改进随机孔模型解析生物质焦燃烧特性

MODIFIED RANDOM PORE MODEL TO EXPRESS THE COMBUSTION CHARACTERISTICS OF BIOMASS

主要对经典随机孔模型进行改进,对原模型中固定的结构参数ψ进行随机化处理(即不限定ψ数值),从而得到反应过程中结构参数的演化行为。通过与经典随机孔模型比较发现,在不限定ψ数值的情况下,计算得到的数值比传统方法得到的数值更接近实际情况。ψ随反应的进程也呈现一定的变化趋势。利用该方法,分析了我国农业生物质热解焦的燃烧特性。

Evolution characteristics of particle physical structure increase the complicate degree of this research. The RPM is the only one that can interpret the maximum in the curves of experiment, since it accounts for the overlapping of react-ing surfaces as they grow, the reaction surface being the interface between the nonovedapped portion of the cylindrical pores surface and the unreacted carbon. Recently, many researchers found the inconsistent of experiment data and pre-diction of RPM which was caused by the definition of structural parameter Ψ. In this paper, the RPM is modified by ran-domization the structural parameter Ψ. Based on this modified process, changing characteristics of Ψ is clarified. Com-pare to the result of RPM and DRPM, we find that MRPM is satisfier to explain the combustion process of biomass char, especially at the end of combustion. Ψ values change with specific characteristic which could be explained by the pore structure feature. Using the MRPM, isotherm combustion processes of three Chinese agricultural biomass chars are ana-lyzed.