Optimum feedwater chemistry

Technical Report · Fri Dec 01 04:00:00 EST 1995

OSTI ID:227017

Dooley, B

The purity of boiler water, feedwater and steam is without doubt one of the most important criteria for ensuring component availability and reliability in utility fossil plants. Its influence touches every major component and it is often called the {open_quote}life blood{close_quote} of the plant. Only with improvements in cycle chemistry control will there be a marked overall improvement in the availability of the U.S. fossil utility industry. In the boiler the equivalent availability loss in U.S. power plants attributable to boiler tube failures is over 3%. 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-fueled power plants. Out of a total of 35, fifteen boiler tube failure mechanisms are influenced by, or may possibly be influenced by, plant cycle chemistry. Turbine availability losses attributed to fossil-fired plant cycle chemistry are primarily L-1 blade failures due to corrosion fatigue and turbine disk cracking due to stress corrosion. Also deposition of impurities in steam in the turbine can result in marked turbine performance losses. A 0.076 mm thick deposit uniformly distributed over the steam path of the turbine decreases flow through the turbine by 1% and causes a reduced turbine efficiency of 3%.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 227017
• Report Number(s): EPRI-TR--105876; CONF-9509192--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CORROSION
CORROSION PRODUCTS
FEEDWATER
FEEDWATER HEATERS
THERMAL POWER PLANTS
WATER CHEMISTRY