during that evaluation period the generator operated at 80 % of its capacity, and a wave spectrum with a constant trend was displayed within the same range of values from 0.21 and 1.79 mm/s (for the axial axis) and 0.39 and 2.23 mm/s (for the radial axis), it was concluded that these do not exceed the RMS value of the range 0.71 and 2.80 mm/s. Defining that the actual state of the rotary machine is currently within the criticality limits of zone A (new or reconditioned machine), due to the fact that the generation group was subjected to maintenance work two years ago, where several elements of the equipment were repaired, in which the change of impellers and the replacement by a turbine with a greater number of blades stands out, guaranteeing at least one normal operation in this zone during the next 6 years.

Keywords : Vibration acceleration measurements; STN ISO 10816 standard; condition monitoring of rotary machines..

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