Analysis And Test Research On The Characteristics Of Turbine Generator Journal Bearing

Journal bearing is the important part of rotating machinery. It influences the safe and reliable operation of unit largely. It is important for people to research bearing performance.Model to solve journal bearing Reynolds equation using the finite difference method was set up. Bearing performance calculation software using MATLAB was developed. Oil pressure distribution in bearing gap and change of bearing load with rotating speed, eccentricity and ratio between length and diameter was analyzed.Three dimensional CFD model to analyze bearing performance was set up. Oil pressure field, temperature field and velocity field in bearing was calculated. Influence of rotating speed on oil field was researched. Difference between the calculated results of the three dimensional Navier-Stokes equation and the Reynolds equation was compared. It is found that the difference increases with the increase of rotating speed and eccentricity. The difference is more distinct in the case of high rotating speed and large eccentricity.Bearing test rig was designed. It includes mechanical system, bearing system, oil system, load system and test system. Bearing performance measurement system using Labview was also developed. Oil pressure and temperature distribution in bearing gap was tested and observed. The three dimensional calculation results and the test results were compared and verified.Load is the important factor influencing bearing performance and bearing elevation is the important factor influencing bearing load. Tests of bearing elevation change during run up and run down process were done on a 330MW and 1000MW turbine generator unit for analyzing fault reason of high bearing temperature. Test results show that the relative elevation change between two bearings during run up and run down process is high. It changes load distribution among unit bearings. Elevation of bearing 4 and bearing 8 is high in working state which is the main reason of high bearing temperature. Elevation of bearing 4 and bearing 8 is lowered in overhaul. The high bearing temperature fault was solved successfully.