13th International Conference on Fracture June 16–21, 2013, Beijing, China -1- EPRI Initiatives related to Flexible Operation of High Temperature Power Plant Jonathan Parker1,*and John Shingledecker1 1 EPRI, 1300 West WT Harris Blvd, Charlotte NC 28262, USA * Corresponding author: jparker@epri.com Abstract Variable demand and an increasing range of electricity supply methods are such that steam plant must perform under cyclic operation. Indeed, the multiplicity of generating options means that even defining a ‘typical’ cycle is difficult. Quantification of the range of potential damage mechanisms is even more complex. In response to the need for greater understanding of cyclic performance issues in high energy components, in 2006 EPRI initiated a series of Annual Expert Workshops on Creep Fatigue. These discussions identified key issues and areas for development related to the design and performance under transient operation. Summary documents, produced from each of the annual meetings, have helped guide this international effort in the field of creep-fatigue. It is apparent that a coordinated effort is critical to ensuring that outcomes are meaningful and effective. Excellence in science and engineering is necessary in aiding the electricity supply industry to meet current challenges associated with safe and reliable operation of plant. The present paper documents the current state of knowledge on creep fatigue behaviour and outlines achievements from the EPRI collaborative work. The overall goal of this effort is to provide the basis of a comprehensive approach to design and life management of components that are subject to creep-fatigue conditions. Keywords Creep, Fatigue, Flexible Operation 1. Introduction Utilities increasingly need to adopt generating practices that involve cycles. The number, magnitude, and complexity of the cycles associated with transient type operation have all increased. Thus, starts and stops as well as changes in generating output can lead to problems associated with thermal and /or mechanical loading as well as potential issues with water chemistry and corrosion. For components which operate at high-temperature, damage associated with transient operation is frequently called creep-fatigue. However, even in this group of components, specifics of damage mechanisms will vary widely. A schematic illustration of the primary options is shown in Fig 1. Figure 1. Schematic illustration of different forms of creep-fatigue type damage seen in high energy components.
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