Combustion experiment and gray relational analysis of coal water slurry balls in fluidized bed

In order to study combustion of coal water slurry (CWS) in fluidized bed boiler, man-made CWS ball was used as simulation of the ball formed from CWS drop which failed from furnace top to bed. They were dropped into thermal state fluidized bed furnace whose bed material was quartzite particle under various operation parameters (bed temperature, fluidization number, bed height) to analyze their combustion performance. The bed temperatures were 650°C, 750°C, 850°C and 950°C.The fluidization numbers W were 3, 3.5, 4, and 4.5. The bed heights were 30 mm, 50 mm, 70 mm and 90 mm. The CWS balls were taken out after five various time periods which were 15 s, 30 s, 45 s, 60 s and 75 s and mass ratio of their residue fixed carbon to original fixed carbon were calculated through which the influence of every parameter was analyzed. The datum were processed using gray relational analysis and the degree of their influence to the ratio were sorted. The conclusion is that the influence of bed height is the least, fluidization number has greatest influence in primary stage and final stage, and bed temperature contributes most in intermediate stage.