Stability Evaluation And Experimental Research On High Speed Turbine Dynamic Shaft System

Energy is the important guarantee of national economic and social development, and the energy security also ensure the sustainable supply of national energy and healthy development of social economic. Distributed energy system can be easily located near the client in the form of small scale and small capacity,etc., which can make up for the shortcomings of the existing centralized power supply to a great extent,and make the complementarities with bulk power systems. In the distributed energy system, there are quite a few rotating machineries appearing as dynamics armaments, and developing to be more high-speed, miniaturization and integration. Especially in the past decade, the integrated design of air lubrication technology and high-speed flexible rotor progresses, making the rapid development and application of air bearing, including the application of miniature gas turbine, intern-al combustion engine and expansion chiller,etc. power machinery. And the stability problem of the high speed rotor supported by the gas bearing in miniature power machinery draws more and more attention.In the high speed rotating machineries presented by miniature gas turbine technology,expansion chiller and turbo-generator, the study on the stability of high speed turbine shaft is of great significance, and the assessment of which is the most important. The assessment techniques and methods are directly related to the stability judgment of high speed shaft, and then affect the operation of subseq-uent processing on the equipments, finally concern the safety and stability of the operation of high speed rotating machineries.Aiming at the stability assessment techniques and methods of high speed turbine power shaft, this paper carried out the following studies:1. Through the discourse with four analytic model of shafting nonlinear vibration:Lund model, Muszynska model, Yuri model, Coupling vibration model and the discrimination criterion, contrastive analyzed their own characteristics and application condition. Explained the characteristics of the shaft coupling vibration model and engineering stability criterion and proposed the shafting nonlinear vibration graph analysis method.2. Based on the requirements of top-level design of experimental platform, the construction of the experimental platform for the high-speed turbine generator combined with the function and performance were completed, mainly including the power supply and gas piping system, on-line monitoring system and remote control and the high speed turbine generators with compressor-turbine-generator coaxial structure. Type selection and installation design of sensors were completed and position and dimensions of key groove were analyzed, the dynamic balance was completed applying the DASP software.3. Aiming at the exposed problems of DASP vibration acquisition and analysis software during the course of the experiment, the editing phase signal is analyzed;slow rolling compensation vector optimization form the Bode diagram and polar plots, orbits were analyzed, so that the vibration of the test signal can be "measured," "true," "analyzed accurately";the affect on the stability of the bearing rotor system for bearing gas supply pressure are analyzed to understand the fundamental vibration characteristics of high speed turbine generators.4. Aiming at the various vibration phenomenon caused by rubbing, including automatic deceleration, axial and radial rub, periodic rub and speed rise, the rationality and universality of stability assessment methods were analyzed. The vibration feature graphs of typical faults were given. The stability of bearing-rotor system during the course of the experiment was evaluated according to the engineering stability criterion and inference. Based on the coupling of FM, through changing structure of the equipment, adjusting bearing gas pressure, adjusting the driver gas flow, the purpose of controlling "boundary of chaos" and improving the stability of shaft system was attained.The effectiveness of the coupling frequency modulation technology was verified. On this basis, the experiment of cooling, heating and power system of high speed turbine generators was made, and vibration of equipment, characteristics of heat and power generation were analyzed, the result will provided the basic data for the following functional performance test of high speed turbine generators.