Fundamental considerations of the effects of flexible operation on the fatigue of power plant components

ABSTRACT

High temperature components, such as boiler parts or live steam lines in power plants, are subjected to operating conditions that may fully utilise the design reserves. A higher demand for flexibility in operation results in an increased number of thermal cycles.

Commonly, code-based online calculation of a component’s degree of exhaustion relies on individual calculation of creep fatigue and cyclic fatigue. Sensor measurements from online monitoring (pressure and temperature) allow for the abstraction of load profiles based on data taken from in-service conditions.

Our investigations and analyses of components include FEM supported evaluation of stress intensity factors and load profiles determined from in-service conditions.

Based on data from online measurements, the impact of flexible operation and different boundary conditions, such as component geometry, are illustrated. The calculated results can be directly related to the remaining service life of a component and allows for an optimised fatigue life management.

KEYWORDS:

• Power plant components
• fatigue life management
• thermal fatigue
• flexible operation

Disclosure statement

No potential conflict of interest was reported by the authors.