超临界二氧化碳涡轮机主轴静压轴承承载特性分析

以超临界CO 2涡轮机主轴支承静压轴承为研究对象,基于Fluent软件建立静压轴承气膜的三维分析模型,分析了轴承结构、偏心率、气膜间隙对气膜压力、承载力和刚度的影响。结果表明:双排进气结构静压轴承的气膜压力、承载力和刚度均高于单排进气结构;偏心率对承载力有显著的影响,承载力和偏心率呈非线性正相关;在偏心率一定的条件下,平均气膜间隙较小的静压轴承承载力和刚度更高;刚度和偏心率呈现高度的非线性关系,刚度随偏心率的增大先增大后减小,偏心率为0.32时出现极值,且极值前刚度的增长梯度明显高于极值后刚度的减小梯度。

Analysis on Load Characteristic of Hydrostatic Bearings for Main Shaft of Supercritical CO2 Turbine

Taking hydrostatic bearings supporting main shaft of supercritical CO2 turbine as research objects.Based on Fluent software,a three-dimensional analysis model is established for gas film of hydrostatic bearings,and the effects of bearing structure,eccentricity,gas film clearance on gas film pressure,load capacity and stiffness are analyzed.The results show that the gas film pressure,load capacity and stiffness of hydrostatic bearings with double row intake structure are higher than that of single row intake structure.The eccentricity has a significant effect on load capacity,and the load capacity and eccentricity have a nonlinear positive correlation.Under certain conditions of eccentricity,the load capacity and stiffness of hydrostatic bearings with smaller average gas film clearance are higher.The stiffness and eccentricity show a highly nonlinear relationship.The stiffness firstly increases and then decreases with increase of eccentricity,an extreme value appears at the eccentricity of 0.32,and the increasing gradient of stiffness before extreme value is significantly higher than decreasing gradient of stiffness after extreme value.