Vibration Test Of Large Machinery And Design And Experimental Studies Of Damping Devices

The cooler covers of 600MW turbine generator show a strong vibration. To ensure the safety and reliability of the generator, it is necessary to reduce its amplitude to normal range. Based on this, the main work is as follows:Firstly, according to the tested data, analysis of vibration characteristics of the turbine generator is achieved when its speed is rising and the main reasons causing excessive vibration are found. Then, identification of physical parameters of turbine generator is finished after its modal test. Based upon, numerical simulation researches of effect of supporting stiffness and phase difference of exciting force have on its amplitude are done as well as damping effect of tuned mass dampers.Secondly, in order to reduce the vibration of turbine generator, the scaled model which has the same modality with the generator is established. Using this model, comprehensive experimental studies about the effects of particle damper on vibration of the 600MW turbine generator are carried out. In addition, the performance of vibration reduction for the single-layer or double-layer structure design and different types of particles are compared. It shows that particle damper which takes the collision, friction and momentum exchange as its damping mechanism has good damping effect, the maximum amplitude reduction is more than 60%. Under certain conditions, the damping effect of double-layer particle damper is better than that of single-layer particle damper. Different types of particle damper have different damping effect. In addition, researches on damping effect of tuned mass dampers are also done with the combination of field test and finite element method. After that, influence of the amplitude of different exciting forces have on turbine generator is compared.Lastly, modal parameters of air spring vibration-isolation foundation, steel spring vibration-isolation foundation as well as rubber vibration isolation foundation are measured. Based upon, vibration transfer ratio of these vibration-isolation foundations are compared. Then, according to modal parameters of steel spring vibration-isolation foundation, single-stage and double-stage simplified model of vibration-isolation foundation are established; and effects of vibration isolation are also compared.