Study On Fault Mechanism Of Centrifugal Compressor Thrust Bearing

Centrifugal compressors are widely used in petroleum, petrochemical, water utilities, chemical and metallurgical process industry, the safe operation of the centrifugal compressor is essential to stability and safety of enterprises. Centrifugal compressor failure was widespread attention and studied by us, the thrust bearing failure is important factor to limit long-running of centrifugal compressor. The typical thrust bearing fault is due to excessive axial load, produced larger axial displacement, oil film rupture occurred, the bearing pad burnt, thrust bearing damaged, compressor was forced to stop. Based on these reasons, in this paper, FSI software CFX-ANSYS was used to study failure mechanism of centrifugal compressor thrust bearing. The main researches were performance parameters of thrust bearing, such as:oil film pressure, oil film temperature and the relationship between bearing capacity and axial displacement.Firstly, the mathematical model of centrifugal compressor thrust bearing was established, including the lubricant film Reynolds equation, viscosity--temperature equation, energy equation and film thickness equation, and had understood the lubricating mechanism of thrust bearing. The calculation method of the mathematical model was listed, finally, the fluid-structure interaction software CFX-ANSYS numerical simulation method was selected to analyze it.Secondly, the performance parameters of centrifugal compressor thrust bearing were calculated using fluid-structure interaction method. Calculations were carried out with different speed and different oil film thickness. Calculations results included oil film pressure, oil film temperature, thrust bearing pad deformation and the relationship between bearing capacity and axial displacement.Thirdly, the thrust bearing experiments were carried out using laboratory existing turbine compressor. During the experiments, researched the test mechanism, then built the centrifugal compressor thrust bearing test rig, detailed experiment procedures. Through those experiments, the relationships with different load conditions between bearing axial load and axial displacement of thrust bearing were studied.Finally, the multi-functional new-type centrifugal compressor was designed based on the original test rig. In the new design of the test rig, introduced new magnetic bearing, improved fuel injection chamber and designed the compressor impeller.