Int. J. of Power and Energy Conversion   »   2015 Vol.6, No.1

 

 

Title: Useful life estimation and condition inspection of a 28,800 kW gas turbine components

 

Authors: Alberto Luna-Ramírez; Rafael García-Illescas

 

Addresses:
Instituto de Investigaciones Eléctricas, Reforma 113, Col. Palmira, 62490, Cuernavaca, Morelos, México
Instituto de Investigaciones Eléctricas, Reforma 113, Col. Palmira, 62490, Cuernavaca, Morelos, México

 

Abstract: In the present work, the current condition and non-destructive testing results of a gas turbine rotor are presented. Moving blades and nozzles of a turbo generator unit were inspected. Important longitudinal cracks were found in convex and concave sides of most nozzles blocks after more than 20 years of operation. Estimation of life prediction by means of a simplified method programmed in Matlab was elaborated in order to calculate fatigue and creep damage in the rotor due to steady and transient operation during normal start-ups and shut-downs of the turbine. Fatigue models were implemented in the programme taking into account low cycle fatigue phenomenon and high temperature effects on thermal and mechanical properties of rotor material. A simplified creep analysis calculation was accomplished by using a programme for mathematical calculations. Some conclusions on fatigue life and creep predictions were obtained and some recommendations for reliable operation are issued in order to improve mechanical behaviour and extend useful life of the main hot gas path components.

 

Keywords: gas turbines; turbine rotors; thermo-mechanical stresses; fatigue modelling; creep damage; life prediction; turbine blades; condition inspection; nondestructive testing; NDT; longitudinal cracks; nozzles blocks; simulation; high temperature effects; mechanical behaviour; hot gas path components.

 

DOI: 10.1504/IJPEC.2015.068437

 

Int. J. of Power and Energy Conversion, 2015 Vol.6, No.1, pp.47 - 62

 

Available online: 30 Mar 2015

 

 

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