Experimental Study on Slagging Characteristics of High Alkali Coal Blended with Low Sodium Coal
Aiming at the problem that the boiler of Zhanjiang steel power generation unit is prone to fouling and slagging on the heating surface when burning high alkali coal,a mitigation measure by blending low sodium coal was proposed.In order to optimize the coal blending and burning scheme,the coal quality and combustion characteristics of high alkali coal and low sodium coal were analyzed firstly,and then the blended coal combustion experiment was carried out based on the"settling furnace-depositing furnace"system,and the coal ash composition index was used to predict the slagging characteristics of blended coal under different ratios.The results show that high alkali coal has the characteristics of high volatile,low ash,high calorific value and high alkali metal content.It has good ignition and burnout performance,but strong slagging tendency.The reference value of the evaluation index of coal slagging tendency according to the melting temperature of coal ash is limited.In the index of predicting slagging tendency of coal species based on coal ash composition,the sodium equivalent of coal ash comprehensively considers ash content and alkali metal content of coal species,which is more consistent with the actual situation than the prediction results of alkali acid ratio,silicon aluminum ratio and iron calcium ratio.The slagging tendency of high alkali coal can be effectively reduced by blending combustion with low sodium coal.The effect of slagging tendency is more obvious with the increase of blending proportion of low sodium coal.When 75％DN2 or DN3 is blended,the slagging tendency of blended coal is lower than that of DN4 alone,which can solve the problem of slagging easily when burning high alkali coal alone.
high alkali coallow sodium coalblended coal combustioncoal ash compositionslagging characteristics
万方数据
维普
