Cycle chemistry guidelines for fossil plants: All-volatile treatment. Final report

Technical Report · Mon Apr 01 04:00:00 EST 1996

OSTI ID:270708

Dooley, R B; Aschoff, A F; Pocock, F J

The Interim Consensus Guidelines (ICG) for Fossil Plant Cycle Chemistry were introduced in 1986 to provide the guidance needed to better control cycle corrosion and deposition. The ICG were considered interim; they would be reviewed over the next several years in the light of subsequent research and operating experience in implementing these Guidelines, and then revised as necessary. The guidelines provide a set of target values and action levels for the critical sample points throughout the water and steam cycle for drum and once-through units, covering a pressure range of 600--3,600 psi. In specific, the guidelines--which are applicable to baseload, startup, cycling, and peaking operation--discuss corrective actions to be taken when the guideline limits are exceeded as well as sampling, instrumentation, and monitoring issues. Moreover, for the first time, the guidelines address conversion of a drum boiler to AVT as well as procedures for reacting to contaminant ingress. The major philosophy changes from the ICG involve relaxing the feedwater oxygen limits for all-ferrous feedwater systems, indicating that at least one ppb of oxygen should be present at the economizer inlet and that perhaps an oxygen scavenger is not required. For units with mixed metallurgy feedwater systems, the optimum treatment involves maintaining a reducing environment with an oxygen scavenger. Wherever possible, the guidelines have been organized in tabular and graphical form to facilitate use and present information logically and clearly. Sample points, monitoring parameters, target values, and action levels have been summarized on the familiar single generic-cycle diagrams used in the ICG; these may be modified, as appropriate, and permanently displayed at key locations in each plant.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 270708
• Report Number(s): EPRI-TR--105041
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
AMMONIUM HYDROXIDES
BOILERS
CORROSION PROTECTION
FEEDWATER
FOSSIL-FUEL POWER PLANTS
HYDRAZINE
MONITORING
PHOSPHATES
RECOMMENDATIONS
SAMPLING
SCALE CONTROL
STEAM SYSTEMS
VOLATILE MATTER
WATER CHEMISTRY
WATER TREATMENT