Influence Analysis Of Shaft Elevation Variation On Bearing Load And Design Of Elevation Measurement System

Shaft elevation is a critical factor that affects the safe operation of the turbine generator.With the development of modem units to large capacity and high parameter,the more complex of the Shaft elevation change,the more likely to significant vibration fault and safety of the units.How to determine the reasonable bearing elevation and load distribution of the research has attracted much attention.Shafting elevation measurement and analysis will be an effective method to solve the vibration fault of turbine units.In this paper,detailed analysis were done for the 600 MW turbine generator.The rotor model was based on the lumped parameter method.Using transfer matrix method to calculate the elevation curve and the load distribution of each bearing.The paper discusses factors which influence bearing load distribution.the calculation results of bearing load and sensitivity for unit are analyzed and summarized.it is shows that a bearing elevation changes,any two adjacent bearings load changes in the opposite direction;a bearing elevation change has the greatest influence on its own and the other side of the coupling bearing,the changes of these two bearing load have the same size but opposite.These conclusions can be useful for the field engineering practice.In the research of the shafting elevation measurement system based on the vessel.The design of the system is studied from the aspects of hardware selection,software design and so on.First of all,the hardware device was studied,and the high precision eddy current sensor,the front-end device and elevation data acquisition module were used to achieve the function of data acquisition and signal processing.Then,the system software was designed with Visual C++,adopting modular structure.The display interface of the software is designed as the menu.The shafting elevation measurement system applied to the actual case,bearing elevation on a supercritical wet 660 MW unit and a domestic air cooling 600 MW turbine are measured and the measurement results were analyzed and summarized.The reliability of the system is verified.At last,this paper introduces CEEMD method,analyzes and compares the differences of the conventional EMD and CEEMD signal analysis methods,an improved noise reduction method based on threshold value was put forward and combining with the case of a certain power plant,the admission of failure is analyzed,diagnosed and treated.