Abstract
Ash deposition on the heat exchanger tubes reduces the overall heat transfer coefficient due to its low thermal conductivity. This study focuses on the relationship between coal ash mineral and furnace heat transfer. The ash deposition tests were conducted using a refractory furnace. The structures of ash adhered to the water-cooled probe were investigated using SEM analysis. As a result, it was found that the coal ash which caused the heat transfer decrease had a unique porous structure. It was also found that its coal has a lot of Kaolinite mineral with crystal water using CCSEM analysis. It is suggested that the porous ash come from Kaolinite mineral generate the thermal insulating layer on the heat exchanger tube and decreases heat transfer in pulverized coal boiler.
