Parameter monitoring for corrosion control of utility gas turbines. Interim report

Technical Report · Wed Mar 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/6866322· OSTI ID:6866322

Boenig, F.

Hot corrosion is a significant durability limiting factor in industrial gas turbine engines. It is caused primarily by alkali sulfates depositing on the turbine airfoils. The object of this program is to determine from field and laboratory test data the conditions that cause deposition of these corrodents and to define an engine control system that will minimize their effect. Field data on 600 engines was statistically analyzed to determine the influence on hot corrosion of fuel type, engine washing, air filtration and the proximity of the engine sites to oceans. Laboratory tests are being conducted on turbine materials, with and without protective coatings, to assess relative resistance to corrosion. Corrosion rates in the presence of sodium sulfate alone and with carbon, vanadium and lead are being defined. The primary source of sodium is airborne sea salt and contaminated fuel. Atmospheric and fuel salt concentrations have been measured at a variety of U.S. sites. Sodium ion concentrations in the air stream inside engines were monitored for evidence of impulsive shedding of accumulated salt. An engine control system which will monitor the atmospheric and fuel-borne salt concentrations and signal the need for an engine water wash cycle to remove accumulated salt before corrosion has started is being defined. The control can also reduce power to slow the corrosion rate if the wash is not performed. The program is approximately 50% complete at this point. Results show that water washing reduces the incidence of corrosion and that turbine materials can tolerate alkali sulfates for a limited period before hot corrosion commences. Remaining work will be directed at determining when the corrodents are released and/or deposited on the turbine. Ideally the control system will recognize the likelihood of this occurrence and signal a wash cycle.

• Research Organization: United Technologies Corp., South Windsor, Conn. (USA). Power Systems Div.
• OSTI ID: 6866322
• Report Number(s): EPRI-AF-665
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104* -- Fossil-Fueled Power Plants-- Components
ALKALI METAL COMPOUNDS
CHEMICAL REACTIONS
CORROSION
CORROSION PROTECTION
CORROSIVE EFFECTS
GAS TURBINES
INDUSTRIAL PLANTS
MATERIALS TESTING
OXYGEN COMPOUNDS
POWER PLANTS
SODIUM COMPOUNDS
SODIUM SULFATES
SULFATES
SULFUR COMPOUNDS
TESTING
THERMAL POWER PLANTS
TURBINES
TURBOMACHINERY