循环流化床锅炉飞灰的分形特性  

Fractal characteristics of fly ash in circulating fluidized bed boilers

作　　者：樊保国[1] 刘兴国[1] 刘海玉[1] 车丹[1,2] 金燕[1] 

机构地区：[1]太原理工大学电气与动力工程学院,山西太原030024 [2]山西大学工程学院,山西太原030013

出　　处：《煤炭学报》2014年第6期1154-1158,共5页Journal of China Coal Society

基　　金：教育部高等学校博士学科点专项科研基金资助项目(20101402110011);国家自然科学基金资助项目(51206116)

摘　　要：为分析循环流化床飞灰的微观特性,以某480 t/h循环流化床锅炉为研究对象,通过压汞仪和扫描电镜研究其飞灰的分形特性。研究结果表明,循环流化床锅炉飞灰含碳量随粒径的分布具有峰值特性,在37μm处,含碳量达到最大值（峰值区）,48-78μm为低含碳区。飞灰具有良好的分形特性,压汞仪测得的峰值区飞灰颗粒孔比体积、比表面积和孔隙率较大,而其分形维数较小（2.227）,低含碳区飞灰分形维数为2.694。峰值区飞灰颗粒为致密的实心体,低含碳区飞灰颗粒为蜂窝状。基于SEM图像计算的分形维数与基于压汞实验所得的飞灰分形特性结论一致。In order to study the microscopic characteristics of fly ash in circulating fluidized bed boilers,a CFB boiler in capacity of 480 t /h was taken as an object to study fractal characteristics of fly ash by mercury porosimetry and SEM. The results show that the distribution of carbon contents in fly ash is of a peak with diameters. For the fly ash of37 μm in diameter,the carbon content has the maximum value called the peak zone. When the diameter is 48-78 μm,the zone is the low carbon one because of low carbon contents. The fly ash in the circulating fluidized bed boiler is of fractal characteristics. In the peak zone the specific volume,the specific surface area and average porosity are larger than in the low carbon one,and the fractal dimension is 2. 227 which is smaller than in the low carbon one（ 2. 694）.By SEM the image of fly ash in the peak zone presents a dense solid body,and the image in the low carbon one presents a honeycomb body. The fractal dimension based on SEM is in accordance with the result by mercury porosimetry.

关 键 词：循环流化床锅炉 飞灰 含碳量 分形维数 

分 类 号：TQ534.9[化学工程—煤化学工程]