EFFECT OF COAL CHLORINE ON THE FIRESIDE CORROSION OF BOILER FURNACE WALL AND SUPERHEATER REHEATER TUBING/

EPRI studies have identified boiler tube failures as the principal cau se of loss of power plant availability worldwide. A significant propor tion of the failures in the furnace wall and pendant/platen superheate r and reheater stages are the result, either directly or indirectly, o f excessive metal loss by fireside corrosion. Despite fundamental diff erences in the corrosion mechanisms active on furnace walls (gaseous) and superheater/reheater stages (molten salt), much of the worsening f ireside corrosion problems experienced in both sections on UK plant in the 1960s and 1970s was attributed to fuel chemistry, in particular t he coal chlorine content. This paper explores the more recent history of fireside corrosion in CEGB and PowerGen Stations as extracted from a Literature survey undertaken as the inaugeral exercise in a jointly sponsored EPRI/PowerGen project into the role of combustion parameters and fuel chemistry on fireside corrosion. The current view of the imp act of coal chlorine on the wastage mechanisms concerned in each boile r stage is also detailed.