Simulation of large thrust-bearing performance at transient states, warm and cold start-up

Abstract

The start-up of a large hydrodynamic thrust bearing of a vertical hydrogenerator is one of the most critical situations during the lifetime of a bearing. Hydrodynamic load capacity is low due to low speed and higher thermal deformations of the pad. A new approach to the simulation of a hydrodynamic bearing is shown in this article. A combination of finite elements method and computational fluid dynamics is used to perform the transient simulation of the bearing start-up. A bidirectional bearing of a pump-storage power plant is investigated. To show the potential advantages of the new method, a comparison of the warm and cold start procedure is presented. The thermal crowning of the bearing pad, oil film gap and other parameters of both cases are compared in this article.