Analysis on High Temperature Corrosion Characteristics of Water Wall in Boiler with Storage Coal Pulverizing System
A detailed analysis was conducted on the high-temperature corrosion characteristics of a boiler with the storage pulverized-coal milling system,including the corrosion area,coal powder eroding water walls,coal powder unburnt conditions and the habitual operation mode of the operating personnel.Research has found that the most severely corroded area of the furnace is located below the tertiary air nozzles,rather than that below the SOFA nozzles,which is a significant difference from the high-temperature corrosion of the direct firing pulverizing system boiler.In addition,another corrosion characteristic in this furnace was found,that is,along the counterclockwise tangential direction of the primary air,from upstream to downstream areas,the locations where the corrosion occurs in the water-cooled wall tubes can be sorted into three categories,the fire-facing side of the tube,the middle area of the tube,and the backfire and fire-facing sides of the tube.The large unburnt coal powder eroding water wall and the high H2S concentration are the main causes of severe corrosion.The burnout rate of unburned pulverized coal obtained by extracting flue gas adjacent to the water wall where the coal powders erode is 73.5％-80％.After the pulverized coal is heated in the furnace,the pyrite sulfur is basically decomposed,and the remaining sulfur is mainly organic sulfur.
the storage pulverized-coal milling systemboilerhigh temperature corrosionflame eroding water wallsH2S
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维普
