褐煤流化床提质性能研究

针对褐煤水分高、发热量低、易风化自燃等特点,以内蒙古褐煤为研究对象,进行了褐煤静态干燥实验和褐煤提质多因素实验。以O2体积分数10.5%的烟气为干燥介质,在分析褐煤流化床提质干燥机理的基础上,对褐煤进行流化床动态提质实验。结果表明:褐煤提质水分控制在5%左右为宜。褐煤粒级小于3 mm时,温度对煤样干燥速度影响最大,其次是煤样粒度,风速对干燥速度影响最小。确定全粒级、0.5~1.25、1.25~2、2~3 mm褐煤临界流化风速分别为38、20、40和50 m3/h。褐煤适宜提质温度和时间分别为200~240℃和5~8 min。最后建立了褐煤提质模型,说明褐煤提质规律与提质介质温度、风速密切相关,该模型对褐煤提质生产具有指导作用。 The lignite has the disadvantages of high moisture,low calorific value and easy spontaneous combustion.The essay took lignite in Inner Mongolia as object,carried out the lignite static drying test and upgrading multi-factor test.Taking the flue gas in which the O2 volume fraction was 10.5% as drying medium,the serial experiments of fluidized bed upgrading based on the analysis of fluidized bed upgrading principle were conducted.The results showed that,the optimum moisture was around 5%.When the lignite size was below 3 mm,the temperature affected the drying rate most,followed by lignite size and air speed.The paper determined the critical fluidized air speed for total size fraction,0.5 to 1.25 mm,1.25 to 2 mm,2 to 3 mm was 38,20,40,50 m3/ h respectively.The optimum upgrading temperature and time was 200 to 240 ℃ and 5 to 8 minutes.At last,an upgrading model was built which had a guidance function to lignite upgrading