Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine

Abstract

Abstract:In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand, the availability of experimental field data on bearing operation is limited, for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have conducted in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data.

Assembly Error Tolerance Estimation for Large-Scale Hydrostatic Bearing Segmented Sliders under Static and Low-Speed Conditions

“…HS bearings are often combined with HD bearings to reduce wear during the start and stop phase [15], compensate for misalignment, and are frequently mounted on the tilting support of the pad [16]. The HS lubrication regime increases the thickness of the film and improves circulation and cooling [17], thus improving its performance. This is one of the main reasons why HS lubrication is used as bearings on high-precision machines.…”

A novel geometry optimization approach for multi-recess hydrostatic bearing pad operating in static and low-speed conditions using CFD simulation

“…The experiments are crucial to CFD model validation, especially in cases where exact analytical approaches cannot be used. Wasilczuk et al [33] concluded that the presence of HS pockets in hydrodynamic bearings reduces the temperature change and pressure peaks, leading to higher stability of operation. The drawback of the presence of the pocket is the larger friction losses due to the cooler oil.…”

A Novel Geometry Optimization Approach for Multi-Recess Hydrostatic Bearing Pad Operating in Static and low-Speed Conditions Using CFD Simulation

“…The experiments are crucial to CFD model validation, especially in cases where exact analytical approaches cannot be used. Wasilczuk et al [33] concluded that the presence of HS pockets in hydrodynamic bearings reduces the temperature change and pressure peaks, leading to higher reliability of the hybrid bearing, but the drawback of the presence of the pocket is the larger friction losses due to the cooler oil. Wodtke et al [34] carried out experimental validation for theoretical calculations and predictions of large hydrodynamic thrust bearings and emphasized the necessity of experimental validation of numerical simulations, which are simplified and thus do not represent the real geometry and other influential effects.…”