STATE OF THE ART IN FOSSIL PLANT CYCLE CHEMISTRY

Cycle chemistry-related boiler tube and turbine blade or disk failures are the leading causes of availability loss in fossil-fired utility and industrial power plants worldwide. For example, the equivalent availability loss in US power plants attributable to boiler tube failures is over 4%. More than 40,000 failures have been recorded there in the last decade [1]. Recent statistics compiled by the North American Electric Reliability Council indicate that boiler tube failures are responsible for approximately 70% of the forced outages and over 50% of the lost avail­ability of fossil-fuelled power plants. Table 1 summarizes the boiler tube damage mechanisms currently known. Out of a total of twenty eight, twelve boiler tube failure mechanisms are influenced by, or may possibly be influenced by, plant cycle chemistry.