【摘要】 基于两步反应动力学机理(包括燃料热解和燃料的氧化),建立了二维非稳态燃料填充床阴燃的数学模型.该模型既考虑了固相和气相之间的热传递,也考虑到了气体在多孔介质内扩散系数的变化.辐射换热采用扩散近似方式予以表达.数值模拟结果表明:阴燃传播速度随着来流速度的增大而增大,但当来流速度超过0.35cm/s时,阴燃速度增长幅度大大减小;来流速度对阴燃最高温度影响不大.同时还模拟了燃料阴燃过程中气体组分(O2、CO、CO2及H2O)和固体成分(燃料、焦炭)的变化以及温度分布情况.图8,表2,参12.更多还原

【Abstract】 Based on a two-step kinetic mechanism (including fuel pyrolysis and fuel oxidation), a two-dimensional unsteady numerical model was presented for reverse smoldering propagation in horizontally packed beds of cellulosic materials. The model takes heat transfer into account between solid phase and gas phase, and the diffusion coefficient varies with the temperature. Radiation heat transfer was incorporated using the diffusion approximation. The results show that increasing the inlet airflow velocity with increasing smoldering velocity. But the increasing amplitude of smoldering velocity is largely reduced at inlet airflow velocities greater than 0.35cm/s. And the inlet airflow velocity has little effect on the average maximum temperature. The evolution of gas species (including O2、CO、CO2 and H2O ) and solid compositions (including foam and char) are numerically studied. The temperature profile is simulated for smoldering cellulosic materials. 8figs.,2tabs.,12refs.更多还原