Failure Analysis of Flue Gas Duct in a Steam Power Plant

Abstract

Power plant consists of systems that affect each other. The main two cycles in power plant are Water – Steam and Air – Gas cycles. Flue gas duct is used in air-gas cycle to release the flue gas from the furnace to the atmosphere. The cracks and holes occur in the gas duct as a result of corrosion, which resulted in allowing the air ingress into the duct and consequently cause a chemical reaction with flue gas, this reaction creates a sulfuric acid layer and hence accumulate on the internal surfaces of the duct and transfer to Induced Draft Fan (IDF). The main objective of this work is to introduce a composite layer to Corten Steel (the material from which the gas duct made) to improve a corrosion resistance. This coating layer consists from serval nanoparticles (ZnO, ZrO2, SiO2 and NiO) as reinforcement phase with epoxy resins matrix. The surface roughness profiles of Nano-epoxy composite coating show an improvement in surface roughness compared to the original corten steel without coating. Furthermore, XRF and XRD analysis shows the Nano-epoxy composite coating elements and the increment of element that improve corrosion resistance.