An Online Fatigue Damage Evaluation Method for Gas Turbine Hot Components

Abstract

The failure of gas turbines’ hot components due to fatigue significantly affects their efficient and stable operation. Conducting online damage assessment of components subjected to complex cyclic loads based on the working conditions of gas turbines can provide real-time reflection of component fatigue damage and achieve the purpose of predictive maintenance. In this study, we propose an online cycle counting method that considers temperature fluctuations during the cycle process. Our method is based on the four-point online rainflow counting method by coupling the counting variable with time, introducing the concept of the duration time for full cycles and half cycles, and incorporating a characteristic temperature that better represents the temperature information during the cycle process. With reference to the characteristic temperature, our proposed method comprehensively considers the form and parameters of subsequent life assessment models. This paper provides a detailed explanation of the proposed method and applies it to the fatigue damage assessment of turbine vanes in a micro gas turbine, thereby verifying its accuracy and applicability.

Research on a Method for Online Damage Evaluation of Turbine Blades in a Gas Turbine Based on Operating Conditions

“…Otherwise, it is considered as a half cycle and ∆T 1 represents the half cycle. This study refers to the references by GopiReddy [31,32] on the rainflow counting method for online evaluation of creep damage, where the relationship between load information and load duration in the case of full cycles is proposed. This study introduces the concepts of cycle start time t T,begin , cycle end time t T,end , and cycle duration t T,hold when considering full cycles.…”