【摘要】 将固态颗粒填料床视为由规则颗粒堆积而成的松散多孔介质,在推导出传热控制机制下微元体综合速率的基础上,采用局部热不平衡假设建立了一维固定床中石灰石热分解反应与传热、传质耦合的数学模型,运用有效容积法对其离散求解,并采用文献中实验数据对模型进行验证.计算了不同条件下颗粒物料层内气体和固体骨架的温度场、产物气体浓度场以及固体转化率分布,以得到多孔介质体系内固有化学反应时的传热传质规律.研究结果对具有强吸热反应的固定床反应器的设计和运行具有一定的参考作用.更多还原

【Abstract】 On the basis of the derived overall rate of decomposition in representative elementary volume in the heat transfer controlled regime, a one-dimensional mathematical model for the calcination of limestone coupled with heat and mass transfer in a packed bed was established by applying local thermal non-equilibrium assumption. Adopting a finite volume method to solve this model numerically, the mathematical model was validated by comparison with single particle experiment in the literature. The gas temperature and solid matrix temperature profiles, the concentration profile of product gas as well as the distribution of the fractional conversion of solid reactant were predicted under various conditions. The results are useful in the conceptual design and operation of packed bed reactor that is involved with strongly endothermic reactions.更多还原