Study On Multi-Field Coupling Dynamics Of Centrifugal Compressor Thrust Bearing

Centrifugal compressor is widely used in process industry such as petrochemical, metallurgy. functioning as the heart of human body. And, its failure will cause huge economic losses. For many years, axial displacement fault of centrifugal compression has always been a big obstacle to a reliable operation. And, because of the load applied on thrust bearing is difficult to monitor, so the reason that cause the failure can not be diagnosed accurately. In this paper, the mechanical model which can be solved to get the oil film stiffness that can be used to diagnose the axial displacement has been modeled. And the study of the key technologies has been done. The main work and contributions are as follows:Firstly, the introduction of the relevant theory of Fluid mechanics, Heat transfer theory and Elastic mechanics are given, and the relevant math’s model, for example, Sump Temperature Model, Groove Mixing Model, are also given. All these theory are contributed to the Fluid-Solid-Heat Coupled Math’s Model of thrust bearing, which should be solved to study the performance of thrust bearingBy using THRUST, the simulation is done. The oil film thickness and the maximum temperature curves, which are the function of rotation speed, axial force and oil temperature are gotten, as well as the distribution of temperature, deformation of pad and thickness, temperature, pressure of oil film.Secondly, Thrust bearing test device was constructed. Through the test bench, the study of the mechanics performance of thrust bearing can be done under different rotating speed, different axial force and different oil temperatureThirdly, through the experiment, the oil film thickness and the maximum temperature curves, which are the function of rotation speed, axial force and oil temperature are gotten. And analysis of these curves are also done. Finally, Oil film thickness and the maximum temperature of pad as a function of load and rotation speed are compared for both theoretical and experimental investigations. Fairly good agreement has been found. During the experiment, a problem of the test rig is found. In order to solve the problem, Opinions for improving the test rig are put forward.Through the study of this paper, the result can provide key technology to the fault diagnosis model based on thrust bearing oil film stiffness, and lay a good foundation for axial displacement fault on-line accurate diagnosis.