Dynamic Optimization Design Of A Big Turbo-Generator Rotor-Bearing System

Based on the prestrss method to study the critical speeds of a big turbo-generator rotor system and analyse the unbalance-response about the rotor system in the dissertation.It is analysed that the relation of magnetic tensile force and the lateral vibration , ther mal expansion and the lateral vibration on the basis of the enginee -ring problem.The optimization design of a big turbo-generator rotor-bearing system is studied profound -ly and broadly in this dissertation.On the study of rotor dynamcs problem,the caculating method on the critical speeds is very important.It is necessary for the caculating method to discuss the rotor dynamics characteristics or to design a rotor system. According to the inertia property, It is added for the inertia force to the rotor system to form the prestrss solving method on the rotor dynamics in this dissertation.The prestess model is nearer the rotor working state.Its caculating process is simperer and the solution is more accurate.It is successful on Ansys5.4 platform to use prestress method to solve the problem .It is shown that other big software can be made for this kind of capulation. The relation of the magnetic tensile force or thermal expansion of the big turbogenerator rotor system and the lateral vibration are paid more and more attention on its revolving.It is related to the rotor-system dependent property for long period work.According to the magnetic tensile force or thermal expansion mechanical modelof the rotor-system,it is got the negative rigid matrix and put into whole rigid matrix,and got the influence of the magnetic tensile force or thermal expansion of the rotor-system to lateral vibration. The gap is filled in the field. It can be provided to some engineering use.On the basis of prestress method to solve rotor critical speeds,it is used for harmonic analysis to study the rotor system nonbalance response on a turbo-generator rotor-system. It is led for the rotor-system displacement to frequencies response curve and rotor-system stress-strain state at a frequencies point.By the analysis method,it has been changed for the rotor-system model to be analysed. Specialy,it is more simple and accurate that the impel force frequencies is not equal to the frequencies of the rotor revolving.lt is a new method of the non-balance response of the rotor system to be analyse.With all these result that to be analysed,it is maded the optimization desigen for a big turbo-generator rotor-system.Some of them is the design of the multi-objectives and multi-constraints rotor-system natural frequencies; the displacement response of the multi-objective and multi-constraints rotor-system.The optimization desigen method is studied on the rotor system,and to use trust region method to make the optimization desigen and the program made.On the basis of the sensitivity analysis of rotor system,it is made the optimization desigen of a big turbo-generator rotor system to the basis rigid,the axis diameter,the disc diameter,the span and so on.lt is studied for the relation of the mutil-span and the single-span rotor.In the end,it is studied rotor system mode synthesis,and made the optimization desigen.