基于简单碰撞理论煤粉燃烧动力学模型的研究——PART Ⅰ:理论建模与热重实验  

STUDY ON THE REACTION KINETICS MODEL OF PULVERIZED COAL COMBUSTION BASED ON SCT-PART Ⅰ: THEORY AND TGA

作　　者：傅培舫[1] 方庆艳[1] 姚斌[1] 周怀春[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：《工程热物理学报》2005年第2期331-334,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50476070)

摘　　要：本文根据反应动力学的简单碰撞理论(SCT),建立了气固两相反应通用模型,进一步研究了煤焦燃烧和燃尽的统一动力学模型;粉煤悬浮燃烧时挥发分的析出模型也可包含在该模型中;该模型充分考虑了粉煤在热天平中与在炉内燃烧条件下氧气浓度和氧气可达比表面积变化规律的差异,并给出了计算活化能函数和氧气可达比表面积的新方法,可提高利用热天平获取的动力学参数对炉内煤粉燃烧速率预报的准确性。通过热重分析和已经报道的试验数据对模型的合理性进行了检验。Recently, the process of char burnout is extensively concerned. Global model widely used cannot predict the extent of char burnout at the latter burning stage. Based on the Simple Collision Theory (SCT) of chemical reaction kinetics, general model is built for gas-solid reaction; Pulverized coal (p. c.) char combustion is considered as the results of strike and oxidation of oxygen molecules on the p.c. surface, and the numbers of effective strike is determined by Boltzmann factor. The SCT model is accounted for the changes of the ratio of carbon to ash on the p.c. surface which make the numbers of effective strike decrease and the burning rate quickly down. It is adequately considered that the difference of the oxygen concentration and accessible specific surface area(OASSA) during p.c. combustion in TGA and furnace respectively, and a new method is given for calculating the activation energy function and the OASSA, the p.c. combustion rate in furnace predicted more accurately by SCT model. The rate of devolatilization can be predicted at a first stage by SCT model for suspended combustion of p.c.; The predicted results of burning rate for the p.c. combustion in a semi-industrial jet flame furnace are consistent with the experimental data.

关 键 词：煤粉燃烧 SCT动力学模型 活化能函数 氧气可达比表面积 TGA 

分 类 号：TK16[动力工程及工程热物理—热能工程]