基于非线性扩散模型的煤焦O_2/CO_2高温燃烧特征分析  

Study on Characteristics of Coal Chars Combustion in O_2/CO_2 at High Temperatures Based a Nonlinear Diffusive Model

作　　者：费华[1] 胡松[1] 向军[1] 孙路石[1] 宋尧[1] 苏胜[1] 王贲[1] 陈刚[1] 

机构地区：[1]煤燃烧国家重点实验室(华中科技大学),湖北省武汉市430074

出　　处：《中国电机工程学报》2011年第17期32-37,共6页Proceedings of the CSEE

基　　金：国家自然科学基金(51076052;50806025);国家重点基础研究发展规划项目(2009CB226110)~~

摘　　要：偏微分质量守恒方程能够简化为一组线性方程组并用以描述煤焦的反应性,但其计算量偏大,且计算结果也不一定收敛。文中根据反应过程中煤焦孔隙率和表面积之间的非线性变化特征,利用一种逼近的方法简化和求解偏微分质量守恒方程,并最终建立在扩散控制条件下预测煤焦反应性的逼近模型。通过与Rafsanjani模型比较发现,该模型计算得到的数值比Rafsanjani模型计算得到的数值更接近实际情况。基于该模型,分析了焦作无烟煤、云浮烟煤和西阳村贫煤在不同温度下O2/CO2燃烧的特性。Partial differential mass conservation equation can be converted to a set of linear equations, which were applied to depict coal chars reaction. However, the linear equations require a large amount of calculation and the results may not converge. The methodology developed in this work was based on an approximate method for decoupling partial differential mass conservation equation and a nonlinear relationship between the porosity and reaction surface of coal chars, and the approximate model （AM） was finally constructed to predict the reaction rates of coal chars at diffusion control stage. Compared with the Rafsanjani model （QM）, carbon conversion rates predicted by the approximate model are more satisfied to depict the experimental data. Using the model, the characteristics of Jiaozuo anthracite, Yunfu bituminous and xiyangcun lean combustion processes under O2/CO2 atmosphere were analyzed at different temperatures.

关 键 词：非线性扩散模型 孔隙结构 煤焦 O2/CO2燃烧 

分 类 号：TK229[动力工程及工程热物理—动力机械及工程]