锅炉飞灰含碳量偏高的原因分析  

Cause Analysis on High Carbon Content in Fly Ash of Boilers

作　　者：徐远纲[1] 刘毅[1] 张成[1] 尹俊俊[1] 夏季[1] 杨鹏举[1] 陈刚[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《动力工程学报》2010年第5期325-328,共4页Journal of Chinese Society of Power Engineering

基　　金：广东省科技厅重大科技专项基金资助项目(2008A080800029)

摘　　要：从锅炉试验和煤质特性两方面,分析了某电站锅炉燃用异常煤种时飞灰含碳量偏高的原因.通过锅炉试验排除了设备和运行参数对飞灰含碳量的影响.经热重分析发现:常用煤种和异常煤种的燃烧特性差异较大,异常煤种的着火特性优于常用煤种,但燃尽特性不如常用煤种.对煤样岩相和热解过程中煤焦的比表面积进行了分析,结果表明:异常煤种为混煤,它在热解过程中比表面积的变化规律与常用煤种显著不同;异常煤种在500～700℃热解时,随着热解温度的升高,容易出现焦油堵塞部分孔隙和煤焦熔融现象,使比表面积明显减少,从而导致飞灰含碳量偏高.From the view of boiler test and coal property, causes were analyzed for high carbon content in fly ash of certain utility boiler when the abnormal coal was fired. The cause of effect of the equipment and the operational parameters on carbon content in fly ash was excluded through boiler test. Thermogravimetric analysis indicates that there is large difference in combustion characteristics between the conventional coal and the abnormal coal. The ignition characteristic of the abnormal coal is better than that of the conventional coal, while the burn-out characteristic of the abnormal coal is inferior to that of the conventional coal. Analysis on petrofacies of the coal sample and specific surface area of the coke during pyrolysis were carried out. Results show that the abnormal coal is a blended coal, and the variation of the specific surface area of the abnormal coal is obviously different from the conventional coal during pyrolysis. When pyrolysis of the abnormal coal is carried out at temperature between 500℃and 700℃, with the increase of the pyrolysis temperature, part of the holes will be blocked by the coke and the coke is liable to melt out, resulting in obvious reduction of specific surface area, which is the cause for high carbon content in fly ash of the abnormal coal.

关 键 词：飞灰含碳量 锅炉试验 热重分析 岩相分析 比表面积 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]