Research On The Effect Of The Air Compressor Impeller Size On The Fatigue Life

Magnifying scale to improve the system efficiency of air separation equipment and reduce system energy consumption.But after the large-scale,air separation equipment can make the system stability and the fatigue life of key components get weak.Because our country in this respect the weak theory research and the development of the domestic large air separation equipment lags behind developed countries.This text selects the air compressor impeller in air separation system as the research object,using TCD series system reliability and stress gradient analysis,statistical analysis theory to study the parts size change on the influence law of its fatigue life,the proposed compressor impeller size not its fatigue life prediction method,the specific finished the following work.(1)Using the theory of Weibull distribution to modeling of unit piece of life,combining the theory of reliability of series formulas deduced the fatigue life of large components.Using four groups of different sizes and different defect specimen test experiment data,the fatigue life of verify the theoretical calculation results.Through the theory also validation:statistical factors is widespread in the mechanical components of different size;Component is weak link in volume or tend to infinity when its statistical factors effect will gradually table.(2)Using the Workbench to the impeller model simulation,determine the impeller stress value at risk at work,the stress concentration factor of hazard points were calculated results.Dangerous points are simulated for different size of the impeller,the different sizes is obtained under the dangerous points of stress gradient data;Using the Origin of stress gradient data fitting,the changing law of stress gradient curve with size approximate expression,and the coefficient of the size of the impeller,the impeller size and dimension coefficient relation rule.(3)Determine the coefficient of the comprehensive correction coefficient of the size of the impeller,coefficient of surface processing,the stress concentration factor of dangerous points,obtained the impeller parts revised-SN fatigue curve.Using the Workbench made a direct transient analysis and the impeller flow solid coupling analysis,get the danger point load spectrum;Crossland model and Matake model defines the name of equivalent fatigue stress.Using the MATLAB language to develop the rain flow count method of load spectrum(4)Extraction procedures;Using the theory of fatigue cumulative superposition to predict the fatigue life of the impeller,the impeller is obtained fatigue life relationship with the size chart.