百万千瓦水轮发电机组推力轴承润滑油膜承载性能计算及分析

Calculation and Analysis of the Bearing Performance of Lubricating Oil Film on Thrust Bearing in 1000 MW Hydro-turbine Generator Units

良好润滑、承载性能是水轮发电机组推力轴承正常工作的基础。结合白鹤滩水电站1 000 MW立轴混流式水轮发电机组,利用流体动力润滑理论及流体力学中的雷诺方程,对推力轴承润滑油膜建立数学模型,经无量纲化处理,对推力瓦面进行网格划分并采用有限差分法对方程进行数值求解,最后结合推力瓦结构尺寸及运行参数等基本数据,计算出机组稳态工况时推力轴承油膜中的压力分布规律。为机组运行维护阶段的故障诊断分析,提供了重要的参考数据。

The good lubrication and bearing performance of thrust bearings in hydro-turbine generator units are the basis of their normal operation.Taking the 1000 MW vertical shaft mixed flow hydro-turbine generator units in Baihetan Hydropower Station as the research object,a mathematic model of the lubricating oil film on the thrust bearing is established using the fluid dynamic lubrication theory and the Reynolds Equation in fluid mechanics.After dimensionless processing,the thrust pad surface is divided into grids and the equation is numerically solved using the finite difference method.At last,the pressure distribution in the lubricating oil film on the thrust bearing under steady state working condition of the unit is calculated based on the structural dimensions of the thrust pads and the operational parameters.The results provide important reference data for the fault diagnosis and analysis of the units in the operation maintenance phase.