Effect of coal-fired power plant flexible operating method on boiler header fatigue life

Due to the increase in renewable power generation sources, flexible operation is being required for large-capacity coal-fired power plants. Fatigue needs to be considered because the possibility of fatigue damage to equipment increases compared with rated operation. Existing studies qualitatively analyzed the impact on power generation facilities, and quantitative comparison studies were not conducted. Accordingly, this study comparatively analyzed the impact of flexible operation methods on the lifetime of boiler headers. Finite element analysis models were created to analyze stress in transient operation conditions, and fatigue rupture life was derived using fatigue test data from previous research. Then, as a result of assessing the fatigue life according to design criteria, the low load operation mode was confirmed to have a fatigue life 2.57 to 4.61 times longer than the start & stop mode. This study is intended to provide technical information for decision-making on flexible operation methods of power plants.