梁斌, 冯强, 白浩隆, 武琼, 宋华, 杨晓辉, 蓝天. 煤泥干粉在流化床中燃烧特性的实验研究[J]. 煤炭学报, 2018, 43(S2): 560-567. DOI: 10.13225/j.cnki.jccs.2018.1069
引用本文: 梁斌, 冯强, 白浩隆, 武琼, 宋华, 杨晓辉, 蓝天. 煤泥干粉在流化床中燃烧特性的实验研究[J]. 煤炭学报, 2018, 43(S2): 560-567. DOI: 10.13225/j.cnki.jccs.2018.1069
LIANG Bin, FENG Qiang, BAI Hao-long, WU Qiong, SONG Hua, YANG Xiao-hui, LAN Tian. Combustion characteristics of dry coal slime powders in a fluidized bed[J]. Journal of China Coal Society, 2018, 43(S2): 560-567. DOI: 10.13225/j.cnki.jccs.2018.1069
Citation: LIANG Bin, FENG Qiang, BAI Hao-long, WU Qiong, SONG Hua, YANG Xiao-hui, LAN Tian. Combustion characteristics of dry coal slime powders in a fluidized bed[J]. Journal of China Coal Society, 2018, 43(S2): 560-567. DOI: 10.13225/j.cnki.jccs.2018.1069

煤泥干粉在流化床中燃烧特性的实验研究

Combustion characteristics of dry coal slime powders in a fluidized bed

  • 摘要: 为了探索煤泥燃烧利用的新途径, 首先研究了煤泥干粉的燃烧动力学, 然后在高2 000 mm、内径100 mm实验室规模的流化床中系统研究了其燃烧特性。结果表明, 煤泥干粉燃烧为一级反应。在床温900℃、床料为40目石英砂的条件下, 当u/umf>6, 即操作气速过高时, 由于煤泥干粉粒径较细, 煤泥在床内停留时间较短, 燃烧不充分, 炉内轴向温度与烟气中CO, SO2, NOx等污染物浓度波动大;当u/umf<2时, 由于气速过低, 流化质量差, 密相区物料出现沉积, 导致炉内煤粉出现“爆燃”;在u/umf为2~6之间, 随着流化气速增加, CO, SO2, NOx等烟气组分均明显增加。当以相同Ca/S摩尔比加入石灰石后, 随流化气速降低, 气体停留时间增加, SO2和石灰石的气固接触改善, 炉内脱硫效率提高。

     

    Abstract: Aiming at exploring new techniques for coal slime combustion, the combustion kinetics of Dry Coal Slime Powders (DCSP) was firstly investigated by a thermogravimetric analyzer.Then, the combustion characteristics of the DCSP was further measured in a fluidized bed with a height of 2 000 mm and an inside diameter of 100 mm.The results showed that the combustion of DCSP can be well correlated by a first-order reaction kinetics.At the bed temperature 900℃ with 40 mesh quartz sand as the bed material, the axial temperature profile and the CO, SO2, NOx concentrations fluctuate significantly when u/umf>6, because the residence time of DCSP in the bed is too short to allow the complete combustion to be achieved at higher gas velocities.At lower gas velocities (u/umf<2) the fluidization quality is poor, the flammable fine coal slime powders accumulated in bed bottom lead to sudden and explosive combustions, causing the bed temperature to rise sharply.When u/umf is between 2 and 6, the CO, SO2, NOx all increase with the increase of u/umf.Experimental data also revealed that at the same Ca/S molar ratio, the SO2 removal efficiency by in-bed limestone increase with the decrease of gas velocity, which is resulted from the increased residence time at lower gas velocities.

     

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