Investigations of fireside corrosion for biomass co-firing condition in boiler tube

摘要

Utilization of renewable resources for power generation are more important due to portfolio standards (RPS) action in Korea. One of feasible method for utilizing renewable fuels is, Co-firing of biomasses in coal fired power generation plant. However, co-firing biomasses may cause additional problems such as increased ash deposition and corrosion rate due to significant presence of chlorine contents as compared coal. The high temperature corrosion caused by interaction between boiler tube and combustion exhaust gas elements such as chlorides. Lab scale experiment was performed using lab scale equipment set up to investigate mechanism of corrosion formation and factors influencing boiler tube corrosion. In this study, super-heater material SA213 T91 was used to observe high temperature corrosion mechanism in boiler tube material. In addition, three different experimental conditions(various SO_x content conditions) with corrosion reagent material (chlorine) were considered in this test to observe and analyze the factors affecting corrosion mechanisms. The corrosion test specimens are analyzed by using Scanning Electron Microspe SEM to observe the corrosion scale and deposit microstructures on the polished cross section of corrosion expose test specimens.