可倾瓦滑动轴承摩擦功率损耗特性研究

为了在降低轴承能耗的同时保证透平机械的高效安全运行,对轴承-转子系统进行了更准确的建模仿真。首先对转子和轴承间隙内的油膜厚度进行了精细建模,考虑润滑油温粘效应及轴瓦变形,结合小扰动法计算轴承转子动力学参数,开发出计算五瓦可倾瓦轴承程序(COMDYN-Bearing),并将文献数据与本文数据对比,以验证本模型在多项参数中尤其是功率损耗计算的准确性。最后以某合成氨装置工业汽轮机为例,实证研究轴承宽径比、预负荷等结构参数对功率损耗以及转子稳定性的对应关系,结果表明:随着轴承预负荷的增大,轴承功耗和最高瓦温随之降低,但转子的稳定性也随之降低;随着宽径比的增加,轴承最大瓦温降低,但功耗增加,转子稳定性降低。

Investigation of the friction power loss characteristics of a tilting pad journal bearing

In order to reduce the bearing power loss without weakening the safety margin of turbo-machinery,an accurate bearing model that can be used to calculate the power loss is an important tool.A computational program (COMDYN-Bearing) for a five-pad tilting pad journal bearing has been developed.Firstly,the bearing clearance was considered,and the temperature-viscosity effect of the lubrication oil and the pad deformation were also taken into account.A small-perturbation method was used to solving rotor-dynamic coefficients of the bearings.By comparing the calculation results with the literature data to verify the reliability of the model,especially in terms of the power loss.Furthermore,a steam turbine has been taken as an example to illustrate the effect of the bearing on the performance of a rotor.The relationship between the width ratio and preload and the bearing power loss and rotor stability has been discussed.The results indicate that the power loss,pad temperature and stability decrease with increasing preload,and that increasing the pad width decreases the pad temperature and stability,but leads to increased power losses power loss.