Erosion, Corrosion and Deposits in Gas Turbines Burning Heavy, High Sulphur Fuel Oil

Abstract

Ash deposits, fuel treatment and fuel specification are considered between the most important technical factors that require specific consideration for economical use of heavy fuel oils in gas turbines or combined cycles. Ash deposits built in the hot gas path of gas turbines can cause severe erosion and corrosion of blades and vanes, besides the fouling associated to the Mg-base additive used in order to inhibit vanadium, a significant contaminant in residual fuel oils. Erosion, corrosion and ash deposition constitute the central problem affecting turbine reliability and service life when using low quality fuel oils. The aim of this paper is to show how these detrimental processes are interrelated in gas tuibines using heavy high sulfur fuel oils.The deposition rate for an ash on the turbine is influenced by the duty cycle, the contaminants in the fuel (particularly Na, V and S), the type and dosage of Mg inhibitor and the gas path temperatures. The duty cycle significantly 267

Multi-Walled CNT Reinforcement to Thermal Spray Coatings

“…The Na, V, K and S are present in fuel as impurities. These impurities form low melting point compounds and get deposited on the surface of material and subsequently induce corrosion [13,14]. These impurities reach with each other to form Na 2 SO 4 , V 2 O 5 and other complex vanadates.…”