Comportamento dinamico de mancais de guia de hidrogeradores de grande porte / Dynamic behavior of large hydrogenerators guidebearings

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

This work is divided in two parts, one theoretical and other experimental. In the first part is presented a procedure, established from an analytical study of the Reynolds equation, to determine the oil film stiffness and damping coefficients of large hydro units guide bearings. It is applied to the upper guide bearings of the Itaipu Power Plant generating units and the resulting coefficients are compared to those achieved using a program which employs the Finite Difference Method to solve the Reynolds equation. The experimental part is based on an analysis of several failures occurred in hydrogenerators, on the results of some special tests and on the monitoring of bearings temperatures and shaft vibration of the eighteen Itaipu generating units, made on a period of five years. It shows that the mathematical models of hydrogenerators, used to preview their dynamic behavior at the design phase or as a predictive maintenance tool at the operation phase, must include the effects of the guide bearings oil film stiffness and damping forces. Finally, are analyzed the consequences of several phenomenons which occurs in those machines, such as bearing deformations, seasonal changes in bearings clearances and others, in the oil film dynamic coefficients

ASSUNTO(S)

vibração mancais vibration geradores usinas hidreletricas turbines turbinas generators bearings hydroelectric power plants

ACESSO AO ARTIGO

Documentos Relacionados