Evaluation of Cyclic Operation of Heat Recovery Steam Generators — A Practical Approach

Abstract

In the past, power plants for the most part did not operate in cyclic service. Today the demand for dispatchable operations is a common requirement for many new facilities. In this report practical considerations for evaluating and accommodating high cyclic operations of Heat Recover Stream Generators, (HRSG), are discussed. A general understanding of the difference between Low Cycle and High Cycle Fatigue is provided, how fatigue causes damage is discussed and the operating parameters that are most influential are identified. Non-analytical methods that can be used to minimize the effects of fatigue and how these options can greatly decrease damage are discussed. Typical HRSG operating cycles that should be considered in life evaluation are defined. Finally, a practical approach to evaluating the fitness of the equipment for high cyclic operations is presented along with an example of how this method can be used.