The influence of frictional packing limit ( FPL ) on prediction of hydrodynamics and performance of fluidized bed reactors was studied. Dense gas-solid flows in non-reactive (under isothermal cold and at elevated temperatures) and reactive atmospheres (fluidized bed gasifier) were simulated using Eulerian-Eulerian methodology considering a range of values for FPL . Simulations under cold flow conditions were conducted to establish a range of FPL values that provides physically realistic predictions. It is noticed that bed pressure drop increases with increasing value of FPL when superficial gas velocity ( U ) is less than or equal to the minimum fluidization velocity. For larger values of U , predicted pressure drop is unaffected by the choice of value of FPL . However, in these cases, the distribution of particles, their velocities and bubbling behavior are significantly affected by FPL . Effect of FPL at elevated temperatures is similar to the one observed at cold flow conditions. It is further noticed that FPL not only affects the predictions on bed hydrodynamics but also has profound influence on reactive flow characteristics such as bed temperature and product gas composition. Sensitivity analysis under cold flow conditions could reveal better predictions when the ratio of FPL to close packing limit is chosen between 0.9 and 0.97.

中文翻译：

---

摩擦堆积极限对气固流化床流体力学和性能的影响

研究了摩擦堆积极限（FPL）对流化床反应器流体动力学和性能预测的影响。考虑到一系列 FPL 值，使用欧拉-欧拉方法模拟非反应性（在等温低温和高温下）和反应性气氛（流化床气化器）中的密集气固流。在冷流条件下进行模拟以建立一系列 FPL 值，提供物理上真实的预测。注意到当表观气速 (U) 小于或等于最小流化速度时，床压降随着 FPL 值的增加而增加。对于较大的 U 值，预测的压降不受 FPL 值选择的影响。然而，在这些情况下，粒子的分布，它们的速度和冒泡行为受到 FPL 的显着影响。FPL 在升高的温度下的效果类似于在冷流条件下观察到的效果。进一步注意到，FPL 不仅影响床层流体动力学的预测，而且对反应流特性如床层温度和产物气体组成有深远的影响。当 FPL 与密堆积极限的比率选择在 0.9 和 0.97 之间时，冷流条件下的灵敏度分析可以揭示更好的预测。进一步注意到，FPL 不仅影响床层流体动力学的预测，而且对反应流特性如床层温度和产物气体组成有深远的影响。当 FPL 与密堆积极限的比率选择在 0.9 和 0.97 之间时，冷流条件下的灵敏度分析可以揭示更好的预测。进一步注意到，FPL 不仅影响床层流体动力学的预测，而且对反应流特性如床层温度和产物气体组成有深远的影响。当 FPL 与密堆积极限的比率选择在 0.9 和 0.97 之间时，冷流条件下的灵敏度分析可以揭示更好的预测。