Design And Development Of On-Line Inspection System For Dynamic Elevation Of Turbogenerator Bearing

The rationality of the shafting load distribution influences the safe and stable operation of the turbo-generator unit.Although there are many factors which affect the load distribution of the shafting,the dynamic elevation of the bearing is one of the main reasons.During the operation of the unit,the elevation change of each bearing on different position is influenced by different factors,and the elevation change law of each bearing is not the same.Therefore,to ensure the reasonable distribution of shaft load and unit operation stability and safety,it is necessary to accurately measure the dynamic elevation change of each bearing under different running conditions in order to provide a basis for pre-adjusting the bearing static level.In this dissertation,a new technical proposal for dynamic detection of bearing elevation is proposed,and a system of dynamic elevation detection for bearings in turbo-generator unit is designed and developed based on the Lab VIEW software development platform.First of all,the advantages and disadvantages of several technology for dynamic elevation measurement are compared from the following three aspects:the adaptability of the object,accuracy of signal feature extraction,and convenience of site testing conditions.By comparison,the advantages and disadvantages of special measurement method with specific sensor mounting bracket are found,and the method has been improved in this dissertation.Based on this measurement method,a numerical conversion model between measuring signal and dynamic elevation value is established according to the working principle of eddy current displacement sensor.Secondly,following the principle of detection system design,reference to the corresponding national design specification,drawing on the classic structure of detection system,the structural design of bearing dynamic elevation detection system for turbo-generator unit is finished.The selection basis of each hardware device is put forward according to the analysis of the measurement object,the characteristic of the measurement signal and the environment of the sensor installation.The hardware system designed and optimized in this dissertation for measuring bearing dynamic elevation consist of such main components as eddy current displacement sensor,front end device,sensor mounting bracket,collector and so on.The software design and development of dynamic elevation online detection system of bearing in turbo-generator unit is carried out based on the Lab VIEW software development platform.The software system mainly includes data acquisition module,system setup module,signal processing module,data storage module,and historical data playback module.The software is capable of following function of data acquisition,real-time monitoring,data storage and data playback of bearing elevation data.Finally,the software and hardware system is integrated and the experimental system is built.The experimental verification is carried out from three aspects of accuracy,stability and error correction to verify the feasibility of the dynamic elevation detection system.The experimental results show that the system developed in this dissertation has the characteristics of precise measurements and excellent stability,and it can correct the error caused by temperature.