不同粒度煤粉的表面结构与燃烧特性研究  

Study of the Surface Structure and Combustion Characteristics of Pulverized Coal in Various Particle Sizes

作　　者：徐远纲[1] 张成[1] 夏季[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,湖北武汉430074

出　　处：《热能动力工程》2010年第1期47-50,共4页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金资助项目(50721005);广东省科技厅重大科技专项基金资助项目(2008A080800029)

摘　　要：制备了4种不同粒度的平三煤和大友煤煤粉,分别采用低温饱和氮气吸附的方法和热天平研究了煤粉的表面结构特性和煤粉的燃烧特性。实验结果表明:随着煤粉粒度的减小,煤粉的孔隙结构发生变化,比表面积和孔容积均增大,表面结构复杂,致使分形维数增大,有利于煤粉颗粒的燃烧,因此,平三煤的着火温度降低了14℃,表观活化能均降低了12.3kJ/mol,燃尽率提高了9.81%,大友煤的燃烧特性变化规律相似。此外,煤粉颗粒的分形维数还能在一定程度上表述煤粉的燃烧特性,因此,分形维数可为煤粉燃烧特性的评价提供一种新的途径。Four particle sizes of Pingsan-originated and Dayou-originated coal were prepared. The surface structure and combustion characteristics of the pulverized coal in different particle sizes were investigated by using respectively the low-temperature saturated nitrogen adsorption method and a thermobalance. The test results indicate that with a decrease of the particle size of the pulverized coal,a change will occur to the pore structure of the pulverized coal. Both the specific surface area and pore volume will increase,and the surface structure,become complicated,thus leading to an increase of the fractal dimension and facilitating the combustion of pulverized coal particles. As a result,the ignition temperature of Pingsan-originated coal goes down by 14 ℃,the apparent activation energy decreases by 12.3 kJ/mol and the burnt-out rate rises by 9.81%. The variation law of the combustion characteristics of Dayou-originated coal is similar to that of Pingsan-originated coal. In addition,the fractal dimension of the pulverized coal particles may represent the combustion characteristics of the pulverized coal to a certain extent. Hence,the fractal dimension will provide a new approach for evaluating the combustion characteristics of the pulverized coal.

关 键 词：煤粉 粒度 表面结构 分形维数 燃烧特性 

分 类 号：TQ534[化学工程—煤化学工程]