气悬浮离心制冷压缩机轴承承载特性分析

Analysis of Bearing Load Characteristics of Air-suspended Centrifugal Refrigeration Compressor

离心制冷压缩机是离心式冷水机组的核心设备,对气悬浮离心制冷压缩机轴承承载特性进行分析具有重要意义。在制冷剂流态分析的基础上,采用计算流体动力学软件,计算得到气悬浮离心制冷压缩机轴承的气膜压力分布及承载力。通过分析确认:工质为R134a制冷剂时,气悬浮离心制冷压缩机轴承内部的流态比空气环境复杂,属于层流、湍流共存的混合流态;轴承气膜压力分布规律在R134a制冷剂环境中与在空气环境中基本相同,但是最大气膜压力在R134a制冷剂环境中大于在空气环境中,最小气膜压力在R134a制冷剂环境中小于在空气环境中;在R134a制冷剂环境中,随着偏心率增大,主轴转速提高,轴承宽度增大,最大气膜压力和最小气膜压力都会增大,轴承的承载能力提高。

The centrifugal refrigeration compressor is the core equipment of the centrifugal chiller,and it is of great significance to analyze the load characteristics of the bearing of the air-suspended centrifugal refrigeration compressor.On the basis of refrigerant flow pattern analysis,computational fluid dynamics software was used to calculate the air film pressure distribution and bearing capacity of the bearing of the air-suspended centrifugal refrigeration compressor.It is confirmed though analyses that when the working medium is R134 a refrigerant,the flow pattern inside the bearing of the air-suspended centrifugal refrigeration compressor is more complicated than the air environment,and it is a mixed flow pattern in which laminar flows and turbulent flows coexist.The bearing air film pressure law in the R134 a refrigerant environment is basically the same as that in the air environment,but the maximum air film pressure in the R134 a refrigerant environment is greater than that in the air environment,and the minimum air film pressure in the R134 a refrigerant environment is less than that in the air environment.In the R134 a refrigerant environment,as the eccentricity increases,the rotation speed increases,the width of the bearing increases,the maximum air film pressure and the minimum air film pressure increase,and the loading capacity of the bearing increases.