Turbine steam, chemistry, and corrosion. Final report

This report contains a state-of-art review of knowledge concerning the chemistry and corrosive effects of turbine steam containing impurities. The information presented is based on experience from industrial practice, from a comprehensive review of the various subject literatures involved, and from discussions with specialists from many industrialized countries. The objective here is to identify the extent of knowledge now available with regard to turbine steam chemistry and corrosion. This work represents the initial phase of a new EPRI Research and Development Project on Turbine Steam Chemistry and Corrosion, which has been initiated in conjunction with an international collaborative research program. The purpose of this project is to gain additional knowledge of the deposition behavior of common steam impurities under turbine operating conditions. This report and the follow-on project work is intended to advance the state of knowledge of the phenomena involved in the steam turbine corrosion, erosion, scale and deposit formation, and moisture nucleation, and to achieve a quantitative understanding of the phenomena involved, so that predictive theories of deposit formation and erosion may be developed. Impurity concentration mechanisms are discussed in Chapter 2. Distribution and effects of oxygen in turbine steam are discussed in Chapter 3. Liquid-vapor chemical transportmore » due to vaporous carry-over is discussed in Chapter 4. Steam flow and moisture nucleation in turbine stages is reviewed in Chapter 5 from the subject literature. Effects of steam chemistry on droplet nucleation is discussed in Chapter 6 with respect to the influence of impurities on droplet formation. Conclusions and Recommendations are presented in Chapter 7, based on overall consideration of the above topics.« less