Abstract:

The transformation mechanism of minerals in coal ash under different atmospheric conditions affects the melting and slagging process of coal. In order to study the melting characteristics of Zhundong coal under oxygen-rich/H₂O-O₂ atmosphere, and provide reference for preventing the slagging of Zhundong coal-fired boilers, the charge coupled device (CCD) camera was used to record the deformation process of the pulverized Zhundong coal on the hot stage. By calculating the sampling areas of the pulverized coal at different temperatures, the melting temperatures corresponding to the characteristic change points of the pulverized coal areas were obtained. The temperatures at which Zhundong coal powder began to melt under different oxygen-rich/H₂O-O₂ atmosphere conditions were compared. The study have shown that as the oxygen concentration increases, the temperature at which the coal powder begins to melt decreases. As the water vapor concentration decreases, the temperature at which the coal powder begins to melt increases. Both water vapor atmosphere and oxygen-rich atmosphere can promote the melting behavior of Zhundong coal.

Key words: Zhundong coal, melting characteristics, oxygen-rich atmosphere, H₂O-O₂ atmosphere, hot stage experiment, charge coupled device (CCD) camera