Influence of Radial Installation Deviation on Hydraulic Thrust Characteristics of a 1000 MW Francis Turbine

Abstract

In this paper, a 1000 MW Francis turbine was used to study the influences of uneven clearance distribution caused by various radial installation deviations on the hydraulic thrust of a runner under the rated operating condition with steady-state CFD analysis. Then, the influences of radial installation deviation on the pressure pulsations of the runner and the fluid domains most affected by the deviation were investigated via unsteady CFD calculation. The results show that the radial hydraulic force on the chambers increased linearly with the increase in the radial installation deviation. Additionally, the high-pressure zone was not located in the same position as the radial deviation. With increasing values of the radial installation deviation, the high-pressure zone rotated along the opposite direction of the rotating direction of the runner. This study also found that the flow in the upper crown chamber was most affected by radial installation deviation and that the percentage of high frequencies of the pressure pulsations increased with the flow in the clearances.

Keywords

• 1000 MW Francis turbine
• radial installation deviation
• installation deviation control
• pressure pulsation
• hydraulic thrust