Strength Analysis And Life Prediction For Centrifugal Compressor Remanufacturing Closed Impeller

Centrifugal compressor is widely used in our country, impeller is its core function part with complex working environment and bearing condition, so it is prone to failure. Centrifugal compressor impeller remanufacturing is a new manufacturing mode based on advanced remanufacturing repair technology, which can make full use of the value of failed impeller, and it meets the country strategic needs to develop circular economy and construct environment-friendly society. To analysis the loads and estimate the residual life of centrifugal compressor remanufacturing impeller is an important research means to ensure the safety work of remanufacturing impeller.This paper combined the national key basic research development plan(973 plan) project "Basic scientific problems of manufactured machinery and equipment" and the Specialized Research Fund for the Doctoral Program of Higher Education "remanufactured mechanical parts service life evolution mechanism and the prediction method research", carrying out strength analysis and life prediction for centrifugal compressor manufacturing closed impeller by using the finite element method based on the current research on the service life of remanufacturing mechanical parts, which can provide the basis for security service of remanufacturing closed impeller.First of all, according to the basic idea and solving steps of the finite element method, this paper put forward the centrifugal compressor remanufacturing closed impeller finite element strength analysis method, combined with the specific analysis process of remanufacturing closed impeller, to consider its working reliability synthetically; and the finite element fatigue analysis method was put forward based on fatigue analysis software Fe-safe, and show the fatigue life analysis flow of remanufacturing closed impeller.Secondly, remanufacture the gap characteristics of a centrifugal compressor closed impeller, and then establish a three-dimensional model of remanufacturing closed impeller. This paper put forward a universal block structured mapping method, and carried out hexahedral finite element mesh for remanufacturing closed impeller by this method. The mesh result show uniform distribution and good quality of the overall grids and manufacturing area grids.Thirdly, in order to analyze the remanufacturing closed impeller strength, this paper used finite element analysis software to analyze centrifugal force, aerodynamic force, assembly stress and prestressed modal. By researching influence of remanufacturing for closed impeller structure strength, it ensured that the remanufacturing closed impeller static strength and dynamic strength to meet the strength requirements, which can guarantee the safe and reliable operation.Finally, this paper determined that the remanufacturing closed impeller meet the low stress and high cycles fatigue characteristics, so it chose the nominal stress method for the fatigue analysis of remanufacturing closed impeller. Then it calculated fatigue life from the beginning service to fatigue failure by determining the the S-N curve of the impeller base material FV520 B, load spectrum information and the cumulative fatigue damage theory.